CN117897994A

CN117897994A - Method for operating a node in a radio network

Info

Publication number: CN117897994A
Application number: CN202280058725.9A
Authority: CN
Inventors: H·派特可夫; T·考伯特
Original assignee: Diehl Metering Systems GmbH
Current assignee: Diehl Metering Systems GmbH
Priority date: 2021-09-03
Filing date: 2022-08-19
Publication date: 2024-04-16

Abstract

The invention relates to a method for operating a node (1), preferably an end node, in a radio network (100) comprising at least one node (1) and at least one base station (10), said node (1) comprising a transmitter and/or a receiver, preferably a transceiver (5), a battery (6) and an energy buffer (7), for transmitting and/or receiving radio messages in the form of Data Packets (DP) in the uplink and/or in the downlink, each Data Packet (DP) being divided into a plurality of individual sub-data packets, preferably sub-data packets involving different frames of Data Packets (DP), in particular sub-data packets (C1 to C1+m or E1 to E1+n) involving Data Packets (DP), and each sub-data packet being transmitted and/or received successively in time intervals (T_RB (s)) preferably in a narrowband or ultra-narrowband as radio burst (FB), preferably by different frequencies, in time transmission intervals (T_RB (s)), and further preferably being provided with at least two bursts (Sy) and one burst (CL) of at least one burst (C1 to C1+m) or E1 to E1+n) being set up and at a burst (CL) of at least two bursts (62), respectively, and at least one burst (CL) is set up to a burst (CL) of a burst (62) between two (CL) and a burst (62) of one burst (62) of burst (62) and one burst (62) of burst (62) being set up, respectively, and one burst (62) being set up, radio pulses (FB) within cl+x) are successively transmitted and/or received at time transmission intervals (t_rb (s)) respectively, and the number of radio pulses (FB) in the corresponding radio pulse cluster (CL 1, cl+x) is less than the symbol rate of 2380371Sym/s with reference to 2380371 symbol according to the number of radio pulses (FB) and/or the time transmission intervals (t_rb (s)) respectively predetermined by ETSI TS 103 357v1.1.1.1 (2018-06).

Description

Method for operating a node in a radio network

Technical Field

The present invention relates to a method for operating a node in a radio network according to the preamble of claim 1. The invention also relates to a node of a radio network according to the preamble of claim 24.

Background

The invention relates to a method for operating a node of energy self-sufficient operation in a radio network, preferably a radio network of the type described in ETSI TS103 357 v1.1.1 (2018-06). This relates to radio networks using unlicensed bands. In such a network, on the one hand, a large number of nodes, in particular end nodes, are provided, which communicate via radio with the base station only in the uplink or in both the uplink and the downlink. A node may relate to a sensor device for recording any type of data, an actuator device for performing a specific operation or measure, or a combination of a sensor device and an actuator device. Such nodes are operated by means of an energy supply device in the form of a self-contained, i.e. self-sufficient, uncharged, permanently wired long-life battery, which has a limited service life which depends on the individual energy consumption of the node and is not rechargeable, but must be replaced at the end of the service life. Normally, a "field" service life of at least ten years can be achieved with such a battery until replacement is required.

In order to buffer the energy from the battery, an energy buffer is used in the node from which an energy consumer (e.g. a receiver or transceiver of the node) extracts the required energy. In two-way communication, for example, a telegram of a node is first transmitted in the uplink and then transmitted from the base station to the node in the downlink. The telegrams or data packets are "split", i.e. broken up into individual sub-packets, and these are subsequently received in the downlink or transmitted in the uplink as "radio pulses" or "radio packets" at time intervals t_rb(s). The radio pulse has a length of about 12 to 22ms in the downlink and about 15ms in the uplink. According to ETSI TS103 357 v1.1.1 (2018-06), the time transmission interval t_rb(s) of adjacent radio pulses averages about 230ms in the downlink and about 150ms in the uplink. The sub-packets may be transmitted in a unique frequency channel or alternatively transmitted individually over different frequencies or frequency channels. In the downlink, it is proposed according to ETSI TS103 357 v1.1.1 (2018-06) to combine radio pulses into blocks of an extension frame including a plurality of radio pulses and to receive the radio pulses with an intermittent Δt_dn respectively set between the blocks. Further, an interval Δt_tsi between the core frame and the extension frame is predetermined in the standard. The pause deltat_dn (block pause) and deltat_tsi (frame pause) can be up to 7168 symbols or 65532 symbols at maximum. Corresponds to 3.011s for Δt_dn and 27.53s for Δt_tsi.

Disclosure of Invention

The aim of the invention is to reduce the production costs of a node while maintaining its operational capacity.

The above-mentioned task is solved by a method according to claim 1 and a node according to claim 24. Advantageous embodiments of the method according to the invention are claimed in the dependent claims.

According to the invention, it is provided that at least two, preferably a plurality of pauses are provided, said respective pauses being provided between two adjacent radio pulses and the symbol rate with reference to 2380371Sym/s being respectively longer than 7168 symbols. The pause is a time window in which the transmission of radio pulses is interrupted or stopped. Thus, the pause is not a pause between two frames (especially a core frame and an extension frame), which is defined as Δt_tsi in ETSI TS103 357 v1.1.1 (2018-06), and is also not a transmission interval of two adjacent radio pulses, which is defined as radio pulse time t_rb(s) in ETSI TS103 357 v1.1.1 (2018-06).

Alternatively or additionally, it is provided according to the invention that the radio pulses are combined into radio pulse clusters, the radio pulses within which are each transmitted and/or received successively at time transmission intervals, and that at least one radio pulse cluster in the uplink comprises fewer than 24 radio pulses and/or at least two radio pulse clusters in the downlink comprises fewer than 18 radio pulses.

