JP2002095034A - Mobile terminal communication system, radio base station, exchange station and mobile terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To replay a saturated state of a channel allocated to an area. SOLUTION: A mobile terminal communication system contains a radio base station for connecting a mobile terminal and an exchange station for connecting the radio base station. (A) The radio base station detects a signal relating to a reception level intensity of each mobile terminal, and when it is determined that a direct communication can be made by the exchange station, the same radio channel is allocated; but when it is determined that the direct communication cannot be made, the radio channels differing from each other are allocated. (B) The exchange station determines whether the direct communication is possible, and controls the direct communication. (C) when the direct communication can be made by controlling of the exchange station, the mobile terminal makes the direct communication with one radio channel relative to the other mobile terminals.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile terminal communication system including a radio base station connected to a mobile terminal via a radio channel, and an exchange connected to the radio base station via a communication line. The present invention relates to a base station, an exchange, and a mobile terminal, and more particularly, to a mobile terminal communication system, a radio base station, an exchange, and a mobile terminal that can reduce a saturation state of a channel allocated in an area.

[0002]

2. Description of the Related Art In a conventional mobile terminal communication system, a call is realized by allocating one different channel to each mobile terminal when making or receiving a call.

[0003]

This is not an exception even for a call between two mobile terminals located in a position where they can directly communicate with each other wirelessly in the same area. Therefore, near the meeting area where many people gather, as many as 100,000 subscribers gather in the same area, and two subscribers trying to find each other among the crowds with two mobile terminals 2
Since two channels are used at the same time, the channel allocated in the area temporarily becomes saturated, and a situation in which a new call cannot be accepted frequently occurs.

A drastic measure is to increase the number of channels by some method, but there is a limit to this.

An object of the present invention is to provide a mobile terminal communication system, a radio base station, a switching center, and a mobile terminal that can reduce the saturation state of a channel allocated in an area.

[0006]

According to a first aspect of the present invention, there is provided a wireless base station connected to a mobile terminal via a wireless channel, and an exchange connected to the wireless base station via a communication line. In a mobile terminal communication system including
(A) detecting means for detecting a signal related to the reception level strength transmitted from each mobile terminal when at least two mobile terminals are in the same area during a call or during a call; Channel allocating means for allocating the same wireless channel when it is determined that direct communication is possible by the monitoring means of the exchange, and allocating different wireless channels to each other when it is determined that direct communication is not possible by the monitoring means of the exchange. (B) monitoring means for judging and monitoring whether direct communication is possible by receiving a signal relating to the reception level strength detected by the detection means of the radio base station, and When it is determined by the monitoring means that direct communication is possible, the mobile terminals are caused to directly communicate with each other on one wireless channel, and Direct communication control means for controlling the direct communication to be canceled when it is determined by the monitoring means that direct communication is not possible; and (C) the mobile terminal is provided with a direct communication control means for the exchange via the radio base station. And direct communication means for directly communicating with another mobile terminal via one wireless channel when the mobile terminal is in a position where it can directly communicate wirelessly.

In the mobile terminal communication system, the switching center transmits a communication signal on a communication line between the switching station and the radio base station when the monitoring unit determines that the communication can be performed directly. It is preferable to have a communication line control means for controlling the transmission of a communication signal on the communication line when the monitoring means determines that direct communication is not possible.

In the mobile terminal communication system, it is preferable that the signal relating to the reception level strength is intermittently transmitted from the mobile terminal.

According to a second aspect of the present invention, in a radio base station connected to a mobile terminal via a radio channel and to a switching center via a communication line, at least two mobile terminals are connected when calling. Or detecting means for detecting a signal relating to the reception level intensity transmitted from each mobile terminal when in the same area during a call, and the same radio channel when it is determined that direct communication can be performed by the monitoring means of the exchange. And channel assigning means for assigning different radio channels to each other when it is determined that direct communication cannot be performed by the monitoring means of the exchange,
It is characterized by having.

[0010] In a third aspect of the present invention, in a switching station connected via a speech line to a radio base station connected to a mobile terminal via a radio channel, a reception signal detected by a detection means of the radio base station is provided. Monitoring means for judging and monitoring whether direct communication is possible by receiving a signal related to the level strength, and direct communication with each other over one radio channel between the mobile terminals when the monitoring means determines that direct communication is possible. And direct communication control means for controlling via the radio base station such that the direct communication is canceled when the monitoring means determines that the direct communication cannot be performed.

