JP5355304B2 - Communication system and communication method - Google Patents

Description

  The present invention relates to a communication system and a communication method, and more particularly to a technique for dealing with a failure in a communication data transmission path.

  Conventionally, in a wireless communication system, each of a plurality of base stations is connected to a higher-level device (for example, a network control device) via a relay line called a backhaul. In such a wireless communication system, a failure such as data congestion may occur between the base station and the host device. However, the user of the wireless terminal connected to the base station cannot grasp that a failure has occurred. For this reason, a technique has been proposed in which a base station notifies a wireless terminal that is connecting or trying to connect that a failure has occurred (for example, Patent Document 1).

JP 2007-259033 A

  Currently, wireless backhaul using wireless communication is being adopted for the purpose of reducing line installation costs and line usage fees. In this case, the transmission / reception of data in the backhaul is less stable than that of the wired line, and each base station is forced to respond according to the situation. However, in the above-described wireless communication system, only the failure occurrence is notified to the lower-level wireless terminal, and after the failure occurs, the response to the failure, for example, the disconnection of the wireless link with the wireless terminal is performed. It has only been done.

  The present invention has been made in view of such problems, and an object of the present invention is to detect a situation where a failure is likely to occur, and to take countermeasures to prevent the occurrence of a failure. An object of the present invention is to provide a communication system and a communication method that can reduce the influence on users.

  In order to achieve the above object, the present invention is a communication system comprising a radio base station that communicates with a radio terminal, and a relay device that relays data transmitted and received between the radio base station and a host device. The radio base station includes a radio communication unit that communicates with the radio terminal, a first communication unit that communicates with the relay device, and the relay device between the relay device and the higher-level device. A control unit that controls communication with the wireless terminal based on the failure information when failure information related to a failure in an upper network is received via the second communication unit, and the relay device Includes a second communication unit that performs wireless communication with the higher-level device, a generation unit that detects a failure in the higher-level network and generates failure information related to the failure, and the generated failure information is transmitted to the wireless base station To the station Characterized in that it comprises a transmitter which transmits the.

  Thus, by detecting a situation where a failure is likely to occur and taking countermeasures, the influence on the user can be reduced even if a failure actually occurs.

  Further, in the communication system according to the present invention, the relay apparatus detects a failure in a wireless connection portion between the relay apparatus and the host device as the failure information, and the wireless base station receives the failure information after receiving the failure information. And a storage unit that stores data received from the wireless terminal and received from the wireless terminal.

  In the communication system according to the present invention, in the wireless base station, when the failure information is received, the control unit transmits information indicating the end of communication with the wireless terminal after a predetermined time has elapsed. It transmits to the said radio | wireless terminal via a communication part, It is characterized by the above-mentioned.

  In the communication system according to the present invention, when the relay device receives failure information from another upper relay device between the relay device and the upper device via the second communication unit, In the radio base station, the transmission unit transmits fault information of the other relay device to the radio base station.

  In order to achieve the above object, the present invention provides a communication method of a communication system comprising a radio base station that communicates with a radio terminal, and a relay device that is connected to the radio base station and radioly connected to a higher-level device. The relay device detects a failure in an upper network including a wireless connection portion with the upper device, generates failure information related to the failure, and generates the failure information as the wireless base station. Transmitting to a station, the radio base station receiving the failure information from the relay device, and controlling communication with the wireless terminal based on the failure information It is characterized by that.

  By detecting a situation where a failure is likely to occur and taking countermeasures, the influence on the user can be reduced even if a failure actually occurs.

1 is a schematic configuration diagram illustrating a communication system according to an embodiment of the present invention. It is the functional block diagram which showed the structure of the radio base station and the relay apparatus of the communication system which concerns on embodiment of this invention. It is the figure which showed the failure information in the communication system which concerns on embodiment of this invention. It is the figure which showed operation | movement in the communication system which concerns on embodiment of this invention.

