JP2013102361A - Mobile communication system, backhaul route configuration method and center monitoring device - Google Patents

Abstract

Communication service is prevented from being interrupted when a backhaul line of a radio base station fails and communication becomes impossible.
When a failure occurs in a backhaul line 50 of a radio base station 20A, transmission power of the radio base station 20A and a radio base station 20B in the vicinity thereof is increased to a predetermined value larger than normal. Accordingly, the cover areas 40A and 40B are enlarged, and communication can be performed between the radio base station 20A and the radio base station 20B. Then, a relay path is performed between the radio base station 20A and the radio base station 20B, and a detour path through which information transmitted / received between the radio base station 20A and the mobile terminal 30A is transmitted via the radio base station 20B. Is built.
[Selection] Figure 3

Description

  The present invention relates to a technique for preventing a communication service from being interrupted even when a failure occurs in a backhaul line of a radio base station used for mobile communication.

  A mobile communication system places a radio base station in an area that provides a communication service, and transmits / receives information to / from mobile terminals that exist in the coverage area of the radio base station. In addition, the radio base station is connected to the backbone network via a backhaul line, and transmits information to and from other radio base stations via the backbone network, and various servers and users connected to the backbone network. Send and receive information to and from terminals.

  In a mobile communication system in an urban area, a plurality of radio base stations are densely stationed to cover the number of user-connected calls and communication traffic after call connection, and a plurality of coverage areas are overlapped. ing. Therefore, when a backhaul line cannot be communicated in a certain radio base station A, a call of a mobile terminal within the coverage area of that radio base station A is another overlapped cover area. The wireless base station B is switched to continue transmission. In other words, by providing the wireless base station as a redundant configuration, the communication service is prevented from being interrupted by a backhaul line failure (see, for example, Patent Document 1).

JP 2009-206764 A

  However, in areas where fields and forests spread, wireless base stations are scattered along the main road, and there is little overlap between the cover areas, so there is no redundant configuration of wireless base stations. There is a case. Further, in such an area, if the wireless base station is permanently configured in a redundant configuration, there is a problem that the cost increases.

  Therefore, an object of the present invention is to prevent communication service from being interrupted when a failure occurs in a backhaul line of a radio base station and communication becomes impossible.

  In order to solve the above-mentioned problems, the present inventors have conducted intensive research and do not construct a redundant configuration, but take emergency measures to prevent the communication service from being interrupted only for a short period until the backhaul line is restored. The present invention was completed by paying attention to the fact that it would be more cost-effective to take it. That is, the mobile communication system according to the present invention detects a radio base station (hereinafter referred to as a faulty radio base station) in which a fault has occurred in the backhaul line, and detects a faulty radio base station and a faulty radio base station nearby. Increase the transmission power of the radio base station, send and receive information (relay communication) between the faulty radio base station and the neighboring radio base station, and via the neighboring radio base station (via the detour path) ) Continue to send and receive information so that the communication service is not interrupted.

  According to the present invention, it is possible to prevent the communication service from being interrupted when a failure occurs in the backhaul line of the radio base station and communication becomes impossible.

It is a figure which shows the structural example of the mobile communication system at the normal time in this embodiment. It is a figure which shows the example of a channel use in the time division multiplex communication system in normal time. It is a figure which shows an example when a failure generate | occur | produces in a backhaul line and a detour route is constructed | assembled. It is a figure which shows the example of a channel use in case a detour route is constructed | assembled. It is a figure which shows the structural example of a center monitoring apparatus. It is a figure which shows the structural example of a wireless base station. It is a figure which shows the example of a process sequence of the mobile communication system in this embodiment. It is a figure which shows the continuation of the example of a process sequence of the mobile communication system in this embodiment. It is a figure which shows the example of a processing flow of a center monitoring apparatus. It is a figure which shows the continuation of the example of a processing flow of a center monitoring apparatus.

  Next, a mode for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail with reference to the drawings as appropriate.

FIG. 1 shows a configuration example of a mobile communication system 1 at a normal time in the present embodiment.
As shown in FIG. 1, the mobile communication system 1 is connected to a radio base station 20 (20A, 20B, 20C, 20D), a backhaul line 50 connecting the radio base station 20 and the backbone network 60, and the backbone network 60. The center monitoring apparatus 10 is configured. In FIG. 1, four wireless base stations 20 are shown, but the number is not limited to four.

