Abstract:
A method for communication between a meter device and a communication network in accordance with a radio protocol, the meter device including a meter device identification and the radio protocol including a reduced part of the meter device identification and a data field, wherein the method of communication involves transmitting a data telegram according to the protocol from the meter device, receiving the data telegram by the communication network, and identifying the meter device from a set of identification elements, including the reduced part of the meter device identification and at least one information element obtained from a data source external to the meter device. The invention furthermore relates to an identification computer device and a meter device adapted for operating according to the above mentioned radio protocol, and a radio protocol for communication between a meter device and a communication network in accordance with the above mentioned radio protocol.

Description:
[0001]    The present invention relates to a radio protocol for communication between a meter device and a communication network, a meter device and a communication network for communicating according to the radio protocol, and a method communication according to the radio protocol. 
       BACKGROUND 
       [0002]    The invention is suitable for a remotely readable meter device, such as a meter device that measures the consumption of a q such as electricity, gas, heat, water, etc. and reports measurements to a central system via a communication network. Such meter devices may e.g. transmit data about the consumption or status of the meter device via the network at regular intervals or when receiving an initiating signal. The collection of data from the meter device may be done by a stationary network such as stationary antennas or by a mobile network comprising means for receiving data and means for storing or for transmitting data further, e.g. to a main location of the utility network system. 
         [0003]    The power source of remotely readable meter devices may be a battery, at least for commutating data. As one of the advantages of remotely readable meter devices is that they do not require on the spot service but can be read out remotely, it is important that such batteries have a sufficiently long lifetime, and therefore do not require service in the form of an unnecessary battery change. 
         [0004]    When a remotely readable meter device is communicating with a network by sending a data telegram according to a certain communication protocol, there are certain requirements to the communication protocol, i.e. to the contents of the data telegram. Such requirements may comprise at least establishment of synchronization between the sender and the receiver, identification of the meter, a checksum value for verification of the sent data, and a data field, which contains information about the consumption, operation, or status relating to the meter device. Furthermore, the protocol will usually contain more information, such as timing information, information about the length of the data telegram, information about the formatting of the data of the data field, information about the data fields, such as information about which quantity is measured, the unit it is measured in etc. The ratio between the actual information about the consumption, operation, or status, such as number and/or status bytes, and information that either does not relate directly to consumption, operation, or status, such as information about timing or information about measuring units, may be rather low. I.e. the numbers telling about the consumption, operation, or status may constitute a rather small amount of data compared to the full data telegram. 
         [0005]    It is known from EP 2088706 that when a meter device communicates a consumed quantity to a utility system by means of an MBUS data string including an identification of the meter, data record headers may be omitted. By using a checksum calculated over the full MBUS string including the data headers and including this checksum in the communication, the validity of the data record header assumed by the utility system may be tested. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0006]    The invention relates to a radio protocol for communicating data between a meter device and a communication network, said meter device being provided with a meter device identification for identifying said meter device, in which said radio protocol comprises:
       a reduced part of said meter device identification and   a data field, and
 
in which a full meter device identification of said meter device can be determined on the basis of a set of identification elements, said set of identification elements comprising at least:
   said reduced part of said meter device identification, and   at least one information element obtained from a data source external to said meter device.       
 
         [0011]    According to the above embodiment of the invention, the identification part of the radio protocol includes only a reduced part of the meter device identification. By excluding a part of the meter device identification, the data telegram sent from the meter device to the communication network according to the above embodiment will be shorter compared to a data telegram containing a full meter device identification. A shorter data telegram requires less energy to send. Therefore, for battery powered meter devices this shortening of the data telegram will increase the battery lifetime. This applies both to meter devices that are powered only by one or more batteries, but also to meter devices where at least the transmitting function is battery powered. An increased battery life is highly advantageous as it makes the need for battery changes less frequent or even completely unnecessary. Also, by keeping the data telegram as short as possible with respect to other elements, the battery lifetime is increased. However, when a data telegram is received by the communication network, it still needs to be identified. This identification cannot take place solely on the basis of the reduced part of the meter device identification as more than one meter device may have matching reduced parts of their meter device identifications. Therefore, also at least one identification element obtained from a data source external to said meter device is used in the identification process together with the reduced part of the meter device identification. 
         [0012]    A meter device identification is generally to be understood as a piece of information that uniquely identifies the meter device. The meter device identification could e.g. be an identification number, but may also be understood as a sequence of characters such as numbers, letters or other symbols. Numbers are to be understood as any kind of number regardless of representations or bases such as 10-digit Arabic numbers, hexadecimals, binary numbers, bit sequences, or other numbers. 
         [0013]    According to an embodiment of the invention, said radio protocol furthermore comprises at least one information element, 
         [0000]    said set of identification elements furthermore comprises said at least one information element of the radio protocol, and
 
said at least one information element obtained from a data source external to said meter device comprises at least information relating to said at least one information element of the radio protocol.
 
         [0014]    An advantage of this embodiment may be that by including information elements comprised in the radio protocol, i.e. comprised in the data telegram that is sent from the meter device to the communication network, and information relating to this coming from the data source external to the meter device in the set of identification elements that provides the basis for identification, a more certain identification can be carried out. Examples of information elements are given in the below embodiments, however, any information element comprised in the radio protocol, i.e. in the data telegram, may be used to identify the sender meter device. This may in a preferred embodiment be done by comparing with a priori knowledge about such information elements, such as data in a database. 
         [0015]    According to an embodiment of the invention, said 
         [0000]    at least one information element of the radio protocol comprises at least a checksum established on the basis of at least:
       said meter device identification, and   said data field of the radio protocol.       
 
