Method for communication between a terminal device and a mobile data collector via a short-range radio receiver, and short-range radio receiver

Description

[0001] The present invention relates, on the one hand, to a method for communication between a stationary terminal, in particular a consumption meter, and a mobile data collector via a short-range radio receiver according to the preamble of claim 1. Furthermore, the present invention relates to a short-range radio receiver according to the preamble of claim 14. Technological background

[0002] Terminal devices in a utility network, particularly consumption meters, e.g., for water, heat, gas, and energy, typically use the so-called M-Bus for communication. The M-Bus enables comprehensive networking of remote readings from a large number of heat meters, gas meters, water meters, and energy meters from different manufacturers. Comparatively small amounts of data per consumption meter are read at relatively long intervals, placing comparatively low demands on the transmission rate and thus also on energy consumption, since meters are typically powered by a single battery throughout their entire service life. Communication in the M-Bus can be either wired or wireless. Wireless M-Bus communication ("Wireless M-Bus") is regulated in more detail in the European standard CEN / TC294 EN13757-4.The Wireless M-Bus allows meters to be read by a mobile data collector driving through the supply area in which the meters are located and collecting the meter readings (drive-by reading).

[0003] According to EN13757-4, there are different operating modes for radio meter reading. Operating mode T (frequent transmission mode) and operating mode C (compact mode) are particularly suitable for reading while a data collector is driving past. In this case, the respective terminal device or meter transmits a very short telegram (usually 3-8 ms long) at intervals of a few seconds to enable the meter reading while the data collector is driving past. As soon as the data collector receives a telegram from the meter, a bidirectional communication structure is established in accordance with EN13757-4. The problem with this, however, is that due to the time required to establish communication, the data collector can only drive past the meter in question at a very low speed. Otherwise, there is a risk of communication failure.If the first reception window is missed, the data collector no longer has the opportunity to communicate with the meter. The meter only transmits again after a few seconds, e.g., after 10 seconds. Only then is communication possible again. This is not sufficient for a drive-by reading. Printed state of the art

[0004] The MBWBLUE brochure from Michael Rac GmbH, Ansbach, Germany, describes a portable bidirectional radio transceiver with a Bluetooth® interface for wireless M-Bus consumption meters. This radio transceiver is used for the mobile reception of M-Bus radio consumption meter telegrams and their further transmission to a portable computer via a Bluetooth interface. To receive data from a consumption meter in so-called drive-by mode, a bidirectional communication structure is first established with a consumption meter within range, in accordance with the wireless M-Bus. The radio transceiver sends a configured radio telegram when it has received a radio telegram from the respective consumption meter.The problem with this radio receiver is that for mobile meter reading, there must be an increased probability that a message from the radio receiver to the meter will reach its first reception window. However, this increased probability only exists at a very low drive-by speed.

[0005] US 2010 / 0007521 A1 concerns communication between a terminal device and a receiver using AM and FM communication. Object of the present invention

[0006] The object of the present invention is to enable bidirectional communication between data collectors and consumption meters at higher drive-by speeds. Solution to the task

[0007] The above object is achieved in the generic method by the features of claim 1 and in the generic short-range radio receiver by the features of claim 15. Advantageous embodiments of the respective invention are claimed in the dependent claims.

[0008] According to the invention, the short-range radio receiver determines the reception time at which the message arrives at the receiver. After receiving the command or command sequence from the data collector, the receiver determines the time of retransmission of the command or command sequence to the terminal device such that the command or command sequence is received by the terminal device within one or more reception windows. In particular, one command is transmitted within one reception window. This enables the receiver or data collector to calculate when the terminal device's next reception window will be. The receiver is therefore able to precisely schedule the transmission of commands from the data collector to the terminal device based on the location of the terminal device's reception window.

