JPH05103368A - Method for detecting fault of mobile radio communication system - Google Patents

Abstract

PURPOSE:To automatically and quickly detect the fault of a mobile radio communication system when no answer signal is obtained from a base radio station in response to a test signal by transmitting a fault occurring signal and collectively detecting the fault. CONSTITUTION:Signals received by means of a receiving section 24 are supplied to an electric field detecting section 25 by which the level of the received electric field is detected. A comparator 27 compares the detected level of the received electric field with a reference level and outputs a comparison signal to an abnormality detector 28 when the detected level is lower than the reference level. When the output time to the detector 28 becomes longer than the set periods of a timer 1, 29, a transmission commanding signal is given to a signal transmitting section 23 and a test signal is transmitted to a base radio station. Then the answer signal from the base radio station is monitored and, when no answer signal is obtained, it is discriminated that a fault occurs in the transmitting system of the system and a fault occurring signal is transmitted to a line controller. Therefore, the fault of the system can be collectively detected automatically and quickly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a failure detection method for a dedicated control channel in a mobile radio communication system.

[0002]

2. Description of the Related Art In recent years, a communication system called a multi-channel access system has been widely adopted as a mobile radio communication system for mobile stations represented by a car telephone. In this system, in addition to a plurality of communication channels (S-ch), there is a dedicated control channel (C-ch) for controlling outgoing / incoming connection of a mobile station which is a terminal station.

FIG. 3 shows a system configuration diagram of a conventional mobile radio communication system. In FIG. 3, reference numeral 1 is a mobile station represented by a car phone, and 2 is a mobile station 1 in a formed wireless zone.
It is a wireless base station that wirelessly communicates with. Within this wireless zone, there are a plurality of mobile stations capable of communicating on a plurality of wireless channels (not shown). Reference numeral 3 is a line control device for accommodating by connecting the wireless base station 2 by a wired line, 4 is a circuit switching device for a mobile station which is accommodating for connecting the line control device 3 by a wired line, and 5 is a circuit switching by a subscriber line. A telephone exchange station accommodating the device 4 and a general subscriber telephone 6 accommodated in the telephone exchange station 5 by a subscriber line.

The outgoing / incoming call connection control of the mobile station 1 will be described with reference to FIG. Normally, in the standby state, the mobile station 1 matches the reception channel with the transmission frequency of the dedicated control channel, and waits for an incoming signal for itself in synchronization with the notification signal transmitted from the radio base station 2. When the mobile station 1 makes a call, the operator goes off-hook to perform a call operation, and a call signal is transmitted to the radio base station 2 for a certain period of time through the base station reception channel of the dedicated control channel. This outgoing signal is transmitted to the line control device 3, decoded, and transmitted to the line switching device 4.

When the circuit switching device 4 receives the decoded outgoing signal, the vacant radio channel is designated as the designated communication channel of the mobile station 1 and the channel designating device 3 includes the channel designating signal in the response signal. And to the mobile station 1 via the radio base station 2. The mobile station 1 switches the radio channel to the designated communication channel according to the received channel designation signal, and after the transmission and reception of a signal such as a loop check on the designated communication channel, the communication operation becomes possible.

As described above, in the mobile communication system in which a call is constructed by using many call channels, connection control is performed by a dedicated control channel, so that the connection control time is shortened and the radio frequency is efficiently operated. ing.

[0007]

However, in the above-mentioned conventional system, the dedicated control channel is fixedly used, and therefore the equipment such as the radio base station 2, the line control device 3 and the line switching device 4 should be installed. When a failure occurs, a mobile station located in the wireless zone of the wireless base station 2 cannot make or receive a call and thus cannot function as a mobile wireless communication system.

Therefore, when a failure occurs in each device, it is necessary to quickly detect the failure and notify the operator of the mobile station and the system of an alarm. Therefore, as a failure detection method, the failure is detected by constantly monitoring the transmission output of the wireless base station 2. However, in this method, since only the transmission system of the radio base station is monitored, there is a problem that when a failure occurs in the reception system, the failure can be detected only by the notification from the user of the mobile station.

As a countermeasure against this, a fixed test station is installed in the radio base station 2, and a test is automatically performed at a constant cycle of several minutes to several hours so as not to hinder the outgoing and incoming calls of each mobile station. A method is known in which a signal is sent to the wireless base station 2 to detect a failure.

