JPH07336758A - Mobile communication system - Google Patents

Abstract

PURPOSE:To give warning to an interference wave generating source and to reduce interference by using an idle channel from a speech channel when a base station receives a interference radio wave so as to escape from the effect of the interference wave. CONSTITUTION:A speech signal sent from a regular mobile equipment 1 is detected and an identification signal is added to a frequency signal at the outside of a voice signal band, and then a base station 2 identifies a talking opposite party. A signal without addition of the identification signal is recognized to be a interference radio wave. When an illegal station 9 makes transmission through the same channel, the speech is disturbed. Then the base station 2 receives a radio wave from the illegal station 9. When the station 2 detects that the radio wave is a level of a prescribed level or higher and no identification signal is provided, the station 2 informs it to a controller 8 of an exchange 3. The controller 8 retrieves an idle channel and connects the idle channel and a terminal equipment 5 with a speech switch 6. Simultaneously the controller 8 connects a talkie equipment 7 to the channel of the illegal station 9 with the switch 6 to send a warning announcement signal to the illegal station 9 for warning.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile communication system, and more particularly to a mobile communication system having a warning function for jamming radio waves.

[0002]

2. Description of the Related Art Conventionally, in a mobile communication system such as a car phone and a mobile phone, there has been a case where an interference wave from an illegal station or the like is received and communication is disturbed. In order to avoid such a situation, when the base station of the mobile communication system receives a signal exceeding a certain level during a call, this is regarded as an interfering wave and the radio communication channel is switched to another idle channel. The way is done. Further, before the operation of the communication system or the base station is started, a broadcast may be performed to warn an illegal station so as not to interfere with the communication system.

[0003]

In the conventional countermeasures against interference waves as described above, for example, in a method of switching channels, the person who causes the interference does not notice that it is causing the interference to the communication system. There was a problem in that it may continue to emit jamming radio waves. Also, the use of a device that broadcasts a warning or interrupts the communication of a disturber to forcibly give a warning is limited to before the operation of the system is started. There was a problem of giving. An object of the present invention is to provide a mobile communication system which solves the above-mentioned problems of the prior art and can give a warning to an interfering wave generation source even after the operation of the system is started.

[0004]

According to the present invention, in a communication system including a base station and an exchange, an interfering radio wave detecting means for detecting an interfering radio wave and a wireless call channel during a call are used as other channels in the communication system. It is characterized in that it is provided with a switching means for switching to, and a signal transmitting means for transmitting a warning signal to a radio channel in which an interfering radio wave is detected.

[0005]

According to the present invention, with the above-mentioned configuration, even after the system starts operating, when the jamming radio wave is received, the communication channel is moved to another channel and the radio channel detecting the jamming radio wave is warned. Since the signal is transmitted, the call can be escaped from the influence of the interference wave, and at the same time, the source of the interference wave can be warned.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example in which the present invention is applied to a mobile telephone system will be described in detail below with reference to the drawings. FIG. 1 is a block diagram showing a public mobile telephone network to which the present invention is applied. The mobile phone 1 wirelessly communicates with the base station 2 within the area (dotted line) of the base station 2. The base station 2 is accommodated in the exchange 3, and the exchange 3 accommodates not only a plurality of base stations 2 but also other exchanges in the network or a relay line to another communication network 4. Reference numeral 5 denotes a terminal accommodated in another communication network 4.

2 to 4 are block diagrams sequentially showing the operation at the time of receiving an interfering wave in the mobile telephone network to which the present invention is applied. In FIG. 2, the base station 2 includes transceivers for a plurality of wireless communication channels, and this transceiver also includes signal strength detecting means and interfering radio wave detecting means. FIG. 6 is a diagram showing a power spectrum of a signal obtained by detecting a call signal transmitted from the authorized mobile device 1. As shown in the figure, the signal obtained by detecting the call signal transmitted from the authorized mobile device 1 has an identification signal added to a frequency outside the voice signal band. This identification signal has, for example, seven types of identifiable patterns, and is originally used by the base station to identify the other party with whom it is currently communicating. The transceiver recognizes the signal to which the identification signal is not added as an interfering radio wave.