Alternatively or additionally, it is provided according to the invention that the symbol rate of the time transmission interval (t_rb (s)) with reference to 2380371Sym/s is greater than 655 symbols.

When a radio pulse is received or transmitted, energy is extracted from the energy buffer, respectively, which causes the voltage of the energy buffer to drop briefly until the energy buffer is recharged from the battery. By means of the measures mentioned above, the energy buffer can be effectively protected in respect of its discharge characteristics, respectively, so that particularly inexpensive energy buffers can be used. Thus, the manufacturing cost can be effectively reduced without limiting the working capacity.

The respective pauses can be arranged in particular between two adjacent radio pulses of a frame, preferably a core frame and/or an extension frame.

In particular, the radio pulse clusters can also be formed in such a way that the blocks of individual radio pulses are divided into at least two radio pulse clusters separated by the gap. Block pauses may be maintained between blocks.

Preferably the pauses are arranged between two adjacent radio pulses of a frame, the two adjacent radio pulses belonging to different radio pulse clusters.

The clusters of radio pulses separated by respective intervals may each comprise the same number of radio pulses.

Preferably, in order to alleviate the load of the energy buffer for generating the number of radio pulses in the corresponding radio pulse cluster, the respective predetermined number of radio pulses per block may be divided by the ETSI TS 103 357 v1.1.1 (2018-06).

Preferably no pauses may be provided in the uplink in the first part of the data packet or the first part of the frame of the data packet and pauses may be provided in the second part of the data packet or the second part of the frame of the data packet or pauses of a shorter length may be provided in the first part of the data packet or the first part of the frame of the data packet than in the second part of the data packet or the second part of the frame of the data packet.

For example, the core frame may not contain an intermittent, and the extension frame may contain an intermittent, or the core frame and the extension frame may each contain an intermittent, wherein the intermittent of the core frame may be determined to be smaller than the intermittent of the extension frame, respectively.

Conveniently, the location or distribution of the respective pauses within the data packet or frame and/or the length of the respective pauses and/or the number of radio pulses per radio pulse cluster and/or the number of symbols per radio pulse, respectively, may be determined such that the coherence time is maintained.

Thus, the radio pulses of at least one radio pulse cluster may be within the coherence time, preferably the radio pulses of at least two radio pulse clusters in the uplink may be within the coherence time and/or the radio pulse clusters in the coherence time in the first part of the transmission of the data packet may be smaller than in the second part of the transmission.

Advantageously, the accuracy of the quartz of the node and/or the accuracy of the quartz of the base station are taken into account together when determining the length of the pauses.

Furthermore, the radio pulses of at least one radio pulse cluster may be within the coherence time, preferably the radio pulses of at least two radio pulse clusters in the uplink may be within the coherence time, and/or the radio pulse clusters within the coherence time in a first or earlier part of the transmission of the data packet may be smaller than in a second or later part of the transmission.

Preferably, at least one frequency and/or time readjustment, preferably a plurality of successive frequency and/or time readjustments, can be performed upon reception of the radio pulse. In particular, the following adjustment measures can be taken to reduce the load on the energy buffer:

the number of symbols per radio pulse (FB) is smaller before the first frequency and/or time retune than after the retune, e.g. 24 symbols instead of 36 symbols, and/or

Before the first frequency and/or time readjustment, the length of the respective pause (DeltaT_add) is short after readjustment, and/or

The average energy consumption per unit time is high after the readjustment before the first frequency and/or time readjustment, and/or

The average current drawn from the energy buffer (7) is higher before the first frequency and/or time readjustment than after the readjustment, and/or

Before the first frequency and/or time readjustment, the length of the time transmission interval (T_RB (s)) is shorter than after the readjustment, and/or

The number of radio pulses per radio pulse cluster (CL 1, CL + x) is smaller before the first frequency and/or time retune than after the retune.

Thus, frequency and/or time readjustment may result in an extension of the pauses (Δt_add) and/or block pauses (Δt_dn) and/or time transmission intervals (t_rb (s)). Thus, the determination of the burst length of the core frame may be performed taking into account the quartz precision of the node, and/or the determination of the burst length of the extension frame may be performed taking into account the quartz precision of the base station. For example, the radio pulses of the core frame or the pauses therein may be divided in the uplink and/or downlink first of all, taking into account the coherence time, based on the coherence time in relation to the quartz used for the time measurement in the node. For the radio pulses of the extension frames or for the blocks containing the radio pulses, frequency and/or time readjustment, i.e. resynchronization, can be performed, and then the pauses or additional pauses between clusters of the extension frames can be increased taking into account the coherence time. Based on this, the core frames may be sent unchanged or at least in shorter pauses, while larger pauses may be set in the extended frames based on the increased coherence time in the extended frames.

It has been shown to be particularly advantageous for the energy buffer to form radio pulse clusters in the downlink with nine radio pulses each and/or to form radio pulse clusters in the uplink with six radio pulses each.

Preferably, at least nine radio pulse clusters in the downlink and at least twelve radio pulse clusters in the uplink are within coherence time.

Another embodiment of the invention, which is also claimed in parallel, can provide that, in order to reduce the load on the energy buffer or in order to avoid a lower minimum operating voltage,

reducing the length of the radio pulses by increasing the data rate compared to the data rate of 2380371Sym/s, and/or

Preferably, the length of the radio pulse, preferably the length of the extension frame, is limited for the downlink to a value smaller than the maximum possible length of the radio pulse of the radio network, and/or

Limiting the size of the data packet, and/or

Transmitting only radio pulses having a predetermined maximum length and/or allowing for further processing after reception, and/or

Reducing the transmit power to a value less than 10dBm, and/or

Only a subset of the total number of radio pulses of the data packet is transmitted and/or allowed to be used for further processing after reception.

