JP3062981B2 - Mutual monitoring method between base stations - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication network system comprising a plurality of base stations and a large number of mobile stations for mobile communication such as a portable telephone, and to a mutual communication between a plurality of base stations in a service area. It relates to a monitoring method.

[0002]

2. Description of the Related Art A time division multiple access system (hereinafter, TDMA)
The communication is performed by allocating a plurality of channels obtained by cutting out a time axis into a plurality of blocks that are periodically repeated, to each station. In this TDMA system, it is important that the channels on the time axis allocated in each base station are synchronized. If the synchronization is not established, the timing of the transmission signals from each station overlaps, and Efficiency decreases.

Conventionally, since each base station of the communication system is not constantly monitored, when an abnormality occurs, a report from a user or a maintenance manager or a decrease in system utilization due to the abnormality is detected. An abnormal occurrence was discovered. As a test method, a loopback test, etc., in which a signal is passed through the transmitting unit to the receiving unit by the base station alone is performed, but whether or not normal radio wave transmission is actually performed in the air, and whether normal radio wave reception is possible It is difficult to judge whether or not such a phenomenon and the cause of the abnormality have been monitored and tested by connecting a dedicated measuring device for analyzing the cause of the abnormality.

[0004]

However, since there is no conventional monitoring function, the discovery of an abnormality is delayed until the user reports a problem in the normal service. In addition, there is a problem that when a problem such as a decrease in transmission output is difficult for the user to determine, the response is delayed. Further, in order to perform the abnormality monitoring, a special device for performing the monitoring is required, and a radio signal and a communication procedure are required, so that there is a problem that a cost for maintenance work is required.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and eliminates the above-mentioned problems. The purpose is to provide a monitoring method.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a mobile communication using radio in a service area comprising a plurality of base stations connected to a communication network in which a central office for general management is installed. This is a mutual monitoring method between base stations of a service system, wherein the base station transmits and receives radio signals, a control unit 1-1 for controlling transmission and reception, a synchronization device 1-2 for controlling synchronization, as shown in FIG. It comprises a receiving section 1-3, a transmitting section 1-4, and a data communication section 1-5 for communicating with a central station. The central station sequentially designates base stations to be monitored from each other from a plurality of base stations in a service area. Further, a monitoring network is established by giving a reference reception level as a criterion for judging abnormality to each base station and a reference error occurrence rate, and the designated base stations receive radio signals from each other and receive reception levels. Seeking and receiving The error occurrence rate is determined from the data check code (CRC check code). If the error rate is not satisfied, the central station is notified of the occurrence of an abnormality via a communication network. It is characterized by comprehensively judging from the reported abnormality report, estimating and outputting an abnormal base station and its cause.

[0007]

According to the present invention, by adopting the above configuration, the radio signals of the normal service are always received from each other and the judgment is made based on the judgment standard, so that the normal system state can be accurately grasped and monitored. In addition, since the central station comprehensively determines the abnormal base station based on the abnormality report from all the base stations and the cause such as transmission failure or reception failure, it is possible to easily and promptly and accurately determine.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 2 is a diagram showing an overview of the mutual monitoring system of the present invention and a telephone calling procedure. As shown, the system includes a plurality of base stations 25 in a service area 24,
The base stations are connected to a central office 21 and a central office 22 which are managed over a telephone network 20, and a telephone service is provided to a mobile station 28 in a service area 24 by radio. It is a system that performs.

When calling the mobile station 28 from the ordinary telephone 23, when dialing, the exchange 22 makes a call request a to the central office 21. The central station 21 is a base station 25, 26, 27
Call b. The base station 25 in which the mobile station 28 is in its own radio wave area sends a reply c to the central station 21, and the central station 21 notifies the exchange 22 of the base station 25 number d. The exchange 22 is connected to the base station 25, and the ordinary telephone 23 can talk to the mobile station 28.

FIG. 3 is a block diagram showing the configuration of a base station used in the mutual monitoring system of the present invention. As shown in the figure, a base station 1 used in the present system includes a control unit 1-1 comprising a microprocessor or the like, a synchronizing device 1-2 for synchronizing the transmission / reception timing of the own station with transmission / reception of radio waves, transmission for transmitting / receiving radio signals And a data communication unit 1-5 for connecting to a telephone network. The reception antenna 2 receives a signal from another base station and transmits a synchronized transmission signal to the antenna. Send from 3.

The control unit 1-1 is constituted by a microcomputer or the like and analyzes transmission / reception data of the base station of the synchronization partner and controls the synchronization unit 1-2.
This is a device for synchronizing the radio signal transmitted from the own station with the radio signal of the synchronization partner base station received in 3. The receiving unit 1-3 converts the radio wave received by the receiving antenna 2 into reception data at the timing controlled by the synchronizer 1-2, and converts the radio wave into the receiving data.
1 and the transmission unit 1-4 transmits the transmission data from the control unit 1-1.
The signal is converted into a radio wave at the timing controlled by the synchronization device 1-2 and transmitted from the transmission antenna 3. Data communication unit 1
-5 is for receiving a command from the central office through the telephone network. The telephone network connecting the central office and the base stations may use radio waves.

