JPH0761034B2 - Re-access instruction control method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a re-access instruction control system, and more particularly to a re-access instruction control system in a cellular automobile telephone system in which an omnidirectional antenna and a directional antenna are arranged in a radio base station.

2. Description of the Related Art Conventionally, this type of cellular automobile telephone system has a configuration as shown in FIG. In FIG. 3, a radio base station 1 including a radio 11 to which an omnidirectional antenna 3 is connected, a radio 12 to which a directional antenna 4 is connected, and a control unit 13, and the radio base station 1 The cellular car telephone system is constituted by the exchange 2 connected by the control line 5.

The range for servicing a mobile device (not shown) is a circular range 6 that can be served by the omnidirectional antenna 3 as shown in FIG. The directional antenna 4 has a higher gain than the omnidirectional antenna 3, and the circular range 6 served by the radio base station 1
It is directed to a low electric field area 7 such as a low position or a shadow of a building in which a high-quality telephone call is guaranteed in this area.

When trying to access the wireless base station 1, the mobile device tunes to the channel of the wireless base station 1 having the highest reception level and emits a radio wave. The problem here is that the position of the mobile unit is weak in that the mobile unit should access the radio base station 1 on which of the channel of the omnidirectional antenna 3 and the channel of the directional antenna 4. If it is outside the electric field area 7 and in the area 8 to which the directional antenna 4 is directed, the radio wave from the directional antenna 4 is higher than the radio wave from the omnidirectional antenna 3 in the mobile device. The mobile terminal tunes to the channel of the directional antenna 4 to access the radio base station 1. If there are many such mobile units, the channel of the directional antenna 4 will be occupied, and there will be no channels allocated to mobile units that actually attempt to access the radio base station 1 in the weak electric field area 7.

In order to solve this problem, the reception level of the mobile unit that has accessed the channel of the directional antenna 4 is set to the radio unit 12
At the control line 5 through the control unit 13
Is sent to the exchange 2 which is connected by, and it is determined in the exchange 2 whether the mobile station is in the weak electric field area 7 or in the other area 8. When it is determined that the mobile unit is in the weak electric field area 7, the mobile unit is made to use the channel of the directional antenna 4, and when it is determined that the mobile unit is in the other area 8, the omnidirectional antenna 3 is set to the mobile unit. The exchange 2 gives an instruction to the control unit 13 of the wireless base station 1 through the control line 5 so that the channel is retuned and the wireless base station 1 is accessed again.

This instruction is transmitted on the channel of the directional antenna 4 that the mobile station is accessing, and the mobile station receiving this instruction retunes to the channel of the omnidirectional antenna 3 and accesses the radio base station 1 again. cure.

In such a conventional re-access instruction control system, the exchange 2 determines which of the channel of the omnidirectional antenna 3 and the channel of the directional antenna 4 is to be used by the mobile device. When there are a large number of mobile stations, the load on the exchange 2 is reduced, and the processing capacity of the exchange 2 is reduced.

SUMMARY OF THE INVENTION The present invention has been made to eliminate the above-mentioned conventional drawbacks, and provides a re-access instruction control system capable of preventing a decrease in the processing capacity of an exchange without burdening the exchange. With the goal.

The re-access instruction control method according to the present invention is a re-instruction method for a car telephone system in which a mobile station and a radio base station are accessed using one of the omnidirectional antenna channel and the directional antenna channel. An access instruction control system, and a judging means for judging whether or not the reception level of the radio wave from the mobile device received through the channel of the directional antenna in the radio base station is equal to or more than a predetermined value. And a means for instructing the mobile device to re-access the radio base station by using the channel of the omnidirectional antenna when the judgment means judges that the predetermined value or more.

Embodiment Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, one embodiment of the present invention comprises a radio device 11 to which an omnidirectional antenna 3 is connected, a radio device 12 to which a directional antenna 4 is connected, a control unit 13, and a judgment unit 14. The wireless base station 1 and the exchange 2 connected to the wireless base station 1 by the control line 5.

FIG. 2 is a flow chart of an embodiment of the present invention. The operation of the embodiment of the present invention will be described with reference to FIG. 1 and FIG.

The wireless base station 1 has a wireless device 11 to which an omnidirectional antenna 3 is connected to access a mobile device, a fixed position where radio waves from the omnidirectional antenna 3 do not sufficiently reach, a shadow of a building, etc. A radio 12 to which a directional antenna 4 for servicing the weak electric field area 7 is connected is arranged.
In the radio base station 1 in which these two types of radios 11 and 12 are arranged, a plurality of channels are assigned to the two types of radios 11 and 12, respectively.

One control channel is set for each of the plurality of channels assigned to the wireless devices 11 and 12, and the other channels are call channels used for a call. The radio base station 1 always sends out information about itself through these control channels. Therefore, the wireless base station 1 in which the wireless device 11 and the wireless device 12 are arranged sends out information about itself by the control channel of the wireless device 11 and the control channel of the wireless device 12.

