JP2526517B2 - Base station selection type calling method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cellular mobile communication system, and more particularly to a base station selection type calling system in a cellular mobile communication system composed of a mobile switching center and a plurality of base stations.

[0002]

2. Description of the Related Art Conventionally, when a mobile station of a cellular mobile communication system makes a call, it measures the received electric field strength of downlink radio channels from a plurality of adjacent base stations and determines the best received electric field strength among them. I made a call request to my base station.

[0003]

In the conventional calling method, a mobile station measures the received electric field strength of a downlink radio channel from a plurality of adjacent base stations, and the base station having the best received electric field strength among them is measured. Make a call request to the station. This call request is issued by the wireless resource status of the base station (number of free wireless channels).
The traffic volume may be biased toward a certain base station because it is performed regardless of the above. In addition, the traffic volume of the base station is biased, and a call request fails when a call request is made when there is no radio resource state. In order to prevent these, it is necessary to issue a re-calling instruction from the mobile communication switching center, but in this case, the processing amount becomes large, and there is a problem that connection delay occurs and the quality of service deteriorates.

[0004]

According to the base station selection type calling system of the present invention, a mobile station measures the received electric field strengths of downlink radio channels from a plurality of adjacent base stations and the received electric field strengths are measured. A means for selecting two base stations having the second highest received electric field strength from the top by comparison, and information on the received electric field strengths from the selected two base stations are added to the call request, And a means for separately transmitting a call request to two base stations, wherein the mobile communication switching center has a plurality of base stations transmitted from one mobile station via a plurality of base stations within a certain period of time. When a plurality of outgoing call requests are received, the means for extracting the respective received electric field strengths from the outgoing call requests, and the extracted received electric field strengths and the radio resource status of the base station are effective. Means for selecting a suitable base station, In addition, the mobile station is a diversity reception circuit that can be formed into two independent reception circuits by using two synthesizers. After the call request, it is set as two independent reception circuits, and the base station selected by the call request is used. It has means for receiving the call acceptance and means for switching to diversity reception at the received frequency after receiving the call acceptance.

[0005]

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

FIG. 1 is a block diagram showing the configuration of a cellular mobile communication system to which an embodiment of a base station selection type calling system according to the present invention is applied. FIG. 2 is a block diagram of a mobile device.
Is a received electric field strength of a downlink radio channel from each base station used in the embodiment, FIG. 4 is a radio resource state of each base station used in the embodiment, and FIG. 5 is a sequence diagram.

The cellular mobile communication system shown in FIG.
It is composed of a mobile communication switching center 1, base stations 2, 3, 4 and a mobile device 5. For the mobile switching center 1, a control unit 11, an extracting unit 12 for extracting the received electric field strength, a memory unit 13 for holding the radio resource states of all base stations connected to the mobile switching center 1, and a base station are selected. The selection unit 14 is provided. As shown in FIG. 2, the mobile unit 5 compares the received electric field strength with the measuring section 51 for measuring the received electric field strength, and selects the base station having the second highest received electric field strength from the top. A diversity receiving circuit 54 and a control unit 55 are provided, and the diversity receiving circuit 54 includes the receiving units 540, 5
41 and synthesizers 542 and 543.

In the following description of the operation, the sequence diagram of FIG. 5 will also be referred to.

When the mobile unit 5 tries to make a call, the measuring unit 51 measures the received electric field strengths E2, E3 and E4 of the downlink radio channels from the radio stations 2, 3 and 4, as shown in FIG. Assuming that a result is obtained, the comparison / selection unit 52 causes the base stations 2, 4
To the base station 2 or 4 selected by adding the received electric field strengths E2 and E4 to the call origination request (call origination request + reception electric field strength E2 and call origination request + reception electric field strength) separately. Strength E
4) is transmitted. The mobile telecommunication switching center 1 extracts the reception electric field intensities E2 and E4 from the call origination request transmitted from the mobile unit 5 via the base stations 2 and 4 within a fixed time by the extraction unit 12. In addition, the base station 2, which is held in the memory unit 13,
If the wireless resource states of 3 and 4 are as shown in FIG. 4,
The selection unit 14 selects a valid base station 2 from the extracted received electric field strengths E2 and E4 and the radio resource states of the base stations 2, 3 and 4, and receives a call request for a call request via the base station 2 from the mobile station. Send to 5. The mobile unit 5 has a diversity receiving circuit 5
4 synthesizers 542 and 543 are adjusted to the radio channels of the base stations 2 and 4, respectively, and receiving units 540 and 541
To an independent receiving circuit. When the receiving unit 540 receives the call acceptance from the base station 2, the radio channel of the synthesizer 543 of the receiving unit 541 is tuned to the synthesizer 542 of the receiving unit 540, and the receiving units 540 and 541 are switched to the diversity receiving circuit 54 to perform communication. I do.

[0010]

According to the base station selection type calling system of the present invention, in response to a call request from a mobile station, the received electric field strength of the downlink radio channel from the base station and the radio resource state of each base station Since an effective base station is selected, there is an effect that the deviation of traffic volume is prevented and the probability of call failure is reduced, so that the service quality is improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a cellular mobile communication system to which an embodiment of a base station selection type calling system of the present invention is applied.

FIG. 2 is a block diagram of a mobile device.

FIG. 3 is a diagram showing a received electric field strength of a downlink radio channel from each base station used in the embodiment.

FIG. 4 is a diagram showing a radio resource state of each base station used in the embodiment.

FIG. 5 is a sequence diagram used in the embodiment.

[Explanation of symbols]

 1 Mobile Communication Switching Office 2, 3, 4 Base Station 5 Mobile Station 11 Control Section 12 Extraction Section 13 Memory Section 14 Selection Section 51 Measurement Section 52 Comparison Selection Section 53 Transmission Section 54 Diversity Reception Circuit 55 Control Section 540, 541 Reception Section 542 , 543 synthesizer

Claims (1)

(57) [Claims] 1. In a cellular type mobile communication system comprising a mobile switching center and a plurality of base stations, a mobile unit measures a received electric field strength of a downlink radio channel from a plurality of adjacent base stations, Means for comparing the received electric field strengths and selecting two base stations having the second highest received electric field strengths, and a call request for information on the received electric field strengths from the selected two base stations. And a means for separately transmitting a call request to the two base stations, wherein the mobile telecommunication switching center transmits the call from one mobile station to a plurality of base stations within a certain period of time. Waiting for a plurality of outgoing call requests transmitted by receiving the plurality of outgoing call requests, means for extracting respective received electric field strengths from the outgoing call requests, and the extracted received electric field strengths and the base station Effective depending on wireless resource status And a means for selecting a base station, wherein the mobile unit is a diversity receiving circuit that can be made into two independent receiving circuits by using two synthesizers, and after the call request, two independent receiving circuits are provided. Selecting a base station, comprising means for receiving a call acceptance from the base station selected by the call request, and means for switching to diversity reception at the received frequency after receiving the call acceptance. Type calling method.