WO2021151890A1

WO2021151890A1 - Devices and method for transmitting a multicast message in a non-coordinated communications system

Info

Publication number: WO2021151890A1
Application number: PCT/EP2021/051756
Authority: WO
Inventors: Gerd Kilian; Josef Bernhard; Thomas Kauppert; Hristo PETKOV; Johannes WECHSLER; Jakob KNEISSL; Raphael MZYK; Klaus Gottschalk; Dominik Soller; Michael Schlicht
Original assignee: Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.; Diehl Metering Gmbh
Priority date: 2020-01-31
Filing date: 2021-01-26
Publication date: 2021-08-05
Also published as: DE102020201209A1

Abstract

Embodiments of the proposed invention include a subscriber of an uncoordinated communications system, wherein the subscriber is configured to receive and decode a first data packet of a plurality of data packets of a multicast data transmission, wherein the plurality of data packets are multiple transmissions of the same data packet, wherein the subscriber is configured to determine whether the subscriber fulfills a receiving criterion, wherein the subscriber is configured such that, if the subscriber fulfills the receiving criterion, it will receive no further data packets of the plurality of data packets of the multicast data transmission, wherein the subscriber is configured such that, if the subscriber does not fulfill the receiving criterion, it receives at least one second data packet of the plurality of data packets of the multicast data transmission.

Description

Devices and methods for transmitting a multicast message in a non-coordinated communication system

description

Embodiments of the present invention relate to a wireless communication system with a multiplicity of uncoordinated sending subscribers, and in particular to the transmission of a multicast message (point-to-multipoint message) in such a communication system. Some exemplary embodiments relate to a schedule for maintaining or utilizing a low duty cycle (e.g. 10%) (low duty cycle scheduling).

In typical radio networks (or wireless communication systems), such as GSM (GSM = Global System for Mobile Communications), there is a coordinating entity which, if necessary, makes radio resources available to the subscribers of the radio network that are exclusively available to the respective subscriber.

This ensures that each participant can transmit their data in a radio resource reserved exclusively for them. This avoids interference between the participants in a radio network and thus maximizes throughput.

In such radio networks, the participants are usually coordinated with regard to radio resources by means of so-called beacons, to which the participants in the radio network listen. The signaling of the radio resources in these beacons makes it necessary for all participants to receive and evaluate them in order to be able to subsequently receive or send data. The power consumption of a participant who rarely accesses the channel is therefore very high.

Another approach, on the other hand, is a non-coordinated radio network in which the subscribers transmit their data to the recipient on a contention-based basis. This means that a beacon does not have to be continuously received, which signals when which subscriber is allowed to transmit on which frequency. This reduces the power consumption of the participants, as they only have to be activated when required. However, this method has the disadvantage that it can lead to interference between the participants in the radio network. However, this disadvantage can be reduced by using "Telegram Splitting Multiple Access" (TSMA) [4], which enables throughputs similar to those achieved with a coordinated system.

With “Telegram Splitting Multiple Access” (TSMA), the transmission of a message (data packet) is divided into a number of short sub-data packets (bursts), between which there are transmission-free time intervals of different lengths. The sub-data packets are distributed according to a pseudo-random principle both over time and over the available frequency channels, as is shown by way of example in FIG.

In detail, FIG. 1 shows in a diagram an occupancy of a frequency band of a TSMA-based communication system during the transmission of a data packet divided into a plurality of sub-data packets 10, the plurality of sub-data packets being distributed in time and frequency. In FIG. 1, the ordinate describes the frequency (frequency channels) and the abscissa describes the time. In other words, FIG. 1 shows the principle of data transmission according to the TSMA method.

It was shown in [1] that the TSMA method can achieve a greater capacity in data transmission than when transmitting a data packet in a coherent block, ie without dividing it into sub-data packets 10. In order to obtain the greatest possible system capacity, As many different time and / or frequency hopping patterns as possible should be used [3]. The total number of time and / or frequency hopping patterns used should be finite and come from a stock of time and / or frequency hopping patterns known in advance.

As a result of the competition-based access to the channel at random times, an asynchronous transmission occurs, as is shown by way of example in FIG. 2 for a communication system without TSMA.

In detail, FIG. 2 shows in a diagram an occupancy of a frequency band of a competition-based communication system during the transmission of several uplink messages 12 and several downlink messages 14. In FIG. 2, the abscissa describes the frequency and the ordinate describes the time. In other words, FIG. 2 shows a diagram of a transmission channel in a non-coordinated communication system. As a rule, there are several participants (eg end points) in a non-coordinated communication system that communicate with a base station. The transmission of a message from a subscriber to the base station involves the uplink and, in the opposite direction, the downlink.

For reasons of energy efficiency, the participants usually only switch their transceiver module on when they want to send a message. It is therefore not possible to receive one of the downlink messages 14, as shown in FIG. 2.

To solve this problem, it was defined in [4] that the subscriber waits a fixed time after sending an uplink message in order to then open a reception window for a downlink message. The base station can therefore only send a downlink message to this subscriber at a specific point in time.

Typically, the downlink to the participants for whom the uncoordinated transmission is used is used for messages that are to be transmitted to several participants, e.g. software updates or time sync commands.

Due to the asynchronous network approach from [4] (competition-based access), each participant must now be informed of the downlink message separately. This is a problem especially in large radio networks in which there are a large number of participants, since with a large number of participants it would take a very long time until all participants have received the data.

In coordinated communication systems it is possible to signal a point-to-multipoint message (multicast message) from the base station to the subscribers in a beacon. All participants who have received the beacon can then also receive the corresponding resources of the multicast message.

The present invention is therefore based on the object of enabling the transmission of a point-to-multipoint message in a communication system with a large number of uncoordinated sending participants.

This problem is solved by the independent patent claims.

Advantageous further developments can be found in the dependent claims, Embodiments create a subscriber of an uncoordinated communication system [e.g. wherein the subscriber is configured to send data in an uncoordinated manner in relation to other subscribers and / or a base station of the communication system], the communication system communicating wirelessly in a frequency band [e.g. ISM band] which is from a plurality of mutually uncoordinated communication systems is used, the subscriber being configured to receive and decode a first data packet of a plurality of data packets of a data transmission [e.g. multicast data transmission or downlink data transmission] [e.g. a base station of the communication system], the A plurality of data packets are multiple transmissions of the same data packet, the subscriber being configured, if the subscriber meets a reception criterion, not to receive any further data packets of the plurality of data packets of the data transmission, the subscriber is configured to, if the subscriber does not meet the reception criterion, to receive at least one second data packet of the plurality of data packets of the data transmission.

In exemplary embodiments, the data transmission is a downlink data transmission.

In exemplary embodiments, the data transmission is point-to-multipoint data transmission.

In exemplary embodiments, the subscriber is configured to determine whether the subscriber meets the reception criterion.

In embodiments, the reception criterion is at least one of a successful decoding of the first data packet, a signal-to-noise ratio of a received signal of the first data packet or a previous data packet, a received field strength [e.g. RSSI] of a received signal of the first data packet or of a previous data packet. a successful redundancy check [e.g. CRC (Cyclic Redundancy Check) of the first data packet.

In exemplary embodiments, a downlink data transmission preceding the data transmission has information on whether the subscriber meets the reception criterion. For example, based on the uplink data transmission and / or a previous uplink data transmission, the base station can determine whether the subscriber meets the reception criterion, e.g. based on an SNR, degree of interference, etc.

In exemplary embodiments, the plurality of data packets are symbolically identical.

In embodiments, the plurality of data packets have the same useful data.

In exemplary embodiments, the plurality of data packets have the same error protection data or different error protection data.

In embodiments, at least one first data packet of the plurality of data packets has a higher code rate and / or data rate than the other data packets of the plurality of data packets.

For example, a kth data packet of the plurality of data packets can have a lower code rate and / or data rate than the k-1th data packet of the plurality of data packets, where k is a natural number greater than or equal to two.

In exemplary embodiments, the subscriber is configured to switch from a normal operating mode to an energy-saving mode if the subscriber meets the reception criterion.

In exemplary embodiments, the plurality of data packets are each provided with error protection data, the subscriber being configured to combine the first data packet and the at least one second data packet if the subscriber does not meet the reception criterion and decoding of the first data packet was unsuccessful to achieve a higher code gain in the decoding by the combination of the first data packet and the at least one second data packet.

In exemplary embodiments, the subscriber is configured to receive a downlink data transmission from the base station in a time-synchronized manner with a sent uplink data transmission to a base station of the communication system, the downlink data transmission having signaling information, the subscriber being configured to based on the Signaling information at least the first data packet To receive point-to-multipoint data transmission [e.g. multicast data transmission] from the base station.

In exemplary embodiments, the signaling information includes information about a point in time of the point-to-multipoint data transmission.

For example, the information about the point in time can be an absolute point in time, a relative point in time (e.g. a defined time span between the downlink data transmission and the point-to-multipoint data transmission) or information from which the absolute or relative point in time can be derived, such as eg a number of clock cycles of an oscillator of the participant.

In embodiments, the signaling information further comprises information about a frequency channel [e.g. of the frequency band used by the communication system] of point-to-multipoint data transmission.

For example, the information about the frequency channel can be an absolute frequency channel or a relative frequency channel (e.g. a distance between a frequency channel of the downlink data transmission and a frequency channel of the point-to-multipoint data transmission).

In exemplary embodiments, the subscriber is a telegram splitting-based subscriber, with one data packet of the plurality of data packets being a sub-data packet of a plurality of sub-data packets, each of which has a part of the point-to-multipoint data transmission and which is each shorter than the Point-to-multipoint data transmission and which are transmitted in a distributed manner in accordance with a time and / or frequency hopping pattern, the other data packets of the plurality of data packets being retransmissions of the same sub-data packet.

In exemplary embodiments, a data packet of the plurality of data packets is a radio burst of the ETSI TS 103 357 standard, the other data packets of the plurality of data packets being repeated transmissions of the same radio burst.

In embodiments, the participant is a sensor node or actuator node.

In exemplary embodiments, the participant is battery-operated and / or wherein the participant has an energy harvesting element for generating electrical energy. Further exemplary embodiments create a communication system with at least one subscriber like one of the exemplary embodiments described herein and a base station which is configured to send out the plurality of data packets of the data transmission.

Further embodiments provide a subscriber to an uncoordinated communication system [e.g. wherein the subscriber is configured to send data in an uncoordinated manner with respect to other subscribers and / or a base station of the communication system], the communication system operating in a frequency band [e.g. ISM Band] communicates wirelessly, which is used by a plurality of mutually uncoordinated communication systems, wherein the subscriber is configured to receive a downlink data transmission from the base station synchronized in time to a sent uplink data transmission to the base station of the communication system, the downlink -Data transmission comprises a first signaling information and a second signaling information, wherein the first signaling information signals a first point-to-multipoint data transmission, and wherein the second signaling information signals a second point-to-multipoint data transmission, [e.g. wherein the first point-to-multipoint data transmission and the second point-to-multipoint data transmission are different point-to-multipoint data transmissions], wherein the subscriber is configured to based on the downlink data transmission or a previous downlink data transmission or a previous point-to-multipoint data transmission, a reception quality [e.g. Link budget or sensitivity] [e.g. of the respective data transmission from the base station to the subscriber], the subscriber being configured to select one of the first point-to-multipoint data transmission based on the first as a function of the determined reception quality

Signaling information, and the second point-to-multipoint data transmission based on the first

Receive signaling information.

In exemplary embodiments, the subscriber is configured to receive the first point-to-multipoint data transmission based on the first signaling information if the determined reception quality meets a first reception quality criterion, the subscriber being configured to, if the determined reception quality, the first reception quality criterion not fulfilled or the determined reception quality meets a second reception quality criterion, the second point-to-multipoint data transmission based on the second signaling information, wherein the first reception quality criterion and the second reception quality criterion are different.

In exemplary embodiments, the first reception quality criterion indicates that the reception quality is greater than or equal to a reception quality threshold or lies within a first reception quality range.

In exemplary embodiments, the second reception quality criterion indicates that the reception quality is less than the reception quality threshold or lies within a second reception quality range, the first reception quality range and the second reception quality range being different.

In embodiments, the first reception quality criterion is given [e.g. fixed].

In exemplary embodiments, the downlink data transmission has information about the first reception quality criterion.

In embodiments, the second reception quality criterion is given [e.g. fixed].

In exemplary embodiments, the downlink data transmission has information about the second reception quality criterion.

In exemplary embodiments, the first point-to-multipoint data transmission and the second point-to-multipoint data transmission differ with regard to at least one

Transmission times,

Transmission frequencies, frequency and / or time hopping patterns used.

In exemplary embodiments, the first point-to-multipoint data transmission and the second point-to-multipoint data transmission have different data rates.

For example, a data rate of the first point-to-multipoint data transmission can be greater than a data rate of the second point-to-multipoint data transmission. In exemplary embodiments, the first point-to-multipoint data transmission and the second point-to-multipoint data transmission are coded differently.

For example, a code rate of the first point-to-multipoint data transmission can be greater than a code rate of the second point-to-multipoint data transmission.

In exemplary embodiments, the first point-to-multipoint data transmission and the second point-to-multipoint data transmission have the same useful data.

In exemplary embodiments, the first point-to-multipoint data transmission has a plurality of first sub-data packets which are transmitted in a time and / or frequency distributed according to a time and / or frequency hopping pattern, and / or the second point-to-point Multipoint data transmission has a plurality of second sub-data packets which are transmitted in a time and / or frequency distributed according to a time and / or frequency hopping pattern.

In exemplary embodiments, the plurality of first sub-data packets and / or the plurality of sub-data packets are radio bursts according to the ETS1 TS 103 357 standard [e.g. and like to be transferred to the same].

In embodiments, the participant is a sensor node or actuator node.

In embodiments, the participant is battery-operated.

In exemplary embodiments, the subscriber has an energy harvesting element for generating electrical energy.

Further embodiments create a base station of an uncoordinated communication system, the communication system communicating wirelessly in a frequency band [e.g. ISM band] that is used by a plurality of mutually uncoordinated communication systems, the base station being configured to allow uplink data transmission from a subscriber in the communication system to receive, wherein the uplink data transmission is uncoordinated, wherein the base station is configured to send a downlink data transmission to the subscriber in a time-synchronized manner to the received uplink data transmission of the subscriber, the downlink data transmission having a first signaling information and a second signaling information having, wherein the first signaling information a signaling subsequent first point-to-multipoint data transmission, and wherein the second signaling information signals a subsequent second point-to-multipoint data transmission, the base station being configured to transmit the first point-to-multipoint data transmission in accordance with the first signaling information and to transmit the second point-to-multipoint data transmission in accordance with the second signaling information, the second point-to-multipoint data transmission having a lower code rate and / or data rate than the first point-to-multipoint data transmission in order to achieve a probability of passage the second point-to-multipoint data transmission compared to the first point-to-multipoint data transmission in relation to subscribers of the communication system who do not meet a reception quality criterion.

In exemplary embodiments, the reception quality criterion indicates that a reception quality of the respective subscriber of the communication system is greater than or equal to a reception quality threshold or lies within a first reception quality range.

In exemplary embodiments, the base station is configured to provide the downlink data transmission with information about the reception quality criterion.

In exemplary embodiments, the reception quality criterion is a first reception quality criterion, the base station being configured to provide the downlink data transmission with information about a second reception quality criterion, the second reception quality criterion indicating that a reception quality of the respective subscriber of the communication system is lower than the reception quality threshold or lies within a second reception quality range, the first reception quality range and the second reception quality range being different.

Transmission times,

Transmission frequencies, frequency and / or time hopping patterns used.

Further exemplary embodiments create a communication system with at least one subscriber like one of the exemplary embodiments described herein and a base station like one of the exemplary embodiments described herein.

Further embodiments create a base station of an uncoordinated communication system, the communication system communicating wirelessly in a frequency band [e.g. ISM band] that is used by a plurality of mutually uncoordinated communication systems, the base station being configured to allow uplink data transmission from a subscriber in the communication system to receive, the uplink data transmission being uncoordinated, the uplink data transmission having information about a reception quality [e.g. link budget or sensitivity] of the subscriber [e.g. in relation to a [e.g. previous] data transmission of the base station] or the base station being configured in order to estimate a reception quality of the subscriber based on the uplink data transmission, the base station being configured to perform a downlink data transmission in a time-synchronized manner with the received uplink data transmission of the subscriber. d to send em subscriber, wherein the base station is configured to provide the downlink data transmission depending on the reception quality of the subscriber [eg either] with a first signaling information or a second signaling information, the first signaling information a subsequent first point-to-multipoint Data transmission signals, and wherein the second signaling information signals a subsequent second point-to-multipoint data transmission, wherein the base station is configured to carry out the first point-to-multipoint data transmission to send in accordance with the first signaling information and to send the second point-to-multipoint data transmission in accordance with the second signaling information.

In exemplary embodiments, the base station is configured to provide the downlink data transmission with the first signaling information if the subscriber's reception quality meets a first reception quality criterion, the base station being configured to, if the subscriber's reception quality does not meet the first reception quality criterion or the Receipt quality of the subscriber meets a second reception quality criterion to provide the downlink data transmission with the second signaling information.

In embodiments, the first reception quality criterion is given [e.g. fixed].

In embodiments, the base station is configured to dynamically adapt the first reception quality criterion [e.g. based on a current level of interference in the radio channel].

In embodiments, the second reception quality criterion is given [e.g. fixed].

In embodiments, the base station is configured to dynamically adapt the second reception quality criterion [e.g. based on a current level of interference in the radio channel].

In exemplary embodiments, the first point-to-multipoint data transmission and the second point-to-multipoint data transmission differ with regard to at least one Transmission times,

Transmission frequencies, frequency and / or time hopping patterns used.

For example, a data rate of the first point-to-multipoint data transmission can be greater than a data rate of the second point-to-multipoint data transmission.

In exemplary embodiments, the first point-to-multipoint data transmission and the second point-to-multipoint data transmission are coded differently.

In exemplary embodiments, the first point-to-multipoint data transmission has a plurality of first sub-data packets, which are transmitted in a time and / or frequency distributed according to a time and / or frequency hopping pattern, and / or the second point-to-point Multipoint data transmission has a plurality of second sub-data packets which are transmitted in a time and / or frequency distributed according to a time and / or frequency hopping pattern.

In exemplary embodiments, the plurality of first sub-data packets and / or the plurality of sub-data packets are radio bursts like the ETSI TS 103 357 [e.g. and like to be transferred to the same].

Further exemplary embodiments create a communication system with a base station like one of the exemplary embodiments described herein and at least one subscriber, the at least one subscriber being configured to receive the downlink data transmission from the base station in a time-synchronized manner with the sent uplink data transmission to the base station of the communication system , wherein the downlink data transmission is provided with signaling information from the first signaling information and the second signaling information, the first signaling information signaling the first point-to-multipoint data transmission, and wherein the second signaling information signals the second point-to-point data transmission, the at least one subscriber being configured to receive the respective point-to-multipoint data transmission based on the signature information with which the downlink data transmission is provided .

Further embodiments provide a base station of an uncoordinated communication system, the communication system operating in a frequency band [e.g. ISM band] which is used by a plurality of mutually uncoordinated communication systems, the base station being configured to initiate a first point-to-multipoint data transmission [e.g. to a plurality of subscribers], wherein the base station is configured to abort or pause the transmission of the first point-to-multipoint data transmission if at least one second data transmission is carried out at the time of the transmission of the first point-to-multipoint data transmission , which has a higher priority than the first point-to-multipoint data transmission, is pending transmission, and wherein the base station is configured to transmit the at least one second data transmission.

In embodiments, the at least one second data transmission is a second point-to-multipoint data transmission.

In exemplary embodiments, the at least one second data transmission is one or more

Point-to-point data transfers [e.g. Uplink data transmissions and / or downlink data transmissions],

In embodiments, the base station is configured to resume the transmission of the first point-to-multipoint data transmission after the transmission of the at least one second data transmission, provided that there is an available duty cycle of the base station for resuming the first point-to-multipoint data transmission is sufficient.

Further exemplary embodiments create a base station of an uncoordinated communication system, the communication system communicating wirelessly in a frequency band [e.g. ISM band] which is used by a plurality of mutually uncoordinated communication systems, the base station being configured for a second point-to-multipoint data transmission [For example, to a plurality of subscribers of the communication system] to transmit within a transmission interval, wherein the base station is further configured to within the Transmission interval to transmit at least part of a first point-to-multipoint data transmission, provided that a duty cycle of the base station for the transmission of the at least part of the first point-to-multipoint data transmission

Data transfer is sufficient.

In exemplary embodiments, the second point-to-multipoint data transmission has a higher priority than the first point-to-multipoint data transmission.

In exemplary embodiments, the plurality of first sub-data packets and / or the plurality of sub-data packets are radio bursts like the ETSI TS 103 357 [e.g. and like to be transferred to it].

Further exemplary embodiments create a communication system with a base station like one of the exemplary embodiments described herein and at least one subscriber, wherein the at least one subscriber is configured to the first point-to-multipoint data transmission and / or the second point-to-multipoint data transmission receive.

Further exemplary embodiments create a base station of an uncoordinated communication system, the communication system communicating wirelessly in a frequency band [e.g. ISM band] which is used by a plurality of mutually uncoordinated communication systems, the base station being configured to carry out point-to-multipoint data transmission at least two point-to-multipoint partial data transmissions, wherein the base station is configured to at least one first point-to-multipoint partial data transmission of the at least two point-to-multipoint partial data transmissions to a plurality of subscribers of the Communication system, the base station being configured to receive acknowledgments of receipt from at least a part of the plurality of subscribers, the acknowledgments of receipt confirming successful receipt of the at least one first point-to-multipoint partial data transmission, the base station configuring rt is to determine a measure of success [e.g. success rate] [e.g. the Transmission of the at least one first point-to-multipoint partial data transmission], wherein the base station is configured to, if the measure of success meets a success criterion, to at least one second point-to-multipoint partial data transmission of the at least two points to transmit multipoint partial data transmissions to the plurality of subscribers of the communication system.

In exemplary embodiments, the base station is configured, if the measure of success does not meet the success criterion, to abort the transmission of the point-to-multipoint data transmission or to retransmit the first point-to-multipoint partial data transmission.

Further exemplary embodiments provide a communication system having a base station, one of the exemplary embodiments described herein and a plurality of subscribers configured to receive the point-to-multipoint data transmission.

Further embodiments provide a method for receiving a data transmission in an uncoordinated communication system, wherein the communication system is in a frequency band [e.g. ISM Band] communicates wirelessly, which is used by a number of mutually uncoordinated communication systems. The method comprises a step of receiving and decoding at least a first data packet of a plurality of data packets of the data transmission [e.g. Multicast data transmission or downlink data transmission] [e.g. a base station of the communication system], wherein the plurality of data packets are multiple transmissions of the same data packet. Furthermore, the method comprises a step of receiving, if a receiving criterion is met, not to receive any further data packets of the plurality of data packets of the data transmission. The method further comprises a step of receiving, if the receiving criterion is met, at least one further data packet of the plurality of data packets of the data transmission.

Further embodiments create a method for receiving a point-to-multipoint data transmission in an uncoordinated communication system, the communication system communicating wirelessly in a frequency band [eg ISM band] which is used by a plurality of mutually uncoordinated communication systems. The method comprises a step of sending an uplink data transmission. Furthermore, the method comprises a step of receiving, synchronized in time with the sent uplink data transmission, a downlink data transmission, the downlink data transmission being a first Signaling information and a second signaling information, wherein the first signaling information signals a first point-to-multipoint data transmission, and wherein the second signaling information signals a second point-to-multipoint data transmission, [e.g. wherein the first point-to-multipoint data transmission and the second point-to-multipoint data transmission are different point-to-multipoint data transmissions]. The method further comprises a step of determining a reception quality [eg Unk budget or sensitivity] based on the downlink data transmission or a previous downlink data transmission or a previous point-to-multipoint data transmission. The method further comprises a step of receiving, as a function of the determined reception quality, one of the first point-to-multipoint data transmission based on the first

Signaling information.

Further exemplary embodiments create a method for sending point-to-multipoint data transmissions in an uncoordinated communication system, the communication system communicating wirelessly in a frequency band [eg ISM band] which is used by a plurality of communication systems that are uncoordinated with one another. The method comprises a step of receiving an uplink data transmission, the uplink data transmission being uncoordinated. Furthermore, the method comprises a step of transmitting, synchronized in time with the received uplink data transmission, a downlink data transmission, the downlink data transmission having a first signaling information item and a second signaling information item, the first signaling information item being a subsequent first point-to-multipoint Signaled data transmission, and the second signaling information signaling a subsequent second point-to-multipoint data transmission. The method further comprises a step of sending the first point-to-multipoint data transmission in accordance with the first signaling information. The method further comprises a step of sending the second point-to-multipoint data transmission in accordance with the second signaling information, the second point-to-multipoint data transmission having a lower code rate and / or data rate than the first point-to-multipoint data transmission , in order to increase a probability of passage of the second point-to-multipoint data transmission compared to the first point-to-multipoint data transmission. Further exemplary embodiments provide a method for sending point-to-multipoint data transmissions in an uncoordinated communication system, the communication system communicating wirelessly in a frequency band [eg ISM band] which is used by a plurality of mutually uncoordinated communication systems. The method includes a step of receiving an uplink

Data transmission, whereby the uplink data transmission is uncoordinated. The method further comprises a step of extracting information about a reception quality [e.g. Link budget or sensitivity] from the uplink data transmission or estimating a reception quality based on the uplink data transmission. Furthermore, the method comprises a step of sending, synchronized in time with the received uplink

Data transmission, a downlink data transmission, the downlink data transmission depending on the reception quality [e.g. either] is provided with first signaling information or second signaling information, the first signaling information signaling a subsequent first point-to-multipoint data transmission, and the second signaling information signaling a subsequent second point-to-multipoint data transmission. The method further comprises a step of sending the first point-to-multipoint data transmission in accordance with the first signaling information. The method further comprises a step of sending the second point-to-multipoint data transmission in accordance with the second signaling information.