Next, an embodiment of the present invention will be described with reference to the drawings.
(1) Configuration of communication system
First, the configuration of the communication system according to the present embodiment will be described.
(1.1) Overall schematic configuration
FIG. 1 is a schematic configuration diagram of a communication system according to the present embodiment. As illustrated in FIG. 1, the communication system 10 includes a radio base station 100, a relay device 200 (200A to 200C), a radio terminal 300 (300X, 300Y), a network 400, an EMS server, and the like.
(1.2) Configuration of communication system
FIG. 2 is a functional block diagram illustrating configurations of the base station 100 and the relay apparatus 200 included in the communication system according to the present embodiment.
(1.2.1) Configuration of Radio Base Station As shown in FIG. 2, the radio base station 100 includes an antenna 101, a radio communication unit 102, a buffer unit 103, a storage unit 104, a failure information detection unit 105, and a radio control unit. 106, and a higher-level communication unit 107.

  The wireless communication unit 102 transmits and receives data with the wireless terminal 300 using the antenna 101.

  The buffer unit 103 temporarily stores data in order to control the order of received data at the time of data reception. The buffer unit 103 temporarily stores the data until the data transmission is completed at the time of data transmission.

  The storage unit 104 stores radio resource management information as information necessary for the operation of the radio control unit 106. The radio resource management information is information for managing radio resources that can be provided by the radio base station 100. This information includes the number of radio communication channels that can be allocated, the remaining expansion buffer amount that can be allocated, and the like. The storage unit 104 also stores information related to countermeasures when the failure information is received.

  When the failure information detection unit 105 receives failure information from any relay device 200 that is a higher-level device, the failure information detection unit 105 instructs the radio control unit 106 to take measures against the failure from the content of the failure information.

  The wireless control unit 106 performs control related to wireless communication with the wireless terminal 300. For example, a modulation scheme to be set is determined according to radio quality during radio communication with the radio terminal 300, or a radio communication channel is assigned to the radio terminal 300 that has made a connection request. Further, when the failure information detection unit 105 detects the reception of the failure information, the failure information detection unit 105 grasps the content of the failure information and responds in wireless communication with the wireless terminal 300 (details will be described later).

The upper communication unit 107 transmits / receives data to / from the relay device 200.
(1.2.2) Management server configuration
As illustrated in FIG. 2, the relay device 200 includes a lower-level communication unit 201, a failure detection unit 202, a failure information generation unit 203, and a higher-level communication unit 204.

  The lower-level communication unit 201 transmits / receives data to / from a lower-level device, for example, the radio base station 100 or the relay device 200.

  The failure detection unit 202 detects the possibility of occurrence of a failure and the occurrence of a failure in the communication line between the relay device 202 and the host device (details will be described later). On the other hand, the case where the possibility of the occurrence of the failure in the communication line is eliminated or the recovery from the failure is also detected.

  The failure information generation unit 203 generates failure information related to the detected content when the failure detection unit 202 detects the possibility of occurrence of a failure and the occurrence of a failure. Further, when the failure detection unit 202 eliminates the possibility of a failure in the communication line or detects recovery from the failure, it generates recovery information.

The higher-level communication unit 204 transmits and receives data to and from a higher-level device, for example, the relay device 200 positioned at a higher level.
(2) Possibility of failure occurrence, and detection and countermeasure of failure
Next, the possibility of occurrence of a failure in the relay apparatus 200, the detection of the failure, and countermeasures in the radio base station 100 of the communication system 10 according to the present embodiment will be described with reference to FIG.

  The failure detection unit 202 of the relay device 200 monitors the communication status on the communication line between the relay device 200 and the host device. For example, the number of wireless terminals 300 that are connected to a plurality of lower radio base stations 100 based on the amount of communication data in the communication line and the data to be communicated, and are the transmission source or transmission destination of data transmitted to and received from the upper apparatus. The communication contents (voice communication, data communication) and the like of each wireless terminal are monitored. Then, an average for each time is calculated from the monitored information, and the calculated information is held in advance.