Limiting the length of the respective radio pulse means that only radio pulses corresponding to the predetermined limit are transmitted. In particular, the length of the respective radio pulse is limited in such a way that a maximum transmission time is predefined. Different radio pulse lengths are obtained depending on the payload length. The relationship is not linear but follows a sawtooth function. A larger payload length may also result in a smaller radio pulse length. An additional dummy byte is then added here, for example, in order to obtain a larger payload length, but with a smaller radio pulse length.

Another possible solution to use a small energy buffer consists in limiting the payload, i.e. the transmission of smaller data packets itself. For example, for very small energy buffers, 2 data packets each having 50 bytes may be transmitted, for example, instead of one data packet having 100 bytes. Thus reducing the number of radio pulses per packet. The second data packet is transmitted later, for example after half an hour.

If only radio pulses with a predetermined maximum length are transmitted and/or allowed for further processing after reception, it is ensured that the operating voltage remains permanently above the threshold value. This will either slightly decrease the immunity or there will be some loss of sensitivity.

To relieve the energy buffer, the radio pulses of the core frame may be transmitted at shorter time intervals than the radio pulses of the extension frame.

Furthermore, the number of symbols per radio burst of the core frame in the uplink is preferably limited to a number smaller than the maximum possible number, more precisely preferably to less than 36 symbols per radio burst.

According to the method of the invention, an operating voltage threshold (for example 2.8-3.0V) can be predefined for the energy buffer, which operating voltage threshold is used as a control variable for selecting the method mode according to the invention for reducing the load of the energy buffer. Preferably, the method mode may be selected from a number of multiple possible method modes.

Furthermore, the method pattern may be calculated in advance. A permission determination may then be made at the base station based on the operating voltage threshold in which mode operation should be performed.

According to an exemplary embodiment of the invention, at least two different modes of transmitting and/or receiving radio pulses may be predetermined for selection, said modes having different effects on the discharge of the energy buffer. The preferred node signals which of the at least two modes is suitable or unsuitable based on its energy buffer. A permission determination may then be made, for example, at the base station or in the head end, whether the method mode according to the preceding claim is allowed.

Thus, a plurality of nodes with different energy buffers may be provided in the radio network.

Preferably, an electrolytic capacitor is used as the energy buffer. Such an energy buffer is 5-10 times cheaper than a Hybrid Layer Capacitor (HLC).

The invention also relates to a node according to the preamble of claim 23, characterized in that the microprocessor and/or transceiver of the node operates according to the method of the preceding claims.

Drawings

Examples of advantageous embodiments of the invention will now be described in more detail with reference to the accompanying drawings. The drawings are as follows:

fig. 1 shows a highly simplified schematic diagram of a radio network, preferably an SRD radio network, for applying the method according to the invention;

fig. 2 shows a highly simplified schematic diagram of one example of functional elements comprised by a node of a radio network;

FIG. 3 shows an example of the wiring of an energy buffer of a node according to FIG. 2;

FIG. 4 shows respective exemplary graphs of current consumption and operating voltage curves of an energy buffer of a node over time during transmission of data packets in uplink and downlink;

fig. 5a shows an exemplary illustration of the division of radio pulse blocks into individual clusters in the uplink, with intermittent Δt_add;

FIG. 5b shows an exemplary illustration of forming clusters in the downlink with intermittent DeltaT_add located therebetween;

fig. 6 shows a corresponding exemplary graph of the current consumption and the operating voltage profile of the energy buffer of the node over time during the transmission of data packets in the uplink and downlink in the case of forming individual radio pulse clusters and separating the clusters by intermittent Δt add, respectively;

FIG. 7 shows an enlarged view of a portion of the operating voltage curve of the graph of the uplink in FIG. 6;

FIG. 8 shows a highly simplified schematic of an example of different cluster arrangements according to the invention;

FIG. 9 shows a diagram of increasing data rate as a measure for reducing the load of the energy buffer;

fig. 10 shows a graphical representation of the transmission time of a radio pulse in relation to the payload or the radio pulse length;

fig. 11 shows the division of a radio pulse into two separate radio pulses as a measure for reducing the load of the energy buffer;

fig. 12 shows an example of allowing a radio pulse of a specific length in an extended frame as a measure for reducing the load of the energy buffer; and

fig. 13 shows an example in which radio pulses are omitted as measures for reducing the load of the energy buffer.

Detailed Description

Fig. 1 shows a radio network 100, preferably as defined by type in the ETSI TS103 357 v1.1.1 (2018-06) standard. The radio network comprises a plurality of individual energy-self-sufficient operating nodes 1a-1n and a base station 10 (sometimes also referred to as a data collector). The nodes 1a-1n relate in particular to sensor devices, actuators or combinations thereof for use in so-called IoT. Where data is transmitted from the respective node 1a-1n to the base station 10 by means of radio transmission 9 (uplink) and/or data is transmitted from the base station 10 to the respective node 1a-1n by means of radio transmission 9 (downlink). Each node 1a-1n is located within a transmission effective range or a reception effective range with respect to the corresponding base station 10.

The node 1 may be, for example, a water meter, a gas meter, an electricity meter or an energy meter.

