WO2001097194A1

WO2001097194A1 - Radio link for packet-oriented data transmission

Info

Publication number: WO2001097194A1
Application number: PCT/DE2001/002095
Authority: WO
Inventors: Eduardo De Mier
Original assignee: Iar Systems Ag
Priority date: 2000-06-15
Filing date: 2001-06-07
Publication date: 2001-12-20
Also published as: DE20111114U1; AU2001268945A1; DE10192467D2; DE10028841A1

Abstract

A radio link for packet-oriented data transmission comprises a transmitter (8) and a receiver (9). A sensor (3) generates instantaneous measured quantity values, and an encoding device (5) converts the instantaneous measured quantity values into data packets of a data pack stream, which is transmitted as a radio signal. The transmitter (9) converts the received data packets into measurement information, which is displayed on an output unit (12). The encoding device (5) respectively forms a first instantaneous measured quantity value and a second instantaneous measured quantity value from the measurement signal. The data packet stream comprises both data packets, which contain information regarding the first instantaneous measured quantity value, as well as data packets, which contain information regarding the second instantaneous measured quantity value.

Description

description

Radio link for packet-oriented data transmission

The invention relates to a radio link for packet-oriented data transmission with at least one transmitter and with at least one receiver.

Such radio links are used to transmit data between one or more transmitters and one or more receivers.

A sensor for generating a large number of instantaneous values of a measurement signal is often provided in the area of the transmitter. Such a sensor can be designed as a digital sensor that displays instantaneous values of a measurement signal in a predetermined cycle. It is also possible to provide an analog working sensor, the output signal of which is fed to a digitizing device, which supplies digitized instantaneous values of the measuring signal of the sensor in a predetermined cycle.

In addition, a coding device for converting the instantaneous values into data packets of a data packet stream and a transmitting device for transmitting the data packets as radio signals in the transmitter are provided. If the receiver then has a receiving unit for receiving the data packets in the form of a radio signal and a decoding device for converting the received data packets into measurement information and an output unit for outputting the measurement information thus obtained, then a measurement can also be evaluated in a simple manner over long distances without a cable connection Binding between the sensor and the output unit needs to be provided.

With such radio links, it is often desired to transmit the output signals from several sensors simultaneously. In addition, it is often desired to calculate a number of output variables based on a sensor output signal and to accept these at the output unit of the receiver. The problem that often arises here is that the quantities picked up on the output unit have large errors which are not acceptable in practical operation.

The object of the invention is to provide a radio link in which the measurement information output at the output unit has only a slight error. It is a further object of the invention to provide advantageous uses of such a radio link and a method for operating such a radio link. Finally, a transmitter and a receiver should also be provided for such a radio link.

This object is achieved by the subject matter of the independent claims. Advantageous further developments result from the respective subclaims.

According to the invention, the coding device is designed such that a first instantaneous measured variable value and at least one second instantaneous measured variable value can be obtained from the measurement signal. The second instantaneous measured variable value can be calculated from the first instantaneous measured variable value. It is also conceivable to calculate the second instantaneous measured variable value from several first instantaneous measured variable values, for example from their course. In this way, several instantaneous measurands values formed. In addition, third, fourth, etc. instantaneous measured variable values can also be transmitted. As a result, several measured variables can also be transmitted on a single radio link. The measured variables to be transmitted can also differ in terms of different resolutions, although they result from the same measurement signal.

The data packet stream has both data packets that contain information about the first instantaneous measured variable value and data packets that contain information about the second instantaneous measured variable value.

The invention thus makes it easy to obtain data that result from the sensor signal. In this case, data can be received and transmitted that are supplied directly by the sensor, as well as data that must first be calculated from the sensor signal.

The invention can advantageously be used not only for airborne radio links, but also for

Radio links that are bound to a cable medium. This allows the transmission quality to be further improved. The use of airborne radio links has the particular advantage that the transmitter and receiver are not mechanically connected to one another. This makes it easy to transmit measured values that are taken from rotating shafts, wheels or other moving objects.

In the radio link according to the invention, it is possible to provide both data packets which only contain information about the first instantaneous measured variable value and data packets which only contain information about the second mode mentan measured value included. By transmitting at different times, it is possible to react to different time requirements for the first instantaneous measured variable value or for the second instantaneous measured variable value.

According to the invention, the information about the first instantaneous measured value and / or about the second instantaneous measured value etc. can also be transmitted in each case distributed over a number of data packets. As a result, different resolutions can be generated in the measurement information output by the output unit. Current measured variable values, which must be available with a higher resolution, can advantageously be transmitted in such a way that a large number of data packets are used per transmitted instantaneous measured variable value. In contrast, only one data packet or a few data packets can be used for instantaneous measured value values that are only required with a small resolution. In this way, the maximum bandwidth of the radio link can be adapted particularly simply and advantageously to the time requirements of the instantaneous measured variable values to be transmitted.

According to the invention, data packets can also be transmitted which contain information about a first measured variable value as well as about a second measured variable value etc.

In a further development of the invention, the output unit can estimate and output the course of the measured variables represented by the first instantaneous measured variable values and / or by the second instantaneous measured variable values etc. at times between the receipt or conversion of data packets. This ensures that information on the output from the sensor is constantly on the output unit of the receiver. given measurement signal are present, even if no current instantaneous measured value is being transmitted over the radio link. A model of the system scanned by the sensor is used as the basis for the estimate. In the event that the second instantaneous measured variable values are calculated with the aid of the first instantaneous measured variable values, a particularly precise operation results when the first instantaneous measured variable values are transmitted with a greater frequency than the second instantaneous measured variable values. This is useful, for example, when the resolution of the first instantaneous measured variable values is significantly less than the resolution of the second instantaneous measured variable values. In such a case, information about first instantaneous measured value values arrives at the receiver more often than about second instantaneous measured value values. A reliable estimate of the course of the measured variable, insofar as it is represented by the second instantaneous measured variable values, can then be reliably calculated from the first instantaneous measured variable values.

The radio link according to the invention can be used particularly advantageously for displaying the current driving speed and the distance traveled by a vehicle. The sensor is arranged in the area of a wheel of the vehicle, a sensor being advantageously used which acts as a measurement signal at least every complete revolution of the

Rads gives an impulse. The coding device is then designed such that the instantaneous speed of the vehicle is calculated from the measurement signal using a system time. The instantaneous speed of the vehicle is then transmitted as the first instantaneous measured variable value on the radio link. The number of wheel rotations carried out is the sum of the pulses emitted by the sensor and is calculated and transmitted as the second instantaneous measured variable value. The speed of the vehicle can be calculated from the time interval between two successive pulses at the sensor output. One pulse corresponds to one wheel revolution and thus to a known distance traveled. The second instantaneous measured variable value represents the entire distance traveled up to the time of measurement, which is determined by the sum of all the pulses emitted by the sensor up to that point. Both the first instantaneous measured variable value and the second instantaneous measured variable value are displayed on the output unit of the receiver. The instantaneous speed is transmitted at a rate of, for example, an instantaneous measured value value per second. The total distance determined directly in the transmitter, however, is only transmitted to the receiver at a rate of, for example, 32 seconds per measured variable value.