[0009] According to the invention, the determined reception time is transmitted from the receiver to the data collector or the receiver stores the reception time, i.e. does not transmit it further, and assigns it upon receipt of a command or command sequence from the data collector based on an identification (e.g. based on the meter address).

[0010] In particular, this opens up the possibility for the terminal device to receive a command or command sequence from the receiver within the reception window that the terminal device opens immediately after receiving the message. This is, so to speak, the "first possible" reception window for establishing communication. This results in the advantage that communication can be established much earlier than before, which in turn means that the data collector can move past the relevant terminal device at a higher speed.

[0011] In addition to the reception time, the receiver also conveniently determines the metadata of the message from the end device and transmits it to the data collector. Determining the metadata is also advantageous for the receiver or data collector to calculate the position of the end device's reception window.

[0012] The metadata may preferably be a signal strength and / or a particular transmission mode, in particular transmission mode T or transmission mode C or a bidirectional sub-mode of these transmission modes, and / or a frame format and / or a command validity time. These metadata, both individually and in combination, are advantageous with regard to the calculation of the position of the terminal's reception window by the receiver or data collector.

[0013] Accordingly, the receiver or data collector can determine the location of the next reception window based on the reception time and metadata.

[0014] According to the present invention, it can further be expediently provided that the reception time and / or the metadata is / are transmitted to the data collector together with the first message received by the receiver. The data collector thus receives this additional information very quickly together with the message from the terminal. After receiving the information, the data collector checks whether a command for the relevant terminal is present in its command buffer. The data collector then generates the data necessary to execute the command (e.g., application data, encryption of the data at the application layer or transport layer) and sends this data back to the receiver. Furthermore, the data collector sends, preferably with the aforementioned data, the reception time and the metadata, from which the receiver can determine the next reception window.

[0015] Alternatively, the data collector itself can calculate the position of the terminal's reception window and transmit it to the receiver. Knowing the reception window, the receiver can send the commands or command frames to the terminal via the primary interface in such a way that the terminal's reception window is reached. This enables very rapid establishment of communication with the terminal.

[0016] According to a further advantageous embodiment of the present invention, instead of a command or command sequence, the receiver can initially send a dummy command at the time of the determined reception window. This allows communication to be established even if the data collector needs some more time to generate the real command data, i.e., the first reception window(s) of the terminal device can be used to establish communication. Communication to the terminal device via the receiver can be maintained with a dummy command or dummy commands until "real command data" has been generated by the data collector and can be sent to the receiver. At this point, the receiver stops sending the dummy commands and replaces them with "real commands."

[0017] In particular, the transmission of dummy commands can be repeated via successively opened receive windows until the command or command sequence has been generated by the data collector and can be sent via the next receive window.

[0018] Preferably, the dummy command can be generated by the data collector and transmitted to the receiver, or the receiver simply receives a corresponding message from the data collector and then generates a dummy command itself.

[0019] According to a further advantageous embodiment, the data collector transmits commands belonging to a command sequence to the receiver in a single message. Furthermore, the short-range radio receiver can transmit commands belonging to a command sequence, preferably together with sequence information, to the data collector in a single message. This allows the volume of communication via the receiver to be reduced, thereby simplifying information processing in both the data collector and the receiver.

[0020] Preferably, the time period within which the terminal opens the receive window after sending the message is switchable, such that a first, longer time period and then a second, shorter time period can be generated in the terminal. After receiving a first command by the terminal, the first longer time period is switched to the second, shorter time period, and further communication takes place until the end of the command sequence while maintaining the second, shorter time period. This can accelerate the execution of a command sequence.

[0021] The short-range radio receiver is preferably a WPAN receiver, preferably a Bluetooth ®< receiver or a comparable receiver with a range of up to 100 m, preferably up to 300 - 500 m.

[0022] The method according to the invention makes it possible to effectively establish bidirectional communication while the data collector passes the terminal along a path at a speed of at least 40 km / h, preferably at least 45 km / h, particularly preferably at least 50 km / h.