The data of the nodes 1a-1n received by the base station 10 may then be transmitted to the headend 20 or data center by means of a suitable data transmission means 11. The data transmission means 11 may be, for example, a mobile radio connection, an internet connection or a combination thereof. The data transmission takes place by telegram segmentation in a narrow band, preferably in an ultra-narrow band, particularly preferably in the so-called telegram segmentation (TS-UMB family). The uplink generally mainly relates to the transmission of useful data generated in the respective node 1a-1n and/or operational data of the respective node. The data provided by the head-end 20 to the base station 10 via the data transmission means 11 and further transmitted in the downlink by the radio transmission 9 to the nodes 1a-1n are mainly configuration data, data of the operating system for the respective node, software updates, etc.

Fig. 2 shows an exemplary structure of a node 1a for use in the method according to the invention. The node 1a comprises a microprocessor 2, a transceiver 3 and an antenna 4 for sending or receiving radio signals of a radio transmission 9. Furthermore, the node 1a comprises a memory 5, a battery 6 and an energy buffer 7. The battery 6 is preferably a so-called long-life battery, i.e. a non-rechargeable battery, which provides energy to the node 1a throughout its lifetime until the battery has to be replaced. Such a long-life battery has a service life of more than 10 years, assuming that the energy consumption of the node 1a is normal. The supply of energy to the microprocessor 2 or the transceiver 3 or the memory 5 is effected by an energy buffer 7 connected upstream of the battery 6, which is discharged accordingly when an energy demand arises and is subsequently recharged by the battery. The above-described components of the node 1a, such as the microprocessor 2, the transceiver 3, the antenna 4 and/or the memory 5, may also be provided in combination as one component assembly.

Reference numeral 2a denotes quartz, which is provided both as a time measuring device (i.e. a time reference) and is used for generating a carrier signal. The base station is also equipped with quartz (not shown in the figure), which generates a clock for the carrier signal for the carrier frequency of the radio signal emitted by the base station 10 and is responsible for time measurement there. The two quartz differ in terms of their accuracy. The quartz of the base station 10 has an accuracy of about 2ppm, whereas quartz 2a has an accuracy of only about 20 ppm.

As can be seen from fig. 3, the battery 6 has a specific internal resistance 8. The microprocessor 2 and the transceiver 3 constitute a "consumer" of the energy stored in the energy buffer 7. If the energy stored in the energy buffer 7 is consumed by the microprocessor 2 or the transceiver 3, for example because of sending or receiving data packets (telegrams), the energy buffer 7 is discharged for a period of time until it is recharged by the battery 6. Thus, a voltage drop is thereby generated in the energy buffer 7. The voltage drop depends on the energy required by the consumer. The voltage drop and recharging of the energy buffer 7 is shown below by way of an example:

initial voltage U _t1 =3.6v, current pulse t _on The new voltage U is generated by the current i=20ma, the capacitance c=860 μf, and=10 ms _t2 = 3.367V. After the "consumer" has consumed the current, the energy buffer 7 is slowly charged from the battery 6.

Initial voltage U _t1 = 3.367V, recovery interval t _off The battery internal resistance r=1000Ω, and the capacitor c=860 μf generate a new voltage u=150 ms _t3 ＝3.404V。

The electronics of node 1a require a stable voltage of the energy buffer 7 to enable the electronics of the node to function properly. By "stable voltage" is understood a minimum voltage or voltage threshold value, which must not be lowered during operation. For example, the minimum voltage in the conventional node is in the range of 2.7 to 3.0V.

For better understanding, fig. 4 shows, on the left side, the current distribution for transmitting telegrams in the uplink in the conventional telegram segmentation method and on the right side, the current distribution for receiving all subpackets by the nodes in the downlink in the conventional telegram segmentation method as well. The "telegram segmentation method" means information in which one packet is divided into individual sub-packets and these are each transmitted successively as radio pulses, received by the receiver and recombined again into a packet. The time interval t_rb when the transmission of the sub-packets is consecutively performed averages about 150ms in the uplink and about 220ms in the downlink.

According to the invention, the sub-packets may be transmitted over a single frequency channel or alternatively over a plurality of different frequency channels in so-called frequency hopping.

As can be seen from fig. 4, in the conventional method, the energy buffer 7 is strongly discharged by transmitting data packets in the uplink until the energy buffer is charged again above an operating voltage threshold v_min of approximately 2.9V in an intermittent period of 0.37s, based on the charging by the battery 6. When a data packet is received in the downlink by the receiver of the node, the energy buffer is again strongly discharged. Subsequently, it is recharged, which is not shown in the upper illustration of fig. 4. It can be seen that the energy buffer 7 is below the operating voltage threshold v_min line for a considerable period of time in both the uplink and the downlink. So far, so-called Hybrid Layer Capacitors (HLCs) have been commonly used to prevent overdischarge. HLC is expensive.

Fig. 5a and 5b each show a part of a so-called telegram segmentation method, in which a data packet DP is divided, i.e. "segmented" into individual sub-data packets C1 to c1+m, E1 to E1+n, which are provided for transmission in the uplink or reception in the downlink by the respective nodes 1a to 1n, according to ETSI TS103357V1.1.1 (2018-06). For transmitting the data packet DP, the data packet may first be divided into a so-called core frame CF and an extended frame EF, which typically at least substantially comprises useful data and the core frame CF at least substantially comprises control information. For transmission, the data of the extended frame EF are divided into individual sub-packets E1 to E1+ n. Likewise, the data of the core frame CF is also divided into a plurality of sub-packets C1 to c1+m in the uplink, as shown in fig. 5a and 5b, respectively.

