JPH1051853A - Mobile radio data communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stop data transmission reception for data terminal equipments when execution of hand-over processing or channel changeover processing is started in the mobile radio data communication system for making data communication between the data terminal equipment connecting to a mobile terminal equipment and the data terminal equipment connected to a digital mobile telephone network via a digital wired line. SOLUTION: A mobile terminal equipment 10 and a radio base station 11 send pattern data consisting of a prescribed data pattern repetitively to communication adaptors 18, 19 interposed between data terminal equipments 16, 17 from the start of execution of hand-over processing or channel changeover processing till its end. Upon the detection of the pattern data, the communication adaptors 18, 19 stop the data transmission reception of the data terminal equipments 16, 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital mobile telephone network having a plurality of mobile terminals and a plurality of radio base stations, using a digital mobile telephone network. The present invention relates to a mobile radio data communication system that performs data communication with a data terminal connected via a line.

[0002]

2. Description of the Related Art In general, digital car telephone networks and PHs
2. Description of the Related Art In a digital mobile telephone network such as an S network, a radio signal obtained by A / D converting an analog voice signal, which is speech voice, into a digital voice signal by a predetermined voice coding method and digitally modulating the digital voice signal by the A / D conversion. Is transmitted and received between the mobile terminal and the radio base station.

In such a digital mobile telephone network, a communication channel used for transmitting and receiving radio signals is divided into a plurality of time slots as an access method in a radio section between a mobile terminal and a radio base station. Division multiplexing (TDMA: Time Divisio
n Multiple Acces).

In such a digital mobile telephone network, the continuity of the call is improved by sequentially changing the radio base station for transmitting and receiving radio signals to and from the mobile terminal as the mobile terminal moves. It is guaranteed. The process of changing the radio base station that transmits and receives radio signals to and from the mobile terminal in this way is referred to as “handover process”.

[0005] Even if the mobile terminal does not move, the quality of radio signals transmitted and received between the mobile terminal and the radio base station may deteriorate due to radio interference from nearby mobile terminals. Therefore, in such a case, the radio base station that transmits and receives the radio signal to and from the mobile terminal is not changed, but the communication channel used to transmit and receive the radio signal is changed. The process of changing the communication channel used for transmitting and receiving a radio signal between the mobile terminal and the radio base station in this way is referred to as “channel switching process”.

Hereinafter, the flow of a handover process and a channel switching process in a conventional digital mobile telephone network will be described.

FIG. 2 is a configuration diagram of a conventional digital mobile telephone network.

In the figure, 20 is a mobile terminal, 21 is a radio base station, 22 is a public digital network, 23 is a radio base station interface, 24 is an analog subscriber interface,
5 is an analog fixed telephone, 26 is a digital fixed telephone.

As shown in FIG. 2, a digital mobile telephone network is often realized using a radio base station interface 23 connected to a public digital network 22 without providing a dedicated exchange. Here, the radio base station interface 23 controls the radio base station 21 and manages subscriber information and location information of the mobile terminal 20.

FIG. 3 is a sequence diagram of a handover process in a conventional digital mobile telephone network.

For example, by transmitting and receiving radio signals between the mobile terminal 20 and the radio base station (old radio base station) 21,
When the subscriber of the mobile terminal 20 moves while the subscriber of the mobile terminal 20 is making a call with the subscriber of the digital landline telephone 26 connected to the public digital network 22, The reception level and reception quality of the radio signal transmitted from the old radio base station 21 deteriorate.

Therefore, the mobile terminal 20 is connected to the old radio base station 2
When it is detected that both the reception level and the reception quality of the radio signal transmitted from No. 1 have degraded from the reference values, the old radio base station 21 is switched to the old radio base station 21 to change the radio base station that transmits and receives the radio signal. A request signal is transmitted, and the old radio base station 21 is transmitted as a response to the channel switching request signal.
When receiving the channel switching instruction signal returned from the mobile terminal 2, the mobile terminal 2 stops transmitting and receiving the wireless signal.
The call between the subscriber 0 and the subscriber of the digital fixed telephone 26 is interrupted.

Subsequently, the mobile terminal 20 transmits the new radio base station 21 to the new radio base station 21 in order to establish a communication channel used for transmitting and receiving radio signals to and from the new radio base station (new radio base station) 21. In response, a channel establishment request signal is transmitted.

Upon receiving the channel establishment request signal transmitted from mobile terminal 20, new radio base station 21 allocates a communication channel used for transmitting and receiving a radio signal to and from mobile terminal 20, and assigns the allocated communication channel. Mobile terminal 20
, A channel assignment signal is transmitted to the mobile terminal 20.

When the mobile terminal 20 receives the channel assignment signal transmitted from the new radio base station 21, the mobile terminal 20 and the new radio base station 21 thereafter transmit and receive a synchronization burst signal to and from each other on the allocated communication channel. by doing,
Perform synchronous processing.

When synchronization is established between the mobile terminal 20 and the new radio base station 21, the mobile terminal 20 transmits to the new radio base station 21 a call setup signal indicating that the handover process is to be performed.

When the new radio base station 21 receives the call setup signal transmitted from the mobile terminal 20, the new radio base station 21
A call setting signal is transmitted to the mobile station 2 via the wireless base station interface 23.

The public digital network 22 includes a new radio base station 2
When the call setting signal transmitted from the first wireless base station 21 is received, the communication path connecting the old wireless base station 21 is disconnected because the handover process is clearly specified. The communication path is switched by newly setting the communication path between them. Thereby, the old radio base station 21 releases the communication channel used for transmitting and receiving the radio signal to and from the mobile terminal 20.

When the switching of the communication path is completed, the public digital network 22 transmits a call setting acceptance signal and a response signal to the new radio base station 21, and the call setting acceptance signal and the response signal are transmitted to the new radio base station 21. Mobile terminal 2 from radio base station 21
Since it is transmitted to 0, the mobile terminal 20 resumes the transmission / reception operation of the stopped radio signal. As a result, the subscriber of the mobile terminal 20 can resume the interrupted call with the subscriber of the digital fixed telephone 26.

The above-mentioned various signals transmitted and received between the mobile terminal 20 and the old radio base station 21 and between the mobile terminal 20 and the new radio base station are prepared separately from the communication channel. Is transmitted and received using the control channel.

Also, the old radio base station 21
In some cases, it may be necessary to transmit / receive a radio signal to / from itself again depending on the way of moving, and in consideration of such a case, a predetermined time elapses after transmitting the channel switching instruction signal. In the meantime, the transmission of the synchronization burst signal is continued to secure the communication channel used so far.

That is, when it becomes necessary for the mobile terminal 20 to transmit / receive a radio signal to / from the old radio base station 21 again, the execution of the handover process is stopped and the mobile terminal 2
0 and the old radio base station 21 can restart the transmission and reception of the radio signal after performing the synchronization process again using the same communication channel as the communication channel used so far.

In the above-described handover process, the mobile terminal 20 detects that both the reception level and the reception quality of the radio signal transmitted from the old radio base station 21 have deteriorated from the reference values. When the old radio base station 21 detects that both the reception level and the reception quality of the radio signal transmitted from the mobile terminal 20 have degraded from the reference values, the old radio base station 21 receives the channel switching request signal transmitted from the mobile terminal 20. Before, for the mobile terminal 20,
A channel switching instruction signal may be transmitted.

FIG. 4 is a sequence diagram of a channel switching process in a conventional digital mobile telephone network.

For example, by transmitting and receiving a radio signal between the mobile terminal 20 and the radio base station 21, the subscriber of the mobile terminal 20 can communicate with the subscriber of the digital fixed telephone 26 connected to the public digital network 22. When there is radio interference from a mobile terminal 20 in the vicinity during a call between the mobile terminals 20, the reception level of the radio signal transmitted from the radio base station 21 does not deteriorate in the mobile terminal 20,
Reception quality deteriorates.

Therefore, the mobile terminal 20 is connected to the radio base station 21
When it is detected that the reception quality of the radio signal transmitted from the base station has degraded from the reference value, a communication channel switching request signal is transmitted to the radio base station 21 in order to change the communication channel used for transmitting and receiving the radio signal. When the mobile terminal 2 transmits and receives the traffic channel switching instruction signal returned from the radio base station 21 as a response to the traffic channel switching request signal, the mobile terminal 2 stops transmitting and receiving the radio signal.
The call between the subscriber 0 and the subscriber of the digital fixed telephone 26 is interrupted.

Here, the changed communication channel (new communication channel) may be requested by the mobile terminal 20 by a communication channel switching request signal, or the radio base station 2
1 may be instructed by a traffic channel switching instruction signal.

Subsequently, the mobile terminal 20 and the radio base station 2
1 executes synchronization processing by mutually transmitting and receiving a synchronization burst signal on a new communication channel.

When synchronization is established between the mobile terminal 20 and the radio base station 21, the radio base station 21 uses the communication channel (former communication channel) used for transmitting and receiving radio signals to and from the mobile terminal 20. Is released, and the mobile terminal 20 restarts the transmission / reception operation of the stopped radio signal. This allows
The subscriber of the mobile terminal 20 can resume the interrupted call with the subscriber of the digital fixed telephone 26.

The above-mentioned various signals transmitted and received between the mobile terminal 20 and the radio base station 21 are transmitted and received using a control channel prepared separately from the communication channel.

In consideration of the case where the radio interference with the mobile terminal 20 is eliminated, the radio base station 21 keeps the synchronization until a predetermined time elapses after transmitting the speech channel switching instruction signal. By continuously transmitting the burst signal, the old communication channel is secured.

That is, when the radio interference with the mobile terminal 20 is eliminated, the execution of the channel switching process is stopped, and the mobile terminal 20 and the radio base station 21 communicate with the same communication channel as the one used before. After performing the synchronization process again using the channel, transmission and reception of the wireless signal can be resumed.

In the above-described channel switching process, the mobile terminal 20 detects that the reception quality of the radio signal transmitted from the radio base station 21 has deteriorated below the reference value. 21 detects that the reception quality of the radio signal transmitted from the mobile terminal 20 has deteriorated below the reference value, the mobile terminal 20 receives the communication channel switching request signal transmitted from the mobile terminal 20 before receiving the signal.
, A communication channel switching instruction signal may be transmitted to instruct a new communication channel.

As described above, in the conventional digital mobile telephone network, the mobile terminal 20 and the radio base station 2
1 respectively monitor the reception level and the reception quality of the radio signal, and when both the reception level and the reception quality are deteriorated from the reference values, the handover process is executed, and only the reception quality is set to the reference value. In the case of further deterioration, a channel switching process is executed.

In the digital mobile telephone network adopting the above-mentioned TDMA system, the frequency of occurrence of errors in data in a time slot (hereinafter referred to as "slot error rate") is used as an index of radio signal reception quality. Is generally used. That is, it is determined that the fact that the slot error rate reaches the reference value is equivalent to the fact that the reception quality of the radio signal is degraded from the reference value.

Further, as described above, in the conventional digital mobile telephone network, when the execution of the handover process or the channel switching process is started during a call, the silent state is maintained until the execution of these processes is completed. Call is interrupted. However, the subscribers who are talking (in the example described above, the subscriber of the mobile terminal 20 and the subscriber of the digital fixed telephone 26) have finished executing the handover process or the channel switching process when the silence state is released. The call can be resumed.

Further, in the conventional digital mobile telephone network, when the execution of the handover process or the channel switching process is started during a call, it is indicated that the process is in progress until the execution of these processes is completed. In some cases, a notification sound is generated. In such a case, the subscriber on the call
When the generation of the notification sound is canceled, it is possible to know that the execution of the handover process or the channel switching process has been completed, and the call can be resumed.

By the way, in this type of digital mobile telephone network, data communication can be performed not only by transmitting and receiving a digital voice signal but also by transmitting and receiving a data signal. That is, the wireless signal transmitted and received on the communication channel can be a digital signal that is digitally modulated with a data signal.

Therefore, using the digital mobile telephone network,
It is possible to construct a mobile radio data communication system for performing data communication between a data terminal connected to the mobile terminal 20 and a data terminal connected to a digital mobile telephone network via a digital wired line.

In such a mobile radio data communication system, a digital transmission path with a constant speed can be provided between two data terminals performing data communication, so that it can be conveniently used for various purposes.

However, as described above, when the execution of the handover process or the channel switching process is started during a call, the subscriber during the call is in a silent state even if the call is interrupted. Is released, it is possible to know that the execution of the handover process or the channel switching process has been completed, and the call can be resumed. However, the execution of the handover process or the channel switching process is started during data communication. In such a case, if the data communication is interrupted, the data transmitted by the data terminal on the transmission side is lost, causing a problem that erroneous data is transmitted to the data terminal on the reception side. Furthermore, before and after the execution of the handover process and the channel switching process, the data communication path is changed, so that the delay time changes and the continuity of data is often lost.

Conventionally, in data communication using a digital transmission line with a constant speed, if an error occurs in received data and a data terminal cannot receive appropriate data for a long period of time, not only will data be lost during that time, but also However, there is a possibility that the data terminal on the receiving side disconnects the data terminal because the data terminal is regarded as abnormal in the transmission path.

By the way, conventionally, in order to appropriately transmit data on a transmission path for transmitting a bit signal of a constant speed,
In many cases, data (hereinafter, referred to as “information data”) that is the content to be actually transmitted is transmitted in a predetermined format between two data terminals.

For example, when the information data always occurs in bursts instead of a fixed number of bits, a frame having a configuration as shown in FIG. 5 is formed.

In FIG. 5, reference numeral 501 denotes a frame synchronization bit for detecting the head of a frame, 502 denotes an information data length indicating the data length of information data, 503 denotes information data, and 504 denotes invalid data.

As a result, the data terminal determines the information data 50 in the received frame by the information data length 502.
3 can be identified.

For example, when detecting an error in the received data, a frame having a configuration as shown in FIG. 6 is formed.

In FIG. 6, reference numeral 601 denotes a frame synchronization bit; 602, a transmission frame number indicating the number of a frame to be transmitted; 603, a request frame number indicating a frame number for requesting retransmission to a data terminal of a communication partner;
4 is an information data length, 605 is information data, 606 is invalid data, and 607 is an error detection code such as a parity bit.

Thus, the data terminal can detect the error present in the received frame by using the error detection code 607, and furthermore, when the error is detected,
By transmitting the frame in which the frame number of the frame in which the error is detected to the request frame number 603 to the data terminal of the communication partner, it is possible to request retransmission of the frame in which the error is detected.

