JP2005340993A - Method for detecting and restoring abnormality of base station - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect and restore the abnormality of a base station even when the base station cannot detect the abnormality of its own station by its own abnormality detecting function. <P>SOLUTION: A circuit controller controls all terminal stations place-registered in either communication area of following base stations so that routine monitor requests are transmitted successively from the following all base stations in a routine monitor processing 110. The circuit controller monitors returns from any base stations of routine monitor responses from the terminal stations to the routine monitor requests at every monitor period (one min timer at a step 117). When there is the base station, which relays the routine monitor response and does not return the response even at one time until a time is up after a 10 min timer is started, the circuit controller forcibly resets the base station and an operation is restored. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a base station abnormality detection and recovery method, and more particularly to a base station abnormality detection and recovery suitable for a radio system in which a radio channel between a base station and a terminal station is multiplexed by a TDM (time division multiplexing) method. It is about the method.

  FIG. 4 is a block diagram showing an example of a communication system targeted by the present invention. In each of the lower devices 4, 4,..., An exchange (PBX) and a telephone (TEL), a server and a personal computer (PC) are installed. Connected to the network 8. Each of the lower devices 4, 4... Is also provided with a semi-fixed station as a call terminal station, and this terminal station is movable and communicates with any of the base stations 3, 3. Can do.

  The base stations 3, 3... Are composed of an active system (N system: Normal) and a standby system (E system: Emergency). If either system is normal, communication can be continued without interruption. . The radio line between the terminal stations is multiplexed by the TDM method, and a plurality of call channels and one control channel are configured.

  The line control device 1 performs state monitoring, call processing control, and the like of the base stations 3, 3..., And the call signal and control signal are time-division multiplexed by the multiplexing device 2 and sent to the corresponding base station 3. The multiplexed signals from the respective base stations are separated by the multiplexer 2 and sent to the line controller 1. The line control device 1 is connected to the network 8 via the exchange (PBX) 5, the server 6, etc., and is configured to be able to communicate with the lower devices 4, 4,... Via the network. The maintenance console 7 is provided to perform maintenance work for each part of the system via the line control device 1. Such a communication system is used, for example, as a disaster prevention radio system of a local government.

  In the system of FIG. 4, since the base station and the terminal station are time-division multiplexed, at least the line control apparatus 1, the multiplexing apparatus 2, and the base stations 3, 3,. For this purpose, the clock signal provided in the multiplexing device 2 is used as a master for the synchronization signal, and the line control device 1 and the base stations 3, 3,. It performs channel slot timing generation for division multiplexing.

  Each of the base stations 3, 3... Is provided with a device for detecting an abnormality of the own station (not shown). For example, when any abnormality is detected in the active system, switching to the standby system is performed to continue communication. In addition, an abnormal signal is transmitted to the line control device 1. However, depending on the abnormality of the base station, it may be impossible to detect the abnormality and control associated therewith, such as a failure of the abnormality detection device itself of the own station. Further, an exchange (PBX) 5 is connected to the upstream side of the line control device 1 in FIG. 4, and if the transmission path between the multiplexing device 2 and the base station 3 is a microwave relay system or the like, When a disturbance such as a temporary stop of the synchronization signal from the multiplexer occurs due to a lightning strike or maintenance work on the device, the line controller 1, the multiplexer 2, the base station 3, etc. The synchronization signal is recovered, and the line control device and the base station recover the operation synchronized with the synchronization signal. However, if there is a change in the line state before and after the disturbance of the synchronization signal, normal line control may not be performed.

As a countermeasure when the abnormality of the own station cannot be detected by the function of the base station itself, there is a known technique described in Patent Document 1. In this known technique, a device for constantly observing transmission / reception of information between a switching device upstream of the line control device and a base station on the downstream side is provided in the line control device, and the transmission / reception of the information is abnormal. Therefore, it is determined that a failure has occurred, and processing such as billing stop or initial setting of the busy line is performed on the switching device side, and it is possible to cope with a case where an abnormality cannot be detected by the base station itself.
Japanese Patent Laid-Open No. 2-62188

  In the above-described known technique, whether information transmitted / received between the switching apparatus and the base station is normally monitored or not is constantly monitored. However, there are various types of information to be monitored and abnormalities in the base station. There is no specific description such as what kind of information and what kind of information is detected. In addition, since information corresponding to an abnormal situation is not always transmitted / received via the line control device, abnormality detection is impossible in such a case.

  In the system shown in FIG. 4 described above, for example, due to a lightning strike or any other cause, both the active system and the standby system of the base station operate to output radio signals of the same frequency, and the radio link between the terminal stations can be used. It may disappear. In addition, if the base station cannot detect such an abnormality by itself, the line control device cannot detect and deal with the abnormality. In such a case, even with the above-described known technique, there is no description about the presence or content of information to be detected and the contents cannot be dealt with.