In the downlink, as shown in fig. 5B, according to ETSI TS103357v1.1.1 (2018-06), individual sub-packets E1 to e1+n or the radio pulses FB associated therewith are transmitted in a combination of a plurality of blocks B1, B2, …. The adjacent radio pulses generally have a time interval t_rb, as is shown in fig. 5a and 5b, respectively, by way of example for two radio pulses FB of an extension frame. The pause between the core frame and the extension frame is defined as deltat_si in ETSI TS103357v1.1.1 (2018-06). One block B in the downlink comprises for example 18 radio pulses or sub-packets E1-E18 in a conventional radio system. A block interval deltat _ dn is typically provided between the respective blocks, which is allowed in radio standard ETSITS103357V1.1.1 (2018-06) to reach a maximum of 7168 symbols at a symbol rate of reference 2380371 Sym/s. This corresponds to a time value of 3.011 seconds.

One block B in the uplink typically comprises, for example, 24 radio pulses or sub-packets E1-E24.

In order not to fall below the operating voltage threshold v_min of the energy buffer 7, according to one aspect of the invention, it is provided on the one hand that an pause (Δt_add) is provided in the uplink and/or downlink between two adjacent radio pulses (FB) of a frame, which pause is longer than 7168 symbols at a symbol rate of reference 2380371 Sym/s.

Alternatively or additionally, on the other hand, it is provided that the time transmission interval (t_rb (s)) in the uplink and/or downlink is set such that it is greater than 655 symbols at the symbol rate of the reference 2380371 Sym/s.

On the other hand, instead of or in addition to this, it is provided that the radio pulses FB of the core frame CF and of the extension frame EF are divided in the uplink into clusters CL1 and CL2 and that an interval Δt_add is provided between the clusters, which is shown for example in fig. 5 a. Furthermore, according to fig. 5b, corresponding clusters CL each having an intermittent Δt_add can also be formed in the downlink. The blocks B1, B2, … of the extension frame can be divided for this in the downlink and separated from each other by an interval Δt_add, respectively. The clusters CL of different blocks may also here be separated from each other by an interval deltat add. The intermittent ΔT_add is then greater than the block intermittent ΔT_dn. This is shown in fig. 5 b. But alternatively the block pause deltat dn may also be maintained. Preferably, in order to alleviate the load of the energy buffer for generating the number of radio pulses in the corresponding radio pulse cluster, the respective predetermined number of radio pulses per block according to ETSI TS103 357V1.1.1 (2018-06) may be divided by an integer. For example, for the uplink according to fig. 5a, the 24 radio pulses FB of a block B can be divided, for example, into four clusters CL1-CL4, each having six radio pulses and being transmitted offset from one another by means of an additional intermittent Δt_add.

Also in the downlink according to fig. 5b, one block can be divided into two clusters, which each have 9 radio pulses and are received by the node at a distance from each other by means of an additional intermittent Δt_add.

In fig. 5b, the core frame is transmitted without gaps and only the blocks of the extension frame are divided into clusters. Alternatively, however, the core frames may also be divided into clusters by means of additional intermittent Δt_add, that is to say, these clusters are transmitted or received with intermittent Δt_add lying in between, respectively, in order to reduce the energy buffer load.

The length of the intermittent ΔT_add may be constant or different in the uplink and/or downlink. Thus, the length of the pause ΔT_add in the core frame may be shorter than in the extension frame.

Fig. 6 shows, by way of example, in an upper illustration, the currents respectively extracted from the energy buffer 7 in the uplink and in the subsequent downlink. In this illustration, each line corresponds to a cluster CL, which includes a plurality of radio pulses. The time between the two lines corresponds to the corresponding intermittent deltat add. In the example of fig. 6, the intermittent Δt_add is 12s.

The lower diagram in fig. 6 shows the variation of the operating voltage of the energy buffer 7 during the relevant discharge caused by the transmission or reception at the node 1. It can be seen that by forming clusters and corresponding intermittent deltat add, the operating voltage of the energy buffer 7 does not drop below the operating voltage threshold V _ min, both for the uplink and for the downlink, and thus remains at the desired level.

Fig. 7 exemplarily shows an enlarged view of a discharge curve in the downlink in fig. 6, which has six clusters each including nine radio pulses.

In determining the size of the additional intermittent Δt add, i.e. the time interval between the corresponding clusters CL, the so-called coherence time should be taken into account. The coherence time is the time during which the radio pulse FB transmitted can also be used by the receiver without having to readjust the frequency or time. The coherence time is determined in the case of determining the maximum time error in the form of a fraction of the symbol duration (e.g. 0.25). The coherence time depends on the frequency accuracy of the frequency quartz and can be expressed, for example, as follows:

the frequency accuracy of 5ppm corresponds to the carrier frequency of the downlink signal from the base station, since higher quality quartz is generally used there. 20ppm corresponds to the frequency accuracy of the uplink signal transmitted by the node. The value 105.0256 mus is a fraction of 1/4 of the symbol duration. Thus, the offset of the sampling point in the receiver caused by the transmitter and receiver is less than the symbol duration divided by 4. The symbols can be reconstructed well in the receiver. There is no signal-to-noise ratio (SNR) penalty due to offset-based sampling points.

One possibility according to the invention is that the additional pause deltat add is selected according to the upper part of fig. 8 such that the coherence time is maintained. There is then no need to retune the frequency or time in the receiver.

Alternatively, the intermittent ΔT_add may also be selected such that it is outside the coherence time according to the middle part of FIG. 8. The frequency and/or time must then be readjusted.

Alternatively, as shown in the lower part of fig. 8, there are also mixed possibilities. This means that one pause deltat add between two clusters CL is within the coherence time and a second pause between two clusters CL is outside the coherence time. This possibility is particularly interesting for the uplink.