         [0018]    An advantage of this embodiment may be that by including a checksum value comprised in the radio protocol, i.e. comprised in the data telegram that is sent from the meter device to the communication network in the set of identification elements that provides the basis for identification, a more certain identification can be carried out. There is made no distinction between a checksum and a hash sum as these are considered to be equivalent. 
         [0019]    In another embodiment of the invention, the checksum is established on the basis of a reduced part of the meter device identification, said reduced part of the meter device identification containing a part of the meter device identification that is not contained on the radio protocol or the data telegram. 
         [0020]    According to an embodiment of the invention, said checksum is a Cyclic Redundancy Check (CRC) sum. According to alternative embodiments, however, this checksum may be other checksums such as Fletcher&#39;s checksum, Adler-32 checksum, or a modular checksum. 
         [0021]    According to an embodiment of the invention, said at least one information element obtained from a data source external to said meter device comprises at least information about meter device identifications. 
         [0022]    An advantage of this embodiment may be that by including information about meter device identifications in the at least one information element obtained from a data source external to said meter, it is possible to have a more certain identification. This could in an embodiment be e.g. by comparing or correlating the reduced part of the meter device identifications of the radio protocol with the above mentioned information about meter device identifications. Thereby, it can be determined which of the meter device identifications that are in agreement with the reduced part of the meter device identification. 
         [0023]    According to an embodiment of the invention, the validity of said data field can be determined on the basis of:
       said checksum,   said data field, and   said information about meter device identifications.       
 
         [0027]    An advantage of the above mentioned embodiment of the invention may be that it can be determined from the checksum value if there are any errors in the data telegram. I.e. if such errors are present, the checksum value can reveal them. This may e.g. be done by comparing or correlating said checksum calculated on the basis of said data field and said information about meter device identifications. Thereby, it is avoided that wrongful information from a corrupted data telegram is registered. Such wrongful information may for a utility meter device lead to e.g. errors in the consumption of the consumer, which may have negative economic consequences for the consumer and/or the utility company. 
         [0028]    According to an embodiment of the invention, the radio protocol comprises a first and a second checksum, said first checksum being established on the basis of at least:
       the full meter device identification   the data field,   said second checksum being established on the basis of the content of the radio protocol. According to this embodiment, the first checksum is particularly suitable for identifying the sender meter device, and the second checksum is particularly suitable for testing the validity of the transmitted data telegram.   According to this embodiment, the basis for establishing the first checksum may also comprise timing data such as a time stamp, or other redundant information such as information about the length of the data telegram, information about the data fields, synchronization word, or other header information.       
 
         [0033]    According to an embodiment of the invention, said at least one information element of the radio protocol comprises at least timing data, said timing data being established on the basis of an internal timing function of said meter device, and said at least one information element obtained from a data source external to said meter device comprises information relating to said at least one information element of the radio protocol, said information comprises at least information relating to said internal timing function of said meter device. 
         [0034]    An advantage of the above embodiment is that by including timing data comprised in the radio protocol, i.e. comprised in the data telegram that is sent from the meter device to the communication network and information or a priori knowledge about internal timing of meter device, in the set of identification elements that provides the basis for identification, a more certain identification can be carried out. 
         [0035]    According to an embodiment of the invention, said at least one information element of the radio protocol comprises at least a synchronization word for synchronizing communication between said meter device and said communication network, and said at least one information element obtained from a data source external to said meter device comprises information relating to said at least one information element of the radio protocol, said information comprises at least information relating to said synchronization word of said meter device. 
         [0036]    An advantage of the above embodiment may be that by including a synchronization word comprised in the radio protocol, i.e. comprised in the data telegram that is sent from the meter device to the communication network and information or a priori knowledge about synchronization words of meter device, in the set of identification elements that provides the basis for identification, a more certain identification can be carried out. 
         [0037]    According to an embodiment of the invention, said at least one information element obtained from a data source external to said meter device comprises at least information established at least partly on the basis of data fields of previous communication. 
         [0038]    An advantage of the above embodiment may be that information about the consumption contained in the data field can be compared with already known information about consumption relating to different meter devices that have previously been received. In an example embodiment, the meter device is a utility meter and measures at least e.g. consumption of water. By comparing a received data field containing a measure of the water consumption with historic data of water consumptions relating to different meter devices, some meter devices can be ruled out. More specifically, meter devices where historic data reveals a water consumption that is greater than the water consumption of the newly received data telegram can be ruled out. This applies for all embodiments where meter devices transmit a cumulative consumption as the consumption may not reverse, i.e. a meter device readout will always be at least the same as the previous readout of the same meter device. In another example embodiment, the meter device measures at least an instantaneous value. To compare with the above example embodiment, this could e.g. be the instantaneous water flow. In an embodiment, such information may also be used to rule out certain meter devices. This could e.g. be if there is a limit, such as a technical limit, to how large the instantaneous water flow can be. Then the instantaneous water flow may be compared with a priori knowledge about maximum instantaneous water flow for possible meter devices. If the received data telegram contains information about an instantaneous water flow larger than the maximum of some meter devices, these meter devices can be ruled out as possible sender meter devices. However, in some embodiments, the consumption level of a meter device may be reset. In such embodiments, information about this reset must be included for the above embodiment to work. 
         [0039]    According to an embodiment of the invention, said set of identification elements furthermore comprises at least one communication information element, said at least one communication information element being established at least partly on the basis of said communication between said meter device and said communication network, and said at least one information element obtained from a data source external to said meter device comprises at least information relating to said communication between said meter device and said communication network. 
         [0040]    According to an embodiment of the invention, said communication network comprises an antenna for receiving said data telegram, said at least one communication information element comprises at least a location, said location being established at least partly on the basis of the location of said antenna, and said at least one information element obtained from a data source external to said meter device and relating to said communication between said meter device and said communication network, comprises at least information about locations of said meter devices. 
         [0041]    An advantage of the above embodiment may be that by including a location of or relating to a receiving antenna and information or a priori knowledge about locations of antennas and/or meter devices in the set of identification elements that provides the basis for identification, a more certain identification can be carried out. In some embodiments, the information or a priori knowledge of locations of antennas and/or meter devices may be requested from a database, and a comparison between the location of the receiving antenna may be made. However, in other embodiments, it may be an advantage that the selection according to the position of the receiving antenna is made by having a local database at the antenna, where this local database contains only information about meter devices from which it may receive data telegrams. Hereby, locational data is taken into account when determining which meter device that has sent the data telegram. If the antenna is mounted on a vehicle or otherwise works as a mobile antenna, i.e. the position of the antenna may vary substantially, a local database may be established by transferring data to a data processing unit in the vehicle where the selection of the transferred data is made on the basis of a planned route of the vehicle. 
         [0042]    According to the above embodiment, said at least one information element obtained from a data source external to said meter device relating to said communication between said meter device and said communication network comprises information about locations of meter devices. However, in alternative embodiments, the location of the receiving antenna is determined and compared with known antenna locations e.g. according to a database. This embodiment applies only to stationary antennas as the location of a mobile antenna may not be known a priori. In the broadest embodiment, a location in relation to a receiving antenna is compared to a known location characteristic of the meter device. 
         [0043]    According to an embodiment of the invention, the receiving signal strength of the antenna may be used when determining the sender meter device. When receiving a data telegram from a meter device, which is close to the antenna, the signal strength will typically be higher than if the meter device is further away from the antenna. In one embodiment, the signal strength is compared with historical data about signal strengths for different meter devices in order to determine the sender meter device. 
         [0044]    According to an embodiment of the invention, said at least one communication information element comprises at least information about a communication channel used for communication between said meter device and said communication network, and said at least one information element obtained from a data source external to said meter device relating to said communication between said meter device and said communication network, comprises at least information about meter device communication channels. 
         [0045]    An advantage of this embodiment may be that by including information about a communication channel relating to the transmission from the meter device and information or a priori knowledge about communication channels of meter devices, in the set of identification elements that provide the basis for identification, a more certain identification can be carried out. 
         [0046]    According to an embodiment of the invention, said full meter device identification of said meter device can be determined on the basis of said set of identification elements, and said at least one information element obtained from a data source external to said meter device can be compared with at least a part of the rest of said set of identification elements. According to this embodiment, it may be advantageous to obtain said full meter device identifications on the basis of said comparison. 
         [0047]    According to an embodiment of the invention, said at least one information element obtained from a data source external to said meter device comprises at least an information list, and said data source external to said meter device is a database. 
         [0048]    An advantage of this embodiment may be that by storing a priori knowledge of meter devices in an information list in a database, these are readily available and may be organized and stored in an advantageous way. In some embodiments of the invention, the database may be a central database containing information about all meter devices of the utility company. However, in other embodiments, it may be a local database containing only information about a limited number of meter devices. This local database could in an example embodiment be placed together with a receiving antenna and only contain information about meter devices from which the antenna receives data telegrams. 
         [0049]    According to an embodiment of the invention, said reduced part of said meter device identification is one byte of said meter device identification. 
         [0050]    According to an alternative embodiment, said reduced part of said meter device identification is two bytes of said meter device identification. 
         [0051]    An advantage of sending a reduced data telegram compared to data telegrams suggested by prior art may be that it is harder to break the encryption of the data telegram. As the information in the data telegrams are typically consumer specific and sensitive, data telegrams are typically encrypted in order to make them unreadable to third party receivers. Redundant information makes it easier to break this encryption as it is often similar or the same for different meter devices. Therefore, it is an advantage of an embodiment of the invention that information that is non-specific to the meter device is limited in the data telegram. Another advantage of reducing redundant information in the data telegram is that a reduced and therefore shorter data telegram can be transmitted over a longer distance using the same transmission strength. This is because the package error rate (PER) increases with a longer data telegram, i.e. with more bits. The PER also increases with increasing bit error rate (BER), and the BER increases with longer transmission distance. Therefore, by reducing the length of the data telegram, the transmission distance may be increased without increasing the PER. 
         [0052]    According to an embodiment of the invention, an identification computer device is adapted for receiving a data telegram from a meter device according to a radio protocol, said radio protocol comprising at least:
       a reduced part of said meter device identification and   a data field, and
 