Further embodiments provide a method of transmitting point-to-multipoint data transmissions in an uncoordinated communication system, the communication system operating in a frequency band [e.g. ISM Band] communicates wirelessly, which is used by a number of mutually uncoordinated communication systems. The method includes a step of transmitting a first point-to-multipoint data transmission. The method further comprises a step of aborting or pausing the transmission of the first point-to-multipoint data transmission if at least one second data transmission which has a higher priority than the first point at the time of the transmission of the first point-to-multipoint data transmission -to- multipoint data transmission, pending transmission. The method further comprises a step of transmitting the second data transmission.

Further exemplary embodiments create a method for transmitting point-to-multipoint data transmissions in an uncoordinated communication system, the communication system communicating wirelessly in a frequency band [eg ISM band] which is one of a plurality of mutually uncoordinated communication systems is being used. The method comprises a step of transmitting a second point-to-multipoint data transmission within a transmission interval. The method further comprises a step of transmitting within the transmission interval at least part of a first point-to-multipoint data transmission, provided that a duty cycle of the base station within the transmission interval is sufficient for the transmission of the at least part of the first point-to-multipoint data transmission is.

Further embodiments provide a method of transmitting point-to-multipoint data transmission in an uncoordinated communication system, the communication system operating in a frequency band [e.g. ISM Band] communicates wirelessly, which is used by a number of mutually uncoordinated communication systems. The method comprises a step of dividing the point-to-multipoint data transmission into at least two point-to-multipoint partial data transmissions. The method further comprises a step of transmitting at least one first point-to-multipoint partial data transmission of the at least two point-to-multipoint partial data transmissions to a plurality of subscribers in the communication system. The method further comprises a step of receiving acknowledgments of receipt from at least some of the plurality of subscribers, the acknowledgments of receipt confirming successful receipt of the at least one first point-to-multipoint partial data transmission. The method further comprises a step of determining, based on a number of receipts received, a measure of success [e.g. Success rate] [e.g. the transmission of the at least one first point-to-multipoint partial data transmission]. The method further comprises a step of transmitting, if the measure of success meets a success criterion, at least one second point-to-multipoint partial data transmission of the at least two point-to-multipoint partial data transmissions to the plurality of subscribers in the communication system.

Further exemplary embodiments create a computer program for carrying out a method like one of the exemplary embodiments described herein, when the computer program runs on a computer, microprocessor or software-based receiver [SDR, Software Defined Radio].

Exemplary embodiments of the present invention are described in more detail with reference to the accompanying figures. Show it:

Fig. 1 in a diagram an occupancy of a frequency band of a TSMA-based communication system when transmitting a to a plurality of sub- Data packets divided into data packets, the plurality of sub-data packets being distributed in time and frequency,

2 shows in a diagram an occupancy of a frequency band of a competition-based communication system during the transmission of several uplink messages and several downlink messages,

3 shows a schematic view of a communication system with a base station and one or more participants as well as two other communication systems, according to an exemplary embodiment of the present invention,

FIG. 4 shows a schematic block diagram of the base station and one of the subscribers of the communication system shown in FIG. 3, according to an exemplary embodiment of the present invention.

Fig. 5 is a diagram of an occupancy of a frequency band of the

Communication system when carrying out several uplink data transmissions and downlink data transmissions between the base station and several of the subscribers as well as a point-to-multipoint data transmission from the base station to several of the subscribers, according to an exemplary embodiment of the present invention,

6 shows a schematic block diagram of a subscriber and a base station, according to an exemplary embodiment of the present invention,

7 shows a diagram of an occupancy of the frequency band of the

Communication system when performing an uplink data transmission, a downlink data transmission and a point-to-multipoint data transmission, according to an embodiment of the present invention,

8 shows a diagram of an occupancy of the frequency band of the

Communication system when performing a first uplink data transmission, a first downlink data transmission, a second uplink data transmission, a second downlink data transmission and a point to multipoint data transmission, according to an embodiment of the present invention,

9 shows a diagram of an occupancy of the frequency band of the

Communication system when performing an uplink data transmission, a downlink data transmission, a transmission of a support beacon as a further data transmission, and a point-to-multipoint data transmission, according to an embodiment of the present invention,

10 shows a schematic block diagram of a subscriber and a base station, according to an exemplary embodiment of the present invention,

11 shows a diagram of an occupancy of the frequency band of the

Communication system in a point-to-multipoint data transmission and a transmission of several support beacons in advance of the point-to-multipoint data transmission, according to an embodiment of the present invention,

FIG. 12 shows an occupancy of a frequency band of the communication system in FIG

Transmission of a point-to-multipoint data transmission and a transmission of a plurality of support beacons, wherein useful data of the point-to-multipoint data transmission are divided into a plurality of useful data parts and are each transmitted together with one of the support beacons, according to an embodiment of the present invention,

13 shows a diagram of an occupancy of the frequency band of the

Communication system in the transmission of three point-to-multipoint data transmissions for three different groups of subscribers of the communication system as well as a common transmission of support beacons for the three different groups of subscribers of the communication system, according to an embodiment of the present invention,

14 shows a schematic block diagram of a base station and a subscriber, for example of the communication system shown in FIG. 3, according to an exemplary embodiment of the present invention; 15 shows a schematic view of a transmission of eight data packets, a first data packet being an initial transmission of a so-called radio burst, and the other data packets being repeated transmissions of the same radio burst, according to an exemplary embodiment of the present invention;

Fig. 16 is a schematic block diagram of a base station and a subscriber, e.g., of the communication system shown in Fig. 3, according to a

Embodiment of the present invention;

17 shows a schematic view of an occupancy of a communication channel during the transmission of two multicast data transmissions for subscribers with good (or better) reception conditions and subscribers with poor (or worse) reception conditions, according to an exemplary embodiment of the present invention;

Fig. 18 is a schematic block diagram of a base station and a subscriber, e.g., of the communication system shown in Fig. 3, according to a

Embodiment of the present invention;

19 shows a schematic view of an occupancy of a communication channel during the transmission of a first multicast data transmission and a second multicast data transmission, the second multicast data transmission having a higher priority than the first multicast data transmission, according to an exemplary embodiment;

20 shows a schematic view of an occupancy of a communication channel during the transmission of a multicast data transmission of a base station, the multicast data transmission being transmitted divided into at least two multicast partial data transmissions, with at least one first multicast partial data transmission after the transmission Acknowledgments of receipt are transmitted from subscribers who confirm successful receipt of the at least one first multicast partial data transmission, according to an exemplary embodiment;

21 shows a flow diagram of a method for receiving a point-to-multipoint data transmission in an uncoordinated communication system, according to an exemplary embodiment; 22 shows a flow diagram of a method for receiving a point-to-multipoint data transmission in an uncoordinated communication system, according to an exemplary embodiment of the present invention;

23 shows a flow diagram of a method for sending point-to-multipoint data transmissions in an uncoordinated communication system, according to an exemplary embodiment of the present invention;

24 shows a flow diagram of a method for sending point-to-multipoint data transmissions in an uncoordinated communication system, according to an exemplary embodiment of the present invention;

25 shows a flow diagram of a method for transmitting point-to-multipoint data transmissions in an uncoordinated communication system, according to an exemplary embodiment of the present invention;

26 shows a flow diagram of a method for transmitting point-to-multipoint data transmissions in an uncoordinated communication system, according to an exemplary embodiment of the present invention; and

27 shows a flow diagram of a method 270 for transmitting a point-to-multipoint data transmission in an uncoordinated communication system, according to an exemplary embodiment.

In the following description of the exemplary embodiments of the present invention, elements that are the same or have the same effect are provided with the same reference symbols in the figures, so that their descriptions can be interchanged with one another.

Before detailed exemplary embodiments of a subscriber (e.g. end point) and a base station are described in more detail, the underlying communication system in which the subscriber or the base station can be used will first be explained in more detail with reference to FIGS. 3 and 4.

3 shows a schematic view of a communication system 100 and two other communication systems 101 and 102, according to an exemplary embodiment of the present invention. The communication system 100 can have a base station 104 (or optionally several base stations) and one or more subscribers (eg endpoints) 106_1-106_n, where n is a natural number greater than or equal to one. In the exemplary embodiment shown in FIG. 3, the communication system 100 has five participants 106_1-106_5 for illustration, but the communication system 104_1 can just as well have 1, 10, 100, 1,000, 10,000 or even 100,000 participants.

The communication system 100 can be designed to wirelessly communicate in a frequency band (e.g. a license-free and / or license-free frequency band, such as the ISM band) which is used for communication by a plurality of communication systems that are not coordinated with one another, as shown in FIG. 3 is indicated by way of example by the other communication systems 101 and 102.

The frequency band used by the communication system 100 can have a significantly (e.g. by at least a factor of 5 (or 10)) greater bandwidth than the reception filters of the receivers (receivers or transceivers) of the subscribers 106_1-106_n.

The subscribers 106_1-106_n of the communication system 100 can be designed to send data in an uncoordinated manner (e.g. and asynchronously) with respect to other subscribers and / or the base station 104 of the communication system 100. For example, the participants 106_1-106_n can be designed to send data at predetermined rough intervals (e.g. hourly, daily, weekly, half-yearly, yearly, etc.) or in response to an external event (e.g. deviation of a sensor value from a target value). Here, the exact transmission time and / or the exact frequency or the exact frequency channel of the frequency band for transmitting the data can be determined by the respective subscriber himself. The respective subscriber sends the data regardless of whether another subscriber and / or the base station 104 is transmitting data at the same point in time or overlapping in time and / or on the same frequency or the same frequency channel of the frequency band.

The transmission of data (e.g. a data packet) from one of the subscribers 106_1-106_n, e.g. from subscriber 106_1, to the base station 104 is referred to as uplink data transmission, while the transmission of data from the base station 104 to one of the subscribers 106_1-106_n , for example to the subscriber 106_1, is referred to as downlink data transmission. The uplink data transmission accordingly designates (or comprises) the transmission of an uplink data packet (or an uplink message) from the respective subscriber to the base station 104, while the downlink data transmission denotes (or includes) the transmission of a downlink data packet (or a downlink message) from the base station 104 to the respective subscriber.

Since the uplink data transmission of the respective subscriber 106_1-106_n is uncoordinated and the transceiver of the respective subscriber 106_1-106_n is usually only activated for data transmission, the downlink data transmission to the respective subscriber is synchronized in time with the uplink data transmission , ie after a predefined time and / or frequency after the uplink data transmission, the respective subscriber activates his transceiver for a predefined time interval (receiving window) in order to receive the downlink data transmission that is responding to the base station 104 (e.g. in response auf) is sent to the uplink data transmission exactly within this time interval. Optionally, the downlink data transmission to the respective subscriber can also be synchronized in frequency with the respective uplink data transmission, e.g. on the same frequency (in the same frequency channel) or with a predetermined frequency spacing.

This has the advantage that subscribers 106_1-106_n only have to activate their transceiver units for the respective data transmission (uplink data transmission and / or downlink data transmission) (e.g. in a normal operating mode), while the transceiver units are deactivated for the rest of the time (eg put in an energy saving mode) can be used to save energy. This is particularly advantageous if the respective subscriber has only limited energy resources available, for example because the subscriber is battery-operated or draws energy from the environment by means of an energy harvesting element.

The participants 106_1-106_n of the communication system 100 can be, for example, actuator nodes and / or sensor nodes, such as heating meters, motion detectors, smoke detectors, etc.

Optionally, the base station 104 and the subscribers 106_1-106_n of the communication system 100 can be designed to transmit data based on the telegram splitting method. Here, the data to be transmitted, such as a telegram or data packet (e.g. the physical layer in the OSI model), e.g. an uplink data packet or a downlink data packet, are transferred to a plurality of sub-data packets (or partial data packets) on the data sender side ) and the sub-data packets are not transmitted coherently, but distributed in time and / or frequency according to a time and / or frequency hopping pattern, with the sub-data packets being reassembled (or combined) on the data receiver side in order to obtain the data packet . Each of the sub-data packets contains only part of the data packet. The data packet can also be coded (for example channel-coded or error-protection-coded) so that not all sub-data packets, but only some of the sub-data packets, are required for error-free decoding of the data packet.

The distribution of the plurality of sub-data packets in time and / or frequency can, as already mentioned, take place in accordance with a time and / or frequency hopping pattern.

A time jump pattern can specify a sequence of transmission times or transmission time intervals with which the sub-data packets are sent. For example, a first sub-data packet can be sent at a first transmission time (or in a first transmission time slot) and a second sub-data packet at a second transmission time (or in a second transmission time slot), the first transmission time and the second transmission time being different. The time jump pattern can define (or specify, or specify) the first transmission time and the second transmission time. Alternatively, the time jump pattern can indicate the first transmission time and a time interval between the first transmission time and the second transmission time. Of course, the time jump pattern can also only indicate the time interval between the first point in time and the second transmission point in time. There may be pauses in transmission between the sub-data packets in which no transmission takes place. The sub-data packets can also overlap (overlap) in time.

A frequency hopping pattern can specify a sequence of transmission frequencies or transmission frequency hops with which the sub-data packets are sent. For example, a first sub-data packet can be sent with a first transmission frequency (or in a first frequency channel) and a second sub-data packet with a second transmission frequency (or in a second frequency channel), the first transmission frequency and the second transmission frequency being different. The frequency hopping pattern can define (or specify, or specify) the first transmission frequency and the second transmission frequency. Alternatively, the frequency hopping pattern can indicate the first transmission frequency and a frequency spacing (transmission frequency hopping) between the first transmission frequency and the second transmission frequency. Of course, the frequency hopping pattern can also only specify the frequency spacing (transmission frequency hopping) between the first transmission frequency and the second transmission frequency. Of course, the majority of sub-data packets can also be transmitted both in terms of time and frequency. The distribution of the plurality of sub-data packets in terms of time and frequency can take place in accordance with a time and frequency hopping pattern. A time and frequency hopping pattern can be the combination of a time hopping pattern and a frequency hopping pattern, i.e. a sequence of transmission times or transmission time intervals with which the sub-data packets are transmitted, transmission frequencies (or transmission frequency hops) being assigned to the transmission times (or transmission time intervals).

A bandwidth of the occupancy of the frequency band indicated by the frequency hopping pattern can be significantly (e.g. at least a factor of 5 (or 10) larger than a bandwidth of the reception filters of the receivers (receivers or transceivers) of the participants 1Q6_1-106_n. To receive a telegram splitting -based

Data transmission, the respective subscriber can therefore be designed to switch the receiving frequency of his receiver based on the frequency hopping pattern (e.g. at the respective times or time slots specified by the time hopping pattern) to the respective frequencies or frequency channels of the frequency band specified by the frequency hopping pattern in order to switch the plurality of sub - Receive data packets.

FIG. 4 shows a schematic block diagram of the base station 104 and one of the subscribers 106_1-106_n of the communication system 100 shown in FIG. 3, according to an exemplary embodiment of the present invention.

The subscriber 106_1 can have a transmitter (or transmission module; transmitter) 108_1 which is designed to send the uplink data transmission 120 to the base station 104. The transmitter 108_1 can be connected to an antenna 110_1 of the subscriber 106_1. The subscriber 106_1 can furthermore have a receiver (or receiving module; receiver) 112_1 which is designed to receive the downlink data transmission 122 from the base station 104. The receiver 112_1 can be connected to the antenna 110_1 or a further antenna of the subscriber 106_1. The subscriber 106_1 can also have a combined transceiver (or transceiver module; transceiver).

The base station 104 can have a receiver (or receiving module; receiver) 114 which is designed to receive the uplink data transmission 120 from the subscriber 106_1. The receiver 114 may be connected to an antenna 116 of the base station 104. The base station 104 can also have a transmitter (or transmitter module; transmitter) 118 which is designed to send the downlink data transmission 122 to the subscriber 106_1. The transmitter 118 can be connected to the antenna 116 or a further antenna of the base station 104. The base station 104 can also have a combined transceiver (or transceiver module; transceiver).

The communication system 100 described with reference to FIGS. 3 and 4 can, for example, be an LPWAN (LPWAN = Low Power Wide Area Network), as is defined, for example, in the ETSI TS 103 357 [4] standard.

In the following, exemplary embodiments of a subscriber 106_1 and a base station 104 are described which can be used, for example, in the communication system 100 described above with reference to FIGS. 3 and 4. Of course, the exemplary embodiments of subscriber 106_1 and / or base station 104 described below can also be implemented or implemented in other communication systems with subscribers that do not transmit in a coordinated manner.

1 Signaling of a multicast message in non-coordinated networks

The exemplary embodiments described below make it possible to send a multicast message (point-to-multipoint-

Data transmission) from the base station 104 to the subscribers 106_1-106_n or a part (real subset) of the subscribers 106_1-106_n.

This could be implemented, for example, as shown in FIG. 5, wherein during the transmission of the multicast message (point-to-multipoint data transmission) 124 preferably no other data transmissions (e.g. overlapping / superimposing the point-to-multipoint data transmission 124) ( eg uplink data transmissions 120 and / or downlink data transmissions 122) take place.

In detail, FIG. 5 shows in a diagram an occupancy of a frequency band of the communication system 100 when carrying out several uplink data transmissions 120 and downlink data transmissions 122 between the base station 104 and several of the subscribers 106_1-106_n as well as a point-to-multipoint data transmission 124 of the

Base station 104 to several of the subscribers 106_1-106_n, according to an exemplary embodiment of the present invention. The ordinate in FIG. 5 describes the Frequency and the abscissa the time. In other words, FIG. 5 shows an example of a multicast message (point-to-multipoint data transmission) 124 in a non-coordinated communication system.

In order for such a multicast message (point-to-multipoint data transmission) 124 according to FIG _mu iticast the point-to-multipoint data transmission 124 or other information, based on which the subscribers 106_1-106_n can receive the point-to-multipoint data transmission 124, as will be explained below.

6 shows a schematic block diagram of a subscriber 106_1 and a base station 104, according to an exemplary embodiment of the present invention.

The subscriber 106_1 (e.g. end point) can be designed to send data in an uncoordinated manner with respect to the base station 104 and / or other subscribers of the communication system 100 (see FIG. 3).

The subscriber 106_1 can also be designed to send an uplink data transmission 120 to the base station 104, and to receive a downlink data transmission 122 from the base station 104 in a time-synchronized manner with the uplink data transmission 120, the downlink data transmission 122 being a Signaling information, the signaling information indicating a subsequent point-to-multipoint data transmission 124 of the base station 104 and / or a further data transmission preceding the point-to-multipoint data transmission 124 (e.g. a data transmission preparing the point-to-multipoint data transmission) or signaled.

The subscriber 106_1 can further be designed to receive the point-to-multipoint data transmission (e.g. multicast data transmission) 124 from the base station 104 based on the signaling information.

The base station 104 can be designed to receive the uplink data transmission 120 from the subscriber 106_1, and to send the downlink data transmission 122 to the subscriber 106__1 synchronized in time with the received uplink data transmission 120, the downlink data transmission 122 being the Having signaling information, the signaling information the subsequent point-to-multipoint Indicates or signals data transmission 124 of the base station 104 and / or the further data transmission preceding the point-to-multipoint data transmission 124 (for example data transmission preparing the point-to-multipoint data transmission).

The base station 104 can further be configured to send the point-to-multipoint data transmission 124 in accordance with the signaling information to the subscriber 160 (e.g. and to one or more other subscribers of the communication system 100).

In exemplary embodiments, the signaling information can include information about a point in time of the point-to-multipoint data transmission 124. For example, the information about the point in time can be an absolute point in time, a relative point in time (for example a defined time span between the downlink data transmission 122 and the point-to-multipoint data transmission 124) or information from which the absolute or relative point in time is derived can, such as a number of clock cycles of a clock generator (oscillator) of the subscriber.

In exemplary embodiments, the signaling information can additionally or alternatively include information about a frequency or a frequency channel (e.g. the frequency band used by the communication system) of the point-to-multipoint data transmission 124. For example, the information about the frequency can be an absolute frequency or a relative frequency (e.g. a distance between a frequency of the downlink data transmission 122 and a frequency of the point-to-multipoint data transmission 124). For example, the information about the frequency channel can be an absolute frequency channel or a relative frequency channel (e.g. a distance between a frequency channel of the downlink data transmission 120 and a frequency channel of the point-to-multipoint data transmission 124).

In exemplary embodiments, the point-to-multipoint data transmission 124 can have a plurality of sub-data packets which are transmitted in a time and / or frequency distributed according to a time and / or frequency hopping pattern (telegram splitting transmission method). In this case, the signaling information can also include information about the time and / or frequency hopping pattern of the point-to-multipoint data transmission 124. For example, the point-to-multipoint data transmission 124 can be a telegram splitting-based data transmission. In the case of data transmission based on telegram splitting, the data to be transmitted (for example (coded) user data of the physical layer) are split into a plurality of sub-data packets so that the plurality of sub-data packets each have only part of the data to be transmitted, the plurality of sub-data packets not being transmitted contiguously but rather distributed in time and / or frequency according to a time and / or frequency hopping pattern.

Detailed exemplary embodiments of the subscriber 106_1 and the base station 104 are described in more detail below.

1.1 Signaling in the previous downlink packet

Typically, in addition to messages intended for several subscribers 106_1-106_n, the base station 104 also transmits individual information to the subscribers 106_1-106_n, e.g. an authenticated confirmation or a change in parameters of the respective subscriber. Since these are individual for each participant, an individual downlink must be transmitted.

This is the point at which embodiments of the present invention come into play, in that the individually transmitted Downiink message (Downiink data transmission) 122 shows the transmission time of the following multicast message (point-to-multipoint data transmission).

124 is appended.

If several frequency channels are available, in addition to the signaling of the transmission time, information about the transmission channel can also be added (e.g. signaled).

As a result of this signaling, the point in time and possibly the frequency channel of the pending multicast message (point-to-multipoint data transmission) 124 is now known to a subscriber. Other participants can also be synchronized to the multicast message (point-to-multipoint data transmission) 124 with the aid of the same method.

If there are no data to be sent individually to the subscriber, in this case only the point in time and possibly the frequency channel in the pending Downiink message (Downiink data transmission) 124 can be transmitted.

This method has the advantage that only the participants (the plurality of participants 106_1-106_n of the communication system 100) from whom the multicast message (point-to-multipoint data transmission) 124 is to receive the time and if necessary, the frequency channel is communicated. Thus, for the subscribers who are not to receive the multicast message (point-to-multipoint data transmission) 124, there is no additional effort that increases battery consumption.

7 shows the sequence of the signaling of the multicast message (point-to-multipoint data transmission) 124 from the uplink message (uplink data transmission) 120 to the actual multicast message (point-to-multipoint data transmission) 124 by way of example for a subscriber in an uncoordinated radio network (communication system) 100.

In detail, FIG. 7 shows in a diagram an occupancy of the frequency band of the communication system 100 when performing an uplink data transmission 120, a downlink data transmission 122 and a point-to-multipoint data transmission 124, according to an exemplary embodiment of the present invention. In FIG. 7, the ordinate describes the frequency and the abscissa describes the time.

As can be seen in FIG. 7, the downlink data transmission 122 takes place in a time-synchronized manner with the uplink data transmission 120, for example after a predetermined (defined) time after the uplink data transmission 120. The downlink data transmission 122 has signaling information which indicates or signals the subsequent point-to-multipoint data transmission 124.

The signaling information can, for example, as indicated in FIG. 7, include information about a point in time of the point-to-multipoint data transmission 124. Of course, the signaling information can also additionally or alternatively contain information about a frequency or a frequency channel of the point-to-multipoint data transmission 124.

In embodiments, the signaling information, provided that the point-to-multipoint data transmission 124 is transmitted based on the telegram splitting transmission method (TSMA, Telegram Splitting Multiple Access), information about the time and / or frequency hopping pattern of the point-to-point Have multipoint data transmission 124.

In other words, if TSMA is used for the transmission of the multicast message (point-to-multipoint data transmission) 124, the hop pattern (time and / or frequency track pattern) can also be signaled if this has not been globally defined in advance. In exemplary embodiments, the information about the transmission time and / or transmission channel (transmission frequency) and / or the hop pattern (only with TSMA) can thus be appended to an individually generated downlink data packet (eg the downlink data transmission 120) to a subscriber.

In [4] a so-called authenticated wake-up and / or authentication message was defined in the downlink. With the aid of this message, the base station 104 can send a confirmation of the preceding uplink message individually to a subscriber. If there are further individual data for the subscriber, the length of this data and the distance between the message and the following data are also signaled in this message. If there is now a signaling of a multicast message to a subscriber and there are no further individual data for the subscriber, the additional transmission in addition to the wake-up and authentication message can only be used for the signaling of the multicast message.

In the case of pure signaling of a multicast message (point-to-multipoint data transmission) 124, the fields that contain the additional information for the following data (length and time information or PSI and TSI in [4]) can also be used for direct signaling of the multicast message (point-to-multipoint data transmission) 124 (time, frequency, length, etc.) can be used. This reduces the overhead that would be required for the separate transmission in addition to the wake-up and authentication messages.

In exemplary embodiments, available fields in a wake-up and / or authentication message (downlink data transmission according to [4]) can be used for this purpose in the case of pure signaling of a multicast message (point-to-multipoint data transmission).

1.2 Coarse time sianalization

It often takes a long time, according to section 1.1, until all the necessary subscribers have been informed of the preceding multicast message (point-to-multipoint data transmission) 124. A very large time difference must be signaled precisely for those participants who are informed very early about the pending multicast message (point-to-multipoint data transmission) 124. In order to be able to resolve these appropriately finely, a correspondingly large number of bits are required which are to be transmitted. For subscribers who (in terms of time) are very close to the actual multicast message (point-to-multipoint Data transmission) 124 are informed about this, the upper digits of the bits of the data field in the signaling are zero with the same resolution.