However, in the method of installing a test fixed station in the radio base station 2 to detect a failure, if the cycle of generating the test signal for failure detection is lengthened, the discovery of the failure will be delayed, On the contrary, if this cycle is shortened, the probability of collision with the transmission signal of each mobile station located in the wireless zone becomes high, which causes new problems such as interference of communication and increase of recording of traffic data. ..

The present invention solves the above-mentioned problems of the prior art by automatically, promptly, and comprehensively fixing a system failure related to a dedicated control channel without affecting the operation of incoming and outgoing calls of each mobile station. An object is to provide a failure detection method for detecting.

[0012]

In order to achieve the above-mentioned object, the present invention is capable of performing incoming / outgoing call control similarly to a mobile station, and can also perform outgoing / incoming calls for testing. The test fixed station has means for detecting the electric field strength of the radio wave transmitted from the radio base station, and means for demodulating a notification signal from the radio base station and monitoring the contents thereof.

[0013]

By the above means, when the electric field strength from the radio base station is reduced or cut off for a certain period of time or continuously for a certain period of time, the notification signal does not include the channel designation signal for incoming and outgoing calls, When it becomes continuous, a test signal is issued to automatically and promptly detect the transmission / reception operation of the wireless base station, the operation of the line control device, the operation of the circuit switching device, and the failure of the connection line between each device. Moreover, it can be done comprehensively.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the fault detecting method according to the present invention will be described below with reference to FIGS. FIG. 1 is a block diagram of a mobile communication system using a failure detection method according to the present invention. In this figure, the radio base station 2 is provided with a duplexer 2a, a dedicated control channel transmitter 2b, and a dedicated control channel receiver 2c, as well as a fixed test station 2d as a test means for carrying out the failure detection method according to the present invention. ing.
2e and 2f are antennas of the duplexer 2a and the test fixed station, respectively. Further, 7 is an operation monitoring device for monitoring the operation of the entire system, and the line control device 3 and the line switching device 4 have the same configuration as in FIG.

FIG. 2 is an internal block diagram of the fixed test station 2d. In FIG. 2, reference numeral 21 is a duplexer for switching between transmission and reception, 22 is a transmission section for transmitting a test signal, 23 is a signal transmission section for generating a test signal and supplying it to the transmission section 22, and 24 is a dedicated control channel of the radio base station 2. Is a receiving unit for receiving. Reference numeral 25 is an electric field detection unit that detects the electric field strength of the dedicated control channel obtained from the reception unit 24, and 26 is a signal decoding unit that decodes the notification signal of the dedicated control channel obtained from the reception unit 24 and detects the presence or absence of a channel designation signal. , 27 are comparators for comparing the level of the electric field received from the electric field detector 25 with a reference level. Further, 28 is an abnormality detector that transmits a failure occurrence signal to the line control device 3 when a system failure is detected, and generates a transmission command signal to be given to the signal transmission unit 23, and is composed of a microprocessor or the like. There is. Reference numerals 29 and 30 are setting means such as a timer for setting the times of the first and second cycles, respectively, and issuing a timer interrupt to the abnormality detector 28.

Next, the operation of the configuration shown in FIG. 2 will be described. The fixed station 2d for test always receives the radio wave coming from the dedicated control channel transmitter 2b of the radio base station 3 via the duplexer 21 and the antenna 2e at the receiver 24 via the antenna 2f and the duplexer 21. There is. This received signal is supplied to the electric field detector 25, and the received electric field level is detected. The detected reception electric field level is compared with the reference level in the comparator 27, and when the reception electric field level is higher than the reference level, the comparison signal of "0" is abnormally detected, and when it is below the reference level, the comparison signal of "1" is abnormally detected. Output to the container 28. When the duration of the comparison signal of “1” from the comparator 27 is longer than the first cycle set by the timer 1, the abnormality detector gives the signal transmission unit 23 a transmission command signal. A test signal is transmitted to the radio base station 2 by this transmission command signal. After that, the presence or absence of a response signal from the radio base station is monitored, and when the response signal is not obtained, it is determined that a failure has occurred in the transmission system of the system, and a failure occurrence signal is transmitted to the line control device 3.