In the uplink, based on the large inaccuracy of the quartz 2a used there, the coherence time is:

after receiving the core frame CF in the uplink, the radio bursts or clusters of radio bursts after the core frame CF may be frequency and/or time readjusted at least once, preferably a plurality of times, in the receiver, i.e. by the base station 10. This gives rise to the advantage that the requirement for time accuracy can be reduced for the following radio pulse FB or radio pulse cluster. Based on this, for the radio pulse FB of the extended frame EF in the uplink, the longer coherence time can thus be estimated as follows:

The coherence time can thus be extended from 5.15s to a maximum of 52.53s. It follows that the radio pulses or clusters of radio pulses CL1, cl+x of the extended frame EF can be separated from each other by using larger pauses (Δt_add2 > Δt_add 1) and do not need to be resynchronized. This is schematically shown in the lower part of fig. 8.

For the downlink, a 2.5-fold improvement (increase in coherence time) can thus be achieved, and for the uplink, even a 10-fold improvement can be achieved, in which the carrier frequency is known after 12 radio pulses are received. Thus, as described above, the accuracy can be reduced to 20ppm. It follows that the number of radio pulses (FB) per radio pulse cluster can be reduced. Thus, for example, only 12 radio pulses are needed in the uplink, and 24 radio pulses are not needed. Preferably, one radio burst cluster (CL 1, cl+x) comprises nine radio bursts in the downlink and twelve radio bursts in the uplink.

Furthermore, after the first frequency and/or time readjustment, the number of symbols per radio pulse (FB) may be reduced to, for example, 24 instead of 36 symbols per pulse.

In the case of a coherence time of 52.53s, in the uplink an intermittent deltat add of e.g. 12s may be set between each, e.g. four clusters CL1-CL4 (each cluster comprising six radio pulses), such that the time is within a coherence time of 52.53s for the total time of the uplink to add up to 36 s.

The length of the time transmission interval (t_rb (s)) may also be extended compared to before based on the first frequency and/or time readjustment.

Thus, by performing at least one frequency and/or time retuning, the average energy consumption per unit time and the average current drawn from the energy buffer for the radio pulses after the frequency and/or time retuning can be reduced and thus the energy buffer is effectively protected.

In order to avoid overdischarging of the energy buffer 7, the data rate can also be increased. The data rate may be increased, for example, compared to the data rate of 2380371 Sym/s. As a result, the data packet or telegram becomes shorter and the energy required from the energy buffer 7 is also reduced. For example, if the data rate is increased by a factor of 2, the radio pulse FB of the data packet is shortened by a factor of 2, whereby a reduction in the load on the energy buffer can already be achieved. Further, increasing the data rate may also be used in combination with setting the intermittent ΔT_add. These two measures can thus be combined with one another advantageously. While increasing the data rate means that the sensitivity is slightly degraded, this still enables the use of cheaper components in the node. The head-end 20 may thus, for example, allocate different data rates for the various nodes. The combination of the increase in data rate with the use of intermittent deltat add is schematically shown in fig. 9.

The radio pulses FB in the downlink have different lengths depending on the payload. Another possibility to relieve the load of the energy buffer 7 consists in allowing radio pulses FB of a certain length so that only radio pulses FB not exceeding this size are transmitted and received by the node.

The graph of fig. 10 shows the relation between the payload, i.e. the length of the radio pulse FB, and the "transmission time" of the radio pulse. As the length of the radio pulse FB increases, its "transmission time" also increases. For a larger payload in a segment, i.e. a radio pulse, more energy is consumed, so that the requirements for the operating voltage of the energy buffer 7 can no longer be met. One measure of the invention is therefore to divide the payload into a plurality of parts and to transmit and/or receive the parts of the payload in sections by means of a plurality of radio pulses in order to meet the voltage requirements. The corresponding partitioning of the payload is schematically shown in fig. 11. Each radio pulse FB1, FB2 contains a portion of the maximum payload PL. This measure can be used alone to reduce the load of the energy buffer 7 or in combination with the above measures (intermittent deltat add and/or increasing the data rate).

Instead of dividing the payload or data packets, those radio pulses exceeding a certain length (l_max) are for example not allowed to be used for reception, i.e. not processed. The relationship between the payload of the saw tooth curve of fig. 10 and the radio pulse length is exemplarily set forth in fig. 12 for a range between 20 and 30 bytes.

Another measure for reducing the load of the energy buffer 7, which can be used alone or in combination with other solutions, consists in omitting the transmission of radio pulses of the data packets and/or the radio pulses of the receive chain. Instead of transmitting or receiving for example nine radio pulses, as can be seen from fig. 13, this may also be only eight radio pulses. The operating voltage of the energy buffer 7 can thus also be kept above the operating voltage minimum v_min. For this purpose only a slightly lower immunity to interference and possibly a little loss of sensitivity has to be accepted. This measure can also be used alone to reduce the load of the energy buffer 7 or in combination with the above measures (intermittent deltat add and/or increasing the data rate and/or dividing the radio pulses).

Another measure for reducing the load of the energy buffer 7 is that the number of symbols per radio burst FB of the core frame CF is preferably limited in the uplink to a number smaller than the maximum possible number. According to ETSI TS103 357 v1.1.1 (2018-06), one radio pulse of the core frame CF in the uplink includes 36 symbols (bits). For example, each radio pulse FB in the core frame CF may transmit only 26 symbols (bits). This reduces the load on the energy buffer 7, as well, in such a way that the discharge of the energy buffer 7 does not drop below the operating voltage threshold v_min. This measure may be used alone or in combination with one or all of the above measures.

As another measure for protecting the energy buffer, the transmit power may be reduced to a value of less than 10 dBm. This measure may also be used alone or in combination with one or all of the above measures.