For example, when correcting an error in the received data, a frame having a configuration as shown in FIG. 7 is formed.

In FIG. 7, reference numeral 701 denotes a frame synchronization bit; 702, an information data length; 703, information data;
4 is invalid data, and 705 is an error correction code.

Thus, the data terminal can correct an error existing in the received frame by using the error correction code 705.

Conventionally, in order to improve transmission efficiency, information data is often compressed before transmission.

As described above, when data communication is performed by forming a frame or when data communication is performed by performing data compression, once data continuity is lost, the data terminal on the receiving side is lost. However, there is a problem in that information data cannot be correctly extracted from a data signal to be received next, and it is necessary to restart frame synchronization processing and compression processing from the beginning.

In order to solve such problems, conventionally, in a mobile radio data communication system, a mobile terminal executes a handover process or a channel switching process for a data terminal connected thereto. The base station controller provided for notifying the start and the end and controlling the plurality of wireless base stations is provided to a data terminal connected to a digital wireless telephone network via a digital wired line. A technique has been devised that enables these data terminals to execute appropriate processing by notifying that the execution of the handover processing and the channel switching processing has been started and ended.

Hereinafter, this technique will be described with reference to FIG.

FIG. 8 is a configuration diagram of a mobile radio data communication system according to the prior art.

In the figure, 80 is a mobile terminal, 81 and 82 are radio base stations, 83 is a base station controller, 84 and 85 are data terminals, and 86 and 87 are data communication processing units built in the data terminals 84 and 85. And 88, a data terminal control unit built in the mobile terminal 80, 89, a data terminal control unit built in the base station controller 83, and 90, a public digital network.

In FIG. 8, the base station controller 8
3 corresponds to the wireless base station interface 23 described above.

As shown in FIG. 8, in a conventional mobile radio data communication system, a dedicated signal line 91 connecting between a radio base station 81 and a base station controller 83 is connected to a radio base station 81. It has a structure having a communication channel and a control channel, like the wireless section between them.

Then, the radio base station 81 informs the base station control device 8 using the control channel on the dedicated signal line 91 that the execution of the handover process or the channel switching process has been started.
3, and that the execution of the handover process or the channel switching process has been completed can be reported to the base station controller 83 using the control channel in the dedicated signal line 91.

On the other hand, as shown in FIG. 8, in a conventional mobile radio data communication system, a digital wired line (including a public digital network 90) connecting between a base station controller 83 and a data terminal 85 is included. ) Also dedicated signal line 9
As in the case of No. 1, the structure has a communication channel and a control channel.

Then, the base station control device 83 informs that the execution of the handover process or the channel switching process has been started.
A notification is made to the data terminal 85 using the control channel in the digital wired line, and the fact that the execution of the handover process or the channel switching process is completed can be reported to the data terminal 85 using the control channel in the digital wired line. .

For example, in FIG. 8, when data communication is performed between a data terminal 84 connected to a mobile terminal 80 and a data terminal 85 connected to a digital mobile telephone network via a digital wired line. When the reception level and the reception quality of the radio signal transmitted and received between the mobile terminal 80 and the radio base station 81 are both deteriorated from the reference value and the handover process is executed, the mobile terminal 80 The terminal control unit 88 notifies the data terminal 84 that the execution of the handover process has been started by transmitting a handover occurrence signal using the control channel.

The radio base station 81 is connected to a dedicated signal line 91.
By transmitting a handover occurrence signal using the inside control channel, the base station controller 83 is notified that the execution of the handover process has been started.

In base station controller 83, upon receiving the handover occurrence signal transmitted from radio base station 81, data terminal control section 89 transmits the handover occurrence signal using the control channel in the digital wired line. This notifies the data terminal 85 that the execution of the handover process has been started.

Therefore, in the data terminals 84 and 85, the data communication processing units 86 and 87 respectively
0, upon receiving the handover occurrence signal transmitted from the base station controller 83, to prevent loss of information data,
Data transmission / reception operation can be stopped, and further, in order to deal with discontinuity of data, procedures such as frame synchronization processing are temporarily terminated, and preparations can be made so as to be able to take immediate action when the transmission path is recovered. become able to.

In order to prevent the occurrence of a large number of errors in the received data, a handover occurrence signal is transmitted even when the handover process or the channel switching process is not executed, as in the case where the handover process or the channel switching process is executed. Japanese Patent Application Laid-Open No. 6-141025 discloses a method for stopping the data transmission / reception operation of the data terminal.

[0069]

In the above-mentioned conventional mobile radio data communication system, the digital wired line starts executing a handover process and a channel switching process in addition to a communication channel used for transmitting and receiving a data signal. In order to notify that the operation has been completed and the operation has been completed, it is necessary to have a structure having a control channel used for transmitting and receiving a handover occurrence signal, but the existing digital wired line does not have such a control channel. In many cases, existing data terminals connected to a digital mobile telephone network via a digital wired line must be notified to the effect that handover processing and channel switching processing have started and ended. All of the digital wired lines need to be modified.

In order to notify the data terminal connected to the mobile terminal that the execution of the handover process and the channel switching process has been started and ended, the mobile terminal has a built-in data terminal control unit. Therefore, the software of the existing mobile terminal needs to be significantly modified.

Accordingly, a first object of the present invention is to provide a digital mobile telephone network having a plurality of mobile terminals and a plurality of radio base stations, and a data terminal connected to the mobile terminal and a digital mobile telephone network. In a mobile wireless data communication system that performs data communication with a data terminal connected via a digital wired line to a mobile wireless data communication system, there is no need to remodel all of the existing digital wired lines or significantly modify the software of the mobile terminal. Another object of the present invention is to enable these data terminals to stop the data transmission / reception operation when the execution of the handover process or the channel switching process is started.

Further, a second object of the present invention is to achieve the first object and further connect a data terminal connected to a mobile terminal and a digital mobile telephone network via a digital wired line. It is to enable the data terminal to resume the data transmission / reception operation when the execution of the handover process or the channel switching process ends.

[0073]

In order to achieve the first object, the present invention provides, as a first aspect, a method of allocating a plurality of mobile terminals and assigning the mobile terminals to the plurality of mobile terminals. A first data terminal connected to the mobile terminal and a digital cable connected to the digital mobile phone network using a digital mobile phone network having a plurality of radio base stations for transmitting and receiving radio signals using the communication channel. In a mobile radio data communication system for performing data communication with a second data terminal connected via a line, the mobile terminal and the first data terminal, and between the digital wired line and the second A communication adapter device is provided between the two data terminals and establishes a data communication link on a communication path between the two data terminals.

Here, in the digital mobile telephone network, the mobile terminal and the radio base station naturally perform the above-mentioned handover processing and channel processing when the reception quality of the radio signal is degraded from the reference value. One of the switching processes is executed.

The mobile terminal is connected to the communication adapter device interposed between the mobile terminal and the first data terminal from the start of execution of any of the handover process and the channel switching process to the end thereof. On the other hand, instead of the data received as a radio signal from the radio base station,
The wireless base station includes a pattern data transmitting unit that repeatedly transmits pattern data composed of a predetermined data pattern, wherein the radio base station performs execution of any one of a handover process and a channel switching process until the process ends. A pattern data transmitting unit for repeatedly transmitting the pattern data instead of data received as a radio signal from the mobile terminal to a communication adapter device interposed between the second data terminal and A communication adapter device configured to determine whether data received from the mobile terminal or data received from the wireless base station via the digital wired line is the pattern data; When the means detects the above pattern data, the handover process or the channel A determining means for determining that the execution of the switching process has been started, and, when the determining means determines that the execution of the handover process or the channel switching process has been started, the first data terminal or the second data terminal transmits the data to the first data terminal or the second data terminal. And a data terminal control means for stopping the transmission / reception operation.

According to the first aspect, when the communication adapter apparatus detects the pattern data transmitted from the mobile terminal or the radio base station, execution of a handover process or a channel switching process is started. To the first data terminal and the second data terminal.
Data terminal can stop the data transmission / reception operation.

In the digital mobile telephone network, the mobile terminal and the radio base station communicate with each other within a predetermined time after the start of the execution of the handover process or the channel switching process, as described above. Generally, the execution of the started handover process or the channel switching process is stopped when the signal reception quality is improved to the reference value or more.

Therefore, in order to achieve the second object, according to a second aspect of the present invention, in the first aspect, the determination means starts executing a handover process or a channel switching process. If the pattern data detection means detects data other than the pattern data before the same time as the predetermined time elapses after the determination, it is determined that the execution of the handover process or the channel switching process has been stopped. The data terminal control means causes the first data terminal or the second data terminal to resume the data transmission / reception operation when the determination means determines that the execution of the handover process or the channel switching process has been stopped. Further, when the determination means determines that the execution of the handover process or the channel switching process has not been stopped, Then, the data communication link is re-established on the communication path with the other communication adapter device, and if the data communication link is successfully set, the data is transmitted to the first data terminal or the second data terminal. The transmission / reception operation is restarted.

According to the second aspect, the communication adapter device performs a handover process or a handover process when the predetermined time has elapsed since the detection of the pattern data transmitted from the mobile terminal or the radio base station. Since it is possible to know that the execution of the channel switching process has not been stopped, the data communication link is set again on a new communication path with the other communication adapter device, and the data communication link is set. Is successful, it is possible to know that the execution of the handover process or the channel switching process has been completed, so that the first data terminal and the second data terminal can restart the data transmission / reception operation.

Further, according to the second aspect, the communication adapter device detects the pattern data transmitted from the mobile terminal or the radio base station before the predetermined time elapses. When data other than the pattern data transmitted from the mobile terminal or the radio base station is detected, it is possible to know that the execution of the handover process or the channel switching process has been stopped. The first data terminal and the second data terminal can resume the data transmission / reception operation with the data communication link already set on the original communication path between the first data terminal and the second data terminal.

The present invention can achieve the first and second objects even when the digital mobile telephone network adopts the TDMA system.

When the digital mobile telephone network adopts the TDMA system, the mobile terminal and the radio base station use the time slot allocated to the mobile terminal to make an error in data received as a radio signal. When the frequency of occurrence reaches the reference value, one of the handover process and the channel switching process is executed.

Therefore, the digital mobile telephone network is TD
When the MA system is adopted, as a third aspect, in the above-described first aspect and second aspect, the pattern data transmitting means of the mobile terminal uses the time slot to transmit the radio signal. When an error occurs in data received as a radio signal from the base station, the first
For the communication adapter device interposed between the mobile terminal and the data terminal, the pattern data is transmitted instead of the data, and the pattern data transmitting means of the radio base station transmits the pattern data from the mobile terminal using the time slot. If an error has occurred in data received as a radio signal, the second
For the communication adapter device interposed between the data terminal and the data terminal, instead of the data, transmitting the pattern data, the determining means, not when the pattern data detecting means detects the pattern data, When the frequency at which the pattern data detecting means detects the pattern data reaches the same reference value as the reference value, it can be determined that the execution of the handover process or the channel switching process has been started.

According to a third aspect, the communication adapter apparatus performs a handover process or a channel operation when the frequency of detecting the pattern data transmitted from the mobile terminal or the radio base station reaches the reference value. Since it is possible to know that the execution of the switching process has been started, the first data terminal and the second data terminal can stop the data transmission / reception operation.

In the above-described fourth aspect, the determining means may determine whether the frequency at which the pattern data detecting means has detected the pattern data does not reach the same reference value as the reference value. May determine that the execution of the handover process or the channel switching process has been started when the number of times the pattern data is continuously detected reaches a predetermined number.

[0086]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the mobile radio data communication system according to the present invention will be described below with reference to the drawings.

The mobile radio data communication system of the present invention
A data terminal implemented using a digital mobile telephone network having a plurality of mobile terminals and a plurality of radio base stations and connected to the mobile terminal, and a data terminal connected to the digital mobile telephone network via a digital wired line Data communication is performed between the server and the server.

FIG. 1 is a configuration diagram of the mobile radio data communication system of the first embodiment.

In the figure, 10 is a mobile terminal, 11 and 12 are radio base stations, 13 is a radio base station interface, 14 is a public digital network, 15 is a digital fixed telephone, and 16 and 1
7 is a data terminal, and 18 and 19 are communication adapter devices.

As shown in FIG. 1, in the mobile radio data communication system of the first embodiment, when the data terminal 16 is connected to the mobile terminal 10, a communication adapter device 18 is interposed. When the terminal 17 is connected to a digital mobile telephone network via a digital wired line, a communication adapter device 19 is interposed.

In the mobile radio data communication system according to the first embodiment, as will be described later in detail, the mobile terminal 10 and the radio base stations 11 and 12 perform either the handover process or the channel switching process. From the start to the end of the execution, pattern data consisting of a predetermined data pattern is repeatedly transmitted, and the communication adapter devices 18 and 19 detect the transmitted pattern data to perform a handover process or a channel. Communication adapter devices 18 and 1 indicate that the execution of the switching process has been started.
9 so that they can know.

Accordingly, in the mobile radio data communication system according to the first embodiment, the dedicated signal line 1 connecting the radio base station 11 and the radio base station interface 13 is connected.
Reference numeral 00 may be a structure having only a communication channel, and does not need to be modified as in the prior art mobile wireless data communication system while maintaining an existing signal line (that is, a digital wired line). In addition, the wireless base station interface 1
The digital wired line (including the public digital network 14) connecting between the terminal 3 and the data terminal 17 may have a structure having only a communication channel. No modification is required as in the data communication system.

The data terminal 17 may be connected to the digital fixed telephone 15 via the communication adapter 19.

FIG. 9 is a block diagram showing the configuration of the radio base station 11 and the communication adapter device 19.

In the figure, reference numeral 900 denotes a line control unit;
2 is a buffer, 903 is a wireless signal transmission unit, 904 is a wireless signal reception unit, 905 is a pattern data generation unit, 906 is a reception level / reception quality determination unit, 907 is a timer, 908
Is a control unit for controlling the entire wireless base station 11, 909 is a line control unit, 910 is a pattern data detection unit, 911 is a data terminal control unit, 912 is a timer, and 913 is a control unit for controlling the entire communication adapter device 19. .

The configuration of the radio base station 12 is the same as the configuration of the radio base station 11, and the configuration of the communication adapter device 18 is also the same as the configuration of the communication adapter device 19.

