JP2675374B2 - Wireless communication control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a wireless communication system having a plurality of wireless channels for controlling transmission / reception and communication with a wireless terminal station under control of a wireless base station. , A wireless communication control having means for increasing the transmission efficiency of transmission information from the wireless terminal station to the wireless base station and the connection rate of communication between the wireless base station and the wireless terminal station by operating the wireless channel efficiently It is related to the method.

Note that the term “channel” (also referred to as “radio channel”) is used in this specification, and a specific meaning thereof is “frequency” in the case of a frequency division multiple access system and “frequency” in the case of a time division multiple access system. Is a "time slot",
The present invention can be realized with the same configuration in both the frequency division multiple access system and the time division multiple access system.

[Conventional technology]

Conventional Method Part 1. FIG. 7 is a diagram showing the configuration of a normal wireless communication system including a wireless base station and a plurality of wireless terminal stations.

As shown in FIG. 7, in the case of the wireless communication system in which a plurality of wireless terminal stations 2a to 2c exist under the control of the wireless base station 1 in the wireless zone, in addition to the communication channel, calling and receiving of the wireless terminal stations 2a to 2c are performed. There is a method in which at least one incoming control channel and at least one outgoing control channel are set as control channels for control, and the control channels are time-shared and shared by a plurality of wireless terminal stations.

The wireless terminal station that is waiting for an incoming call receives the incoming call control channel of the existing wireless zone. FIG. 8 shows an example of the signal configuration of the incoming call control channel from the wireless base station to the wireless terminal station.

The wireless terminal station receives the incoming call information (P ₁ , P ₂ , P ₃ , ..., P _j ) 3a to 3d.
When the incoming call information to the local station is detected, the incoming call is controlled, the communication channel is designated by the wireless base station, and then the communication is performed on the communication channel.

When a call origination request transmission instruction is given from the wireless terminal station subscriber during the incoming call waiting operation, the wireless terminal station randomly accesses the upstream transmission control channel to the wireless base station and transmits the transmission information.

The uplink transmission control channel is notified to the wireless terminal station in advance by the base station information (B ₁ , ... B _j ) 4a, 4b in the downlink incoming control channel shown in FIG. Access methods for wireless terminal stations include the Aloha method and the Slotted Aloha method.

The wireless terminal station and the wireless base station perform outgoing call control using the outgoing call control channel, and perform communication using the communication channel after the wireless base station specifies the communication channel.

FIG. 9 shows a call origination / termination control flow of the wireless terminal station in the conventional method 1 described above.

In addition, when the wireless terminal station has mobility and it is necessary to register the location wireless zone of the wireless terminal station, the location registration information is used to randomly access the uplink transmission control channel from the wireless terminal station to the wireless base station. And then sent.

Conventional method No. 2. In the above-mentioned conventional method No. 1, a method has been shown in which a common control channel for controlling transmission / reception of a plurality of wireless terminal stations on one channel is dedicatedly provided in addition to the communication channel. There is also a method of individually controlling transmission / reception of one wireless terminal station on one channel.

The wireless terminal station has means for distinguishing an empty channel that is not used for communication, and the wireless terminal station that is waiting for an incoming call cyclically switches the downstream empty channel and receives sequentially. The incoming information to the wireless terminal station is transmitted using one of the downlink free channels. The wireless terminal station has means for distinguishing the channel on which the incoming call information is transmitted. When the incoming call information is transmitted, the circulation of the receiving channel is interrupted and the channel on which the incoming call information is transmitted is received.

When the wireless terminal station receives the incoming call information to itself, the wireless terminal station transmits incoming call response information on the upstream channel corresponding to the channel to perform incoming call control, and performs communication using the channel. When the received incoming call information does not correspond to the own station, the above circulation of the receiving channel is restarted.

The transmission information from the wireless terminal station is transmitted to the wireless base station using an upstream free channel, and transmission control and communication are performed using the channel.

FIG. 10 shows a call originating / receiving control flow of the wireless terminal station in the conventional method 2 described above.

Conventional method No. 3. In addition to the conventional method No. 1 and No. 2 described above, there is also a method combining these.

