JPH1169426A - Reconnection channel switching method against interference time - Google Patents

Abstract

PROBLEM TO BE SOLVED: To evade the influence of interference by switching to a channel from a band different from a previous time among using bands divided beforehand in the case that a reconnection request from a mobile station is generated and it is detected that a network side simultaneously receives the interference from another communication system. SOLUTION: The A band base station reception of a present system is divided into three and managed, and at the time of the reconnection request from the mobile station, a base station side monitors a frequency band to which the old using channel of the mobile station belongs and judges whether or not the interference from the other system is received. In the case of judging that the interference from the other system by B band base station transmission is received, a free channel is selected from the other frequency bands 1 and 2 different from the frequency band 3 to which the old using channel of the mobile station belongs, the selected free channel is specified and communication is performed. In the case that no interference from the other system is present, the free channel is searched from the same frequency band to which the old using channel belongs, the channel is specified and the communication is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-interference system for switching a reconnection channel in order to avoid the influence of interference at the mobile station receiving side or base station receiving side during communication in mobile communication. Time reconnection channel switching method.

[0002]

2. Description of the Related Art Conventionally, in mobile communication, when a reconnection channel is switched, an unused communication line is selected.

[0003] Reconnection channel switching has been performed when the channel switching control from the network side does not work well, the communication line is not switched to a high-quality line, and is disconnected due to quality deterioration or the like. .

[0004]

In the case of interference at some radio frequencies, the influence of the interference can be avoided by selecting an unused line when selecting a channel at the time of switching the reconnection channel by the conventional method. it can. However, when simultaneously receiving interference over a wide range of channels from another communication system, even if an unused line is selected at the time of reconnection channel switching, if the frequency is close, the influence of the interference cannot be avoided. .

Further, when the mobile station receives interference on the receiving side, a control signal due to channel switching control on the network side may not be received by the mobile station. No reconnection channel switching is performed.

[0006] The present invention has been made in view of the above,
It is an object of the present invention to provide a method of switching a reconnection channel at the time of interference, which avoids the influence of interference when receiving interference from another communication system during communication.

[0007]

To achieve the above object, according to the present invention, a mobile station receiving side or a base station receiving side receives a wide range of channels from another communication system during communication in mobile communication. When such interferences are simultaneously received, the operating frequency band of the mobile communication system is divided into a plurality of bands and managed, and a reconnection channel switching to a band less affected by interference or another band of the same mobile communication system is performed. The point is to do it.

According to the first aspect of the present invention, it is detected that a reconnection request is issued from a mobile station and that the network side is simultaneously receiving interference from another communication system over a wide range of channels. In such a case, when switching the reconnection channel, an unused line is selected from a band different from the previous band among the used bands divided in advance.

Further, the present invention described in claim 2 is based on claim 1.
In the invention described above, when the mobile station receiving side receives interference from another communication system during communication, the mobile station spontaneously disconnects the communication line and requests reconnection.

According to the second aspect of the present invention, when quality deterioration due to interference is detected during reception by the mobile station during communication, the mobile station voluntarily disconnects the communication line and issues a reconnection request. Do. At this time, it is notified that the line has been disconnected due to the interference of the mobile station side reception, and the network side selects an unused line from a band different from the previous band among the used bands divided in advance.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing an example of division of a used frequency band and a spectrum of a communication signal in another system for explaining a method of switching a reconnection channel upon interference according to an embodiment of the present invention. As shown in the figure, it is assumed that the base station reception band of the own system is A, and the band is managed by dividing the band into (1) to (3). The mobile station transmission band of another system whose use band exists in the vicinity is B, and B
When the spectrum of the mobile station transmission signal in the band leaks into the base station reception in the A band as shown in FIG. 1, (3) the signal-to-noise ratio deteriorates due to the base station reception in the band of the band, and the communication state deteriorates. I do. In such a state, the communication is disconnected, and (3) the line within the band is selected at the time of switching the reconnection channel, the influence of the interference continues. Therefore, a line of band (2) that is not affected by mobile station transmission in band B is selected. If the influence of interference extends to (2) band,
(1) Select a line from a band.

Next, the processing of this embodiment will be described with reference to the sequence shown in FIG. In FIG. 2, at the time of a reconnection request from a mobile station, the base station (network) checks the frequency band to which the old used line of the mobile station belongs, and determines whether or not interference is received from another system (step). S1
1). This determination is made, for example, when interference is detected on a large number of lines in the corresponding frequency band, but may be determined by another method.