In the receiver, each new measured value for the speed is multiplied by the time that has elapsed since the last trouble-free transmission of such a measured value. This gives an estimated value for the distance covered in the meantime. This is added to the last total value of the route traveled, which was transmitted without errors, and shown on the display.

If an error has occurred in the transmission of the current measured value values for the speed, an incorrect value will be received and displayed on the receiver side. The error that arises has an effect on the part of the route that is calculated in the receiver. Therefore, an incorrect value is also displayed there. After the next error-free transmission of a second instantaneous measured variable value to the receiver, an error-free value for the total distance traveled is displayed there and for the further calculation of the estimated value used. This results in a reliable and accurate display of the current speed and the total distance traveled, even if the radio link is occasionally subject to interference.

The invention can also be used advantageously for displaying the instantaneous heartbeat rate and the heartbeat variability of a living being. For this purpose, the sensor is designed as a heartbeat sensor, which can be arranged in the area of the nervous system of life. Such a sensor emits at least one pulse as a measurement signal when a heartbeat is sensed. The coding device is designed in such a way that, using a system time, the instantaneous heartbeat rate can be calculated from the measured signal as a first instantaneous measured variable value. Heart rate variability can be derived, for example, from the ratio of the longest distance between two heartbeats to the shortest distance between two heartbeats within a predetermined time period. It can be obtained as a second momentary measured value from the course of the measurement signal.

The radio link according to the invention can also be used particularly advantageously for transmitting the information contained in the electrical pulses generated by a voltage-frequency converter. The coding device is designed such that the instantaneous frequency of the electrical pulses can be obtained and transmitted as a first instantaneous measured variable value. The total number of pulses generated by the sensor can be obtained as the sum of the pulses and transmitted as a second instantaneous measured value. A device in which an analog variable such as a power or a temperature is converted into a continuous pulse sequence with the aid of a voltage-frequency converter can be imagined as a practical application of this embodiment. The frequency of the pulses of this pulse sequence is used as the first instantaneous measured value. The second instantaneous measured variable value results from the integral of the measured variable and represents the work performed in the case of using a power sensor or a transferred amount of heat in the case of using a temperature sensor.

In this embodiment of the invention, the integral of the measurement signal can advantageously be formed by simply counting the pulses of the pulse sequence without long-term errors, for example due to accumulation. This count is transmitted at a low transmission rate over the radio link, while the instantaneous frequency determined in each case is transmitted at a high transmission rate. In the receiver, an accumulation of errors, such as can occur when integrating the first instantaneous measured variable values, is avoided or corrected at regular intervals by a current second instantaneous measured variable value.

The invention also relates to the use of a measuring section according to the invention. A commercial application in connection with a heartbeat sensor is possible, for example, in sports competitions in which athletes' bio data are projected onto a display that is visible to viewers so that they can be seen by the viewers. From such biodata, conclusions can be drawn, for example, about the fitness and enthusiasm of an athlete, which makes sports competitions more attractive for spectators. In animals by Leading people can also avoid undesirable overloads.

Finally, the invention also includes the individual components of such a radio link, such as its transmitter or its receiver.

An idea on which the invention is based is based on the fact that occasional errors can occur on the receiver side when transmitting measured variables over a disturbed radio link. As long as the one submitted on the receiving end. Measured value only serves to be read sporadically by a person, it need not be critical. In the event of an error, a new reading with a certain probability gives a correct value. If the transferred

However, if the measured variable on the receiver side is processed mathematically into a further measured variable, for example by an integration process, errors are summed up, which is disadvantageously noticeable in the long term in the further measured variable calculated in the process. The caused by it

Errors are made up of both transmission errors and rounding errors.

Such errors could be reduced by increasing the bandwidth of the radio link if the frequency of transmission and the resolution of the transmitted measured variable values are increased at the same time. However, this results in increased costs, which is not desirable. The invention takes a different approach. According to the invention, the bandwidth of the radio link is selected so that the transmission of the first measured variable values

Fills most of the available bandwidth. In order to reduce the error in the transmission of the second measured variable values, a correction is applied according to the invention, which in the Comparison to the transmission rate of the first measured variable values need only be made relatively rarely. As a result, a bandwidth is sufficient for the transmission of the second measured variable values, which is less than that for the transmission of the first measured variable values.

The curves of the measured variable represented by the second measured variable values at times between the error-free reception of corresponding data packets are determined by the receiver and, if necessary, are displayed. Whenever a complete and error-free value for the second measured variable value has been received, the estimate formed by the receiver is corrected by the correct value calculated in the transmitter.

The invention also makes use of the following approach. The expected second ^■ Meßgrößenwerte be thus formed not only on the transmitter side, but also on the side of the receiver. The first measured variables formed on the receiver side are regularly compared with the second measured variable values determined on the transmitter side. It is particularly advantageous that no transmission errors are included in the formation of the second measured variable values on the transmitter side. When using voltage-frequency converters, in which the second measured variable values are formed by counting pulses, there are no further errors even apart from the error which is caused by the temporal resolution in connection with the temporal spacing of the pulses.

According to the invention, the resolution of the second measured variable values can be greater than that of the first measured variable values. However, you then need to transfer the second measurement size values more data packets than for transmitting the first measured value value.

When using a voltage-frequency generator, the first measured variable values are determined from the frequency of the pulses generated by the sensor, namely at periodic intervals. Their value corresponds to the inverse of the time interval between two pulses. When calculating the first measured variable values, rounding errors inherently occur, which are to be kept as low as possible in relation to the continuous reading on the receiver side. Minor deviations can, however, be neglected or are accepted by the user. The sum of these errors over a longer period of time cannot be predicted with regard to their size and their sign. As a result, considerable errors could occur in the receiver in a possible sum. Such errors are kept small or avoided entirely by the method according to the invention.

Parallel to the first measured variable value, which is typically transmitted with a width of several bits, the second measured variable values, determined without error, are transmitted with a low bandwidth with only a single bit or with a few bits, which even simplify the data for the user first measured variable value can be appended. The curves of the second measured variable values required for a continuous display on the receiver side are estimated on the receiver side using the curve of the first measured variable values and added to the last completely transmitted second measured variable value. In this way, the course of the second measured variable values can nevertheless be represented at a rate that is higher than the actual transmission rate of the second measured variable values. According to the advantageous embodiment of the invention described above, the complete transmission of a second measured variable value takes a multiple of the time required for the transmission of a first measured variable value. This effect is reinforced, inter alia, by the fact that the second measured value value is often required with a higher resolution than the first measured value value. This is particularly pronounced in the case of the transmission of the current speed and the distance traveled by a vehicle. To display the speed of a vehicle in a predefined speed range between, for example, 0 km / h and 250 km / h, it is often sufficient to display the speed exactly to 1 km / h, which means that a total of 250 resolution steps are required. When the vehicle is driven in a range between 0 km and

On the other hand, 100,000 km with a resolution of "100 m" requires 1,000,000 resolution steps for a complete display, that is 4,000 times more than for a complete display of the speed.