[0023] The present invention further relates to a short-range radio receiver, preferably a WPAN receiver, particularly preferably a Bluetooth ®< receiver, according to the preamble of claim 14. To achieve the object according to the invention, the short-range radio receiver is designed such that it can be operated according to a method according to at least one of the preceding claims. Description of the invention using exemplary embodiments

[0024] Advantageous embodiments of the present invention are explained in more detail with reference to the drawing figures. These show: Fig. 1 shows a highly simplified schematic representation of the reading of terminal devices using a mobile data collector; Fig. 2 shows a highly simplified schematic representation of the interfaces between the terminal device, short-range radio receiver, and data collector according to the present invention; Fig. 3 shows a first embodiment of the method according to the invention for establishing communication between a moving data collector via a short-range radio receiver and a stationary terminal device; Fig. 4 shows a further embodiment of a method for establishing communication between a moving data collector via the short-range radio receiver and a stationary terminal device; and Fig. 5 shows a highly simplified schematic representation of the short-range radio receiver according to the present invention.

[0025] Fig. 1shows a plurality of terminal devices 1-1, 1-n, which can be stationary meters, in particular for water, gas, heat, or energy. The terminal devices 1-1, 1-n are operated in the so-called Wireless M-Bus according to EN13757-4. They therefore allow their meter readings to be read wirelessly, i.e., via radio, using a data collector 20, which in turn transmits the read data to a head-end 30. Transmission to the head-end 30 preferably takes place via the WAN network, in particular via the Internet. The meter data is further processed and managed in the head-end 30.

[0026] The terminal devices 1-1, 1-n are preferably operated in operating mode T or C. In these operating modes, the terminal devices 1-1, 1-n each transmit a very short message 3 or telegram, usually 3-8 ms long, to enable the meter reading to be read while walking and / or driving past. These messages 3 are continuously transmitted by the respective terminal device 1-1, 1-n, for example, at intervals of a few seconds, for example, at intervals of 8 s (see dashed arrows). If a corresponding message 3 is received by the data collector 20, communication can be established by transmitting a command or command sequence 4 from the data collector 20 to the respective terminal device 1-1, 1-n. As part of this communication, the meter data is transmitted to the data collector 20.

[0027] The data collector 20 is a mobile data collector that moves along a path W at a speed V past the individual terminals 1-1, 1-n and is designed to collect the meter readings as it passes. For this purpose, the data collector 20 is provided with a mobile base 11. The mobile base 11 can be a car, truck, or the like. For example, a corresponding data collector 20 can be housed in a vehicle that regularly passes through the relevant residential area. Suitable vehicles for this purpose include regularly passing garbage disposal vehicles, buses, or the like.

[0028] The data collector 20 is usually a standard device in the form of a PC, notebook or smartphone.

[0029] Furthermore, a short-range radio receiver 10 is provided to receive the messages 3 or telegrams from the terminal devices 1-1, 1-n and forward them to the data collector 20, or to receive commands or command sequences 4 from the data collector 20 and transmit them to the respective terminal device 1-1, 1-n. The short-range radio receiver 10 is capable of receiving the messages 3 or telegrams from the terminal device 1-1, 1-n in real time, i.e., with precise timing, in the ms range, and of sending commands or command sequences 4 accordingly to the terminal device 1-1, 1-n.

[0030] For this purpose, the respective terminal device 1-1, 1-n must have a communication module for Wireless M-Bus as well as a corresponding short-range radio module 12.

[0031] Out of Fig. 2An example of a corresponding communication structure is shown schematically. A bidirectional short-range radio interface 5 is provided between the data collector 20 and the short-range radio receiver 10. A bidirectional primary interface 6 or short-range radio interface is provided between the short-range radio receiver 10 and the respective terminal device 1-1, 1-n.