It follows that depending on the (time) difference between signaling and the

Multicast message (point-to-multipoint data transmission) 124 a sequence of different lengths for signaling would be useful.

However, if a real subscriber is considered who has a quartz, then it becomes apparent that the inaccuracy of the time when the subscriber expects the multicast message (point-to-multipoint data transmission) 124 is also dependent on the time difference between signaling and the Multicast message (point-to-multipoint data transmission) 124 is.

The longer this difference is, the less precise is the point in time which the subscriber assumes for the multicast message (point-to-multipoint data transmission) 124. The more imprecise this point in time, the larger the subscriber selects the search range for the multicast message (point-to-multipoint data transmission) 124. If the search range is significantly higher than the resolution of the transmitted point in time of the multicast message (point-to-multipoint Data transmission) 124, the lower resolution (and thus more uncertainty) can be selected without drastically increasing the search range (in the worst case the crystal error and the resolution error add up).

Typical values for an inaccuracy in the signaling range from 1 symbol (e.g. symbol duration) to 10,000 symbols (e.g. symbol duration).

Values higher than 10,000 symbols (e.g. symbol durations) have too great an inaccuracy and would require a very extensive post-synchronization.

It is important to note here that with ideal timing the uncertainty is still so great that reception would not be possible without post-synchronization.

In embodiments, the resolution of the signaling can have a certain inaccuracy, which can be determined in the context of the post-synchronization.

Instead of or in combination with the rough signaling of the point in time, a non-linear scaling of the point in time can also be selected, for example a logarithmic scaling. This has the advantage that points in time that are close to the pending multicast message (Point-to-multipoint data transmission) 124 lie, have a more precise resolution than points in time that are even further away. However, according to the above, this is not critical, since crystal offsets (e.g. frequency offsets of the crystals) increase the inaccuracies with increasing (temporal) distance to the multicast message (point-to-multipoint

Data transfer) 124 increase. Thus, the resolution can also become correspondingly more inaccurate, the further the time of the multicast message (point-to-multipoint data transmission) 124 lies in the future.

In exemplary embodiments, the resolution of the signaling can have a non-linear scaling.

1.3 Signaling of a further uplink message

Typically, for signaling the time of the multicast message (point-to-multipoint data transmission) 124 according to section 1.1 or section 1.2, a variable with, for example, 16 bits is transmitted. With an exemplary selected quantization of 1 s per LSB (Least Significant Bit), a maximum difference between the signaling and the multicast message (point-to-multipoint data transmission) 124 of 65536 seconds results. This equates to about 18 hours.

It should thus be ensured that all participants required for the multicast message (point-to-multipoint data transmission) 124 can be informed within 18 hours before the message.

In large networks with several hundred thousand subscribers (e.g. nodes) 106_1-106_n, this typically cannot be implemented, since there may be subscribers who transmit data to the base station 104 only once a day or even less frequently. Thus, with the parameters given above, it is not possible to notify or signal the pending multicast message (point-to-multipoint data transmission) 124 to all subscribers (e.g. nodes).

In exemplary embodiments, all subscribers to whom the multicast message (point-to-multipoint data transmission) 124 is notified in time before the maximum signaling length can, instead of the time of the multicast message (point-to-multipoint data transmission) 124, receive an (approximate ) Time are communicated at which the subscribers should / must send an uplink message (uplink data transmission) 120 to the base station 104 again. If this new uplink message (uplink data transmission) 120 is sent out by the subscriber, the base station 104 can send back a downlink message (downlink data transmission) 122 and in this then the time of the multicast message (point-to-multipoint Data transfer) 124.

The timing of this scheme is sketched in FIG. 8. In this case, a (rough) time for a further uplink message (second uplink data transmission) 120_2 was transmitted in the first downlink message (first downlink data transmission) 122_1. The second downlink message (second downlink data transmission) 122_2 was then followed by the message about the time and / or frequency for the multicast message (point-to-multipoint data transmission) 124.

In detail, Fig. 8 shows in a diagram an occupancy of the frequency band of the communication system 100 when performing a first uplink data transmission 120_1, a first downlink data transmission 122_1, a second uplink data transmission 120_1, a second downlink data transmission 122_2 and a point to multipoint data transmission 124, according to an embodiment of the present invention. In FIG. 8, the ordinate describes the frequency and the abscissa describes the time.

As can be seen in FIG. 8, the first downlink data transmission 122 takes place in a time-synchronized manner with the first uplink data transmission 120_1, e.g. after a predetermined (defined) time after the first uplink data transmission 120_1. The first downlink data transmission 122 has first signaling information.

The first signaling information can indicate or signal a further data transmission preceding the point-to-multipoint data transmission 124 (for example data transmission preparing the point-to-multipoint data transmission) Uplink data transmission 120_2 as well as the second downlink data transmission 122_2 that follows it in a time-synchronized manner.

As indicated in FIG. 8, the first signaling information can signal a time period or point in time (e.g. rough point in time) for the second uplink data transmission 120_2, the second uplink data transmission 122_2 taking place at the time period or rough point in time signaled with the first signaling information , and where the second downlink data transmission 122_2 is synchronized in time with the second uplink data transmission 120_2, for example after a predetermined (defined) time after the first uplink data transmission 120_1. The second downlink data transmission 122_2 may include a second signaling information _"in which the second signaling information to-multipoint data transmission point 124 indicative of the subsequent base station 104 or signaled.

The second piece of signaling information can, for example, _“ as indicated in FIG. 8, _” have information about a point in time of the point-to-multipoint data transmission 124. Of course, the second signaling information item can also additionally or alternatively contain information about a frequency or a frequency channel of the point-to-multipoint data transmission 124. Provided that the point-to-multipoint transmission method Telegram splitting (TSMA, Telegram splitting Multiple Access) is transmitted data transmission 124 based on _"the second signaling information is information about the time and / or frequency hopping pattern may also, additionally or alternatively, the point to multipoint data transmission 124.

In other words, _"Fig. 8 shows a signaling a time for a further uplink message (eg, second uplink transmission) 120_2, wherein the other uplink message (second example of uplink transmission) 120_2 another downlink message (for example, second downlink data transfer) 122_2 follow _"the example for a time to the multicast message (eg, point-to-multipoint data transmission defined) 124

Sends a participant even rarer messages to the base station 104 _"for example, only once a _week" it is possible more than once a further uplink message (uplink data transmission) to request _"until the necessary time is for signaling within the valid range.

In embodiments, instead of signaling the timing, the multicast message (point-to-multipoint data transmission), a (rough, approximate) time be defined _"to which the participant is to send another uplink message / needs.

The lack of coordination of the communication system (radio network) 100 can lead to disturbances and failures in the transmission. Often, the communication system described herein operates in the license-free bands 100 _'in which the communication system 100 divides the resources with other communication systems (see. Fig. 3) _»wherein the communication system 100 and other communications systems are not mutually coordinated. This can also lead to interference from external communication systems.

The telegram splitting transmission method has indeed developed a method that has a very high level of interference immunity, but here, too, a 100% probability of getting through cannot be guaranteed.

If a subscriber has been notified of a further transmission of an uplink message (LJplink data transmission) according to Section 1.3, the subscriber can expect a reliable response from the base station 104 in the downlink (e.g. in the form of a downlink data transmission).

However, if the subscriber does not receive any or only an incorrect / faulty / destroyed downlink message (downlink data transmission), the subscriber is aware that something went wrong during the transmission (e.g. due to a disturbance in the channel). In this case, the subscriber can promptly send a further uplink message (e.g. a third uplink data transmission) (e.g. a repetition of the previous uplink message (e.g. the second uplink data transmission 120_2)) to the base station 104. Then the downlink message (e.g. third downlink data transmission) from the base station 104 is waited for again. If this is now correctly received, it is ensured that the uplink message (e.g. third uplink data transmission) has now arrived correctly at the base station 104. Otherwise, the subscriber can open a further receive window (e.g. for a further downlink data transmission) (insofar as this is known to the base station 104) or carry out another transmission of an uplink message (uplink data transmission).

In exemplary embodiments, if the further uplink message (e.g. second uplink data transmission) signaled in time (e.g., second uplink data transmission), no correct response was received in the downlink (e.g. in the form of a second downlink data transmission), another uplink message (promptly) (e.g. third uplink data transmission).

Alternatively, for signaling the multicast message (point-to-multipoint data transmission) 124 may continue to the ^'time of the multicast message (point-to-multipoint data transmission) mitt divided 124 are, but with a different resolution (for example, 1 minute - > 1.5 months range). The subscriber can then decide for himself when (before the multicast message (point-to-multipoint data transmission) 124) he will again send an uplink message (e.g. fourth uplink data transmission) to the more precise point in time (the point-to-multipoint Data transfer 124). As a result, the subscriber can wait up to 1 hour before the multicast message (point-to-multipoint data transmission) 124 to see whether an uplink message (uplink data transmission) is necessary anyway and thus receives the exact point in time. If this is not the case, the subscriber can send a dedicated uplink message (eg fourth uplink data transmission). The dedicated uplink message (e.g. fourth uplink data transmission) should of course (pseudo) be placed randomly in the remaining time so that not all participants (e.g. nodes) who have not yet synchronized the time for the multicast message (point-to-point) Multipoint data transmission) 124 have to send at once.

In exemplary embodiments, the resolution in the signaling of the point in time can be selected to be greater for subscribers who are informed long before the actual multicast message. The subscriber can then first wait to see whether an uplink message (uplink data transmission) has occurred until shortly before the multicast message (point-to-multipoint data transmission) 124. If not, a dedicated uplink message (e.g. fourth uplink data transmission) can be triggered.

1.4 Signaling of the time and / or the friendship channel of a support beacon

In embodiments, a so-called support beacon can be used before the transmission of a multicast message (point-to-multipoint data transmission) 124. Such a support beacon can contain signaling up to the next support beacon or up to the multicast message (point-to-multipoint data transmission) 124.

In exemplary embodiments, the subscribers (of the communication system 100) can be synchronized to these support beacons. In the same way as in section 1.1, for example, the time to the support beacon and, if applicable, the frequency channel used can be signaled to the support beacon, as is shown schematically in FIG. 9.

9 shows in a diagram an occupancy of the frequency band of the communication system 100 when performing an uplink data transmission 120, a downlink data transmission 122 and a point-to-multipoint data transmission 124, according to an exemplary embodiment of the present invention. In FIG. 9, the ordinate describes the frequency and the abscissa describes the time.

As can be seen in FIG. 9, the downlink data transmission 122 takes place in a time-synchronized manner with the uplink data transmission 120, for example after a predetermined (defined) time after the Uplink data transmission 120. The downlink data transmission 122 has a first piece of signaling information.

The first signaling information can be one of the point-to-multipoint data transmission

124 indicate or signal preceding further data transmission (e.g. data transmission preparing the point-to-multipoint data transmission), with the further data transmission being a support beacon in the exemplary embodiment shown in FIG

123 is.

As indicated in FIG. 9, the first piece of signaling information can include information about a point in time of the support beam 123. Of course, the first signaling information item can also additionally or alternatively contain information about a frequency or a frequency channel of the support beacon. If the support beacon 123 is transmitted based on the telegram splitting transmission method (TSMA, Telegram Splitting Multiple Access), the first signaling information can additionally or alternatively include information about the time and / or frequency hopping pattern of the support beacon

124 have.

The support beacon can have a second piece of signaling information, the second signaling information indicating or signaling a further support beacon or the subsequent point-to-multipoint data transmission 124 of the base station 104.

The second piece of signaling information can, for example, as indicated in FIG. 9, include information about a point in time of the point-to-multipoint data transmission 124. Of course, the second signaling information can also additionally or alternatively contain information about a frequency or a frequency channel of the point-to-point

Have multipoint data transmission 124. If the point-to-multipoint data transmission 124 is transmitted based on the telegram splitting transmission method (TSMA, Telegram Splitting Multiple Access), the second signaling information can additionally or alternatively contain information about the time and / or frequency hopping pattern of the point to multipoint data transmission 124.

In other words, FIG. 9 shows a signaling of the time and possibly the frequency offset from a message from a subscriber (downlink data transmission 120) to a support beacon 123. In embodiments, the information about the transmission time and / or transmission channel (transmission frequency) and / or jump pattern (only with TSMA) can be attached to a support beacon to an individually generated downlink data packet (eg a downlink data transmission 120) to a subscriber.

1.5 Compensation of quartz offsets

As already mentioned in section 1.2, both the subscribers 106_1-106_n and the base station 104 usually have oscillating crystals (e.g. as a clock generator) for generating internal reference frequencies. However, these crystals are not ideal and have so-called tolerances on the frequencies provided. These tolerances are also transferred to the internal reference frequencies.

From these reference frequencies, among other things, the transmission frequency and the timer, which determine the time differences between the messages, are fed. Thus, the tolerances of the quartz have a direct effect on the transmission and also the reception of messages.

In [4], for example, the receiving frequency of a subscriber is estimated from the uplink message (uplink data transmission) and the transmission frequency in the downlink is modified accordingly so that the subscriber can receive the downlink message (downlink data transmission) without a frequency offset. In other words, the properties of the downlink message (downlink data transmission) are adapted according to the frequency offset (of the crystal) of the subscriber so that the subscriber no longer sees the frequency offset of the crystal.

This scheme works properly as long as there is only communication between a base station 104 and a subscriber 106_1. If a base station 100 communicates with two or more subscribers 106_1-106_n, the base station 104 receives a different frequency offset for each of the subscribers 108_1-106_n, which was generated by the respective crystal.

This means that it is not possible to send a multicast message (point-to-multipoint data transmission) 124 to all subscribers 106_1-106_n in such a way that all subscribers 106_1-106_n have no or a negligibly small frequency offset and / or time offset (time offset) due to their See quartz. Each participant (eg node) has to perform a time and frequency synchronization at the beginning of the multicast message (point-to-multipoint data transmission) 124 due to its permissible tolerances.

Based on a typical quartz oscillator with a tolerance range of 20 ppm and the maximum signaling length of approx. 18 h shown as an example in Section 1.3, there is a maximum temporal inaccuracy of the subscriber at the time of the transmission of the multicast message (point-to-multipoint data transmission) 124 from 65536 s * 20 ppm = 1.31 s. The subscriber must therefore search a search area of ± 1.31 s before and after the assumed point in time of the multicast message (point-to-multipoint data transmission) 124 for the correct point in time.

The same applies to the frequency offset; with a typical carrier frequency of 900 MHz, the maximum offset is ± 18 kHz, which must be searched for by the respective subscriber.

If the participant has correspondingly fast processors for a real-time search, it can determine the correct time and the frequency offset without large memory requirements. However, if the search cannot be carried out in real-time, all baseband data can alternatively be stored for a subsequent offline evaluation.

In the second case, the participants typically only have very small microprocessors on which a complete storage of the baseband data with such great inaccuracies is not possible.

Consider the following example: The data rate of the multicast message (point-to-multipoint data transmission) 124 is 5 kHz. With the 20 ppm crystal offset mentioned above, the bandwidth to be searched is therefore at least 2 * 18 kHz + 5 kHz = 41 kHz. This means that the sampling rate when using an SDR front end in the baseband (I phase and Q phase) is also at least 41 kSamples / s. In the above-mentioned search range of ± 1.31 s, it must therefore be possible to temporarily store 107,420 samples in the memory for processing. With a typical ADC resolution of 16 bit (16 bit I phase and 16 bit Q phase) this requires a working memory of at least 429.680 kB. Typical values for main memory on small microprocessors are less than 100 kByte (eg 64 kByte). This means that offline processing of the entire search area cannot take place. In both cases, a very high computational effort is also required and thus the power consumption is also significantly increased, which is particularly critical for battery-operated participants.

It is therefore important to avoid large search areas in both time and frequency directions.

In some systems the participants also have more than one crystal, such as an IF crystal (LF = low frequency) and an HF crystal (HF = high frequency, German high frequency). The LF quartz generally requires less power than the HF quartz. Therefore, the LF quartz is usually operated continuously and the timing is derived from it. However, the radio chip requires a higher clock rate and is therefore operated with the HF quartz. The transmission frequency therefore depends on the HF crystal. The HF quartz can be switched off between transmissions for power reasons.

The LF quartz typically has a higher tolerance than the HF quartz. For example, the LF quartz can have a tolerance of e.g. 100 ppm, whereas the HF quartz can have a tolerance of e.g. 20 ppm.

As already mentioned, a measurement / estimation of the carrier frequency is carried out in [4]. From this, the frequency offset and, from this, the crystal error can be determined with the aid of the expected carrier frequency. Alternatively or in combination with the estimation of the carrier frequency, it would also be possible to measure the time intervals (between two telegrams / packets / transmissions or within a transmission with telegram splitting) in order to estimate the deviation of the crystal.

This offset or these offsets can also be transmitted in the downlink (i.e. with the downlink data transmission) together with the parameters from the previous sections 1.1 to 1.4. As a result, the subscriber now knows his crystal offset at the time the uplink message was sent (uplink data transmission).

Alternatively, the mean crystal offset from several previous uplink messages (uplink data transmissions) can also be used and / or, if the temperature is available, the temperature dependency can be included (report temperature-normalized frequency deviation).

If the method of determining the crystal offset by means of the time offset is used, the accumulated offset (e.g. time offset) can also be determined. Here, the base station 104 is the Time between any two transmissions (eg uplink data transmissions) (ie not necessarily two consecutive transmissions) known. The base station 104 now receives the two transmissions (for example uplink data transmissions) and determines the time difference between the transmissions (for example uplink data transmissions). The accumulated crystal offset (eg time offset) can be determined from this. The deviations of the quartz due to temperature fluctuations during the time between the two transmissions (e.g. uplink data transmissions) is thus accumulated, since the quartz must run continuously to determine the transmission times and the current ambient conditions always have an influence on the quartz.

The situation is different if the crystal offset is determined by the transmission frequency, since only the offset (e.g. frequency offset) at the current transmission time has an influence on the transmission frequency.

Typically, environmental conditions at the respective subscriber do not change suddenly, so that it can be assumed that if the current crystal offset (e.g. frequency offset of the crystal) is known, the maximum error over the time between signaling the multicast message (point-to-point) Multipoint data transmission) 124 and the actual transmission (the point-to-multipoint data transmission 124) is smaller than the maximum permissible crystal offset.

This reduces the search range both in time and in frequency direction, which saves computing power, storage space and thus also energy. If the same parameters are selected as in the previous example, except that in this case the crystal offset in the respective subscriber was corrected on the basis of the value from the previous uplink message (uplink data transmission), the maximum possible residual offset (e.g. residual frequency offset) is reduced to for example 5 ppm.

The maximum search range in the time direction is thus reduced to 328 ms or in the frequency direction to 4.5 kHz. This means that only a quarter of the storage space is required and the computing power is also reduced by this factor.

If more than one crystal is installed in the respective subscriber, the base station 104 can also determine the offset (for example frequency offset) for several crystals accordingly and signal this (for example in the downlink data transmission). Alternatively, the quartz crystals can also be coupled in the subscriber (e.g. node). This ensures that the (e.g. all) crystals (of the respective participant) have the same offset (e.g. frequency offset) own. In this case it is sufficient if the base station 104 only estimates the offset (for example frequency offset) of one crystal, since the respective subscriber can apply the offset directly to the other crystals.

In exemplary embodiments, the subscriber's quartz offset can be determined from the uplink message (uplink data transmission) and communicated to the subscriber in the following downlink message (downlink data transmission). The subscriber can correct this offset and select correspondingly smaller search windows when receiving the multicast message (point-to-multipoint data transmission).

As an alternative to signaling the crystal offset (e.g. frequency offset of the crystal) from the uplink (e.g. the uplink data transmission), the base station 104 can also use the crystal offset to adapt the signaled point in time of the multicast message (point-to-multipoint data transmission). For this purpose, the base station 104 can calculate the deviation of the point in time, taking into account the subscriber's quartz offset (e.g. end point) and signal the “wrong” or corrected point in time accordingly. The same applies to the signaling of the frequency channel and possibly the jump pattern in the case of telegram splitting.

The subscriber does not need to know anything about his crystal offset and can assume a lower crystal error (see above) when searching for the start of the multicast message (point-to-multipoint data transmission).

In exemplary embodiments, the crystal offset (e.g. frequency offset of the crystal) of the subscriber can be taken into account in the signaling of the start time (e.g. the point-to-multipoint data transmission 124) and modified accordingly in the base station 104.

2. Support beacon

The exemplary embodiments described below deal with multicast / broadcast transmissions (point-to-multipoint data transmissions to a real subset or to all participants) in radio systems with non-coordinated participants. In particular, exemplary embodiments for synchronizing and / or keeping the subscribers in sync in advance of a multicast ZBroadcast transmission are described. Based on the exemplary embodiments described in Section 1, greater time synchronization uncertainty arises in the case of larger time offsets between a participant's synchronization (signaling of the multicast / broadcast message) and the multicast / broadcast transmission. However, it may be desirable to synchronize subscribers over a long period of time in order, for example, to also reach subscribers with a low transmission frequency with the multicast / broadcast transmission.

This problem can be solved by using support beacons. The synchronization to a support beacon is already described in section 1. The following exemplary embodiments relate to designs of the support beacons.

FIG. 10 shows a schematic block diagram of a subscriber 106_1 and a base station 104 according to an exemplary embodiment of the present invention.

The subscriber 106_1 (e.g. end point) can be designed to send data in an uncoordinated manner with respect to the base station 104 and / or other subscribers of the communication system 100 (cf. FIG. 3).

The subscriber 106_1 can also be designed to receive one support beacon 123_1 or several (e.g. at least two) support beacons 123_1-123_4 of a plurality of support beacons 123_1-123_m of the base station 104, the one support beacon 123_1 or the several support beacons 123_1-123_4 providing synchronization information and to receive a point-to-multipoint data transmission 124 from the base station 104 based on the synchronization information.

The base station 104 can be designed to send out a support beacon 123_1 or a plurality of support beacons 123_1-123_m, the one support beacon 123_1 or the plurality of support beacons 123_1-123_m having synchronization information for the synchronization of uncoordinated transmitting subscribers of the communication system 100, the base station 104 is configured to send the point-to-multipoint data transmission 124.

In exemplary embodiments, the subscriber 106_1 can be designed to receive (precisely) one support beacon 123_1 from the base station 104, and to receive the point-to-multipoint data transmission 124 from the base station 104 based on the synchronization information contained in the support beacon 123_1. For example, the synchronization information of the support beacon 123_1 can include information about a point in time (for example, absolute or relative point in time, such as a time interval in relation to the support beacon 123_1)) of the point-to-multipoint data transmission 124.

Furthermore (or alternatively) the synchronization information of the support beacon 123_1 can comprise information about a frequency channel (e.g. absolute or relative frequency channel, such as a frequency channel spacing in relation to a frequency channel of the support beacon 123_1)) of the point-to-multipoint data transmission 124. Furthermore (or alternatively) the synchronization information of the support beacon 123_1 can have information about a time and / or frequency hopping pattern based on which the point-to-multipoint data transmission is transmitted. Based on the information about a point in time and / or frequency channel and / or jump pattern of the point-to-multipoint data transmission 124 (e.g. in relation to or relative to the support beacon 123_1), it is the subscriber 108_1 who is actually uncoordinated (and asynchronous) with respect to the base station 104 transmits, it is possible to receive the point-to-multipoint data transmission 124 of the base station 104.

For example, the synchronization information of the support beacon 123_1 can have a synchronization sequence for synchronizing the subscriber 106_1 to the support beacon 123_1, wherein the subscriber 106_1 can be designed to synchronize with the respective support beacon based on the synchronization sequence. As a result, the subscriber 106_1 can know, for example, a (relative) point in time and / or a (relative) frequency channel or a (relative) frequency of the support beacon 123_1. Based on the (relative) point in time and / or the (relative) frequency channel or the (relative) frequency of the support beacon 123_1 and information about a point in time and / or frequency channel and / or jump pattern of the point-to-multipoint data transmission 124 (e.g. in relation to or relative to the support beacon 123_1), which can be contained, for example, in the synchronization information of the support beacon 123_1 or which can be derived from information transmitted with the support beacon 123_1 or which is otherwise known to the subscriber 106_1 (e.g. from a previous downlink Data transmission 122), the subscriber 106_1, who is actually transmitting in an uncoordinated (and asynchronous) manner with respect to the base station 104, is able to receive the point-to-multipoint data transmission 124 from the base station 104.

In exemplary embodiments, the subscriber 106_1 can be designed to receive several (for example at least two) support beacons 123_1-123_4 from the base station 104 and, based on the synchronization information contained in the support beacons 123_1-123_4, the point-to-multipoint data transmission 124 of the Base station 104 to receive. In the exemplary embodiment shown in FIG. 10, it is assumed by way of example that five support beacons 123_1-123_m (m = 5) are transmitted by the base station 104. Furthermore, it is assumed in FIG. 10 by way of example that the support beacon 123_1 is transmitted before the point-to-multipoint data transmission 124 (for example that the support beacon 123_1 is the last support beacon transmitted before the point-to-multipoint data transmission 124), during the other support beacons are sent out at different times 123_2-123_5 before the support beacon 123_1.

The subscriber 106_1 can be designed to receive several (eg at least two) of the support beacons 123_1-123_m transmitted by the base station 104, ie at least a part (real subset) of the support beacons 123_1-123_m transmitted by the base station 104, such as the support beacons 123_1-123_4.

In exemplary embodiments, the support beacons 123_1-123_m can each have synchronization information. The synchronization information of the support beacons 123_1-123_m can thereby be ^identical or different.

In embodiments, the synchronization information can be information about

a point in time (e.g. an absolute or relative point in time, such as a time interval in relation to the respective support beacon)) of the transmission of a further support beacon and / or the point-to-multipoint data transmission 124, and / or

- a frequency channel (e.g. an absolute or relative frequency channel, such as a frequency channel spacing in relation to a frequency channel of the respective support beacon)) of the transmission of a further support beacon and / or the point-to-multipoint data transmission, and / or

- have a time and / or frequency hopping pattern based on which a further support beacon and / or the point-to-multipoint data transmission is transmitted.