That is, an incoming call control channel is set as a control channel for controlling the incoming call of the wireless terminal station, common control of the incoming call of a plurality of wireless terminal stations is performed by the incoming call control channel, and the outgoing call is made to one wireless terminal station with one idle communication channel. This is a method of individually controlling outgoing calls.

The wireless terminal station that is waiting for an incoming call receives the downlink incoming call control channel of the existing wireless zone. When the wireless terminal station receives the incoming call information for its own station, it performs incoming call control using the uplink incoming call control channel, and after the wireless base station designates the communication channel, the wireless terminal station communicates with the channel.

The wireless terminal station has means for discriminating an idle communication channel, and transmission information from the wireless terminal station is transmitted to the wireless base station by using the upstream idle communication channel, and transmission control is performed by using the communication channel. Communication is performed on the communication channel.

FIG. 11 shows a call originating / receiving control flow of the wireless terminal station in the conventional method 3 described above.

[Problems to be solved by the invention]

In the above-mentioned conventional method No. 1, since at least one channel is dedicated to each of the outgoing call control and the incoming call control, the frequency of outgoing and incoming calls is low in a wireless zone with a small amount of communication, and there is a drawback that the wireless channel is wastefully occupied.

In a wireless zone with a large amount of communication, if there is no available communication channel, even if an incoming / outgoing call is received on the common control channel, communication cannot be performed, and the control channel is wasted. Further, since the channel for transmitting from the wireless terminal station is limited, the collision rate of random access increases, and it is necessary to retransmit the transmission signal in order to increase the transmission completion rate. Therefore, the transmission connection delay increases. was there.

In the conventional method No.2 and No.3, since it is an individual control method in which one wireless terminal station exclusively occupies one wireless channel, even if the outgoing connection fails, the wireless channel is unnecessarily occupied for a certain period of time. There was a flaw.

Further, as a method for the wireless terminal station to search for an empty channel in the wireless zone at the time of transmitting a call request, the wireless terminal station stores all the wireless channels in the wireless zone, cyclically switches and receives the channels, You need to find a free channel. When a large number of wireless channels exist in the wireless zone, it has a drawback that the outgoing connection delay becomes large in order to find a free communication channel.

Furthermore, if the wireless terminal station has the possibility of moving to another wireless zone within the service area, it is necessary to change the stored content each time it moves or to store all wireless channels in the service area first. However, when there are many wireless zones in the service area or when a new wireless zone is set in the service area, it is difficult to control finding a free communication channel.

Further, in the conventional method No. 3, as a method for the wireless terminal station to search for an idle channel, the wireless base station broadcasts all the idle communication channels on the incoming control channel, and the wireless terminal station receives the broadcast information and performs the idle communication. There is a method of knowing the channel, but when a large number of wireless channels exist in the wireless zone, there is a drawback that the broadcast information becomes large and the ratio of monopolizing the incoming control channel increases.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned drawbacks and to provide a wireless communication control method for increasing the efficiency of use of wireless channels by performing efficient call origination / termination control.

[Means for solving the problem]

According to the present invention, the above objects are achieved by the means as set forth in the claims.

That is, according to the present invention, a service area is configured by one or more wireless zones, each wireless zone includes a wireless base station, and a plurality of wireless terminal stations exist in the wireless zone, and the wireless base station is In a wireless communication system having a plurality of wireless channels for controlling outgoing / incoming calls and communication with a subordinate wireless terminal station, the wireless base station divides the wireless channel into an incoming call control channel and a communication channel, Among these, a means for setting a part or all of unused communication channels not used for communication as a common transmission control channel for controlling transmission of a plurality of wireless terminal stations, and an incoming call control channel, a wireless A means for performing transmission from the terminal station using the transmission control channel includes the transmission control channel when the wireless base station starts communication with the wireless terminal station. Set the communication channel from the serial vacant communication channel is a radio communication control system having a means for performing communication using the communication channel.

[Action]

The present invention, in a wireless communication system for making and receiving a wireless terminal station using a common control channel, uses a part or all of the channel as an outgoing control channel when an empty communication channel exists, and If there is no available space, the call control channel is not provided and the call control is interrupted.