The configuration of mobile terminal 10 is the same as that of radio base station 11, except that line control section 900 and buffers 901 and 902 do not exist, and the subscriber provided in mobile terminal 10 Operation part of (for example,
Keypad and display).

First, the operation of each block of the radio base station 11 will be described.

In the radio base station 11, the line control unit 90
0 receives data transmitted from the digital wired line (that is, data transmitted by the data terminal 17) and stores the received data in the buffer 901. The wireless signal transmission unit 903 reads data stored in the buffer 903, modulates the read data, and transmits the modulated data to the mobile terminal 10.

In radio base station 11, radio signal receiving section 904 receives data transmitted from mobile terminal 10 as a radio signal (ie, data transmitted by data terminal 16) and demodulates the received data. Buffer 9
02 is stored. The line control unit 900 includes a buffer 902
Read the data stored in the
The data is sequentially transmitted to a digital wired line.

On the other hand, reception level / reception quality judgment section 906
Determines whether the reception level and the reception quality of the data received by the radio signal receiving unit 904 are degraded from the reference values, and notifies the control unit 908 of the determination result.

Control unit 908 starts execution of handover processing and receives a pattern when reception level / reception quality determination unit 905 notifies that both the reception level and the reception quality have degraded from the reference values. The pattern data generator 905 is controlled so that data is generated and stored in the buffer 902.

If the reception level has not deteriorated from the reference value, but the reception level / reception quality determination unit 905 notifies that the reception quality has deteriorated from the reference value, At the same time as the execution of the channel switching process is started, the pattern data generation unit 905 is controlled so that pattern data is generated and stored in the buffer 902.

Therefore, line control section 900 transmits the pattern data stored in buffer 902 by pattern data generating section 905 to the digital wired line instead of the data received and demodulated by radio signal receiving section 904. .

Thus, when the execution of the handover process or the channel switching process is started, the radio base station 1
1 transmits the pattern data to the communication adapter device 19, and similarly, when the execution of the handover process or the channel switching process is started,
The pattern data is transmitted from the mobile terminal 10 to the communication adapter device 18.

When performing the handover process or the channel switching process, the mobile station 1
The various control signals transmitted to 0 are generated by the control unit 908, modulated by the wireless signal transmission unit 903, and transmitted. Further, when executing the handover process or the channel switching process, the mobile terminal 10 transmits the radio base station 11
Are received and demodulated by the wireless signal receiving unit 904 and notified to the control unit 908.

When the execution of the handover process or the channel switching process is started, the control unit 908 performs a predetermined time (execution of the handover process and the channel switching process) in consideration of the case where the execution of the handover process and the channel switching process is stopped. It is necessary to set the time to be shorter than the time required for.).

If the reception level / reception quality determination unit 905 notifies the reception level and the reception quality that both have reached the reference values before the timer 907 times out, the control unit 908 performs a handover. The pattern data generation unit 9 stops the execution of the process or the channel switching process and stops the generation of the pattern data.
05 is controlled.

When the timer 907 times out, the control unit 908 controls the pattern data generation unit 905 so as to stop the generation of the pattern data when the execution of the handover process or the channel switching process ends. .

More specifically, the control unit 908 includes a timer 907
If the process that started execution is a handover process when timeout occurs, a new communication path between the wireless base station (for example, the wireless base station 12) to be changed and the public digital network 14 is set. When the communication path between the wireless base station 11 and the public digital network 14 is disconnected, the control unit 908 of the mobile terminal 10 transmits and receives a wireless signal between the mobile terminal 10 and the wireless base station 11. The pattern data generating unit 905 stops generating the pattern data when the communication channel used for the communication is released.
Control.

More specifically, when timer 907 times out, if the process started to be executed is a channel switching process, control unit 908 assigns a new communication channel to mobile terminal 10 and transmits a new radio channel to radio base station. When the communication channel used for transmitting and receiving the radio signal between the station 11 and the mobile terminal 10 is released, the pattern data generation unit 905 is controlled so as to stop generating the pattern data.

Thus, when the execution of the handover process or the channel switching process is stopped, and when the execution of the handover process or the channel switching process is completed, the transmission of the pattern data from the radio base station 11 to the communication adapter device 19 is performed. Is stopped, and similarly, when the execution of the handover process or the channel switching process is stopped, and when the execution of the handover process or the channel switching process ends, the mobile terminal 1
From 0, the transmission of the pattern data to the communication adapter device 18 is stopped.

Next, the operation of each block of the communication adapter device 19 will be described.

In the communication adapter device 19, the data terminal control section 911 receives the data transmitted from the data terminal 17, and the line control section 909 transmits the data terminal control section 9
11 transmits the received data to a digital wired line.

In the communication adapter device 19, the line control unit 909 stores the data transmitted from the digital wired line (ie, the data transmitted by the data terminal 16).
And the data terminal control unit 911 sends the
9 transmits the received data to the data terminal 17.

Note that the line control unit 909 includes a control unit 913
With this control, at the start of data communication, a data communication link is set on the communication path between the communication adapter devices 18 and 19 with the line control unit 909 of the communication adapter device 18.

On the other hand, the pattern data detecting section 910 checks whether or not the data received by the line control section 909 is pattern data, and if the data is pattern data, notifies the control section 913 of the fact.

When the control unit 913 is notified from the pattern data detection unit 910 that the pattern data has been detected,
It determines that the execution of the handover process or the channel switching process has been started, and controls the data terminal control unit 911 so that the data terminal 17 stops the data transmission / reception operation.

As a result, when the execution of the handover process or the channel switching process is started, the communication adapter device 19 causes the data terminal 17 to stop the data transmission / reception operation.
Means that the data terminal 16 stops the data transmission / reception operation when the execution of the handover process or the channel switching process is started.

When the control unit 913 determines that the execution of the handover process or the channel switching process has been started, the control unit 913 starts the measurement by the timer 912 and notifies the control unit 913 of the inspection result. Control. When the timer 912 measures the same time as the time measured by the timer 907 of the radio base station 11 (a predetermined time in consideration of the case where the execution of the handover process and the channel switching process is stopped), the timer 912 times out. ing.

If the pattern data detection unit 910 notifies that data other than the pattern data has been detected before the timer 912 times out, the control unit 913 executes the handover process or the channel switching process. The data terminal controller 911 determines that the data terminal 17 has been stopped, and causes the data terminal 17 to resume the data transmission / reception operation.
Control.

Thus, when the execution of the handover process or the channel switching process is stopped, the communication adapter device 19 causes the data terminal 17 to resume the data transmission / reception operation.
Means that when the execution of the handover process or the channel switching process is stopped, the data terminal 16 restarts the data transmission / reception operation.

When the timer 912 times out, the control unit 913 determines that the execution of the handover process or the channel switching process has not been stopped, and performs data communication on a new communication path between the communication adapter devices 18 and 19. The line control unit 909 is controlled so as to set the link again. Then, when the line control unit 909 successfully sets the data communication link, the control unit 913 determines that the execution of the handover process or the channel switching process has been completed, and causes the data terminal 17 to restart the data transmission / reception operation. The controller 911 is controlled.

As a result, when the execution of the handover process or the channel switching process is completed, the communication adapter device 19 causes the data terminal 17 to resume the data transmission / reception operation.
Means that the data terminal 16 restarts the data transmission / reception operation when the execution of the handover process or the channel switching process ends.

If the data transmitted from the data terminal 17 has the same value as the pattern data, the data terminal control section 911 transmits the pattern data of the communication adapter device 18 if the line control section 909 transmits the data as it is. Since the data is detected by the data detection unit 910, it is preferable to convert the data to a close value different from the original value.

Next, the flow of the handover process and the channel switching process in the first embodiment will be described.

FIG. 10 is a sequence diagram of the handover process in the first embodiment.

For example, by transmitting and receiving a radio signal between the mobile terminal 10 and the radio base station (old radio base station) 11,
When performing data communication between the data terminal 16 connected to the mobile terminal 10 via the communication adapter device 18 and the data terminal 17 connected to the public digital network 14 via the communication adapter device 19, When the subscriber of the mobile terminal 10 moves, the reception level and reception quality of the radio signal transmitted from the old radio base station 11 deteriorate in the mobile terminal 10.

Therefore, the mobile terminal 10 communicates with the old radio base station 1.
When it is detected that both the reception level and the reception quality of the radio signal transmitted from No. 1 have degraded from the reference values, the old radio base station 11 is switched to the channel to change the radio base station that transmits and receives the radio signal. When transmitting the request signal and receiving the channel switching request signal transmitted from the mobile terminal 10, the old radio base station 11 transmits a channel switching instruction signal to the mobile terminal 10.

As a result, the execution of the handover process is started. In the first embodiment, when the execution of the handover process is started, the mobile terminal 10 transmits the pattern data to the communication adapter 18. The old wireless base station 11 repeatedly transmits the pattern data to the communication adapter device 19 via the digital wired line.

When mobile terminal 10 receives the channel switching instruction signal returned from old radio base station 11 as a response to the channel switching request signal, mobile terminal 10 stops transmitting and receiving radio signals.

According to the prior art, when the execution of the handover process is started, the data communication that has been performed so far in the communication path between the mobile terminal 10 and the old radio base station 11 is interrupted, According to the first embodiment, the communication adapter devices 18 and 19 detect the pattern data transmitted from the mobile terminal 10 and the old radio base station 11 according to the first embodiment. ,
Since it is determined that the execution of the handover process or the channel switching process has been started and the data transmission / reception operations of the data terminals 16 and 17 are stopped, the above-described problem does not occur.

Subsequently, the mobile terminal 10 transmits the new radio base station 12 to the new radio base station 12 in order to establish a communication channel used for transmitting and receiving radio signals to and from the new radio base station (new radio base station) 12. In response, a channel establishment request signal is transmitted.

Upon receiving the channel establishment request signal transmitted from mobile terminal 10, new radio base station 12 allocates a communication channel used for transmitting and receiving a radio signal to and from mobile terminal 10, and assigns the allocated communication channel. Mobile terminal 10
, A channel assignment signal is transmitted to the mobile terminal 10.

When the mobile terminal 10 receives the channel assignment signal transmitted from the new radio base station 12, the mobile terminal 10 and the new radio base station 12 thereafter transmit and receive a synchronization burst signal to and from each other on the allocated traffic channel. by doing,
Perform synchronous processing.

When synchronization is established between the mobile terminal 10 and the new radio base station 12, the mobile terminal 10 transmits to the new radio base station 12 a call setting signal indicating that handover processing is to be performed.

Upon receiving the call setup signal transmitted from mobile terminal 10, new radio base station 12 makes public digital network 1
4, a call setting signal is transmitted via the wireless base station interface 13.

The public digital network 14 is connected to the new radio base station 1
When the call setting signal transmitted from the second wireless base station 12 is received, the communication path connecting the old wireless base station 11 and the new wireless base station 12 The communication path is switched by newly setting the communication path between them. Note that the public digital network 14 transmits a disconnection signal to the old wireless base station 11 in order to disconnect the communication path with the old wireless base station 11.

Therefore, when the old radio base station 11 receives the disconnection signal transmitted from the public digital network 14, it releases the communication channel used for transmitting and receiving the radio signal to and from the mobile terminal 10. In addition, the old radio base station 11
Is used to release the communication channel used to transmit and receive radio signals to and from the mobile terminal 10.
For 0, a release signal is transmitted.

In the first embodiment, when the communication channel is released, the old radio base station 11 stops transmitting the pattern data to the communication adapter 19, and the mobile terminal 10 transmits the pattern data to the communication adapter 18. Data transmission will be stopped.

On the other hand, when the switching of the communication channel is completed, the public digital network 14 transmits a call setting acceptance signal and a response signal to the new radio base station 12, and the call setting acceptance signal and the response signal are transmitted to the new radio base station 12. Mobile terminal 1 from radio base station 12
Since it is transmitted to 0, the mobile terminal 10 restarts the transmission / reception operation of the stopped radio signal. Thus, in the new communication path between the mobile terminal 10 and the new radio base station 12, if the data terminals 16 and 17 resume the data transmission / reception operation, the interrupted data communication can be resumed. .

By the way, in the first embodiment, when the communication adapter devices 18 and 19 determine that the execution of the handover process or the channel switching process has been started, the measurement by the timer 712 is started. When the timer 712 measures a predetermined time in consideration of the case where the execution of the handover process and the channel switching process is stopped, the timer 712 times out.
When the timer 712 that has started the measurement times out, the communication adapter devices 18 and 19 determine that the execution of the handover process or the channel switching process has not been stopped.

If the communication adapter devices 18 and 19 determine that the execution of the handover process or the channel switching process has not been stopped, the data communication link is re-established on a new communication path with the other communication adapter device. Therefore, the execution of the setting process is started. The setting process is
Even if the execution is started, the execution of the handover process is actually ended until the data communication can be resumed on the new communication path between the mobile terminal 10 and the new radio base station 12. A data communication link cannot be set on a communication path between the communication adapter devices 18 and 19.

Therefore, the communication adapter devices 18 and 19
When the setting process succeeds in setting the data communication link,
It is determined that the execution of the handover process or the channel switching process has been completed, and the data transmission / reception operation of the data terminals 16 and 17 is restarted.

Therefore, according to the first embodiment, even when the handover process is executed during the data communication between the data terminals 16 and 17, the communication adapter devices 18 and 19 perform the handover process. When the execution is started, the data transmission / reception operation of the data terminals 16 and 17 is stopped, and when the execution of the handover process is completed, the data transmission / reception operation of the data terminals 16 and 17 is restarted. Communication can be continued smoothly.

[0146] In the above-described handover processing, between the mobile terminal 10 and the old radio base station 11, and
The above-described various signals transmitted and received between the mobile terminal 10 and the new radio base station 12 are transmitted and received using a control channel prepared separately from the communication channel.

Also, the old radio base station 11
In some cases, it may be necessary to transmit and receive a radio signal to / from itself again depending on the way in which the mobile station moves, and in consideration of such a case, a predetermined time after transmitting the channel switching instruction signal is set to the timer 907. Timer 907
Until the time-out occurs, the transmission of the synchronous burst signal is continued so that the communication channel used up to that time is secured. Note that the time measured by the timer 907 corresponds to the time measured by the timer 912 of the communication adapter devices 18 and 19.

That is, when it is necessary for the mobile terminal 10 to transmit and receive a radio signal to and from the old radio base station 11 again and the execution of the handover process is stopped, the mobile terminal 1
0 and the old wireless base station 11 can restart the transmission and reception of the wireless signal after performing the synchronization process again using the communication channel used so far.