  Further, FIG. 1 shows mobile terminals 30 (30A, 30B, 30D). The mobile terminal 30 is, for example, a mobile terminal or a mobile phone that is carried by a mobile body, and can transmit and receive information to and from the radio base station 20 by radio. In FIG. 1, only three mobile terminals 30 are shown, but the number is not limited to three, and a plurality of mobile terminals 30 exist in one cover area 40, and one mobile base station 20 Information shall be sent and received between them.

  The radio base station 20 has a function of wirelessly transmitting and receiving information to and from the mobile terminal 30 existing in the range of the cover area 40 (40A, 40B, 40C, 40D) determined by normal transmission power. For example, when the mobile terminal 30A in the cover area 40A transmits information destined for the mobile terminal 30D, an exchange / relay function (not shown) in the radio base station 20A, the backhaul line 50, and the backbone network 60 is performed. Information is transmitted to the mobile terminal 30D in the cover area 40D via the provided server (exchange device, relay device) and the radio base station 20D. Details of the function of the radio base station 20 will be described later.

  The center monitoring apparatus 10 is operated by a supervisor and has a function of monitoring a failure or a recovery state in the mobile communication system 1. Details of the functions of the center monitoring apparatus 10 will be described later.

FIG. 2 shows an example of channel use in a normal time division multiplex communication system performed between the radio base station 20 and the mobile terminal 30. Note that FIG. 2 shows a case of two channels in order to simplify the description of the time division multiplex communication system.
For example, the upper diagram in FIG. 2 illustrates a case where communication is performed using the channel 1 between the radio base station 20B and the mobile terminal 30B. TX1 represents a transmission channel, and RX1 represents a reception channel. In channel 2, both TX2 and RX2 are described. This indicates that channel 2 is not used.

  The diagram in the middle of FIG. 2 represents a case where channel 1 is used between the radio base station 20A and the mobile terminal 30A. The lower diagram in FIG. 2 illustrates a case where channel 2 is used between the radio base station 20D and the mobile terminal 30D. In the communication between each radio base station 20 and the mobile terminal 30, no interference occurs with other radio base stations 20 in normal times.

Next, FIG. 3 shows a case where a failure occurs in the backhaul line of the radio base station 20A and a detour path is established.
The transmission power of the radio base station 20A and the radio base station 20B in the vicinity of the radio base station 20A is increased to a predetermined value, and the cover areas 40A and 40B are expanded from the case of FIG. Therefore, communication can be performed between the radio base station 20A and the radio base station 20B. Then, relay communication is performed between the radio base station 20A and the radio base station 20B, and a detour path for transmitting information transmitted / received by the radio base station 20A via the radio base station 20B is established. In the following description, the radio base station 20 that relays information, such as the radio base station 20B, is referred to as a donor station.

  FIG. 4 shows an example of channel use when a detour route is constructed. As shown in the upper diagram and the middle diagram in FIG. 4, the radio base station 20 </ b> B and the radio base station 20 </ b> A perform relay communication using the channel 2. At this time, as shown in the lower diagram of FIG. 4, since the radio base station 20D and the mobile terminal 30D use the channel 2, the transmission wave from the radio base station 20D becomes an interference wave, The radio wave is received by the station 20A, and the transmission wave from the radio base station 20A becomes an interference wave and is received by the radio base station 20D. Therefore, an instruction is issued from the center monitoring apparatus 10 so that the channel 2 cannot be used in the radio base station 20D at a position where the transmission wave becomes an interference wave. Details of the channel unusable will be described later.

  In FIG. 4, since the number of channels in the time division multiplex communication system has been described as being two, at first glance, it seems that communication between the mobile terminal 30D using the channel 2 and the radio base station 20D is disconnected. The communication between the mobile terminal 30D and the radio base station 20D can be continued by changing the channel 1 to an empty channel. In the time division multiplex communication system that is actually used, since the number of channels is larger than 2 and there are vacant channels, it is easy to continue communication by switching channels.

Next, a configuration example of the center monitoring apparatus 10 will be described with reference to FIG. 5 (see FIG. 1 as appropriate).
The center monitoring apparatus 10 includes a processing unit 11 that executes various processes using a CPU (Central Processing Unit) and a main memory (not shown), a storage unit 12 that stores application programs and the like, an input / output unit 13 and a communication unit 14. .