〔Example〕

FIG. 1 is a diagram for explaining the operation of the wireless communication control system of the present invention, and FIG. 1 (a) is a wireless channel configuration diagram in the case of making and receiving a wireless terminal station using a common control channel in the conventional system. FIG. 2B is a wireless channel configuration diagram when a free communication channel exists in the wireless communication control method of the present invention,
FIG. 3C shows a wireless channel configuration diagram in the case where there is no free communication channel in the wireless communication control method of the present invention and it is necessary to use the communication channel. In the figure,
The incoming call control channel for downlink is a channel for the radio base station to transmit incoming call information to the wireless terminal station, and the incoming call control channel for uplink is for the wireless terminal station to send an incoming call response signal to the base station. Is the channel of.

The uplink transmission control channel is a channel for transmitting a transmission request from the wireless terminal station to the wireless base station, and the downlink transmission control channel is a response to the transmission request from the wireless terminal from the wireless base station to the wireless terminal. Is a channel for sending to.

First, the case where there is a free communication channel shown in FIG. 1B will be described in comparison with the conventional method shown in FIG. 1A, and the case where there is no free communication channel shown in FIG. 1C will be described later. .

That is, conventionally, as shown in FIG. 1 (a), the wireless channels are set to the incoming control channels 5a, 6a, the outgoing control channels 5b,
6b Communication channels 5c to 5e and 6c to 6e are fixedly set, and the channel configuration was constant even when there were empty communication channels 5c, 5d, 6c and 6d. As shown, channels 7b, 7c, 8b and 8c of the outgoing control channels are set as outgoing control channels.

In FIG. 1 (b), the wireless terminal station waiting for an incoming call receives the incoming call control channel 7a in the existing wireless zone. The wireless terminal station controls the incoming call when the incoming information to the own station is detected, and after receiving the designation of the communication channel by the wireless base station, performs the communication on the channel.

Outgoing call control channel is the outgoing call control channel
It is broadcast by the base station information (information indicated by reference numerals 4a and 4b in FIG. 8) in 8a. When a call request transmission instruction is issued from a wireless terminal station subscriber during the incoming call waiting operation, the wireless terminal station refers to the base station information and randomly transmits the outgoing call control channel 7b or 7c to send the outgoing information. To do. As the access method of the wireless terminal station, the Aloha method,
There is a slotted aloha method.

Transmission control is performed using the transmission control channel 7b or 7c, the communication channel is designated, and then the communication is performed on the designated communication channel.

If you need more than one communication channel,
The number of channels required for transmission / reception control is reported to the radio base station, and the radio base station allocates the required number of communication channels.

Further, when the wireless terminal station has mobility and it is necessary to register the location wireless zone of the wireless terminal station, the location registration information is the outgoing transmission control channel 7b from the wireless terminal station to the wireless base station. 7c is randomly accessed and transmitted.

Further, FIG. 2 shows a block configuration diagram for explaining the operation of the radio base station, where 11a to 11d are transmitters and 12a to 12d.
Is a receiving device, 13a to 13d are signal processing units, 14 is an incoming call processing unit,
Reference numeral 15 represents a channel management unit, and 16 represents a transmission processing unit.

On the downlink incoming control channel, incoming information to the wireless terminal station received by the incoming call processing unit 14 and base station information on the outgoing call control channel managed by the channel management unit 15 are coded by the signal processing unit 13a, and the transmission device Informed by 11a. When using a free communication channel as an outgoing control channel,
The channel management unit 15 manages the channel.

The incoming call response information from the wireless terminal station is received by the receiving device 12a, transmitted from the signal processing unit 13a to the incoming call processing unit 14,
When the wireless terminal station uses a communication channel, the channel designated by the channel management unit 15 is used.

The transmission information from the wireless terminal station is received by the reception device 12b of the uplink transmission control channel managed by the channel management unit 15 and transmitted from the signal processing unit 13b to the transmission processing unit 16, and the transmission response information is the transmission processing unit 16 Is transmitted to the signal processing unit 13b from the transmitter 11b and transmitted from the transmitter 11b on the downlink transmission control channel. When using the communication channel, the channel designated by the channel management unit 15 is used.

Of course, these circuit configurations can be replaced by software means.