  The object of the present invention is not to passively monitor the flow of information, but to periodically output a monitoring signal from the line control device to detect abnormality of the base station that cannot be detected by the base station confidence and An object of the present invention is to provide an abnormality detection and recovery method that enables recovery processing.

The present invention relates to a plurality of base stations that communicate with a mobile terminal station via a time-division-multiplexed radio line, a line having a function of monitoring the status of these base stations and a call processing control function of each terminal station. A control device, and a multiplexing device installed between the line control device and the plurality of base stations to multiplex / separate communication signals and supply synchronization signals to the line control device and the base station A base station anomaly detection and recovery method in a closed system,
The line control device sequentially sends periodic monitoring requests to all the terminal stations registered in one of the communication areas of the plurality of base stations at every preset monitoring cycle. A periodic monitoring response from the terminal station to the periodic monitoring request via the base station is controlled to transmit, and the periodic monitoring response from the terminal station is set during a threshold time set larger than the monitoring cycle. A base station abnormality detection and recovery method is disclosed in which if there is a base station that has not relayed any of the base stations, the base station is determined to be abnormal, and the base station is reset by the line control device.

  If a transmission / reception system abnormality from the base station to the terminal station occurs, transmission / reception between the base station and the terminal station becomes impossible, and a periodic monitoring response is returned from the base station. There is no. Even if there is no terminal station in the communication area, the periodic monitoring response is not sent back, but if the threshold time is set sufficiently large, the probability of such occurrence will be small, and in most cases an abnormality will occur. It can be judged.

  Embodiments of the present invention will be described below. 1 to 3 are flowcharts showing an example of a processing system provided in the line control apparatus 1 for realizing the base station abnormality detection and recovery method according to the present invention. In this process, a periodic monitoring function provided in the system of FIG. 4 is used. In this periodic monitoring function, the line control apparatus 1 periodically transmits a periodic monitoring request to each terminal station via the control channel, and checks the periodic monitoring response via the control channel from each multiplexing apparatus. The status of each base station is checked.

  The main part of this processing system transmits the above periodic monitoring request to each terminal station through the control channel at a predetermined monitoring cycle, and checks the periodic monitoring response thereto. If there is a base station that has not returned a periodic monitoring response from any terminal station during a threshold (time) set larger than the above period, the base station determines that the base station is abnormal and The line control device is reset. The operation of the flowcharts of FIGS. 1 to 3 for executing such processing will be described below.

  FIG. 1 is a main flow of this processing system. In this process, a 10-minute timer is used with the threshold being 10 minutes, and a 1-minute timer is used with a predetermined monitoring period of 1 minute. Also, a reset flag Fj indicating whether the base station has been reset by this processing is used. A 10-minute timer and a reset flag are provided for each base station, but the 1-minute timer is shared by all base stations. Although this main flow is always operating, the reset flag of all base stations is set to “false” at the start of processing (step 101), and the 10-minute timer for all base stations is reset (with start: And the 1 minute timer is reset (with start: the same applies below) (steps 102 and 103). Next, steps 105 and 106 and reset processing 107 are executed for each base station under the control of the line control device 1 (control of loop C by steps 104 and 109). That is, the base stations 3, 3... Under the line control device are represented as BTSj (j = 1, 2...), And the number Cj of terminal stations under the base station BTSj is first counted (step 105). Here, the “terminal station under control” is a terminal station that has registered its location within the communicable area of the base station BTSj, and this location registration information is stored in a memory in the line control device 1. ing. When the number of subordinate terminal stations Cj is not 0, the reset process 107 in FIG. 2 is executed for the base station BTSj. Note that the reset flag Fj for which “false” is set in step 101 corresponds to BTSj (j = 1, 2,...).

  FIG. 2 is a flowchart showing details of the reset process. First, it is checked whether the reset flag Fj of the base station is “true” (step 201). At the start of the main processing, since Fj is set to “false” in step 101, “No” is set. It is checked whether the 10-minute timer corresponding to the base station BTSj is up (step 202). Here, if it is within 10 minutes after starting at step 102, the reset process is terminated with "No". If 10 minutes or more have elapsed, the reset flag Fj of the base station BTSj is set to "true". Thereafter, the base station is reset, and the corresponding 10-minute timer is reset and started again (steps 202, 203, and 204).

  When the processing of the loop C is finished, the regular monitoring processing 110 shown in FIG. 3 is executed. In this process, similarly to loop C in FIG. 1, steps 302 to 308 are executed for each base station BTSj (j = 1, 2,...) Subordinate to the line control apparatus 1 (control of loop A by steps 301 and 309). ). That is, one base station BTSj is taken out, and if there is a terminal station currently communicating with the base station (“Yes” in step 302), the number Cj of subordinate terminal stations given by loop C in FIG. (Step 303), the base station processing ends. Here, Cj is set to 0 in order to prevent the base station BSTj from being normal if there is a terminal station in a call, and to prevent the base station from being reset in subsequent processing by setting Cj to 0.