With the invention, in which the second measured variable values are further calculated on the receiver side, the accumulation of an error can still occasionally be observed. However, as long as the transmission duration of the second measured variable values is much shorter than the entire period in which measured variable values are transmitted, it can be assumed that the duration and thus the extent of the error accumulation is limited to a time that the transmission time for the second measured variable values determined by the transmitter does not exceed.

Start of protocol: In a particularly advantageous embodiment of the invention, the transmitter has, in particular, an input unit for inputting or generating a data packet or data record or data, and a transmitter control unit for processing the data packet and for inserting a predetermined test coding resulting from the content of the data packet into the data packet , Furthermore, a transmission unit that can be actuated by the transmitter control unit is provided for transmitting the data packet, the transmitter being designed in such a way that the data packets can be transmitted regularly in succession.

The signals from such a transmitter can be scanned particularly easily by a receiver. In the simplest case, only a single activity of the transmitter needs to be ascertained with only one transmitter in order to predict the further activities of the transmitter. In systems with several transmitters, the transmission times of the transmitters can be predicted just as easily if all the repetition times of the transmitters present in the radio link have been communicated to the receiver beforehand. The receiver then only needs to determine the activities on the radio link and try to receive data packets at the possible subsequent times and at multiples of the repetition times. A transmission method clocked in this way can advantageously be used in those radio links in which it is not particularly important whether each data packet of the data stream is transmitted or not. The invention can thus be used particularly well in radio links for the transmission of measured values in which the transmitted measured value changes only very slowly in comparison with the frequency of transmission of the measured values.

By the provision of a predetermined one which results in particular from the content of the respectively transmitted data packet Check coding in the data packet can be distinguished in a simple manner from properly transmitted data packets from defective data packets, so that only error-free data packets need to be processed further on the part of the receiver.

Corresponding to the transmitter according to the invention, the receiver of the radio link according to the invention has a receiving unit for receiving data packets and a receiver control unit connected to the receiving unit, with which the received data packets can be processed and output. The receiver control unit can each determine a test code of a data packet, it being possible to determine from a comparison of the test code with the content of the data packet whether the data packet has been received correctly or incorrectly. When a faulty data packet is received, the data packet in question is discarded.

The receiver according to the invention is designed in such a way that times for an expected input of one data packet each can be determined. This can be done, for example, by temporarily scanning all activities on the radio link, the receiver being able to be used in a particularly energy-saving manner if it is merely scanned whether there is any activity at all. At predetermined time intervals, attempts are then made to receive data packets from the moment an activity is sensed. Such a simple solution is particularly useful when the time intervals between the data packets sent by the respective transmitters are known to the receiver.

In a development of the invention, the transmitter control unit is designed such that at least one duplicate of the data kets can be created, the data packet and / or the duplicate each having type information. With such type information, the receiver can determine whether the received data packet is a data packet itself or a duplicate of a data packet.

The transmitter is designed in such a way that a data packet and a duplicate can be sent regularly in succession, the time offset between a data packet and its duplicate being variable according to a predetermined transfer rule and transfer information. The relocation information can be provided in a data packet or in a duplicate. By sending one or more duplicates of the transmitted data packet, the recipient can also obtain the data contained in the data packet from the subsequently sent duplicate when receiving a defective data packet. If several duplicates are sent out, the recipient even has several options for reconstructing the defective data in the data packet. The temporal offset between a data packet and its duplicates is known to both the sender and the receiver in accordance with the transfer rule. In a particularly simple embodiment of the invention, the receiver can already predict the expected time of arrival of all subsequent duplicates based on a single relocation information in a single data packet. This results in a particularly secure operation because only little information about the time sequence of sending data packets and duplicates has to be transmitted.

The displacement information can be generated from a predefined counting sequence, in particular using a counter reading with which the transmitters sent by the transmitter Data packets are counted. It is not necessary on the receiver side to actually receive every data packet sent by the sender, because the sender knows the times at which data packets are to be sent. This means that the receiver can also operate the meter without actually having to receive all the data packets sent. Nevertheless, the relative position between duplicates and data packets can still be reconstructed because the meter reading he keeps is always up to date.

By providing type information in the data packet or in the duplicate, the recipient can easily distinguish between data packets and duplicates at any time. This has proven particularly useful when a transmitter and a receiver according to the invention are snapped into place at the start of the operation of the radio link.

Furthermore, each data packet or its duplicate can be provided with identity information associated with the associated transmitter, which can contain information about the type or meaning of the data packets. Thus, a specific sub-ID of the respective transmitter can be assigned to a transmission rate or a transmission grid of the data packets within the radio link. In addition, a meaning of the data transmitted with the data packets can be assigned to a specific sub-ID. For example, transmitted speed data can easily be distinguished from transmitted route data. The identity information can also contain part of unique information about the respective transmitter. This makes it particularly easy to determine within the radio link whether the transmitters switched on in the radio link are really closed belong to the proposed system. In this way, transmitters belonging to another system with a different radio link can be identified in a particularly simple manner, the reception of the undesired data from these systems subsequently being suppressable.

According to the method according to the invention, a search mode and a transmission mode are provided for receiving a data stream having data packets. The following steps are carried out in search mode:

Scanning the data stream for the negotiation of data packets,

Predetermining times for an expected input of a further data packet.

In such a search mode, in the simplest case it is sufficient to scan activities on the radio link caused by data packets. Points in time for the receipt of further data packets after a data packet that was scanned first then result from multiples of a previously known interval time between the respective data packets, which are added at the time the first data packet arrives. In the transmission mode, a data packet is then selectively evaluated, a comparison of the test coding with the content of the data packet being used to determine whether the data packet has been received correctly or incorrectly. In the selective evaluation according to the invention, a receiver which carries out the method according to the invention can be selectively switched on or off.

The method according to the invention can advantageously be improved in that the data stream is scanned for the presence of duplicates belonging to the data packets. If subsequently a transfer rule for a temporal offset between data packets and duplicates is determined from at least one transfer information taken from the data packets and / or their duplicates, there is an increased transmission security. Then, when a defective data packet is received, the transmitted information can still be taken from the duplicate.

In a special embodiment, the receiver is designed in such a way that an identity information assigned to the sender of the data packet or of the duplicate can be decoded from each data packet or from each duplicate. This is used in particular to determine the time interval between two data packets, this being determined by data packets with identical identity information. This enables a particularly fast and precise synchronization of the radio link.

To determine the times for an expected input of a data packet, one can be sent from the receiving unit to the

Receiver control unit delivered signal can also be repeatedly evaluated selectively in a search mode of the receiver. A selective evaluation can consist, for example, in that the signal emitted by the receiving unit is checked for activities at regular intervals. With the receiver according to the invention, times for an expected input of a data packet each are calculated from a starting time when a first data packet is received and from a predetermined interval time, which can be reconstructed in particular from the content or the temporal position of the first data packet. It is also possible to directly reconstruct the interval between two successive data packets from the received data packet, for example wise by evaluating a certain identifier like the sub-ID. This results in a quick and economical calculation of the regular interval between two successive data packets.