FIG. 3 shows a call origination / termination control flow of the wireless terminal station when there is a free communication channel in the above-described method.

Next, a case where there is no available communication channel will be described.

FIG. 1 (c) shows a wireless channel configuration diagram when there is no available communication channel in the wireless communication control method of the present invention as described above. As shown in FIG. 1, all communication channels are in use. In this case, even if an incoming / outgoing call signal is received, there is no channel to be assigned to communication, so outgoing / incoming call control is unnecessary.

When communication channels 9c to 9e and 10c to 10e are in use,
10b is set as an outgoing control channel, but if a new communication channel is required due to new incoming / outgoing calls, etc.,
Transmission control is suspended, and unnecessary transmission control channels 9b and 10b are assigned as communication channels to form a channel configuration as shown in this figure.

If there is no available communication channel and there is no outgoing control channel, the outgoing call prohibition information is transmitted by the base station information in the incoming incoming call control channel 10a, and the wireless terminal station waiting for incoming call receives the information and controls outgoing call. Know that the channel does not exist.

Next, for example, when the communication is finished and there is a vacancy in the communication channels 9e, 10e, the communication channels 9e, 10e are newly set as the transmission control channel, and the transmission in the base station information in the downlink incoming control channel 10a is performed. The prohibition is released, the transmission control channel is notified, and the transmission / reception control is restarted.

In addition, when the wireless terminal station is mobile and needs to register the location wireless zone of the wireless terminal station, it knows that the base station information is received and that the transmission control channel is communicating, The registration information is sent by randomly accessing the incoming call control channel 9a.

FIG. 4 shows a call origination / termination control flow of the wireless terminal station when there is no available communication channel in the above-described method and it is necessary to use the communication channel.

〔The invention's effect〕

As described above, according to the present invention, when there is an available communication channel, a part or all of the available communication channel is set as a transmission control channel to provide a means for effectively utilizing an unused wireless channel. Will be done.

Therefore, when there are multiple free communication channels,
By setting multiple outgoing control channels, the collision rate of random access is reduced and outgoing connection delay is reduced.

FIG. 5 shows the average outgoing connection delay when the outgoing control channel is randomly accessed.

The access method is the slotted Aloha method, and the retransmission is repeated until the transmission is successful, and the retransmission interval is set to 2 seconds.
The horizontal axis represents the signal occurrence rate (the number of signals / slot interval), and the vertical axis represents the transmission connection delay in the wireless section. Reference numeral 20 indicates a case where the transmission control channel is one channel, 21 indicates a case where the transmission control channel is two channels, and 22 indicates a case where the transmission control channel is three channels.

From Fig. 5, when the signal occurrence rate is 0.3 (the number of signals / slot interval), the transmission control delay in the wireless section is increased by increasing the transmission control channel from 1 channel to 2 channels.
It can be seen that it can be reduced to about 40%. Signal volume during the busy hour
When the number of communication channels with a call loss of 3% is set for a wireless zone of 80 erlangs, the probability that there is a free communication channel during the busy hour is about 64%, and this method is widely applicable.

Also, when assigning the wireless channels in the wireless zone to the communication channel and the control channel, the outgoing control channel is not fixedly set. By using the wireless channel as the communication channel, it is possible to reduce the call loss due to the absence of the idle communication channel, as compared with the case where the transmission control channel is fixedly set.

FIG. 6 shows a call volume that can be carried when a wireless channel which has been conventionally assigned as a transmission control channel is used as a communication channel by this method.

The horizontal axis indicates the number of communication channels, and the vertical axis indicates the call volume that can be carried by each channel number. 17 is the case where the number of communication channels is determined so that the call loss is 3% in the conventional method, and 18 is the case where this method is used.
If the number of communication channels is increased by 1 compared to 17, 19
Indicates the call volume that can be carried when the number of communication channels increases by two.

From Fig. 6, by applying this method to the conventional wireless zone with 3 communication channels and 1 transmission control channel, the call volume that can be carried, that is, the subscriber capacity is increased by about 1.8 times. I understand.

Further, it is expected that various communication services will be required by digital communication systems in the future, and the number of channels required for wireless communication will differ depending on the type of service.