In the switching center, when the monitoring means determines that direct communication can be performed, transmission of a communication signal on a communication line between the switching station and the radio base station is canceled, and It is preferable to have a communication line control means for controlling transmission of a communication signal on the communication line when it is determined that communication cannot be performed directly.

According to a fourth aspect of the present invention, in a mobile terminal connected via a radio channel to a radio base station connected to a switching center via a communication line, the mobile terminal directly connected to the switching center via the radio base station. It is characterized by having direct communication means which is controlled by the communication control means and directly communicates with another mobile terminal via one wireless channel when it is at a position where it can directly communicate wirelessly.

[0013] In the mobile terminal, it is preferable that the signal related to the reception level strength is intermittently transmitted from the mobile terminal.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION In a mobile terminal communication system including a radio base station connected to a mobile terminal via a radio channel and an exchange connected to the radio base station via a communication line, A wireless base station for detecting a signal relating to a reception level intensity transmitted from each mobile terminal when at least two mobile terminals are in the same area during a call or during a call; Channel allocating means for allocating the same wireless channel when it is determined that direct communication is possible by the monitoring means, and allocating different wireless channels to each other when it is determined that direct communication is not possible by the monitoring means of the exchange. ,
(B) the switching center receives a signal related to the reception level intensity detected by the detection unit of the radio base station, determines whether or not direct communication is possible, and monitors the direct communication; and the direct communication is performed by the monitoring unit. Direct communication control means for allowing the mobile terminals to directly communicate with each other on one wireless channel when it is determined that the communication is possible, and for canceling the direct communication when the monitoring means determines that direct communication is not possible And (C) the mobile terminal is controlled by the direct communication control means of the exchange, and directly communicates with another mobile terminal via one wireless channel when in a position where it can directly communicate wirelessly. By having the communication means, it is possible to reduce the number of wireless channels used in the wireless base station.

[0015]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram schematically showing a configuration of a mobile terminal communication system according to one embodiment of the present invention. This mobile terminal communication system includes a mobile terminal communication switching center 10, a radio base station 20, and mobile terminals 30 and 40.

The mobile terminal communication switching station 10
0, 80, a direct communication control unit 11, a communication line control unit 12, and a monitoring unit 13.
And The call line 70 is a line used for the mobile terminal 30, and the call line 80 is a line used for the mobile terminal 40.
This is the line used for Direct communication control means 11
When the monitoring means 13 determines that the mobile terminals 30, 40 can directly communicate with each other, the mobile terminals 30, 4
Control is performed via the wireless base station so as to directly communicate with each other on one wireless channel during the interval 0 and to cancel direct communication when the monitoring means 13 determines that direct communication is not possible. The telephone line control means 12
When the monitoring means 13 determines that the mobile terminals 30 and 40 can directly communicate with each other, the mobile terminal exchange 1
0 and the wireless base station 20 to cancel the transmission of the communication signal in the communication lines 70 and 80, and when the monitoring means 13 determines that direct communication is not possible, the communication line 7
At 0 and 80, control is performed to transmit a call signal.
The monitoring unit 13 determines whether or not direct communication is possible by receiving a signal related to the reception level strength detected by the detection unit 22 of the wireless base station 20 and monitors. In addition, even when the transmission of the communication signal is canceled in the communication lines 70 and 80, the transmission of the control signal and the signal relating to the reception level strength are performed between the mobile terminal communication switching center 10 and the radio base station 20, The mobile switching center 10 monitors the radio channel.

The radio base station 20 includes a channel allocating unit 21
And a detecting unit 22 for performing communication with the mobile terminals 30 and 40 via normal wireless channels 50 and 60 (uplink wireless channel / downlink wireless channel).
Here, the uplink radio channel is a radio channel in the direction from the mobile terminal to the base station. The downlink radio channel is a radio channel in a direction from a base station to a mobile terminal. The channel assignment means 21
When the monitoring means 13 determines that the mobile terminals 30 and 40 can communicate directly with each other, the same radio channel is allocated, and when the monitoring means 24 determines that direct communication is not possible, different radio channels are allocated to each other. The detecting means 22 detects a signal relating to the reception level strength transmitted from each of the mobile terminals 30, 40 when the mobile terminals 30, 40 are in the same area during a call or during a call. The reception level strength is determined for each mobile terminal 30 that has received the pilot signal transmitted from the radio base station 20,
40, each mobile terminal 30,
A signal related to the reception level intensity is transmitted from the wireless base station 40 at regular intervals, and is received and detected by the wireless base station 20. Whether or not direct communication is possible is determined by detecting a signal relating to the respective reception level strength transmitted from each of the mobile terminals 30 and 40, and determining whether or not the value is a predetermined value.