  The processing unit 11 develops the application program stored in the storage unit 12 in the main memory and realizes the failure detection unit 111, the candidate radio base station selection unit 112, and the candidate radio base station control unit 113 as functions. .

  The failure detection unit 111 transmits arrival confirmation information to the radio base station 20 at a predetermined cycle in order to detect a failure in the backhaul line 50. The predetermined cycle may be a regular or irregular cycle. Then, the failure detection unit 111 determines that there is a failure in the backhaul line 50 when no response information for the arrival confirmation information is received from the radio base station 20, and detects the failure. Moreover, the failure detection unit 111 determines that there is no failure in the backhaul line 50 when receiving response information for the arrival confirmation information. However, the failure detection unit 111 determines that the backhaul line 50 has been restored if it has detected a failure until immediately before determining that there is no failure, and detects the recovery.

  The candidate radio base station selection unit 112 determines the position of the radio base station 20 (that is, the faulty radio base station) where the backhaul line 50 has failed in order to determine the donor station (the radio base station 20 that relays information). And the radio base station 20 existing within a predetermined distance from the faulty radio base station is a candidate radio base station 20 for relay communication (hereinafter referred to as a candidate radio base station). Choose as. Specifically, the candidate radio base station selection unit 112 reads the position (latitude, longitude) of the radio base station 20 with reference to the radio base station position information 121 stored in the storage unit 12, A radio base station 20 within a predetermined distance from the station is selected as a candidate radio base station.

  The candidate radio base station control unit 113 instructs the candidate radio base station 20 to increase the transmission power to a predetermined value larger than the normal value or return it to the normal value, an instruction to try to connect to the failed radio base station, Control by sending an instruction to disable the channel for relay communication. Details of the control will be described later.

The storage unit 12 stores radio base station position information 121, an application program (not shown), and the like.
The radio base station position information 121 stores latitude and longitude as position information for each base station ID that identifies the radio base station 20. In addition, it is preferable that the wireless base station position information 121 stores not only latitude and longitude but also altitude so that the distance can be calculated more accurately.

  The input / output unit 13 has functions of an input interface for connecting an input device such as a keyboard and a mouse and an output interface for connecting a display device such as a display. The input / output unit 13 receives information input from an input device operated by a supervisor, Information such as a message prompting input is output to the display device.

  The communication unit 14 has a communication interface function for transmitting and receiving information via the backbone network 60.

Next, a configuration example of the radio base station 20 will be described with reference to FIG. 6 (see FIG. 1 as appropriate).
As shown in FIG. 6, the radio base station 20 includes a CPU (Central Processing Unit) and a main memory (not shown) that execute various processes, a storage unit 22 that stores application programs, an input / output unit 23, and the like. A communication unit 24 is provided.

  The processing unit 21 develops the application program stored in the storage unit 22 in the main memory, and realizes the failure detection unit 211, the transmission power control unit 212, the channel control unit 213, and the communication processing unit 214 as functions. .

  If the failure detection unit 211 detects that the arrival confirmation information that should be received from the center monitoring apparatus 10 in a predetermined cycle is not received, the failure detection unit 211 determines that there is a failure in the backhaul line 50 and detects the failure. Further, when the arrival detection information is received, the failure detection unit 211 determines that there is no failure in the backhaul line 50 and returns response information to the center monitoring apparatus 10. However, the failure detection unit 211 determines that the backhaul line 50 has been recovered and detects the recovery when it has detected a failure until immediately before determining that there is no failure.

  The transmission power control unit 212 increases the transmission power to a predetermined value larger than the normal value or returns it to the normal value based on an instruction from the center monitoring apparatus 10.

  Based on an instruction from the center monitoring apparatus 10, the channel control unit 213 disables the channel used for relay communication or cancels the unusable channel.

  The communication processing unit 214 transmits / receives information to / from the mobile terminal 30 in the cover area 40, and transmits information received from the mobile terminal 30 to the backbone network 60 via the backhaul line 50, Information transmitted from the network 60 is transmitted to the mobile terminal 30. In addition, a connection attempt for determining whether or not relay communication is possible with the failed radio base station is executed.