Therefore, in the individual transmission control, which is characterized in that the transmission control and the communication are performed on the same channel, it becomes difficult to allocate channels to various communications. According to this method, which uses common control for controlling transmission of a plurality of wireless terminal stations on one channel as a transmission control method, it is possible for the wireless base station to allocate the required number of communication channels using the control channel. In addition, it is easy to control transmission when a large number of communication channels exist in the wireless zone, and has system expandability such as an increase in wireless zones and an increase in wireless channels, which is an excellent control method.

It can be said that the effect of the present invention is great in that the advantages of the common control described above are utilized, the wireless channel is effectively used, and the transmission connection delay is reduced.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining the operation of the wireless communication control system of the present invention, and FIG. 1 (a) is a wireless channel configuration diagram of the conventional system,
2B is a wireless channel configuration diagram in the case where there is a free communication channel, and FIG. 7C is a wireless channel configuration diagram in the case where there is no free communication channel and it is necessary to use the communication channel. Fig. 4 is a block diagram for explaining the operation of the wireless base station, Fig. 3 is a diagram showing a flow of call control of the wireless terminal station when there is an empty communication channel in this system, and Fig. 4 is a communication channel in this system. Fig. 5, Fig. 5 and Fig. 6 which show the flow of control of incoming and outgoing radio terminal station when there is no free space and it is necessary to use a communication channel, and Fig. 5 is a diagram for explaining the effect of the present invention. FIG. 6 is a diagram showing an average transmission connection delay when the transmission control channel is randomly accessed, FIG. 6 is a diagram showing a call volume that can be carried when the number of communication channels in the wireless zone is increased as compared with the conventional method, and FIG. Base station and multiple Wireless system configuration diagram of the terminal station, FIG. 8 is a diagram showing an example of a signal structure of incoming control channel of the downlink from the radio base station to the wireless terminal station, Figure 9, second
FIG. 11 is a flow chart showing call control of a conventional wireless terminal station. FIG. 9 shows a case where communication, call control, and call control are performed on different channels, and FIG. FIG. 11 is a diagram showing a case where individual control of outgoing / incoming of the terminal station is performed, common control is performed by using a dedicated channel, and outgoing control is performed by individual control using a communication channel. 1 ... Wireless base station, 2a-2c ... Wireless terminal station, 3a-3d ...
Incoming call information, 4a, 4b ...... Base station information, 5a to 5e ...... Uplink wireless channel, 6a to 6e ...... Downlink wireless channel, 7a to 7e ...... Uplink wireless channel, 8a to 8e ...... Downlink wireless channel Channels, 9a to 9e ... Uplink wireless channels, 10a to 10e ... Downlink wireless channels, 11a to 11d ... Transmitting devices, 12a to 12d ... Receiving devices, 13a to 1
3d …… Signal processing unit, 14 …… Incoming call processing unit, 15 …… Channel management unit, 16 …… Outgoing processing unit, 17 …… Call volume that can be carried by the conventional method, 18 …… When one communication channel is added Call volume that can be carried, 19 ...... Call volume that can be carried when the number of communication channels is increased by 2 channels, 20 ... Average outgoing delay time when the transmission control channel is 1 channel, 21 ... Average when the transmission control channel is 2 channels Transmission delay time, 22 …… Average transmission delay time when there are 3 transmission control channels

Claims (1)

(57) [Claims] 1. A service area is composed of one or more wireless zones, each wireless zone includes a wireless base station, and a plurality of wireless terminal stations are present in the wireless zone, and the wireless base station is under control of the wireless base station. In a wireless communication system having a plurality of wireless channels for controlling outgoing / incoming call and communication with the wireless terminal station, the wireless base station divides the wireless channel into an incoming call control channel and a communication channel, Among these, a means for setting a part or all of idle communication channels not used for communication as a common transmission control channel for controlling transmission of a plurality of wireless terminal stations, and an incoming control channel for receiving an incoming call to the wireless terminal station, a wireless terminal Means for transmitting from the station using the transmission control channel, and when the wireless base station starts communication with the wireless terminal station, the wireless communication including the transmission control channel Wireless communication control method, characterized in that a communication channel is set from among the communication channels and means for performing communication using the communication channel is provided.