If it is determined that interference has been received from another system, an empty line is selected from another frequency band different from the frequency band to which the old used line of the mobile station belongs (step S13). A call is made by designating the selected free line (step S17).

If it is determined in step S11 that there is no interference from another system, a free line is searched for from the same frequency band to which the old used line belongs (step S1).
5) If there is no vacant line, the process proceeds to step S13 to select a vacant line from another frequency band. If there is a vacant line, a call is made by specifying this vacant line (step S17). .

FIG. 3 shows an example of division of a frequency band used in mobile station reception and a spectrum of a communication signal in another system for explaining a method of switching a reconnection channel at the time of interference according to another embodiment of the present invention. FIG. As shown in the figure, it is assumed that the mobile station reception band of the own system is C, and that the band is managed by dividing it into three (1) to (3).
When the base station transmission band of the other system whose use band exists in the vicinity is D, and the spectrum of the base station transmission signal in the D band leaks into the mobile station reception in the C band as shown in FIG.
(3) In a band band, the signal-to-noise ratio is degraded by mobile station reception, and the communication state is degraded. In consideration of the possibility of interference from other systems when the communication quality deteriorates due to interference at the mobile station reception, the mobile device voluntarily disconnects the communication line,
Request reconnection. At this time, it notifies that the communication line has been disconnected due to interference with the previously used line. The net side is
If the previous communication line of the mobile station is the band (3), then the line is selected from the band (2).

Next, the processing of this embodiment will be described with reference to the sequence shown in FIG. In FIG. 4, when the mobile station detects a deterioration in call quality due to downlink interference during a call (steps S21 and S23), the mobile station disconnects the line, confirms that the line has been disconnected, and then disconnects with a reconnection request signal from the mobile station. Is notified to the base station (network) that the factor is downlink interference.

Since the base station (network) cannot determine whether the downlink interference is from another system, it checks whether the cause is downlink interference by a notification from the mobile station (step S25), and disconnects the line. If the cause is downlink interference, an empty line is searched for from another frequency band different from the frequency band to which the old used line of the mobile station belongs (step S2).
7), and make a call by designating this free line (step S)
31).

If it is determined in step S25 that the cause of the line disconnection is not downlink interference, an empty line is searched for from the same frequency band to which the old used line belongs (step S29). S2
Go to 7 and select a free line from another frequency band,
If there is a vacant line, a call is made by designating the vacant line (step S31).

As yet another embodiment, when the frequency band used by the mobile communication system is composed of a plurality of spaced bands, for example, three bands, the band (1) to ( Control can be similarly performed by considering 3) as use frequency bands having respective intervals.

[0021]

As described above, according to the present invention,
In a mobile communication system, a frequency band to be used is divided into a plurality of bands, and when a mobile station receiving side or a base station receiving side simultaneously receives interference over a wide range of channels from another communication system during communication, the divided frequency band is used. Since the reconnection channel is switched from a band to a band less affected by interference or to another band of the same mobile communication system, if other communication systems are simultaneously affected by interference in a wide range of channels within the used band, Also, by performing reconnection channel switching, the influence of interference can be avoided.

Further, according to the present invention, when the mobile station receiving side receives interference from another communication system during communication, the mobile station voluntarily disconnects the communication line and requests reconnection. , The effects of interference can be avoided.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of division of a used frequency band and a spectrum of a communication signal in another system for describing a method of switching a reconnection channel upon interference according to an embodiment of the present invention.

FIG. 2 is a sequence diagram showing the operation of the embodiment of FIG.

FIG. 3 is a diagram illustrating an example of division of a frequency band used in mobile station reception and a spectrum of a communication signal in another system for describing a method of switching a reconnection channel at the time of interference according to another embodiment of the present invention. is there.

FIG. 4 is a sequence diagram illustrating the operation of the embodiment of FIG. 3;

Claims (2)

[Claims] When a mobile station receiving side or a base station receiving side simultaneously receives interference over a wide range of channels from another communication system during communication in mobile communication, the operating frequency band of the mobile communication system is changed to a plurality of frequencies. A reconnection channel switching method for interference, wherein the method is divided into bands and managed, and reconnection channels are switched to a band less affected by interference or another band of the same mobile communication system. 2. If the mobile station receives interference from another communication system during communication, the mobile station voluntarily disconnects the communication line and requests a reconnection. 2. The method for switching a reconnection channel at the time of interference according to 1.