The storage unit 22 stores a normal value 221 of transmission power, a predetermined value 222 of transmission power, and an unusable channel 223.
The normal value 221 of transmission power is a value of transmission power used when there is no failure in the backhaul line 50.
The predetermined value 222 of transmission power is a value of transmission power used when the backhaul line 50 has a failure. This predetermined value is set larger than the normal value. Note that the predetermined value 222 of the transmission power may be represented by a relational expression or a table that increases as the distance increases in accordance with the distance to another radio base station 20. .
The unusable channel 223 is a channel that is used for relay communication and is unusable.

  The input / output unit 23 has functions of an input interface for connecting an input device such as a keyboard and a mouse and an output interface for connecting a display device such as a display. The input / output unit 23 receives information input from an input device operated by a supervisor, Information such as a message prompting input is output to the display device.

  The communication unit 24 has a function of a communication interface for transmitting and receiving information via the backbone network 60.

  Next, an example of a processing sequence in the mobile communication system 1 will be described with reference to FIG. 7 (refer to FIGS. 1, 5, and 6 as appropriate). In FIG. 7, a case where a failure occurs in the backhaul line of the radio base station 20A and the radio base station 20A becomes a failure radio base station will be described as an example. In addition, it is assumed that the radio base stations 20B and 20D are selected as candidate radio base stations, and the radio base station 20B is a donor station.

In step S1, the failure detection unit 111 of the center monitoring apparatus 10 transmits arrival confirmation information to the radio base station 20A at a predetermined cycle. Actually, the arrival confirmation information is transmitted to all the radio base stations 20.
In step S <b> 2, the failure detection unit 211 of the radio base station 20 </ b> A receives the arrival confirmation information and transmits response information corresponding to the arrival confirmation information to the center monitoring apparatus 10. Actually, the response information is transmitted from all the radio base stations 20 that have received the arrival confirmation information.

In step S3, the failure detection unit 111 of the center monitoring apparatus 10 transmits arrival confirmation information to the radio base station 20A at a predetermined cycle. However, the arrival confirmation information does not arrive at the radio base station 20A due to the failure of the backhaul line 50.
Therefore, in step S4, the failure detection unit 211 of the radio base station 20A cannot receive the arrival confirmation information, and therefore does not transmit the response information corresponding to the arrival confirmation information to the center monitoring apparatus 10.

In step S5, the failure detection unit 111 of the center monitoring apparatus 10 cannot receive response information from the radio base station 20A, and therefore determines that a failure has occurred in the backhaul line 50 of the radio base station 20A, and detects the failure.
In step S6, since the failure detection unit 211 of the radio base station 20A cannot receive the arrival confirmation information from the center monitoring apparatus 10, it determines that a failure has occurred in the backhaul line 50 of the radio base station 20A, and detects the failure. . In the following sequence, the radio base station 20A having a fault in the backhaul line 50 will be described as a faulty radio base station (first radio base station).

  In step S <b> 7, the candidate radio base station selection unit 112 of the center monitoring apparatus 10 selects the candidate radio base station 20. Specifically, the candidate radio base station selection unit 112 refers to the radio base station position information 121 and reads out the latitude and longitude of the faulty radio base station, and the latitude and longitude of the radio base station 20 near the faulty radio base station. Is read. Then, the candidate radio base station selection unit 112 selects a radio base station 20 within a predetermined distance set by the supervisor as the candidate radio base station 20.

  In step S8, the transmission power control unit 212 of the failed radio base station detects the failure and then increases the transmission power to a predetermined value with reference to the predetermined value 222 of the transmission power in the storage unit 22.

In step S9, the candidate radio base station control unit 113 of the center monitoring apparatus 10 transmits an instruction to increase the transmission power to a predetermined value to the candidate radio base stations 20 (20B, 20D).
In step S10, the transmission power control unit 212 of the candidate radio base station 20 (20B, 20D) refers to the predetermined value 222 of the transmission power in the storage unit 22 and increases the transmission power to a predetermined value.