The mobile terminals 30 and 40 communicate with the direct communication means 3
1 and 41, and communicates with the radio base station 20 on both normal radio channels 50 and 60 (uplink radio channel / downlink radio channel). Direct communication means 3
1, 41 are controlled by the direct communication control means 11 of the mobile terminal communication switching station 10 via the radio base station 20 and have one wireless communication with another mobile terminal when they are in a position where they can directly communicate wirelessly. Communicate directly on the channel. The mobile terminals 30 and 40 receive the pilot signal transmitted from the radio base station 20, detect the reception level strength, and transmit a signal related to the reception level strength to the radio base station 20 at regular intervals.

Next, the operation of this embodiment will be described with reference to the drawings. FIG. 2 is a schematic diagram showing an indirect communication state of the mobile terminal communication system according to one embodiment of the present invention. FIG. 3 is a schematic diagram illustrating a direct communication state of the mobile terminal communication system according to one embodiment of the present invention.

Referring to FIG. 2, mobile terminal 30 and mobile terminal 40 are communicating with each other at one radio base station, and mobile terminal 30 and mobile terminal 40 are not in a position where they can directly communicate by radio. This is the case where the mobile terminal 40 is in the state (indirect connection state; indirect communication area 90) (the mobile terminal 40 is not in the direct communication area 100 of the mobile terminal 30). The mobile terminal 30 communicates with the radio base station 2 via the radio channel 50.
0 and bidirectional normal communication are performed. Radio base station 20
Sets up a telephone line 70 for the mobile terminal 30 with the mobile terminal switching center 10. On the other hand, the mobile terminal 40
The two-way normal communication with the wireless base station 20 is performed by the wireless channel 60. The radio base station 20 is a mobile terminal 4
For 0, the communication line 80 is set up between the mobile terminal and the mobile switching center 10. The mobile terminal communication switching center 10
0 and the communication line 80 of the mobile terminal 40 are connected. This enables a call between the mobile terminal 30 and the mobile terminal 40.

Referring to FIG. 3, if the mobile terminal 40 enters the direct communication area 100 of the mobile terminal 30 from the situation of FIG. The mobile terminal communication base station 10 determines that direct communication is possible by receiving a signal related to the reception level strength of each mobile terminal 30 and 40 from the wireless base station 20, and the mobile terminals 30 and 40 and the It controls the base station 20. With this control, the mobile terminal 40
The radio channel 50 used by the mobile terminal 30
By allocating the wireless channel 60 (the wireless channel 60 may be used), the state shifts to a state in which one wireless channel 50 directly communicates with each other wirelessly. The mobile terminal 40 has the radio channel 5
It is possible to directly receive the communication from the mobile terminal 30 through the 0 uplink radio channel. Also, the mobile terminal 40
Can directly transmit a communication to the mobile terminal 30 via the downlink radio channel of the radio channel 50. The radio base station 20 can receive from the mobile terminal 30 and transmit to the mobile terminal 40 using the uplink radio channel of the radio channel 50. Further, the wireless base station 20 can transmit to the mobile terminal 30 and receive from the mobile terminal 40 using the downlink channel of the wireless channel 50.

In the situation shown in FIG. 3, since the communication between the mobile terminal 30 and the mobile terminal 40 is directly performed using the radio channel 50, the communication line between the radio base station 20 and the mobile terminal communication exchange 10 in FIG. 70 / communication between the mobile terminal 30 and the mobile terminal 40 becomes possible without transmitting a communication signal on the communication line 80, so that the transmission of the communication signal on the communication lines 70 and 80 is released under the control of the mobile terminal communication exchange 10. Is done. Even when the transmission of the communication signal is canceled in the communication lines 70 and 80, the control signal and the signal relating to the reception level strength are transmitted between the mobile terminal communication switching center 10 and the radio base station 20. The mobile switching center 10 is monitoring the wireless channel.

In the situation of FIG. 3, the mobile terminal 30
When the mobile terminal 40 and the mobile terminal 40 are out of the range in which they can directly communicate with each other wirelessly (from the situation shown in FIG. 3 to FIG. 2), the mobile terminal communication base station 10 It is determined that direct communication cannot be performed by receiving a signal related to the reception level strength, and the mobile terminals 30 and 40 and the radio base station 20 are controlled so as to cancel the direct communication. By this control, a new radio channel 60 is assigned to the mobile terminal 40 (may be different from the original radio channel), and the radio base station 20 and the mobile terminal communication switching station 10
It is possible to shift to a normal call state (indirect communication state) by transmitting a call signal on the call line 70 / call line 80 between the two.