In the first embodiment, when the execution of the handover process is stopped, the mobile terminal 10 and the old radio base station 11 stop transmitting the pattern data to the communication adapter devices 18 and 19. Become.

Therefore, in the first embodiment, the pattern data is transmitted from the mobile terminal 10 and the old radio base station 11 to the communication adapter devices 18 and 19 before the timer 912 of the communication adapter devices 18 and 19 times out. Are transmitted, the communication adapter devices 18 and 19 determine that the execution of the handover process or the channel switching process has been stopped, and the data terminal 1
The data transmission / reception operations 6 and 17 are restarted.
When it is determined that the execution of the handover process or the channel switching process has been stopped, the communication adapter devices 18 and 19 do not need to execute the above-described setting process.

Therefore, according to the first embodiment, even if the handover process started to be executed during the data communication between the data terminals 16 and 17 is stopped,
Since the communication adapter devices 18 and 19 resume the data transmission and reception operations of the data terminals 16 and 17 when the execution of the handover process is stopped, the data communication can be smoothly continued. .

In the above-mentioned handover process, the mobile terminal 10 detects that both the reception level and the reception quality of the radio signal transmitted from the old radio base station 11 have deteriorated from the reference value. When the old radio base station 11 detects that both the reception level and the reception quality of the radio signal transmitted from the mobile terminal 10 have degraded from the reference values, the old radio base station 11 receives the channel switching request signal transmitted from the mobile terminal 10. Before, for the mobile terminal 10,
A channel switching instruction signal may be transmitted.

FIG. 11 is a sequence diagram of the channel switching processing in the first embodiment.

For example, by transmitting and receiving a radio signal between the mobile terminal 10 and the radio base station 11, the data terminal 16 connected to the mobile terminal 10 via the communication adapter device 18 is transmitted.
And the public digital network 1 via the communication adapter device 19.
During data communication with the data terminal 17 connected to the communication terminal 4, if there is radio interference from the mobile terminal 10 in the vicinity, the mobile terminal 10
Although the reception level of the radio signal transmitted from the PC does not deteriorate, the reception quality deteriorates.

Therefore, the mobile terminal 10 is connected to the radio base station 11
When it is detected that the reception quality of the radio signal transmitted from the base station has deteriorated below the reference value, a communication channel switching request signal is sent to the radio base station 11 in order to change the communication channel used for transmitting and receiving the radio signal. Upon transmitting, upon receiving the traffic channel switching request signal transmitted from the mobile terminal 10, the radio base station 11 transmits a traffic channel switching instruction signal to the mobile terminal 10.

As a result, the execution of the channel switching process is started. In the first embodiment, when the execution of the channel switching process is started, the mobile terminal 10 sends a pattern to the communication adapter device 18. The data is repeatedly transmitted, and the wireless base station 11 repeatedly transmits the pattern data to the communication adapter device 19 via the digital wired line.

When mobile terminal 10 receives the communication channel switching instruction signal returned from radio base station 11 as a response to the communication channel switching request signal, mobile terminal 10 stops transmitting and receiving radio signals.

Here, the changed communication channel (new communication channel) may be requested by the mobile terminal 10 using a communication channel switching request signal, or the radio base station 1
1 may be instructed by a traffic channel switching instruction signal.

According to the prior art, when the execution of the channel switching process is started, the data communication that has been performed on the communication path between the mobile terminal 10 and the radio base station 11 is interrupted. According to the first embodiment, the communication adapter devices 18 and 19 are connected to the mobile terminal 10 and the radio base station 11 according to the first embodiment.
By detecting the pattern data transmitted from the terminal, it is determined that the execution of the handover process or the channel switching process has been started, and the data transmission and reception operations of the data terminals 16 and 17 are stopped. Will not occur.

Subsequently, the mobile terminal 10 and the radio base station 1
1 executes synchronization processing by mutually transmitting and receiving a synchronization burst signal on a new communication channel.

When synchronization is established between the mobile terminal 10 and the radio base station 11, the radio base station 11 uses the communication channel (old communication channel) used for transmitting and receiving radio signals to and from the mobile terminal 10. Is released, and the mobile terminal 10 restarts the transmission / reception operation of the stopped radio signal. This allows
If the data terminals 16 and 17 resume the data transmission / reception operation on the communication path using the new communication channel between the mobile terminal 10 and the radio base station 11, the suspended data communication can be resumed.

[0162] The radio base station 11 transmits a release signal to the mobile terminal 10 in order to release the old communication channel used for transmitting and receiving radio signals to and from the mobile terminal 10. It has become.

In the first embodiment, when the old communication channel is released, the radio base station 11 stops transmitting the pattern data to the communication adapter 19, and the mobile terminal 10 transmits the pattern data to the communication adapter 18. Data transmission will be stopped.

In the first embodiment, when the communication adapter devices 18 and 19 determine that the execution of the handover process or the channel switching process has been started, the measurement by the timer 712 is started. When the timer 712 measures a predetermined time in consideration of the case where the execution of the handover process and the channel switching process is stopped, the timer 712 times out.
When the timer 712 that has started the measurement times out, the communication adapter devices 18 and 19 determine that the execution of the handover process or the channel switching process has not been stopped.

If the communication adapter devices 18 and 19 determine that the execution of the handover process or the channel switching process has not been canceled, the communication adapter devices 18 and 19 reset the data communication link on a new communication path with the other communication adapter device. Then, execution of the setting process is started. Note that, even if the setting process is started, the execution of the channel switching process is actually ended, and the data is set on a new communication channel between the mobile terminal 10 and the radio base station 11 using a new communication channel. Until the communication can be resumed, the communication adapter devices 18, 1
No data communication link can be set up on the communication path between the nine communication paths.

Therefore, the communication adapter devices 18 and 19
When the setting process succeeds in setting the data communication link,
It is determined that the execution of the handover process or the channel switching process has been completed, and the data transmission / reception operation of the data terminals 16 and 17 is restarted.

Therefore, according to the first embodiment, even when the channel switching process is executed during the data communication between the data terminals 16 and 17, the communication adapter devices 18 and 19 perform the channel switching. When the execution of the processing is started, the data transmission / reception operations of the data terminals 16 and 17 are stopped, and when the execution of the channel switching processing is completed, the data transmission / reception operations of the data terminals 16 and 17 are restarted. Therefore, data communication can be smoothly continued.

In the above-described channel switching process, the above-mentioned various signals transmitted and received between the mobile terminal 10 and the radio base station 11 are transmitted and received using a control channel prepared separately from the communication channel. Things.

Further, in consideration of the case where radio interference to mobile terminal 10 is eliminated, radio base station 11 sets timer 907 after transmitting the communication channel switching instruction signal for a predetermined time.
Until the timer 907 times out, the transmission of the synchronous burst signal is continued to secure the old communication channel. Note that the time measured by the timer 907 is the communication adapter device 18, 1
9 corresponds to the time measured by the timer 912.

That is, when the radio interference with the mobile terminal 10 is resolved and the execution of the channel switching process is stopped, the mobile terminal 10 and the radio base station 11 use the communication channel used so far. After performing the synchronization process again, transmission and reception of the wireless signal can be resumed.

In the first embodiment, when the execution of the channel switching process is stopped, the mobile terminal 10 and the radio base station 11 stop transmitting the pattern data to the communication adapter devices 18 and 19. Become.

Therefore, in the first embodiment, before the timer 912 of the communication adapter devices 18 and 19 times out, the mobile terminal 10 and the radio base station 11 transmit the data other than the pattern data to the communication adapter devices 18 and 19. Is transmitted, the communication adapter devices 18 and 19 determine that the execution of the handover process or the channel switching process has been stopped, and the data terminal 1
The data transmission / reception operations 6 and 17 are restarted.
When it is determined that the execution of the handover process or the channel switching process has been stopped, the communication adapter devices 18 and 19 do not need to execute the above-described setting process.

Therefore, according to the first embodiment, even if the channel switching process started during data communication between the data terminals 16 and 17 is stopped,
Since the communication adapter devices 18 and 19 resume the data transmission and reception operations of the data terminals 16 and 17 when the execution of the channel switching process is stopped, the data communication can be smoothly continued. Become.

In the above-described channel switching process, the mobile terminal 10 detects that the reception quality of the radio signal transmitted from the radio base station 11 has deteriorated from the reference value. 11 detects that the reception quality of the radio signal transmitted from the mobile terminal 10 has degraded from a reference value, before the mobile terminal 10 receives the call channel switching request signal transmitted from the mobile terminal 10.
, A communication channel switching instruction signal may be transmitted to instruct a new communication channel.

In the first embodiment, the communication adapter devices 18 and 19 specify which process has been started only by knowing that the execution of the handover process or the channel switching process has been started. However, if the pattern data transmitted at the time of executing the handover process and the pattern data transmitted at the time of executing the channel switching process have different values, the communication adapter device 1
8, 19 can specify whether the execution of the handover process has been started or the execution of the channel switching process has been started.

The first embodiment described above can also be realized when the digital mobile telephone network employs the TDMA system.

Further, when the digital mobile telephone network adopts the TDMA system, the second embodiment described below can be realized.

The configuration diagram of the mobile radio data communication system of the second embodiment is the same as that of FIG.

That is, also in the mobile radio data communication system of the second embodiment, similar to the first embodiment,
When the data terminal 16 is connected to the mobile terminal 10, a communication adapter device 18 is interposed. When the data terminal 17 is connected to a digital mobile telephone network via a digital wired line, the communication adapter device 19 is connected. I try to intervene.

However, in a digital mobile telephone network adopting the TDMA system, the frequency of occurrence of errors in data in time slots (hereinafter referred to as “slot errors”) as an index of radio signal reception quality. In general, the mobile terminal 10 and the radio base stations 11 and 12 assume that when the slot error rate has reached the reference value, the reception quality of the radio signal has deteriorated from the reference value. I am to judge. That is, in the digital mobile telephone network adopting the TDMA system, the mobile terminal 10 and the radio base stations 11 and 12 each monitor the reception level of the radio signal and calculate the slot error rate. If the reception level is lower than the reference value and the slot error rate reaches the reference value,
When the handover process is executed and the slot error rate reaches the reference value, the channel switching process is executed.

Therefore, in the mobile radio data communication system of the second embodiment, the mobile terminal 10 and the radio base stations 11 and 12 are connected to the mobile terminal 10 as will be described in detail later.
When it is detected that a slot error has occurred in the data within the time slot allocated to the data slot, the data is replaced with pattern data composed of a predetermined data pattern and transmitted. By detecting that the frequency of the transmitted pattern data has reached the reference value (the same reference value as the reference value related to the slot error rate), the execution of the handover process or the channel switching process is started. That is, the communication adapter devices 18 and 19 can know the fact.

Accordingly, in the mobile radio data communication system according to the second embodiment, the dedicated signal line 1 connecting the radio base station 11 and the radio base station interface 13 is used.
Reference numeral 00 may be a structure having only a communication channel, and does not need to be modified as in the prior art mobile wireless data communication system while maintaining an existing signal line (that is, a digital wired line). In addition, the wireless base station interface 1
The digital wired line (including the public digital network 14) connecting between the terminal 3 and the data terminal 17 may have a structure having only a communication channel. No modification is required as in the data communication system.

FIG. 12 is a block diagram showing the configuration of the radio base station 11 and the communication adapter device 19.

In the figure, reference numeral 1200 denotes a line control unit;
Reference numeral 1202 denotes a buffer; 1203, a wireless signal transmission unit;
04 is a radio signal receiving unit, 1205 is a slot error detecting unit, 1206 is a slot error counting unit, 1207 is an error slot replacing unit, 1208 is a receiving level determining unit, and 1209.
Is a timer, 1210 is a control unit for controlling the entire radio base station 11, 1211 is a line control unit, 1212 is a pattern data detection unit, 1213 is a pattern data counting unit, 1214
Denotes a data terminal control unit, 1215 denotes a timer, and 1216 denotes a control unit for controlling the entire communication adapter device 19.

The configuration of the radio base station 12 is the same as the configuration of the radio base station 11, and the configuration of the communication adapter device 18 is the same as the configuration of the communication adapter device 19.

The configuration of mobile terminal 10 is also the same as that of radio base station 11, except that line control section 1200 and buffers 1201 and 1202 are not provided, and the subscriber provided in mobile terminal 10 is provided. The only difference is that there is an operation part (for example, a keypad or a display).

First, the operation of each block of the radio base station 11 will be described.

In the radio base station 11, the channel control unit 12
00 receives data transmitted from the digital wired line (that is, data transmitted by the data terminal 17),
The received data is stored in the buffer 1201. Radio signal transmitting section 1203 reads from buffer 1201 an amount of data that can be transmitted in one time slot, modulates the read data with an error detection code added thereto, and modulates the read data with a time slot assigned to mobile terminal 10. It transmits to the mobile terminal 10.

In radio base station 11, radio signal receiving section 1204 transmits data transmitted as a radio signal from mobile terminal 10 in the time slot allocated to mobile terminal 10 (ie, data transmitted from data terminal 16). Receive and demodulate. In the second embodiment, when data transmitted by the data terminal 16 is transmitted from the mobile terminal 10 to the radio base station 11, the data is
, An error detection code is added.

Subsequently, the slot error detecting section 1205
Using the error detection code, it is checked whether or not a slot error has occurred in the data demodulated by the wireless signal receiving unit 1204. If a slot error has occurred, the fact is notified to the slot error counting unit 1206. Notice. Note that the slot error detection unit 1205 checks the check result and the post-check data (data excluding the error detection code) regardless of the check result.
Is transferred to the error slot replacing section 1207.

Subsequently, the error slot replacing section 1207 calculates
The data received from the slot error detector 1205 is stored in the buffer 1202,
If the inspection result received from No. 5 indicates that a slot error has occurred, the data is replaced with pattern data composed of a predetermined data pattern and stored in the buffer 1202. The line control unit 1200 reads data stored in the buffer 1202, and sequentially transmits the read data to a digital wired line.

Thus, when a slot error occurs in the data transmitted by data terminal 16, radio base station 1
1 transmits the pattern data instead of the data to the communication adapter device 19. Similarly, when a slot error occurs in the data transmitted by the data terminal 17, the communication from the mobile terminal 10 is performed. Pattern data is transmitted to the adapter device 18 instead of the data.