said identification computer device is adapted to perform a full meter device identification of said meter device from which said data telegram is received on the basis of a set of identification elements, said set of identification elements comprising at least:
   said reduced part of said meter device identification, and   at least one information element obtained from a data source external to said meter device.       
 
         [0057]    According to an embodiment of the invention, an identification computer device according to the above embodiment may comprise any combination of the features of the above embodiments of the radio protocol. 
         [0058]    According to an embodiment of the invention, a meter device is adapted for operating in accordance with a radio protocol for communicating data between said meter device and a communication network, said meter device is being provided with a meter device identification for identifying said meter device, 
         [0000]    wherein said radio protocol comprises at least:
       a reduced part of said meter device identification and   a data field, and
 
wherein a full meter device identification of said meter device can be determined on the basis of a set of identification elements, said set of identification elements comprising at least:
   said reduced part of said meter device identification, and   at least one information element obtained from a data source external to said meter device.       
 
         [0063]    According to an embodiment of the invention, a meter device according to the above embodiment may comprise any combination of the features of the above embodiments of the radio protocol or identification computer means. 
         [0064]    According to an embodiment of the invention, a method for communication between a meter device and a communication network in accordance with a radio protocol for communicating data between a meter device and a communication network said meter device is being provided with a meter device identification for identifying said meter device, 
         [0000]    wherein said radio protocol comprises:
       a reduced part of said meter device identification, and   a data field,
 
wherein said method of communication comprises the steps of:
   transmitting a data telegram according to said protocol from said meter device,   receiving said data telegram by said communication network, and   identifying said meter device
 
wherein said step of identifying said meter device is performed on the basis of a set of identification elements, said set of identification elements comprising at least:
   said reduced part of said meter device identification, and   at least one information element obtained from a data source external to said meter device.       
 