In step S11a, the candidate radio base station control unit 113 of the center monitoring apparatus 10 instructs the candidate radio base station 20D to try to connect to the faulty radio base station. In addition, it is preferable that the order of the connection trials is instructed in order from the shortest distance between the failed radio base station and the candidate radio base station 20.
In step S12a, the communication processing unit 214 of the candidate radio base station 20D executes a connection attempt.
In step S13a, the communication processing unit 214 of the candidate radio base station 20D transmits a connection failure notification to the center monitoring apparatus 10 when information cannot be transmitted / received to / from the failed radio base station. As a cause of communication failure, there may be a case where some kind of obstacle exists between the candidate radio base station 20D and the obstacle radio base station.

Since the center monitoring apparatus 10 has received the connection failure notification in step S13a, next, in step S11b, the candidate radio base station control unit 113 of the center monitoring apparatus 10 gives a fault to the candidate radio base station 20B. Instructs the wireless base station to try to connect.
In step S12b, the communication processing unit 214 of the candidate radio base station 20B executes a connection attempt.
In step S <b> 13 b, the communication processing unit 214 of the candidate radio base station 20 </ b> B transmits a connection success notification to the center monitoring apparatus 10 when information can be transmitted / received to / from the failed radio base station.

  In step S14, the candidate radio base station control unit 113 of the center monitoring apparatus 10 determines the candidate radio base station 20B that has transmitted the connection success notification first as the donor station (second radio base station). In the following sequence, the candidate radio base station 20B will be described as a donor station.

In step S15, the candidate radio base station control unit 113 of the center monitoring apparatus 10 transmits an instruction to set the transmission power to a normal value to the candidate radio base stations 20 (20D) other than the donor station.
In step S16, the transmission power control unit 212 of the candidate radio base station 20D refers to the normal value 221 of the transmission power in the storage unit 22 and returns the transmission power to the normal value.

  In step S17, the candidate radio base station control unit 113 of the center monitoring apparatus 10 instructs the candidate radio base station 20 (20D) other than the donor station to disable the use of the relay communication channel. Note that the channel control unit 213 of the candidate radio base station 20D receives an instruction to disable the use of the relay communication channel, and stores the instructed unusable channel in the unusable channel 223 of the storage unit 22.

  In step S18, the failed radio base station and the donor station execute relay communication between them.

  Next, in FIG. 8, a sequence example in which the backhaul line 50 of the failed radio base station is restored and returned to the normal mobile communication system 1 will be described.

In step S21, the failure detection unit 111 of the center monitoring apparatus 10 transmits arrival confirmation information to the failed radio base station (radio base station 20A) at a predetermined cycle. Actually, the arrival confirmation information is transmitted to all the radio base stations 20.
In step S22, the failure detection unit 211 of the failed radio base station (radio base station 20A) receives the arrival confirmation information and returns response information corresponding to the arrival confirmation information because the backhaul line 50 has been restored. To the center monitoring apparatus 10. Actually, the response information is transmitted from all the radio base stations 20 that have received the arrival confirmation information.

In step S23, since the failure detection unit 111 of the center monitoring apparatus 10 has received the response information from the failed radio base station, the failure detection unit 111 determines that there is no failure in the backhaul line 50 of the failed radio base station, and detects recovery.
In step S24, since the failure detection unit 211 of the failed radio base station has received the arrival confirmation information from the center monitoring apparatus 10, it determines that there is no failure in its own backhaul line 50 and detects recovery.

  In step S25, the candidate radio base station control unit 113 of the center monitoring apparatus 10 instructs the donor station to end the relay communication.

In step S26, the candidate radio base station control unit 113 of the center monitoring apparatus 10 transmits an instruction to set the transmission power to a normal value to the donor station.
In step S27, the transmission power control unit 212 of the donor station refers to the normal value 221 of the transmission power in the storage unit 22 and returns the transmission power to the normal value.

In step S28, the candidate radio base station control unit 113 of the center monitoring apparatus 10 instructs the candidate radio base station 20 (20D) other than the donor station to cancel the setting of the unavailable channel. The channel control unit 213 of the candidate radio base station 20 (20D) receives the relay communication channel setting cancellation instruction and deletes the unusable channel stored in the unusable channel 223 of the storage unit 22. To do. In the following sequence, the donor station will be described as the radio base station 20B, and the candidate radio base station 20 (20D) will be described as the radio base station 20D.
In step S29, the transmission power control unit 212 of the failed radio base station sets the transmission power to a normal value. In the following sequence, the failed radio base station will be described as the radio base station 20A.