On the other hand, the slot error counting section 1206 counts the number of occurrences of slot errors notified from the slot error detection section 1205 over a certain period in the past to calculate the slot error rate, and the calculated slot error rate is used as a reference. It is determined whether or not it has reached the value, and the determination result is notified to the control unit 1210. Further, reception level determination section 1208 determines whether or not the reception level of the data received by radio signal reception section 1204 has deteriorated from a reference value, and determines the determination result by control section 1.
Notify 210.

Control unit 1210 is notified by reception level determination unit 1208 that the reception level is degraded from the reference value, and is notified by slot error counting unit 1206 that the slot error rate has reached the reference value. If so, execution of the handover process is started.

Control unit 1210 does not notify reception level determination unit 1208 that the reception level is degraded from the reference value, and notifies slot error counter unit 1206 that the slot error rate has reached the reference value. If so, execution of the channel switching process is started.

Also, when the control unit 1210 starts execution of the handover process or the channel switching process, the error slot replacement unit stores the pattern data in the buffer 1202 irrespective of the inspection result received from the slot error detection unit 1205. 1207 is controlled. Therefore,
The channel control unit 1200 replaces the data received and demodulated by the radio signal receiving unit 1204 with the error slot replacing unit 1.
207 transmits the pattern data stored in the buffer 1202 to the digital wired line.

Thus, when the execution of the handover process or the channel switching process is started, the radio base station 1
1 is repeatedly transmitted from the mobile terminal 10 to the communication adapter device 18 when the handover process or the channel switching process is started. , And the pattern data is transmitted repeatedly.

[0198] When the handover process or the channel switching process is performed, the radio base station 11 sends the mobile terminal 1
Various control signals transmitted to 0 are generated by the control unit 1210, modulated by the wireless signal transmission unit 1203, and transmitted. When performing the handover process or the channel switching process, various control signals transmitted from the mobile terminal 10 to the radio base station 11 are transmitted to the radio signal receiving unit 12.
04, demodulated, and notified to the control unit 1210.

When the execution of the handover process or the channel switching process is started, the control unit 1210 sets a predetermined time (execution of the handover process and the channel switching process) in consideration of the case where the execution of the handover process and the channel switching process is stopped. It is necessary to set the time shorter than the time required for the operation.), The measurement by the timer 1209 is started.

Then, the control unit 1210
Before timeout of 9, the reception level determining unit 1208 notifies that the reception level has reached the reference value, and the slot error counting unit 1206 notifies that the slot error rate is lower than the reference value. Stops the execution of the handover process or the channel switching process,
The error slot replacement unit 1207 is controlled to stop storing the pattern data in the buffer 1202.

The control unit 1210 has a timer 1209
If timeout occurs, the error slot replacement unit 1207 is controlled to stop storing the pattern data in the buffer 1202 when the execution of the handover process or the channel switching process ends.

More specifically, the control unit 1210
If the process that started execution is a handover process when the time-out of 09 has timed out, a new communication path between the wireless base station (for example, the wireless base station 12) to be changed and the public digital network 14 is set. Then, when the communication path between the wireless base station 11 and the public digital network 14 is disconnected, the error slot replacement unit 1207 is controlled so as to stop storing the pattern data in the buffer 1202. The control unit 1210 of the mobile terminal 10 stores the pattern data in the buffer 1202 when the communication channel used for transmitting and receiving the radio signal between the mobile terminal 10 and the radio base station 11 is released. Is controlled to stop the error slot replacement.

More specifically, when timer 1209 times out, if the process started to be executed is a channel switching process, control unit 1210 allocates a new communication channel to mobile terminal 10 and sets a radio base station. When the communication channel used for transmitting and receiving the radio signal between the station 11 and the mobile terminal 10 is released, the error slot replacement unit 1207 is controlled so as to stop storing the pattern data in the buffer 1202. .

Thus, when the execution of the handover process or the channel switching process is stopped, and when the execution of the handover process or the channel switching process is completed, the transmission of the pattern data from the radio base station 11 to the communication adapter device 19. Is stopped, and similarly, when the execution of the handover process or the channel switching process is stopped, and when the execution of the handover process or the channel switching process ends, the mobile terminal 1
From 0, the transmission of the pattern data to the communication adapter device 18 is stopped.

FIG. 13 is a diagram showing an example of data received and demodulated by the radio signal receiving section 1204 of the radio base station 11 and data transmitted by the line control section 1200 of the radio base station 11.

In FIG. 13, reference numeral 1300 denotes data received and demodulated by radio signal receiving section 1204. Since this data 1300 is transmitted from mobile terminal 10 using the time slot allocated to mobile terminal 10, It becomes a burst signal.

Of the data 1300, 1301, 130
3, 1305, 1307 are data transmitted by the data terminal 16, and 1302, 1304, 1306, 130
Reference numeral 8 denotes an error detection code added when the mobile terminal 10 transmits transmission data as a wireless signal.

As described above, slot error detecting section 1205 generates error detecting codes 1302, 1304, 1306, and
Using 1308, data 1301, 1303, 130
It is checked whether or not a slot error has occurred at 5, 1307. If no slot error has occurred, an inspection result and data 1301, 1303, 13
05, 1307 to the error slot replacing section 1207.

As described above, error slot replacing section 1207 converts data 1301, 1303, 1305, 1307 received from slot error detecting section 1205 into
The data stored in the buffer 1202 is read out from the buffer 1202, and the line control unit 1200 reads out the data stored in the buffer 1202 and transmits the data to the digital wired line. The data transmitted by the data terminal 16 from the base station 11 to the communication adapter device 19 is transmitted as it is.

Now, the mobile terminal 10 is added to the data 1303 to which the error detection code 1304 is added by using a time slot.
Assuming that an error has occurred during transmission to the radio base station 11, the slot error detection unit 1205, as described above, transmits the test result indicating that a slot error has occurred and the data 1303 to the error slot. Replacement unit 1207
Hand over to

Further, as described above, error slot replacing section 1207 replaces data 1303 received from slot error detecting section 1205 with pattern data.
The line control unit 1200 stores the data (pattern data) stored in the buffer 1202.
Is read and transmitted to the digital wired line. If a slot error occurs in the data transmitted by the data terminal 16, the wireless base station 11 sends the communication adapter device 1
9, pattern data is transmitted instead of the data transmitted by the data terminal 16.

In FIG. 13, reference numeral 1310 denotes a radio base station 1
1 is transmitted by the line control unit 1200, and among the data 1310, 1311, 1313, and 1314 are:
Data 1301, 1305 transmitted by the data terminal 16
1307, and 1312 corresponds to the pattern data replaced by the error slot replacement unit 1207.

Next, the operation of each block of the communication adapter device 19 will be described.

In the communication adapter 19, the data terminal control unit 1214 receives the data transmitted from the data terminal 17, and the line control unit 1211 transmits the data to the digital wired line received by the data terminal control unit 1214.

In the communication adapter device 19, the line controller 1211 receives data transmitted from the digital wired line (ie, data transmitted by the data terminal 16), and the data terminal controller 1214 1211 transmits the received data to the data terminal 17.

Note that the line control unit 1211
According to the control of 16, a data communication link is set on the communication path between the communication adapter devices 18 and 19 with the line control unit 1211 of the communication adapter device 18 at the start of data communication.

On the other hand, the pattern data detector 1212
The line control unit 1211 checks whether the received data is pattern data, and if it is pattern data, notifies the pattern data counting unit 1213 of that fact. The pattern data counting unit 1213 calculates the pattern data detection rate by counting the number of times of detection of the pattern data notified from the pattern data detection unit 1212 over a certain period in the past, and calculates the calculated detection rate as the radio base station 11. The slot error counting unit 1206 determines whether the reference value is the same as the reference value used for the determination, and notifies the control unit 1216 of the determination result.

When the pattern data counting unit 1213 notifies that the detection rate has reached the reference value, the control unit 1216 determines that the execution of the handover process or the channel switching process has been started, and the data terminal 17 The data terminal control unit 1214 is controlled so as to stop the data transmission / reception operation.

As a result, when the execution of the handover process or the channel switching process is started, the communication adapter device 19 causes the data terminal 17 to stop the data transmission / reception operation.
Means that the data terminal 16 stops the data transmission / reception operation when the execution of the handover process or the channel switching process is started.

[0220] In the second embodiment, when the slot error rate reaches the reference value, the radio base station 11 and the mobile terminal 10 start executing the handover process or the channel switching process. Therefore, the communication adapter devices 18 and 19 determine whether or not the detection rate of the pattern data transmitted from the mobile terminal 10 and the wireless base station 11 has reached a reference value. It is determined whether or not the slot error rate at 10 has reached a reference value, and this determination is substituted for the determination as to whether or not the execution of the handover process or the channel switching process has been started.

If the control unit 1216 determines that the execution of the handover process or the channel switching process has been started, the control unit 1216 starts the measurement by the timer 1215 and notifies the control unit 1216 of the inspection result. Control. Note that the timer 1215
Is configured to timeout when measuring the same time as the time measured by the timer 1209 of the wireless base station 11 (a predetermined time in consideration of the case where the execution of the handover process and the channel switching process is stopped).

Then, the control unit 1216
If the pattern data detecting unit 1212 notifies that data other than the pattern data has been detected before the timeout of 5, it is determined that the execution of the handover process or the channel switching process has been stopped, and the data terminal 17 The data terminal control unit 1214 is controlled to restart the transmission / reception operation.

As a result, when the execution of the handover process or the channel switching process is stopped, the communication adapter device 19 causes the data terminal 17 to resume the data transmission / reception operation.
Means that when the execution of the handover process or the channel switching process is stopped, the data terminal 16 restarts the data transmission / reception operation.

The control unit 1216 has a timer 1215
If timeout occurs, it is determined that the execution of the handover process or the channel switching process has not been stopped,
The line controller 1211 is controlled so that a data communication link is re-established on a new communication path between the communication adapter devices 18 and 19. Then, the control unit 1216
If the setting of the data communication link succeeds, it is determined that the handover process or the channel switching process has been completed, and the data terminal control unit 1214 is controlled so that the data terminal 17 resumes the data transmission / reception operation.

Thus, when the execution of the handover process or the channel switching process is completed, the communication adapter device 19 causes the data terminal 17 to resume the data transmission / reception operation.
Means that the data terminal 16 restarts the data transmission / reception operation when the execution of the handover process or the channel switching process ends.

When the data transmitted from the data terminal 17 has the same value as the pattern data, the data terminal control unit 1214 transmits the pattern data of the communication adapter device 18 when the line control unit 1211 transmits the data as it is. Since it is detected by the data detection unit 1212,
Preferably, the data is converted to a close value different from the original value.

Further, by making the reference value used by pattern data counting section 1213 for the determination smaller than the reference value used by slot error counting section 1206 of radio base station 11 for the determination, the handover is performed. Before the execution of the process or the channel switching process is actually started, the data terminal 17 can stop the data transmission / reception operation, thereby enhancing the prevention of data loss.

Next, the flow of a handover process in the second embodiment will be described.

In the handover process according to the second embodiment, the sequence for transmitting and receiving various control signals between the mobile terminal 10 and the radio base stations 11 and 12 is shown in FIG.
Therefore, the following description focuses on differences from the flow of the handover process in the first embodiment.

For example, by transmitting and receiving a radio signal between the mobile terminal 10 and the radio base station (old radio base station) 11,
When performing data communication between the data terminal 16 connected to the mobile terminal 10 via the communication adapter device 18 and the data terminal 17 connected to the public digital network 14 via the communication adapter device 19, When the subscriber of the mobile terminal 10 moves, the reception level of the radio signal transmitted from the old radio base station 11 deteriorates at the mobile terminal 10 and the mobile terminal 10 receives the radio signal in the time slot allocated to the mobile terminal 10. The slot error rate, which is the frequency of occurrence of slot errors in data, increases.

Therefore, the mobile terminal 10 communicates with the old radio base station 1.
1 detects that the reception level of the radio signal transmitted from No. 1 has degraded from the reference value, and indicates a frequency at which a slot error occurs in data received as a radio signal in a time slot allocated to the mobile terminal 10. When it has detected that has reached the reference value, it transmits a channel switching request signal to the old radio base station 11 in order to change the radio base station that transmits and receives radio signals, and the old radio base station 11 When receiving the channel switching request signal transmitted from terminal 10, it transmits a channel switching instruction signal to mobile terminal 10.

As a result, the execution of the handover process is started. In the second embodiment, when the execution of the handover process is started, the mobile terminal 10 transmits the pattern data to the communication adapter 18. The old wireless base station 11 repeatedly transmits the pattern data to the communication adapter device 19 via the digital wired line.

In the second embodiment, when the mobile terminal 10 and the old radio base station 11 have a slot error in the data within the time slot allocated to the mobile terminal 10, the mobile terminal 10 and the old radio base station 11 After being replaced with the pattern data, the data is transmitted to the communication adapter devices 18 and 19.

According to the prior art, when the execution of the handover process is started, the data communication that has been performed so far is interrupted on the communication path between the mobile terminal 10 and the old radio base station 11, According to the second embodiment, according to the second embodiment, the detection rate of the pattern data transmitted from the mobile terminal 10 and the old wireless base station 11 is set as a reference. By detecting that the value has reached the value, it is determined that the execution of the handover process or the channel switching process has been started, and the data transmission / reception operations of the data terminals 16 and 17 are stopped. Will not occur.

Now, as shown in FIG. 10, the public digital network 14 disconnects the communication path connecting with the old radio base station 11 and changes the communication path with the new radio base station 12. The communication path is switched by newly setting, but the public digital network 14 transmits a disconnection signal to the old radio base station 11 to disconnect the communication path with the old radio base station 11. It has become.

Therefore, when the old radio base station 11 receives the disconnection signal transmitted from the public digital network 14, it releases the time slot allocated to the mobile terminal 10. In addition, the old radio base station 11 transmits a release signal to the mobile terminal 10 to release the time slot allocated to the mobile terminal 10.

In the second embodiment, when the time slot is released, the old radio base station 11 stops transmitting the pattern data to the communication adapter 19, and the mobile terminal 10 stops transmitting the pattern to the communication adapter 18. Data transmission will be stopped.

By the way, in the second embodiment, when the communication adapter devices 18 and 19 determine that the execution of the handover process or the channel switching process has been started, the measurement by the timer 1215 is started.
When the timer 1215 measures a predetermined time in consideration of the case where the execution of the handover process and the channel switching process is stopped, the timer 1215 is configured to time out. Therefore, the communication adapter devices 18 and 19 determine the timer that started the measurement. If a timeout has occurred in 1215, it is determined that the execution of the handover process or the channel switching process has not been stopped.