In a departure from the above-described method for finding the interval between two successive data packets, times for an expected input of one data packet can also be calculated from a interval between two data packets, which is based on a start time on receipt of a first data packet and a repetition time on receipt of one further data packet is determined.

The invention is also in a combined transmission

/ Realized reception module for a radio link, which has a transmitter and / or a receiver according to the invention. The receiver and the transmitter can also be operably connected to one another to avoid collisions of data packets or their duplicates. When scanning a data packet sent by a further transmitter, the receiver can temporarily suppress the transmitter connected to it or have data packets sent with a changed time interval.

With the radio link according to the invention, long-term operation of the transmitter and receiver is possible if these are powered by batteries. This results in possible uses, particularly in connection with sports watches, which evaluate speed and heartbeat sensors. The system according to the invention can advantageously be used in both unidirectional and bidirectional systems, each consisting of a receiver and a plurality of transmitters. The invention System has a high immunity against transmitters of similar neighboring systems and against collisions of the transmitters of a system with one another. There is also a high immunity to external radiation. Finally, from the perspective of an end user, simple commissioning or uncomplicated operation is guaranteed.

In the protocol according to the invention, the information is transmitted in the form of recurring transmission packets with typically 8 to 16 data bits and various control and test bits. In addition, a number sequence generator can be used to provide transmission packets scattered over the time range redundantly to the regular transmission packets which follow one another at fixed intervals. After a synchronization phase, the location of all incoming packets can be calculated for the recipient. By switching the receiver and the transmitter on and off, low power consumption is achieved.

The invention can be used particularly advantageously in applications which require unidirectional transmission of data at a low data rate. There are advantages in long-term operation, such as the monitoring of measurement data, which change at a rate in the range of a few Hertz. This can advantageously be used for the regular transmission of speed information. After a short preceding synchronization time, ¹ transmission of data is possible in the invention. Short-term operation such as remote control of devices can be achieved with additional procedural effort. Moreover, it is possible to decompose in the transmitter aufakkumulierte route information in the data areas and the data areas separately - each provided with at least one redundant packet - to send to the receiver, wherein ^■ they are assembled there back to the original route information.

Systems with several transmitters which, despite the occurrence of collisions between data packets and other disturbances, are to be received by a receiver at as uniform a rate as possible, can be achieved by the redundancy functions according to the invention with an extremely economical long-term battery operation at the same time. These include, for example, sports computers, medical devices for patient monitoring, ■ alarm systems, monitoring systems in the industrial and home user sector as well as measurement data transmission.

With the invention, especially in the case of sports computers such as those for bicycles, there is an improved transmission protocol with which a single receiver can be used for all transmitters in a system. All transmitters then transmit on a common frequency, whereby a maximum number of 4 or 6 or 8 transmitters has proven successful. With the invention, a high transmission rate can be achieved in a given time frame, collisions between the various transmitters or sensors of a system being avoided. The radio link according to the invention has a high immunity to atmospheric interference and transmitters from other systems. The invention also results in a very low average activity of the receiver and transmitter modules, so that a low power consumption of the radio link can be achieved. Accordingly, the invention also includes the use of a protocol for data transmission, in which data words are converted into one or more data packets before being sent. Each transmitter on the radio link has a different sub-ID, which indicates the respective sensor type within a system. In this way, sensors for a heartbeat, for a wheel revolution or for a pedal frequency can be distinguished using the sub-ID. In addition, each transmitter module has a unique ID or serial number, regardless of the sub-ID. This is written, for example, during a production test in a non-volatile memory area of the transmitter, or determined randomly when a new battery is inserted. A specific, fixed packet repetition time or packet frequency is assigned to each sub-ID. The packet frequency is independent of the frequency with which the measured values arrive or change. In parallel to the term packet frequency, a term "time slot" can also be used. It is a grid of time intervals that correspond to the packet length. The distance between two packets from a sender is always an integer number of timeslots. The packet spacing of the individual sub-IDs always differs by an even number.

In order to avoid collisions within a system of a radio link, the aim is to ensure that for each transmitter the collision of its packets with packets from another transmitter of the same system is no longer interrupted than one packet in succession. Depending on the sub-ID, the transmitters according to the invention have a different fixed packet frequency, which they receive by coding within the system. This

Coding varies in steps, so that the period length of the packet frequency increases from transmitter to transmitter by twice the packet length. It is easy to realize that then with two transmitters that have two different packet frequencies, two packets in a row cannot actually collide.

Basically, however, it applies that with a number of N transmitters, in the worst case, N-1 packets of one of the transmitters can be disturbed in succession. However, this case is unlikely and is of lesser importance in reality. In order not to exceed a prescribed maximum transmission time, one could now multiply the frequency of the packets sent by N. In this case, four transmitters would have to transmit four times more packets per second than with a "normal" data transmission. However, this requires increased power consumption by the sender and receiver. According to the invention, a similar effect is achieved with less effort.

The throughput of the entire time slice with transmission packets is calculated from the sum of all packet frequencies and the respective packet duration. This parameter, which can also be called "occupancy", gives a measure of the strength of the system against non-system disturbances. The more packets are on the radio link and the longer they are, the higher the likelihood that a short interference pulse will collide with one of these packets.

In order to avoid collisions between two transmitters of neighboring, each radiating radio links, in addition to the fixed packets, which are transmitted and received at a constant frequency, a packet with a variable position or a redundancy packet can be sent out between two fixed packets. The time slot in which the redundancy package is placed is defined by a number sequence rator determines, the sequence of which may depend on the ID of the respective transmitter. The algorithm for the number sequence is known to both the sender and the receiver. After a synchronization time, the respective IDs of the individual transmitters are also stored in the receiver, so that they can also be used as parameters in the number sequence. The sender can thus calculate in advance in which time slot the next redundancy packet is to be expected and accordingly switch on the receiving device at exactly the right time. Starting information for the number sequence generator transmitted in each case in a data packet identifies a zero crossing of the number sequence, so that the transmitter and receiver can be synchronized on the basis of this data packet.

The sender's ID is transmitted periodically within the data packets, piece by piece. In total, only as many components of the serial number need to be transmitted as are used to individualize the number sequence passing through the number sequence generator. This speeds up the transfer of the transmitter's ID or serial number. Likewise, multi-digit, accumulated route information can be reliably transmitted in a simple manner.

Before a receiver of a radio link knows which transmitters of the radio link are to be counted towards his radio link based on their ID, he must correctly receive the IDs of the respective transmitters at least once and store them permanently. To do this, a corresponding mode is selected in the receiver and at the same time it is ensured that all transmitters in your own system are active. In addition, it must be ensured that no transmitters of a second, similar system cross-talk. In such a state, the IDs can be taught in reliably. In normal operation, the receiver according to the invention switches on at the respective time of receipt of the fixed packets and does not take the redundancy packets into account. If a fixed packet cannot or cannot be received due to external interference or collisions in the radio link, the receiver tries to replace the missing fixed packet with the next redundancy packet or further redundancy packets. This is achieved with the aid of the number sequence known on both sides for the calculation of the temporal position of the redundancy packets. When the interference on the radio link ceases, the receiver limits itself to receiving fixed packets. This keeps electricity consumption low.