         [0072]    According to an embodiment of the invention, a method for communication between a meter device and a communication network according to the above embodiment may comprise any combination of the features of the above embodiments of the radio protocol, identification computer means, or meter device. 
         [0073]    An advantage of one embodiment of the invention is that the protocol uses a priori knowledge to minimize the communication needed between the meter device and the communication network. A communication with minimized amount of data being exchanged between the meter device and the communication network leads to a minimized power consumption, which in turn leads to a longer battery life. Such a priori knowledge may lead to much of the data otherwise transmitted from the meter device being redundant. Such redundant data may e.g. be a part of a meter device identification number, time stamp or timing information, format of the telegram, length of the telegram, etc. 
         [0074]    The invention furthermore relates to a method for communication between a meter device and a communication network in accordance with a radio protocol for communicating data between a meter device and a communication network, said meter device being provided with a meter device identification for identifying said meter device, wherein said radio protocol comprises:
       a reduced part of said meter device identification and   a data field,
 
wherein said method of communication comprises the steps of:
   transmitting a data telegram according to said protocol from said meter device,   receiving said data telegram by said communication network, and   identifying said meter device
 
wherein said step of identifying said meter device is performed on the basis of a set of identification elements, said set of identification elements comprising at least:
   said reduced part of said meter device identification, and   at least one information element obtained from a data source external to said meter device.       
 
         [0082]    According to an embodiment of the invention, said radio protocol furthermore comprises at least one information element, said set of identification elements furthermore comprises said at least one information element of the radio protocol, and said method furthermore comprises the step of
       obtaining said at least one information element comprising at least information relating to said at least one information element of the radio protocol from a data source external to said meter device.       
 
         [0084]    According to an embodiment of the invention, said at least one information element of the radio protocol comprises at least a checksum, and wherein said method furthermore comprises the steps of
       establishing said checksum on the basis of at least:   said meter device identification of the radio protocol, and   said data field of the radio protocol.       
 
         [0088]    According to an embodiment of the invention, said checksum is a Cyclic Redundancy Check (CRC) sum. 
         [0089]    According to an embodiment of the invention, said method furthermore comprises the step of
       obtaining said at least one information element comprising at least information about meter device identifications from a data source external to said meter device.       
 
         [0091]    According to an embodiment of the invention, said method furthermore comprises the steps of
       determining the validity of said data field on the basis of:   said checksum,   said data field, and   said information about meter device identifications.       
 
         [0096]    According to an embodiment of the invention, said at least one information element of the radio protocol comprises at least timing data, wherein said information relating to said at least one information element of the radio protocol comprises at least information relating to an internal timing function of said meter device, and said method furthermore comprises the step of
       establishing said timing data on the basis of said internal timing function of said meter device.       
 
         [0098]    According to an embodiment of the invention, said at least one information element of the radio protocol comprises at least a synchronization word, said information relating to said at least one information element of the radio protocol comprises at least information relating to said synchronization word of said meter device, and said method furthermore comprises the step of
       synchronizing communication between said meter device and said communication network by means of said synchronization word.       
 
         [0100]    According to an embodiment of the invention, said method furthermore comprises the step of
       obtaining at least one information element comprising at least information established at least partly on the basis of data fields of previous communication from a data source external to said meter device.       
 
         [0102]    According to an embodiment of the invention, said set of identification elements furthermore comprises at least one communication information element, said method furthermore comprises the step of
       establishing said at least one communication information element at least partly on the basis of said communication between said meter device and said communication network, and
 
said at least one information element obtained from a data source external to said meter device comprises at least information relating to said communication between said meter device and said communication network.
       
 
         [0104]    According to an embodiment of the invention, said communication network comprises an antenna receiving said communication, said at least one communication information element comprises at least a location, said method furthermore comprises the step of
       establishing said location at least partly on the basis of the location of said antenna, and
 
said at least one information element relating to said communication between said meter device and said communication network comprises at least information about said location of said antenna.
       
 
         [0106]    According to an embodiment of the invention, said method furthermore comprises the step of
       using a communication channel for communication between said meter device and said communication network,
 
said at least one communication information element comprises at least information about said communication channel, and said at least one information element relating to said communication between said meter device and said communication network comprises at least information about said communication channel.
       
 
         [0108]    According to an embodiment of the invention, said method furthermore comprises the steps of
       determining a full meter device identification of said meter device on the basis of a set of identification elements, and   comparing said at least one information element obtained from a data source external to said meter device with at least a part of the rest of said set of identification elements.       
 
         [0111]    According to an embodiment of the invention, said method furthermore comprises the steps of
       receiving an information list from a database, and   obtaining at least one information element comprising at least said information list from a data source external to said meter device.       
 