For example, the synchronization information of one of the support beacons 123_2 to 123_5 (e.g. the support beacon 123_3), with the exception of the last support beacon 123_1, information about a point in time (e.g. an absolute or relative point in time, such as a time interval in relation to the respective support beacon)) Transmission of a further support beacon (for example the support beacon 123_2) or information about the points in time of the transmission of several further support beacons (for example the support beacons 123_2 and 123_1). Additionally or alternatively, the synchronization information of one or more of the support beacons 123_2 to 123J5 (for example the support beacon 123_3), with the exception of the last support beacon 123_1, can match information Point in time (for example absolute or relative point in time, such as a time interval in relation to the respective support beacon)) of the transmission of the point-to-multipoint data transmission 124. The synchronization information of the last support beacon 123_1 can include information about a point in time (eg absolute or relative point in time, such as a time interval in relation to the support beacon)) of the transmission of the point-to-multipoint data transmission 124.

For example, the synchronization information of one of the support beacons 123_2 to 123_5 (e.g. the support beacon 123_3), with the exception of the last support beacon 123_1, can contain information about a frequency channel (e.g. an absolute or relative frequency channel, such as a frequency channel spacing in relation to a frequency channel of the respective support beacon) ) the transmission of a further support beacon (eg the support beacon 123_2) or several further support beacons (eg the support beacon 123J2 and 123_1). Additionally or alternatively, the synchronization information of one or more of the support beacons 123_2 to 123_5 (e.g. the support beacon 123_3), with the exception of the last support beacon 123_1, can contain information about a frequency channel (e.g. an absolute or relative frequency channel, such as a frequency channel spacing in relation to a frequency channel the respective support beacon)) initiate the transmission of the point-to-multipoint data transmission 124. The synchronization information of the last support beacon 123_1 can include information about a frequency channel (e.g. absolute or relative frequency channel, such as a frequency channel spacing in relation to a frequency channel of the support beacon)) of the transmission of the point-to-multipoint data transmission 124.

For example, the synchronization information of one of the support beacons 123J2 to 123_5 (e.g. the support beacon 123_3), with the exception of the last support beacon 123_1, can be information about a time and / or frequency hopping pattern based on the one or more additional support beacons (e.g. the support beacons 123_2 and 123_1 ) are transmitted. Additionally or alternatively, the synchronization information of one or more of the support beacons 123_2 to 123_5 (e.g. the support beacon 123_3), with the exception of the last support beacon 123_1, can be information about a time and / or frequency hopping pattern based on the point-to-multipoint data transmission 124 is transmitted. The synchronization information of the last support beacon 123_1 can include information about a time and / or frequency hopping pattern based on which the point-to-multipoint data transmission 124 is transmitted.

Based on the signaling information contained in one or more support beacons (for example in support beacon 123_3 or in support beacon 123_4 and 123_3), it is up to the subscriber 106_1, which actually transmits in an uncoordinated (and asynchronous) manner with respect to the base station 104, thus making it possible to receive one or more additional support beacons (e.g. the support beacons 123_2 and 123_1) and ultimately the point-to-multipoint data transmission 124 from the base station 104.

In exemplary embodiments, the synchronization information (for example, in addition or as an alternative to the above exemplary embodiment) can have a synchronization sequence for synchronizing the subscriber 106_1 to the respective support beacon (eg to the support beacon 123_3) to synchronize the respective support beacon (e.g. support beacon 123J3). For example, a (relative) point in time and / or a (relative) frequency channel or a (relative) frequency of the respective support beacon (e.g. support beacon 123_3) can be known to subscriber 106_1 as a result of the synchronization. Based on the (relative) point in time and / or the (relative) frequency channel or the (relative) frequency of the respective support beacon (e.g. support beacon 123_3) and information about a point in time and / or frequency channel and / or jump pattern of one or more additional support beacons (e.g. the support beacons 123_2 and 123_1), which can be contained in the synchronization information of the respective support beacon (e.g. the support beacon 123_3) or which can be derived from information transmitted with the respective support beacon (e.g. the support beacon 123_3) or which can be derived from the subscriber 106_1 is otherwise known (e.g. from a previous Downiink data transmission 122), and information about a point in time and / or frequency channel and / or jump pattern of the point-to-multipoint data transmission 124, which is, for example, in the synchronization information of the respective support beacon (e.g. the support beacon 123_3) or further support beacons (e.g. support beacon 123_1) can be included or the v on one with the respective support beacon (e.g. the support beacon 123_3) or a further support beacon (e.g., the support beacon 123_1) can be derived from the information transmitted or which is otherwise known to the subscriber 106__1 (e.g. from a previous Downiink data transmission 122), it is the subscriber 106_1 who is actually uncoordinated (and asynchronous) with respect to the base station 104, it is possible to receive the point-to-multipoint data transmission 124 of the base station 104.

In exemplary embodiments, the support beacons 123_1-123_5 can be transmitted at regular intervals or on average at regular intervals, with the subscriber 106_1 knowing the intervals between the transmissions of the support beacons 123_1-123_5, for example from a previous downlink transmission 122 or an already received support beacon . In exemplary embodiments, the support beacons 123_1-123_5 can be transmitted at predetermined times and / or with predetermined time intervals and / or in predetermined frequency channels and / or in predetermined frequency channel intervals and / or in accordance with a predetermined time hopping pattern and / or in accordance with a predetermined frequency hopping pattern, whereby the subscriber 106_1 can be designed to receive the support beacons based on the predetermined times and / or the predetermined time intervals and / or the predetermined frequency channels and / or the predetermined frequency channel intervals and / or the predetermined time hopping pattern and / or the predetermined frequency hopping pattern.

In embodiments, one or more (eg all) of the support beacons 123_2-123-5, with the exception of the last support beacon 123_1, (eg each) have information about the transmission of a (eg each) subsequent support beacon, whereby the subscriber 106_1 can be configured in order to receive the subsequent support beacon (for example, in each case) based on the information about the transmission of the subsequent support beacon (in each case, for example).

For example, the support beacon 123_3 can have information about the transmission of the support beacon 123_2, wherein the subscriber 106_1 can be configured to receive the support beacon 123_3 and to receive the support beacon 123_2 based on the information contained in the support beacon 123_3 about the support beacon 123_2.

For example, the information about the transmission of the (e.g. each) subsequent support beacon can be a point in time and / or time interval and / or a frequency channel and / or frequency channel interval and / or time hopping pattern and / or frequency hopping pattern.

For example, the information about the transmission of the (e.g. each) subsequent support beacon can be contained in the synchronization information of the respective support beacon.

In exemplary embodiments, a point in time and / or a frequency channel of the transmission of one or more (e.g. each) of the support beacons 123_1-123_4, with the exception of the first support beacon 123_5, can be derived from information transmitted with a preceding support beacon (e.g. CRC or support beacon counter), with the subscriber 106_1 can be designed to derive the time and / or frequency channel of the transmission of the respective support beacon from the information transmitted with the respective preceding support beacon in order to receive the respective support beacon. In embodiments, points in time and / or frequency channels, or a time hop pattern and / or frequency hop pattern of the transmission of the support beacons 123_1 - 123_5 based on a calculation rule, such as a polynomial of an LFSR (linear feedback shift register) or a PRBS ( Pseudorandom Bit Sequence, dt. Pseudo-random bit sequence) generator, where at least one of the support beacons (e.g. in the respective synchronization information) or the downlink data transmission 122 for the subscriber 106_1 has information about a current status of the calculation rule, whereby the subscriber 106_1 is designed to determine the times and / or frequency channels and / or the time hop pattern and / or frequency hop pattern of the transmission of the support beacons based on the calculation rule and the current state of the calculation rule in order to receive the support beacons. If the information (about the current status of the calculation rule) is contained in a support beacon or is transmitted with a support beacon, then this information can be contained, for example, in the first support beacon that a new subscriber to be synchronized receives, or in other words, The base station 104 can be designed to provide the support beacon currently to be sent out with this information at least when a new subscriber has been synchronized since the previous or previous transmission of a support beacon, for example by means of a downlink data transmission. This makes sense, for example, if a large number of newly synchronized subscribers are added per support beacon in order to send this additional information, for example, only once for all new subscribers.

In exemplary embodiments, signaling information can be used which is sent with a downlink data transmission 122 from the base station 104 to the subscriber 106_1 so that the subscriber 106_1 di0 can receive a support beacon 123_1 or the plurality of support beacons 123_1-123_m.

In detail, the subscriber 106_1 can be designed to receive a downlink data transmission 122 from the base station 104 in a time-synchronized manner with a sent uplink data transmission 120, the downlink data transmission 122 being a

Having signaling information, the signaling information signaling the transmission of the support beacon 123_1 or at least one of the plurality of support beacons 123_1-123_m.

The participant 106_1 can be designed to support the one support beacon 123_1 or at least one of the multiple support beacons 123_1-123_m based on the

Receive signaling information. For example, the signaling information can correspond to the signaling information from section 1, the signaling information signaling the one supporting beacon 123_1 or at least one of the several supporting beacons 123_1-123_m instead of the point-to-multipoint data transmission 124. Thus, the signaling information can be information about a time of the transmission of the one support beacon 123_1 or at least one of the several support beacons 123_1-123_m, and / or a frequency channel of the transmission of the one support beacon 123_1 or at least one of the several support beacons 23_1-123_m, and / or a Time and / or frequency hopping patterns based on which the one support beacon 123_1 or at least one of the plurality of support beacons 123_1-123_m are transmitted.

For example, the information about the point in time can be an absolute point in time, a relative point in time (for example a defined time span between the downlink data transmission 122 and the support beacon) or information from which the absolute or relative point in time can be derived, such as a number of Clock cycles of an oscillator of the subscriber 106_1.

For example, the information about the frequency channel can be an absolute frequency channel or a relative frequency channel (e.g. a distance between a frequency channel of the downlink data transmission 122 and a frequency channel of the support beacon).

For example, the support beacons can be transmitted based on the telegram splitting transmission method. When transmitting the support beacons based on the telegram splitting transmission method, data to be transmitted with the respective support beacon, such as a (coded) support beacon data packet of the physical layer, can be divided into a plurality of sub-data packets so that the plurality of sub-data packets respectively aulweisen only part of the data to be transmitted, wherein the plurality of sub-data packets are not transmitted contiguously distributed, but in the time and / or frequency corresponding to a time and / or frequency hopping pattern ^'.

In the following, detailed exemplary embodiments of the subscriber 106_1 and the base station 104 are described in more detail.

2.1 Support beacons to maintain synchronization As shown in section 1, it is necessary for a multicast transmission (point-to-multipoint data transmission) 124 to synchronize the subscribers 106_1-106_n (cf. FIG. 3) to the time of the transmission. However, due to tolerances in the clock generators (of the participants), this synchronization is limited in time, or the time error increases with a longer distance to the synchronization time. If the time error becomes too large, it is no longer practicable for a participant to receive the transmission because the search window would have to be selected too large. ·· Particularly in the case of subscribers 106_1-106_n with receivers that do not allow real-time processing of the received signals, the available buffer memory represents a limit to the size of the search window. This means that post-synchronization is required at regular intervals in order to keep the time error within a tolerable range. In particular with a high number of subscribers 106_1-106_n, it is advantageous to implement the resynchronization not by individual transmissions to the individual subscribers, but by a common beacon for all or at least some of the subscribers 106_1-106_n of the communication system 100.

In exemplary embodiments, the base station 104 can transmit a support beacon 123_1-123_5 for this purpose with sufficient frequency, which can be received by the synchronized subscribers 106_1-106_n. The subscribers 106_1-106_n thus receive a new synchronization time and the accumulated time error is limited. 11 shows a schematic representation of the support beacon concept.

In detail, Fig. 11 shows in a diagram an occupancy of the frequency band of the communication system 100 in a point-to-multipoint data transmission 124 and a transmission of several support beacons 123_1-123_m in advance of the point-to-multipoint data transmission 124, according to an embodiment of the present invention. In FIG. 11, the ordinate describes the frequency and the abscissa describes the time.

In FIG. 11, an uplink data transmission 120 and a downlink data transmission 122 synchronized in time with the uplink data transmission 120 can also be seen. Based on the downlink data transmission 122, which can include signaling information, such as information about a time and / or frequency channel of the transmission of the support beacon 123_4, the subscriber 106_1 can be synchronized, and the subscriber can be synchronized based on the support beacons 106 1 to be maintained. In other words, FIG. 11 shows several support beacon transmissions 123_1-123_m and a synchronization of a subscriber 106_1.

In exemplary embodiments, a point in time and / or a frequency and / or a jump pattern of the respective next support beacon (e.g. support beacon 123_3) can be derived from defined values or calculation rules for communication system 100 or the specific

Multicast transmission (point-to-multipoint data transmission) 124 result. In the case of multicast-specific values or rules, these can be transmitted during the first synchronization (e.g. using a unicast downlink (downlink data transmission 122). Alternatively, the information can also be transmitted with preceding support beacons (e.g. support beacon 123_4) the communication system 100 can be configured statically (for example frequency / hopping pattern) and others are transmitted in the support beacon (for example time interval).

In exemplary embodiments, the support beacons 123_1-123_m can be transmitted regularly in order to keep participants synchronized over a longer period of time.

In embodiments, for the transmissions of the support beacons 123_1-123_m for the communication system and / or this multicast transmission (point-to-multipoint

Data transmission) 124 fixed intervals and / or frequencies and / or hopping patterns can be used.

In exemplary embodiments, the time / interval and / or frequency and / or jump pattern can be transmitted from subsequent support beacons in the preceding support beacon.

In order to obtain a pseudo-random component in terms of time and / or frequency and / or hopping pattern, these values can also be derived from the data of the transmissions of the support beacons, e.g. using a CRC or a support beacon counter.

In exemplary embodiments, the distance and / or frequency and / or hopping pattern can be derived from a previous support beacon transmission, e.g. by CRC or support beacon counter.

A transmission of the time interval with the support beacons 123_1-123_m allows a dynamic adaptation of the intervals to the synchronized participants 106_1-106_n. If, for example, participants 106_1-106_n are synchronized with less precise timers, so the distances between the support beacons 123_1-123_m can be reduced in order to be able to guarantee a maximum time error at the time of reception for these subscribers 106_1-106_n as well.

In exemplary embodiments, the spacing of the support beacons 123_1-123_m can be dynamically adapted to the synchronization requirements of the currently psychronized subscribers 106_1-106_n.

Subscribers 106_1-106_n with a lower crystal error can also omit transmissions from support beacons 123_1-123_m and, for example, only receive every second or third support beacon. For this it is necessary that the distances are known in advance, at least for the number of support beacons to be skipped. This can be achieved with variable parameters by either transmitting several distances (frequencies, hopping patterns, etc.) in each support beacon 123_1-123_m or by using a calculation rule that allows the information for several support beacons to be determined in advance. For example, a polynomial in the form of an LFSR (Linear Feedback Shift Register) comparable to a CRC or PRBS (Pseudo Random Bit Sequence) generator can be used. With this polynomial and the current state, participants can calculate the states for future support beacons and derive the transmission parameters, such as time and / or distance and / or frequency and / or jump pattern.

In exemplary embodiments, subscribers 106_1-106_n with a less frequent need for resynchronization can skip transmissions from support beacons 123_1-123_m (not every support beacon received).

In exemplary embodiments, calculation rules for the distances and / or frequencies and / or jump patterns of the support beacons can be used in order to be able to determine them in advance for a plurality of support beacons.

If the parameters for several support beacons can be determined in advance, there is also the possibility for subscribers to try to receive the following support beacons again (possibly with increased search effort) if they fail to receive a transmission from a support beacon (e.g. due to channel interference). Only if this fails is a unicast uplink request (request by means of an uplink data transmission 120) necessary in order to receive a new synchronization by a unicast downlink (a downlink data transmission 122) from the base station 104. In exemplary embodiments, a subscriber can request unicast synchronization again if synchronization is lost (eg support beacon is no longer received).

In exemplary embodiments, if a support beacon is lost, a subscriber can attempt to synchronize himself again with subsequent support beacons before a new request is made to the base station 104.

2.2 Muiticast data transmission in support beacons

In exemplary embodiments, it is also possible to transmit the useful data of the multicast transmission (point-to-multipoint data transmission 124) distributed over the support beacons, as shown in FIG. 12.

In detail, FIG. 12 shows an occupancy of a frequency band of the communication system 100 during the transmission of a point-to-multipoint data transmission and a transmission of several support beacons 123_1-123_m, with useful data of the point-to-multipoint data transmission 124 being divided into a plurality of useful data parts 125_1-125_3 are divided and are each transmitted together with one of the support beacons 123_1-123_m, according to an embodiment of the present invention. In FIG. 12, the ordinate describes the frequency and the abscissa describes the time.

In other words, FIG. 12 shows a transmission of useful data parts 125_1-125_3 of the multicast transmission (point-to-multipoint data transmission) 124 with the support beacons 123_1-123_m. As illustrated in FIG. 12, each support beacon carries part of the useful data of the multicast transmission (point-to-multipoint data transmission) 124. The subscribers 106_1-106_n can receive several support beacons (e.g. support beacons 123_1, 123_4 and 123_3) receive the entire payload. This has the advantage that, particularly in the case of extensive multicast user data (user data from point-to-multipoint data transmission), the base station 104 can distribute the necessary duty cycle over a longer period of time. For example, it may not be legally permissible to send the entire user data of the multicast transmission (point-to-multipoint data transmission) 124 in one transmission; the problem can be avoided if distributed over a day in, for example, several support beacons (e.g. ten support beacons). In addition, it is common that a certain transmission format is required (eg minimum length, complete jump pattern, etc.), this can result in unused capacities in the support beacons, which can be used for user data. In exemplary embodiments, the multicast user data (user data of the point-to-multipoint data transmission) can be divided into several parts and these parts can be transmitted within the framework of the support beacons.

The individual parts (of the useful data of the point-to-multipoint data transmission 124) can be repeated cyclically in order to give subscribers 106_1-106_n, who are synchronized at a later point in time, the opportunity to receive missed parts in the next cycle. Participants 106_1-106_n who have received all parts can stop receiving additional support beacons.

In exemplary embodiments, the useful data parts 125_1-125_3 are repeated cyclically (e.g. the point-to-multipoint data transmission 124) in order to enable all useful data parts 125_1-125_3 to be received at different entry times.

The support beacons can be viewed as a kind of virtual multicast channel to which subscribers are synchronized and exit again after all data (e.g. all useful data parts 125_1-125_3 of the point-to-multipoint data transmission 124) have been received. The base station 124 holds the information about which subscriber was synchronized at what point in time in order to be able to determine when all subscribers 106_1-106_n have received all data (e.g. all useful data parts 125_1-125_3 of the point-to-multipoint data transmission 124). It is also conceivable here to terminate the transmission with a multicast that contains all parts that at least one subscriber could not receive.

The proportion of user data in the support beacons can also be dynamically increased or decreased depending on the currently available duty cycle of the base station 104 minimal necessary support beacons without user data is sent in order to maintain synchronization. It is also conceivable to scale the proportion of user data with the number of subscribers 106_1-106_n that have already been synchronized. If more participants 106_1-106_n are synchronized, it makes sense to bring in more data, since these participants 106_1-106_n then have to receive fewer support beacons 123_1-123_m and therefore need synchronization less often (due to the time offsets). This reduces the power consumption for these subscribers 106_1-106-n. The power consumption is reduced in the system means. In exemplary embodiments, the useful data components in the transmissions of the support beacons are dynamically adapted to the load on the base station 104 and / or the radio channel and / or the number of subscribers 106_1-106_n synchronized in.

The user data of the multicast transmission (point-to-multipoint data transmission) 124 can also be provided with additional error protection, which allows the overall data to be reconstructed if one or more parts (e.g. useful data parts of the point-to-multipoint data transmission 124 ) were not received. In extreme cases, this can go so far that only a small proportion of the useful data is required (e.g. 1/10). The error protection therefore covers far more than expected transmission errors and thus prevents, for example, a subscriber who is only psychronized when a large part of the useful data has already been transmitted from receiving all of the useful data from the remaining transmissions.

Conversely, the base station 104 can specifically cancel the multicast transmission (point-to-multipoint data transmission) 124 long before the transmission of all parts if all subscribers 106_1-106_n already have a sufficient number of parts (e.g. user data parts of the point-to-multipoint data transmission) received in order to enable a reconstruction of the user data. Individual participants can stop receiving additional support beacons if the user data has been reconstructed from the received parts. The user data is thus extended with so much error protection that it is no longer the goal to send all parts of the error-protected user data to each participant.

Instead, the error protection buffer is used to enable dynamic entry and exit during the transmission, in which only any small portion of all user data actually has to be transmitted. Correspondingly, a considerable proportion of the error-protected useful data parts are usually never sent out, since these useful data parts are only available as a reserve if, for example, a subscriber cannot be synchronized until very late.

In exemplary embodiments, it can be planned to transmit only a small portion of useful data parts to the subscribers. The useful data or useful data parts of the multicast transmission (point-to-multipoint data transmission) 124 have a high level of error protection for reconstruction.

In exemplary embodiments, the transmission / reception of the multicast transmission (point-to-multipoint data transmission) 124 by the base station 104 can be aborted and / or a subscriber 106_1 occurs when sufficient information has been transmitted.

The advantage compared to a cyclical repetition is that if a user data part is lost (the point-to-multipoint data transmission 124) it is not necessary to wait for the repetition of the specific user data part, but simply any other additional user data part can be received in order to carry out the reconstruction ( For example, to enable the user data of the point-to-multipoint data transmission 124). For example, it is conceivable that the base station 104 initially sends out a sufficient number of useful data parts in order to enable a reconstruction of the useful data (the point-to-multipoint data transmission 124) even with the last subscriber synchronized in (who was able to receive the fewest parts). . The base station 104 can then send out a certain number of further useful data parts in the event that previous useful data parts could not be received successfully.

2.3. Multicast Schedulinq in support beacons

When using support beacons 123_1-123_, the time of the multicast transmission (point-to-multipoint data transmission) 124 does not have to be fixed at the beginning of synchronization. Instead, subscribers I06_1-106_n that have already been synchronized can be kept synchronized by the support beacons until it appears sensible to carry out the multicast transmission (point-to-multipoint data transmission) 124. For example, the base station 104 can wait until a sufficiently large proportion of the subscribers 106_1-106_n could be synchronized via unicast (e.g. a downlink data transmission 122 with signaling information synchronized with an uplink data transmission 120) or until network or duty cycle capacities are free . It is sufficient that the subscribers 106_1-106_n only know the information for the next support beacon to be received; before the start of the actual multicast transmission (point-to-multipoint data transmission) 124, this can then be signaled in a support beacon. If participants can skip support beacons, the signaling can take place with sufficient lead time to reach all participants 106_1-106_n.

In exemplary embodiments, a start time of the multicast transmission (point-to-multipoint data transmission) 124 after the start of synchronization can be selected dynamically on the basis of subscribers already reached and / or network load and / or duty cycle. The support beacons 123_1-123_m can also be used to allow a finely granular scheduling of the subscribers 106_1-106_n. For example, all participants 106_1-106_n can first be synchronized to the virtual multicast channel (= support beacons) in order to then divide them into different multicast groups with addressing information in the support beacons (see FIG. 13) or to sort out individual participants again if they are in the In the meantime, it has been found that no multicast transmission (point-to-multipoint data transmission) 124 to these subscribers is necessary.

In detail, Fig. 13 shows in a diagram an occupancy of the frequency band of the communication system during the transmission of three point-to-multipoint data transmissions 124_1-124_3 for three different groups of participants of the communication system 100 as well as a common transmission of support beacons 123_1-123_m for the three different groups of participants of the communication system 100, according to an embodiment of the present invention. In FIG. 13, the ordinate describes the frequency and the abscissa describes the time.

In other words, FIG. 13 shows a division of the synchronized subscribers into different multicast transmissions (point-to-multipoint data transmissions) 124_1-124-3.

For example, several multicast transmissions (point-to-multipoint data transmissions) 124_1-124_3 can use one (or more) common support beacons. The participants are kept synchronized until the user data is transmitted (e.g. transmission of the respective point-to-multipoint data transmission 124_1 -124_3) and divided into groups. Before the transmission of useful data (e.g. transmission of the respective point-to-multipoint data transmission 124_1-124_3), each group is then assigned a dedicated distance and / or frequency and / or hopping pattern for the transmission of useful data. Methods from Section 1, for example, can be used for this purpose.

In exemplary embodiments, the support beacons 123_1-123_m are used for (e.g. for the transmission of) addressing information, via synchronized participants to individual

Multicasts transmissions (point-to-multipoint data transmissions) 124_1 -124J3 to be divided and / or sorted out again.

It is also possible to send the multicast transmission (point-to-multipoint data transmission) to a group of participants ahead of time and to keep the remaining participants in sync with support beacons. For example, multicast transmission (point-to-point Multipoint data transfer) for a group can be completed as soon as all participants in this group are synchronized while another group is still waiting for participants. This can also be advantageous if, due to network load or duty cycle, it is not possible to carry out all multicast transmissions (point-to-multipoint data transmissions) 124_1-124_3 promptly (e.g. within a support beacon interval) to one another.

In exemplary embodiments, the multicast transmission (point-to-multipoint data transmission) is prematurely decoupled and terminated for a group of participants while the other participants continue to be kept synchronized by supporting beacons.

3. Adaptation of the number of data packets to be received in a multicast data transmission depending on the receiving conditions of the participants in the

Communication systems

FIG. 14 shows a schematic block diagram of a base station 104 and a subscriber 106_1, for example of the communication system 100 shown in FIG. 3, according to an exemplary embodiment of the present invention.

