JPH1155730A - Wireless communication control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a call damage which occurs since incoming information in a control channel does not reach a radio slave machine by controlling the transmission/reception of the control channel so that it is not interfered. SOLUTION: For transmitting incoming information from a radio base station 10, the radio slave machine 11 which synchronously waits for information receives incoming information from the base station at timing when the slave machine waits incoming information. The presence of an interference wave in a transmission position is judged before transmission at timing when the base station transmits the incoming information. When the interference wave exists, the base station holds transmission. The switching of the reception timing of incoming information is instructed by control information transmitted at the different timing from the base station. The radio slave machine 11 is shifted to a state where it waits for information in a specified position by the switching instruction of incoming information by control information to a state where it continuously waits for control information. Incoming information which is held is transmitted from the base station at timing without the interference wave. The radio slave machine 11 receives the incoming information and executes the sequence operation of an incoming call.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio communication device and a radio communication system, and more particularly to a radio communication control device, a radio telephone, and a private branch exchange used as a private-use base station of a simplified digital cordless telephone system PHS. Related to the system.

[0002]

2. Description of the Related Art The standard of the PHS digital cordless telephone system was established by the Association of Radio Industries and Businesses in December 1995.
It is defined in the second generation of the second generation cordless telephone system standard issued on March 26.

According to this, the base station radio control apparatus has a maximum of four simultaneous control channels and communication channels in a time-division manner, and transmits control information from the radio base station to the radio area by the control channel. I do. When a call is made from a wireless handset existing in the area of the wireless base station, information requesting allocation of a communication channel is transmitted to the wireless base station at the timing of the control channel. The wireless base station measures the interference wave with respect to the frequency of the communication band, and notifies the wireless slave unit of the controllable channel information and the communicable frequency and slot where there is no interference wave. The wireless slave sets a wireless link with the wireless base station using the allocated communication channel, and establishes a call. The base station notifies the other party of the call setting request through the exchange, and can start a call when the call is established with the other party.

[0004] When an incoming call arrives at a slave unit, the base station notifies the slave unit of incoming call information through a control channel. Then, the slave unit transmits a signal requesting assignment of a communication channel.
The radio base station notifies the communicable frequency and the division slot in the same manner as at the time of calling. The wireless handset sets up a wireless link to communicate with the base station through the assigned communication channel,
After the call is established with the other party through the exchange, the call is started.

[0005] The base stations are connected to the same exchange by a line, and the base stations are synchronized by the line.

[0006] The control information transmitted from the control channel is transmitted at regular intervals, and the wireless slave unit synchronizes with one wireless base station and receives the control information from the wireless base station and receives the control information from the wireless base station based on the timing at which the control information is transmitted. Only information is received. FIG. 2 shows a control channel transmission control flow chart of a conventional base station. The conventional base station measures the interference wave of the control channel that is the transmission position of the base station when the power is turned on or by starting the control channel transmission from the exchange to which the wireless base station is connected, and the transmission position of the transmission position with less interference is measured. Transmit the control channel on the slot. After the control channel transmission is started, the control channel is transmitted at regular intervals in accordance with the synchronization from the exchange. FIG. 3 shows a transmission pattern of the control channel from the base station.

[0007] The radio section is TDMA-TDD of 8 slots.
It is transmitted and received by the method. The eight slots are composed of four transmission slots and four reception slots, and transmission of modulated transmission data is started for each head of the transmission slots. The transmission of the control channel is performed in a fixed slot in the four slots. As a result, transmission in the transmission slot every 5 ms is performed in the channel for communication. As for the transmission timing of the control channel, the transmission timing is transmitted every 5 ms after a predetermined interval. The interval value is peculiar to the system. For example, in an office PHS system, this interval is equal to one of the transmission timings of every 30 units.
This is performed at intervals of 50 ms.

[0008] The information transmitted from this control channel is:
Broadcast information, control information, and incoming information are set as a set at regular intervals, for example, in the order of the combination as shown in FIG. 3, and the combination is repeatedly transmitted. The frame structure transmitted on the control channel is 2 frames in one slot of 625 μs.
Transmit 60-bit data. Among them, 108 bits are used as a control signal for a control channel. Before the 108 bits for the control signal, a 32-bit unique word for distinguishing between a communication channel and a control channel is added, and after the control signal, a 16-bit obtained by performing an operation on the control information for error detection is added. A frame for broadcast information, control information, and incoming information is used as the 108-bit pattern of the control signal. The first four bits of each frame are channel type bits for distinguishing the type of frame.