         [0114]    According to an embodiment of the invention, said reduced part of said meter device identification is one byte of said meter device identification. 
         [0115]    According to an embodiment of the invention, said reduced part of said meter device identification is two bytes of said meter device identification. 
         [0116]    It is noted that all of the above mentioned embodiments may be combined in any way to give new embodiments. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0117]    An embodiment of the present invention will in the following be described with reference to the drawing in which: 
           [0118]      FIG. 1  illustrates a data telegram according to prior art and a data telegram according to an embodiment of the invention, 
           [0119]      FIG. 2  illustrates the communication between the meter device, the communication network, the identification computer means, and the database according to an embodiment of the invention, 
           [0120]      FIG. 3  illustrates an example of a data telegram according to an embodiment of the invention, 
           [0121]      FIG. 4  illustrates the identification process according to an embodiment of the invention, 
           [0122]      FIG. 5  illustrates the communication between multiple meter devices and two stationary antennas according to an embodiment of the invention, 
           [0123]      FIG. 6  illustrates the communication between multiple meter devices and a mobile antenna according to an embodiment of the invention, 
           [0124]      FIG. 7  illustrates a meter device according to an embodiment of the invention, and 
           [0125]      FIG. 8  illustrates an example of a data telegram according to an embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0126]    Referring to  FIG. 1 , a full data telegram  111  is shown with a reduced data telegram  112 . The full data telegram  111  comprises a header  104 , a complete data field  106 , a first checksum  101 , and a second checksum  102 . The header comprises a synchronization word  86 , a meter device identification  83 , a length of the data telegram  103 , timing data  85 , and redundant information  105 . The complete data field  106  comprises data information fields  107 , and data fields  62 . The data fields  62  comprises information such as information concerning the consumption or status of the meter device. According to an embodiment of the present invention, the reduced data telegram  112  comprises a synchronization word  86 , a reduced part of meter device identification  84 , a part of timing data  110 , several data fields  62 , a first checksum  101 , and a second checksum  102 . The reduced part of meter device identification  84  is a reduced part of the meter device identification  83 , such as one byte of the meter device identification  83 . The part of timing data  110  is a part of the timing data  85 , such as one byte of the timing data  85 . The first checksum  101  is calculated on the basis of the complete set of information  108 . The second checksum  102  is calculated on the basis of the data telegram that is sent. I.e. if the full data telegram  111  is sent, the first checksum  101  and the second checksum  102  are equal. According to EP 2088706, the data information fields may be omitted. Then the first checksum  101  is calculated on the basis of a complete set of information  108  comprising the header  104  and complete data field  106  of the full data telegram  111 , including the data information fields  107 . By calculating the first checksum  101  on the basis of the complete set of information  108 , it is possible to check the matching of assumed information paired with the reduced set of information  109  which is performed by the receiver of the reduced data telegram  112 . By calculating the second checksum  102  on the basis of the reduced set of information  109 , i.e. on the reduced data telegram  112  which is actually sent, it is possible to verify if any errors in the data telegram  112  has occurred. 
         [0127]    Referring to  FIG. 2 , a simple illustration of the identification process according to an embodiment of the invention is shown. On  FIG. 2 , a meter device  1 , identification computer means  73 , and a database  70  are seen. The identification computer means  73  may receive information from the meter device  1  in the form of a data telegram  60 , an example of which is shown on  FIG. 3 . The data telegram  60  is received by a communication network  75 . The identification computer means  73  may receive data telegrams from multiple other meter devices not shown in  FIG. 2 . The example of a data telegram  60  shown on  FIG. 3  according to the radio protocol according to the present invention comprises a reduced part of an identification number  61 , a data field  62 , and a checksum  63 . The database  70  in  FIG. 2  contains meter device identifications, preferably in the form of meter device identification numbers, and other information elements. Such other information elements may be one or more of e.g. meter device synchronization words, meter device timing data, meter device radio channel, or other information usable for identification of the sender meter device  1 . Since the data telegram  63  contains only a reduced part of an identification number  61  and not a full identification number  74 , the full identification number  74  must be constructed. According to this preferred embodiment, the meter device  1  transmits a data telegram  60  to the identification computer means  73 . When the identification computer means  73  receives the data telegram  60 , containing a reduced part of the identification number  61  and other information elements, it sends a request for a list of identification and information elements  71  to the database  70 . This may comprise all identification numbers in the database  70 , or it may be for a limited set of identification numbers, the limited set being determined on the basis of the part of an identification number  61  and/or information elements contained in the data telegram  60 . In some embodiments, the database  70  contains only data for a limited number of meter devices, e.g. when the database  70  is locally placed e.g. at the antenna. The list of identification elements  71  may contain, in addition to identification numbers, information elements. On the basis of the reduced part of the identification number  61  contained in the data telegram  60 , the list of identification and information elements  71  received from the database  70 , and possibly one or more information elements deduced from the communication between the meter device  1  and the communication network  75 , the identification computer means  73  determines the full identification number  74  of the sender meter  1 , from which the data telegram  60  has been transmitted. Such deduced identification elements may be one or more of e.g. a location of the meter device  1  and/or the antenna of the communication network  75 , a communication channel, signal strength, or other identification elements or information deducible from the communication between the meter device  1  and the communication network  75  and which may be different for different meter devices. An important teaching of  FIG. 2  is that a full identification is performed partly on the basis of at least one identification element received from the meter, here being a part of an identification number  61 , and partly on the basis of a list of identification numbers requested from a database. 
         [0128]    Referring to  FIG. 4 , an embodiment of the invention is illustrated. All identification numbers  54  of the database  70  are shown as a circle illustrating the set of identification numbers  54  contained in the database  70 . Using different information elements, which alone are not sufficient to make a complete identification, the identification is carried out. Each information element reduces the number of identification numbers in the database  70  that are consistent with the given information element. As more information elements are taken into account, the number of possible sender meter devices reduces leaving only a single possible identification number  58  after a sufficient number of information elements have been applied. In an example embodiment, the location of the receiving antenna of the communication network  75  is combined with database information about location of the individual meter devices, giving a limited number of identification numbers  55  matching this location information. There are also a limited number of identification numbers  56  in the database  70  that has the correct part of an identification number  61 . Finally, there are a limited number of identification numbers  57  in the database that combined with the data field  62  of the data telegram  60  gives the correct checksum  63 . Combining two of the information elements will limit the number of possible identification numbers even further, but according to this example