The base station 2 and the speech path switch 6 of the exchange 3 are connected by a plurality of lines corresponding to radio speech channels. In the figure, for simplification, only two lines for channel 1 (CH1) and channel 2 (CH2) are shown. The base station 2 has a data line connected to the control device 8 of the exchange 3 in addition to the call line, and information such as an interfering radio wave reception notification or a channel switching instruction is transmitted and received by this data line.

The exchange 3 has a speech path switch 6 for accommodating a line from the base station 2 or a relay circuit from another exchange, a talkie switch 7 accommodated in the speech path switch 6 for generating a warning announcement signal, and a speech path. A control device 8 for controlling the entire exchange 3 such as a switch 6 and a talkie device 7 is provided. It is also assumed that the terminal 5 and the line corresponding to CH1 are connected by the call path switch 6, and the mobile device 1 is using the call channel 1 and is in a call with the terminal 5 via the base station 2.

Here, if the illegal station 9 transmits radio waves on the same channel (frequency), the call is disturbed. Generally, in a mobile telephone network, different channels (frequency) are used for an up channel from a mobile station to a base station and a down channel from a base station to a mobile station. In this example, channels 1 and 2 are up channels. pointing. When the base station 2 receives the radio wave from the illegal station 9 and detects that the level of the radio wave is equal to or higher than a predetermined value and that the identification signal is not added, the control of the exchange 3 is performed via the data line. The device 8 is notified of the reception of jamming radio waves.

In FIG. 3, the control device 8 which has received the notification.
Refers to the memory that stores the usage status of each channel and searches for an empty channel. (CH2 is assumed to be vacant.) Then, an instruction to switch the channel is sent to the base station 2, and the speech path switch 6 is controlled to connect the terminal 5 and the CH2 line.
The base station 2 transmits an instruction to switch the channel from 1 to 2 to the mobile device 1, and controls the activation and the like of the CH2 transceiver. Further, the transmitter corresponding to the channel 1 is controlled to transmit at the CH1 frequency instead of the original transmission frequency (≠ CH1). By such processing, the communication channel between the mobile device 1 and the base station 2 is instantly switched from 1 to 2 with almost no influence on the communication.

In FIG. 4, the control device 8 controls the communication path switch 6 to connect the line of CH1 and the talkie device 7, and sends a warning announcement signal from the talkie device to CH1.
Send to. Usually, a transceiver such as an illegal station has the same transmission frequency and reception frequency, so that the warning announcement sent by CH1 is received by the illegal station. The talkie may be stopped after being transmitted for a predetermined time, or may be monitored after monitoring the channel after transmitting for a predetermined time and stopped only when an illegal radio wave is not detected within the predetermined time.

FIG. 5 is a flow chart showing the processing of the channel in communication between the base station 2 and the exchange 3.
FIG. 5A shows the processing of the base station 9. In step S1, it is determined whether or not an interference radio wave is received, for example, by the presence or absence of an identification signal. If the result is negative, step S1 is performed. Although it is repeatedly executed, if the result is affirmative, the process proceeds to step S2. In step S2, it is determined whether or not the signal strength is at or above a level that interferes with communication. If the result is negative, the process returns to step S1, but if the result is affirmative, the process proceeds to step S3. In step S3, the base station 2 transmits a channel switching request to the exchange 3. Up to this point corresponds to FIG. In step S4, the process waits until the channel switching instruction is received from the exchange 3, and in step S5, the channel switching instruction is sent to the mobile device 1 and the operation of the corresponding transceiver in the base station is controlled.

