JP5340082B2 - Signal relay apparatus and signal relay method - Google Patents

Description

  The present invention relates to a signal relay apparatus and a signal relay method for relaying a control signal transmitted and received between a base station and a core network in an access line of a portable radio communication system.

  In a conventional portable radio communication system (hereinafter referred to as a radio communication system), when a mobile station changes a connection-destination radio base station (hereinafter referred to as a base station), the position corresponding to the base station after the change It is confirmed whether or not the registration area has changed from the location registration area corresponding to the base station of the connection destination so far, and if it has changed, location registration is performed. Further, when a core network (core network) calls a mobile device, the mobile device transmits a call signal to all base stations existing in the location registration area where the location registration has been performed. Here, if the location registration area is set for each base station, the call signal is transmitted to only one base station, and the call signal can be reduced. However, in this case, since the location registration area is a base station unit, the location registration signal from the mobile device increases.

  In wireless communication systems, it is one of the issues to realize effective use of wireless resources, and it is important to minimize the amount of control signals transmitted and received in the system. Therefore, the location registration area is designed so that the sum of traffic (total traffic amount) of the control signal related to the location registration operation and the control signal related to the call operation is minimized. All base stations in the location registration area).

  Note that the call signal may be transmitted to the mobile device in communication. However, if the mobile device is in communication, a signal connection already exists with the core network. If the call signal is transmitted to the mobile phone, the call signal is transferred only to a specific base station. That is, by performing such control, it is possible to reduce the call signal for the mobile device in communication.

  Examples of techniques that can reduce control signals are described in Patent Documents 1 and 2 below. Specifically, in Patent Document 1 below, the radio network control device does not transmit a paging message (corresponding to the above-described call signal) to all connected base stations, but between the mobile communication terminals. Describes a control method for transmitting a paging message only to a base station for which a signal connection is established. Patent Document 2 below describes a control method for reducing the number of times of transmission / reception of control signals by combining a call message (corresponding to the call signal described above) with a message of a higher protocol.

Special Table 2002-527965 gazette JP 2002-58053 A

  However, there is a problem that a call signal for a mobile device having no signal connection (a mobile device that is not communicating) is transmitted to all base stations in the location registration area in any of the control methods described above. . That is, the conventional control method has a problem that the reduction of the call signal transmitted in the system is insufficient.

  In a conventional wireless communication system, a form configured to perform wired communication over the entire access line between the base station and the core network was common, but in recent years, using a wireless relay network, A system configuration for performing wireless communication through an access line has also been studied. In such a connection form using a wireless relay network, there is a signal connection, not a method that can reduce the traffic of the call signal when a signal connection exists between the mobile station and the core network as described above. Even if not, it is desirable to apply a technique that can reduce the traffic of the call signal.

  The present invention has been made in view of the above, and provides a signal relay apparatus and a signal relay method for realizing a wireless communication system that reduces traffic of a call signal and suppresses a signal amount required for a control operation to be lower than conventional ones. The purpose is to obtain.

  In order to solve the above-described problems and achieve the object, the present invention provides that an access line connecting a plurality of base stations and a core network includes a radio relay network, and the radio relay network includes the core network and the plurality of core networks. In a portable radio communication system including a plurality of relay radio channels for transmitting signals transmitted to and received from any one of base stations, a control signal is relayed between the core network and the radio relay network When a location registration is performed, the mobile radio device that has performed location registration and the relay radio circuit used when the mobile device communicates based on the control signal for the location registration When the table is updated and a call signal is received, the relay radio line to which the call signal is transferred is determined based on the correspondence table.

  According to the present invention, since the call signal is transmitted only to the mobile base station that accommodates the mobile device indicated by the call signal, unnecessary call signals in the radio communication system can be reduced, and the control operation can be performed. There is an effect that the amount of the signal can be suppressed to be lower than the conventional amount.

FIG. 1 is a diagram showing a configuration example of a portable radio communication system using a signal relay device according to the present invention. FIG. 2 is a diagram illustrating a configuration example of the signal relay device according to the present invention.

  Embodiments of a signal relay device and a signal relay method according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a diagram showing a configuration example of a portable radio communication system (hereinafter referred to as a radio communication system) using a signal relay device according to the present invention. This wireless communication system includes a mobile core network 1, a connection device 2, a relay wireless core network 3, a plurality of relay wireless master stations 4, a plurality of relay wireless slave stations 5, a plurality of mobile base stations 6, and a plurality of mobile mobile devices ( (Hereinafter referred to as a mobile device) 7. The relay radio master station 4 and the relay radio slave station 5 communicate via a relay radio line. The mobile base station 6 and the mobile device 7 communicate via a mobile wireless line.

