JPH09187075A - Radio communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent occurrence of malfunction of the system due to residual low speed control in a memory. SOLUTION: Storage memories 101, 103 for high speed control data and storage memories 102, 104 for low speed control data are separately provided and the storage content of the storage memories 102, 104 for low speed control data is cleared for transmission and reception by a command from a control section 100. Thus, in the call processing sequence switched from low speed control data into high speed control data on the way, residual low speed control data are surely aborted at the end of one processing unit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication system for transmitting / receiving control data between a wireless base station and a wireless terminal.

[0002]

2. Description of the Related Art Conventionally, in a wireless section between a wireless base station and a wireless terminal, a high speed communication channel used for high speed control data transmission and communication data transmission and a low speed communication channel for low speed control data transmission are provided. In a wireless communication device that transmits and receives control data via a low speed communication channel during normal data communication via a high speed communication channel, the channel used for call control data transmission is 1 depending on the state of the device.
One control event is realized by exchanging control data using only one of the high speed channel and the low speed channel.

[0003]

However, since the above-mentioned conventional wireless communication equipment uses two kinds of communication channels having different speeds for each call control event, the situation change during the call control event ( For example, there is a problem that it is difficult to control (for example, deterioration of line quality).

Specifically, in a low-speed channel, a recovery process (for example, interference avoidance process, handover process, etc.) accompanying the deterioration of wireless channel quality is required during the control sequence for call control. However, these processes cannot be performed rapidly.

As a method for rapidly performing these processes, it is preferable to immediately perform communication of control data for recovery processing on a high speed channel, but processing is performed by residual data being transmitted on a low speed channel. There is a possibility that an event may occur in which the consistency with the internal control is lost.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a wireless communication device capable of preventing malfunction caused by residual low speed control data.

[0007]

In order to achieve the above object, the present invention uses both high speed control data transmission and communication data transmission on a wireless line provided between a wireless base station and a mobile terminal. A wireless communication system having a high-speed communication channel for transmitting low-speed control data and a low-speed communication channel for transmitting low-speed control data, and transmitting / receiving control data via the low-speed communication channel during normal data communication via the high-speed communication channel. A first memory for storing data related to transmission in the high speed control data, a second memory for storing data related to transmission in the low speed control data, and a reception for receiving in the high speed control data Third memory for storing such data, fourth memory for storing data related to reception among the low speed control data, means for clearing the second memory and fourth memory The provided, during the call control by the low speed control data, when receiving the high speed control data, performs a predetermined control in accordance with the high speed control data,
The residual control data in the second memory and the fourth memory is discarded.

[0008]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram showing a configuration of a wireless communication terminal used in a wireless communication system according to an embodiment of the present invention. Note that here, a wireless communication system using a personal handyphone system (PHS) as a medium is assumed as a system having a high-speed communication channel and a low-speed communication channel.

In FIG. 1, 100 is a control unit for controlling the operation of the entire wireless communication terminal, 101 is a transmission waiting high speed control data storage memory for storing high speed control data to be transmitted on a high speed communication channel, and 102 is A low-speed control data storage memory waiting for transmission to store low-speed control data to be transmitted on the low-speed communication channel, 103 is a reception high-speed control data storage memory for storing high-speed control data received on the high-speed communication channel, and 104 is A low-speed control data storage memory for storing low-speed control data received on a low-speed communication channel.

Each of the storage memories may be a FIFO memory or a dual port RAM.
It may also be in the shared RAM format.

Reference numeral 105 denotes a TDMA framer for assembling a TDMA data frame by time-division multiplexing high-speed communication channel data and low-speed communication channel data, 106.
Is a TDMA deframer for extracting high-speed communication channel data and low-speed communication channel data from a TDMA frame, 107 is a transmitting unit, 108 is a receiving unit, 109 is a frequency setting synthesizer, and 110 is an antenna switching for switching the antenna 12. The section 111 is an ADPCM codec for voice communication.

Reference numeral 1 is a signal line for requesting a clear of the transmission waiting low speed control data storage memory 102, and 2 is a signal line for requesting a clear of the reception low speed control data storage memory 104.

