JPH08172660A - Mobile equipment calling method in cellular mobile communication system - Google Patents

Abstract

PURPOSE: To relieve processing amount of a mobile communication exchange station and a radio base station and to distribute the traffic attended with a call to a mobile equipment in a cellular mobile communication system. CONSTITUTION: In the case of calling a mobile equipment, a call is made from only a large zone radio base station 5 covering a paging area. Upon the receipt of a call, a mobile equipment 6 selects a radio base station of which reception state is the best among small zone radio base stations 2-4 in the paging area and the large zone radio base station 5 and a call reply to a mobile communication exchange station via the radio base station. Furthermore, the availability of the radio base station is broadcasted toward the mobile equipment 6 based on a radio channel operating state (number of idle channels) of all the radio base stations in the paging area and the mobile equipment 6 selects a radio base station in the best reception state among the available radio base stations.

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 cellular mobile communication system having one or more large zone radio base stations covering a paging area including a plurality of small zone radio base stations. .

[0002]

2. Description of the Related Art In a conventional cellular mobile communication system, a small zone is configured for effective use of frequency, and an area in which a plurality of such small zones are put together is defined as a paging area. The mobile device performs position registration for each paging area, and the position registration is updated when the mobile device moves between paging areas or when the power is turned on.

When calling a mobile station, a call is made from all the radio base stations in the paging area whose location is registered, and the mobile station selects a radio base station having the best radio wave reception state and calls the mobile station. The call has been received and a call response has been transmitted to the mobile switching center via the radio base station.

Simultaneously calling from all the radio base stations in the paging area increases the processing amount of the mobile switching center and the radio base station. In particular, as the zone radius decreases, the number of radio base stations increases. As a countermeasure, a communication system in which a call to a mobile device is performed by a communication satellite line, and a call response from the mobile device and subsequent communication are performed by a terrestrial line has been considered as a countermeasure.

(Literature: Japanese Unexamined Patent Publication No. 4-354216, Izumi Hatakeyama)

[0006]

As described above, in a conventional cellular mobile communication system, when a call to a mobile station is made, a call is made from all the radio base stations in a paging area whose location is registered. The mobile device receives a call from the radio base station having the best radio wave reception state,
A paging response was transmitted to the mobile switching center via the radio base station. However, in this case, since the call is made from all the radio base stations in the paging area, the mobile communication switching center and all the radio base stations in the paging area increase the processing amount associated with the incoming connection of the mobile station, and the Since the process is performed regardless of the use condition of the radio channel of the base station, there is a problem that traffic is biased to a certain radio base station.

Further, in a mobile communication system in which a satellite channel is constituted by a supervising base station, a multi-beam communication satellite and a mobile device, and a ground line is formed by the base station and the mobile device, a mobile satellite is called by a communication satellite. In the case of a communication system in which communication is performed on a line and call response from the mobile device and subsequent communication are performed on a terrestrial line, the mobile device does not have two types of receivers having different frequency bands for a satellite line and a terrestrial line. The capacity of the mobile device itself increases,
There is a problem that the connection time to the mobile device becomes longer due to the call using the communication satellite.

[0008] An object of the present invention is to use a large-zone radio base station to increase the capacity of a mobile station itself and the connection time to the mobile station without increasing the capacity of the mobile station itself as in the method disclosed in the aforementioned literature. By reducing the processing amount associated with the incoming connection of the communication switching center and the small zone radio base station to the mobile device, and selecting the radio base station according to the radio channel usage status of the radio base station and performing a call response Another object of the present invention is to restrict incoming calls from a radio base station having few vacant channels to a mobile device, and to distribute traffic of the radio base station.

[0009]

According to the present invention, there is provided a method for calling a mobile station in a cellular type mobile communication system, wherein a mobile communication switching station calls a mobile station via a large zone radio base station, and the mobile station is a large zone radio base station. From the large zone wireless base station and the small zone wireless base station,
A radio base station that emits a radio wave with the best reception state in the mobile device is selected, and a call response is sent to the mobile switching center via the radio base station.

Further, the mobile telecommunication switching center determines that the small zone wireless base station and the large zone wireless base station can use a wireless base station having a certain idle channel as a usable wireless base station based on the use status of the wireless channels. A radio base station that broadcasts to a mobile device via a radio base station and a large zone radio base station, and the mobile device emits a radio wave with the best reception condition in the mobile device from the available radio base stations. Select.

[0011]

[Operation] A call to a mobile station in the paging area is made only from a large zone base station covering the same area instead of all small zone radio base stations in the same area. From the zone base station and all the small zone radio base stations in the paging area, a radio base station transmitting the best radio wave is selected, and a call response is performed via the selected radio base station. Furthermore, from the above-mentioned channel usage status in all the wireless base stations, whether or not the wireless base station can be used at that time is broadcast, and the mobile device selects the connection destination from the available wireless base stations. Select a wireless base station.

[0012]

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

FIG. 1 is a block diagram showing a configuration of a cellular mobile communication system to which an embodiment of a mobile station paging method according to the present invention is applied, FIG. 2 is a block diagram of a mobile station, and FIG.
And (b) are radio channel usage statuses (number of empty channels) of all radio base stations in the paging area, and
FIGS. 4 and 5 show the arrival of a call to a mobile station corresponding to the situation of the radio base station shown in FIGS. 3 (a) and 3 (b). It is a sequence diagram.