[0032] Fig. 3 shows an example of an expedient embodiment of the communication setup according to the invention based on a data exchange between the terminal 1-1, the short-range radio receiver 10 and the data collector 20 along the time axis (vertical in Fig. 3 ). For message 3 in Fig. 3This is a periodically, unsolicited message sent by terminal device 1-1 (telegram SND_NR). This message is received by short-range radio receiver 10, with the reception time RT and preferably also the metadata MD being determined by short-range radio receiver 10 and immediately forwarded to data collector 20.

[0033] The metadata MD includes in particular the signal strength, the transmission mode (T mode or C mode or sub-mode thereof), the frame format (M-Bus frame format: A or B) and / or the command validity time.

[0034] The data collector 20 then checks whether a command or command sequence 4 for the terminal device 1-1 is present in its buffer. The data collector 20 then generates the data required to execute the command or command sequence 4 (e.g., application data, data encryption at the application layer or transport layer) and sends it as a command sequence KS to the short-range radio receiver 10.

[0035] At the Fig. 3The command sequence 4 shown consists of the commands SND_UD, REQ_UD2, SND_NKE including the reception time RT and the metadata MD. The commands of command sequence 4 are standardized commands of EN13757-4. Accordingly, together with command sequence 4, the time RT of reception of message 3 and the metadata MD are transmitted back to the short-range radio receiver 10. It is now possible for the short-range radio receiver 10 to determine the position of the next reception window 2 of the terminal 1-1 from the available data, which Fig. 1 is opened in a time period ΔT of, for example, 1 s after sending the message 3. The short-range radio receiver 10 is thus able to transmit the command SND_UD (Send User Data) to the terminal 1-1 at the exact time within the reception window 2.

[0036] Furthermore, the short-range radio receiver 10 is able to determine the next reception window 2 of the terminal device 1-1 based on the data available to it. If the short-range radio receiver 10 receives the acknowledgment (ACK) from the terminal device 1-1, it transmits the REQ_UD2 command in the next reception window 2, to which the terminal device 1-1 responds with the RSP_UD message and the meter data (frames) are transmitted. The short-range radio receiver 10 transmits the meter data (frames) and the result of the command structure (KS) to the data collector 20. The SND_NKE command terminates communication between the terminal device 1-1, 1-n, and the data collector.

[0037] In an alternative embodiment, it is also possible for the position of the respective reception window 2 to be determined based on the reception time RT in the data collector 20 and for this information to be returned to the short-range radio receiver 10 so that the latter receives the information as to when exactly it must send the respective command.

[0038] After the SND_UD command, the terminal 1-1 switches from a slow response delay mode (formation of the reception window after ΔT, e.g., 1 s) to the so-called fast response delay mode (formation of a reception window after ΔT, e.g., 100 ms) based on the determination of the position of the first reception window 2. The short-range radio receiver 10 is Fig. 3 shown sequence example is able to send the command REQ_UD2 in fast response delay mode to the first receive window 2.

[0039] After receiving the last SND_NKE command within receive window 2 in fast response delay mode, communication is closed with the SND_NKE command. With the next message 3, the terminal 1-1 switches back to slow response delay mode. The next receive window 2 is thus generated within a period ΔT of, for example, 1 s after the transmission of message 3.

[0040] In this way, a very rapid establishment of communication between the terminal 1-1 and the data collector 20 can be ensured.

[0041] In the exemplary design of the procedure according to Fig. 4Another possibility for establishing communication according to the invention is possible in the event that the command sequence KS has not yet been created for the first reception window 2. The data collector 20 receives the message 3 together with the reception time RT and the metadata MD and determines that the command sequence KS is not yet available for the terminal 1-1, but that the reception window 2 is opened very shortly after the message 3 is sent (ΔT e.g., 100 ms).