  In step S30, the radio base stations 20A, 20B, 20D execute normal communication processing.

  Next, a processing flow example of the center monitoring apparatus 10 will be described with reference to FIGS. 9 and 10 (see FIGS. 1 and 5 as appropriate).

In step S901, the failure detection unit 111 determines whether a failure of the backhaul line 50 has been detected. Specifically, the failure detection unit 111 transmits arrival confirmation information to the radio base station 20 at a predetermined cycle. However, when the failure detection unit 111 cannot receive response information from the radio base station 20, the failure detection unit 111 determines that a failure has occurred in the backhaul line 50 of the radio base station 20, and detects the failure.
If it is determined that a failure has been detected (Yes in step S901), the process proceeds to step S902. If it is determined that no failure has been detected (No in step S901), the process proceeds to step S1001 in FIG.

In step S902, the failure detection unit 111 detects a failed radio base station.
In step S903, the candidate radio base station selection unit 112 selects a candidate radio base station. Specifically, the candidate radio base station selection unit 112 refers to the radio base station position information 121 and reads out the latitude and longitude of the faulty radio base station, and the latitude and longitude of the radio base station 20 near the faulty radio base station. Is read. Then, the candidate radio base station selection unit 112 selects a radio base station 20 within a predetermined distance set by the supervisor as the candidate radio base station 20.

In step S904, the candidate radio base station selection unit 112 determines whether there is a candidate radio base station 20.
If it is determined that there is a candidate radio base station 20 (Yes in step S904), the process proceeds to step S905. If it is determined that there is no candidate radio base station 20 (No in step S904), the process proceeds to step S906.

In step S905, the candidate radio base station control unit 113 transmits to the candidate radio base station 20 an instruction to increase the transmission power to a predetermined value.
In step S <b> 906, the candidate radio base station control unit 113 outputs a notification that the candidate radio base station 20 is not applicable to the display device (not illustrated) via the input / output unit 23. Then, the process ends.

  In step S907, the candidate radio base station control unit 113 sequentially instructs the candidate radio base station 20 to try to connect to the failed radio base station. In addition, it is preferable that the order of the connection trials is instructed in order from the shortest distance between the failed radio base station and the candidate radio base station 20. Further, the candidate radio base station control unit 113 receives a connection success notification or a connection failure notification from the candidate radio base station 20 that has performed the connection attempt.

In step S908, the candidate radio base station control unit 113 determines whether a connection success notification has been received.
If it is determined that a connection success notification has been received (Yes in step S908), the process proceeds to step S909. If it is determined that a connection success notification is not received, that is, if a connection failure notification is received (No in step S908), The process proceeds to step S912.

  In step S909, the candidate radio base station control unit 113 determines the candidate radio base station 20 that has transmitted the connection success notification first as a donor station.

In step S910, the candidate radio base station control unit 113 transmits an instruction to set the transmission power to the normal value to the candidate radio base stations 20 other than the donor station.
In step S911, the candidate radio base station control unit 113 instructs the candidate radio base stations 20 other than the donor station to disable the use of the relay communication channel. Then, the process returns to step S901.

In step S912, the candidate radio base station control unit 113 determines whether there is a candidate radio base station whose connection attempt has not been processed.
If it is determined that there is an unprocessed candidate radio base station for the connection attempt (Yes in step S912), the process proceeds to step S907, and if it is determined that there is no unprocessed candidate radio base station (in step S912). No), the process proceeds to step S913.

  In step S <b> 913, the candidate radio base station control unit 113 determines that there is no candidate radio base station 20 that has been successfully connected, and outputs a notification of no match to the display device (not illustrated) via the input / output unit 23. To do. Then, the process ends.

  Moving to FIG. 10, in step S1001, the failure detection unit 111 determines whether recovery of the backhaul line 50 of the failed radio base station has been detected. Specifically, the failure detection unit 111 determines that there is no failure in the backhaul line 50 of the failed radio base station when the arrival confirmation information is transmitted to the failed radio base station and response information is received from the failed radio base station. , Detect recovery.

  If it is determined that recovery has been detected (Yes in step S1001), the process proceeds to step S1002. If it is determined that recovery has not been detected (No in step S1001), the process returns to step S901 in FIG.