FIG. 2 is a diagram showing a communication form of the wireless communication system according to the present embodiment. In FIG.
Is a communication control device (CE) for controlling a circuit network (not shown),
201 and 202 are wireless base stations (C) connected to the communication control device 200 by wired communication paths 210 and 220, respectively.
S) and 203 are wireless communication terminals (PS) connected to the wireless base stations 201 and 202 by wireless lines.

The above-mentioned radio communication terminal moves from the communication cell 205 covered by the radio base station 1 (CS1) 201 to the radio base station 2 adjacent to it at the time of handover processing described later.
Move to the communication cell 206 that the (CS2) 202 covers,
The connection of the wireless line is switched from CS1 to CS2.

FIG. 3 shows that when the wireless communication terminal according to the present embodiment performs a handover process, the wireless communication terminal (P
FIG. 6 is a diagram schematically showing the wireless line quality detected in S) with the elapsed time as the horizontal axis and the line quality as the vertical axis. In addition,
Here, the received electric field strength is used as a criterion for judging the wireless line quality.

In FIG. 3, 301 is a communication continuation limit level which is a limit level of line quality for continuing good communication, and 302 is a connection continuation limit level which is a limit level of line quality for continuing connection. Indicates. Again 31
Is a handover process when the wireless communication terminal (PS) moves in the communication cell at a low speed, 32 is a handover process when the wireless communication terminal (PS) moves at a high speed, and 33 is a wireless communication It is a figure which shows typically the time change of each line quality when a terminal (PS) starts a movement at low speed initially, and a movement speed changes to high speed from the middle.

Therefore, the sequence in each of the above handover processes will be described in detail.

FIGS. 4 to 6 are sequence charts relating to low speed handover processing, high speed handover processing, and handover processing when low speed control data and high speed control data are mixed.

FIG. 4 is a diagram showing a sequence relating to low speed handover processing.

A wireless terminal (PS) 201 (CS1-PS in FIG. 4) connected to the wireless base station 1 (CS1) 201.
(Indicated as “in communication” in between) moving at a low speed in the direction of the radio base station 2 (CS2) 202, FIG.
As shown in, the line quality gradually deteriorates with the passage of time, and when the line quality deteriorates below the communication continuation limit level, the handover process is started, and the handover process sequence by the low-speed control data is started.

These processes are performed by the "handover permission", "synchronization burst" and "S" shown by broken lines in FIG.
It is executed by exchanging signals indicated by "ABM" and "UA". As a result, before the connection continuation limit level is reached, the state shown as “in communication” between CS2-PS in FIG. 4, that is, the radio base station 2 (CS2) 202.
The switching of the connection to is completed, and the line quality is restored to the call continuation limit level or higher (corresponding to part A in FIG. 3).

All the control information on the wireless line relating to the above-mentioned handover processing is transmitted using the low speed channel, and the high speed channel performs the handover in the state of being used for normal data communication. be able to.

In FIG. 5, the wireless terminal (PS) 203 connected to the wireless base station 1 (CS1) 201 is connected to the wireless base station 2 (C
FIG. 5 is a diagram showing a sequence relating to a handover process when moving at a high speed in the direction of S2) 202.

In this case, as shown in FIG. 3, the line quality deteriorates rapidly, and when it deteriorates below the communication continuation limit level and the connection continuation limit level, the radio base station 1
The line with the (CS1) 201 is disconnected, and the sequence following the “link channel establishment request” in FIG. 5 is executed to start the reconnection-type handover process. That is, as shown by the thick solid line in FIG. 5, the handover processing sequence by the high speed control data is started, and as a result, the reconnection of the line with the radio base station 2 (CS2) 202 is completed. Then, as indicated by B in FIG. 5, the line quality is restored to the call continuation limit level or higher.

In this sequence, all the control information on the wireless line related to the handover processing is transmitted using the high speed channel, and normal data communication is temporarily interrupted before the handover. .

Next, a handover process when low speed control data and high speed control data are mixed will be described.

The wireless terminal (PS) 203 connected to the wireless base station 1 (CS1) 201 is connected to the wireless base station 2 (CS2) 2
When moving in the direction 02 at a low speed, the line quality gradually deteriorates as described above, and the handover process is started when the line quality deteriorates below the communication continuation limit level, and the handover process sequence by the low speed control data is started. However, when the line quality deteriorates rapidly during the sequence processing and becomes below the connection continuation limit level (C in FIG. 3).
Part), as shown in FIG. 6, once the line with the radio base station 1 (CS1) 201 is disconnected, the reconnection-type handover process is started, and the high-speed control data is used. Enter the handover processing sequence.