[0009] The broadcast information frame and the incoming information frame are only from the radio base station and the radio slave, but the control information frame is bidirectional from the radio base station to the radio slave and from the radio slave to the radio base station. When transmitting from the wireless base station, the source identification code 42 bits of the wireless base station are transmitted following the channel type bit. Broadcast information and incoming information frame remaining 6
Two bits are data. 2 for control information frame
An 8-bit wireless terminal arrival identification code follows, and 34 bits become data. The control channel transmits the frames at regular intervals in the same combination.

On the other hand, when the wireless slave enters a steady standby state, it receives control information at the timing of receiving only the notification information and the incoming call information, thereby saving the battery of the wireless slave. As for the incoming call information, the transmitting position of the incoming call information is changed for each incoming call group of the handset by dividing the wireless slave into several groups. For example, in FIG. 4, the incoming call information is divided into four groups, and the wireless slaves are also divided into four groups. Among them, the wireless slaves belonging to the second group receive at the position of only the incoming call information at the timing of the incoming call group 2. Controlling. The incoming call group of the wireless handset is uniquely determined for the wireless handset. The transmission timing and the transmission order of the control channel are constant after the base station starts transmitting the control channel.

[0011]

The relative position of transmission information of a control channel between conventional radio base stations is fixed, and there is no interference wave from another radio base station in a slot in which the control information is reported. Alternatively, transmission was performed based on the result of measuring the reception level by observation before transmitting a slot with low interference. However, if there is a wireless base station of another system that is not synchronized in this wireless base station system, when transmission starts with each other, the control channel is transmitted in a different slot, but the control channel between the wireless base stations is out of synchronization because , The notification information is transmitted at the timing when the incoming information is transmitted on another control channel.

At this time, there is a possibility that the incoming information does not reach the wireless handset due to interference, and the incoming call cannot be received. For example, in a PHS private system, a home system that synchronizes itself and a business system that synchronizes simultaneously with a private branch exchange use the same frequency control channel and there may be an error in the synchronization timing. In some cases, transmission of own control channel may be performed at another control channel transmission timing, and there is a possibility that a state in which a call cannot be received may occur.

[0013]

When transmitting incoming information from a wireless base station, a wireless slave unit that is waiting in synchronization receives the incoming information from the base station at the timing when the slave unit waits for the incoming information. At the timing when this base information is transmitted by the base station, the presence or absence of an interference wave at the transmission position is determined before transmission. If there is an interference wave, the base station suspends transmission. Control information transmitted at another timing from the base station instructs switching of the reception timing of the incoming information. The wireless handset shifts from a state of waiting at a specific position to a state of continuously waiting for control information in response to an instruction to switch incoming information according to control information. The base station transmits the suspended incoming call information at a timing when there is no interference wave. The wireless handset receives the incoming call information and performs an incoming call sequence operation.

[0014]

FIG. 1 shows a wireless communication control system according to a first embodiment. 10 is a wireless base station, 11 is a wireless handset, 1
Reference numeral 2 denotes an exchange for controlling the radio base station. Each base station transmits broadcast information on the information channel by the method described in the above-mentioned conventional technique. The wireless handset searches for a receivable radio wave and matches the control channel transmission timing of the base station transmitting the system-specific system ID indicated by the first 29 bits of the source identification code of the wireless base station as a control channel. You will be in a state of waiting. After the power is turned on, the wireless handset performs a location registration operation with respect to the base station that is first in the standby state. The location registration operation is notified to the twelve exchanges, and the exchange has information as to which base station area the wireless slave unit is located in. The radio base station forms one area with a plurality of base stations.

When an incoming call arrives at the wireless handset, the exchange notifies all base stations in the area where the handset is registered to transmit incoming information. The wireless handset receives incoming information from the waiting base station and performs an incoming call operation. When the wireless slave unit cannot move and maintain synchronization with the base station that has been waiting, it searches for a control channel and enters a state of waiting for a new base station. When the wireless handset moves across the area of the base station, the handset notifies the exchange of the location registration again at the base station in the new area through the wireless base station.

FIG. 5 shows a system configuration diagram of the control of the base station. Reference numeral 101 denotes a wireless public base station. 102 is a transmission system radio control unit, 103 is a radio synchronization control unit, 104 is a data processing unit, 105 is a control microcomputer, 106 is a memory for storing programs and data, 107 is a reception system radio control unit, and 108 is a reception level detection unit. , 109 is a line control unit,
Reference numeral 110 denotes an ISDN line connected to the exchange. Programs such as control control of transmission of a control channel and transmission / reception sequence control are stored in 106 and read out by the control microcomputer 105 and executed. The synchronization timing for transmission control is generated as timing synchronized with the line connected to the exchange by the line control unit 109 and synchronized with the radio unit at 103.