For example, the subscriber 106_1 can have a transmitter (or transmission module; transmitter) 108_1 which is designed to send a data transmission to the base station 104. The transmitter 108_1 can be connected to an antenna 110_1 of the subscriber 106_1. The subscriber 106_1 can also have a receiver (or receiving module; receiver) 112_1, which is designed to receive a data transmission from the base station 104. The receiver 112_1 can be connected to the antenna 110_1 or a further antenna of the subscriber 106_1. The subscriber 106_1 can also have a combined transceiver (or transceiver module; transceiver).

For example, the base station 104 can have a receiver (or receiving module; receiver) 114 which is designed to receive a data transmission from the subscriber 106_1. The receiver 114 may be connected to an antenna 116 of the base station 104. The base station 104 can furthermore have a transmitter (or transmission module; transmitter) 118 which is designed to send a data transmission to the subscriber 106_1. The transmitter 118 can be connected to the antenna 116 or a further antenna of the base station 104. The base station 104 can also have a combined transceiver (or transceiver module; transceiver). The base station 104 can be configured to send out a multicast data transmission 124 (e.g. point-to-multipoint data transmission), e.g. to several participants in the communication system 100 (= real subset of participants in the communication system 100) or to all participants 106_1-106_n of the communication system 100 The multicast data transmission 124 can have a plurality of data packets 130_1-130J, where] is a natural number greater than or equal to two (or three), the plurality of data packets 130_1-130J being multiple transmissions of the same data packet (eg multicast data packets) . For example, the data packet 130_1 can be an initial transmission of a data packet (e.g. multicast data packet) of the multicast data transmission 124, the data packets 130_2-130J being retransmission of the same data packet (e.g. multicast data packet) of the multicast data transmission 124. For example, the plurality of data packets 130_1-130J can have the same useful data and / or error protection data or can be at least partially symbolically identical (except for a header, for example).

The subscriber 106_1 can be configured to receive and decode at least a first data packet of the plurality of data packets 130_1-130J of the multicast data transmission 124. The first data packet can, for example, be the first data packet 130_1 of the plurality of data packets 130_1-130J of the multicast data transmission 124 or any other data packet 130_2-130J of the plurality of data packets 130_1-130J of the multicast data transmission 124.

Subscriber 106_1 can further be configured to determine whether subscriber 106_1 meets a reception criterion. The reception criterion can e.g. (1) a successful decoding of the first data packet, (2) a signal-to-noise ratio of a received signal of the first data packet or a previous transmission by the base station (e.g. downlink data transmission, multicast transmission, support beacon transmission), and / or (3) a received field strength (e.g. RSSI = Received Signal Strength Indication, dt. relative quality of a received signal)) of a received signal of the first data packet or a previous transmission of the base station (e.g. downlink data transmission, multicast transmission, support beacons Transmission).

The subscriber 106_1 can further be configured, if the subscriber 106_1 meets the reception criterion, not to receive any further data packet 130_2-130J of the plurality of data packets 130_1-130J of the multicast data transmission 124, and for example to switch from a normal operating mode to an energy-saving mode switch. The subscriber 106_1 can furthermore be configured to receive at least one second data packet of the plurality of data packets 130_1-130J of the multicast data transmission 124 if the subscriber 106_1 does not meet the reception criterion. The second data packet can be any other data packet of the plurality of data packets 130__1-130J than the first data packet, such as one of the data packets 130_2-130J.

For example, the plurality of data packets 13Q_1-130J of the multicast data transmission 124 can each be provided with error protection data, whereby the subscriber 106_1 can be configured so that if the subscriber 106_1 does not meet the reception criterion and a decoding of the first data packet (e.g. 13Q_1) is unsuccessful was to combine the first data packet (e.g. 130_1) and the at least one second data packet (e.g. 130_2) in order to achieve a higher code gain during decoding by combining the first data packet (e.g. 130_1) and the at least one second data packet (e.g. 130_2) achieve.

In exemplary embodiments, the point-to-multipoint data transmission 124 can have a plurality of sub-data packets which are transmitted in a time and / or frequency distributed according to a time and / or frequency hopping pattern (telegram splitting transmission method), as has already been done was explained in detail in Section 1 above. In this case, the plurality of data packets 130_1-130J multiple transmissions to the same sub-data packet to be the plurality of sub-data packets. ^'

Although multicast data transmission is shown in FIG. 14, it should be pointed out that in exemplary embodiments, instead of multicast data transmission, downlink data transmission can also be used.

In exemplary embodiments, the subscriber 106_1 can, as already explained in detail above in Sections 1 and 2, send an uplink data transmission 120 to the base station 104, and in order to be synchronized in time (e.g. and in frequency) with the sent uplink data transmission 120 to receive a downlink data transmission 122 from the base station (see, for example, FIG. 6 or FIG. 10), the downlink data transmission having signaling information, wherein the subscriber 106_1 can be configured to use the signaling information to initiate the multicast data transmission 124 to recieve. The signaling information can include, for example, information about a point in time, a frequency channel and / or a hop pattern of the multicast data transmission 124 (see section 1), or also information about a point in time, a frequency channel and / or a hop pattern of one of the multicast data transmissions preceding support beacon data transmission 123 (see section 2), which in turn has information about a point in time, a frequency channel and / or a hop pattern of the multicast data transmission 124 or a further support beacon data transmission preceding the multicast data transmission 124.

Embodiments of the subscriber 106_1 shown in FIG. 14 and / or the base station shown in FIG. 14 can be used, for example, in a communication system as defined in the ETSI TS 103357 standard [4].

The plurality of data packets 13CM-130J can be multiple transmissions of the same so-called radio burst (German sub-data packet).

An ETSI TS 103 357 downlink data transmission has radio bursts with a length / duration of a maximum of 21 ms. The pause between the radio bursts averages 232 ms. A continuous transmission without violating the duty cycle in the ISM bands in Europe would be possible. In order to make the multicast data transmissions (or broadcast data transmissions) more efficient, the listen times for subscribers with good (or better) reception conditions can be reduced (or even minimized). Subscribers with good reception conditions are those subscribers who, for example, have a short distance from the base station and correspondingly good reception conditions (eg high SNR). Subscribers with poor (or worse) reception conditions, on the other hand, are those subscribers who are, for example, in the edge areas (for example at the end) of a radio cell and accordingly have poor reception conditions (for example low SNR). So that the subscribers with poor reception conditions can also be reached (ie can receive the multicast data transmission), a data rate and / or a channel coding of the transmission can be adapted. For example, starting from a transmission with a high data rate and low channel coding (ie high code rate), the data rate can be reduced and / or the channel coding can be increased (ie the code rate can be reduced). Furthermore, or alternatively, repetitions can be used in order to enable so-called maximum ration combining (MRC, i.e. maximum rate combination) on the receiver side to increase the range, as shown in FIG. 15 shows a schematic view of the transmission of eight data packets 130_1-

130_8, with a first data packet 130_1 being an initial transmission of a so-called radio burst, and the other data packets 130_2-130_8 being repetitive transmissions of the same radio burst, according to an exemplary embodiment.

Although FIG. 15 shows, by way of example, seven repetition transmissions of the one radio burst, it should be pointed out that the number of repetition transmissions is scalable, e.g. as a function of the reception conditions of the subscribers in the communication system.

In embodiments, the data rate of the repeat transmissions 130_2-130_8 can also be scalable. For example, the data rate of the repeat transmissions 130_2-130_8 can be lower than a data rate of the first transmission 130_1. Furthermore, a data rate of a kth repetition transmission (e.g. the second repetition transmission 130_3) can be lower than a data rate of a k-1th repetition transmission (e.g. the first repetition transmission 130_2).

In embodiments, a code rate of the repetitive transmissions 130_2-130_8 can also be scalable. For example, a code rate of the repeat transmissions 130_2-130_8 can be lower than a code rate of the first transmission 130_1. Furthermore, a code rate of a kth repetition transmission (e.g. the second repetition transmission 130_3) can be lower than a code rate of a k-1th repetition transmission (e.g. the first repetition transmission 130_2).

In other words, FIG. 15 shows a scalable radio burst length. A radio burst in downlink is shown in detail in FIG. 15. The radio burst 130_1 (e.g. according to ETSI TS 103357) can have a higher data rate, e.g. 19042.968 kSym / s (baud) than the radio

Bursts 130_ 2-130_ 8, which are repetitions of the same radio burst

130 _ 1 acts. As the number of repetitions increases, the radio burst duration can be increased and the sensitivity reduced accordingly. Participants with good reception conditions can, for example, only receive the first radio burst 13CM (initial transmission) and switch off after receiving the first radio burst 130_1 or switch to an energy-saving mode. Subscribers with poorer reception conditions can receive one or possibly more of the repetitions shown in FIG. 15 (for example all of the repetitions shown in FIG. 15) in order to obtain the necessary or full range (ie to receive the transmission successfully). Furthermore, participants with good (or better) reception conditions only receive one (or more) of the radio bursts 130_1-130_8 in order to reduce the on times. Even longer radio bursts generally make little sense in most application scenarios with battery-operated participants, since this would pose a problem in terms of energy buffering. Even shorter on-times than for receiving the first radio burst 130_1 generally also make no sense, since the PLL settling times would represent the bottleneck and thus effectively no further shortening of the on-times could be achieved.

In exemplary embodiments, subscribers with good reception conditions can only receive part of the radio bursts, e.g. one (or more) of the radio bursts, such as the first radio burst 130_1. Participants with poor reception conditions can also receive (at least part of) the repetitions of the radio burst.

In exemplary embodiments, a subscriber can determine the number of retransmissions to be received as follows. For example, the subscriber 106_1 can start with the first radio burst 130_1 (initial transmission) and try how many retransmissions for successful decoding (e.g. based on error detection (e.g. CRC (CRC = Cyclic Redundancy Check)) or an authentication) required are. Of course, the subscriber 106_1 can also receive all radio bursts 130_1-130_8 (i.e. first transmission and all retransmissions) and try how many retransmissions are required for successful decoding or authentication. Furthermore, a subscriber 106__1 can also receive one or more repetitions without using them, for example in order to have some margin in the event of a fault in the channel. Furthermore, based on an RSSI (RSSI = Received Signal Strength Indication, German indicator for the received field strength) or SNR (SNR = Signal-to-Noise Ratio), how much margin margin) on the budget link would be necessary.

In exemplary embodiments, subscribers with good reception conditions and subscribers with poor reception conditions can use identical symbols, such as the first radio burst 130_1 (see FIG. 15) or the other radio bursts 130 2 130_8 (see FIG. 15).

In exemplary embodiments, reception (for example further radio bursts) can be terminated after successful decoding. For example, the reception after a respective radio burst can be terminated, for example after the first radio burst 130_1 in FIG. 15.

In embodiments, in the event of a disturbance in the channel, further radio bursts can be received and used, for example, for successful decoding (e.g. of the user data).

In exemplary embodiments, the base station 104 can adapt a number of retransmissions as a function of a maximum required range.

In exemplary embodiments, an RSSI distribution can be viewed up-to-date from all participants in the communication system. In exemplary embodiments, this can be compared with RSSI level recordings from the last period (e.g. months). In embodiments, the base station can concentrate on the remote subscriber. In exemplary embodiments, the base station can wait until the remote subscribers are out of a fading hole, for example, and then address all subscribers (i.e. start the transmission of the multicast data transmission). Alternatively, the base station can now address those subscribers who have just got out of the fading hole (i.e. start the transmission of the multicast data transmission) and wait for the others.

4, group participants depending on the reception conditions and address them in groups

16 shows a schematic block diagram of a base station 104 and a subscriber 106_1, for example of the communication system 100 shown in FIG. 3, according to an exemplary embodiment of the present invention.

For example, the subscriber 106_.1 can have a transmitter (or transmitter module; transmitter)

108 _ 1, which is designed to send a data transmission to the base station 104. The transmitter 108_1 can be connected to an antenna 110_1 of the subscriber 106_1. Subscriber 106_1 can also have a receiver (or receiving module; receiver)

112 _ 1, which is designed to receive a data transmission from the base station 104. The receiver 112_1 can be connected to the antenna 10_1 or a further antenna of the subscriber 106_1. The subscriber 106_1 can also have a combined transceiver (or transceiver module; transceiver). For example, the base station 104 can have a receiver (or receiving module; receiver) 114 which is designed to receive a data transmission from the subscriber 106_1. The receiver 114 may be connected to an antenna 116 of the base station 104. The base station 104 can furthermore have a transmitter (or transmission module; transmitter) 118 which is designed to send a data transmission to the subscriber 106_1. The transmitter 118 can be connected to the antenna 116 or a further antenna of the base station 104. The base station 104 can also have a combined transceiver (or transceiver module; transceiver).

As already explained in detail above in section 1, the subscriber 106_1 can be configured to send an uplink data transmission 120 to the base station 104 and to synchronize a downlink in terms of time (and, for example, frequency) with the sent uplink data transmission 120 - Receive data transmission 122 from base station 104.

Accordingly, the base station 104 can be configured to receive the uplink data transmission 120 from the subscriber 106_1 and to transmit the downlink data transmission 122 to the subscriber 106_1 synchronized in time (and e.g. in frequency) with the sent uplink data transmission 120.

The downlink data transmission 122 here has at least one of first signaling information and second signaling information, the first

Signaling information signals a subsequent first multicast data transmission 124_1 or a further data transmission preceding the first multicast data transmission 124_1 (e.g. support beacon data transmission, see section 2), and the second signaling information signaling a subsequent second multicast data transmission 124_2 or one of the second multicast Data transmission 124_2 signals previous further data transmission (eg support beacon data transmission, see section 2).

The base station 104 can be designed to send the first multicast data transmission 124_1 in accordance with the first signaling information and to send the second multicast data transmission 124_2 in accordance with the second signaling information.

The first multicast data transmission 124_1 and the second point-to-multipoint data transmission 124_2 can differ with regard to at least one of transmission times,

Transmission frequencies, differentiate the frequency and / or time hopping patterns used.

The first multicast data transmission 124_1 can be intended for subscribers with good reception conditions, while the second multicast data transmission is intended for subscribers with poor reception conditions.

Thus, in exemplary embodiments, the second multicast data transmission 124_2 can have a lower code rate and / or data rate than the first multicast data transmission 124_1, for example in order to allow the second multicast data transmission 124_2 to get through compared to the first multicast data transmission 124_1 with regard to subscribers of the communication system increase that do not meet a reception quality criterion.

In embodiments, subscriber 106_1 can be assigned to one of the two multicast data transmissions 124_1 and 124_2 by base station 104 or by subscriber 106_1 himself. In the following, exemplary embodiments are first described in which the assignment of the subscriber 106_1 to one of the two multicast data transmissions 124_1 and 124_2 by the base station 104 takes place, before exemplary embodiments are subsequently described in which the assignment of the subscriber 106_1 to one of the two multicast -Data transmissions 124_1 and 124_2 are carried out by the subscriber 106_1 himself.

In exemplary embodiments, the base station 104 can assign the subscriber 106_1 to one of the two multicast data transmissions 124_1 and 124_2 depending on a reception quality of subscriber 106_1 (e.g. a quality with which data transmissions from the base station are received by subscriber 106_1). For example, the uplink data transmission 120 of the subscriber 106_1 can have information about the reception quality of the subscriber 106_1. The subscriber 106_1 can determine the reception quality, for example, based on a previous data transmission by the base station 104, such as a previous downlink data transmission or multicast data transmission. Alternatively, the base station 104 can estimate the reception quality of the subscriber 106_1, e.g. based on the uplink data transmission 120 of the subscriber 106_1.

In embodiments, the base station 104 can be configured, if the reception quality of the subscriber 106_1 meets a first reception quality criterion, the To provide downlink data transmission with the first signaling information so that the subscriber 106_1 can receive the first multicast data transmission 124_1 based on the first signaling information, or if the reception quality of the subscriber 104__1 does not meet the first reception quality criterion or the reception quality of the subscriber 104_1 a second The reception quality criterion is met to provide the downlink data transmission with the second signaling information so that the subscriber 106_1 can receive the second multicast data transmission 124_1 based on the second signaling information.

The first reception quality criterion can indicate, for example, that the reception quality of the subscriber 106_1 is greater than or equal to a reception quality threshold or lies within a first reception quality range.

The second reception quality criterion can indicate, for example, that the

The reception quality of the subscriber 106_2 is less than the reception quality threshold or lies within a second reception quality range, the first reception quality range and the second reception quality range being different.

In exemplary embodiments, the base station can be configured to dynamically adapt the first reception quality criterion (and / or the second reception quality criterion), e.g. depending on an occupancy of the frequency band used, e.g. by participants in the communication system and / or participants in other communication systems. Alternatively, the first reception quality criterion (and / or the second reception quality criterion) can be permanently specified.

As already mentioned at the beginning, the assignment of the subscriber 106_1 to one of the two multicast data transmissions 124_1 and 124_2 can alternatively also be made by the subscriber 106_1 himself.

Thus, in exemplary embodiments, the subscriber 106_1 can be configured to determine a reception quality based on the downlink data transmission 122 or a previous data transmission of the base station 104 (e.g. previous downlink data transmission or multicast data transmission), and to determine a reception quality as a function of the determined reception quality to receive one of the first multicast data transmission 124_1 based on the first signaling information and the second multicast data transmission 124_2 based on the second signaling information (In this case, the downlink data transmission can be both the first

Have signaling information as well as the second signaling information).

For example, the subscriber can be configured to receive the first multicast data transmission 124_1 based on the first signaling information if the determined reception quality meets a first reception quality criterion and / or to receive the determined reception quality if the determined reception quality does not meet the first reception quality criterion second reception quality criterion is met to receive the second multicast data transmission 124_2 based on the second signaling information, wherein the first reception quality criterion and the second

Reception quality criteria are different.

The first reception quality criterion can, for example, indicate that the

The reception quality of the subscriber 106_1 is greater than or equal to a reception quality threshold or lies within a first reception quality range.

The second reception quality criterion can indicate, for example, that the

In exemplary embodiments, the first reception quality criterion (and / or the second reception quality criterion) can be permanently specified. Alternatively, the downlink data transmission 122 can have information about the first reception quality criterion (and / or the second reception quality criterion).

The exemplary embodiments described here make it possible to address subscribers with good (or better) reception conditions and subscribers with poor (or worse) reception conditions on different frequencies and possibly at different times and with different data rates / encodings, and to control them in such a way that they respond to the respective different frequencies received.

17 shows a schematic view of an occupancy of a communication channel during the transmission of two multicast data transmissions for subscribers with good (or better) reception conditions and subscribers with poor (or worse) reception conditions, according to an exemplary embodiment. As can be seen in FIG. 17, the subscriber 106 receives a downlink data transmission 122 synchronized in terms of time and frequency with the sent uplink data transmission 120, the downlink data transmission 122 at least one of a first signaling information for receiving a first multicast Data transmission 124_1 and a second signaling information item for receiving a second multicast data transmission 124_2.

In FIG. 17, it is assumed by way of example that the first multicast data transmission 124_1 is transmitted divided into two multicast data transmission parts 125_1,1 and 125_1, 2, the two multicast data transmission parts 125_1,1 and 125_1, 2 each together with one Support beacons 123_1, 1 and 123_1,2 of the first multicast data transmission 124_1 are transmitted (see section 2, e.g. FIG. 12), and that the second multicast data transmission 124_2 is transmitted divided into two multicast data transmission parts 125_2,1 and 125_2,2 The two multicast data transmission parts 125_2,1 and 125_2,2 are each transmitted together with a support beacon 123_2, 1 and 123_2,2 of the second multicast data transmission 124_2.

In other words, FIG. 17 shows a grouping (for example clustering) of subscribers with good reception conditions and subscribers with poor reception conditions, for example for different multicast data transmissions 124_1 and 124_2. 17 shows in detail how subscribers are informed that a first multicast data transmission 124_1 for subscribers with good reception conditions is taking place on a first frequency and a second multicast data transmission 124_2 for subscribers with poor reception conditions is taking place at a second frequency. In this case, the subscribers can be assigned to a specific cluster (for example a group (subscribers with good reception conditions or subscribers with poor reception conditions)) from the base station 104. Alternatively, the subscriber 106_1 can decide for himself which cluster the subscriber will join (and thus, for example, which of the multicast data transmissions 124_1 or 124_2 the subscriber receives). Although only two clusters are shown in FIG. 17, it should be pointed out that any number of clusters (for example groups of subscribers with different reception conditions) can exist. The base station can, for example, signal in the downlink message 122 how many clusters there are and for which reception conditions (eg link budget / sensitivity) the clusters are intended. For example, radio bursts with a length of 2.5 ms and a sensitivity of -128.4 dBm can be provided for a first cluster, and radio bursts with a length of 21 ms and a sensitivity of -137.4 dB are provided for a second cluster. The subscriber can usually receive the downtink data transmissions with a sensitivity of -137.4 dBm. If the If the participant estimates an SNR of> 15 dB, the participant can also switch to the frequencies of the participants with good reception conditions. If the SNR drops, for example due to fading, the subscriber should be able to switch to the frequencies of the subscribers with poor reception conditions. In exemplary embodiments, the support jaws can therefore have the frequencies / times for all clusters.

In embodiments, the participants can be divided into clusters (e.g. groups). Each cluster uses different times / frequencies in order to reduce (or even minimize) a reception time of the participants with good reception conditions.

5. Cvcle padding

18 shows a schematic block diagram of a base station 104 and a subscriber 106_1, for example of the communication system 100 shown in FIG. 3, according to an exemplary embodiment of the present invention.

For example, the subscriber 106_1 can have a transmitter (or transmission module; transmitter) 108_1 which is designed to send a data transmission to the base station 104. The transmitter 108_1 can be connected to an antenna 110_1 of the subscriber 106_1. Subscriber 106_1 can also have a receiver (or receiving module; receiver)

112 _ 1, which is designed to receive a data transmission from the base station 104. The receiver 112_1 can be connected to the antenna 110_1 or a further antenna of the subscriber 106_1. The subscriber 106_1 can also have a combined transceiver (or transceiver module; transceiver).

For example, the base station 104 can have a receiver (or receiving module; receiver) 114 which is designed to receive a data transmission from the subscriber 106_1. The receiver 114 may be connected to an antenna 116 of the base station 104. The base station 104 can furthermore have a transmitter (or transmission module; transmitter) 118 which is designed to send a data transmission to the subscriber 106_1. The transmitter 118 can be connected to the antenna 116 or a further antenna of the base station 104. The base station 104 can also have a combined transceiver (or transceiver module; transceiver).

As already explained in detail above in section 1, the subscriber 106_1 can be configured to send an uplink data transmission 120 to the base station 104 and to synchronize in time (and e.g. in frequency) with the transmitted uplink data. Data transmission 120 to receive a downlink data transmission 122 from the base station 104.

Accordingly, the base station 104 can be configured to receive the uplink data transmission 120 from the subscriber 106_1 and to send the downlink data transmission 122 to the subscriber 106_1 synchronized in time (and e.g. in frequency) with the sent uplink data transmission 120, wherein the downlink data transmission 124 has signaling information, wherein the subscriber 106_1 can be configured to receive the multicast data transmission 124 based on the signaling information.

The signaling information can for example include information about a point in time, a frequency channel and / or a hop pattern of the multicast data transmission 124 (see section 1), or also information about a point in time, a frequency channel and / or a hop pattern of one of the multicast data transmission preceding support beacon data transmission 123 (see section 2), which in turn has information about a point in time, a frequency channel and / or a hop pattern of the multicast data transmission 124 or a further support beacon data transmission preceding the multicast data transmission 124.

In exemplary embodiments, the base station 104 can be configured to initially only transmit a part 125_1 of the multicast data transmission 124 or to interrupt the ongoing multicast data transmission 124 (eg after the transmission of a part 125_1 of the multicast data transmission 124) to initiate a transmission to enable at least one other data transmission 126.

The at least one other data transmission 126 can be, for example, a second multicast data transmission which has a higher priority than the (first) multicast data transmission 124 To resume transmission of the second multicast data transmission (ie to transmit a second part 125_2 of the multicast data transmission 124), provided that an available duty cycle of the base station 104 is sufficient for resuming the first multicast data transmission. Of course, it is just as possible that the second multicast data transmission is scheduled for transmission, and the first multicast data transmission 124 or a part 125_1 of the multicast data transmission 124 is only transmitted when a duty cycle is available the base station 104 is sufficient for this. Alternatively, the other data transmissions can also be confirmations of receipt from participants in the communication system, which confirm successful receipt of the first part 125_1 of the multicast data transmission 124. The latter is particularly useful when the multicast data transmission 124 is a relatively long multicast data transmission 124.

The duty cycle is a critical parameter of the communication system. As already mentioned, according to the standard, a duty cycle of 10% must not be exceeded for a specific belt in Europe. Several communication systems (e.g. radio systems) can coexist at the same time (see Fig. 3). Depending on the urgency of the use cases, the duty cycle can be more or less completely used up (e.g. for subscriber-specific downlink messages). The duty cycle can thus be monitored in the base station. Each transmission event is recorded (e.g. noted) together with the respective transmission time (on air time) and the respective time stamp. All transmission events within the last hour (or day, month, year) are accumulated with the respective transmission times in order to calculate the used duty cycle. As time progresses, the duty cycle consumption is updated.

In exemplary embodiments, the transmissions (e.g. multicast transmissions) can be divided according to priorities. This means that there may be transmissions (e.g. with higher priority) that should be completed as quickly as possible. For other transmissions with a lower priority, however, it may be sufficient if these are only fully transmitted after days or months. For example, such transmissions or use cases can be divided into foreground transmissions and background transmissions. The (e.g. available) duty cycle can thus initially be assigned to the foreground transmissions with the higher priority. The background transmissions, on the other hand, are only scheduled if there is enough duty cycle available. It is also possible for background transmissions to be transmitted (always) if they are available. If a foreground transmission with a higher priority arrives, the background transmission is interrupted and the foreground transmission is transmitted instead.

19 shows a schematic view of an occupancy of a communication channel during the transmission of a first multicast data transmission 124_1 and a second multicast data transmission 124_2, the second multicast data transmission 124_2 having a higher priority than the first multicast data transmission 124_1, according to a Embodiment. In other words, Fig. 19 shows a transmission with a higher priority.