  In the wireless communication system having the above-described configuration, the mobile core network 1 manages the location of the mobile device 7. The relay radio network is used as an access line for the mobile radio network and is located between the mobile base station 6 and the mobile core network 1. That is, the relay radio network includes the relay radio slave station 5, the relay radio master station 4, the relay radio core network 3, and the connection device 2, and the mobile core network 1 and the relay radio core network 3 are the signal relay device according to the present invention. Are connected by a connection device 2 corresponding to A signal directed from the mobile core network 1 to the mobile device 7 is sent to the relay radio core network 3 via the connection device 2 and further transmitted to the relay radio master station 4 via a wired line. The data is transmitted to the slave station 5 via a relay radio line. The relay radio slave station 5 and the mobile base station 6 are connected by wire, and a signal from the mobile core network 1 received via the relay radio channel is sent from the relay radio slave station 5 to the mobile base station 6, and the mobile radio channel Is transmitted to the mobile device 7. On the contrary, a signal from the mobile device 7 to the mobile core network 1 is transmitted to the mobile base station 6 via the mobile radio line, and sent from the mobile base station 6 to the relay radio slave station 5. Further, it is transmitted from the relay radio slave station 5 to the relay radio master station 4 via the relay radio line and sent to the mobile core network 1 via the relay radio core network 3 and the connection device 2.

  Here, only the control signal between the mobile device 7 and the mobile core network 1 and the control signal between the mobile base station 5 and the mobile core network 1 are transmitted / received via the connection device 2, and the mobile device 7 and the mobile core network 1 are transmitted / received. 1 may be directly transmitted / received between the relay wireless core network 3 and the mobile core network 1 without going through the connection device 2. 1 shows an example in which the mobile device 7 and the mobile base station 5 are connected one-to-one, but the mobile base station 5 may have a configuration in which a plurality of mobile devices 7 are accommodated. Similarly, the relay radio slave station 5 may be configured to accommodate a plurality of mobile base stations 5. Further, the relay radio master station 4 may also be configured to accommodate a plurality of relay radio slave stations 5. However, the control signal transmission connection between the mobile device 7 and the mobile core network 1 must be a logically or physically independent connection between the connection device 2 and the mobile device 7. Similarly, the connection for control signal transmission between the mobile base station 5 and the mobile core network 1 must be a logically or physically independent connection.

  FIG. 2 is a diagram illustrating a configuration example (functional block configuration example) of the connection device 2. As illustrated, the connection device 2 includes a message transmission / reception unit 20, a message extraction unit 21, a message transfer unit 22, a relay line selection unit 23, a message analysis unit 24, a relay line number extraction unit 25, a message generation unit 26, a correspondence table. An updating unit 27 and a correspondence table reading unit 28 are provided, and a correspondence table 29 is held. The relay line number extraction unit 25 and the correspondence table update unit 27 constitute an updating unit, and the relay line selection unit 23, the message generation unit 26, and the correspondence table reading unit 28 constitute a relay radio channel determination unit.

  In the connection device 2, the message transmission / reception unit 20 transmits / receives a control signal from the mobile core network 1 to the mobile device 7 or the mobile base station 6 and a control signal from the mobile device 7 or the mobile base station 6 to the mobile core network 2. The message extraction unit 21 extracts a specific control message from the control signal received by the message transmission / reception unit 20. The message transfer unit 22 outputs a message to be transmitted to the mobile core network 1 or a message to be transmitted to the mobile device 7 or the mobile base station 6 via the relay radio core network 3 to the message transmitting / receiving unit 20. The relay line selection unit 23 determines a relay radio line to be used when the message transmission / reception unit 20 transmits a message to the relay radio core network 3. The message analysis unit 24 analyzes the control message extracted by the message extraction unit 21. The relay line number extraction unit 25 extracts information on the relay radio line number included in the information received from the message analysis unit 24. The message generation unit 26 generates a control message to be transmitted by the message transmission / reception unit 20 based on the analysis result of the message analysis unit 24 and the read result output from the correspondence table reading unit 28. The correspondence table update unit 27 updates the correspondence table 29 based on the relay radio line number information extracted by the relay line number extraction unit 25. The correspondence table reading unit 28 reads the correspondence table 29 in response to an instruction from the message generation unit 26. The correspondence table 29 is a table showing a correspondence relationship between the relay radio line number and the mobile device 7.