When it snaps between the transmitter of a radio link and the receiver or when it wakes up from a mode with reduced energy consumption, the receiver can also react to the transmitter of a neighboring system. Using the IDs of the system's transmitters, which are taught in in a special mode, it can, however, be determined • whether the transmitters found when they are snapped in belong to your own system or not.

The transmitters can be designed as microcontrollers with an internal EEPROM for the ID number. The respective sub-ID and the packet frequency of the system can be permanently set using external pins or can be configured using entries in the EEPROM. The ID is read from the EEPROM after a reset or generated at random. For test purposes, the entire ID is sent out once after the reset. When using microprocessors with an integrated EEPROM, the ID can also be serially written into the block during the test and checked for correct writing by resetting again. Finally, it is also conceivable to provide the radio link according to the invention in a fitness computer, in which a transmitter can be connected to a sensor for measuring the heartbeat of a user or for measuring his step frequency. Such a fitness computer can have a receiver with a display for displaying the value transmitted by the sensor.

The invention is illustrated in the drawing using an exemplary embodiment.

FIG. 1 shows a schematic illustration of a motor vehicle equipped with the radio link according to the invention;

FIG. 2 shows a voltage-time diagram of an electrical signal which is emitted by the sensor of the radio link from FIG. 1, FIG. 3 shows the format of a data packet which is transmitted in the radio link from FIG. 1,

FIG. 4 illustrates the chronological sequence of data packets of the radio link from FIG. 1 and FIG. 5 illustrates the contents of the data packets according to FIG. 4. FIG. 6 shows a schematic illustration of a radio link according to the invention which has three transmitters and one receiver, FIG. 7 illustrates those from the transmitters signals given from FIG. 1 with regard to their chronological sequence, FIG. 8 illustrates the structure of a data packet emitted by a transmitter from FIG. 6 or its duplicate,

FIG. 1 shows a radio link according to the invention, which is used to measure the distance covered and the current speed of a motor vehicle. From this motor vehicle, only one impeller 1 can be seen, which has several spokes, a permanent magnet 2 being attached to a spoke. In the area of the impeller 1 there is also an inductive sensor 3, which is connected to a coding device 5 via a sensor line 4. The coding device 5 is in turn connected to a transmission device 6 which can transmit radio signals via a transmission antenna 7.

The inductive sensor 3, the coding device 5 and the transmitting device 6 form a transmitter 8 which, together with the receiver 9 shown in FIG. 1, provides a radio link.

The receiver 9 is divided into a decoding device 10, which is connected to a receiving antenna 11 and to an output unit 12. The output unit 12 in turn is connected to a two-part display unit 13. The display unit 13 is designed such that a speed "10 km / h" of the vehicle is displayed in a first display area I, while in a second display area II a distance traveled "130 km" of the vehicle is displayed.

FIG. 2 illustrates the chronological sequence of the signals emitted by the inductive sensor 3 via the sensor line 4 when the impeller 1 is rotated about its axis. In the present case, the impeller 1 makes six revolutions, braking from a high number of revolutions to a low number of revolutions. As can be seen particularly well in FIG. 2, a total of three are in the range from 0 to approx. 1 sec

Generated pulses Ul, U2 and U3. The pulse U4 is generated at the time t = 2 sec, the pulse U5 is generated at the time t = 3 sec and the pulse U6 is generated at the time t = 4 sec.

The pulses U1 to U6 form the measurement signal emitted by the inductive sensor 3, which is passed on to the coding device 5. In the coding device 5, instantaneous speed values are calculated from this measurement signal by dividing the circumference of the impeller 1 by the time interval between two successive pulses which are emitted by the inductive sensor 3. This speed information is packed into data packets and transmitted by the transmitting device 6 via the transmitting antenna 7. In addition, the pulses emitted by the inductive sensor 3 are counted by the coding device 5 and multiplied by the circumference of the impeller 1 to cover a distance traveled. At the same time intervals, the coding device 5 converts the current value of the route covered into a total of four data packets which are transmitted via the transmitting device 6 and the transmitting antenna 7. In an embodiment not shown here, this multiplication can also take place in the receiver 9. The format of the data packets generated by the coding device 5 is illustrated in FIG. 3. A data packet 20 is shown there, which can be transmitted by the transmission device 6. The data packet 20 represents a so-called "raw" data packet which can also be provided with synchronization information and with validation information for transmission from the transmission device 6. FIG. 3 thus shows only those subareas of the data packet 20 which are relevant for the acquisition of measurement information.

The data packet 20 has an identification bit 21, the content of which provides information as to whether speed information or route information is being transmitted. In addition, two rank bits 22 are provided, which provide information about the rank of a data packet within a series of several data packets with which related components of a single piece of information are transmitted. Two test bits 23 and a total of eight data bits 24 serve to record the data that are generated by the decoding device 10.

In the present case, the eight data bits 24 of the data packet 20 can assume a total of 2 ⁸ (= 256) different values. With a resolution of 1 km / h, this results in a speed range from 0 km / h to 255 km / h, which can be covered by the coding device 5. A binary content of the data bits 24 of "0000 0000" corresponds to the speed 0 km / h and a value "1111 1111" corresponds to a value of 255 km / h.

In the event that 20 route information is to be transmitted with the data packet, the present embodiment proceed as follows. The route information is transmitted as an eight-digit decimal number. With a resolution of "10 m", total distances of a total of 999,999.99 km can be transmitted. This information can be encoded with a total of four data packets 20 if two decimal places of the eight data bits of a data packet 20 are reproduced. For this, two binary-coded decimal numbers are transmitted. In this coding, the decimal numbers between 0 and 9 can be represented with four bits each. A total distance of 1,242.42 km, i.e. 1 242 420 m, is represented by the following binary-coded decimal number:

0000 0000 0001 0010 0100 0010 0100 0010 0 0 1 2 4 2 4 2 - IIχ II ₂ H ₃ H

In the coding reproduced above, the designations II _I , II ₂ , II ₃ and II _{4 represent} the respective numbering of the four data packets which are used to transmit such route information.

FIG. 4 illustrates the temporal sequence of the transmission of data packets by the transmission device 6 via the transmission antenna 7. As can be seen particularly well in FIG. 4, one data packet is transmitted at a time interval of 0.1 sec. Data packets I, which have speed information, alternate with data packets Ili, which have route information. The route information Ili is coded as explained above with reference to FIG. 3. As can be seen particularly well in FIG. 4, a total of three speed information items I are transmitted for each complete transfer of route information IIχ to II ₄ .

FIG. 5 illustrates the content of the individual data packets from FIG. 4.

It is in the first column under the designation "serial no." the time at which the data packet sent out in the relevant line is shown in FIG. 4.