  The failure detection unit 202 compares the stored information with the current communication status, and detects the possibility of failure occurrence and failure detection. When the failure detection unit 202 detects that a failure may occur, the failure information generation unit 203 is notified of the failure content that may occur and the level of the failure that may occur. The failure information generation unit 203 that has been notified generates failure information based on the notification content.

  FIG. 3A is a diagram illustrating a relationship between the detected content generated in the failure information generation unit 203 of the relay device 200 and the failure information indicating a level corresponding to the detected content.

  For example, the failure detection unit 202 may cause congestion when the amount of communication data at a certain time is larger than the average and approaches the amount of data that can be transmitted / received via the communication line. From the difference from the average communication data amount, the failure information generation unit 203 is notified of the level at which the congestion may occur.

  Further, the failure detection unit 202 has a larger number of accommodated wireless terminals 300 connected to a plurality of lower radio base stations 200 than the average accommodated number at a certain time, and further, the communication of each wireless terminal 300 is performed. When the amount of data that can be transmitted / received through the communication line in the future is to be squeezed from the type, the failure information generating unit 203 is notified of a level at which data transmission / reception may be congested on the upper communication line.

  Further, the failure detection unit 202 does not transmit data from the communication line with the higher-level device for a certain period of time even though there are wireless terminals 300 connected to the plurality of lower-level wireless base stations 200. Then, it is determined that the communication line with the higher-level device has been disconnected, and the failure information generation unit 203 is notified that a failure has been detected.

  Further, the failure detection unit 202 notifies the failure information generation unit 203 of a level such as a data error that has occurred and an increase rate of the error rate when the data error or the error rate has increased in the upper communication line. To do.

  Furthermore, if the voltage drop occurs in the relay device 202, the failure detection unit 202 determines that a failure may occur, and notifies the failure information generation unit 203 of the level related to the voltage drop that has occurred.

  On the other hand, when the failure information detecting unit 105 detects that the failure information is received, the wireless control unit 106 of the wireless base station 100 grasps the content of the failure information. Then, according to the contents of the failure information, any countermeasure stored in advance in the storage unit 104 is selected and the communication with the wireless terminal 300 is controlled.

  FIG. 3B is a diagram illustrating information related to countermeasures when failure information is received, which is stored in the storage unit 104. FIG. 3B shows the relationship between the contents relating to the failure information and the countermeasure to be selected.

  For example, when there is a possibility of congestion as described above, the amount of data transmitted to the higher-level relay device 200 can be reduced by limiting the modulation method in the wireless communication with the wireless terminal 300, or the line If there is a possibility of congestion, the buffer amount of the buffer unit allocated to the wireless communication with each wireless terminal 300 is ensured by an amount according to the notified level together with the content with each possible failure, To expand. In addition, when a data error or an error rate is increased in a higher-level communication line, a modulation method for transmitting data received from the wireless terminal 300 to the relay device 200 is limited.

On the other hand, when the communication line with the host device is disconnected and a failure has occurred, the wireless link with the wireless terminal 300 is temporarily held, and then the wireless link is disconnected after a predetermined time.
(3) Operation of communication system 10
Next, operations of the radio base station 100 and the relay device 200 in the communication system 10 according to the present embodiment will be described.

FIG. 4 is a diagram illustrating operations in the radio base station 100 and the relay apparatus 200.
In step S41, the relay device 200 detects the possibility of failure on the communication line with the host device. In step S42, the relay device 200 generates failure information related to the detected content. In step S43, the relay apparatus 200 transmits the generated failure information to the radio base station 100. In step S44, the relay device 200 determines whether or not the communication line with the host device has been restored. As a result of the determination, when it is recovered (corresponding to step S44 Yes), the process proceeds to step S45. On the other hand, if not recovered (corresponding to No in step S44), the process proceeds to step S44. In step S <b> 45, the relay device 200 generates recovery information and transmits it to the radio base station 100.

  In step S51, the radio base station 100 receives the failure information from the relay device 200. In step S52, the radio base station 100 determines whether or not the received failure information is content related to the possibility of failure occurrence. If the content is related to the possibility of failure occurrence (corresponding to Yes in step S52), the process proceeds to step S53. On the other hand, if the content relates to the occurrence of a failure (corresponding to step S52 No), the process proceeds to step 57.