  If there is no terminal station currently in a call (“No” in step 302), the processes in steps 305 to 307 are executed at intervals of 2 seconds for each terminal station whose location is registered as being under the base station. (Control of loop B by 304 and 308). That is, the C C terminal stations under the base station BTSj extracted in the loop A are taken out one by one, and periodic monitoring requests for the terminal stations are sent from all the base stations under the line controller 1 all at once. Transmit (steps 304 and 305). If the periodic monitoring response to the periodic monitoring request is returned from the base station BTSk, the number Ck of terminal stations registered as being under the base station BSTk is set to 0 (step 307). Here, Cj terminal stations registered as being under the base station BTSj may be moved under another base station when the periodic monitoring process is executed after the time point Cj is obtained in step 105 of the main process. In step 305, a periodic monitoring request is transmitted from all base stations, and when the response is returned via the base station BTSk (k may be equal to or different from j), the response is normally received. The received base station BTSk is regarded as normal, and its Ck is set to 0 as in step 303.

  When the regular monitoring process 110 in the main process is completed, the processes of steps 112 to 115 are executed for each base station under the control of the line control device 1 (control of loop D by steps 111 and 116). That is, first, one base station BTSj is taken out and it is checked whether Cj corresponding to the base station is 0 (step 112). When Cj = 0, the base station BTSj has a terminal station in a call, has received a regular monitoring response from the terminal station normally during regular monitoring processing, or has a subordinate terminal station of 0, both of which are The station BTSj assumes that it is normal at this time and sets “false” to the reset flag Fj of the base station again (step 113), and resets and starts the corresponding 10-minute timer (step 114). If Cj is not 0 (“No” in step 112), the reset process 115 of FIG. 2 described above is executed.

  When the processing of loop D is completed, the process waits for the one-minute timer reset / started in step 103 to time out (step 117), and when time is up, the processing returns to step 103 to perform loop C, periodic monitoring processing, and processing of loop D. repeat.

  1 to 3 described in detail above, if the base station BTSj in which one or more terminal stations are registered is abnormal, the reset process 107 is performed with Cj> 0. Or 115 is executed. If the abnormal state continues for 10 minutes or more, the time-up of the 10-minute timer is detected in any one of these reset processes (Yes in Step 202), and the base station is reset (Step 203). This resetting of the base station eliminates abnormalities in the operation of the base station by erasing the stored connection information and releasing the corresponding call channel, etc., using the active / protection system switching process as the active process. As a result, normal operation can be recovered.

  When a terminal station (semi-fixed station) is started up and then moved out of the communication area without being used, the location registration information of the terminal station remains in the memory. At this time, the Cj value of the registered base station is not 0. However, since the terminal station is not in use, the terminal station does not respond to the periodic monitoring process, and Cj> 0 remains in the loop C and the periodic monitoring process. Loop D is repeated every minute. In this case, if no other terminal station exists in the base station, the base station is reset when 10 minutes have elapsed. In addition, if there is no terminal station newly registered in the base station, this reset is repeatedly generated every 10 minutes. The reset flag Fj is provided to prevent this repeated reset. That is, in the reset process of FIG. 2, whenever a base station BTSj is reset in step 203, “true” is set to the reset flag Fj corresponding to the base station in step 202. When the process is executed, “Yes” is given in step 201, and even if the above state continues in the base station, it is not repeatedly reset every 10 minutes. Further, since “false” is set in the corresponding reset completed flag for the base station once regarded as normal in step 113, it can be reset in the event of an abnormality thereafter.

  In the above description, a system using a semi-fixed station that can move is targeted. However, the present invention can also be applied to a system using a mobile device in place of the semi-fixed station, in particular, a business system. .

It is a flowchart which shows the example of the processing system which implement | achieves the method of this invention. FIG. 2 is a detailed view of reset processing in FIG. 1. FIG. 2 is a detailed view of a regular monitoring process in FIG. 1. It is a block diagram which shows the example of the radio | wireless system made into the object of this invention.

Explanation of symbols

1 Line Controller 2 Multiplexer 3 Base Station 4 Subordinate Device

Claims (1)

A plurality of base stations that communicate with a mobile terminal station via a time-division-multiplexed wireless line, a state controller of these base stations, and a line control device having a call processing control function of each terminal station; A base in a system provided between the line control device and the plurality of base stations and including a multiplexing device that multiplexes / separates communication signals and supplies synchronization signals to the line control device and the base station. A station abnormality detection and recovery method,
The line control device sequentially sends periodic monitoring requests to all terminal stations registered in one of the communication areas of the plurality of base stations at every preset monitoring cycle. A periodic monitoring response from the terminal station to the periodic monitoring request via the base station is controlled to transmit, and the periodic monitoring response from the terminal station is set during a threshold time set larger than the monitoring cycle. A base station abnormality detection and recovery method characterized in that if there is a base station that has not relayed any of the base stations, the base station is determined to be abnormal, and the base station is reset by the line control device.

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