embodiment this will not be enough to reduce the possible identification numbers to only one. This is illustrated as the intersection of any two circles representing the sets of identification numbers  55 ,  56 , and  57  on  FIG. 4 . According to this example embodiment, it is necessary to combine three identification elements in order to achieve a full identification, i.e. to have one and only one identification number  58  matching all of the used information elements. In other embodiments of the invention, it may be sufficient to use only one or two information elements, whereas in yet other embodiments of the invention, it may be necessary to use more than three information elements, such as four, five, six or more information elements. In some embodiments, it may be advantageous to perform the identification steps mentioned above in a certain order in order to minimize the need of processing power and in order to give the fastest identification. I.e. it may be advantageous to use the information elements in a certain order. This could mean that e.g. location data is the first information element that is used. Also, information about communication channel may be used relatively early, e.g. in the second step. On the other hand, checksum data may be used as the last information element, as it requires some data processing power to calculate possible checksum values, especially if the number of possible meter device identifications is high. 
         [0129]    Referring to  FIG. 5 , an example embodiment of the invention is illustrated. In this example embodiment, a number of meter devices  1 - 7  and stationary antennas  20  and  21  are illustrated. The range  30  of the stationary antenna  20  is illustrated by a circle  30 , as is the range  31  of antenna  21 . In real life, the range will be influenced by a number of factors, such as height difference of ground level, buildings, reflections etc. For illustrative purposes, a simplified model is presented showing a circular range. Each of the meter devices  1 - 7  is provided with a meter device antenna  10 . The meter devices  1 - 7  will each transmit a data telegram  11 - 17  comprising a reduced part of an identification number  61 , in this example embodiment the last byte of their identification number. The data telegrams  11 - 17  furthermore comprise at least a data field corresponding to the consumption measured by each of the meter devices  1 - 7 , and a checksum. As illustrated in  FIG. 2 , meter devices  1 - 5  are within the range  30  of stationary antenna  20 , but out of range  31  of antenna  21 , whereas meter devices  6 - 7  are out of range  30  of stationery antenna  20  but in range  31  of antenna  21 . This means that the data telegrams  11 - 15  transmitted by meter devices  1 - 5  will be received by antenna  20 , while data telegrams  16 - 17  transmitted by meter devices  6 - 7  will be received by antenna  6 - 7 . The received data telegrams  11 - 17  then sent from the antennas  20 ,  21  to identification computer means  73  for identification. Each of the meter devices  1 - 7  is provided with a unique meter device identification number, as listed in table 1. The identification numbers according to this example embodiment consists of three bytes, i.e. three numbers between 0 and 255. When each of the meter devices  1 - 5  transmit a data telegram  11 - 15  to the stationary antenna  20  according to this embodiment of the invention, they will only transmit the last byte of their identification number. This is according to table 1 sufficient to uniquely identify data telegrams  13 - 15  and  17  coming from meter devices  3 - 5  and  7 , as the last byte of the identification numbers of these meter devices are unique, i.e. different from all the other last bytes. According to table 1, meter devices  1 ,  2 , and  6  have a common identification number where the last byte is 8. Therefore, additional information is needed in order to identify the meter device from which each of the received data telegrams  11 ,  12 , and  16  has been sent. The identification numbers of the meter devices  1 - 7  are in this example embodiment listed in a database  70 . In this embodiment, the database also comprises information for each of the meter devices  1 - 7  from which antenna  20  or  21  is able to receive a transmission. Such location knowledge may e.g. be obtained when installing the meter devices  1 - 7 , or from previous communications. In other embodiments, the correlation between meter devices  1 - 7  and antennas  20 - 21  may be calculated from a position of meter devices  1 - 7  and antennas  20 - 21 , by means of e.g. computer software. Such software may in some embodiments take further information into account, such as information about terrain, buildings, weather, earlier measurements etc. Also, in some embodiments, it is possible that a data telegram is received by more than one antenna, and that such information may be used to provide a more exact location of the sender meter device. In this simple example embodiment, however, only antenna  20  is listed for meter devices  1 - 5  in the database, whereas only antenna  21  is listed for meter devices  6 - 7 . 
         [0130]    By comparing information about which of the antennas  20 ,  21  that has received a data telegram with information from the database, it is possible to limit the number of possible sender meter devices. According to this example embodiment, it may with such knowledge be determined that the meter device, for which the value of the last byte  61  is 8 and which is communicating with antenna  21 , must be meter  6 . 
         [0131]    However, the meter devices, which have an identification number last byte  61  being 8 and which are communicating with antenna  20 , may be either of meter devices  1  or  2 . So, by combining the location knowledge with received identification byte, it is in this example possible to uniquely identify meter devices  3 - 7 , whereas identification of meter devices  1 - 2  is not possible without additional information. Additional information may in this example embodiment be a checksum, such as a Cyclic Redundancy Check (CRC) sum, which is transmitted as a part of the data telegram  60 . The transmitted checksum may be compared with possible checksums calculated by identification computer means  73  from data field  62  of the data telegram  60  and the possible identification numbers of meter devices  1 - 2 . By comparing the calculated checksums with the transmitted checksum, it is possible to identify the correct combination of data filed  62  and identification number if possible meter devices  1 - 2 , i.e. to identify the meter device  1  or  2  which has sent the data telegram  60 . Furthermore, if the checksum may still be used to check the validity of the data telegram  60  or the data field  62 . If none of the possible identification numbers gives the correct checksum, this indicates a corrupted data telegram  60  or data field  62 . To sum up, in this example, this means that data telegrams  11 - 15  received by antenna  20 , may only correspond to meter devices  1 - 5 , as these are known to be the only meter devices able to transmit to antenna  20 . Furthermore, each the last byte of meter device identification numbers from meter devices  3 - 5  is unique thereby identifying the sender meter device  3 - 5  of these data telegrams  13 - 15 . Finally, the sender meter device  1  or  2  of the data telegrams  11 - 12  is identified by calculating the checksum from the possible combinations of possible identification number and the data field  62  of each data telegram  11 - 12 , and comparing with the checksum of data telegrams  11 - 12 . Only the combinations of data fields and identification numbers giving a checksum corresponding to the checksum received in the same data telegram  11  or  12  as the data field  62 , from which it is calculated, will be the correct combinations, thereby identifying the sender meter devices  1  or  2 . In some embodiments it may be advantageous to use consumption data, such as the consumption data listed in table 1. For example, if data telegram  12  from meter device  2  is received by the communication network, the consumption is 16 in a certain unit as listed in table 1. This could e.g. be 16 cubic meters of water consumption. It may in an example embodiment then be so that it is known that the previous measured consumption of meter device  1  was e.g. 19, the previous measured consumption of meter device  2  was 12, and previous measured consumption of meter device  6  was 49. Then combining last byte  8  of identification number and knowledge about previous consumption of corresponding meter devices  1 ,  2 , and  6  with the measured value 16 gives the conclusion that the data telegram must come from meter device  2  as the consumption may not reverse, i.e. it is cumulative. The data telegram may in some embodiments contain more data fields, where some may be cumulative and some may not, e.g. a cumulative consumption, and an instantaneous flow rate. 
         [0000]    
       