Then, the line is reconnected to the radio base station 2 (CS2) 202 to restore the line quality to the communication continuation limit level or higher (D portion in FIG. 3), and then the control unit 10 is connected.
By sending a predetermined signal through the signal lines 1 and 2 respectively in response to the instruction of 0, the transmission waiting low speed control data storage memory 10
2, and the reception low speed control data storage memory 104 is cleared. As a result, the residual low speed control data due to the multiplexed handover processing is surely discarded.

As described above, according to this embodiment, the high-speed control data storage memory and the low-speed control data storage memory are independent, and the low-speed control data storage memory for both transmission and reception is instructed by the control unit. By making it possible to clear the stored contents, it is possible to reliably discard the residual low-speed control data at the end of one processing unit even in a call processing sequence in which the low-speed control data is switched to the high-speed control data on the way. It is possible to prevent malfunction due to residual low speed control data of the wireless communication system.

In the above embodiment, the personal handyphone system (PHS) has been described as an example of the wireless communication system having both the low speed communication channel and the high speed communication channel. The system is not limited to this, and can be applied to a voice-type analog radio communication system such as a digital radio communication system and an analog cordless telephone system having a data transmission function outside the voice band.

The present invention may be applied to a system composed of a plurality of devices or an apparatus composed of a single device. Further, it goes without saying that the present invention can be applied to the case of being implemented by supplying a program to a system or an apparatus. In this case, the storage medium storing the program according to the present invention constitutes the present invention. Then, by reading the program from the storage medium into the system or device, the system or device operates in a predetermined manner.

[0033]

As described above, according to the present invention,
By providing a memory for storing high-speed control data and a memory for storing low-speed control data independently so that the memory for storing low-speed control data can be forcibly cleared, a call that switches from low-speed control data to high-speed control data on the way Also in the control, the residual low speed control data can be surely discarded, the system malfunction due to the residual low speed control data can be prevented, and the system can be accurately controlled.

[0034]

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a wireless communication terminal according to an embodiment of the present invention.

FIG. 2 is a diagram showing a communication form of a wireless communication system according to the present embodiment.

FIG. 3 is a diagram showing a change in wireless channel quality according to the embodiment.

FIG. 4 is a sequence diagram showing a handover process (low-speed control data) according to the embodiment.

FIG. 5 is a sequence diagram showing a handover process (high-speed control data) according to the embodiment.

FIG. 6 is a sequence diagram showing handover (mixing of low-speed control data and high-speed control data) according to the embodiment.

[Explanation of symbols]

 1, 2 signal lines related to memory clear request 100 control units 101 to 104 control data storage memories 105 and 106 TDMA framer 107 transmission unit 108 reception unit 110 antenna switching unit 111 ADPCM codec 200 line control device 201, 202 radio base station 203 radio Communication terminal

Claims (6)

[Claims] 1. A high-speed communication channel used for both transmission of high-speed control data and communication data and a low-speed communication channel for transmitting low-speed control data on a wireless line provided between a wireless base station and a mobile terminal. A wireless communication system for transmitting and receiving control data via the low-speed communication channel during normal data communication via the high-speed communication channel, storing data related to transmission among the high-speed control data, A first memory; a second memory for storing data related to transmission in the low speed control data; a third memory for storing data related to reception in the high speed control data; A fourth memory for storing data related to reception, and means for clearing the second memory and the fourth memory, wherein during the call control by the low speed control data, A radio communication system, wherein when the high speed control data is received, predetermined control is performed according to the high speed control data and the residual control data in the second memory and the fourth memory is discarded. 2. The first memory, the second memory, and the third memory
2. The wireless communication system according to claim 1, wherein the memory and the fourth memory are FIFO memories. 3. The first memory, the second memory, and the third memory
2. The wireless communication system according to claim 1, wherein the memory and the fourth memory are dual port RAMs. 4. The first memory, the second memory, and the third memory
2. The wireless communication system according to claim 1, wherein the memory and the fourth memory are memories of a shared RAM type. 5. The wireless communication system according to claim 1, wherein the wireless communication system is a personal handyphone system (PHS). 6. The wireless communication system according to claim 1, wherein the wireless communication system is a voice analog wireless communication system.