[0042] In this case, the short-range radio receiver 10 first sends a so-called dummy command (SND_UD(Dummy)) in the first reception window 2 after the message 3. This dummy command is an empty command. The dummy command can already be generated in the data collector 20 and transmitted to the short-range radio receiver 10. Alternatively, instead of the dummy command, only information about the need for a dummy command can be transmitted to the short-range radio receiver 10. The dummy command serves to establish communication between the short-range radio receiver 10 and the terminal 1-1 as quickly as possible and to use the first reception window 2 for this purpose. The data collector 20 thereby gains time to generate the real command data. The transmission of a dummy command continues until the real command structure is available and the individual commands have been configured according to Fig. 3can be transmitted in the respective reception windows 2.

[0043] As from Fig. 3 and 4 As can be seen, the data collector 20 forwards the commands (e.g. SND_UD, REQ_UD2, SND_NKE) belonging to a command sequence to the short-range radio receiver 10 with a single message. Likewise, the short-range radio receiver 10 forwards commands belonging to a command sequence KS, preferably including the meter data, to the data collector 20 with a single message. This allows reduced communication via the interface of the short-range radio receiver 10 to be achieved. The short-range radio receiver 10 or the data collector 20 do not have to process individual commands or the response to a command of an ongoing communication. This simplifies processing in the data collector 20 and in the short-range radio receiver 10.

[0044] It is useful for a terminal 1-1, 1-n, which operates, for example, in T2 mode, to open its reception window in the slow response delay mode after, for example, ΔT 1 s and switch to the fast response delay mode (e.g., ΔT 100 ms) after sending message 2, as shown in Fig. 3 is visible. Further communication until the end of the sequence is then carried out in Fast Response Delay mode. This can accelerate the execution of a command sequence.

[0045] The short-range radio receiver 10 is a portable device that features a processor 14, a memory 15, and a self-sufficient power supply 16, preferably a rechargeable battery or a battery. Furthermore, the short-range radio receiver 10 features a short-range radio module 12 equipped with an antenna, as well as a communication module 13 for wireless M-Bus with an antenna. The communication interface between the short-range radio receiver 10 and the data collector 20 is wireless.

[0046] The short-range radio receiver 10 or WPAN receiver is preferably a receiver with a range of approximately 50-100 m. A Bluetooth ®< receiver can be provided for this purpose. In this case, interface 5 is configured as a Bluetooth ®< interface, and module 12 is configured as a Bluetooth ®< module.

[0047] The present invention enables an effective communication setup between a data collector 20 and a terminal 1-1, 1-n when the data collector 20 moves past at a speed of at least 40 km / h, preferably at least 45 km / h, particularly preferably at least 50 km / h.

[0048] The present invention therefore provides considerable advantages over the existing prior art with regard to the problem of establishing communication as quickly as possible between a moving data collector 20 and a stationary terminal 1-1, 1-n. LIST OF REFERENCE SYMBOLS

[0049] 1End device 2Receive window 3Message 4Command or command sequence 5Short-range radio interface 6Primary interface 10Short-range radio receiver 11Mobile base 12Short-range radio module 13Communication module for Wireless M-Bus 14Processor 15Memory 16Power supply 20Data collector 30Head-end ΔTTime span RTReception time KSCommand sequence MDMetadata