When the communication adapter devices 18 and 19 determine that the execution of the handover process or the channel switching process has not been stopped, the communication adapter devices 18 and 19 reset the data communication link on a new communication path with the other communication adapter device. Then, execution of the setting process is started. Note that, even if the setting process is started, the execution of the handover process is actually ended, and the data communication is restarted on a new communication path between the mobile terminal 10 and the new radio base station 12. Until this is possible, a data communication link cannot be set on the communication path between the communication adapter devices 18 and 19.

Then, the communication adapter devices 18 and 19
When the setting process succeeds in setting the data communication link,
It is determined that the execution of the handover process or the channel switching process has been completed, and the data transmission / reception operation of the data terminals 16 and 17 is restarted.

Therefore, according to the second embodiment, even when the handover process is executed during the data communication between the data terminals 16 and 17, the communication adapter devices 18 and 19 perform the handover process. When the execution is started, the data transmission / reception operation of the data terminals 16 and 17 is stopped, and when the execution of the handover process is completed, the data transmission / reception operation of the data terminals 16 and 17 is restarted. Communication can be continued smoothly.

Note that the old radio base station 11 is
In some cases, it may be necessary to transmit / receive a radio signal to / from itself again depending on the way in which the mobile station moves, and in consideration of such a case, a predetermined time after transmitting the channel switching instruction signal is set to the timer 1209. Measured by the timer 12
Until the timeout of 09, the transmission of the synchronization burst signal is continued so that the time slot used up to that time is secured. Note that the timer 12
The time measured by the timer 09 corresponds to the time measured by the timer 1215 of the communication adapter devices 18 and 19.

That is, when it becomes necessary for the mobile terminal 10 to transmit and receive radio signals to and from the old radio base station 11 again, and the execution of the handover process is stopped, the mobile terminal 1
0 and the old wireless base station 11 can restart the transmission and reception of the wireless signal after performing the synchronization process again using the same time slot as that used up to that time.

In the second embodiment, when the execution of the handover process is stopped, the mobile terminal 10 and the old radio base station 11 stop transmitting the pattern data to the communication adapter devices 18 and 19. Become.

Therefore, in the second embodiment, the pattern data is transmitted from the mobile terminal 10 and the old radio base station 11 to the communication adapter devices 18 and 19 before the timer 1215 of the communication adapter devices 18 and 19 times out. Since other data is transmitted, the communication adapter devices 18 and 19 determine that the execution of the handover process or the channel switching process has been stopped, and restart the data transmission / reception operation of the data terminals 16 and 17. Become. When it is determined that the execution of the handover process or the channel switching process has been stopped, the communication adapter devices 18 and 19 do not need to execute the above-described setting process.

Therefore, according to the second embodiment, even if the handover process started to be executed during the data communication between the data terminals 16 and 17 is stopped,
Since the communication adapter devices 18 and 19 resume the data transmission and reception operations of the data terminals 16 and 17 when the execution of the handover process is stopped, the data communication can be smoothly continued. .

In the above-described handover process, mobile terminal 10 detects that the reception level of the radio signal transmitted from old radio base station 11 has degraded from the reference value, and allocates it to mobile terminal 10. It detects that the slot error rate, which is the frequency of occurrence of a slot error in data received as a radio signal in a time slot, has reached a reference value, but the old radio base station 11
0, which indicates that the reception level of the radio signal transmitted from 0 has deteriorated below the reference value, and which is a frequency at which a slot error occurs in data received as a radio signal in a time slot allocated to the mobile terminal 10. Has reached the reference value, before receiving the channel switching request signal transmitted from the mobile terminal 10, the mobile terminal 10
, A channel switching instruction signal may be transmitted.

Next, the flow of a channel switching process in the second embodiment will be described.

In the channel switching processing in the second embodiment, the sequence for transmitting and receiving various control signals between the mobile terminal 10 and the radio base station 11 is the same as that in FIG. The following description focuses on the differences from the flow of the channel switching process in the embodiment.

For example, by transmitting / receiving a radio signal between the mobile terminal 10 and the radio base station 11, the data terminal 16 connected to the mobile terminal 10 via the communication adapter device 18 is transmitted.
And the public digital network 1 via the communication adapter device 19.
During data communication with the data terminal 17 connected to the communication terminal 4, if there is radio interference from the mobile terminal 10 in the vicinity, the mobile terminal 10
Although the reception level of the radio signal transmitted and received between the mobile terminal 10 and the mobile terminal 10 does not deteriorate, the slot error rate, which is the frequency at which a slot error occurs in data received as a radio signal in the time slot allocated to the mobile terminal 10, increases.

When the mobile terminal 10 detects that the slot error rate, which is the frequency of occurrence of a slot error in data received as a radio signal in the time slot allocated to the mobile terminal 10, has reached a reference value, the radio signal In order to change the time slot used for transmitting and receiving the communication channel, a communication channel switching request signal is transmitted to the radio base station 11, and the radio base station 11 transmits the communication channel switching request signal transmitted from the mobile terminal 10. Upon reception, the mobile station 10 transmits a communication channel switching instruction signal to the mobile terminal 10.

As a result, the execution of the channel switching process is started. In the second embodiment, when the execution of the channel switching process is started, the mobile terminal 10 sends a pattern to the communication adapter device 18. The data is repeatedly transmitted, and the wireless base station 11 repeatedly transmits the pattern data to the communication adapter device 19 via the digital wired line.

Note that, in the second embodiment, when a slot error has occurred in the data in the time slot allocated to the mobile terminal 10, the mobile terminal 10 and the radio base station 11 After the data is replaced with data, the data is transmitted to the communication adapter devices 18 and 19.

According to the prior art, when the execution of the channel switching process is started, the data communication that has been performed so far in the communication path between the mobile terminal 10 and the radio base station 11 is interrupted, According to the second embodiment, the communication adapter devices 18 and 19 are connected to the mobile terminal 10 and the radio base station 11 according to the second embodiment.
By detecting that the detection rate of the pattern data transmitted from the base station has reached the reference value, it is determined that the execution of the handover process or the channel switching process has been started, and the data transmission and reception operations of the data terminals 16 and 17 are stopped. Therefore, the above-mentioned problem does not occur.

Now, as shown in FIG. 11, the radio base station 11 releases the time slot (old time slot) used for transmitting and receiving radio signals to and from the mobile terminal 10, and sets a new time slot. By allocating the slot to the mobile terminal 10, the time slot used for transmitting and receiving the radio signal is changed. However, the radio base station 11 uses the old time used for transmitting and receiving the radio signal to and from the mobile terminal 10. A release signal is transmitted to the mobile terminal 10 to release the slot.

In the second embodiment, when the old time slot is released, the radio base station 11 stops transmitting the pattern data to the communication adapter 19, and the mobile terminal 10 Data transmission will be stopped.

By the way, in the second embodiment, when the communication adapter devices 18 and 19 determine that the execution of the handover process or the channel switching process is started, the measurement by the timer 1215 is started.
When the timer 1215 measures a predetermined time in consideration of the case where the execution of the handover process and the channel switching process is stopped, the timer 1215 is configured to time out. Therefore, the communication adapter devices 18 and 19 determine the timer that started the measurement. If a timeout has occurred in 1215, it is determined that the execution of the handover process or the channel switching process has not been stopped.

If the communication adapter devices 18 and 19 determine that the execution of the handover process or the channel switching process has not been stopped, the communication adapter devices 18 and 19 reset the data communication link on a new communication path with the other communication adapter device. Then, execution of the setting process is started. Note that, even if the setting process is started, the execution of the channel switching process is actually completed, and the data is set on a new communication path between the mobile terminal 10 and the radio base station 11 using a new time slot. Until the communication can be resumed, the communication adapter devices 18, 1
No data communication link can be set up on the communication path between the nine communication paths.

Therefore, the communication adapter devices 18 and 19
When the setting process succeeds in setting the data communication link,
It is determined that the execution of the handover process or the channel switching process has been completed, and the data transmission / reception operation of the data terminals 16 and 17 is restarted.

Therefore, according to the second embodiment, even when the channel switching process is executed during data communication between the data terminals 16 and 17, the communication adapter devices 18 and 19 perform the channel switching. When the execution of the processing is started, the data transmission / reception operations of the data terminals 16 and 17 are stopped, and when the execution of the channel switching processing is completed, the data transmission / reception operations of the data terminals 16 and 17 are restarted. Therefore, data communication can be smoothly continued.

In consideration of the case where radio interference to mobile terminal 10 is eliminated, radio base station 11 transmits a predetermined time after transmitting the communication channel switching instruction signal to timer 120.
9, until the timer 1209 times out, by continuing to transmit the synchronization burst signal,
The time slot used so far is reserved. The time measured by the timer 1209 corresponds to the time measured by the timer 1215 of the communication adapter devices 18 and 19.

That is, when the radio interference with the mobile terminal 10 is canceled and the execution of the channel switching process is stopped, the mobile terminal 10 and the radio base station 11 operate at the same time as the time slot used so far. After performing the synchronization process again using the slot, transmission and reception of the wireless signal can be resumed.

In the second embodiment, when the execution of the channel switching process is stopped, the mobile terminal 10 and the radio base station 11 stop transmitting the pattern data to the communication adapters 18 and 19. Become.

Therefore, in the second embodiment, before the timer 1215 of the communication adapter devices 18 and 19 times out, the mobile terminal 10 and the radio base station 11 transmit the data other than the pattern data to the communication adapter devices 18 and 19. Is transmitted, the communication adapter devices 18 and 19 determine that the execution of the handover process or the channel switching process has been stopped, and the data terminal 1
The data transmission / reception operations 6 and 17 are restarted.
When it is determined that the execution of the handover process or the channel switching process has been stopped, the communication adapter devices 18 and 19 do not need to execute the above-described setting process.

Therefore, according to the second embodiment, even if the channel switching process started to be executed during data communication between the data terminals 16 and 17 is stopped,
Since the communication adapter devices 18 and 19 resume the data transmission and reception operations of the data terminals 16 and 17 when the execution of the channel switching process is stopped, the data communication can be smoothly continued. Become.

In the above-described channel switching process, the mobile terminal 10 determines that the slot error rate, which is the frequency at which slot errors occur in data received as radio signals in the time slot allocated to the mobile terminal 10, reaches the reference value. However, the slot error rate, which is the frequency at which a slot error occurs in data received as a radio signal by the radio base station 11 in the time slot allocated to the mobile terminal 10, has reached the reference value. When detecting that, before receiving the traffic channel switching request signal transmitted from the mobile terminal 10, the mobile station 10 may transmit a traffic channel switching instruction signal to the mobile terminal 10 to instruct a new time slot. Good.

In the digital mobile telephone network adopting the TDMA system, the mobile terminal 10 detects that the slot error rate has reached the reference value before the radio base station 11, It is conceivable that the station 11 detects that the slot error rate has reached the reference value before the mobile terminal 10, and in any case, the execution of the handover process or the channel switching process starts at that time. Is done.

In the above-described first embodiment, when detecting that pattern data has been received, communication adapter devices 18 and 19 immediately determine that execution of handover processing or channel switching processing has been started. However, in the second embodiment, when it is detected that the pattern data detection rate has reached the reference value, it is determined that the execution of the handover process or the channel switching process has been started. I have.

Therefore, in the second embodiment, which one of the communication adapter devices 18 and 19 determines which of the mobile terminal 10 and the radio base station 11 first detects that the slot error rate has reached the reference value. On the other hand, a phenomenon may occur in which the execution of the handover process or the channel switching process is started before detecting that the detection rate of the pattern data has reached the reference value.

However, actually, when the mobile terminal 10 and the radio base station 11 start executing the handover process or the channel switching process, the mobile terminal 10 and the radio base station 11 repeatedly transmit pattern data instead of the data transmitted by the data terminals 16 and 17. Therefore, if the time elapses, the communication adapter devices 18 and 19 will detect that the pattern data detection rate has reached the reference value. Even if it does not reach, it may be determined that the execution of the handover process or the channel switching process has been started when the number of times the pattern data is continuously received reaches a predetermined number.

In order to do this, the pattern data counting unit 1213 counts the number of times of detection of pattern data continuously notified from the pattern data detection unit 1212, and the counted number of detections reaches a predetermined number. In this case, the control unit 1216 is notified of this fact. When the control unit 1216 is notified from the pattern data counting unit 1213 that the number of detections has reached a predetermined number,
The fact that the detection rate has reached the reference value indicates that the pattern data counting unit 12
Even if the notification is not received from 13, it may be determined that the execution of the handover process or the channel switching process has been started.

In the mobile radio data communication system according to the embodiment of the present invention described above, when connecting the data terminal 16 to the mobile terminal 10, the communication adapter device 18 is interposed and the data terminal 17 is connected to the digital terminal. When connecting to a digital mobile telephone network via a wired line,
Since the communication adapter device 19 is interposed, the data terminals 16 and 17 do not need to be modified, but the data terminals 16 and 17 are modified and the communication adapter devices 18 and 17 are modified.
The data terminals 16 and 17 may have 19 functions.

Hereinafter, an embodiment in which the functions of the communication adapter devices 18 and 19 are provided to the data terminals 16 and 17 without the intervention of the communication adapter devices 18 and 19 will be described.
An embodiment will be described.

The configuration of the mobile radio data communication system of the third embodiment is the same as that of FIG. 1, except that the communication adapter devices 18 and 19 are not present.

In the mobile radio data communication system according to the third embodiment, the mobile terminal 10
And the radio base stations 11 and 12 repeatedly transmit pattern data composed of a predetermined data pattern between the start and the end of the execution of any one of the handover process and the channel switching process. 1
By detecting the transmitted pattern data, the data terminals 16 and 17 can know that the execution of the handover process or the channel switching process has started.

Therefore, in the mobile radio data communication system according to the third embodiment, the dedicated signal line 1 connecting the radio base station 11 and the radio base station interface 13 is used.
Reference numeral 00 may be a structure having only a communication channel, and does not need to be modified as in the prior art mobile wireless data communication system while maintaining an existing signal line (that is, a digital wired line). In addition, the wireless base station interface 1
The digital wired line (including the public digital network 14) connecting between the terminal 3 and the data terminal 17 may have a structure having only a communication channel. No modification is required as in the data communication system.