As can be seen particularly well in FIG. 5, the data packets I sent out at odd times "1, 3, 5, ..., 21" each have a value "0" in identification bit 21. This indicates that the value transported in these data packets each represents a speed value. In contrast to this, the data packets transmitted at even times "2, 4, 6, ..., 20" each have a value "1" in identification bit 21, which indicates that a route value is transmitted in each of these data packets. In the case of route values, the contents of the rank bits 22 provide further information about which digits of the decimal route information are currently being transmitted. A total of four data packets are provided for the transmission of a route value, so that depending on the rank of a data packet within the

Route specification, the check bits 23 have one of the binary values "00", "01", "10" or "11".

The data packets thus transmitted by the transmitter 8 are received by the decoding device 10 via the receiving antenna 11 and broken down into their individual components. In the event that the presence of a data packet is identified, the value "0" of the identification bit 21 indicates that it is speed information, this speed information is first checked to see whether it is error-free. For this purpose, the content of the check bits 23 is compared with the other contents of the data packet 20. In the event that this comparison reveals that there is an error-free transmission of this data packet, the corresponding content of the data bits 24 is decoded and forwarded to the output unit 12. In the present case, the output unit 12 displays the value corresponding to the speed information of the data packet in the first display area I of the display unit 13. Each time a further data packet I arrives, which contains speed information, the procedure described above is followed, so that the first display area I of the display unit 13 always shows a current speed value of the vehicle, provided that an error-free data transmission has taken place.

When a data packet Ili is received, which is indicated by the content "1" in the identification bit 21, the decoding device 10 first checks on the basis of the content of the check bits 23 and the other contents of the relevant data packet whether there is a data packet transmitted without errors. If this is the case, the decoding device 10 uses the rank bits 22 to check the rank of the current data packet. Thereupon, a comparison is made as to whether a data packet with such a rank is currently required in order to possibly complete previously received data packets with route information. In this way, the process continues until complete current route information is available in the decoding device 10. If there is a complete stretch keninformation this is forwarded to the output unit 12, which displays the route information in the second display area II of the display unit 13.

In the manner described above, speed information and route information are continuously transmitted from the transmitter 8 to the receiver 9.

In the event of malfunctions in the transmission between transmitter 8 and receiver 9, it can happen that individual data packets arrive garbled at the receiver 9, so that they cannot be evaluated there. In the case of a defective data packet that contains speed information, this can still be accepted by a user. In the worst case, speed information that does not apply over several transmission periods is displayed.

In the event of a faulty transmission of a data packet which contains route information, the decoding device 10 discards the corresponding data packet. In this case in particular, an estimated change in the route information displayed in the second display area II is calculated in the decoding device 10. For this purpose, the speed information decoded in the meantime is converted, together with the time elapsed since the last complete route information was received, to an estimated route change, which are added to the route information displayed in the second display area II of the display unit 13. In this way, new current total route information is calculated and displayed until an error-free group of data packets has been received in the receiver 9 which contain a current total route. The same procedure is followed at times when the current route information is currently being transmitted. Each time an error-free speed information arrives, an estimated change in the route information is calculated from the past time and added to the route information last transmitted.

The case of a faulty transmission of a data packet is illustrated below with reference to FIG. 5. In normal, undisturbed operation of the transmitter 8 and the receiver 9, data packets are transmitted, as is illustrated by the data packets with the serial numbers 1 to 9. After the data packets 2, 4, 6, 8 have been transmitted, the receiver 9 has all the information II _{1 #} II ₂ , II ₃ , II ₄ which are required for calculating a total distance transmitted by the transmitter 8. On the basis of this total route, the receiver 9 calculates estimated route changes in each case using the speed information transmitted in the data packets 9, 11, 13 and 15, by multiplying the respective speed information by the transmission time between two speed data packets. The corresponding value is added to the last total distance transmitted and displayed. In the present case, in which the data packet 14 is disturbed with route information II ₃ , no new overall route can be extracted from the data packets 10, 12, 14 and 16. In this case, the data packets 10, 12, 14 and 16 are discarded and no longer used. Rather, the receiver 9 further calculates the total route information based on the value transmitted with the data packets 2, 4, 6, 8, in that new route changes are also estimated with the speed data packets 17, 19, 21 and so on and the last one transmitted Value of the total distance can be added. This continues until complete route information is again error-free from the transmitter 8 is transmitted to the receiver 9. In this case, the total route information updated with estimated values is replaced by current total route information transmitted without errors.

When the transmitter 8 and the receiver 9 are operating, the case may occur that the total distance counter in the transmitter 8 has a lower value than the total distance counter in the receiver 9. This indicates that a so-called "overflow" of the total distance counter in the transmitter 8 has taken place. This is taken into account by the receiver 9 so that it is assumed that exactly one overflow has occurred. This overflow is then taken into account accordingly in the new display of the total route information in the receiver 9.

In this case, the "true" distance covered by the impeller 1 is only recorded by the receiver 9. In this case, the transmitter 8 can only store values which are limited by the size of the total distance counter in the transmitter 8. According to the invention, this can be used particularly advantageously to keep the size of the total distance counter in the transmitter 8 comparatively small compared to the size of the total distance counter in the transmitter 9. This reduces the data to be transmitted on the radio link, so that the transmission rate can be increased with regard to the speed information. In a special embodiment of the invention, not shown here, exactly one route information data packet is sent for every 10 speed data packets.

In another embodiment, not shown here, both speed information and route information are transmitted in a single data packet, with both for example, of a total of 9 data bits of a data packet, 8 data bits are used for the transmission of speed information, while exactly one data bit is used for the transmission of part of the route information. In this way, exactly one route information item can be reconstructed from 8 successive data packets, while a total of 8 speed information items have been transmitted.

FIG. 6 shows a schematic illustration of a radio link 101 according to the invention, which comprises a first transmitter 102, a second transmitter 103, a third transmitter 104 and a receiver 105. The first transmitter 102 has a first antenna 6 for transmitting radio signals. The first antenna 106 is connected to a transmission unit, not shown in this view, which generates the radio signals to be transmitted by the first antenna 106. Furthermore, the first transmitter 102 comprises a transmitter control unit (not shown in this view) for controlling the transmitter unit. Via a first input line 107, the transmitter control unit receives signals from a first sensor 8, which is designed as a revolution counter of an impeller (not shown in this view). The first sensor 108 thus supplies position information about the impeller to the transmitter control unit via the first input line 107. The transmitter control unit converts this position information into digital data and causes the transmitter unit to transmit this digital data via the first antenna 6. Both the instantaneous speed and the total distance traveled by the wheel are transmitted, as has been explained above with reference to FIGS. 1 to 5. The second transmitter 103 has a second antenna 109 and a second input line 110 and essentially corresponds to the first transmitter 102 with regard to its remaining structure. Via the second input line 110, the second transmitter 103 receives signals from a second sensor 111, which evaluates position information about a pedal crank (not shown here) of a bicycle. The second transmitter 103 converts this position information into digital signals which are emitted as radio signals via the second antenna 109. Both the current position information and its integral are transmitted over time, as was explained above with reference to FIGS. 1 to 5.