In step S1002, the candidate radio base station control unit 113 instructs the donor station to end relay communication.
In step S1003, candidate radio base station control section 113 transmits an instruction to set the transmission power to a normal value to the donor station.

  In step S1004, the candidate radio base station control unit 113 instructs the candidate radio base stations 20 other than the donor station to cancel the setting of the unavailable channel.

  As described above, in the mobile communication system 1 according to the present embodiment, (1) the center monitoring apparatus 10 detects the radio base station 20 (failed radio base station) in which a failure has occurred in the backhaul line 50, and (2) troubled radio Since the base station communicates with the neighboring radio base station 20, the transmission power is increased to a predetermined value larger than the normal value, and (3) the candidate that becomes the candidate for the center monitoring apparatus 10 to communicate with the failed radio base station The radio base station is selected, and an instruction to increase the transmission power to a predetermined value larger than the normal value is issued to the candidate radio base station. (4) The candidate radio base station tries to connect to the failed radio base station, (5) A candidate radio base station (donor station) that has succeeded in connection transmits / receives information (relay communication) to / from the failed radio base station, and (6) the center monitoring apparatus 10 is a candidate radio other than the donor station. Transmit power to the base station. An instruction to return to the value and an instruction to disable (use prohibition) of the channel used in the relay communication are issued. (7) When the backhaul line 50 is restored, the center device 10 instructs to end the relay communication. An instruction to return the transmission power to the normal value and an instruction to cancel the setting of the unusable channel are issued. Since the mobile communication system 1 has such a configuration and method, when a failure occurs in the backhaul line 50 of the radio base station 20 and communication becomes impossible, the communication service is prevented from being interrupted. Is possible.

  In addition, although demonstrated as what complete | finishes a process after step S906 of FIG. 9, the distance set in order to select the candidate radio base station 20 by the supervisor is changed into a larger distance, and step S903 ( You may make it return to selection of a candidate radio base station.

DESCRIPTION OF SYMBOLS 1 Mobile communication system 10 Center monitoring apparatus 11 Processing part 12 Storage part 13 Input / output part 14 Communication part 20, 20A, 20B, 20C, 20D Wireless base station 21 Processing part 22 Storage part 23 Input / output part 24 Communication part 30, 30A , 30B, 30D Mobile terminal 40, 40A, 40B, 40C, 40D Cover area 50 Backhaul line 60 Core network 111 Failure detection unit 112 Candidate radio base station selection unit 113 Candidate radio base station control unit 121 Radio base station position information 211 Failure Detection unit 212 Transmission power control unit 213 Channel control unit 221 Normal value of transmission power 222 Predetermined value of transmission power 223 Unusable channel

Claims (12)