         
               
               
               
             
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                 Meter  
                   
                   
               
               
                 device 
                 ID 
                 Consumption 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 111.245.8 
                 23 
               
               
                 2 
                 89.3.8 
                 16 
               
               
                 3 
                 209.49.102 
                 3 
               
               
                 4 
                 29.102.221 
                 89 
               
               
                 5 
                 34.190.90 
                 0 
               
               
                 6 
                 67.44.8 
                 62 
               
               
                 7 
                 72.234.66 
                 5 
               
               
                   
               
             
          
         
       
     
         [0132]    Referring to  FIG. 6 , another example embodiment of the invention is shown. In this example, a number of meter devices  1 - 7  each with their own antenna  10  are transmitting data telegrams  11 - 17 . A moving vehicle  51  is provided with an antenna  22  for receiving data telegrams  11 - 15  from meter devices  1 - 5  within range  32  and a positioning unit  52  for receiving a positioning signal from one or more positioning satellites  50  and determining a position of the vehicle  51  on the basis thereof. Since the antenna  22  is placed on a vehicle  51  which is mobile, it functions as a mobile antenna  22 . The receiving range  32  of the mobile antenna  22  is illustrated by a circle. 
         [0133]    As for  FIG. 2 , this circle is a simplification and is provided only for illustrative purposes. In this example embodiment and at the exact time corresponding to the position of vehicle  51  as shown in  FIG. 3 , only meter devices  1 ,  3 , and  4  are within range of mobile antenna  22 , and thus only data telegrams  11 ,  13 , and  14  may be received. Each of data telegrams  11 ,  13 , and  14  are stored together with the position of the vehicle  51  corresponding to the moment where the data telegrams  11 - 15  are received. In this example, the position is provided by receiving a positioning signal from at least one satellite  50  by positioning unit  52 . This could e.g. be a GPS-signal or a signal from other positioning systems such as GLONASS, Compass navigation system, Galileo positioning system, or other systems. In other embodiments, the location of the vehicle  51  may also be determined on the basis of mobile network signals or Wi-Fi signals or other radio signals, whereas in yet other embodiments, it may be obtained by manual entry of a position, such as e.g. a street address by the vehicle operator, or by other means. The identification of the meter device corresponding to the received data telegrams  11 ,  13 , and  14  may be carried out similar to the embodiment illustrated by  FIG. 2 . However, the vehicle  51  may be provided with an antenna  22  with a shorter range than a stationary antenna  20 ,  21 , as can be seen from antenna range  32  being shorter than antenna range  31  of  FIG. 2 . Therefore, the number of meter devices  1 ,  3 - 4  within the range  32  of the mobile antenna  22  is likely to be smaller than the number of meter devices  1 - 5  within the range  30  of a stationary antenna  20 . In general, a mobile antenna  22  on a vehicle  51  may cover the same area as a stationary antenna  20 , even though the mobile antenna  22  has a shorter range  32  than the range  30  of a stationary antenna  20 . Furthermore, an antenna with a short range will be able to communicate with a smaller number of meter devices, thereby reducing the need of alternative identification elements. 
         [0134]    In these examples, one aspect is to identify possible transmitting meter devices by using the location of the receiving antenna, being a stationary  20  or  21  or a mobile antenna  22 . A typical range of such an antenna gives, in the simplest form, a circular area  30 - 32  in which the transmitting meter device will be located, as it is illustrated in  FIGS. 2 and 3 . However, many other factors may be taken into consideration to determine an area in which the transmitting meter device is located and thereby identifying possible transmitting meter devices. Such factors may be one or more of e.g. height difference of ground level, buildings, reflections, weather, signal strength and type and location of meter device and meter device antenna  10 . Also, historical data about all above mentioned parameters and other factors may be taken into consideration. 
         [0135]    In the above listed example embodiments of the invention, a meter device communicates with a communication network by radio frequency wireless communication. However, in other embodiments, such communication may be by a wired communication network, by other forms of wireless transmission, or even by communication through the electricity grid. 
         [0136]    In the above example embodiments, a reduced part of an identification number, a location of the receiving antenna, and a checksum are used to identify the transmitting meter device. However, in some embodiments of the invention, only some of these elements are used, e.g. a part of an identification number and a checksum, or a part of an identification number and a location, or a location and a checksum. Also, in some embodiments other elements may be taken into consideration. Such elements could e.g. be one or more of a synchronization word, a radio channel, a reduced part of a timing information or other information elements. 
         [0137]    In one example embodiment of the invention, a part of the identification of the sender meter device  1  of a received data telegram  11  may be comprise comparing information about a synchronization word  86 . Such a synchronization word  86  is usually incorporated in the beginning of a data telegram  11 . The purpose of the synchronization word  86  is to synchronize communication between the sending meter device  1  and the communication network  75 . When the meter device  1  is sending the data telegram  11 , a carrier signal may in an embodiment be modulated by the communication signal. The communication network may, however, not know the exact timing of the communication signal, i.e. it may not know when a bit or a byte starts. Therefore, a sequence of bits called the synchronization word  86 , which does not carry any information, is sent so that the communication network  75  may adjust to the signal. More specifically, the synchronization word  86  enables the communication network  75  to work out the temporal location of the starting point of a bit and the starting point of a byte. In one embodiment of the invention, not all meter devices have the same synchronization word. According to this embodiment of the invention, the database  75  comprises information about which meter devices that uses which synchronization words  86 . When a data telegram  11  is received, at least part of the synchronization word  86  may be compared with synchronization words  86  for possible meter device identification numbers. This will limit the number of possible identification numbers. 
         [0138]    In one embodiment of the invention, information about the radio channel used to transmit the data telegram  11  may be used in identifying the sender meter device  1 . In an embodiment, not all meter devices are sending at the same frequency or radio channel. Information about the frequency or radio channel used by each of the meter devices may in this embodiment be stored in the database  75 . When the data telegram  11  is received by the communication network  75 , the frequency or radio channel by which it was sent may then be compared with database information comprising possible identification numbers and information about frequency or radio channels corresponding to each identification number. Since the meter devices in this embodiment of the invention may use different frequencies or radio channels, comparing the frequency or radio channel used for transmission with database information reduces the numbers of possible identification numbers. 
         [0139]    In one example embodiment, timing information is taken into consideration when identifying the sender meter device of a data telegram. Such timing information may come from data in the data telegram or from information obtained during the transmission of data from the meter device  1  to the communication network  75 . A meter device  1  may have an internal clock or timing function, which typically is started after or during production of the meter device. The database  70  may in an embodiment comprise information about the starting points of each of the internal clock of the meter devices. The data telegram  11  of a meter device  1  may in an embodiment comprise a time stamp or a reduced part of a time stamp, where the time stamp corresponding to the internal clock of the meter device. By comparing the time stamp or the reduced part of the time stamp received in the data telegram  11 , with the timing information in the database  70 , the number of possible identification numbers may be reduced. 
         [0140]    In another example embodiment, the timing information may relate to the temporal length of the data telegrams or information about how often these data telegrams are transmitted from the meter device. Such a sending frequency may e.g. be one data telegram every 1, 5, 15, 30, or 60 seconds or every 2, 5, 10, or 30 minutes, or even at other time intervals such as hours, days, or months. In an embodiment where the data telegrams are received by a mobile antenna  22 , it is important that the sending frequency is high enough for the vehicle to receive the data telegram during bypass. 
         [0141]    When a meter device  1  is installed, there will according to an embodiment of the invention, be a need to follow certain procedures. This could e.g. be that the meter device  1  is linked to a certain antenna or that other data about the meter device  1  is determined and transferred to the relevant database  70 . In one embodiment the meter device  1  comprises a function to send a full data telegram  60  during installation, e.g. by pressing a button on the meter device  1 . Hereby, the full identification number  74 , full time data and other relevant information, such as information about synchronization word, radio channel etc., is received by an antenna and stored in the database  70 . If the database  70  or part of it is lost or damaged, it may have to be reconstructed in order to provide identification elements for the identification. This may be done in various ways. In an example embodiment, this can be done by reinstallation as described above, i.e. by manually visiting the meter devices and acquiring the lost information, e.g. identification number, location, timing information, synchronization word, radio channel, etc. In another example embodiment of the invention, the meter devices may be able to receive a request from the communication network  75  and as a result send a data telegram containing enough information to perform a complete identification and/or reconstruction of the database information. Such information may be e.g. a complete identification number, synchronization word, radio channel, complete timing information, etc. Another way of reconstructing the database  70  is by requesting a list of identification numbers from the manufacturer(s) of the meter devices. Such a list of identification numbers may preferably contain further identification information, such as timing information or starting point of the internal clock, synchronization words, radio channels, etc. 
         [0142]    It may in one embodiment be necessary to perform two-way communication between the meter device  1  and the communication network  75  if the synchronization between the internal clock of the meter device  1  and the clock used in the identification computer means  73  is lost. 
         [0143]    Referring to  FIG. 7 , an example embodiment of the invention is shown. An example of a meter device  1  is shown. The meter device  1  comprises a meter device antenna  10 , a meter device processor  80 , a meter device storage  81 , and meter device measuring means  82  for measuring a physical quantity, such as e.g. water, gas, heat, electricity, etc. Finally, the meter device  1  comprises a meter device identification  83 , which comprises a reduced part of the meter device identification  84 , and an internal timing function  87 . The meter device antenna  10  may transmit a data telegram  11  according to information such as a reduced part of the meter device identification  84  or timing data stored in meter device storage  81  and according to information from the meter device measuring means  82 . 
         [0144]    Referring to  FIG. 8 , a data telegram  60  according to an embodiment of the invention is illustrated. According to the embodiment, the data telegram  60  comprises a synchronization word  86  for synchronizing communication between a meter device  1  and a communication network  75 , a reduced part of a meter device identification  84 , a data field  62 , timing data  85 , and a checksum  63 . The timing data  85  relates to the internal timing function  87  of the meter device  1 . In one embodiment of the invention, the internal timing function  87  counts the time from the fabrication of the meter device  1 . The timing data  85  may then be e.g. a reduced part of a time stamp at the moment where the data telegram  60  is transmitted, such as the last bit of the time stamp. It may, however, also be a full time stamp or other timing data  85  relating to the internal timing function  87 . 
       REFERENCE NUMERALS 
       [0000]    
       