The third transmitter 104 comprises a third antenna 12 and a third input line 113, via which data are recorded by a third sensor 114. With regard to its remaining construction, the third transmitter 104 essentially corresponds to the first transmitter 102. The third sensor 114 determines the current heartbeat frequency and its integral over time, which allows a conclusion to be drawn about the energy consumption of a person who is not shown in this view and who is traveling on a bicycle. These data are converted into digital data by the third transmitter 4 and emitted as a radio signal via the third antenna 12. Both the current heartbeat frequency and its integral are transmitted over time, as was explained above with reference to FIGS. 1 to 5.

The receiver 105 has a receiver antenna 115 for receiving the radio signals emitted by the first transmitter 102, the second transmitter 103 and the third transmitter 104. The radio signals received by the receiver antenna 115 are forwarded to a receiving unit, not shown in this view, which is operably connected to a receiver control unit, also not shown in this view. The receiver unit can be switched on and off by the receiver control unit. The receiver control unit can also put itself in a switched-off state. The receiver control unit converts the data received by the receiver unit and shows it on a display 116. The display 116 can show the transmitter from which the data shown in the display 116 was sent. The content of the respective data can also be displayed. Furthermore, the receiver 105 has an operator key 117 with which the receiver control unit can be operated by a user.

During operation of the radio link 101, the first transmitter 102, the second transmitter 103 and the third transmitter 104 continuously transmit data which is received by the receiver 105, evaluated and shown on the display 116.

FIG. 7 illustrates the radio signals emitted by the first transmitter 102, the second transmitter 103 and the third transmitter 104 with regard to the chronological sequence of the data transmitted by them. Information is only shown for part of the data that is emitted by the first transmitter 102, the second transmitter 103 and the third transmitter 104. In the example shown, only the transmission of those data which are labeled with "I" in FIG. 4, that is to say the regularly transmitted speed data, is illustrated. It goes without saying that the route information correspondingly labeled "II" in FIG. 4 can also be transmitted with a fixed packet and with a redundancy packet. FIG. 7a shows a first timeline 120 which contains a first ^' fixed packet F1 and a first redundancy packet R1. The first fixed packet F1 and the first redundancy packet R1 are each formed by a data signal that is modulated onto a carrier signal with a carrier signal frequency. In principle, any modulation method can be used for this.

As can be seen particularly well in FIG. 7a, the transmission of the first fixed packet F1 begins at time ti. The transmission of the first redundancy packet R1 begins at a time t ₂ . The length of the first fixed packet F1 and the length of the first redundancy packet R1 are essentially the same.

FIG. 7b illustrates the radio signal emitted by the second transmitter 103 on the basis of a second time line 121. It comprises a second fixed packet F2 and a second redundancy packet R2, which are modulated as data signals onto a carrier frequency that corresponds identically to the carrier frequency of the first transmitter 102. The second fixed packet F2 is sent out at a time t _x and the second redundancy packet R2 is sent out at a time t ₃ , the difference t ₃ -t ₂ in the second transmitter 103 being smaller than the difference t ₂ -t in the first transmitter 102 In this way, a temporal collision of first fixed packet F1, second fixed packet F2, first redundant packet R1 and second redundant packet R2 is avoided in such a way that at least one of the data packets per transmitter does not coincide with all data packets of the other transmitter.

FIG. 7c illustrates a third timeline 122 on which a third fixed pair transmitted by the third transmitter 104 ket F3 and a third redundancy package R3 are shown.

The third transmitter 104 transmits on the same carrier frequency as the first transmitter 102 and the second transmitter 103, the third fixed packet F3 and the third redundancy packet R3 being modulated onto a corresponding carrier signal. As can be seen particularly well in FIG. 7c, the transmission of the fixed packet F3 begins at time t _lr while the transmission of the third redundancy packet begins at time t ₄ . The time difference t ₄ -tχ of the third transmitter 104 differs from the corresponding time differences t ₃ -t! of the second transmitter 103 and t ₂ -tι of the first transmitter 102.

FIG. 7d uses the first time beam 120 to illustrate the time interval t ₀ between two fixed packets Fl of the first transmitter 102. The distance t ₀ is essentially identical between two successive fixed packets F1. As a result, the fixed packets F1 are sent out at regular time intervals.

FIG. 7e uses the second timeline 121 to illustrate the time interval t ₀ 'between two second fixed packets F2 of the second transmitter 103. The second fixed packets F2 are transmitted by the second transmitter 103 at regular time intervals.

FIG. 7f uses the third timeline 122 to illustrate the third fixed packets F3 delivered by the third transmitter 104. The third fixed packets F3 are each sent out regularly in succession at a time interval t ₀ ″. The respective time intervals t ₀ , t ₀ 'and to' ¹ differ from one another, so that in most cases the fixed packets transmitted by the first transmitter 102, the second transmitter 103 or the third transmitter 104 do not overlap. This enables the operation of several transmitters together with a single receiver.

In the present case, there is also the fact that each transmitter does not regularly send out just one type of fixed packet - namely, for example, the speed information. Rather, two types of fixed packages - namely e.g. still the integrated route information - sent out.

FIG. 8 illustrates the structure of a data packet 125, the structure of which is essentially the same as that of the first fixed packet F1, the second. Fix package F2, the third fix package F3 or with the first redundancy package R1, with the second redundancy package R2 or with the third redundancy package R3. The data packet 125 is divided into a first identification area 126, a type area 127, a relocation information area 128, a second identification area 129, a user data area 130 and a check code area 131.

The first identification area 126 is used to hold information that specifies the so-called sub-ID of the respective transmitter. The sub-ID of the respective transmitter can contain information about the time offset between a fixed packet sent by the transmitter and the corresponding redundancy packet. Similar to the allocation of channels for radio links that use predetermined bandwidths of radio signals, time slice areas can be used when using a single predetermined transmission frequency become. The time slice areas defined in this way are advantageously clearly identified and - each assigned to a transmitter - are reproduced in the first identification area of a fixed packet or redundancy packet transmitted by the relevant transmitter.

The type area 127 receives information about whether the respective data packet is a fixed packet or a redundancy packet.

The offset information area 128 remains unused in a simple operation of the radio link 101 according to the invention without redundancy packets. In an advantageous development, the information contained in the displacement information area 128 together with the information in the first identification area 126 provide information about the time interval between which the redundancy packet following a fixed packet appears. For this purpose, a calculation rule or a counting sequence can be provided in the corresponding transmitter of the data packet 125, according to which the time interval between the fixed packet and the redundancy packet subsequently sent is determined. If such a sequence is controlled by a counter, then the respective counter reading can be recorded and transmitted in the offset information area 128.

The second identification area 129 can be used to receive a serial number which is only assigned once and which enables a transmitter of the radio link 101 to be distinguished from a transmitter of another radio link.

The useful data area 130 receives the data to be transmitted by the radio link 101. The check code 131 is used at a reception of the Datenpa- ¹ kets 125 to determine whether the transmitted data have experienced in the meantime unwanted changes. For example, a parity method or a checksum method can be used to generate the content of the check code area 131.

Furthermore, the data packet 125 still has scan, synchronization and start data, not yet shown in this view, which are conditioned and designed in particular by the mechanical processing of the data packet 125.