According to the invention, a specific operating voltage threshold v_min can be predefined for the energy buffer 7, which can be set at the same time as a control variable or as a regulating variable for selecting a method mode, preferably from a plurality of selectable method modes. This method mode may be the above measures: setting an intermittent deltat add, increasing the data rate, allowing a radio pulse of a particular length, omitting a radio pulse, having a smaller number of symbols, or a combination thereof. Since the battery may have different internal resistances and the sensor may have different voltage requirements depending on the product, a predetermined operation mode (which may be selected when needed) may have significant use advantages.

In the same way, according to the invention, the voltage can be monitored as a control variable, and if a specific voltage is present, a specific method mode can be selected in which the energy buffer 7 is protected by the measures.

Another aspect of the invention is to provide at least two different transmission and/or reception modes of the radio pulses or of the radio pulse clusters, which have different effects on the discharge of the energy buffer 7. Where the node 1 can signal to the base station 10 which mode is appropriate based on its energy buffer 7. Communication in the radio network value may then take place with the selection of the appropriate mode. Also, it is possible to calculate in advance which method mode is suitable for which node. Accordingly, only a method mode that reliably excludes the energy buffer 7 from discharging below the voltage threshold v_min may be allowed. This is advantageous when the nodes operate in a radio network (cell) with different energy buffers.

Thus, significant cost savings in node manufacturing of an SRD radio network can be achieved by means of the invention by using a cheaper energy buffer. It should be explicitly noted that sub-combinations of features in the description are regarded as important for the invention even if not explicitly mentioned.

List of reference numerals

1a-1n node

2. Microprocessor

2a Quartz (time)

2b Quartz (Carrier frequency)

3. Transceiver with a plurality of transceivers

4. Antenna

5. Memory device

6. Battery cell

7. Energy buffer

8. Internal resistance of

9. Radio transmission

10. Base station

11. Data transmission means

20. Head end

100. Short-range radio network

FB radio pulse

CF core frame

EX extended frame

C sub data packet

E sub-packet

DP data packet

B block

CL cluster

PL payload

Claims

1. A method for operating a node (1), preferably an end node, in a radio network (100) comprising at least one node (1) and at least one base station (10),

the node (1) comprises a transmitter and/or a receiver for transmitting in uplink and/or receiving in downlink radio messages in the form of Data Packets (DP), preferably a transceiver (5), a battery (6) and an energy buffer (7),

each Data Packet (DP) is divided into a plurality of individual sub-packets in the uplink and/or downlink, preferably sub-packets relating to different frames of the Data Packet (DP), in particular sub-packets (C1 to C1+m or E1 to E1+n) relating to a Core Frame (CF) and/or an Extension Frame (EF) of the Data Packet (DP), and each sub-packet is transmitted and/or received as a radio pulse (FB) in a narrowband or ultra-narrowband, preferably with different frequencies, in time transmission intervals (T_RB (s)), characterized in that,

Provided with at least two, preferably a plurality of pauses (DeltaT_add), the respective pauses (DeltaT_add) being arranged between two adjacent radio pulses (FB) and the symbol rate with reference to 2380371Sym/s being respectively longer than 7168 symbols, and/or

Combining radio pulses (FB) into radio pulse clusters (CL 1, cl+x), the radio pulses (FB) within the radio pulse clusters (CL 1, cl+x) being successively transmitted and/or received with a time transmission interval (t_rb (s)) respectively, and at least one radio pulse cluster (CL 1, cl+x) in the uplink comprising less than 24 radio pulses (FB) and/or at least two radio pulse clusters (CL 1, cl+x) in the downlink comprising less than 18 radio pulses (FB), and/or

The symbol rate of the time transmission interval (t_rb (s)) with reference to 2380371Sym/s is greater than 655 symbols.

2. Method according to claim 1, characterized in that the respective pause (Δt_add) is arranged between two adjacent radio pulses (FB) of a frame, preferably a Core Frame (CF) and/or an Extension Frame (EF).

3. Method according to claim 1 or 2, characterized in that the pause (Δt_add) is arranged between two adjacent radio pulses (FB) of a frame, which respectively belong to different radio pulse clusters (CL 1, cl+x).

4. The method according to the preceding claim, characterized in that the radio pulse clusters (CL 1, cl+x) each comprise the same number of radio pulses (FB).

5. Method according to the preceding claim, characterized in that, in order to generate the number of radio pulses (FB) in the respective radio pulse cluster (CL 1, cl+x), the radio pulses (FB) of each block are divided by a predetermined number according to ETSITS103 357V1.1.1 (2018-06), respectively.

6. Method according to the preceding claim, characterized in that preferably no pause (Δt_add) is provided in the uplink in the first part of the Data Packet (DP) or the first part of the frame of the Data Packet (DP), whereas a pause (Δt_add) is provided in the second part of the Data Packet (DP) or the second part of the frame of the Data Packet (DP), or a pause (Δt_add) of shorter length is provided in the first part of the Data Packet (DP) or the first part of the frame of the Data Packet (DP) than in the second part of the Data Packet (DP) or the second part of the frame of the Data Packet (DP).

7. The method of claim 6, wherein the Core Frame (CF) does not contain a pause (Δt_add) and the Extended Frame (EF) contains a pause (Δt_add), or

The Core Frame (CF) and the Extended Frame (EF) each comprise a pause (Δt_add), wherein the pause (Δt_add) of the core frame is smaller than the pause (Δt_add) of the Extended Frame (EF) respectively.

8. Method according to the preceding claim, characterized in that the position or distribution of the respective pause (Δt_add) within the Data Packet (DP) or frame and/or the length of the respective pause (Δt_add) and/or the number of radio pulses (FB) per radio pulse cluster (CL 1, cl+x) and/or the number of symbols per radio pulse (FB) are determined, respectively, such that the coherence time is maintained.

