JPH0661923A - Mobile communication system - Google Patents

Abstract

PURPOSE:To provide a mobile communication system which can deal with the large capacity and the high speed movements and also can reduce the deterioration of the speech quality caused by the frequent hand-off states. CONSTITUTION:A 1st radio zone 10 is provided for the talking carried out in a high speed moving state together with the 2nd radio zones 20-1-20-7 which are subdivided from the zone 10 and used for the talking in a stop state or a low speed moving state. A mobile station is provided with a means which decides whether the mobile station itself is moving at a high speed or not. Based on this deciding result, the 1st and 2nd radio zones are selectively used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile communication system for automobiles, mobile phones and the like, and more particularly to a large capacity mobile communication system capable of accommodating a large number of subscribers and making a call at high speed.

[0002]

2. Description of the Related Art In a conventional mobile communication system such as an automobile and a mobile phone, a large number of wireless zones are continuously arranged in order to cover a wide service area and accommodate a large number of subscribers at a limited frequency. When the same channel is repeatedly reused in a wireless zone that is separated by a certain distance or more, and when a mobile station talks while moving across multiple wireless zones, the channel that can be used in the destination wireless zone is used. A cellular system is employed, which has a function of handoff that sequentially selects and switches and continues a call.

[0003]

In such a conventional cellular system, in order to accommodate a large number of subscribers,
It is possible to improve the frequency utilization efficiency by reducing the wireless zone and reusing the same channel, but in this case, the wireless zone becomes smaller, so you can make a call while moving at high speed in a car, etc. In this case, the frequency of moving between wireless zones increases and the possibility of frequent handoffs increases. Therefore, there is a problem that frequent call interruptions occur due to channel switching due to handoffs, resulting in extremely deteriorated call quality.

[0004]

In order to solve the above-mentioned problems, the mobile communication system according to the present invention subdivides the first wireless zone used for a call during high-speed movement and the first wireless zone. A second radio zone used for a call that is stopped or moving at a low speed is provided, and the mobile station is provided with means for judging whether or not the mobile station itself is moving at a high speed. Select and use the wireless zone.

As a means for determining whether or not the mobile station is moving at high speed, it is effective to measure the frequency at which the mobile station moves between radio zones and make a determination based on the magnitude.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a conceptual diagram for explaining a radio zone configuration of a mobile communication system to which the present invention is applied. In the figure, a dashed circle 10 indicates a wireless zone used for a call when moving at high speed, and solid circles 20-1 to 20 indicate a wireless zone used when a mobile station is stopped or moving at a low speed. Although not shown in the figure, the base station that operates is installed in the center of each wireless zone. In addition, F1 in () in the figure
F4 shows an example of the channel arrangement used in each of the wireless zones 20-1 to 20, and is not adjacent to each other.
1 shows that the same channel is repeatedly used in each of the wireless zones −1 and 7, 20-2 and 6, and 20-3 and 5.

The wireless zone configuration as shown in FIG. 1 is repeated,
In a system that is continuously arranged, in a wireless zone configuration such as the solid circles 20-1 to 20 in the figure, accommodate a large number of subscribers because the frequency reuse efficiency is improved as described above. In the wireless zone configuration such as the dashed circle 10, the zone area is larger than the wireless zones 20-1 to 20-7, so that the frequency of handoff due to movement between wireless zones can be reduced.

In the present invention, two types of radio zones as shown in FIG. 1 are arranged in one service area, the mobile station is provided with means for judging whether or not the mobile station itself is moving at high speed, and according to the result of this judgment, By selectively using two types of wireless zones, we are constructing a mobile communication system that has a large capacity and is compatible with high-speed movement.

FIG. 2 is a flow chart showing an embodiment of the present invention, which is an example in which the frequency of moving between wireless zones is used as a means for determining whether or not a mobile station is moving at high speed. In the flowchart, the mobile station that originated the call starts a call through the wireless zone for low speed movement such as 20-1 to 20 in FIG. 1 and sets the wireless zone selection timer Tz when the first handoff occurs. Start. If the next handoff occurs before the timer Tz times out, it is judged that the movement frequency between the wireless zones is high, and the handoff is performed to the wireless zone for high speed movement such as 10 in FIG. This avoids deterioration of call quality.

In the above description, the method of using the handoff occurrence frequency as the means for determining whether or not the mobile station is moving at high speed has been described. However, when the mobile medium of the mobile station is an automobile or the like, information on the speedometer and navigation are provided. It is apparent from the above description that the present invention can be applied even if the system information is input to the mobile station.

[0011]

As described above, the mobile communication system according to the present invention can accommodate a large number of subscribers within the same service area by subdividing the radio zone corresponding to high-speed movement and this radio zone into subdivisions. And a wireless zone for low speed movement are arranged, the mobile station is provided with means for judging whether or not it is moving at high speed, and by using the above two wireless zones selectively according to the judgment result, a large capacity can be obtained. It is possible to realize a system that supports high speed movement.

Furthermore, by using the magnitude of the movement frequency between the radio zones as a means for determining whether or not the mobile station is moving at high speed, it is possible to easily realize a system in which the deterioration of speech quality due to frequent handoffs is small.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing an example of a wireless zone configuration of a mobile communication system.

FIG. 2 is a flowchart showing an example in which the frequency of moving between wireless zones is used as a means for determining whether or not a mobile station is moving at high speed.

[Explanation of symbols]

 10 Wireless zone corresponding to high speed movement 20-1 to 7 Wireless zone corresponding to low speed movement

Claims (2)

[Claims] 1. A service area composed of one or a plurality of wireless zones, and a large number of mobile stations connected within the service area to base stations forming the wireless zones via wireless transmission lines to make a call. In a mobile communication system including: one or more first wireless zones, and a plurality of second wireless zones installed in the first wireless zone, the mobile station is moving at high speed. Determining means for determining whether or not, and if the determining means determines that the vehicle is stopped or moving at a low speed, a call is made through the second wireless zone,
A mobile communication system comprising: means for making a call via the first wireless zone when it is determined that the vehicle is moving at high speed. 2. The mobile communication system according to claim 1, wherein the frequency of movement between wireless zones is used as the determination means for determining whether or not the vehicle is moving at high speed.