As can be seen in FIG. 19, an ongoing transmission of the first multicast data transmissions 124_1 can be interrupted if a second multicast data transmission 124_2 with a higher priority is pending transmission and the second multicast data transmission 124_2 is transmitted instead. After the transmission of the second multicast data transmissions 124_2, the transmission of the first multicast data transmissions 124_1 can be resumed if an available duty cycle of the base station is sufficient for this.

In FIG. 19, it is assumed by way of example that the first multicast data transmission 124_1 is divided into four multicast data transmission parts 125_1,1-

125 _ 1, 4 is transmitted, the multicast data transmission parts 125_1, 1 and 125_1, 2 being transmitted before the second multicast data transmission 124_2 and which the multicast

Data transmission parts 125_ 1, 3 and 125_1, 4 after the second multicast data transmission

124_2 are transferred. Furthermore, in FIG. 19 it is assumed by way of example that the second multicast data transmission 124_2 is divided into two multicast

Data transmission parts 125 _ 2,1 and 125_2,2 is transmitted. Furthermore, in FIG. 19 it is assumed by way of example that the multicast data transmission parts 125_1, 1 -125_1, 4 of the first multicast data transmission 124_1 each together with a support beacon 123_1, 1 -

123 _ 1, 4 of the first multicast data transmission 124_1 are transmitted (see. Section 2, e.g. FIG. 12), and that the multicast data transmission parts 125_2,1 and 125_2,2 of the second multicast data transmission 124_2 each together with a support beacon 123_2 , 1 and 123_2,2 of the second multicast data transmission 124_2 are transmitted (see section 2, e.g. FIG. 12).

In embodiments, depending on the priority of the data to be transmitted, filling can be carried out according to a block limit (unidirectional piggy backing (i.e. appending data to a message to be transmitted)).

20 shows a schematic view of an occupancy of a communication channel during the transmission of a multicast data transmission 124_1 of a base station, the

Muiticast data transmission 124_1 divided into at least two multicast sub-

Data transmissions 125_1-125_2Q48 is transmitted, wherein after the transmission of at least a first multicast partial data transmission, acknowledgments of receipt 126 are transmitted from subscribers that a ^' successful reception of the at least one first Confirm multicast partial data transmission, according to an exemplary embodiment. In other words, FIG. 20 shows an uplink with ACK / NACK after N blocks.

In FIG. 20, it is assumed by way of example that the multicast data transmission 124_1 is transmitted divided into 2048 multicast partial data transmissions 125_1-125_2048, with acknowledgments of receipt (ACK / NACK) 126 are transmitted by the participants of the communication system 100, which confirm a successful or unsuccessful reception of the first 1024 multicast partial data transmissions 125_1 -125__1024. In FIG. 19, it is also assumed by way of example that multicast partial data transmissions 125_1-125_2Q18 are transmitted together with a support beacon 123_1-123_2048 of the multicast data transmission 124 (see section 2, e.g. FIG. 12).

Referring to Fig. 20, it is assumed by way of example that user data (e.g. a firmware update) with a size of e.g. 256 kbytes are to be transmitted. The 256 kbytes correspond to 262144 bytes. Per block (= multicast partial data transmission, e.g. in the case of ETSI TS 103357, a maximum of 24 bytes may be transmitted. This would mean that 10923 blocks with 2380.371 kbaud would have to be transmitted. Each radio burst has a length of 21.43 ms, The average pause between the radio bursts is 217 ms, which guarantees 10%.

A block of radio bursts (e.g. a block of 18 radio bursts in ETSI TS 103 357) lasts roughly 4 seconds. This means that the firmware transfer takes 12.14 hours. In embodiments, the transmission of the multicast data transmission can therefore be interrupted again and again in order to check what has arrived. For example after 512 blocks (approx. 30 min).

In exemplary embodiments, a pause (e.g. between the multicast partial data transmission or radio bursts) can be greater than a transmission time of the radio bursts / duty cycle from the tape. For example, a maximum duty cycle of 10% can be permitted at 869.525 MHz. It follows that the pause should be at least ten times longer than the duration of the radio burst. This can be adjusted depending on the tape.

Furthermore, the success rate can be communicated from each downlink to the base station. Based on the success rate, the base station can decide whether to transmit the is stopped, moved or executed in the next 512 blocks. The success rate can be determined using the RSSI or PER, for example.

6 Further embodiments

The exemplary embodiments described below can be implemented or used on their own or in combination with the exemplary embodiments described above.

21 shows a flow diagram of a method 200 for receiving a data transmission in an uncoordinated communication system, according to an exemplary embodiment. The method 200 comprises a step 202 of receiving and decoding at least one first data packet of a plurality of data packets of the data transmission, the plurality of data packets being multiple transmissions of the same data packet. The method 200 further comprises a step of receiving, if a receiving criterion is met, not to receive any further data packets of the plurality of data packets of the data transmission. The method 200 further comprises a step of receiving, if the receiving criterion is met, at least one further data packet of the plurality of data packets of the data transmission.

22 shows a flow diagram of a method 210 for receiving a point-to-multipoint data transmission in an uncoordinated communication system, according to an exemplary embodiment of the present invention. The method 210 comprises a step 212 of sending an uplink data transmission. The method 210 further comprises a step 214 of receiving, synchronized in time with the sent uplink data transmission, a downlink data transmission, the downlink data transmission having a first signaling information item and a second signaling information item, the first signaling information item being a first point-to-multipoint Data transmission signals, and wherein the second signaling information signals a second point-to-multipoint data transmission. The method 210 further comprises a step 216 of determining a reception quality based on the downlink data transmission or a previous downlink data transmission or a previous point-to-multipoint data transmission. The method 210 further comprises a step 218 of receiving, depending on the determined reception quality, one of the first point-to-multipoint data transmission based on the first signaling information, and the second point-to-multipoint data transmission based on the first signaling information.

23 shows a flow diagram of a method 220 for sending point-to-multipoint data transmissions in an uncoordinated communication system, according to an exemplary embodiment of the present invention. The method 220 comprises a step 222 of receiving an uplink data transmission, the uplink data transmission being uncoordinated. The method 220 further comprises a step 224 of sending, synchronized in time with the received uplink data transmission, a downlink data transmission, the downlink data transmission having first signaling information and second signaling information, the first signaling information being followed by a first point-to-point. Signaled multipoint data transmission, and wherein the second signaling information signals a subsequent second point-to-multipoint data transmission. The method 220 further comprises a step 226 of sending the first point-to-multipoint data transmission in accordance with the first signaling information. The method 220 further comprises a step 228 of sending the second point-to-multipoint data transmission in accordance with the second signaling information, the second point-to-multipoint data transmission having a lower code rate and / or data rate than the first point-to-multipoint Data transmission in order to increase a probability of passage of the second point-to-multipoint data transmission compared to the first point-to-multipoint data transmission.

24 shows a flow diagram of a method 230 for sending point-to-multipoint data transmissions in an uncoordinated communication system, according to an exemplary embodiment. The method 230 includes a step 232 of receiving an uplink data transmission, the uplink data transmission being uncoordinated. The method 230 further comprises a step 234 of extracting information about a reception quality from the uplink data transmission or estimating a reception quality based on the uplink data transmission. The method 230 further comprises a step 236 of sending, synchronized in time with the received uplink data transmission, a downlink data transmission, the downlink data transmission being provided with first signaling information or second signaling information depending on the reception quality, the first signaling information signals a subsequent first point-to-multipoint data transmission, and wherein the second signaling information signals a subsequent second point-to-multipoint data transmission. The method 230 further comprises a step 238 of sending the first Point-to-multipoint data transmission according to the first signaling information. The method 230 further comprises a step 240 of sending the second point-to-multipoint data transmission in accordance with the second signaling information.

25 shows a flow diagram of a method 250 for transmitting point-to-multipoint data transmissions in an uncoordinated communication system, according to an exemplary embodiment. The method 250 includes a step 252 of transmitting a first point-to-multipoint data transmission. The method 250 further comprises a step 254 of aborting or pausing the transmission of the first point-to-multipoint data transmission if at least one second data transmission that has a higher priority than the transmission at the time of the transmission of the first point-to-multi-point data transmission first point-to-multipoint data transmission pending transmission. The method 250 further includes a step 256 of transmitting the second data transmission.

26 shows a flow diagram of a method 260 for transmitting point-to-multipoint data transmissions in an uncoordinated communication system, according to an exemplary embodiment. The method 260 includes a step 262 of transmitting a second point-to-multipoint data transmission within a transmission interval. The method 260 further comprises a step 264 of transmitting within the transmission interval at least part of a first point-to-multipoint data transmission, provided that a duty cycle of the base station for the transmission of the at least part of the first point-to-multipoint data transmission within the transmission interval Data transfer is sufficient.

27 shows a flow diagram of a method 270 for transmitting a point-to-multipoint data transmission in an uncoordinated communication system, according to an exemplary embodiment. The method 270 includes a step 272 of dividing the

Point-to-multipoint data transmission on at least two point-to-multipoint partial data transmissions. The method 270 further comprises a step 274 of transmitting at least one first point-to-multipoint partial data transmission of the at least two point-to-multipoint partial data transmissions to a plurality of subscribers in the communication system. The method 270 further comprises a step 276 of receiving acknowledgments of receipt from at least some of the plurality of participants, the acknowledgments of receipt confirming successful receipt of the at least one first point-to-multipoint partial data transmission. The method 270 further comprises a step 278 of determining, based on a number of received acknowledgments, a measure of success. The method 270 further comprises a step 280 of transmitting, if the measure of success meets a success criterion, at least one second point-to-multipoint partial data transmission of the at least two point-to-multipoint partial data transmissions to the plurality of subscribers in the communication system.

Embodiments of the present invention deal with multicast / broadcast transmissions in radio systems with non-coordinated participants. I In particular, concepts for synchronizing and keeping the participants (nodes) in sync in the run-up to a multicast ZBroadcast transmission are described. As described in section 1, the subscriber can be signaled about the multicast / broadcast transmission. Furthermore, by using support beacons, as described in section 2, it can be ensured that the participants (e.g. nodes) remain synchronized in terms of time and frequency.

The data is typically transmitted in the ISM bands. Depending on the exact belt selected, there are different restrictions with regard to the duty cycle. For example, at 869.525 MHz the band has a bandwidth of 250 kHz and the duty cycle of a subscriber or the base station may not exceed 10%. The 10% must be related to one hour and correspond to 360 of 3600 seconds.

The challenge is that the multicast data transmission is sent in such a way that the RF ON time (dt. Reception time) is reduced (or even minimized) for each participant and the transmission does not violate the available duty cycle.

Embodiments of the present invention increase the reliability of a multicast data transmission, reduce the reception time for subscribers with good reception conditions (e.g. close distance to the base station), and / or stop reception after successful decoding.

In the case of implementation examples, the available duty cycle is observed / monitored and an available gap is closed in order to increase the belt efficiency.

In exemplary embodiments, the downlink data transmission or multicast data transmission is only scheduled if the channel load is not too high and is otherwise delayed. In exemplary embodiments, a combined scheme of channel coding and repetitive transmissions is used to create scalability for different subscribers, so that subscribers with good reception conditions (eg with a short distance from the base station) can interrupt reception early.

In embodiments, feedback is given to the base station so that it can decide how to proceed.

In exemplary embodiments, various options are made available to the downlink receiver.

Embodiments of the present invention deal with a system (communication system) for digital. Transfer of data via a

Radio transmission system. The data sent are typically transmitted in several sub-frequency channels of the entire available bandwidth.

Embodiments of the present invention can be used in so-called non-coordinated networks (communication systems) in which the radio users transmit their data in an uncoordinated manner (without prior allocation of a radio resource).

Embodiments of the present invention can be used, for example, in a communication system as defined in the ETSI TS 103357 standard [4].

Embodiments provide a subscriber [e.g. Endpoint] one

Communication system, [wherein the communication system communicates wirelessly in a frequency band [e.g. ISM band] which is used by a plurality of communication systems [e.g. uncoordinated with one another], wherein the subscriber is designed to transmit data in an uncoordinated manner with respect to other subscribers and / or a To send base station of the communication system, wherein the subscriber is trained to receive a downlink data transmission from the base station in a time-synchronized manner to a sent uplink data transmission to the base station of the communication system, the downlink data transmission having signaling information, the subscriber being designed to receive a point-to-multipoint data transmission [e.g. multicast data transmission] from the base station based on the signaling information. In exemplary embodiments, the signaling information can include information about a point in time of the point-to-multipoint data transmission.

For example, the information about the point in time can be an absolute point in time, a relative point in time [e.g. a defined time span between the downlink data transmission and the point-to-multipoint data transmission] or information from which the absolute or relative point in time can be derived, such as a number of clock cycles of an oscillator of the subscriber.

In embodiments, the signaling information may also include information about a frequency channel [e.g. of the frequency band used by the communication system] of point-to-multipoint data transmission.

For example, the information about the frequency channel may be an absolute frequency channel or a relative frequency channel [e.g. a distance between a frequency channel of the downlink data transmission and a frequency channel of the point-to-multipoint data transmission].

In exemplary embodiments, the point-to-multipoint data transmission can have a plurality of sub-data packets that are transmitted in a current and or frequency according to a time and / or frequency hopping pattern, the signaling information also being information about the time and or Has frequency hopping pattern.

For example, the point-to-multipoint data transmission can be a telegram splitting-based data transmission. In the case of a telegram spitting-based data transmission, the data to be transmitted [e.g. [encoded] user data of the physical layer] divided into a plurality of sub-data packets, so that the plurality of sub-data packets each have only part of the data to be transmitted, the plurality of sub-data packets not contiguous, but rather in current and / or frequency are transmitted in a distributed manner in accordance with a time and / or frequency hopping pattern.

In exemplary embodiments, the information about the point in time of the point-to-multipoint data transmission can have a defined [eg deliberate or intentional] inaccuracy that is at least so great that a receiver-side synchronization to the point-to-multipoint data transmission to receive the point -to-multipoint data transmission is required, whereby the subscriber is trained to synchronize to the point to perform the point-to-multipoint data transmission in order to receive the point-to-multipoint data transmission.

In exemplary embodiments, the defined inaccuracy can be in the range from 1 to 10,000 symbol durations.

In exemplary embodiments, the defined inaccuracy can be a non-linear scaling [e.g. a logarithmic scaling], so that the inaccuracy is greater with increasing distance up to point-to-multipoint data transmission.

In embodiments, the downlink data transmission may further include clock correction information [e.g. B crystal offset in ppm applies to timers and frequency generators] for correcting a clock deviation of a clock generator of the subscriber, the subscriber being designed to correct a clock deviation of the clock generator based on the clock generator correction information.

In embodiments, the uplink data transmission can be a first uplink data transmission, the downlink data transmission being a first downlink data transmission, the signaling information being first signaling information, the first signaling information being a time period or point in time [e.g. rough point in time] for a second uplink data transmission [e.g. which follows the first uplink data transmission], the subscriber being designed to send the second uplink data transmission to the base station in the signaled period and to send a second downlink data transmission from the base station synchronized with the second uplink data transmission to receive, wherein the second downlink data transmission has a second signaling information, wherein the subscriber is designed to based on the second signaling information, the point-to-multipoint data transmission [eg Multicast data transmission].

In exemplary embodiments, the second signaling information item can include information about a point in time of the point-to-multipoint data transmission.

In exemplary embodiments, the second signaling information can also include information about a frequency channel [eg the frequency band used by the communication system] of the point-to-multipoint data transmission. In exemplary embodiments, the point-to-multipoint data transmission can have a plurality of sub-data packets which are transmitted in current and / or frequency according to a time and / or frequency hopping pattern, the second signaling information also being information about the time and or frequency hopping pattern.

In embodiments, the subscriber can be configured to, if the second downlink data transmission could not be received successfully [e.g. if the second downlink data transmission did not take place or was disturbed] to send a third uplink data transmission to the base station and to receive a third downlink data transmission from the base station synchronized in time with the third uplink data transmission, the third downlink data transmission comprises a third piece of signaling information, the subscriber being designed to carry out the point-to-multipoint data transmission [eg Multicast data transmission].

In embodiments, the first downlink data transmission or the second downlink data transmission can also have a clock correction information that describes a clock deviation of a clock of the subscriber in relation to a reference clock, wherein the subscriber is designed to use the point-to-multipoint data transmission to receive the clock correction information [e.g. to correct a timing deviation of the clock based on the clock correction information for receiving the point-to-multipoint data transmission].

In embodiments, the uplink data transmission can be a first uplink data transmission, the downlink data transmission being a first downlink data transmission, the signaling information being first signaling information, the first signaling information being information about a rough point-to-multipoint point in time -Data transmission, [eg where the information about the rough point in time of the point-to-multipoint data transmission is too imprecise for a reception of the point-to-multipoint data transmission], the subscriber being designed to read the point before the rough point in time -to-multipoint data transmission to send a fourth uplink data transmission to the base station and to receive a fourth downlink data transmission from the base station synchronized in time with the fourth uplink data transmission, the fourth downlink data transmission having fourth signaling information, the participant is designed to receive the point-to-multipoint data transmission [eg multicast data transmission] based on the fourth signaling information.

In exemplary embodiments, the fourth piece of signaling information can include information about a point in time of the point-to-multipoint data transmission.

In embodiments, the fourth signaling information may further include information about a frequency channel [e.g. of the frequency band used by the communication system] of the point-to-multipoint data transmission.

In embodiments, the point-to-multipoint data transmission can have a plurality of sub-data packets which are transmitted in current and / or frequency according to a time and / or frequency hopping pattern, the fourth signaling information also being information about the time and or frequency hopping pattern.

In exemplary embodiments, the first downlink data transmission or the fourth downlink data transmission can also have clock correction information for correcting a clock deviation of a clock of the subscriber, the subscriber being designed to correct a clock deviation of the clock based on the clock correction information.

In embodiments, the signaling information can be a first signaling information, wherein the first signaling information includes information about a point in time of a support beacon, wherein the subscriber is designed to receive the support beacon based on the first signaling information, the support beacon has a fifth signaling information, the Subscriber is designed, based on the fifth signaling information, the point-to-multipoint data transmission [eg Multicast data transmission].

In embodiments, the first signaling information may further include information about a frequency channel [e.g. of the frequency band used by the communication system] or a frequency offset of the support beam.

In exemplary embodiments, the fifth piece of signaling information can include information about a point in time of the point-to-multipoint data transmission. In exemplary embodiments, the fifth piece of signaling information can also include information about a frequency channel [eg the frequency band used by the communication system] of the point-to-multipoint data transmission.

In exemplary embodiments, the point-to-multipoint data transmission can have a plurality of sub-data packets which are transmitted in a time and / or frequency distributed according to a time and / or frequency hopping pattern, the fifth signaling information also being information about the time and or has frequency hopping patterns.

In embodiments, the downlink data transmission or the support beacon can also have clock correction information for correcting a clock deviation of a clock of the subscriber, the subscriber being designed to correct a clock deviation of the clock based on the clock correction information.

In exemplary embodiments, the subscriber can be designed to send data asynchronously to other subscribers and / or the base station of the communication system.

For example, the subscriber can be designed to send the uplink data transmission asynchronously to the base station.

In exemplary embodiments, the subscriber can be designed to send the uplink data transmission to the base station at a random or pseudo-random point in time.

In embodiments, the ^'uplink data transmission may comprise a plurality of sub-data packets in the time and frequency or in accordance with a time and / or frequency hopping pattern are transmitted distributed.

For example, the uplink data transmission can be a telegram splitting-based data transmission. In the case of telegram splitting-based data transmission, the data to be transmitted [e.g. (encoded) user data of the physical layer] are divided into a plurality of sub-data packets, so that the plurality of sub-data packets each have only part of the data to be transmitted, wherein the plurality of sub-data packets are not transmitted contiguously, but distributed in time and / or frequency in accordance with a time and / or frequency hopping pattern. In embodiments, the downlink data transmission can have a plurality of sub-data packets which are transmitted in a time and / or frequency distributed according to a time and / or frequency hopping pattern.

For example, the downlink data transmission can be a telegram splitting-based data transmission. In the case of data transmission based on telegram splitting, the data to be transmitted [e.g. (encoded) user data of the physical layer] divided into a plurality of sub-data packets, so that the plurality of sub-data packets each have only part of the data to be transmitted, the plurality of sub-data packets not contiguous, but in time and / or frequency are transmitted distributed according to a time and / or frequency hopping pattern].

In embodiments, the participant can be a sensor node or an actuator node.

In embodiments, the participant can be battery operated.

In exemplary embodiments, the participant can have an energy harvesting element for generating electrical energy.

Further embodiments provide a base station of a communication system [wherein the communication system is in a frequency band [e.g. ISM band] communicates wirelessly which is made up of a plurality of [e.g. communication systems that are not coordinated with one another], the base station being designed to receive an uplink data transmission from a subscriber of the communication system, the uplink data transmission being uncoordinated, the base station being designed to be time-synchronized with the received uplink data transmission of the subscriber to send a downlink data transmission to the subscriber, the downlink data transmission having signaling information, the signaling information signaling a subsequent point-to-multipoint data transmission or a further data transmission preceding the point-to-multipoint data transmission, the Base station is designed to carry out the point-to-multipoint data transmission in accordance with the signaling information [e.g. to a plurality of subscribers of the communication system, the subscriber being part of the plurality of subscribers].

In exemplary embodiments, the signaling information can include information about a point in time of the point-to-multipoint data transmission. For example, the information about the point in time can be an absolute point in time, a relative point in time [e.g. a defined time span between the downlink data transmission and the point-to-multipoint data transmission] or information from which the absolute or relative point in time can be derived, such as a number of clock cycles of a subscriber's oscillator.

In embodiments, the signaling information may also include information about a frequency channel [e.g. of the frequency band used by the communication system] of the point-to-multipoint data transmission.

For example, the point-to-multipoint data transmission can be a telegram splitting-based data transmission. In the case of data transmission based on telegram splitting, the data to be transmitted [e.g. [encoded] user data of the physical layer] divided into a plurality of sub-data packets, so that the plurality of sub-data packets each have only part of the data to be transmitted, the plurality of sub-data packets not contiguous, but rather in current and / or frequency are transmitted in a distributed manner in accordance with a time and / or frequency hopping pattern.

In exemplary embodiments, the information about the point in time of the point-to-multipoint data transmission can be of a defined [e.g. intentional or intentional] inaccuracy that is at least so great that a synchronization on the receiver side to the point-to-point

Multipoint data transmission is required to receive the point-to-multipoint data transmission. In exemplary embodiments, the defined inaccuracy can be in the range from 1 to 10,000 symbol durations.

In exemplary embodiments, the defined inaccuracy can be subject to non-linear scaling as a function of a time interval up to point-to-multipoint data transmission, so that the inaccuracy increases with increasing distance up to point-to-multipoint data transmission.

Data transfer is greater.

In embodiments, the base station can be designed to determine a clock deviation of a clock of the subscriber based on the uplink data transmission of the subscriber, the base station being designed to provide the downlink data transmission with clock correction information for correcting the clock deviation of the clock of the subscriber .

In embodiments, the base station can be designed to determine a clock deviation of a clock of the subscriber based on the uplink data transmission of the subscriber, the information about the point in time of the point-to-multipoint data transmission, which has the signaling information, the clock deviation of the clock of the Participant takes into account [e.g. such that the clock deviation of the clock generator is compensated], and / or wherein the information on the frequency channel of the point-to-multipoint data transmission comprising the signaling information takes into account the clock deviation of the clock generator of the subscriber [e.g. in such a way that the clock deviation of the clock generator is compensated].

In exemplary embodiments, the uplink data transmission can be a first uplink data transmission, the downlink data transmission being a first downlink data transmission, the signaling information being a first signaling information, the first signaling information being a time period or point in time [e.g. rough point in time] for a second Uplink data transmission [eg that follows the first uplink data transmission] is signaled, the base station being designed to receive the second uplink data transmission from the subscriber in the signaled period and a second downlink synchronized with the second uplink data transmission -Send data transmission to the subscriber, the second downlink data transmission having a second signaling information, the second signaling information signaling the subsequent point-to-multipoint data transmission, [eg where the second uplink data transmission and / or di e second downlink data transmission is the further data transmission], the base station being designed in order to send the point-to-multipoint data transmission according to the second signaling information [eg to a plurality of subscribers of the communication system, the subscriber being part of the plurality of subscribers].

In embodiments, the second signaling information may further include information about a frequency channel [e.g. of the frequency band used by the communication system] of the point-to-multipoint data transmission.

In exemplary embodiments, the point-to-multipoint data transmission can have a plurality of sub-data packets which are transmitted in a distributed manner in the time and / or frequency according to a time and / or frequency hopping pattern, the second signaling information also being information about the time and / or frequency. and or has frequency hopping patterns.

In exemplary embodiments, the base station can be designed to determine a clock deviation of a clock of the subscriber based on the second uplink data transmission of the subscriber, the base station being designed to provide the second downlink data transmission with clock correction information for correcting the clock deviation of the clock of the subscriber to provide.

In embodiments, the base station can be configured based on the first or second uplink data transmission ^'of the subscriber to determine a clock drift of a clock of the subscriber, wherein the information about the timing of the point-to-multipoint data transmission, having the second signaling information the clock deviation of the subscriber's clock is taken into account [eg in such a way that the clock deviation of the clock is compensated].

In exemplary embodiments, the uplink data transmission can be a first uplink data transmission, the downlink data transmission being a first downlink data transmission, the signaling information being first signaling information, the first signaling information being information about a rough point in time of the point-to-multipoint -Data transmission, [eg where the information about the rough point in time of the point-to-multipoint data transmission for a reception of the point-to-multipoint data transmission is too imprecise], wherein the base station is designed to receive a fourth uplink data transmission from the subscriber before the rough point in time of the point-to-multipoint data transmission and to be synchronized with the time fourth uplink data transmission to send a fourth downlink data transmission to the subscriber, the fourth downlink data transmission having fourth signaling information, the fourth signaling information signaling the subsequent point-to-multipoint data transmission, [e.g. where the fourth uplink data transmission and / or the fourth downlink data transmission is the further data transmission], the base station being designed to carry out the point-to-multipoint data transmission according to the fourth signaling information [eg to a plurality of subscribers of the communication system, the subscriber being part of the plurality of subscribers is to send].