Claims

1. Method for communication between a terminal (1-1, 1-n) installed at a fixed location, in particular a consumption meter, and a mobile data collector (20), by using a Wireless M-Bus, via a short-range radio receiver (10), preferably a WPAN receiver, which sets up a bidirectional interface to the terminal (1-1, 1-n), which is situated in the reception range of the receiver (10), and transmits the data received from the terminal (1-1, 1-n) onward to the data collector (20) via a bidirectional short-range radio interface, wherein the terminal (1-1, 1-n) sends a message (3) periodically and unprompted for the purpose of communication set-up and in each case subsequently opens a reception window (2) after a period of time (ΔT), wherein in response thereto a command or a command sequence (KS) is conveyed from the mobile data collector (20) to the receiver (10) as the receiver (10) initially receives the command or the command sequence (KS) from the data collector (20) and conveys said command or command sequence to the terminal (1-1, 1-n) in the reception window (2), characterized in that the receiver (10) determines the reception time (RT) at which the message (3) arrives at the receiver (10), the receiver (10) transmits the reception time (RT) onward to the data collector (20), or the receiver (10) stores the reception time (RT) and assigns it on reception of a command or a command sequence (KS) on the basis of an identification, and the receiver (10), after having received the command or the command sequence (KS), including the reception time (RT), from the data collector (20) or having received the command or the command sequence (KS) from the data collector (20), stipulates the time at which the command or the command sequence (KS) is transmitted onward to the terminal (1-1, 1-n) while taking into consideration the reception time (RT), such that the command or the command sequence (KS) is received by the terminal (1-1, 1-n) within the reception window (2).

2. Method according to one of the preceding claims, characterized in that reception of the command or the command sequence (KS) from the receiver (10) by the terminal (1-1, 1-n) begins with that reception window (2) that is first opened by the terminal (1-1, 1-n) for the immediately preceding message (3), received by the receiver.

3. Method according to one of the preceding claims, characterized in that the receiver (10) takes metadata (MD) and transmits them onward to the data collector (20), the metadata (MD) in particular being a signal strength and / or a transmission mode, in particular the T mode or C mode, and / or a frame format, preferably MS-Bus frame format A or B, and / or a command validity period.

4. Method according to Claim 3, characterized in that the receiver (10) or the data collector (20) takes the reception time (RT) and / or the metadata (MD) as a basis for determining a position of the reception window (2).

5. Method according to Claim 3 or 4, characterized in that the reception time (RT) and / or the metadata (MD) is or are transmitted onward from the receiver (10) to the data collector (20) together with the message (3).

6. Method according to one of the preceding claims, characterized in that instead of a command or a command sequence (KS) a dummy command is initially sent from the receiver (10) to the terminal (1-1, 1-n) during the open reception window (2).

7. Method according to Claim 6, characterized in that the transmission of dummy commands over successively opened reception windows (2) is repeated until the command or the command sequence (KS) has been produced by the data collector (20) and can be sent over the reception window (2).

8. Method according to Claim 6 or 7, characterized in that the dummy command is produced by the data collector (20) and transmitted to the receiver (10), or the receiver (10) receives a message from the data collector (20) and then generates a dummy command.

9. Method according to one of the preceding claims, characterized in that the data collector (20) conveys commands that belong to a command sequence (KS), preferably together with the reception time (RT) and / or the metadata (MD), to the receiver (10) with a single message.

10. Method according to one of the preceding claims, characterized in that the receiver (10) conveys commands that belong to a command sequence (KS), preferably with process information, to the data collector (20) with a single message.

11. Method according to one of the preceding claims, characterized in that the period of time (ΔT) is switchable such that a first longer period of time or a second shorter period of time is generable in the terminal (1-1, 1-n), reception of a first command by the terminal (1-1, 1-n) is followed by a switch from the first longer period of time to the second shorter period of time, and the further communication is effected up to the end of the command sequence while retaining the second period of time.

12. Method according to one of the preceding claims, characterized in that the receiver (10) is a WPAN receiver, preferably a Bluetooth® receiver.

13. Method according to one of the preceding claims, characterized in that the bidirectional communication is effected while the data collector (20) passes the terminal (1-1, 1-n) at a velocity (V) of at least 40 km / h, preferably of at least 45 km / h, particularly preferably of at least 50 km / h.

14. Short-range radio receiver (10) comprising a communication module (13) for Wireless M-Bus having an antenna, a short-range radio module (12), preferably a WPAN module, a processor (14), a memory (15) and an energy source (16), preferably in the form of a battery or a storage battery, characterized in that the short-range radio receiver (10) is configured such that it is operable using a method according to at least one of the preceding claims.