FIG. 4 is a diagram showing communication between a base station and a mobile station using a communication channel. As shown in the figure, in the TDMA system, a channel is time-divided into a transmission frame and a reception frame of 2.5 ms, and each frame is further divided into four slots. The transmitting and receiving frames are synchronized and 1
You can communicate using one slot. In the example of FIG. 3, multiplex communication of four calls is possible with one frequency.

Therefore, it is, of course, necessary to synchronize the transmission and reception frames of the base station and the mobile station. However, as shown in FIG. 2, a plurality of base stations are installed in the same service area and the mobile station has the same frequency. In order to communicate with the base station, it is necessary to synchronize the transmission frame and the reception frame between a plurality of base stations in the service area. For this purpose, each base station has a synchronization device (see FIG. 3) using a control channel to perform synchronization control.

FIG. 5 is a diagram showing transmission timings of control channels between base stations. As shown in the figure, the channels of each base station are synchronized, and an abnormality is monitored by mutually receiving intermittently transmitted control channel signals. The monitoring method will be described below.

The central station designates a base station to be monitored for each base station. It is preferable that the base stations for the mutual monitoring have a master-slave relationship between the synchronized base stations. FIG. 1 is a diagram showing the flow of the arrangement, synchronization and monitoring of base stations in a service area. As shown in the figure, the central station (see FIG. 2) assigns the base stations for mutual monitoring according to the order in which a synchronous relationship has been established with respect to all the base stations from the master base station # 1 to the slave base stations # 3-7. By specifying and notifying each base station, a monitoring network shown by a dotted line in FIG. 1 is established. Further, the central station has a reference error rate (CRC) as a criterion for judging an abnormality to each base station.
Error occurrence rate) and a reference reception level (RSSI low-level slot detection rate).

Each base station receives the radio signal of the other station specified by the central station, obtains the error occurrence rate and reception level of the control channel signal, compares them with the reference given by the central station, and performs better than the reference. If it is abnormal, report it to the central office via the telephone network.

The operation of the system will be described with reference to the model shown in FIG. Slave base station # 2-1 becomes slave base station # 3-
And monitor base station # 2 is determined to be normal, and slave base station # 3-
2 monitors the slave base station # 2-1, determines that there is an abnormality, and reports each to the central station.
Slave base station # 1-1 monitors slave base station # 2-1, and slave base station # 2-1 becomes slave base station #
If the result of monitoring 3-1 is not abnormal, it is determined that there is a high possibility that the reception of the slave base station 3-2 is abnormal. In this way, the central station constantly collects the results of monitoring the normal service status from each base station, makes comprehensive judgments, and can estimate and output the most probable abnormal location and cause.

[0018]

As described above, according to the present invention, the following excellent effects are expected. (1) Normally, the radio signals of the normal service are mutually received and the judgment is made based on the judgment standard, so that the normal system state can be accurately grasped and monitored.

(2) The central station comprehensively determines the abnormal base station and the cause of transmission failure or reception failure based on the abnormality report from all base stations, so that quick and accurate determination can be easily performed. Becomes

(3) Normally, monitoring is performed using radio waves for service, so that no special device is required on the transmitting side, and the cost is reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing the flow of the arrangement, synchronization and monitoring of base stations in a mutual monitoring system of the present invention.

FIG. 2 is a diagram showing an overview of a mutual monitoring system of the present invention and a telephone calling procedure.

FIG. 3 is a block diagram showing a configuration of a base station used in the mutual monitoring system of the present invention.

FIG. 4 is a diagram illustrating communication between a base station and a mobile station using a communication channel.

FIG. 5 is a diagram illustrating transmission timing of a control channel of each base station.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base station 1-1 Control part 1-2 Synchronizer 1-3 Receiving part 1-4 Transmitting part 1-5 Data communication part 2 Receiving antenna 3 Transmitting antenna 20 Telephone network 21 Central station 22 Switching station 23 General telephone 24 Service area 25 Base station 26 Base station 27 Base station 28 Mobile station

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04B 17/00 H04B 7/26

Claims (1)

(57) [Claims] 1. A mutual monitoring system between base stations of a mobile communication system using radio in a service area comprising a plurality of base stations connected to a communication network in which a central station for general management is installed, wherein: The base station has transmission / reception means for transmitting / receiving a radio signal, and communication means for communicating with the central station, and the central station sequentially designates base stations to be monitored from each other from a plurality of base stations in a service area via a communication network. Further, a monitoring network is established by giving each base station a reference reception level as a criterion for judging abnormality and a reference error occurrence rate, and the designated base stations transmit radio signals to each other by the transmission / reception means. Upon receiving, the reception level is obtained, and further, the error occurrence rate is obtained from the received data check code. If the error occurrence rate is not satisfied, the occurrence of an abnormality is notified to the central office via the communication network. Mutual monitoring system between base stations, characterized by comprehensive judgment to estimate the abnormal base station and failure cause output from the reported come anomaly reports from all base stations.