In exemplary embodiments, the point-to-multipoint data transmission can have a plurality of sub-data packets which are transmitted in current and / or frequency according to a time and / or frequency hopping pattern, the fourth signaling information also being information about the time and or frequency hopping pattern.

In embodiments, the base station can be designed to determine a clock deviation of a clock of the subscriber based on the fourth uplink data transmission of the subscriber, the base station being designed to provide the fourth downlink data transmission with clock correction information to correct the clock deviation of the clock of the subscriber to provide.

In embodiments, the base station can be designed to determine a clock deviation of a clock of the subscriber based on the fourth uplink data transmission of the subscriber, the information about the point in time of the point-to-multipoint data transmission, which has the fourth signaling information, the clock deviation of the Clock of the subscriber takes into account [e.g. in such a way that the clock deviation of the clock is compensated], and / or wherein the information about the frequency channel of the point-to-multipoint data transmission, which has the fourth signaling information, takes into account the clock deviation of the clock of the subscriber [e.g. such that the clock deviation of the clock is compensated].

In exemplary embodiments, the signaling information can be first signaling information, the first signaling information comprising information about a point in time of a support beacon, the base station being designed to provide the support beacon in accordance with the first signaling information [e.g. to a plurality of subscribers of the communication system, the subscriber being part of the plurality of subscribers], the support beacon having fifth signaling information, the fifth signaling information signaling the subsequent point-to-multipoint data transmission, [e.g. whereby the support beacon is the further data transmission].

In embodiments, the first signaling information may further include information about a frequency channel [e.g. the one used by the communication system

Frequency band] of the support beam.

In exemplary embodiments, the fifth signaling information item can include information about a point in time of the point-to-multipoint data transmission.

In embodiments, the fifth signaling information may further include information about a frequency channel [e.g. the one used by the communication system

Frequency band] of point-to-multipoint data transmission.

In exemplary embodiments, the point-to-multipoint data transmission can have a plurality of sub-data packets which are transmitted in a time and / or frequency distributed manner in accordance with a time and / or frequency hopping pattern, the fifth signaling information also being information about the time and / or frequency. and or has frequency hopping patterns.

In embodiments, the base station can be designed to determine a clock deviation of a clock of the subscriber based on the subscriber's uplink data transmission, the base station being designed to provide the downlink data transmission or the support beacon with clock correction information to correct the clock deviation of the clock of the participant. In exemplary embodiments, the base station can be designed to determine a clock deviation of a clock of the subscriber based on the subscriber's uplink data transmission, the information about the point in time of the point-to-multipoint data transmission, which has the fifth signaling information, being the clock deviation of the clock of the participant is taken into account [eg in such a way that the clock deviation of the clock generator is compensated].

Further exemplary embodiments create a method for operating a subscriber in a communication system. The method comprises a step of sending an uplink data transmission to a base station of the communication system, the uplink data transmission being uncoordinated. The method further comprises a step of receiving a downlink data transmission from the base station in a time-synchronized manner with the uplink data transmission, the downlink data transmission having signaling information. The method further comprises a step of receiving a point-to-multipoint data transmission [e.g. Multicast data transmission] from the base station based on the signaling information.

Further exemplary embodiments create a method for operating a base station of a communication system. The method comprises a step of receiving an uplink data transmission from a subscriber in the communication system, the uplink data transmission being uncoordinated. Furthermore, the method comprises a step of sending a downlink data transmission to the subscriber synchronized in time with the uplink data transmission, the downlink data transmission having signaling information, the signaling information being a subsequent point-to-multipoint data transmission or one of the point-to-point -Multipoint data transmission signals previous further data transmission. The method further comprises a step of sending the point-to-multipoint data transmission according to the signaling information [e.g. to a plurality of subscribers of the communication system, the subscriber being part of the plurality of subscribers].

Embodiments create a subscriber of a communication system, [wherein the communication system communicates wirelessly in a frequency band [e.g. ISM band] which is used by a plurality of [e.g. mutually uncoordinated] communication systems], the subscriber being designed to transmit data in an uncoordinated manner with respect to others To send subscribers and / or a base station of the communication system, wherein the subscriber is designed to send one or to receive several [e.g. at least two] support beacons from the base station of the communication system, [e.g. which precede a point-to-multipoint data transmission,] wherein the one or more support beacons [e.g. each] have synchronization information [e.g. for the synchronization of the subscriber [e.g. on the respective support beacon, on a point-to-multipoint data transmission of the base station and / or on at least one further support beacon [eg that precedes the point-to-multipoint data transmission]]], the subscriber being designed to use the Synchronization information to receive a point-to-multipoint data transmission from the base station.

In embodiments, the subscriber can be designed to receive a downlink data transmission from the base station synchronized in time with a sent uplink data transmission to the base station, the downlink data transmission having signaling information, the signaling information being the transmission of the support beacon or at least one of the signaled several support beacons, wherein the participant is designed to support the one or at least one of the plurality of support beacons [eg to receive at least the [temporally] first support beacon] based on the signaling information.

In embodiments, the signaling information can be information about at least one of a point in time or time interval of the transmission of the one support beacon or at least one of the plurality of support beacons, a frequency channel or frequency interval of the transmission of the one support beacon or at least one of the plurality of support beacons, and a time and / or Frequency hopping pattern based on which the support beacons are transmitted.

For example, the information about the point in time can be an absolute point in time, a relative point in time (e.g. a defined time span between the downlink data transmission and the support beacon) or information from which the absolute or relative point in time can be derived, such as a number of clock cycles an oscillator of the end point.

For example, the information about the frequency channel can be an absolute frequency channel or a relative frequency channel [for example a distance between a frequency channel of the downlink data transmission and a frequency channel of the support beacon]. For example, the support beacon can be transmitted based on the telegram splitting transmission method. When transmitting the support beacon based on the telegram splitting transmission method, data to be transmitted with the support beacon [e.g. a [coded] support beacon data packet of the physical layer] can be divided into a plurality of sub-data packets so that the plurality of sub- Data packets each have only part of the data to be transmitted, the plurality of sub-data packets not being transmitted contiguously, but rather distributed in time and / or frequency in accordance with a time and / or frequency hopping pattern.

In embodiments, the synchronization information can be information about at least one of a point in time or time interval of the transmission of a further support beacon and / or the point-to-multipoint data transmission, a frequency channel or frequency interval of the transmission of a further support beacon and / or the point-to-multipoint Data transmission, and a time and / or frequency hopping pattern based on which a further support beacon and / or the point-to-multipoint data transmission is transmitted.

In exemplary embodiments, the synchronization information can comprise a synchronization sequence for synchronizing the subscriber to the respective support beacon, the subscriber being designed to synchronize with the respective support beacon based on the synchronization sequence [e.g. based on a correlation of a received data stream with a reference sequence corresponding to the synchronization sequence in order to determine the synchronization sequence [e.g. and thus to detect the respective support beacon] in the received data stream].

In exemplary embodiments, the subscriber can be configured to receive the plurality of support beacons in order to synchronize and / or keep himself synchronized to the point-to-multipoint data transmission of the base station based on the synchronization information contained in the support beacons.

In exemplary embodiments, the multiple support beacons can be transmitted at regular intervals or on average at regular intervals, with the subscriber knowing the intervals between the transmissions of the support beacons [eg from a previous downlink transmission or an already received support beacon]. In exemplary embodiments, the multiple support beacons can be set at predetermined times [e.g. system-wide or for point-to-multipoint data transmission] and / or at predetermined time intervals and / or in predetermined frequency channels and / or in predetermined frequency channel intervals and / or in accordance with a predetermined time jump pattern and / or or transmitted according to a predetermined frequency hopping pattern.

In embodiments, at least one [e.g. each [e.g. with the exception of the last]] of the support beacons [e.g. or the synchronization information of at least one of the support beacons] information about a transmission of a subsequent [e.g. of the subsequent] support beacon, [e.g. wherein the information about the transmission is a point in time and / or time interval and / or a frequency channel and / or frequency channel interval and / or time hopping pattern and / or frequency hopping pattern], wherein the subscriber is designed to use the information on the transmission of the [e.g. each] subsequent support beacon to receive the [each] subsequent support beacon.

In embodiments, a point in time and / or a frequency channel of the transmission can be at least one [e.g. everyone [e.g. with the exception of the first]] of the support beacons from information transmitted with a preceding support beacon [e.g. CRC or support beacon counter], the subscriber being designed to determine the time and / or frequency channel of the transmission of the at least one [e.g. respective] support beacon of the [e.g. each] preceding support beacon to derive the at least one [e.g. respective] support beacon to receive.

In embodiments, points in time and / or frequency channels, or a time hop pattern and / or frequency hop pattern of the transmission of the multiple support beacons can be determined based on a calculation rule [e.g. polynomial of an LFSR or a PRBS generator], the signaling information and / or the synchronization information at least one of the support beacons has information about a current state of the calculation rule, the subscriber being designed to determine the times and / or frequency channels and / or the time jump pattern and / or frequency jump pattern of the transmission of the plurality of support beacons based on the calculation rule and the current state of the calculation rule to receive the multiple support beacons. In exemplary embodiments, the plurality of support beacons received by the subscriber can be a real subset [for example only a part] of the support beacons sent out by the base station.

In exemplary embodiments, the subscriber can be designed to send another uplink data transmission to the base station if at least one of the support beacons could not be received successfully [e.g. due to transmission errors] and to send another downlink data transmission synchronized in time with the further uplink data transmission. To receive data transmission, the further ^' downlink data transmission having further signaling information, the further signaling information signaling the transmission of at least one further [eg subsequent] support beacon, the subscriber being designed to base the at least one further [eg subsequent] support beacon on to receive the signaling information.

In embodiments, the subscriber can be configured to, if at least one of the support beacons could not be successfully received [e.g. due to transmission errors], a subsequent support beacon with increased synchronization effort [e.g. based on an extended time and / or frequency search window].

In embodiments, payload of the point-to-multipoint data transmission [e.g. with the user data to be transmitted with the point-to-multipoint data transmission] can be divided into a plurality of user data parts, at least some of the user data parts [e.g. one of the useful data portions] each together with a support beacon [e.g. in a transmission frame of a support beacon].

For example, useful data to be transmitted with the point-to-multipoint data transmission can be divided into several useful data parts and together with the support beacons [e.g. in the transmission frame of the support beacons].

For example, a data packet to be transmitted with the point-to-multipoint data transmission [e.g. the physical layer] [e.g. with the user data] are divided into several partial data packets, the partial data packets each together with one of the supporting beacons [e.g. in the transmission frame of the respective support beacon].

In exemplary embodiments, at least some of the useful data parts can be transmitted several times together with different support beacons. For example, a support beacon can have a useful data part and a duplicated useful data part or else only a single useful data part or a duplicated useful data part. In the case of the latter, a number of supporting beacons is thus at least as large as a sum of a number of useful data parts and a number of duplicated useful data parts.

In exemplary embodiments, the useful data or useful data parts can be channel-coded, so that only a part of the useful data parts is required for decoding useful data, only part of the useful data parts being transmitted together with the support beacons, or the subscriber being designed to receive the support beacons with the Set user data parts when enough user data parts have been received to decode the user data.

In embodiments, the [e.g. Synchronization information of the] support beacon or at least one of the several support beacons [e.g. the last support beacon] have information about the point-to-multipoint data transmission, the subscriber being designed to carry out the point-to-multipoint data transmission based on the information about the point-to-multipoint data transmission.

Receive multipoint data transmission.

In exemplary embodiments, the information about the point-to-multipoint data transmission can be information about at least one of a point in time or time interval of the point-to-multipoint data transmission, a frequency channel or frequency interval of the point-to-multipoint data transmission.

Data transmission, a time and / or frequency hopping pattern of point-to-multipoint data transmission.

For example, the information about the point in time can be an absolute point in time, a relative point in time (e.g. a defined time span between the support beacon and the point-to-multipoint data transmission) or information from which the absolute or relative point in time can be derived, such as a number of clock cycles of an oscillator of the endpoint.

For example, the information about the frequency channel can be an absolute frequency channel or a relative frequency channel [for example a distance between a frequency channel of the support beacon and a frequency channel of the point-to-multipoint data transmission]. For example, the point-to-multipoint data transmission can be a telegram splitting-based data transmission. In the case of telegram splitting-based data transmission, the data to be transmitted [e.g. [encoded] user data of the physical layer] are divided into a plurality of sub-data packets, so that the plurality of sub-data packets each have only part of the data to be transmitted, wherein the plurality of sub-data packets are not transmitted contiguously, but distributed in time and / or frequency in accordance with a time and / or frequency hopping pattern.

In exemplary embodiments, the support beacon or at least one of the plurality of support beacons can have point-to-multipoint data transmission assignment information, wherein the subscriber receives one of a plurality of point-to-multipoint data transmissions based on the point-to-multipoint data transmission assignment information

Base station is assigned to receive.

Further embodiments provide a base station of a communication system [wherein the communication system is in a frequency band [e.g. ISM band] communicates wirelessly which is made up of a plurality of [e.g. communication systems which are uncoordinated with one another], the base station being arranged to communicate one or a plurality of [e.g. send at least two] support beacons, [e.g. that of a [e.g. pending or planned] point-to-multipoint data transmission,] wherein the one or more support beacons [e.g. each] have synchronization information for the synchronization of uncoordinated sending subscribers of the communication system [e.g. on the respective support beacon, on a point-to-multipoint data transmission of the base station and / or on at least one further support beacon [e.g. that precedes point-to-multipoint data transmission]], the base station being adapted to handle point-to-multipoint data transmission [e.g. according to the synchronization information].

In embodiments, the base station can be designed to receive an uplink data transmission from one of the subscribers of the communication system, the uplink data transmission being uncoordinated, the base station being designed to synchronize in time with the received uplink data transmission of the subscriber a downlink To send data transmission to the subscriber, the Downiink data transmission having signaling information, the signaling information signaling the transmission of the support beacon or at least one of the plurality of support beacons. In embodiments, the signaling information can be information about at least one of a point in time or time interval of the transmission of the one support beacon or at least one of the plurality of support beacons, a frequency channel or frequency interval of the transmission of the one support beacon or at least one of the plurality of support beacons, and a time and / or Frequency hopping pattern based on which the support beacons are transmitted.

For example, the information about the frequency channel may be an absolute frequency channel or a relative frequency channel [e.g. a distance between a frequency channel of the downlink data transmission and a frequency channel of the support beacon].

For example, the support beacon can be transmitted based on the telegram splitting transmission method. When transmitting the support beacon based on the telegram splitting transmission method, data to be transmitted with the support beacon [e.g. a [coded] support beacon data packet of the physical layer] can be divided into a plurality of sub-data packets, so that the plurality of sub-data packets each have only part of the data transmitted, the plurality of sub-data packets not contiguous but in the time and / or frequency are transmitted in a distributed manner in accordance with a time and / or frequency sprung pattern.

In embodiments, the synchronization information can be information about at least one of a point in time or time interval of the transmission of a further support beacon or the

Point-to-multipoint data transmission, a frequency channel or frequency spacing of the transmission of a further support beacon or the point-to-multipoint data transmission, and a time and / or frequency hopping pattern based on the one further support beacon or the point-to-multipoint data transmission is transmitted, have. In embodiments, the synchronization information can have a synchronization sequence for synchronizing the subscriber to the respective support beacon.

In exemplary embodiments, the support beacons can each have synchronization information for synchronizing and / or maintaining the synchronization of subscribers to the point-to-multipoint data transmission.

In exemplary embodiments, the base station can be designed to transmit the plurality of support beacons at regular intervals or on average at regular intervals.

In embodiments, the base station can be designed to transmit the plurality of support beacons at predetermined times and / or with predetermined time intervals and / or in predetermined frequency channels and / or in predetermined frequency channel intervals and / or in accordance with a predetermined time hopping pattern and / or in accordance with a predetermined frequency hopping pattern .

In embodiments, the base station can be arranged to have at least one [e.g. each [e.g. with the exception of the last]] of the support beacons [e.g. or the synchronization information of at least one of the support beacons] with information about a transmission of a subsequent [e.g. of the subsequent] support beacon, [e.g. wherein the information about the transmission is a point in time and / or time interval and / or a frequency channel and / or frequency channel interval and / or time hopping pattern and / or frequency hopping pattern].

In embodiments, the base station can be designed to match the transmission distances of the support beacons to the timing accuracy [e.g. Quality of the clocks] of the subscribers who are intended to receive the support beacons [e.g. to reduce the distance if participants with a higher time difference are included].

In embodiments, the base station can be designed to derive a point in time and / or a frequency channel of the transmission of at least one [eg each [eg except the first]] of the support beacons from information transmitted with a preceding support beacon [eg CRC or support beacon counter]. In embodiments, the base station can be designed to determine times and / or frequency channels and / or a time hop pattern and / or frequency hop pattern of the transmission of the multiple support beacons based on a calculation rule [e.g. polynomial of an LFSR or a PRBS generator], the base station being designed is to provide the signaling information and / or the synchronization information of at least one of the support beacons with information about a current state of the calculation rule.

In embodiments, the base station can be configured to receive user data of the point-to-multipoint data transmission [e.g. with the user data to be transmitted with the point-to-multipoint data transmission] into a plurality of user data parts, the base station being designed to transmit at least a part of the user data parts [e.g. one of the useful data portions] each together with a support beacon [e.g. to be transmitted in a transmission frame of a support beacon.

For example, the base station can be designed to split user data to be transmitted with the point-to-multipoint data transmission into several user data parts and to use these together with the support beacons [e.g. in the transmission frame of the support beacons].

For example, the base station can be designed to transmit a data packet [e.g. the physical layer] [e.g. with the user data] into several partial data packets, and to divide the partial data packets together with one of the support beacons [e.g. in the transmission frame of the respective support beacon].

In embodiments, the base station can be designed to transmit at least a part of the useful data parts multiple times [e.g. cyclically repeated] together with different support beacons.

For example, a support beacon can have a useful data part and a duplicated useful data part or else only a single useful data part or a duplicated useful data part. In the case of the latter, a number of supporting beacons is thus at least as large as a sum of a number of useful data parts and a number of duplicated useful data parts.

In the case of exemplary embodiments, the base station can be designed to dynamically adapt the useful data portion, the adaptation being based on at least one parameter utilization of the base station [eg permitted or possible transmission time, duty cycle], utilization of the radio channel, and a number of subscribers who have received signaling information for at least one of the support beacons.

In exemplary embodiments, the base station can be designed to channel-code the useful data or useful data parts, so that only a part of the useful data parts is required for decoding useful data, the base station being designed to only transmit a part [e.g. real subset] of the useful data parts together with the supporting beacons, or the base station being designed to stop sending the supporting beacons with the useful data parts when enough useful data parts have been sent out to decode the useful data.

In embodiments, the base station can be arranged to provide the [e.g. Synchronization information of the] support beacon or at least one of the plurality of support beacons [e.g. the last support beacon] with information about the point-to-multipoint data transmission.

In embodiments, the information about the point-to-multipoint data transmission can be information about at least one of a point in time or time interval of the point-to-multipoint data transmission, a frequency channel or frequency interval of the point-to-multipoint data transmission, is a time and / or frequency hopping patterns of point-to-multipoint data transmission.

For example, the information about the point in time can be an absolute point in time, a relative point in time [e.g. a defined time span between the support beacon and the point-to-multipoint data transmission] or information from which the absolute or relative point in time can be derived, such as a number of clock cycles of an oscillator of the end point.

For example, the information about the frequency channel can be an absolute frequency channel or a relative frequency channel [for example a distance between a frequency channel of the support beacon and a frequency channel of the point-to-multipoint data transmission]. For example, the point-to-multipoint data transmission can be a telegram splitting-based data transmission. In the case of telegram splitting-based data transmission, the data to be transmitted [e.g. [encoded] user data of the physical layer] are divided into a plurality of sub-data packets, so that the plurality of sub-data packets each have only part of the data to be transmitted, wherein the plurality of sub-data packets are not transmitted contiguously, but rather distributed in the current and / or frequency according to a time and / or frequency hopping pattern.

In embodiments, the base station can be designed to provide the support beacon or at least one of the plurality of support beacons with point-to-multipoint data transmission assignment information, with groups of subscribers based on the point-to-multipoint data transmission assignment information being one of several Point-to-multipoint data transmissions are assigned to the base station for reception.

In embodiments, the base station can be designed not to assign point-to-multipoint data transmission to some of the subscribers for a period of time in which other subscribers are assigned a point-to-multipoint data transmission, the base station being designed for further support beacons to send the participants to whom no point-to-multipoint data transmission is assigned in the time segment.

Further exemplary embodiments create a method for operating an uncoordinated sending subscriber in a communication system. The method comprises a step of receiving one or more [e.g. at least two] support beacons from a base station of the communication system, [e.g. which precede a point-to-multipoint data transmission,] wherein the one or more support beacons have synchronization information. The method further comprises a step of synchronizing the subscriber to the point-to-multipoint data transmission of the base station based on the synchronization information. The method further comprises a step of receiving a point-to-multipoint data transmission from the base station based on the synchronization information.

Further exemplary embodiments create a method for operating a base station of a communication system. The method comprises a step of sending one or a plurality of [eg at least two] support beacons, [eg which precede a [eg pending or planned] point-to-multipoint data transmission,] the one or the plurality of support beacons providing synchronization information for Have synchronization of uncoordinated sending participants of the communication system. Further the method comprises a step of sending the point-to-multipoint data transmission

[e.g. according to the synchronization information].

Although some aspects have been described in connection with a device, it goes without saying that these aspects also represent a description of the corresponding method, so that a block or a component of a device is also to be understood as a corresponding method step or as a feature of a method step. Analogously to this, aspects that have been described in connection with or as a method step also represent a description of a corresponding block or details or features of a corresponding device. Some or all of the method steps can be performed by a hardware device (or using a hardware Apparatus), such as a microprocessor, a programmable computer or an electronic circuit. In some embodiments, some or more of the most important process steps can be performed by such an apparatus.

Depending on the specific implementation requirements, embodiments of the invention can be implemented in hardware or in software. The implementation can be carried out using a digital storage medium, for example a floppy disk, a DVD, a Blu-ray disk, a CD, a ROM, a PROM, an EPROM, an EEPROM or a FLASH memory, a hard disk or any other magnetic or optical memory, on which electronically readable control signals are stored, which can interact or cooperate with a programmable computer system in such a way that the respective method is carried out. Therefore, the digital storage medium can be computer readable.

Some exemplary embodiments according to the invention thus include a data carrier which has electronically readable control signals which are capable of interacting with a programmable computer system in such a way that one of the methods described herein is carried out.

In general, exemplary embodiments of the present invention can be implemented as a computer program product with a program code, the program code being effective to carry out one of the methods when the computer program product runs on a computer. The program code can, for example, also be stored on a machine-readable carrier.

Other exemplary embodiments include the computer program for performing one of the methods described herein, the computer program being stored on a machine-readable carrier.

In other words, an exemplary embodiment of the method according to the invention is thus a computer program which has a program code for performing one of the methods described herein when the computer program runs on a computer.

A further exemplary embodiment of the method according to the invention is thus a data carrier (or a digital storage medium or a computer-readable medium) on which the computer program for performing one of the methods described herein is recorded. The data carrier, the digital storage medium or the computer-readable medium are typically tangible and / or non-perishable or non-transitory.

A further exemplary embodiment of the method according to the invention is thus a data stream or a sequence of signals which represents or represents the computer program for performing one of the methods described herein. The data stream or the sequence of signals can, for example, be configured to be transferred via a data communication connection, for example via the Internet.

Another exemplary embodiment comprises a processing device, for example a computer or a programmable logic component, which is configured or adapted to carry out one of the methods described herein.

Another exemplary embodiment comprises a computer on which the computer program for performing one of the methods described herein is installed.

A further exemplary embodiment according to the invention comprises a device or a system which is designed to transmit a computer program for performing at least one of the methods described herein to a receiver. The transmission can take place electronically or optically, for example. The recipient can for example, a computer, mobile device, storage device or similar device. The device or the system can comprise, for example, a file server for transmitting the computer program to the recipient.

In some embodiments, a programmable logic device

(for example a field-programmable gate array, an FPGA) can be used to carry out some or all of the functionalities of the methods described herein. In some exemplary embodiments, a field-programmable gate array can interact with a microprocessor in order to carry out one of the methods described herein. In general, in some exemplary embodiments, the methods are performed by any hardware device. This can be hardware that can be used universally, such as a computer processor (CPU), or hardware specific to the method, such as an ASIC, for example.

The devices described herein can be implemented, for example, using a hardware apparatus, or using a computer, or using a combination of a hardware apparatus and a computer.

The devices described herein, or any components of the devices described herein, can be implemented at least partially in hardware and / or in software (computer program).

For example, the methods described herein can be implemented using hardware apparatus, or using a computer, or using a combination of hardware apparatus and a computer.

The methods described herein, or any components of the methods described herein, can be carried out at least in part by hardware and / or by software.

The embodiments described above are merely illustrative of the principles of the present invention. It is to be understood that modifications and variations of the arrangements and details described herein will be apparent to other skilled persons. It is therefore intended that the invention be limited only by the scope of protection of the following patent claims and not by the specific details presented herein with reference to the description and explanation of the exemplary embodiments. PAGE INTENTIONALLY LEFT BLANK

Bibliography [1] G. Kilian, M. Breiiing, H. H. Petkov, H. Lieske, F. Beer, J. Robert, and A. Heuberger,

“Increasing Transmission Reiiability for Telemetry Systems Using Telegram Splitting,” IEEE Transactions on Communications, vol. 63, no. 3, pp. 949-961, Mar. 2015.