FIG. 5B is a flowchart showing the processing of the exchange 3. In step S10, the process waits until a channel switching request from the base station is received, and in step S11, the currently available communication channel is checked. Search for. In step S12, step S11
A channel switching instruction is transmitted to the base station 2 in order to switch to the empty channel selected in. Step S1
In 3, the line connected to the partner terminal is switched to the line corresponding to the channel to be switched. Up to this point corresponds to FIG. In step S14, the talkie device is connected to the line corresponding to the original channel from which the jamming radio wave was received, and a warning announcement is sent out. This is Figure 4
Corresponding to.

Although the embodiments have been described above, the present invention may be modified as follows. The method of detecting an interfering radio wave is not limited to the presence or absence of the identification signal, and for example, a signal having a reception level of a predetermined value or more may be recognized as an interfering radio wave.
The warning signal may be an announcement such as "stop transmitting radio waves because it is illegal", or may be a simple noise signal. The stronger the warning signal transmission level is, the more effective the warning is, but there is a possibility that the area of another base station is affected. Therefore, when a warning signal is sent from a certain base station, even in the surrounding area, if the channel is switched so that it is switched when it is in use, it is strong without affecting other communication. A warning signal can be sent.

In the embodiment, the case has been described in which an interfering radio wave is mixed in the upstream channel during a call. However, since it is not necessary to switch the channel when the channel is not in use, a talkie is simply connected to the channel. Only need be. Moreover, if a receiver for monitoring is provided, it is possible to monitor when the downlink channel is also free. Further, if the mobile device side is provided with a function of detecting the jamming radio wave of the downlink channel and a function of notifying the base station of the detection result or the channel switching request, it is possible to monitor during the call and switch the channel.

[0017]

The present invention has the following structure.
Even after the operation of the system is started, if a base station or the like receives an interfering radio wave, the call channel is moved to another empty channel and a warning signal such as a talkie is sent to the wireless channel in which the interfering radio wave is detected. As a result, the call can be escaped from the influence of the interference wave, and at the same time, the source of the interference wave can be warned. Therefore, it is possible to make a person who unknowingly emits a jamming wave recognize that the jamming is being given to the communication system, and there is an effect that the jamming is reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing a public mobile telephone network to which the present invention is applied.

FIG. 2 is a block diagram 1 showing in sequence an operation at the time of receiving an interfering wave in a mobile telephone network to which the present invention is applied.

FIG. 3 is a block diagram 2 showing in sequence the operation at the time of receiving an interfering wave in the mobile telephone network to which the present invention is applied.

FIG. 4 is a block diagram 3 showing in sequence the operation at the time of receiving an interfering wave in the mobile telephone network to which the present invention is applied.

FIG. 5 is a flowchart showing processing of the base station 2 and the exchange 3.

FIG. 6 is a diagram showing a power spectrum of a signal obtained by detecting a call signal transmitted from an authorized mobile terminal.

[Explanation of symbols]

1 ... Mobile phone, 2 ... Base station, 3 ... Switch, 4 ... Other communication network, 5 ... Terminal, 6 ... Call path switch, 7 ... Talkie,
8 ... Control device, 9 ... Interfering wave transmission source

Claims (3)

[Claims] 1. A communication system including a base station and an exchange connected to the base station, wherein an interfering radio wave detecting means for detecting an interfering radio wave and a radio communication channel during a call are switched to another channel in the communication system. A mobile communication system comprising switching means and signal sending means for sending a warning signal to a radio channel in which an interfering radio wave is detected. 2. The interfering radio wave detecting means is included in a base station, and is a means for detecting that an interfering radio wave of a predetermined level or higher is received in a radio channel, and the switching means is a radio terminal in the base station. Channel switching instructing means, wireless channel switching means in the base station,
The exchange includes a means for changing the connection of a line corresponding to a radio channel, the signal transmitting means is accommodated in a speech path switch of the exchange, a talkie device for generating a warning announcement signal, and a talkie device for receiving a jamming radio wave. The mobile communication system according to claim 1, further comprising means for connecting to a line corresponding to. 3. The interfering radio wave detecting means determines whether or not the interfering radio wave is present based on the presence or absence of an identification signal present in a signal transmitted from a legitimate wireless terminal. The mobile communication system according to any one of 1.