           1 . Meter device  1   
           2 . Meter device  2   
           3 . Meter device  3   
           4 . Meter device  4   
           5 . Meter device  5   
           6 . Meter device  6   
           7 . Meter device  7   
           10 . Meter device antenna 
           11 . Data telegram from meter device  1   
           12 . Data telegram from meter device  2   
           13 . Data telegram from meter device  3   
           14 . Data telegram from meter device  4   
           15 . Data telegram from meter device  5   
           16 . Data telegram from meter device  6   
           17 . Data telegram from meter device  7   
           20 . Stationary antenna 
           21 . Stationary antenna 
           22 . Mobile antenna 
           30 . Range of antenna  20   
           31 . Range of antenna  21   
           32 . Range of antenna  22   
           51 . Vehicle 
           52 . Positioning unit 
           54 . All identification numbers of the database 
           55 . Identification numbers matching location information 
           56 . Identification numbers matching part of ID number 
           57 . Identification numbers matching a checksum 
           58 . Identification number matching all criteria 
           60 . Data telegram 
           61 . Reduced part of identification number 
           62 . Data field 
           63 . Checksum 
           70 . Database 
           71 . List of identification elements 
           72 . Request for identification numbers 
           73 . Identification computer means 
           74 . Full identification number 
           75 . Communication network 
           80 . Meter device processor 
           81 . Meter device storage 
           82 . Meter device measuring means 
           83 . Meter device identification 
           84 . Reduced part of meter device identification 
           85 . Timing data 
           86 . Synchronization word 
           87 . Internal timing function 
           101 . First checksum 
           102 . Second checksum 
           103 . Length of data telegram 
           104 . Header 
           105 . Redundant information 
           106 . Complete data field 
           107 . Data information field 
           108 . Complete set of information 
           109 . Reduced set of information 
           110 . Part of timing data 
           111 . Full data telegram 
           112 . Reduced data telegram