The data terminal 17 may be connected to the digital fixed telephone 15.

FIG. 14 is a block diagram showing the structure of the data terminal 17.

In the figure, 1400 is a communication processing unit, 1401 is an information processing unit, 1402 is a line control unit, 1403 is a pattern data detecting unit, 1404 is a data transmitting unit, 1405 is a data receiving unit, 1406 is a timer, and 1407 is a communication unit. The control unit controls the entire processing unit 1400.

The configuration of the radio base station 11 is the same as the configuration of the radio base station shown in FIG.

The configuration of the radio base station 12 is the same as the configuration of the radio base station 11, and the configuration of the data terminal 16 is
The configuration is the same as that of the data terminal 17.

Also, the configuration of mobile terminal 10 is the same as that of radio base station 11, except that line control section 900 and buffers 901 and 902 are not provided, and the subscriber provided for mobile terminal 10 is provided. Operation part of (for example,
Keypad and display).

Since the operation of each block of the radio base station 11 is the same as that of the first embodiment, only the operation of each block of the data terminal 17 will be described below.

In the data terminal 17, the information processing section 14
01 processes data received from the communication processing unit 1400 (that is, data transmitted by the data terminal 16) and processes data input from a data input unit (not shown) or data stored in the information processing unit 1401. Then, it is delivered to the communication processing unit 1400.

The communication processing section 1400 includes the information processing section 140
1 to the data terminal 16 or
Data transmitted from the data terminal 16 is received and delivered to the information processing unit 1401. The communication processing unit 1400 performs data compression processing, framing processing, and the like on data transmitted to the data terminal 16 as necessary, and performs data decompression processing, framing processing, Error correction processing, retransmission processing, and the like can be performed.

In communication processing section 1400, when data transmission section 1404 receives data from information processing section 1401, the data transmission section 1404 subjects the received data to framing processing, data compression processing, and the like, and then passes it to line control section 1402. The line controller 1402 transmits the data received from the data transmitter 1404 to a digital wired line.

In communication processing section 1400, line control section 1402 stores data transmitted from a digital wired line (ie, data transmitted by data terminal 16).
And the data receiving unit 1405
2 transfers the received data to the information processing unit 1401.

It should be noted that the line control unit 1402
07, the data terminal 1 communicates with the line controller 1402 of the data terminal 16 at the start of data communication.
A data communication link is set on a communication path between the communication channels 6 and 17.

On the other hand, the pattern data detector 1403
The line control unit 1402 checks whether the received data is pattern data, and if the data is pattern data, notifies the control unit 1407 to that effect.

When notified of the detection of the pattern data from pattern data detecting section 1403, control section 1407 determines that the execution of the handover processing or the channel switching processing has been started, and makes the data transmission and reception operations stop. Transmission unit 1404 and data reception unit 1405
Control.

As a result, when the execution of the handover process or the channel switching process is started, the data terminal 17 stops the data transmission / reception operation. Similarly, the data terminal 16 performs the handover process or the channel switching process. Is started, the data transmission / reception operation is stopped.

If the control unit 1407 determines that the execution of the handover process or the channel switching process has been started, the control unit 1407 starts the measurement by the timer 1406 and notifies the control unit 1407 of the inspection result. Control. Note that the timer 1406
Is configured to timeout when measuring the same time as the time measured by the timer 907 of the wireless base station 11 (a predetermined time in consideration of the case where the execution of the handover process and the channel switching process is stopped).

Then, the control unit 1407
If the pattern data detection unit 1403 notifies that data other than the pattern data has been detected before the time-out of 6, it is determined that the execution of the handover process or the channel switching process has been stopped and the data transmission / reception operation is resumed. The data transmission unit 1404 and the data reception unit 1405 are controlled to perform the operation.

As a result, when the execution of the handover process or the channel switching process is stopped, the data terminal 17 restarts the data transmission / reception operation. Similarly, the data terminal 16 performs the handover process or the channel switching process. Is stopped, the data transmission / reception operation is restarted.

The control unit 1407 has a timer 1406
If timeout occurs, it is determined that the execution of the handover process or the channel switching process has not been stopped,
The line controller 1402 is controlled so that a data communication link is re-established on a new communication path between the data terminals 16 and 17. Then, when the line control unit 1402 successfully sets the data communication link, the control unit 1407 determines that the execution of the handover process or the channel switching process has been completed,
In order to restart the data transmission / reception operation, the data transmission unit 140
4 and the data receiving unit 1405 are controlled.

Thus, when the execution of the handover process or the channel switching process is completed, the data terminal 17 restarts the data transmission / reception operation. Similarly, the data terminal 16 performs the handover process or the channel switching process. When the execution is completed, the data transmission / reception operation is restarted.

Note that the control unit 1407 is
While the 404 and the data receiving unit 1405 stop the data transmission / reception operation, the line control unit 1402 is controlled so as to maintain the connection state to the public digital network 14.

When the data received from information processing section 1401 has the same value as the pattern data, data transmission section 1404 transmits the pattern data of data terminal 16 when line control section 1402 transmits the data as it is. Since the data is detected by the unit 1403, it is preferable to convert the data into a close value different from the original value.

Next, the flow of a handover process in the third embodiment will be described.

In the handover process in the third embodiment, the sequence for transmitting and receiving various control signals between the mobile terminal 10 and the radio base stations 11 and 12 is shown in FIG.
Therefore, the following description focuses on differences from the flow of the handover process in the first embodiment.

For example, by transmitting and receiving a radio signal between the mobile terminal 10 and the radio base station (old radio base station) 11,
When a subscriber of the mobile terminal 10 moves while performing data communication between the data terminal 16 connected to the mobile terminal 10 and the data terminal 17 connected to the public digital network 14, the mobile terminal 10 Is the old radio base station 11
The reception level and the reception quality of the radio signal transmitted from the communication device deteriorate.

[0302] Therefore, the mobile terminal 10 communicates with the old radio base station 1.
When it is detected that both the reception level and the reception quality of the radio signal transmitted from No. 1 have degraded from the reference values, the old radio base station 11 is switched to the channel to change the radio base station that transmits and receives the radio signal. When transmitting the request signal and receiving the channel switching request signal transmitted from the mobile terminal 10, the old radio base station 11 transmits a channel switching instruction signal to the mobile terminal 10.

[0303] As a result, the execution of the handover process is started. In the third embodiment, when the execution of the handover process is started, the mobile terminal 10 repeats the pattern data to the data terminal 16. Thus, the old wireless base station 11 repeatedly transmits the pattern data to the data terminal 17 via the digital wired line.

According to the prior art, when the execution of the handover process is started, the data communication which has been performed so far in the communication path between the mobile terminal 10 and the old radio base station 11 is interrupted. According to the third embodiment, the data terminals 16 and 17 detect the pattern data transmitted from the mobile terminal 10 and the old radio base station 11 according to the third embodiment. Since it is determined that the execution of the handover process or the channel switching process has been started and the data transmission / reception operation is stopped, the above-described problem does not occur.

Now, as shown in FIG. 10, the public digital network 14 disconnects the communication path connecting with the old radio base station 11 and changes the communication path with the new radio base station 12. The communication path is switched by newly setting, but the public digital network 14 transmits a disconnection signal to the old radio base station 11 to disconnect the communication path with the old radio base station 11. It has become.

[0306] Therefore, when receiving the disconnection signal transmitted from the public digital network 14, the old radio base station 11 releases the communication channel allocated to the mobile terminal 10. Further, the old radio base station 11 transmits a release signal to the mobile terminal 10 in order to release the communication channel allocated to the mobile terminal 10.

In the third embodiment, when the communication channel is released, the old radio base station 11
Transmission of pattern data to the mobile terminal 10
Means that the transmission of the pattern data to the data terminal 16 is stopped.

By the way, in the third embodiment, when the data terminals 16 and 17 determine that the execution of the handover process or the channel switching process has been started, the timer 1
The measurement by 406 is started. When the timer 1406 measures a predetermined time in consideration of the case where the execution of the handover process and the channel switching process is stopped, the timer 1406 is configured to time out.
If timeout occurs, it is determined that the execution of the handover process or the channel switching process has not been stopped.

If the data terminals 16 and 17 determine that the execution of the handover process or the channel switching process has not been stopped, the data terminals 16 and 17 reestablish a data communication link on a new communication path with the other data terminal. Start execution of the setting process. In addition, even if the setting process is started, actually, the execution of the handover process ends,
Until data communication can be resumed on a new communication path between the mobile terminal 10 and the new radio base station 12, a data communication link cannot be established on the communication path between the data terminals 16 and 17. .

[0310] Therefore, when the setting process succeeds in setting the data communication link, the data terminals 16 and 17 determine that the execution of the handover process or the channel switching process has been completed, and restart the data transmission / reception operation.

Therefore, according to the third embodiment, even when the handover process is executed during the data communication between the data terminals 16 and 17,
17, when the execution of the handover process is started,
Since the data transmission / reception operation is stopped and the data transmission / reception operation is restarted when the execution of the handover process is completed, the data communication can be smoothly continued.

Note that the old radio base station 11 is
In some cases, it may be necessary to transmit and receive a radio signal to / from itself again depending on the way in which the mobile station moves, and in consideration of such a case, a predetermined time after transmitting the channel switching instruction signal is set to the timer 907. Timer 907
Until the time-out occurs, the transmission of the synchronous burst signal is continued so that the communication channel used up to that time is secured. The time measured by the timer 907 is equal to the timer 140 of the data terminals 16 and 17.
6 corresponds to the time to be measured.

In other words, when the mobile terminal 10 needs to transmit and receive a radio signal to and from the old radio base station 11 again and the execution of the handover process is stopped, the mobile terminal 1
0 and the old radio base station 11 can restart the transmission and reception of the radio signal after performing the synchronization process again using the same communication channel as the communication channel used so far.

In the third embodiment, when the execution of the handover process is stopped, the mobile terminal 10 and the old radio base station 11 stop transmitting the pattern data to the data terminals 16 and 17. .

Therefore, in the third embodiment, before the timer 1406 of the data terminals 16 and 17 times out, the mobile terminal 10 and the old radio base station 11 transmit data data other than pattern data to the data terminals 16 and 17. Since data is to be transmitted, the data terminals 16, 1
7 determines that the execution of the handover process or the channel switching process has been stopped, and restarts the data transmission / reception operation. When the data terminals 16 and 17 determine that the execution of the handover process or the channel switching process has been stopped, it is not necessary to execute the above-described setting process.

Therefore, according to the third embodiment, even if the handover process started to be executed during the data communication between the data terminals 16 and 17 is stopped,
Since the data terminals 16 and 17 resume the data transmission / reception operation when the execution of the handover process is stopped, the data communication can be smoothly continued.

[0317] In the above-described handover process, the mobile terminal 10 detects that both the reception level and the reception quality of the radio signal transmitted from the old radio base station 11 have deteriorated from the reference value. When the old radio base station 11 detects that both the reception level and the reception quality of the radio signal transmitted from the mobile terminal 10 have degraded from the reference values, the old radio base station 11 receives the channel switching request signal transmitted from the mobile terminal 10. Before, for the mobile terminal 10,
A channel switching instruction signal may be transmitted.

Next, the flow of the channel switching process in the third embodiment will be described.

In the channel switching processing in the third embodiment, the sequence for transmitting and receiving various control signals between the mobile terminal 10 and the radio base station 11 is the same as in FIG. The following description focuses on the differences from the flow of the channel switching process in the embodiment.

For example, by transmitting and receiving a radio signal between the mobile terminal 10 and the radio base station 11, the data terminal 16 connected to the mobile terminal 10 and the data terminal 17 connected to the public digital network 14 If there is radio interference from a nearby mobile terminal 10 during data communication between the mobile terminals 10, the reception level of a radio signal transmitted and received between the mobile terminal 10 and the radio base station 11 is degraded. However, the reception quality is degraded.

[0321] Therefore, the mobile terminal 10 communicates with the radio base station 11
When it is detected that the reception quality of the radio signal transmitted from the base station has deteriorated below the reference value, a communication channel switching request signal is sent to the radio base station 11 in order to change the communication channel used for transmitting and receiving the radio signal. Upon transmitting, upon receiving the traffic channel switching request signal transmitted from the mobile terminal 10, the radio base station 11 transmits a traffic channel switching instruction signal to the mobile terminal 10.

As a result, the execution of the channel switching process is started. In the third embodiment, when the execution of the channel switching process is started, the mobile terminal 10 sends the pattern data to the data terminal 16. Is transmitted repeatedly, and the wireless base station 11 repeatedly transmits the pattern data to the data terminal 17 via the digital wired line.

According to the prior art, when the execution of the channel switching process is started, the data communication that has been performed up to that point in the communication path between the mobile terminal 10 and the radio base station 11 is interrupted. Although the above-described problem has been caused, according to the third embodiment, the data terminal 1
By detecting the pattern data transmitted from the mobile terminal 10 and the radio base station 11, the mobile terminals 6 and 17 determine that the execution of the handover process or the channel switching process has been started, and stop the data transmission / reception operation. Therefore, the above-mentioned problem does not occur.

[0324] As shown in FIG. 11, the radio base station 11 releases the communication channel (old communication channel) used for transmitting and receiving radio signals to and from the mobile terminal 10, and performs a new communication. By allocating the channel to the mobile terminal 10, the communication channel used for transmitting and receiving the radio signal is changed. However, the radio base station 11 uses the old communication used for transmitting and receiving the radio signal with the mobile terminal 10. In order to release the channel, a release signal is transmitted to the mobile terminal 10.

In the third embodiment, when the old communication channel is released, the radio base station 11
Transmission of pattern data to the mobile terminal 10
Means that the transmission of the pattern data to the data terminal 16 is stopped.

By the way, in the third embodiment, when the data terminals 16 and 17 determine that the execution of the handover process or the channel switching process has been started, the timer 1
The measurement by 406 is started. When the timer 1406 measures a predetermined time in consideration of the case where the execution of the handover process and the channel switching process is stopped, the timer 1406 is configured to time out.
If timeout occurs, it is determined that the execution of the handover process or the channel switching process has not been stopped.

If the data terminals 16 and 17 determine that the execution of the handover process or the channel switching process has not been stopped, the data terminals 16 and 17 reset the data communication link on a new communication path with the other data terminal. Start execution of the setting process. In addition, even if the setting process is started, actually, the execution of the channel switching process ends,
Until data communication can be resumed on a new communication path using a new communication channel between the mobile terminal 10 and the radio base station 11, a data communication link is set on the communication path between the data terminals 16 and 17. I can't.