[0024]

According to the present invention, in a call between two mobile terminals located in a position where they can directly communicate with each other by radio in the same area, a call is normally realized using two channels. In some situations, a call can be realized on one channel, so the channels allocated in the area temporarily become saturated and the situation where new calls cannot be accepted is increased. Can be alleviated.

Further, when the mobile terminals are out of the range where they can directly communicate with each other by radio, a new radio channel is allocated to the mobile terminals under the control of the exchange, so that it is possible to shift to a normal communication state. It is.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically showing a configuration of a mobile terminal communication system according to one embodiment of the present invention.

FIG. 2 is a schematic diagram showing an indirect communication state of the mobile terminal communication system according to one embodiment of the present invention.

FIG. 3 is a schematic diagram showing a direct communication state of the mobile terminal communication system according to one embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 mobile terminal communication switching station 11 direct communication control means 12 call signal control means 13 monitoring means 20 wireless base station 21 channel assignment means 22 detection means 30, 40 mobile terminal 31, 41 direct communication means 50, 60 wireless channel 70, 80 call Line 90 Indirect communication area 100 Direct communication area

Claims (8)

[Claims] 1. A mobile terminal communication system comprising: a radio base station connected to a mobile terminal via a radio channel; and an exchange connected to the radio base station via a communication line.
(A) detecting means for detecting a signal related to the reception level intensity transmitted from each mobile terminal when at least two mobile terminals are in the same area during a call or during a call; Channel allocating means for allocating the same wireless channel when it is determined that direct communication is possible by the monitoring means of the exchange, and allocating different wireless channels to each other when it is determined that direct communication is not possible by the monitoring means of the exchange. (B) a monitoring unit that determines whether or not direct communication is possible by receiving a signal related to a reception level strength detected by a detection unit of the wireless base station, and monitors the switching station; When it is determined by the monitoring means that direct communication is possible, the mobile terminals are allowed to directly communicate with each other on one wireless channel, Direct communication control means for controlling the direct communication to be canceled when the monitoring means determines that direct communication cannot be performed; and (C) the mobile terminal performs direct communication control of the exchange via the radio base station. A mobile terminal communication system comprising direct communication means for receiving control of the means and for directly communicating with another mobile terminal via one wireless channel when the mobile terminal is at a position where direct wireless communication is possible. 2. The switching center releases the transmission of a communication signal on a communication line between the switching center and the radio base station when the monitoring means determines that the communication can be performed directly. 2. The mobile terminal communication system according to claim 1, further comprising a call signal control means for controlling a call signal to be transmitted on said call line when it is determined that direct communication is not possible. 3. The mobile terminal communication system according to claim 1, wherein the signal relating to the reception level strength is intermittently transmitted from the mobile terminal. 4. A wireless base station connected to a mobile terminal via a wireless channel and connected to an exchange via a speech line, wherein at least two mobile terminals are in the same area during a call or during a call. Detecting means for detecting a signal related to the reception level intensity transmitted from each mobile terminal at a certain time, and allocating the same radio channel when it is determined that direct communication can be performed by the monitoring means of the exchange, and And a channel allocating unit that allocates different wireless channels to each other when the monitoring unit determines that direct communication cannot be performed. 5. A switching station connected via a communication line to a radio base station connected to a mobile terminal via a radio channel, receives a signal related to a reception level strength detected by a detection means of the radio base station. Monitoring means for judging and monitoring whether direct communication is possible by the communication means, and when the monitoring means determines that direct communication is possible, the mobile terminals directly communicate with each other on one wireless channel, and the monitoring means A direct communication control means for controlling the direct communication to be canceled when it is determined that the direct communication cannot be performed. 6. When the monitoring means determines that direct communication can be performed, the transmission of a communication signal in a communication line between the exchange and the radio base station is canceled, and the direct communication cannot be performed by the monitoring means. 6. A communication signal control means for controlling transmission of a communication signal on the communication line when the judgment is made.
The listed exchange. 7. A mobile terminal connected via a radio channel to a radio base station connected to an exchange via a communication line, wherein the mobile terminal is controlled by the direct communication control means of the exchange via the radio base station. A mobile terminal having direct communication means for directly communicating with another mobile terminal via one wireless channel when the mobile terminal is at a position where direct wireless communication is possible. 8. The mobile terminal according to claim 7, wherein the signal relating to the reception level strength is intermittently transmitted from the mobile terminal.