  In step S53, when the received failure information is content related to the possibility of failure occurrence, the radio base station 100 selects a countermeasure. In step S54, the radio base station 100 implements the selected countermeasure (buffer expansion) in the radio communication with the radio terminal 300. In step S55, the radio base station 100 notifies the radio terminal 300 that there is a possibility of failure occurrence (deterioration of communication quality) in the upper communication line (backhaul). In step S56, when the radio base station 100 recognizes that the upper communication line has been restored, the radio base station 100 cancels the currently implemented countermeasure.

  In step S57, the radio base station 100 temporarily holds a radio link with the radio terminal 300 when the received fault information is content related to the occurrence of the fault. In step S58, the radio base station 100 temporarily stores, in the buffer unit 103, data received from the radio terminal 200 and data to be transmitted to the radio terminal 200. In step S59, when the radio base station 100 recognizes that the upper communication line has been restored (equivalent to step S59 Yes), the radio base station 100 proceeds to step S56. On the other hand, if there is no change in the upper communication line (corresponding to step S59 No), in step S60, the radio base station 100 indicates that the radio link with the radio base station 100 is disconnected after a predetermined time has elapsed. The terminal 200 is notified. In step S61, the radio base station 100 disconnects the radio link with the radio terminal 200 after a predetermined time has elapsed.

  Although the present invention has been described with reference to the drawings and examples, it should be noted that those skilled in the art can easily make various variations and modifications based on the present disclosure. Note that it is within the scope of the invention. For example, functions included in each component, each step, and the like can be rearranged so as not to be logically contradictory, and a plurality of means and steps can be combined into one or divided. is there.

DESCRIPTION OF SYMBOLS 10 ... Communication system 100 ... Wireless base station 101 ... Antenna 102 ... Wireless communication part 103 ... Buffer part 104 ... Memory | storage part 105 ... Fault information detection part 106 ... Radio | wireless control part 107 ... High-order side communication part , 200... Relay device, 201... Lower side communication unit, 202... Fault detection unit, 203 .. fault information generation unit, 204 .. upper side communication unit, 300.

Claims (5)

A communication system comprising a radio base station that communicates with a radio terminal, and a relay device that relays data transmitted and received between the radio base station and a host device,
The radio base station is
A wireless communication unit for communicating with the wireless terminal;
A first communication unit that communicates with the relay device;
When failure information related to a failure in a higher-level network between the relay device and the higher-level device is received from the relay device via the second communication unit, the wireless terminal is based on the failure information. A control unit for controlling communication with
The relay device is
A second communication unit that performs wireless communication with the host device;
A generator that detects a failure in the upper network and generates failure information related to the failure;
A transmission unit for transmitting the generated failure information to the radio base station;
A communication system comprising: The relay device detects a failure in a wireless connection portion between the relay device and the host device as the failure information,
The radio base station is
A storage unit for storing data from the wireless terminal received by the wireless communication unit after receiving the failure information;
The communication system according to claim 1. In the radio base station,
The controller is
When the failure information is received, after a lapse of a predetermined time, information indicating the end of communication with the wireless terminal is transmitted to the wireless terminal via the wireless communication unit.
The communication system according to claim 2. When the relay device receives failure information from another upper relay device between the relay device and the higher-level device via the second communication unit,
In the radio base station,
The transmitter transmits failure information of the other relay device to the radio base station;
The communication system according to any one of claims 1 to 3, characterized in that: A communication method of a communication system comprising a wireless base station that communicates with a wireless terminal, and a relay device that is connected to the wireless base station and wirelessly connected to a host device,
The relay device is
Detecting a failure in an upper network including a wireless connection portion with the upper device, and generating failure information related to the failure;
Transmitting the generated failure information to the radio base station;
The radio base station is
Receiving the failure information from the relay device;
Controlling communication with the wireless terminal based on the failure information;
A communication method characterized by comprising:

Images