JPH0575530A - Traffic distributing system for mobile object communication system - Google Patents

Abstract

PURPOSE:To suppress the calling frequency of a radio base station having high availability and to average the traffic by sending a channel selection re- executing instruction to a down-control channel when the use rate a the message channel is increased at the radio base station. CONSTITUTION:The traffic distributing start threshold value T1 and the traffic distribution stop threshold value T2 are held in a main controller 1 of a radio base station. Then the channel selection re-executing instruction transmitting cycle tau is held in a down-control channel transmitting device 2. The controller 1 calculates and monitors the use rate of the message channel and instructs the device 2 to start transmission of the cycle tau when the calculated use rate is increased more than the value T1. Meanwhile the controller 1 instructs the device 2 to stop transmission of the cycle tau when the use rate of the message channel is reduced less than the value T2. In such a way, the mobile object telephone terminal synchronized with a base station having a large traffic volume is synchronized again with another base station. Thus the calling frequency of the radio base station having high use rate is limited and the traffic volume is average.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traffic distribution system in a mobile communication system.

[0002]

2. Description of the Related Art EIA (ELECTRONIC INDU) which is a specification of a cellular mobile radio communication system.
STRIES ASSOCIATION) IS-3-
D or TACS (TOTAL ACCESS C
OMMUNICATIONS SYSTEM) Issu
In the conventional cellular mobile phone system of the e-4 system, the mobile phone terminal after the power is turned on scans the channel range on a predetermined control channel, measures the carrier reception level of the downlink control channel, and Among them, the downlink control channel received with the strongest received electric field carrier level is selected and tuned. FIG. 3 is a diagram showing an example of each service area of a plurality of radio base stations constituting the cellular mobile telephone system, and FIGS. 4 (A) and 4 (B) are call channels for a call request from a mobile telephone terminal. It is a figure which shows the normal call processing sequence until allocation, and the call processing sequence when there is no idle speech channel.

In FIG. 3, a mobile telephone terminal is located in the service area a of the radio base station 20, and the radio base station 2
After tuning to the downlink control channel broadcast from 0,
Areas b, c, d, e, f, g overlapping with the service areas of the other wireless base stations 21, 22, 23, 24, 25, 26.
Even when the mobile telephone terminal moves to (1), the mobile telephone terminal keeps tuning to the downlink control channel of the radio base station 20 as long as it can receive the downlink control channel signal broadcast from the selected radio base station 20.

When the above-mentioned mobile telephone terminal performs an outgoing call or incoming call answering operation, and if there is an empty call channel in the call channel held by the radio base station 20, it moves as shown in FIG. 4 (A). The body telephone terminal can realize a call service by allocating one free call channel among the call channels held by the wireless base station 20, but when there is no free call channel, as shown in FIG. In addition, the radio base station 20 transmits a Directed Retry signal to the mobile telephone terminal on the downlink control channel, whereby the mobile telephone terminal can tune to the radio base stations 21, 22, 23, other than the radio base station 20. After reselecting and tuning any of the downlink control channels of 24, 25, and 26, the call / call response is retransmitted on the uplink control channel of the reselected radio base station. By doing so, the call channel held by the reselected radio base station is assigned to realize the call service.

[0005]

In FIG. 3, assuming that the traffic volume in the service area a of the radio base station 20 is very large and there is no idle communication channel,
In the conventional method, the mobile telephone terminal selecting the downlink control channel broadcast from the radio base station 20 is connected to the service area of the radio base station 20 and other radio base stations 21, 22 and 22.
Although the downlink control channels of other radio base stations are in a selectable state when they are located in the overlapping areas b, c, d, e, f, g of the service areas of 23, 24, 25, 26. Instead, it means that the radio base station 20 continues to tune to the downlink control channel, and the traffic load is further applied to the radio base station 20 incapable of the call service.

The call connection procedure in the above state is shown in FIG.
As shown in (B), a call is made to the radio base station 20 once, or an incoming call response is transmitted from the mobile telephone terminal to the uplink control channel of the radio base station 20, and thereafter, the call channel is not allocated and the Directed The Retry signal is transmitted to the mobile telephone terminal on the downlink control channel of the radio base station 20, and the mobile telephone terminal receives radio signals from the radio base stations 21, 22, 23, 2 based on the Directed Retry signal.
Re-selecting any of the downlink control channels broadcasted by 4, 25, and 26 and transmitting the re-call / incoming-call response, and then realizing the call by assigning the call channel held by the re-selected radio base station. Therefore, there is a drawback that invalid processing is increased in the radio base station and the mobile telephone switching center, the processing capacity is squeezed, and the call connection time becomes long.