The received signal from the receiving section 24 is also supplied to the signal decoding section 26 to be decoded and a decoded signal is generated. When the wireless base station 2 controls the connection normally, a call signal from the mobile station is received and a response signal is issued, so that a change such as a channel designation signal being included in the decoded signal occurs. Become. On the other hand, if normal connection control is not performed, even if there is a failure only in the receiving system of the system, the decoded signal will be a series of simple indicator signals (unmodulated carrier waves) and will not change. Signal decoding unit 26
Then, the presence or absence of this channel designation signal is detected, and a "0" signal is output to the anomaly detector 28 when the channel designation signal exists, and a "1" signal when it does not exist. In the abnormality detector 28, when the duration of the signal “1” is longer than the second cycle set by the timer 2, the signal transmitter 2
3 gives a transmission command signal to monitor the presence or absence of a response signal from the wireless base station, and when no response signal is obtained, it is determined that a failure has occurred in the receiving system and / or the transmitting system of the system,
A fault occurrence signal is transmitted to the line control device 3.

[0018]

As is apparent from the above embodiment, the present invention is as follows.
Without affecting the outgoing / incoming call connection control of each mobile station,
There is an excellent effect that system failure related to the dedicated control channel can be automatically and promptly and comprehensively detected.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a mobile radio communication system using a failure detection method according to the present invention.

FIG. 2 is a block diagram of a test fixed station in FIG.

FIG. 3 is a block diagram of a conventional mobile radio communication system.

[Explanation of symbols]

 1 Mobile Station 2 Radio Base Stations 2a, 21 Duplexer 2b Dedicated Control Channel Transmitter 2c Speech Channel Receiver 2d Test Fixed Station 2e, 2f Antenna 3 Line Controller 4 Line Switch 5 Telephone Switch 6 Fixed Station 7 Operation Monitoring Device 22 Transmitter 23 Signal transmitter 24 Receiver 25 Electric field detector 26 Signal decoder 27 Comparator 28 Abnormality detector 29, 30 Timer

Claims (3)

[Claims] 1. A radio base station that wirelessly communicates with a mobile station in a radio zone, a line control device that accommodates the radio base station, and a line switching device that accommodates the line control device and performs line exchange. A mobile wireless communication system failure detection method comprising: an electric field detection means for detecting a level of a received electric field of a dedicated control channel transmitted from the radio base station; and a predetermined value when the level is equal to or lower than a reference level. Comparison means for generating a comparison signal, signal transmission means for generating a test signal to be transmitted to the radio base station in response to a transmission command signal, and generation of the transmission command signal and transmission of a failure occurrence signal to the line control device The abnormality detection means includes a test means including an abnormality detection means that performs the transmission command signal when the duration of the predetermined comparison signal is longer than a predetermined cycle. It is given to the signal unit, the fault detection method for a mobile radio communication system and transmits the failure occurrence signal when the response signal corresponding to the test signal from the radio base station can not be obtained. 2. A radio base station that wirelessly communicates with a mobile station in a radio zone, a line control device that accommodates the radio base station, and a line switching device that accommodates the line control device and exchanges lines. A method for detecting a failure of a mobile radio communication system comprising: detecting the presence or absence of a channel designation signal indicating the designation of a speech channel to the mobile station by decoding a reception signal of a dedicated control channel transmitted from the radio base station. And a signal decoding means for generating a predetermined signal when there is no channel designation signal,
Test means including signal transmitting means for generating a test signal to be transmitted to the radio base station in response to a transmission command signal, and abnormality detecting means for generating the transmission command signal and transmitting a failure occurrence signal to the line control device. Having, the abnormality detection means, when the duration of the predetermined comparison signal is longer than a predetermined period, gives the transmission command signal to the signal transmission means, the response signal from the radio base station according to the test signal The failure detection method of the mobile radio communication system, wherein the failure occurrence signal is transmitted when the failure is not obtained. 3. A radio base station that wirelessly communicates with a mobile station in a radio zone, a line control device that accommodates the radio base station, and a line switching device that accommodates the line control device and performs line exchange. A mobile radio communication system failure detection method comprising: an electric field detection means for detecting a level of a reception electric field of a dedicated control channel transmitted from the radio base station; and a first when the level is equal to or lower than a reference level. And a reception means of a dedicated control channel transmitted from the radio base station to detect the presence / absence of a channel designation signal indicating the designation of a communication channel to the mobile station, and to detect the channel designation signal. When there is no signal, a signal decoding means for generating a second signal, a signal transmitting means for generating a test signal to be transmitted to the radio base station in response to a transmission instruction signal, and the transmission instruction signal Signal is transmitted to the line control device and a failure detecting signal is transmitted to the line control device, and a setting means for setting the first and second cycles. When the duration of the first or second signal is longer than the first or second period, the transmission command signal is given to the signal transmission means, and a response signal corresponding to the test signal is obtained from the radio base station. A failure detection method in a mobile radio communication system, characterized in that the failure occurrence signal is transmitted when there is not.