  The detailed operation of the connection device 2 will be described. When the user data is transmitted via the connection device 2, the connection device 2 performs a general transfer operation (simple relay operation) when receiving the user data. Therefore, here, a transmission / reception operation of a control signal (control message), which is a characteristic operation performed by the connection apparatus 2 will be described.

  When the message transmission / reception unit 20 receives a control message from the mobile core network 1 or the relay radio core network 3, the message transmission / reception unit 20 assigns a number for identifying the control message (hereinafter referred to as a message identification number) and then extracts the message. And a pair of the assigned message identification number and the number of the relay radio line to which the received control message is transmitted is passed to the relay line number extraction unit 25. The message extraction unit 21 that has received the control message from the message transmission / reception unit 20 is a location registration message (a signal for requesting location registration) transmitted from the mobile device 7 to the mobile core network 1. If the message is a location registration response message (response signal to the location registration message) transmitted to 7 or a call message (signal for calling the mobile device 7) received from the mobile core network 1, the message is delivered to the message analysis unit 24. Further, signals other than these are delivered from the message extraction unit 21 to the message transfer unit 22, and after the message transfer unit 22 specifies the transmission destination, the mobile core network 1 or the relay radio core is transmitted via the message transmission / reception unit 20. It is transmitted to the network 3.

  The message analysis unit 24 analyzes the control message received from the message extraction unit 21. If the control message is a location registration message, the identifier of the mobile device 7 (hereinafter referred to as a mobile device identifier) stored in the message. ) And the message identification number assigned to the location registration message (message identification number assigned by the message transmitting / receiving unit 20). The extracted mobile unit identifier and message identification number are paired and passed to the trunk line number extraction unit 25. When the relay line number extraction unit 25 receives the pair of the mobile unit identifier and the message identification number from the message analysis unit 24, the relay line number extraction unit 25 and the information (the pair of the message identifier and the relay radio line number) received in advance from the message transmission / reception unit 20 Based on the above, the relay radio channel number corresponding to the mobile station identifier received from the message analysis unit 24 is determined, and the set of the message identification number, the mobile station identifier and the relay radio channel number is transferred to the correspondence table update unit 27. The correspondence table update unit 27 stores information (a set of a message identification number, a mobile unit identifier, and a relay wireless line number) received from the relay line number extraction unit 25.

  In addition, if the control message received from the message extraction unit 21 is a location registration response message, the message analysis unit 24 analyzes the message, which is a normal response signal (a location registration response including information indicating a normal response). Message), the message identification number (location registration message identification number) stored when the location registration message corresponding to this location registration response message is processed and the information indicating the normal response are relay line numbers. Delivered to the extraction unit 25. When the trunk line number extraction unit 25 receives a message identification number and information indicating a normal response (information indicating that a normal location registration message has been received) from the message analysis unit 24, the message identification number (location registration message (Identification number) is notified to the correspondence table update unit 27 and an instruction to update the correspondence table 29 is given. When the correspondence table update unit 27 receives the notification of the message identification number and the instruction to update the correspondence table from the relay line number extraction unit 25, the mobile unit identifier and the relay radio line number (notified message identification) corresponding to this message identification number The correspondence table 29 is updated based on the mobile device identifier and the relay radio line number stored in association with the same message identification number as the number. That is, the mobile unit identifier and the relay radio line number are registered in the correspondence table 29. When the same mobile station identifier as that to be registered has already been registered, the registered mobile station identifier and the relay radio line number associated therewith are overwritten and registered.

  On the other hand, if the control message received from the message extraction unit 21 is a location registration response message and is not a normal response signal, the message analysis unit 24 stores the location registration message corresponding to the location registration response message when it is processed. The message identification number and the information indicating that the response is not normal are delivered to the trunk line number extraction unit 25. When the trunk line number extraction unit 25 receives the message identification number and information indicating that it is not a normal response from the message analysis unit 24, the relay line number extraction unit 25 notifies the correspondence table update unit 27 of the message identification number and the correspondence table 29. Instruct to maintain. When the correspondence table update unit 27 receives the notification of the message identification number and the instruction to maintain the correspondence table from the relay line number extraction unit 25, the correspondence table update unit 27 discards the mobile unit identifier and the relay radio line number corresponding to the message identification number.