[2] DE 10 2011 082 098 B1

[3] DE 10 2017 206 236 A1

[4] ETSI TS 103 357 Standard v1.1.1 [5] DE 102017204 186 A1

Claims

1. Subscriber (106_1) of an uncoordinated communication system (100), the communication system (100) communicating wirelessly in a frequency band which is used by a plurality of mutually uncoordinated communication systems (101, 102), the subscriber (106_1) being configured, in order to receive and decode a first data packet (130_1) of a plurality of data packets (130__1-130J) of a data transmission (124), the plurality of data packets (130_1 -130J) being multiple transmissions of the same data packet, the subscriber (106_1) being configured is to, if the subscriber (106_1) satisfies a receive criterion, ^'to receive (124), wherein the subscriber (106_1) ^configured' no further data packet of the plurality of data packets (130_1-130J) of the data transmission is to, in case the the Participant (106_1) the

Receipt criterion not met, at least one second data packet (130_2-130J) of the plurality of data packets (130_1-130j) of the data transmission to be received.

2. Subscriber (106_1) according to claim 1, wherein the data transmission (124) is a downlink data transmission.

3. Subscriber (106_1) according to claim 1, wherein the data transmission (124) is a point-to-multipoint data transmission.

4. Participant (106_1) according to one of claims 1 to 3, wherein the participant (106_1) is configured to determine whether the participant (106_1) meets the reception criterion.

5. Participant (106_1) according to claim 4, wherein the reception criterion is at least one of a successful decoding of the first data packet (130_1), a signal-to-noise ratio of a received signal of the first data packet

(130_1) or a previous data packet, a received field strength of a received signal of the first data packet (130_1) or a previous data packet. a successful redundancy check of the first data packet (130_1).

6. Subscriber (106_1) according to one of claims 1 to 3, wherein a downlink data transmission preceding the data transmission (124) contains information about whether the subscriber (106_1) meets the reception criterion.

7. Subscriber (106_1) according to one of claims 1 to 6, wherein the plurality of data packets (13CM-130J) are symbolically identical.

8. Subscriber (106_1) according to one of claims 1 to 7, wherein the plurality of data packets (13CM-130J) have the same user data, and / or wherein the plurality of data packets (130_1 -130J) have the same error protection data or different error protection data.

9. Subscriber (106_1) according to one of claims 1 to 8, wherein at least one first data packet (130_1) of the plurality of data packets (130_1 -130J) has a higher code rate and / or data rate than the other data packets (130_2-130J) of the plurality of data packets (130_1-130J).

10. Participant (106_1) according to one of claims 1 to 9 wherein the subscriber (106_1) is configured to switch from a normal operating mode to an energy-saving mode if the subscriber (106_1) meets the reception criterion.

11. Subscriber (106_1) according to one of claims 1 to 10, wherein the plurality of data packets (13Q_1-130J) are each provided with error protection data, wherein the subscriber (106_1) is configured to, if the subscriber (106_1) does not meet the reception criterion fulfilled and decoding of the first data packet (130_1) was unsuccessful, the first data packet (130_1) and the at least one second (130_2-130J) data packet to be combined in order to achieve through the combination of the first data packet (130_1) and the at least one second data packet (130_2-130J) to achieve a higher code gain during decoding.

12. Subscriber (106_1) according to one of claims 3 to 11, wherein the subscriber (106_1) is configured to synchronize in time with a sent uplink data transmission (120) to a base station (104) of the communication system (100) a downlink data transmission (122) from the base station (104), the downlink data transmission (122) having signaling information, the subscriber (106_1) being configured to, based on the signaling information, at least the first data packet of the point-to-multipoint data transmission (124) of the base station (104).

13. Subscriber (106_1) according to claim 12, wherein the signaling information includes information about a point in time of the point-to-multipoint data transmission (124).

14. Subscriber (106_1) according to one of claims 12 to 13, wherein the signaling information further comprises information about a frequency channel of the point-to-multipoint data transmission (124).

15. Subscriber (106_1) according to one of claims 1 to 14, wherein the subscriber (106_1) is a telegram splitting-based subscriber, wherein a data packet of the plurality of data packets (130_1-130_j) is a sub-data packet of a plurality of sub- Data packets which each have a part of the data transmission (124) and which are each shorter than the data transmission (124) and which are transmitted in a distributed manner according to a time and / or frequency hopping pattern, the other data packets (130_2-130 J) being the A plurality of data packets (130_1-130J) are retransmissions of the same sub-data packet.

16. Subscriber (106_1) according to one of claims 1 to 15, wherein a data packet (130_1) of the plurality of data packets (130_1 -130J) is a radio burst like, of the ETSI TS 103 357 standard, and wherein the other data packets (130_2- 130 J) of the plurality of data packets (130_1-130J) are retransmissions of the same radio burst.

17. Participant (106_1) according to one of claims 1 to 16, wherein the participant (106_1) is a sensor node or actuator node.

18. Subscriber (106_1) according to one of claims 1 to 17, wherein the subscriber (106_1) is battery-operated, and / or wherein the subscriber (106_1) has an energy harvesting element for generating electrical energy.

19. Communication system (100) having the following features: at least one participant (106_1) according to one of claims 1 to 18, and a base station (104) which is configured to send out the plurality of data packets (13CM-130J) of the data transmission (124).

20. Subscriber (106_1) of an uncoordinated communication system (100), the communication system (100) communicating wirelessly in a frequency band which is used by a plurality of mutually uncoordinated communication systems (101, 102), the subscriber (106_1) being configured, in order to be synchronized in time with a transmitted uplink data transmission (120) to the base station (104) of the

Communication system (100) to receive a downlink data transmission (122) from the base station (104), the downlink data transmission (122) having a first signaling information and a second signaling information, the first signaling information being a first point-to-multipoint data transmission (124_1) signals, and wherein the second signaling information signals a second point-to-multipoint data transmission (124_2), wherein the subscriber (106_1) is configured, based on the downlink data transmission (122) or a previous downlink data transmission, or to determine a reception quality of a previous point-to-multipoint data transmission, the subscriber (106_1) being configured to select one of the first point-to-multipoint data transmission based on the first signaling information and the second as a function of the determined reception quality Point-to-multipoint data transmission based on d he first receive signaling information.

21. Subscriber (106_1) according to claim 20, wherein the subscriber (106_1) is configured to, if the determined reception quality meets a first reception quality criterion, the first point-to-multipoint To receive data transmission (124_1) based on the first signaling information, the subscriber (106_1) being configured to carry out the second point-to-multipoint data transmission if the received quality of reception does not meet the first quality of reception criterion or if the quality of reception determined meets a second quality of reception criterion (124_2) based on the second signaling information, wherein the first reception quality criterion and the second reception quality criterion are different.

22. Subscriber (106_1) according to claim 21, wherein the first reception quality criterion indicates that the reception quality is greater than or equal to a reception quality threshold or lies within a first reception quality range.

23. Subscriber (106_1) according to claim 22, ^" wherein the second reception quality criterion indicates that the reception quality is less than the reception quality threshold or lies within a second reception quality range, the first reception quality range and the second reception quality range being different.

24. Subscriber (106_1) according to one of Claims 21 to 23, wherein the first reception quality criterion is specified or wherein the downlink data transmission (122) has information about the first reception quality criterion.

25. Participant (106_1) according to claim 24, wherein the second reception quality criterion is specified or wherein the downlink data transmission (122) has information about the second reception quality criterion.

26. Subscriber (106_1) according to one of claims 20 to 25, wherein the first point-to-multipoint data transmission (124_1) and the second

Point-to-multipoint data transmission (124_2) with regard to at least one of transmission times,

Differentiate between transmission frequencies, frequency and / or time hopping patterns used.

27. Subscriber (106_1) according to one of claims 20 to 26, wherein the first point-to-multipoint data transmission (124_1) and the second point-to-multipoint data transmission (124_2) have different data rates.

28. Subscriber (106_1) according to one of claims 20 to 27, wherein the first point-to-multipoint data transmission (124_1) and the second point-to-multipoint data transmission (124_2) are coded differently.

29. Subscriber (106_1) according to one of claims 20 to 28, wherein the first point-to-multipoint data transmission (124_1) and the second point-to-multipoint data transmission (124_2) have the same useful data.

30. Subscriber (106_1) according to one of claims 20 to 29, wherein the first point-to-multipoint data transmission (124_1) has a plurality of first sub-data packets which are in the time and / or frequency corresponding to a time and / or frequency hopping patterns are transmitted in a distributed manner, and / or wherein the second point-to-multipoint data transmission (124_2) has a plurality of second sub-data packets which are transmitted in a distributed manner in the time and / or frequency in accordance with a time and / or frequency hopping pattern .

31. Subscriber (106_1) according to claim 30, wherein the plurality of first sub-data packets and / or the plurality of sub-data packets are radio bursts of the ETSI TS 103 357 standard.

32. Subscriber (106_1) according to one of claims 20 to 31, wherein the subscriber (106_1) is a sensor node or actuator node.

33. Subscriber (106_1) according to one of claims 20 to 32, wherein the subscriber (106_1) is battery-operated, and / or wherein the subscriber (106_1) has an energy harvesting element for generating electrical energy.

34. Base station (104) of an uncoordinated communication system (100), the communication system (100) communicating wirelessly in a frequency band that is used by a plurality of mutually uncoordinated communication systems, the base station (104) being configured to transmit uplink data (120) from a subscriber (106_1) of the communication system (100), the uplink data transmission (120) being uncoordinated, the base station (104) being configured to synchronize in time with the received uplink data transmission (120) of the Subscriber (106_1) to send a downlink data transmission (122) to the subscriber (106_1), the downlink data transmission (122) having first signaling information and second signaling information, the first signaling information being a subsequent first point-to-multipoint Data transmission (124_1) signaled, and the second signaling information ion signals a subsequent second point-to-multipoint data transmission (124_2), wherein the base station (104) is configured to transmit the first point-to-multipoint data transmission (124_1) according to the first signaling information and to transmit the second point-to-multipoint data transmission (124_2) according to the second signaling information, wherein the second point-to-multipoint data transmission (124_2) has a lower code rate and / or data rate than the first point-to-multipoint data transmission (124_1) in comparison with a probability of passage of the second point-to-multipoint data transmission (124_2) the first point-to-multipoint data transmission (124_1) in relation to subscribers (106_1-106_n) of the communication system (100) who do not meet a reception quality criterion.

35. Base station (104) according to claim 34, wherein the reception quality criterion indicates that a reception quality of the respective subscriber (106_1-106_n) of the communication system (100) is greater than or equal to a reception quality threshold or lies within a first reception quality range.

36. Base station (104) according to one of claims 34 to 35, wherein the base station (104) is configured to provide the downlink data transmission (122) with information about the reception quality criterion.

37. Base station (104) according to claim 36, wherein the reception quality criterion is a first reception quality criterion, wherein the base station (104) is configured to provide the downlink data transmission (122) with information about a second reception quality criterion, the second reception quality criterion indicating that a reception quality of the respective subscriber (106_1-106_n) of the communication system (100) is less than the reception quality threshold or lies within a second reception quality range, the first reception quality range and the second reception quality range being different.

38. Base station (104) according to one of claims 34 to 37, wherein the first point-to-multipoint data transmission (124_1) and the second point-to-multipoint data transmission (124_2) have the same useful data.

39. Base station (104) according to one of claims 34 to 38, wherein the first point-to-multipoint data transmission (124_1) and the second point-to-multipoint data transmission (124_2) differ with regard to at least one of transmission times,

Differentiate transmission frequencies and frequency and / or time hopping patterns used.

40. Base station (104) according to one of claims 34 to 38, wherein the first point-to-multipoint data transmission (124_1) has a plurality of first sub-data packets which are in the time and / or frequency corresponding to a time and / or frequency hopping patterns are transmitted in a distributed manner, and / or wherein the second point-to-multipoint data transmission (124_2) has a plurality of second sub-data packets which are transmitted in a distributed manner in the time and / or frequency in accordance with a time and / or frequency hopping pattern .

41. Base station (104) according to claim 40, wherein the plurality of first sub-data packets and / or the plurality of sub-data packets are radio bursts according to the ETSI TS 103 357 standard.

42. Communication system with the following features: at least one subscriber (106_1) according to one of claims 18 to 31, and a base station (104) according to one of claims 32 to 39.

43. base station (104) of an uncoordinated communication system (100), wherein the communication system (100) communicates wirelessly in a frequency band which is used by a plurality of mutually uncoordinated communication systems (101, 102), the base station (104) being configured to initiate an uplink data transmission (120) from a subscriber (106_1) of the Communication system (100), wherein the uplink data transmission (120) is uncoordinated, wherein the uplink data transmission (120) has information about a reception quality of the subscriber (106_1) or wherein the base station (104) is configured to be based on of the uplink data transmission (120) to estimate a reception quality of the subscriber (106_1), the base station (104) being configured to synchronize in time with the received uplink data transmission (120) of the subscriber (106_1) a downlink data transmission (122) to the subscriber (106_1), the base station (104) being configured to control the downlink data transmission (122) in A depending on the reception quality of the subscriber (106_1) with a first signaling information or a second signaling information, wherein the first signaling information signals a subsequent first point-to-multipoint data transmission (124_1), and the second signaling information a subsequent second point-to -Multipoint data transmission (124_2), wherein the base station (104) is configured to send the first point-to-multipoint data transmission (124_1) according to the first signaling information and to send the second point-to-multipoint data transmission (124_2 ) to send according to the second signaling information.

44. Base station (104) according to claim 43, wherein the base station (104) is configured to provide the downlink data transmission (122) with the first signaling information if the reception quality of the subscriber (106_1) meets a first reception quality criterion, wherein the base station (104) is configured to provide the downlink data transmission (122) with the second signaling information if the reception quality of the subscriber (106_1) does not meet the first reception quality criterion or the reception quality of the subscriber (106_1) meets a second reception quality criterion .

45. Base station (104) according to claim 44, wherein the first reception quality criterion indicates that the reception quality is greater than or equal to a reception quality threshold or lies within a first reception quality range.

46. Base station (104) according to claim 45, wherein the second reception quality criterion indicates that the reception quality is less than the reception quality threshold or lies within a second reception quality range, the first reception quality range and the second reception quality range being different.

47. Base station (104) according to one of claims 44 to 46, wherein the first reception quality criterion is predetermined, or wherein the base station (104) is configured to the first

Dynamically adapt the reception quality criterion.

48. Base station (104) according to claim 47, ^" wherein the second reception quality criterion is predetermined, or wherein the base station (104) is configured to the second

Dynamically adapt the reception quality criterion.

49. Base station (104) according to one of claims 43 to 48, wherein the first point-to-multipoint data transmission (124J) and the second

50. Base station (104) according to one of claims 43 to 49, wherein the first point-to-point data transmission (124_1) and the second point-to-multipoint data transmission (124_2) have different data rates.

51. Base station (104) according to one of claims 43 to 50, wherein the first point-to-multipoint data transmission (124_1) and the second point-to-multipoint data transmission (124_2) are coded differently.

52. Base station (104) according to one of claims 43 to 51, wherein the first point-to-multipoint data transmission (124_1) and the second point-to-multipoint data transmission (124_2) have the same useful data.

53. Base station (104) according to one of claims 43 to 52, wherein the first point-to-multipoint data transmission (124_1) has a plurality of first sub-data packets which are in time and / or frequency corresponding to a time and / or frequency hopping patterns are transmitted in a distributed manner, and / or wherein the second point-to-multipoint data transmission (124J2) comprises a plurality of second sub-data packets which are transmitted in a time and / or frequency distributed according to a time and / or frequency hopping pattern .

54. Base station (104) according to claim 53, wherein the plurality of first sub-data packets and / or the plurality of sub-data packets are radio bursts like the ETSI TS 103357 standard.

55. Communication system (100), having the following features: a base station (104) according to one of claims 43 to 54, and at least one subscriber (106_1), wherein the at least one subscriber (106_1) is configured to be time-synchronized with the transmitted uplink Data transmission (120) to the base station (104) of the communication system (100) to receive the downlink data transmission (122) from the base station (104), the downlink data transmission (122) having one of the first signaling information and the second signaling information is provided, wherein the first signaling information signals the first point-to-multipoint data transmission (124_1), and wherein the second signaling information signals the second point-to-multipoint data transmission (124_2), wherein the at least one participant (106_1) is configured , based on the signaling information with which the downlink data transmission (122) is provided, the respective point-z u receive multipoint data transmission.

56. Base station (104) of an uncoordinated communication system (100), the communication system (100) communicating wirelessly in a frequency band that is used by a plurality of mutually uncoordinated communication systems, the base station (104) being configured to have a first point to multipoint data transmission (124_1), wherein the base station (104) is configured to cancel or pause the transmission of the first point-to-multipoint data transmission (124_1) if at the time of the transmission of the first point-to Multipoint data transmission (124_1) at least one second data transmission (126), which has a higher priority than the first point-to-multipoint data transmission (124_1), is pending transmission, and wherein the base station (104) is configured to transmit the at least one second data transmission (126).

57. Base station (104) according to claim 56, wherein the at least one second data transmission (126) is a second point-to-point

Multipoint data transmission (124_2), and / or wherein the at least one second data transmission (126) is one or more point-to-point

Point data transfers are.

58. Base station (104) according to claim 56, wherein the base station (104) is configured to resume the transmission of the first point-to-multipoint data transmission (124_1) after the transmission of the at least one second data transmission (126), if one is used The available duty cycle of the base station (104) is sufficient for resuming the first point-to-multipoint data transmission (124_1).

59. Base station (104) of an uncoordinated communication system (100), the communication system (100) communicating wirelessly in a frequency band which is used by a plurality of mutually uncoordinated communication systems (101, 102), the base station (104) being configured, to transmit a second point-to-multipoint data transmission (124_2) within a transmission interval, wherein the base station (104) is further configured to transmit at least part of a first point-to-multipoint data transmission (124_1) within the transmission interval if within the transmission interval a duty cycle of the base station (104) is sufficient for the transmission of the at least part of the first point-to-multipoint data transmission (124_1).

60. base station (104) according to claim 59, wherein the second point-to-multipoint data transmission (124_2) has a higher priority than the first point-to-multipoint data transmission (124_1).

61. Base station (104) according to one of claims 56 to 60, wherein the first point-to-multipoint data transmission (124_1) has a plurality of first sub-data packets which are in the time and / or frequency corresponding to a time and / or frequency hopping patterns are transmitted in a distributed manner, and / or wherein the second point-to-multipoint data transmission (124_2) has a plurality of second sub-data packets which are transmitted in a distributed manner in the time and / or frequency in accordance with a time and / or frequency hopping pattern .

62. Base station (104) according to claim 61, wherein the plurality of first sub-data packets and / or the plurality of sub-data packets are radio bursts like the ETS / TS 103 357 standard.

63. Communication system (100), having the following features: a base station (104) according to one of claims 56 to 62, and at least one subscriber (106_1), wherein the at least one subscriber (106_1) is configured to use the first point-to-point

Multipoint data transmission (124_1) and / or the second point-to-multipoint

Receive data transmission (124_2).

64. Base station of an uncoordinated communication system (100), wherein the communication system (100) communicates wirelessly in a frequency band which is used by a plurality of mutually uncoordinated communication systems (101, 102), wherein the base station (104) is configured around a point -to-multipoint data transmission (124) to be divided into at least two point-to-multipoint partial data transmissions (125_1, 125_2), wherein the base station (104) is configured _» to have at least a first point-to-point

Multipoint partial data transmission (125_) of the at least two point-to-multipoint

To transmit partial data transmissions (125_1, 125_2) to a plurality of subscribers (106__1-106_n) of the communication system (100) _» where the base station (104) is configured _» to receive acknowledgments from at least some of the plurality of subscribers (106_1-106_n) to receive _» wherein the receipts (126) confirm successful receipt of the at least one first point-to-multipoint partial data transmission (125_1) _» wherein the base station (104) is configured _» to based on a number of received receipts (126) to determine a measure of success _» where the base station (104) is configured _» by _» provided the measure of success is a

Success criterion fulfilled _» to at least one second point-to-multipoint partial data transmission (125_2) of the at least two point-to-multipoint partial

To transmit data transmissions (125_1, 125_2) to the plurality of participants (106_1-106_n) of the communication system (100).

65. Base station (104) according to claim 64 _» wherein the base station (104) is configured to _» if the measure of success is the

Success criterion not met, to cancel the transmission of the point-to-multipoint data transmission (124) or to send out the first point-to-multipoint partial data transmission (125_1) again.

To receive a base station (104) according to any one of claims 64 to 65 _»and a plurality of subscribers (106_1-106_n) which are configured _to" the point-to-multipoint data transmission (124): 66. Communication System _"having the following features .

67. A method (200) for receiving a data transmission in an uncoordinated communication system _"wherein the communication system in a frequency band communicates wirelessly, which is used by a plurality of mutually uncoordinated communication systems, the method comprising:

Receiving (202) and decoding at least one first data packet of a plurality of data packets of the data transmission, the plurality of data packets being multiple transmissions of the same data packet,

Receiving (204), if a reception criterion is met, not to receive any further data packets of the plurality of data packets of the data transmission, and

Receiving (206), if the receiving criterion is met, at least one further data packet of the plurality of data packets of the data transmission.

68. A method (210) for receiving a point-to-multipoint data transmission in an uncoordinated communication system, the communication system communicating wirelessly in a frequency band that is used by a plurality of mutually uncoordinated communication systems, the method comprising:

Sending (212) an uplink data transmission;

Receiving (214), synchronized in time with the transmitted uplink data transmission, of a downlink data transmission, the downlink data transmission having first signaling information and second signaling information, the first signaling information signaling a first point-to-multipoint data transmission, and wherein the second signaling information signals a second point-to-multipoint data transmission,

Determining (216) a reception quality based on the downlink data transmission or a previous downlink data transmission or a previous one

Point-to-multipoint data transmission, and

Receiving (218), depending on the determined reception quality, one of the first point-to-multipoint data transmission based on the first signaling information, and the second point-to-multipoint data transmission based on the first signaling information.

69, method (220) for sending point-to-multipoint data transmissions in an uncoordinated communication system, the communication system communicating wirelessly in a frequency band that is used by a plurality of mutually uncoordinated communication systems, the method comprising:

Receiving (222) an uplink data transmission, the uplink data transmission being uncoordinated,

Sending (224), synchronized in time with the received uplink data transmission, a downlink data transmission, the downlink data transmission having first signaling information and second signaling information, the first signaling information signaling a subsequent first point-to-multipoint data transmission, and wherein the second signaling information signals a subsequent second point-to-multipoint data transmission,

Sending (226) the first point-to-multipoint data transmission in accordance with the first signaling information, and

Sending (228) the second point-to-multipoint data transmission in accordance with the second signaling information, the second point-to-multipoint data transmission having a lower code rate and / or data rate than the first point-to-multipoint data transmission in order to achieve a probability of getting through the second point-to-multipoint

To increase data transmission compared to the first point-to-multipoint data transmission.

70. A method (230) for sending point-to-multipoint data transmissions in an uncoordinated communication system, the communication system communicating wirelessly in a frequency band which is used by a plurality of communication systems that are uncoordinated with one another, the method comprising:

Receiving (232) an uplink data transmission, the uplink data transmission being uncoordinated, Extracting (234) information about a reception quality from the uplink data transmission or estimating a reception quality based on the uplink data transmission,

Sending (236), synchronized in time with the received uplink data transmission, a downlink data transmission, the downlink data transmission being provided with a first signaling information item or a second signaling information item depending on the reception quality, the first signaling information item being a _. signals subsequent first point-to-multipoint data transmission, and wherein the second signaling information signals a subsequent second point-to-multipoint data transmission,

Sending (238) the first point-to-multipoint data transmission in accordance with the first signaling information, and

Sending (240) the second point-to-multipoint data transmission in accordance with the second signaling information.

71. A method (250) for transmitting point-to-multipoint data transmissions in an uncoordinated communication system, the communication system communicating wirelessly in a frequency band which is used by a plurality of mutually uncoordinated communication systems, the method comprising:

Transmitting (252) a first point-to-multipoint data transmission,

Abort (254) or pause the transmission of the first point-to-multipoint data transmission if at least one second data transmission which has a higher priority than the first point-to-multipoint at the time of the transmission of the first point-to-multipoint data transmission -Data transfer, pending transfer, and

Transmitting (256) the second data transmission.

72. A method (260) for transmitting point-to-multipoint data transmissions in an uncoordinated communication system, the communication system wirelessly communicating in a frequency band which is of a plurality of communication systems that are not coordinated with one another are used, the method comprising:

Transmitting (262) a second point-to-multipoint data transmission within a transmission interval,

Transmission (264) within the transmission interval of at least part of a first point-to-multipoint data transmission, provided that a duty cycle of the base station is sufficient for the transmission of the at least part of the first point-to-multipoint data transmission within the transmission interval.

73. A method (270) for transmitting a point-to-multipoint data transmission in an uncoordinated communication system, the communication system communicating wirelessly in a frequency band that is used by a plurality of communication systems that are uncoordinated with one another, the method comprising:

Splitting (272) the point-to-multipoint data transmission into at least two point-to-multipoint partial data transmissions,

Transmitting (274) at least one first point-to-multipoint partial data transmission of the at least two point-to-multipoint partial data transmissions to a plurality of users of the communication system,

Receiving (276) acknowledgments of receipt from at least some of the plurality of participants, the acknowledgments of receipt confirming successful receipt of the at least one first point-to-multipoint partial data transmission,

Determining (278), based on a number of receipts received, a measure of success, and

If the measure of success meets a success criterion, transmitting (280) at least one second point-to-multipoint partial data transmission of the at least two point-to-multipoint partial data transmissions to the plurality of subscribers in the communication system.

74. Computer program for carrying out the method according to one of claims 67 to 73, when the computer program runs on a computer, microprocessor or software-based receiver.