The data processing unit 104 generates and assembles wireless data to be transmitted as a frame. The assembled radio transmission frame is modulated by the transmission system radio control unit 102 according to the transmission synchronization timing generated in 103, and transmitted over a radio line. Assuming that the data modulation time and the transmission timing in the wireless section are constant, the synchronization timing of the line control unit becomes the head of the transmission data. FIG. 3 shows a control channel transmission timing diagram as an example of a system for business use. Broadcast information must be at least 1 for this combination
Sent twice. The wireless handset waits at the timing of receiving this control information. That is, in order to perform battery saving in the slave unit, the power of the wireless circuit in the slave unit is turned off at the timing when control information is not transmitted or at the timing when unnecessary information is transmitted.

The slave of this system receives only the notification information as the incoming information. The incoming call information is grouped by the number of the wireless handset, and the incoming information of the handset is notified at the incoming information transmission timing corresponding to the handset of each group.
For example, an individual number is assigned to a serial number for a slave unit in the system. Assume that the number of incoming calls is 4 as an example of the system. In this case, the incoming call information is transmitted from the incoming call groups 1 to 4 at the timing shown in FIG. Each wireless slave unit sets a remainder obtained by dividing the assigned individual number by 4 as a group of the slave units. The wireless handset enters a standby state at a timing of receiving only the incoming call information of the incoming call group. Therefore, when the wireless base station is transmitted at the timing shown in FIG. 4, the wireless slave device has only to receive two slots in 1.2 s.

When a radio base station of another system exists near the radio base station of this system, the control channel is transmitted at the same frequency between the radio base stations. Before starting transmission from the radio base station, the radio base station measures the electric field strength for all slots at the transmission timing. That is, measurement is performed for the control channel interval in four transmission slots. The control channel transmission is started at the slot position where the interference level is the lowest. The transmission is similarly started in the radio base station in another system and the radio base station in another system.

FIG. 6 shows a control flow chart of the base station of the present invention. Conventionally, once transmission of a control channel is started, a certain pattern is transmitted at a certain timing for transmission of a control channel. However, a slot of a timing to transmit before transmitting a control channel at a timing of transmitting incoming information. Measure the interference wave at. The interference wave is measured at several points in the slot and takes the maximum value. The timing of measuring the interference wave is generated in synchronization with the wireless transmission slot by the wireless synchronization control unit 103 in FIG. The level of the interference wave is measured by a reception level detection unit 108. When the interference wave is equal to or larger than the threshold value, the transmission of the incoming information is temporarily suspended, and the broadcast information is notified that there is a change in the incoming information. Thereafter, the wireless base station attempts to transmit incoming call information at another incoming call group position. These processes are built in the 106 as a program, and the control microcomputer 105 controls each unit.

On the other hand, when the wireless slave unit is notified of the presence of an interference wave in its own incoming call group by the broadcast information, there are two types of operations as the wireless slave unit. 1) Switch from intermittent reception to continuous reception of battery saving. 2) The intermittent reception timing of the battery saving is changed, and the reception timing is changed so that reception can be performed by another incoming call group. 1) corresponds to claim 3 and 2) corresponds to the processing of the wireless terminal of claim 4.

FIG. 7 shows a configuration diagram of the control system of the wireless slave unit. 201 indicates a wireless slave unit. 202 is a transmission system radio control unit, 203 is a radio synchronization control unit, 204 is a data processing unit, 205 is a control microcomputer, 206 is a memory for storing programs and data, 207 is a reception system radio control unit, 20
8 denotes a reception operation control unit, and 209 denotes an operation processing unit. Programs such as control control of control channel reception and transmission / reception sequence control are stored in 206, and read out and executed by the control microcomputer 205. The wireless handset performs control to turn off the circuit power except for the reception timing necessary for saving the battery. This is the control microcomputer 2
05.

The control microcomputer turns off the power of each circuit.
However, the control microcomputer itself operates only the external timer,
Enters the mode that does not consume power when the timer is interrupted. This saves the battery. When the microcomputer for control is started by the timer, the power supply such as the wireless circuit section of the receiving system is turned on and the microcomputer is ready to receive.

When the control method of the wireless slave unit is 1), the control channel is continuously received. That is, the receiving operation control unit 206 is controlled by the processing of the control microcomputer 205 and the receiving wireless control unit 207 is continuously operated. That is, the receiving radio section is continuously operated without receiving the battery or saving the radio section of the receiving system for a certain period of time. It is determined based on the system ID in the control channel whether or not the control channel is from the wireless base station of the own system. When the frame received at 207 is processed by the data processing unit at 204, the system ID of the received frame is extracted.

