JPS60229538A - Radio communication system - Google Patents

Abstract

PURPOSE:To allow a base station to find its mobile station in an early stage by sending a radio wave from a fault mobile device in a continuous transmission state together with its identification number. CONSTITUTION:The logical circuit of the mobile station is so constituted that a transmitter 5 is turned off when a call signal TXOFF and an answer signal is inputted to a TX together with the identification number of the mobile station. The call signal TXOFF sent out of a base station is received by all mobile devices. Normal mobile devices turn off their TXs normally as shown by a broken line 2 and sends an answer signal to a transmitter 5 as shown by a solid line 3. The transmission electric power of the transmitter 5, however, is cut off, so no radio wave is sent. Then, a faulty mobile device in which the TX can not be turned on and off transmits a modulated ratio wave with said answer signal. When the answer signal is received, the identification number of a mobile device is added to the signal at the base station, which then finds immediately the mobile device disturbing the system.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention consists of a large number of terminal stations and a small number of central stations, and is used to connect a plurality of wireless channel groups used for calls and data transmission. The present invention relates to a wireless communication system having one or more control wireless channels used for connection control to specify to the terminal station which of the communication channels to use when data transmission is required.

(Prior Art) In a wireless communication system using multiple access, one or a small number of upper stations are accessed from a plurality of lower stations. Furthermore, from the viewpoint of effective frequency utilization, many lower stations use the same frequency.

FIG. 2 is a diagram showing an example of the above wireless communication system, and is an example in which one upper station 9 is provided for a plurality of lower stations aa, ab, and ac.

FIG. 8 further takes the car telephone system as an example, and shows its procedure and control method. Mobile stations have the ability to switch to any frequency specified by the base station.
It is always on standby on an unspecified control channel. A control channel is commonly assigned to a certain number of mobile devices.

As soon as a paging signal containing a mobile station number is received via the control channel, the mobile station in question returns a response signal, and then
A channel designation signal containing a channel number for a call is sent from the base station. The mobile station is switched to a communication channel by this channel designation signal, and thereby becomes able to communicate with the base station. FIG. 8 shows the time relationship between the calling signal and the response signal at this time, and shows that the same channel (frequency) is used by a large number of mobile stations in a time-division manner.

Generally, in a wireless communication system that performs multiple access, a common control channel is used to perform a connection operation.

In the example in Figure 2, the response signals are used in a time-division manner, but if they are sent from multiple mobile stations at the same time, there is a sufficient difference in the carrier reception levels at the base station. Sometimes only strong radio waves are accepted. If they are of the same degree, both can be accepted correctly. Therefore, in such a system, when a mobile station becomes unable to control transmission power and fails in a state of continuous transmission, many other mobile stations become unable to connect.

(Objective of the Invention) An object of the present invention is to provide a wireless communication system that can prevent communication service from deteriorating by early discovering a mobile station that has failed in a continuous transmission state.

(Structure of the Invention) In order to achieve the above object, the wireless communication system according to the present invention is composed of a large number of terminal stations and a small number of central stations, and has a plurality of radio channel groups used for communication or data transmission, and nine calls. In a wireless communication system having one or more control radio channels used for connection control that specifies to the terminal station which of the communication channels to use when a need arises for data transmission, the centralized station a detection circuit for detecting that radio waves have continuously arrived at the control channel for a predetermined period of time or more; A circuit is provided that broadcasts a signal requesting a response including an identification number, and when the terminal station receives the broadcast signal, it sends a control signal to turn off the transmission power to its own transmitter, and A logic circuit for sending out a response signal including a number is provided, and when a failure occurs in one of the terminals causing a continuous transmission state, the identification number of the failed terminal station is sent to the central station. .

According to the above configuration, the centralized station can immediately know which terminal station has caused a failure in the continuous transmission state, and the object of the present invention is completely achieved.

(Example) Hereinafter, the present invention will be described in more detail with reference to the drawings and the like.

FIG. 1 shows an embodiment of a mobile station (terminal station) for implementing the wireless communication system according to the present invention. The mobile station consists of a logic circuit 1, a receiver 4, a transmitter 5, a DUP 6, and an antenna T.

When the logic circuit 1 receives the TXOFF call signal, it is configured to turn off the transmitter for control purposes and input a response signal to which its own identification number is added to the Tx. On the other hand, the base station (
The central station) is a common control channel and is equipped with a detection circuit that detects continuous reception. Also, when the detection circuit receives a signal indicating that nine consecutive signals have been detected, T
It also includes a circuit that sends out an XOFF call signal. The TXOFF paging signal sent from the base station is received by all mobile devices. A normal mobile device performs normal TX OFF control as indicated by the broken line 2, and sends a response signal from the logic circuit 1 to the transmitter 5 as indicated by the solid line 3. However, since the transmission power of the transmitter 5 is turned off, no radio waves are emitted. T×・0
A malfunctioning mobile device whose N10FF control is no longer effective will emit radio waves that are not modulated by this response signal. When the base station receives this response signal, the mobile device's identification number is added to the signal, so the mobile device causing interference to the system can be immediately discovered.

Furthermore, after receiving this response signal, the channel designation signal is immediately processed by the base station and the mobile device according to the normal paging sequence, thereby making it possible to contact the user of the malfunctioning mobile device.

(Effects of the Invention) As described above in detail, according to the present invention, a mobile device that has failed in a continuous transmission state transmits radio waves with the descending number of the mobile device, so that the base station This has the advantage that it is possible to know which mobile station has caused a failure, and to take appropriate measures immediately.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an embodiment of a wireless communication system according to the present invention, FIG. 2 is a diagram for explaining a wireless communication system that performs multiple access, and FIG. 8 is a circuit diagram showing an embodiment of a wireless communication system according to the present invention. FIG. 4, which is a diagram for explaining the communication procedure, is a diagram showing the time relationship between the calling signal and the response signal. 1φ・Reference logic circuit 2・--TX on/off 3・・・Response signal 4・・φ receiver 5・・φ transmitter T・9 fist antenna Patent applicant NEC Corporation Representative Patent attorney Inoro Figures 1 and 2 of the series; Figures 3 and 4;

Claims (1)

[Claims] It consists of a large number of terminal stations and a small number of central stations, and has a plurality of wireless channel groups used for voice calls and data transmission, and which of the communication channels is used when a voice call or data transmission is necessary. In a wireless communication system having one or more control radio channels used for connection control, radio waves continuously arrive at the control channel for a certain period of time or more at the central station. a detection circuit for detecting the above, and a circuit for broadcasting a signal to the terminal station requesting a response including the identification number of the terminal with the wireless transmission power turned off using the detection output of the detection circuit; The terminal station is equipped with a logic circuit that, when receiving the broadcast signal, sends a control signal to turn off the transmission power to its own transmitter, and also sends a response signal including an identification number. 1. A wireless communication system characterized in that, when a failure occurs that causes a continuous transmission state, an identification number of the failed terminal station is sent to the centralized station.