[0007]

A traffic distribution system in a mobile communication system according to the present invention provides a downlink control channel and an uplink control channel for transmitting a control signal between a radio base station and a mobile telephone terminal. A traffic distribution method in a mobile communication system having a pair of control channels and a plurality of communication channels in one wireless base station, wherein the wireless base station is based on the traffic volume and the number of communication channels expected in the local station. The traffic distribution activation threshold value, the traffic distribution stop threshold value, and the channel selection re-execution instruction transmission cycle are determined in advance, and the ratio of the total number of communication channels held and the number of communication channels in use is determined by the communication channel usage rate. When the calculated communication channel usage rate is equal to or higher than the traffic distribution activation threshold, It is transmitted to the talking terminal on the downlink control channel with periodicity based on the threshold of the channel selection re-execution instruction transmission cycle, and then the speech channel usage rate decreases and falls below the traffic distribution stop threshold. The transmission of the channel selection re-execution instruction transmission cycle on the downlink control channel is stopped when the time becomes.

The radio base station has a main controller that holds the traffic distribution activation threshold and the traffic distribution stop threshold, and a downlink channel transmitter that holds the channel selection re-performance instruction transmission cycle. The main control unit always calculates the call channel usage rate of its own station, and when the calculated call channel usage rate is equal to or higher than the traffic distributed activation threshold value The downlink control is carried out on the downlink control channel with periodicity based on the threshold value of the transmission cycle of the channel selection re-execution instruction, and thereafter when the traffic channel usage rate falls below the traffic distribution stop threshold value. It is characterized in that the transmission of the channel selection re-performance instruction transmission cycle on the channel is stopped.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. 1 is a diagram showing a relationship between a communication channel usage rate of a radio base station and a channel selection re-performance instruction transmission according to an embodiment of the present invention, and FIG. 2 is a diagram showing an application example of the present invention.
2A is a block diagram of a mobile communication system, FIG.
FIG. 3 is a block diagram of the wireless base station in FIG.

In FIG. 2A, a call between mobile telephone terminals or between a mobile telephone terminal and a general wired telephone terminal is carried out via the radio base stations 20, 21, 22 and the mobile telephone exchange station 10. .. The mobile telephone exchange station 10 is connected to the radio base stations 20, 21, 22 by combination lines 201, 211, 221, which are signal lines and call lines. The radio base stations 20, 21, 22 are provided respectively for certain service areas 20a, 21a, 22a, and mobile telephone terminals moving in the corresponding service areas and wireless call origination, calling, answering and call relaying. I do. An antenna for that purpose is provided in each of the radio base stations 20, 21, and 22. In the drawing, the wireless base stations 20, 21, 2,
2 is shown as a representative example, other radio base stations (not shown) are installed as areas which are partitioned without gaps and are connected to the mobile telephone switching center 10. The mobile telephone exchange station 10 is connected to a general telephone network 40 by a call line 30.

As shown in FIG. 2B, the radio base station 20 comprises a main controller 1, a downlink control channel transmitter 2, an uplink control channel receiver 3, and a speech channel controller 4. Here, the downlink control channel transmitter 2, the uplink control channel receiver 3, and the speech channel controller 4 are illustrated one by one, but a plurality of devices may be installed depending on the scale of the radio base station. The mobile telephone switching center 10 is connected to the call channel control device 4 by a call line 201s. The downlink control channel transmitter 2, the uplink control channel receiver 3, and the speech channel controller 4 are multi-connected to the main controller 1 by a signal line 100.
The mobile telephone switching center 10 is connected to the mobile telephone switching center 10 by a signal line 201c. Antennas 2a, 3a and 4a are connected to the downlink control channel transmitter 2, the uplink control channel receiver 3, and the speech channel controller 4, respectively.

Next, the EIA and TA configured as described above
A traffic distribution method in the CS specification mobile communication system will be described.

In each radio base station, the traffic distribution start threshold T1, the traffic distribution stop threshold T2, and the channel selection re-execution instruction shown in FIG. 1 are calculated from the traffic volume and the number of communication channels expected in each radio base station. The transmission cycle τ is determined in advance, and the traffic distribution activation threshold T
1 and the traffic distribution stop threshold T2 are held in the main controller 1 in each radio base station shown in FIG. 2B, and the downlink control channel transmitter 2 is made to hold the channel selection re-performance instruction transmission cycle τ. In each radio base station, the main controller 1 constantly calculates and monitors the call channel usage rate of its own station, and controls the mobile phone terminal when the call channel usage rate is equal to or higher than the traffic distributed activation threshold T1. Rescan Global Act as a channel selection re-execution instruction
The downlink control channel transmitter 2 is instructed to start the transmission of the ion Overhead Message. On the basis of this transmission start instruction, the downlink control channel transmission device 2 sets Re at the time interval determined by the channel selection re-execution instruction transmission cycle τ.
scanGlobal Action Overhea
d Message is transmitted from the antenna 2a onto the downlink control channel.