The system ID is the data of the first 29 bits of the calling identification code, which is common to the radio base stations in the radio control system and is unique to one system. Therefore, the calling identification code of the own system can be determined. If the incoming information is received. After receiving the incoming call information, a request for a communication channel is made to the radio base station by the control information from the radio personal station. The wireless base station allocates a communication channel and notifies the wireless slave device of the control information.
Then, a communication channel is established between the base station slaves, a call is set, and a call is started. FIG. 8 shows the reception operation timing of the slave unit at that time.

In the case of 2), the reception timing of the control channel is changed. This is performed by changing the reception interval in the reception operation control unit 208 under the control of the control microcomputer 205. In the reception interval control of the wireless handset, the receiving position of the incoming call information of each incoming call group is determined based on the broadcast information receiving position. The position of the incoming call information is transmitted from the notification information. The receiving operation is performed with another incoming call group by changing the incoming call information receiving position. The instruction of the paging group is notified by the radio base station by broadcast information. Incoming information is transmitted at the changed transmission position from the radio base station that has issued the broadcast information, and the wireless handset waits for reception at the changed incoming information position. Continue the incoming call operation.

That is, the control information signal of the control channel
A request is made to the base station for wireless link assignment for communication, and a channel for communication with the base station is set in a channel assigned by the base station. An incoming response is transmitted to the base station from this channel. After receiving the call, the base station transmits the call setting from the other party. After the reception and transmission of the call setting, after authentication with the exchange through the base station, if a call is set up with the other party, the communication state is established. .

[0028]

According to the present invention, the call loss caused by the fact that the incoming information in the control channel does not reach the wireless handset due to the interference of the control channel between the radio base stations is reduced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a wireless communication control system according to an embodiment of the present invention.

FIG. 2 is a control system flow diagram of a conventional base station.

FIG. 3 is a control channel transmission timing diagram of a conventional base station.

FIG. 4 is a reception timing of each slave unit by a control channel.

FIG. 5 is a configuration diagram of a control system of a wireless base station.

FIG. 6 is a control system flow diagram of a base station.

FIG. 7 is a configuration diagram of a control system of the wireless slave device.

FIG. 8 is a timing chart of a slave unit receiving operation.

[Explanation of symbols]

10: wireless base station, 11: wireless slave unit, 1
Reference numeral 2 denotes an exchange, 101: a radio base station, 102: a transmission radio control unit, 103: a radio synchronization processing unit, 104: a data processing unit, 105: a control microcomputer, 106: a memory, 107: a reception radio control unit, 108 ... Reception level detector, 109 ... Line controller, 110 ... IS
DN line, 201: wireless slave unit, 202: transmission wireless control unit, 203: wireless synchronization control unit, 204: data processing unit, 205: control microcomputer, 206: memory,
207: reception system radio control unit, 208: reception operation control unit.

Claims (4)

[Claims] A wireless communication device for simultaneously controlling wireless channels on a plurality of slots in a time-division manner, comprising: a communication channel; a wireless base station having a channel for controlling the communication channel; A wireless handset that is synchronously waiting to receive only control information and incoming information,
In a wireless communication system including an exchange for controlling a wireless base station, when there is another radio wave that interferes during transmission of a control channel, a device that transmits at a timing different from the transmission timing of the detected radio wave, and a control channel A wireless base station provided with a unit for notifying the wireless slave device that the transmission slot has been changed, and a device for receiving information whose transmission slot has been changed, changing the reception operation, and receiving a control channel. A wireless communication control system comprising a wireless slave unit and controlling transmission and reception of a control channel so as not to interfere. 2. A radio communication apparatus which simultaneously controls radio channels on a plurality of slots in a time-division manner and has a communication channel on one side and a control channel for controlling a communication channel on the other side. A wireless communication control device comprising: a device for detecting other radio waves that cause interference; a device for transmitting control channel transmission timings at different timings; and means for transmitting in a slot free of interference waves. 3. The wireless communication control system according to claim 1, further comprising: means for continuously performing a receiving operation based on information from a wireless base station, wherein said wireless slave device performs a receiving operation at predetermined intervals. Features a wireless handset. 4. The wireless communication control system according to claim 1, wherein the wireless slave unit performs a receiving operation at a fixed interval, and further includes means for changing a receiving operation interval based on information from a wireless base station. And a wireless handset.