  In addition, if the control message received from the message extraction unit 21 is a call message, the message analysis unit 24 extracts the mobile device identifier included therein and delivers it to the message generation unit 26. A single call message may include a plurality of mobile station identifiers. In this case, all included mobile station identifiers are delivered to the message generator 26. The message generation unit 26 instructs the correspondence table reading unit 28 to read the relay radio line number using the mobile device identifier received from the message analysis unit 24 as a search key. Upon receiving this instruction, the correspondence table reading unit 28 confirms the correspondence table 29, reads the relay radio line number corresponding to the mobile device identifier, and delivers it to the message generation unit 26. When a plurality of mobile station identifiers are included in the call message, the relay radio line numbers corresponding to the respective mobile station identifiers are read out and delivered to the message generator 26. If the corresponding relay radio line number is not registered in the correspondence table 29, the message generation unit 26 is notified of this fact. When there are a plurality of mobile station identifiers with the same relay radio channel number, the message generator 26 that has received the relay radio channel number from the correspondence table reading unit 28 generates a call message including all of the mobile station identifiers (two This may be the case). In the case of different relay radio channel numbers, a call message is generated for each relay radio channel number. However, when receiving a notification from the correspondence table reading unit 28 that there is no corresponding relay radio channel number, the message generation unit 26 does not generate a call message corresponding to the mobile device identifier received from the message analysis unit 24.

  When the message generation unit 26 generates a call message, the message generation unit 26 delivers the generated call message and the corresponding relay radio line number to the relay line selection unit 23 as a pair. The relay line selection unit 23 assigns a message identification number to the received call response message, notifies the message transmission / reception unit 20 of the pair of the relay radio line number and the message identification number, and also transmits to the message transfer unit 22. The call message with the message identification number is delivered. When the message transmission / reception unit 20 receives a call message with a message identification number from the message transfer unit 22, the message transmission / reception unit 20 relays the relay radio channel number (message identification number and relay radio channel number) previously notified from the relay channel selection unit 23. The relay radio channel of the relay radio channel number corresponding to the message identification number given to the received call message is selected from the pair of), and the received call message is selected using this relay radio channel. Send.

  Here, in the above operation, when there are a plurality of mobile device identifiers in the call message received from the mobile core network 1, the message generator 26 collects the mobile device identifiers in units of relay radio channel numbers and sends the call message. Although the message analysis unit 24 analyzes the message received from the message extraction unit 21 and determines that the call message has been received, the message analysis unit 24 assigns a message identification number to the call message and sends the message transfer unit 22. The message generator 26 extracts the relay radio line number in the same manner as described above, but does not newly generate a call message, and stores it in the message transfer unit 22 for each relay radio line number as the transmission destination. The call message received from the mobile core network 1 is transmitted as it is. It may be.

  As described above, in the wireless communication system according to the present embodiment, the connection device that relays the control signal transmitted and received between the mobile core network and the relay wireless core network includes the control message related to location registration among the received control signals. Based on (location registration message, location registration response message), the information (relay radio channel number) of the relay radio channel corresponding to the location of each mobile device in the system (mobile base station accommodating each mobile device) and Create (update) the correspondence table with the mobile device identifier, and when the connection device receives the call message from the mobile core network, the correspondence that has created the relay radio line corresponding to the mobile device identifier included therein The call message is transferred to the specified relay radio line using the table. As a result, since the call message is transmitted only to the mobile base station that accommodates the mobile station indicated by the call message, unnecessary call messages in the radio communication system can be reduced, and the bandwidth of the relay radio line can be reduced. Can be used effectively.

Embodiment 2. FIG.
Next, the second embodiment will be described. The configurations of the wireless communication system and the connection device are the same as those in the first embodiment (see FIGS. 1 and 2).

  In the first embodiment, the mobile device identifier and the relay radio channel number are stored in the correspondence table 29 in a one-to-one correspondence. However, a part of the mobile device identifier, for example, the least significant 2 bytes of the mobile device identifier is stored. The correspondence table 29 may be stored in association with the relay radio line number. Thereby, the search key is shortened, so that the search speed of the correspondence table 29 can be increased.

  That is, in the present embodiment, the correspondence table update unit 27 registers and updates a set of a part of the mobile device identifier as a search key and the relay radio channel number in the correspondence table 29. In the present embodiment, an example in which a part of the mobile device identifier is used has been described. However, a result obtained by performing a simple calculation using the mobile device identifier as an input may be used as a search key.

  By adopting the configuration as described above, the same effects as those of the first embodiment can be obtained, and the search processing of the relay radio channel (relay radio channel of the call message transmission destination) in the connection device 2 can be reduced. it can.

  As described above, the signal relay device and the signal relay method according to the present invention are useful for a mobile radio communication system, and in particular, between a radio line and a core network in a mobile radio communication system to which a radio line is applied as an access line. It is suitable for communication devices that relay control signals.