Rescan Global Actio
The mobile telephone terminal receiving the n Overhead Message scans the channel range on the predetermined control channel and reselects the control channel.
Overlapping areas b, c, d, e, of the service area shown in
Among the mobile telephone terminals located at f and g, those that reselect the control channel broadcast from another radio base station appear, and the traffic can be dispersed.

As described above, after the traffic distribution is started,
When the traffic volume in the service area a of the radio base station 20 decreases and becomes less than the traffic distribution stop threshold T2 shown in FIG. 1, the downlink control channel transmitter 2 is instructed to stop transmitting the control channel selection re-execution instruction. As a result, the downlink control channel transmitter 2 stops the periodic transmission of the channel selection re-implementation instruction.

[0016]

As described above, according to the present invention, when a communication channel usage rate in one radio base station is increased, a channel selection re-implementation instruction is transmitted on the downlink control channel so that another radio base station can transmit the channel selection re-execution instruction. Since the mobile telephone terminal that can be tuned to the broadcast downlink control channel is tuned to another radio base station, the number of new calls generated in the radio base station with a high call channel usage rate is reduced and the average traffic is reduced. Can be promoted. Also, the wireless base station,
It can be realized with mobile telephone terminals without changing the specifications of EIA and TACS.
Sending cted Retry signal, Directed
Since it is possible to omit the control channel reselection of the mobile telephone terminal receiving the Retry signal, it is possible to reduce the uplink / downlink control channel traffic and the call connection time.

[Brief description of drawings]

FIG. 1 is a diagram showing a relationship between a communication channel usage rate of a wireless base station and channel selection re-performance instruction transmission in an embodiment of the present invention.

2A and 2B are diagrams showing an application example of the present invention, in which FIG. 2A is a block diagram of a mobile communication system, and FIG. 2B is a block diagram of a radio base station in FIG.

FIG. 3 is a diagram showing an example of respective service areas of a plurality of radio base stations configuring a cellular mobile telephone system.

4 (A) and (B) are diagrams showing a normal call processing sequence until a call channel is allocated to a call request from a mobile telephone terminal, and a call processing sequence when there is no idle call channel.

[Explanation of symbols]

 T1 traffic distribution start threshold T2 traffic distribution stop threshold τ channel selection re-execution instruction transmission cycle 1 main controller 2 downlink control channel transmitters 2a, 3a, 4a antenna 3 uplink control channel transmitter 4 speech channel controller 10 Mobile telephone switching center 20, to 26 Radio base station 30, 201s Telephone line 40 General telephone line network 100, 201c Signal line a, 20a, 21a, 22a Service area b Overlap area

Claims (2)

[Claims] 1. A radio base station having a downlink control channel and an uplink control channel for transmitting a control signal between a mobile telephone terminal as a pair of control channels, and one radio base station having a plurality of communication channels. In the traffic distribution method in a mobile communication system having the following, the radio base station determines a traffic distribution start threshold value, a traffic distribution stop threshold value, and a channel selection re-establishment threshold from the traffic volume and the number of communication channels expected in the local station. The fulfillment instruction transmission cycle is determined in advance, the ratio of the total number of call channels held and the number of call channels in use is calculated as a call channel usage rate, and the calculated call channel usage rate activates the traffic distribution activation. When the threshold value is exceeded, the channel selection re-performance instruction transmission cycle is transmitted to the mobile telephone terminal on the downlink control channel. Transmission with a periodicity based on the threshold of the transmission period, and then when the traffic channel usage rate drops below the traffic distribution stop threshold value, the channel selection re-execution instruction transmission cycle on the downlink control channel is transmitted. A traffic distribution method in a mobile communication system characterized by stopping traffic. 2. The radio base station includes a main control device that holds the traffic distribution activation threshold and the traffic distribution stop threshold, and a downlink channel transmission device that holds the channel selection re-performance instruction transmission cycle. , The main controller always calculates the call channel usage rate of its own station,
When the calculated call channel usage rate is equal to or higher than the traffic distribution activation threshold value, a cycle based on the threshold value of the channel selection re-performance instruction transmission cycle on the downlink control channel for the mobile telephone terminal And then the transmission of the channel selection re-execution instruction transmission cycle on the downlink control channel is stopped when the speech channel usage rate drops below the traffic distribution stop threshold value. A traffic distribution system in the mobile communication system according to Item 1.