9. Method according to the preceding claim, characterized in that the radio pulses (FB) of at least one radio pulse cluster (CL 1, cl+x) are within a coherence time, preferably the radio pulses (FB) of at least two radio pulse clusters (CL 1, cl+x) in the uplink are within a coherence time and/or the radio pulse clusters (CL 1, cl+x) in the coherence time are smaller in a first part of the transmission of the Data Packet (DP) than in a second part of the transmission.

10. Method according to the preceding claim, characterized in that the accuracy of the quartz (2 a) of the node (1) and/or the accuracy of the quartz of the base station (10) are taken into account together when determining the length of the pause (Δt_add).

11. Method according to the preceding claim, characterized in that the radio pulses (FB) of at least one radio pulse cluster (CL 1, cl+x) are within a coherence time, preferably the radio pulses (FB) of at least two radio pulse clusters (CL 1, cl+x) in the uplink are within a coherence time, and/or the radio pulse clusters (CL 1, cl+x) within a coherence time in a first part of the transmission of the Data Packet (DP) are smaller than in a second part of the transmission.

12. Method according to the preceding claim, characterized in that a frequency and/or time readjustment, in particular, is performed

The number of symbols per radio pulse (FB) is smaller before the first frequency and/or time readjustment than after the readjustment, and/or

Before the first frequency and/or time readjustment, the corresponding intermittent length (ΔT_add) is short after readjustment, and/or

The number of radio pulses (FB) per radio pulse cluster (CL 1, CL + x) is smaller before the first frequency and/or time retune than after the retune.

13. The method according to the preceding claim, characterized in that the pauses (Δt_add) between the radio pulse clusters (CL 1, cl+x) of the Extension Frame (EF) are larger than the pauses (Δt_add) between the radio pulse clusters (CL 1, cl+x) of the Core Frame (CF).

14. The method according to the preceding claim, characterized in that,

forming radio pulse clusters (CL 1, cl+x) each having nine radio pulses in the downlink, and/or

Radio pulse clusters (CL 1, cl+x) each having six radio pulses are formed in the uplink.

15. The method according to the preceding claim, characterized in that at least nine radio pulse clusters (CL 1, cl+x) in the downlink and at least twelve radio pulse clusters (CL 1, cl+x) in the uplink are within a coherence time.

16. Method for operating a node (1), preferably an end node, in a radio network (100) comprising at least one node (1) and at least one base station (10), in particular according to the preceding claim,

each Data Packet (DP) is divided into a plurality of individual sub-packets in the uplink and/or downlink, preferably sub-packets of different frames relating to the Data Packet (DP), in particular sub-packets (C1 to C1+m or E1 to E1+n) relating to the Core Frame (CF) and/or the Extension Frame (EF) of the Data Packet (DP), and each sub-packet is transmitted and/or received successively as radio pulses (FB), preferably in a narrow band or ultra-narrow band, preferably at different frequencies, at time transmission intervals (T_RB (s)), characterized in that, in order to reduce the load on the energy buffer (8),

Reducing the length of radio pulses (FB) by increasing the data rate compared to the data rate of 2380371Sym/s, and/or

Preferably for the downlink, the length of the radio pulse (FB), preferably the length of the Extension Frame (EF), is limited to a Value (VL) which is smaller than the maximum possible length (ML) of the radio pulse (FB) of the radio network (2), and/or

Limiting the length of the payload to a value less than the maximum possible length of the payload PL, and/or

Reducing the transmit power to a value less than 10dBm, and/or

Transmitting only radio pulses (FB) having a predetermined maximum length and/or allowing for further processing after reception, and/or

Only a subset of the total number of radio pulses (FB) of the Data Packet (DP) is transmitted and/or allowed for further processing after reception.

17. A method according to claim 16, characterized in that the length of the respective radio pulse (FB) is limited such that the maximum transmission time is predetermined by adding an additional dummy byte or the maximum length of the payload PL is limited such that only a part of the Data Packet (DP) is transmitted first.

18. Method according to the preceding claim, characterized in that the radio pulses (FB) of the Core Frame (CF) are transmitted at shorter time intervals than the radio pulses of the Extension Frame (EF).

19. Method according to the preceding claim, characterized in that, preferably in the uplink, the number of symbols per radio pulse (FB) of the Core Frame (CF) is limited to a number smaller than the maximum possible number, preferably to less than 36 symbols/radio pulse.

20. Method according to the preceding claim, characterized by a predetermined operating voltage threshold (v_min) which is used as a control variable, in particular for selecting a method mode according to the preceding claim.

21. Method according to the preceding claim, characterized in that a plurality of nodes (1) with different energy buffers (7) are provided in the radio network (100).

22. Method according to the preceding claim, characterized in that different at least two modes of sending and/or receiving radio pulses are predetermined for selection, said at least two modes having different effects on the discharge of the energy buffer (7), and preferably which of said at least two modes the node (1) signals to fit or not fit on the node based on the energy buffer (7) of the node.

23. Method according to the preceding claim, characterized in that an electrolytic energy buffer or an energy buffer with a maximum capacitance of 25000 μf is used as the energy buffer (8).

24. A node (1), preferably an end node, for a radio network (100), the node being for communication in uplink and/or downlink with a base station (10) of the radio network (100), the node comprising:

-a microprocessor (2),

a transmitter and/or a receiver, preferably a transceiver (5), for transmitting in the uplink and/or receiving in the downlink radio messages in the form of Data Packets (DP),

-a battery (6)

An energy buffer (7), characterized in that,

the microprocessor (2) and/or transmitter and/or receiver, preferably transceiver (5), operates according to the method of the preceding claim.