A mobile unit comprising a plurality of radio base stations that transmit / receive information to / from a mobile terminal carried by the mobile unit, and a center monitoring device that is connected via a backhaul line of the radio base station and controls the radio base station A communication system,
The radio base station is
When the arrival confirmation information is received from the center monitoring device at a predetermined cycle, response information to the arrival confirmation information is transmitted to the center monitoring device, and the backhaul line is faulty when the arrival confirmation information is not received. A failure detection unit that determines that an error occurred;
A transmission power control unit that increases the transmission power to a predetermined value larger than a normal value when it is determined that a failure has occurred in the backhaul line;
The center monitoring device
When the backhaul line is faulty when the arrival confirmation information is transmitted to the wireless base station at a predetermined cycle and the response information corresponding to the arrival confirmation information is not received from the wireless base station. A failure detecting unit that determines the wireless base station in which the failure has occurred as a first wireless base station;
A candidate base station that increases the transmission power of the neighboring radio base station by transmitting an instruction to increase the transmission power to a predetermined value larger than a normal value to the neighboring radio base station of the first radio base station A control unit;
Among the neighboring radio base stations that are able to communicate with the first radio base station that has selected the neighboring radio base station based on a predetermined criterion and increased the transmission power to a predetermined value that is larger than a normal value. A candidate radio base station selector that uses one of the second radio base stations as a second radio base station;
With
The mobile communication system, wherein the second radio base station performs relay communication of information transmitted and received by the first radio base station with the mobile terminal. 2. The movement according to claim 1, wherein the candidate base station control unit transmits an instruction to return transmission power to a normal value to the neighboring radio base stations other than the second radio base station. Body communication system. The candidate radio base station selector is
3. The movement according to claim 1, wherein when selecting the neighboring radio base station, the neighboring radio base station is selected based on a distance from the first radio base station. 4. Body communication system. The candidate base station controller
When performing relay communication between the first radio base station and the second radio base station using a time division multiplexing channel,
4. An instruction for disabling a channel used for the relay communication is transmitted to the neighboring radio base stations other than the second radio base station. The mobile communication system according to item. A mobile unit comprising a plurality of radio base stations that transmit / receive information to / from a mobile terminal carried by the mobile unit, and a center monitoring device that is connected via a backhaul line of the radio base station and controls the radio base station A detour route construction method for a communication system,
The radio base station is
When the arrival confirmation information is received from the center monitoring device at a predetermined cycle, response information to the arrival confirmation information is transmitted to the center monitoring device, and the backhaul line is faulty when the arrival confirmation information is not received. A failure detection step for determining that a problem has occurred;
When it is determined that a failure has occurred in the backhaul line, a transmission power control step of increasing the transmission power to a predetermined value larger than a normal value is performed,
The center monitoring device
When the backhaul line is faulty when the arrival confirmation information is transmitted to the wireless base station at a predetermined cycle and the response information corresponding to the arrival confirmation information is not received from the wireless base station. Determining a failure detecting step in which the wireless base station where the failure has occurred is the first wireless base station;
A candidate base station that increases the transmission power of the neighboring radio base station by transmitting an instruction to increase the transmission power to a predetermined value larger than a normal value to the neighboring radio base station of the first radio base station Control steps;
Among the neighboring radio base stations that are able to communicate with the first radio base station that has selected the neighboring radio base station based on a predetermined criterion and increased the transmission power to a predetermined value that is larger than a normal value. A candidate radio base station selection step with one of the second radio base stations as one of
Transmitting an instruction to return the transmission power to a normal value to the neighboring radio base stations other than the second radio base station; and
The second radio base station relay-communications information transmitted and received by the first radio base station with the mobile terminal. In the candidate base station control step,
6. The detour path construction method according to claim 5, wherein an instruction to return transmission power to a normal value is transmitted to the neighboring radio base stations other than the second radio base station. In the candidate radio base station selection step,
The detour according to claim 5 or 6, wherein when selecting the neighboring radio base station, the neighboring radio base station is selected based on a distance from the first radio base station. Route construction method. In the candidate base station control step,
When performing relay communication between the first radio base station and the second radio base station using a time division multiplexing channel,
8. An instruction for disabling a channel used for the relay communication is transmitted to the neighboring radio base stations other than the second radio base station. The detour route construction method according to the item. A center monitoring apparatus that is connected to a mobile terminal carried by a mobile body via a backhaul line with a plurality of radio base stations that transmit and receive information, and controls the radio base station,
When the backhaul line is faulty when the arrival confirmation information is transmitted to the wireless base station at a predetermined cycle and the response information corresponding to the arrival confirmation information is not received from the wireless base station. A failure detecting unit that determines the wireless base station in which the failure has occurred as a first wireless base station;
A candidate base station that increases the transmission power of the neighboring radio base station by transmitting an instruction to increase the transmission power to a predetermined value larger than a normal value to the neighboring radio base station of the first radio base station A control unit;
Among the neighboring radio base stations that are able to communicate with the first radio base station that has selected the neighboring radio base station based on a predetermined criterion and increased the transmission power to a predetermined value that is larger than a normal value. A candidate radio base station selector that uses one of the second radio base stations as a second radio base station;
With
The center monitoring apparatus, wherein the second radio base station performs relay communication of information transmitted and received by the first radio base station with the mobile terminal. The center according to claim 9, wherein the candidate base station control unit transmits an instruction to return transmission power to a normal value to the neighboring radio base stations other than the second radio base station. Monitoring device. The candidate radio base station selector is
The center according to claim 9 or 10, wherein when selecting the neighboring radio base station, the neighboring radio base station is selected based on a distance from the first radio base station. Monitoring device. The candidate base station controller
When performing relay communication between the first radio base station and the second radio base station using a time division multiplexing channel,
12. An instruction for disabling a channel used for the relay communication is transmitted to the neighboring radio base stations other than the second radio base station. The center monitoring device according to item.

Images