In the normal case, in which the presence of the first transmitter 102, the second transmitter 103 and the third transmitter 104 is scanned, the receiver 105 switches to an active mode. In the active mode, which represents the normal operation of the radio link, the receiving unit is kept essentially off. The receiving unit is switched on only at times when the receiver control unit expects the expected receipt of a fixed package from one of the transmitters. In the active mode, the exact location of the fixed packages received is constantly checked and, if necessary, minor errors in the location calculation are corrected by the receiver control unit. In the active mode, the data is also transmitted within the radio link 101, evaluated by the receiver control unit and forwarded to the display 116.

Starting from the active mode, the receiver 105 enters a redundancy mode 146 if the information contained in the check code area 131 of a received fixed packet indicates when evaluating the data packet that the data packet ket has been falsified or incompletely transferred. In the redundancy mode, the receiver unit is switched on by the receiver control unit when a redundancy packet is to be evaluated for a specific ID of the transmitter for the incorrect or not received fixed packet. The exact position in time of receipt of the redundancy packet for the relevant fixed packet results from the sequence of numbers which is followed up in the receiver control unit.

After receiving the corresponding redundancy packet, the receiver 105 returns to the active mode in which it evaluates successive fixed packets.

A special situation for the receiver 105 is an teach mode in which the radio link 101 is operated shielded from other radio links and interference. In the teach-in mode, it is scanned which transmitters are in the vicinity of the receiver 105. Their IDs are then received and permanently stored in the receiver 105. It must of course be ensured that all transmitters of the radio link 101 are active and that no transmitters on a second radio link interfere with the transmission.

Claims

claims

1. Radio link for packet-oriented data transmission with. at least one transmitter (8) and with at least one receiver (9), the transmitter (8) each having at least one sensor (3) for generating a large number of instantaneous measured variable values of a measurement signal, a coding device connected to the sensor (3) (5) for converting the instantaneous measured variable values into data packets of a data packet stream and a transmitting device (6) for transmitting the data packets as a radio signal, and wherein the receiver (9) has a receiving unit for receiving the data packets as a radio signal, a decoding device (10) to convert the received

Data packets in measurement information and an output unit (12) for outputting the measurement information, the coding device (5) being further designed so that a first instantaneous measured value and at least one second instantaneous value can be obtained from the measurement signal, the data packet stream including both data packets which contains information about the first instantaneous measured variable value, and also has data packets which contain information about the second instantaneous measured variable value or about the second instantaneous measured variable values.

2. Radio link according to claim 1, characterized in that the information about the first instantaneous measured variable value and / or about the second instantaneous measured variable value can each be distributed over a plurality of data packets.

3. Radio link according to claim 1 or claim 2, characterized in that

Data packets are provided, which only contain information about the first instantaneous Meßgrößenwert, and in that data packets are provided, which only contain information about the second instantaneous Meßgrößenwert ^•.

4. Radio link according to one of the preceding claims, • characterized in that ^; the output unit is designed such that the course of the measured variable represented by the first instantaneous measured variable values and / or by the second instantaneous measured variable values can be estimated and output at times between the reception and / or the conversion of data packets.

5. spark gap according to one of claims 1 to 4 for displaying the current driving speed and the distance traveled by a vehicle, the sensor (3) being arranged in the region of a wheel (1) of the vehicle and as a measurement signal at least every complete revolution of the wheel ( 1) emits a pulse, wherein the coding device (5) is further designed so that the instantaneous speed of the vehicle can be obtained as a first instantaneous measured variable value and the number of wheel rotations performed as a second instantaneous measured variable value using a system time from the measurement signal.

6. Radio link according to one of claims 1 to 4 for displaying the instantaneous heartbeat rate and the heartbeat variability of a living being, wherein the sensor is arranged in the region of the nervous system of the living being and as a measurement signal when a heartbeat is sensed at least one NEN pulse, wherein the coding device is further configured such that the current heartbeat rate as a first instantaneous measured variable value and the heartbeat variability as a second instantaneous measured variable value can be obtained from the measurement signal using a system time.

7. Radio link according to one of claims 1 to 4 for transmitting the information contained in the electrical pulses generated by a voltage-frequency converter, wherein the coding device is designed such that the instantaneous frequency of the electric pulses as a first instantaneous measured value and Number of pulses can be obtained as a second instantaneous measured value.

8. Use of a radio link according to one of claims 1 to 7.

9. A method for transmitting a measurement signal with a radio link, which has the following steps:

Generation of a large number of instantaneous values of a measurement signal,

Converting the instantaneous values into data packets of a data packet stream, a first instantaneous measured variable value and at least one second instantaneous measured variable value being obtained from the measured signal, and thereby data packets are generated which contain information about the first instantaneous measured variable value and data packets are generated , which contain information about the second instantaneous measured variable value or the second instantaneous measured variable values, sending out the data packets as a radio signal, receiving the data packets present as a radio signal, Convert the received data packets into measurement information, output of the measurement information.

10. A method for transmitting a measurement signal with a radio link according to claim 9, characterized in that

Data packets are generated that only contain information about the first instantaneous measured variable value, and that data packets are generated that only contain information about the second instantaneous measured variable value.

11. A method for transmitting a measurement signal with a radio link according to claim 9 or claim 10, characterized in that the information about the first instantaneous measured variable value and / or about the second instantaneous measured variable value is in each case distributed over a number of data packets.

12. A method for transmitting a measurement signal with a radio link according to one of claims 9 to 11, characterized in that the course of the measured variable represented by the first instantaneous measured variable values and / or by the second instantaneous measured variable values at times between reception and / or the conversion of data packets is estimated and output.

13. Transmitter, the at least one input for inputting a large number of instantaneous values of a measurement signal, a coding device connected to the input for converting the instantaneous values into data packets of a data packet stream and a transmission device for transmitting the data packets as a radio signal, the coding device being further designed so that a first instantaneous measured value value and at least one second instantaneous measured value value can be obtained from the measurement signal, wherein both data packets can be generated that contain information about the first instantaneous Contain measured variable value, and data packets can also be generated which contain information about the second instantaneous measured variable value or the second instantaneous measured variable values. ^■

14. Transmitter according to claim 13, characterized in that

Data packets can be generated that only contain information about the first instantaneous measured variable value, and that data packets can be generated that only contain information about the second instantaneous measured variable value.

15. Transmitter according to claim 13 or according to claim 14, characterized in that

Data packets can be generated, each of which has only part of the information about the first instantaneous measured value and / or about the second instantaneous measured value.

16. Receiver with a receiving unit for receiving data packets as a radio signal, with a decoding device for converting the received data packets into measurement information and with an output unit for outputting the measurement information, the decoding device being designed so that data packets contain the information about the contain the first instantaneous measured value ten, can be treated differently from data packets that contain information about the second instantaneous measured variable value.

17. Receiver according to claim 16, characterized in that the decoding device is designed such that information about the first instantaneous measured variable value and / or about the second instantaneous measured variable value can be obtained in each case from a plurality of data packets.

18. Receiver according to claim 17, characterized in that the output unit is designed such that the course of the measured variable represented by the first instantaneous measured variable values and / or by the second instantaneous measured variable values at times between the reception and / or the conversion of data packets can be estimated and output.