DESCRIPTION OF SYMBOLS 1 Mobile core network 2 Connection apparatus 3 Relay radio | wireless core network 4 Relay radio | wireless master station 5 Relay radio | wireless slave station 6 Mobile base station 7 Portable mobile device 20 Message transmission / reception part 21 Message extraction part 22 Message transfer part 23 Relay line selection part 24 Message analysis Section 25 Relay line number extraction section 26 Message generation section 27 Correspondence table update section 28 Correspondence table reading section 29 Correspondence table

Claims (9)

An access line connecting a plurality of base stations and a core network includes a radio relay network, and the radio relay network transmits signals transmitted and received between the core network and any one of the plurality of base stations. In a portable radio communication system including a plurality of relay radio channels for performing, a signal relay device that relays a mobile station call signal received from the core network to any one of the relay radio channels ,
When location registration is executed, based on the control signal for the location registration, the correspondence table of the relay radio circuit used when the mobile device that has performed location communication and the mobile device communicates is updated and called. In the case of relaying a signal, a signal relay apparatus characterized in that a relay radio channel to which a call signal is transmitted is determined based on the correspondence table. A message extraction means for extracting a location registration message and a location registration response message, which are control signals for the location registration, and a call message, which is the call signal, from a received signal;
Message analysis means for analyzing each message extracted by the message extraction means;
When the location analysis message and the location registration response message are analyzed by the message analysis unit, an update unit that updates the correspondence table based on each analysis result;
When a call message is analyzed by the message analysis unit, based on the analysis result and the correspondence table, a relay radio channel determination unit that determines a relay radio channel as a transmission destination of the call message;
The signal relay device according to claim 1, further comprising: The updating means includes
When the location registration message is analyzed by the message analysis unit, the mobile device identifier obtained by the analysis process or a part of the mobile device identifier is acquired and stored as mobile device identification information, If the location registration response message is analyzed by the message analysis means and it is determined that the location registration response message is a normal response signal, the correspondence table is updated based on the stored mobile device identification information. The signal relay device according to claim 2. The updating means includes
When acquiring and holding the mobile station identification information, the mobile station identification information is stored in association with a relay radio channel number that is identification information of the relay radio channel from which the location registration message has been transmitted, and the correspondence table update process Then, the stored mobile station identification information and relay radio channel number are registered in the correspondence table. 4. The signal relay apparatus according to claim 3, wherein: The updating means includes
When the location analysis response message is analyzed by the message analysis means and it is determined that the location registration response message is not a normal response signal, the stored information is discarded, and the correspondence table is not updated. 5. The signal relay device according to claim 3 or 4, The relay radio line determining means further includes:
Based on the analysis result of the call message in the message analysis means, a new call message having the same content as the call message is generated,
6. The signal relay apparatus according to claim 2, wherein the new call message is transmitted to the determined relay radio line. When the analysis result of the call message includes a plurality of mobile station identifiers,
The relay radio line determining means is
Based on the plurality of mobile station identifiers or a part of each mobile station identifier, a relay radio channel to which a call message is transmitted is determined, and the number of new call messages is the same as the determined number of relay radio channels. Each of the new call messages is generated based on the analysis result of the call message and the correspondence table, a message including a mobile station identifier associated with the relay radio channel of the transmission destination,
7. The signal relay apparatus according to claim 6, wherein each of the new call messages is transmitted to a corresponding relay radio line. An access line connecting a plurality of base stations and a core network includes a radio relay network, and the radio relay network transmits signals transmitted and received between the core network and any one of the plurality of base stations. In a portable radio communication system including a plurality of relay radio channels for performing, a signal relay method executed by a connection device arranged between the core network and the radio relay network,
When receiving a location registration message, the location registration message is analyzed, and a mobile device identifier or a part of the mobile device identifier included in the location registration message is acquired as mobile device identification information. An information acquisition step;
When the location registration response message is received and it is a normal response signal, the mobile device that has performed location registration and the mobile device based on the mobile device identification information acquired in the mobile device identification information acquisition step A correspondence table update step for updating the correspondence table of the relay radio circuit used for communication;
A call signal transfer step of determining a relay radio line as a transmission destination of the call signal based on the correspondence table and transferring the received call signal to the determined relay radio line when the call signal is received;
The signal relay method characterized by including. In the mobile device identification information acquisition step,
Storing the acquired mobile device identification information in association with the relay radio channel number that is the identification information of the relay radio channel from which the location registration message has been transmitted,
In the correspondence table update step,
9. The correspondence table is updated by registering the mobile device identification information and the relay radio channel number stored in the mobile device identification information acquisition step in the correspondence table. Signal relay method.

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