The mobile device is a radio device of several radio base stations 1 at the time of initial setting.
The radio wave reception levels of the control channels 11 and 12 respectively measure, tune to the control channel of the radio base station 1 capable of receiving at the strongest level, enter the standby state, and receive information regarding the radio base station 1. When a call is made to the mobile device in this standby state or when the mobile device attempts to make a call, the radio base station 1 is accessed on this control channel, and the radio base station 1 allocates a call channel for a call. To be

In a mobile device in an area where the directional antenna 4 is not facing, the radio wave of the control channel of the radio device 11 is received at a higher level than the radio wave of the control channel of the radio device 12, so the mobile device is Tune to control channel. In the area where the directional antenna 4 is facing, the mobile device in the weak electric field area 7 is naturally tuned to the control channel of the wireless device 12. In addition, mobile stations in other areas 8 outside the weak electric field area can be tuned to the control channel of the wireless device 12 because the radio wave of the control channel of the wireless device 12 can be received at a higher level than the radio wave of the control channel of the wireless device 11. To do.

However, the control channel of the wireless device 12 is originally for providing services to mobile devices in a very limited area such as the weak electric field region 7, and the wireless base station 1 is accessed by the control channel of the wireless device 12. The number of call channels that can be assigned to a mobile station that has been set is slightly smaller than the number of call channels that can be assigned to a mobile station that has accessed the wireless base station 1 by the control channel of the wireless device 11. .

When a mobile unit tuned to the control channel of the wireless device 12 makes a call, the wireless base station 1 first receives a radio wave from the mobile device on the control channel of the wireless device 12 (step 2
1) The reception level is measured in the wireless device 12 (step 22). The measured result is reported to the judgment unit 14. Utilizing that the reception level of the radio wave from the mobile device in the weak electric field area 7 is lower than the reception level of the radio wave from the mobile device in the other area 8 outside the weak electric field area, the determination unit 14 determines that the mobile device is A reference value for determining whether it is in the weak electric field area 7 or in another area 8 outside the weak electric field area is set in advance.

If the measurement result of the reception level of the radio wave from the mobile device reported from the wireless device 12 is lower than the reference value of the determination unit 14, it is determined that the mobile device is in the weak electric field area 7 (step 23) and the operation is continued. The control channel of the radio 12 is used, and the call channel of the radio 12 is assigned to the mobile device (step 2
Four).

If the reception level measurement result is higher than the reference value, it is determined that there is a mobile device in another area 8 outside the weak electric field area (step 2).
3). In this case, the determination unit 14 instructs the mobile device to stop the access on the control channel of the wireless device 12 by the control channel of the wireless device 12 and to access the wireless base station 1 again on the control channel of the wireless device 11. Is transmitted (step 25). The mobile device receiving this instruction tunes back to the control channel of the wireless device 11 and accesses the wireless base station 1 again.

As described above, in the cellular car telephone system in which the omnidirectional antenna 3 and the directional antenna 4 are arranged in the radio base station 1, the judgment unit 14 is provided in the radio base station 1 so that the channel of the omnidirectional antenna 3 is set in the mobile device. By making a decision as to which channel of the directional antenna 4 is to be used, the radio base station 1 is automatically operated without relying on the exchange 2 connected to the radio base station 1 by the control unit 13 and the control line 5. This determination can be made, and the processing capacity of the exchange 2 can be prevented from decreasing without imposing a burden on the exchange 2.

As described above, according to the present invention, when the radio base station determines that the reception level of the radio wave from the mobile device is equal to or higher than the predetermined reference value, the omnidirectional antenna is provided for the mobile device. By instructing to perform re-access to the wireless base station on this channel, there is an effect that it is possible to prevent a decrease in the processing capability of the exchange without burdening the exchange.

[Brief description of drawings]

1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a flowchart of an embodiment of the present invention, FIG. 3 is a block diagram showing a conventional example, and FIG. 4 is an omnidirectional antenna and directivity. It is a figure which shows the service range with respect to the mobile device with an antenna. Description of symbols of main parts 1 ... Radio base station 3 ... Omnidirectional antenna 4 ... Directional antenna 11, 12 ... Radio 14 ... Judgment unit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshio Otsu 5-33-1 Shiba, Minato-ku, Tokyo Inside NEC Corporation (72) Akihiro Nakamura 3-20-4 Nishishinbashi, Minato-ku, Tokyo Within Nippon Electric Engineering Co., Ltd. (56) Reference Japanese Patent Laid-Open No. 56-156032 (JP, A) Actually developed 60-32850 (JP, U)

Claims (1)

[Claims] 1. A re-access instruction control system of a car telephone system for accessing a mobile station and a radio base station using one channel of a channel of an omnidirectional antenna and a channel of a directional antenna, Determination means for determining whether or not the reception level of the radio wave from the mobile device received through the channel of the directional antenna in the radio base station is equal to or more than a predetermined value, and the determination means has a predetermined value or more. And a means for instructing the mobile device to re-access the radio base station by using the channel of the omnidirectional antenna.