The cellular mobile communication system shown in FIG.
It comprises a mobile communication switching center 1, small zone radio base stations 2, 3, and 4, a large zone radio base station 5 covering the entire paging area, and a mobile device 6. The mobile communication switching center 1 includes a control unit 11 and a selection unit 12 for selecting an available radio base station from the radio channel usage status (the number of free channels) of all the radio base stations in the paging area. And an information adding unit 13 for adding the wireless base station number of the available wireless base station selected in the above to the broadcast information broadcast to the mobile device 6 via the wireless base stations 2, 3, 4, and 5. The mobile device 6 includes a control unit 61 and an extraction memory unit 62 which extracts a wireless base station number from the broadcast information, and updates / holds the number.
And a measuring unit 63 for measuring a reception state of a radio wave emitted from the wireless base station, and a selecting unit 64 for selecting a wireless base station having the best reception state from the measurement result.

An outline of the incoming call sequence shown in FIG. 4 will be described below for the case where the radio base station status diagram is shown in FIG. 3 (a). 4 and 5, a wavy line indicates wireless transmission.

In FIG. 3A, the mobile communication switching center 1
Are wireless base stations 2, 3, 4, 5 usable by the selection unit 12.
The information adding unit 13 adds a wireless base station number unique to the available wireless base stations 2, 3, 4, and 5 to the broadcast information. The wireless base station 5 is a large zone wireless base station. The broadcast information to which the wireless base station number is added is broadcast to the mobile device 6 via each wireless base station.

The mobile unit 6 receives the broadcast information, extracts the radio base station number added to the broadcast information by the extraction memory unit 62, updates it, and holds it. When calling the mobile station 6, the mobile switching center 1 transmits the call to the mobile station 6 via the large zone radio base station 5. The mobile station 6 that has received the call changes the reception state of radio waves transmitted from the small zone wireless base stations 2, 3, and 4 and the large zone wireless base station 5 having the wireless base station number held in the extraction memory unit 62. When the selection unit 64 selects the small-zone wireless base station 2 that has the best radio wave reception state measured by the measuring unit 63 and transmits the call response via the selected small-zone wireless base station 2 to the mobile communication Send to exchange 1. The mobile communication switching center 1 that has received the call response performs a line connection process with the mobile device 6.

Next, as shown in FIG. 3B, the number of vacant channels in the radio base station 2 is one, and the mobile communication switching center 1 restricts incoming calls from the radio base station 2 to the mobile station 6. In this case, as shown in FIG. 5, the radio wave transmitted from the radio base station 2 is excluded from the radio waves to be measured by the mobile device 6 for the received electric field strength, and the call response generated by the mobile device 6 can be used. It is transmitted from the wireless base station 3 among the base stations 3, 4, and 5.

As described above, the available radio base stations are specified from the usage status of the radio channels in all the radio base stations in the paging area, and the radio base station traffic is selected by selecting the radio base station to be used from the radio base stations. The amount can be dispersed.

[0020]

By making a call to the mobile station only from the large-zone radio base station covering the paging area, the capacity of the mobile station itself and the connection time to the mobile station can be increased as in the case of using communication sanitation. This has the effect of reducing the processing amount associated with the incoming connection of the mobile communication switching center and the small zone radio base station to the mobile station, and furthermore, the radio base station according to the use status of the radio channel in each radio base station. By selecting and transmitting a paging response, the effect of restricting incoming calls from a radio base station with few available channels to a mobile device, dispersing the traffic volume of the radio base station, and improving the use efficiency of the radio channel can be obtained. is there.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration example of a cellular mobile communication system provided with a mobile station paging method of the present invention.

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

FIG. 3 is a wireless base station status diagram showing the wireless channel usage status of the wireless base station and whether the wireless base station can be used or not.

FIG. 4 is a diagram showing an example of an incoming sequence of a call to a mobile device in the mobile communication system of FIG.

5 is a diagram showing an example of an incoming sequence of a call to a mobile device in the mobile communication system of FIG.

[Explanation of symbols]

 1 Mobile Communication Switching Office 2, 3, 4 Small Zone Radio Base Station 5 Large Zone Radio Base Station 6 Mobile Station 11 Control Section 12 Selection Section 13 Information Addition Section 61 Control Section 62 Extraction Memory Section 63 Measurement Section 64 Selection Section

Claims (2)

[Claims] 1. A mobile in a cellular mobile communication system having a large number of small zone radio base stations and one or more large zone radio base stations covering a paging area including a plurality of the small zone radio base stations. In a mobile station calling method of calling a mobile station in the paging area from a telecommunication switching station, the mobile telecommunication switching station calls the motive through the large zone radio base station, and the mobile station is called from the large zone radio base station. When receiving the call of, from the large-zone wireless base station and the small-zone wireless base station, select a wireless base station that emits a radio wave with the best reception state in the mobile device, and through the wireless base station And a paging response to the mobile switching center. 2. The mobile communication switching center, as a wireless base station capable of using a wireless base station having a certain idle channel, as a wireless base station capable of using a wireless base station according to the usage status of wireless channels in the small zone wireless base station and the large zone wireless base station. Broadcast to the mobile station via the small zone radio base station and the large zone radio base station, and the mobile station has the best reception state in the mobile station from the available radio base stations. The method of calling a mobile station in a cellular mobile communication system according to claim 1, wherein a radio base station that transmits radio waves is selected.