Therefore, when the setting process succeeds in setting the data communication link, the data terminals 16 and 17 determine that the execution of the handover process or the channel switching process is completed, and restart the data transmission / reception operation.

Therefore, according to the third embodiment, even if the channel switching process is executed during the data communication between the data terminals 16 and 17,
17, when the execution of the channel switching process is started,
Since the data transmission / reception operation is stopped and the data transmission / reception operation is resumed when the execution of the channel switching process is completed, the data communication can be smoothly continued.

[0330] In consideration of the case where radio interference to mobile terminal 10 is eliminated, radio base station 11 sets timer 907 to a predetermined time after transmitting the communication channel switching instruction signal.
Until the timer 907 times out, the transmission of the synchronous burst signal is continued to secure the old communication channel. Note that the time measured by the timer 907 corresponds to the time measured by the timer 1406 of the data terminals 16 and 17.

[0331] That is, when the radio interference with the mobile terminal 10 is eliminated and the execution of the channel switching process is stopped, the mobile terminal 10 and the radio base station 11 communicate with the same communication channel as the one used before. After performing the synchronization process again using the channel, transmission and reception of the wireless signal can be resumed.

In the third embodiment, when the execution of the channel switching process is stopped, the mobile terminal 10 and the radio base station 11 stop transmitting the pattern data to the data terminals 16 and 17. .

Therefore, in the third embodiment, before the timer 1406 of the data terminals 16 and 17 times out, the mobile terminal 10 and the radio base station 11 transmit data other than pattern data to the data terminals 16 and 17. Is transmitted, the data terminals 16, 17
Determines that the execution of the handover process or the channel switching process has been stopped, and restarts the data transmission / reception operation. When the data terminals 16 and 17 determine that the execution of the handover process or the channel switching process has been stopped, it is not necessary to execute the above-described setting process.

Therefore, according to the third embodiment, even if the channel switching process started during data communication between the data terminals 16 and 17 is stopped,
Since the data terminals 16 and 17 resume the data transmission / reception operation when the execution of the channel switching process is stopped, the data communication can be smoothly continued.

[0335] In the above-described channel switching process, the mobile terminal 10 detects that the reception quality of the radio signal transmitted from the radio base station 11 has deteriorated from the reference value. 11 detects that the reception quality of the radio signal transmitted from the mobile terminal 10 has degraded from a reference value, before the mobile terminal 10 receives the call channel switching request signal transmitted from the mobile terminal 10.
, A communication channel switching instruction signal may be transmitted to instruct a new communication channel.

In the third embodiment, the data terminals 16 and 17 specify which processing has been started only by knowing that the execution of the handover processing or the channel switching processing has been started. Can't,
If the pattern data transmitted during execution of the handover process and the pattern data transmitted during execution of the channel switching process have different values, the data terminals 16 and 17 determine whether the execution of the handover process has started or the execution of the channel switching process. It can be specified whether or not is started.

Incidentally, the third embodiment described above can also be realized when the digital mobile telephone network adopts the TDMA system.

When the digital mobile telephone network employs the TDMA system, the fourth embodiment described below can be realized.

The configuration of the mobile radio data communication system of the fourth embodiment is the same as that of FIG. 1, but differs from the third embodiment in that the communication adapter devices 18 and 19 are not present. .

However, in a digital mobile telephone network adopting the TDMA system, it is general to use a slot error rate, which is a frequency at which a slot error occurs in data in a time slot, as an index of radio signal reception quality. When the slot error rate reaches the reference value, the mobile terminal 10 and the radio base stations 11 and 12 determine that the reception quality of the radio signal has deteriorated from the reference value. That is, in the digital mobile telephone network adopting the TDMA system, the mobile terminal 10 and the radio base stations 11 and 12 each monitor the reception level of the radio signal and calculate the slot error rate. Yes,
If the reception level has deteriorated below the reference value and the slot error rate has reached the reference value, a handover process is executed, and if the slot error rate has reached the reference value, a channel switching process is executed. It has become.

Therefore, in the mobile radio data communication system of the fourth embodiment, the mobile terminal 10 and the radio base stations 11, 12 are connected to the mobile terminal 10 as will be described in detail later.
When it is detected that a slot error has occurred in the data in the time slot allocated to the data terminal, the data is replaced with pattern data composed of a predetermined data pattern and transmitted. By detecting that the frequency of the transmitted pattern data has reached the reference value (the same reference value as the reference value related to the slot error rate), the execution of the handover process or the channel switching process has been started. To the data terminals 16 and 17.

Therefore, in the mobile radio data communication system according to the fourth embodiment, the dedicated signal line 1 connecting the radio base station 11 and the radio base station interface 13 is used.
Reference numeral 00 may be a structure having only a communication channel, and does not need to be modified as in the prior art mobile wireless data communication system while maintaining an existing signal line (that is, a digital wired line). In addition, the wireless base station interface 1
The digital wired line (including the public digital network 14) connecting between the terminal 3 and the data terminal 17 may have a structure having only a communication channel. No modification is required as in the data communication system.

FIG. 15 is a block diagram showing the structure of the data terminal 17.

In the figure, 1500 is a communication processing unit, 1501 is an information processing unit, 1502 is a line control unit, 1503 is a pattern data detection unit, 1504 is a pattern data counting unit,
505 is a data transmission unit, 1506 is a data reception unit, 15
Reference numeral 07 denotes a timer, and reference numeral 1508 denotes a control unit that controls the entire communication processing unit 1500.

The configuration of the radio base station 11 is the same as the configuration of the radio base station shown in FIG.

Also, the configuration of the radio base station 12 is the same as the configuration of the radio base station 11, and the configuration of the data terminal 16 is
The configuration is the same as that of the data terminal 17.

[0347] The configuration of mobile terminal 10 is also the same as that of radio base station 11, except that line control section 1200 and buffers 1201 and 1202 are not provided, and the subscriber provided in mobile terminal 10 is provided. The only difference is that there is an operation part (for example, a keypad or a display).

Since the operation of each block of the radio base station 11 is the same as that of the second embodiment, only the operation of each block of the data terminal 17 will be described below.

In the data terminal 17, the information processing section 15
01 processes data received from the communication processing unit 1500 (that is, data transmitted by the data terminal 16), and processes data input from a data input unit (not shown) or data stored in the information processing unit 1501. Then, it is delivered to the communication processing unit 1500.

The communication processing section 1500 includes the information processing section 150
1 to the data terminal 16 or
The data transmitted from the data terminal 16 is received and delivered to the information processing unit 1501. The communication processing unit 1500 performs data compression processing, framing processing, and the like on data transmitted to the data terminal 16 as needed, and performs data decompression processing, framing processing, and the like on data transmitted from the data terminal 16. Error correction processing, retransmission processing, and the like can be performed.

In communication processing section 1500, when data transmission section 1505 receives data from information processing section 1501, the data transmission section 1505 subjects the received data to framing processing, data compression processing, and the like, and then passes it to line control section 1502. The line controller 1502 transmits the data received from the data transmitter 1505 to a digital wired line.

In communication processing section 1500, line control section 1502 stores data transmitted from a digital wired line (ie, data transmitted by data terminal 16).
Is received, and the data receiving unit 1506
2 transfers the received data to the information processing unit 1501.

Note that the line control unit 1502
08, the data terminal 1 communicates with the line controller 1502 of the data terminal 16 at the start of data communication.
A data communication link is set on a communication path between the communication channels 6 and 17.

On the other hand, the pattern data detecting section 1503
The line control unit 1502 checks whether the received data is pattern data, and if the data is pattern data, notifies the pattern data counting unit 1504 of that fact. The pattern data counting unit 1504 calculates the pattern data detection rate by counting the number of times of detection of the pattern data notified from the pattern data detection unit 1503 over a certain period in the past, and calculates the calculated detection rate as the radio base station 11. It is determined whether or not the slot error counting unit 1206 reaches the same reference value as the reference value used for the determination, and notifies the control unit 1508 of the determination result.

When the pattern data counting section 1504 notifies that the detection rate has reached the reference value, the control section 1508 determines that the execution of the handover processing or the channel switching processing has been started, and executes the data transmission / reception operation. The data transmission unit 1505 and the data reception unit 150
6 is controlled.

As a result, when the execution of the handover process or the channel switching process is started, the data terminal 17 stops the data transmission / reception operation. Similarly, the data terminal 16 performs the handover process or the channel switching process. Is started, the data transmission / reception operation is stopped.

In the fourth embodiment, when the slot error rate reaches the reference value, the radio base station 11 and the mobile terminal 10 start executing the handover process or the channel switching process. Therefore, the data terminals 16 and 17 correspond to the mobile terminal 10 and the radio base station 11.
By determining whether the detection rate of the pattern data transmitted from has reached the reference value, it is determined whether the slot error rate in the radio base station 11 and the mobile terminal 10 has reached the reference value, This determination is used in place of the determination as to whether execution of the handover process or the channel switching process has been started.

Also, in the fourth embodiment, before stopping the data receiving operation under the control of control unit 1508, data receiving unit 1506 can operate even if the data received by line control unit 1502 is pattern data. The pattern data is delivered to the information processing unit 1501. The inspection result is notified from the pattern data detection unit 1503, and the inspection result notified from the pattern data detection unit 1503 is the pattern data. If so, the pattern data may be discarded.

When the control unit 1508 determines that the execution of the handover process or the channel switching process has been started, the control unit 1508 starts the measurement by the timer 1507 and notifies the control unit 1508 of the inspection result. Control. Note that the timer 1507
Is configured to timeout when measuring the same time as the time measured by the timer 1209 of the wireless base station 11 (a predetermined time in consideration of the case where the execution of the handover process and the channel switching process is stopped).

Then, the control unit 1508 controls the timer 150
If the pattern data detection unit 1503 notifies that data other than the pattern data has been detected before the timeout of 7, it is determined that the execution of the handover process or the channel switching process has been stopped and the data transmission / reception operation is resumed. The data transmission unit 1505 and the data reception unit 1506 are controlled so as to perform the operations.

As a result, when the execution of the handover process or the channel switching process is stopped, the data terminal 17 restarts the data transmission / reception operation. Similarly, the data terminal 16 performs the handover process or the channel switching process. Is stopped, the data transmission / reception operation is restarted.

The control unit 1508 has a timer 1507
If timeout occurs, it is determined that the execution of the handover process or the channel switching process has not been stopped,
The line control unit 1502 is controlled so that a data communication link is re-established on a new communication path between the data terminals 16 and 17. Then, when the line control unit 1502 succeeds in setting the data communication link, the control unit 1508 determines that the execution of the handover process or the channel switching process has been completed,
In order to restart the data transmission / reception operation, the data transmission unit 150
5 and the data receiving unit 1506.

As a result, when the execution of the handover process or the channel switching process is completed, the data terminal 17 resumes the data transmission / reception operation. Similarly, the data terminal 16 performs the handover process or the channel switching process. When the execution is completed, the data transmission / reception operation is restarted.

Note that the control unit 1508 controls the data transmission unit 1
While the data transmission / reception unit 505 and the data reception unit 1506 stop, the line control unit 1502 is controlled so as to maintain the connection state to the public digital network 14.

If the data received from information processing section 1501 has the same value as the pattern data, data transmission section 1505 transmits the pattern data of data terminal 16 when line control section 1502 transmits the data as it is. Since the data is detected by the unit 1503, it is preferable to convert the data into a close value different from the original value.

Also, by making the reference value used by pattern data counting section 1504 for determination smaller than the reference value used by slot error counting section 1206 of radio base station 11 for determination, handover is performed. Before the execution of the process or the channel switching process is actually started, the data terminal 17 can stop the data transmission / reception operation, thereby enhancing the prevention of data loss.

Next, the flow of a handover process in the fourth embodiment will be described.

In the handover process according to the fourth embodiment, the sequence for transmitting and receiving various control signals between the mobile terminal 10 and the radio base stations 11 and 12 is shown in FIG.
Therefore, the following description focuses on differences from the flow of the handover process in the first embodiment.

For example, by transmitting and receiving a radio signal between the mobile terminal 10 and the radio base station (old radio base station) 11,
When a subscriber of the mobile terminal 10 moves while performing data communication between the data terminal 16 connected to the mobile terminal 10 and the data terminal 17 connected to the public digital network 14, the mobile terminal 10 Is the old radio base station 11
And the reception level of the radio signal transmitted from the mobile terminal 10 is degraded, and the slot error rate, which is the frequency of occurrence of a slot error in data received as a radio signal in the time slot allocated to the mobile terminal 10, increases.

[0370] Therefore, the mobile terminal 10 communicates with the old radio base station 1.
1 detects that the reception level of the radio signal transmitted from No. 1 has degraded from the reference value, and indicates a frequency at which a slot error occurs in data received as a radio signal in a time slot allocated to the mobile terminal 10. When it has detected that has reached the reference value, it transmits a channel switching request signal to the old radio base station 11 in order to change the radio base station that transmits and receives radio signals, and the old radio base station 11 When receiving the channel switching request signal transmitted from terminal 10, it transmits a channel switching instruction signal to mobile terminal 10.

As a result, the execution of the handover process is started. In the fourth embodiment, when the execution of the handover process is started, the mobile terminal 10 repeats the pattern data to the data terminal 16. Thus, the old wireless base station 11 repeatedly transmits the pattern data to the data terminal 17 via the digital wired line.

In the fourth embodiment, when a mobile station 10 and the old radio base station 11 have a slot error in the data in the time slot assigned to the mobile station 10, the mobile station 10 and the old radio base station 11 After replacing the data with the pattern data, the data is transmitted to the data terminals 16 and 17.

According to the prior art, when the execution of the handover process is started, the data communication that has been performed up to that point in the communication path between the mobile terminal 10 and the old radio base station 11 is interrupted. According to the fourth embodiment, the data terminals 16 and 17 are configured to reduce the detection rate of the pattern data transmitted from the mobile terminal 10 and the old radio base station 11 to the reference value. Is detected, the execution of the handover process or the channel switching process is determined to be started, and the data transmission / reception operation is stopped. Therefore, the above-described problem does not occur.

Now, as shown in FIG. 10, the public digital network 14 disconnects the communication path connecting with the old radio base station 11 and changes the communication path with the new radio base station 12. The communication path is switched by newly setting, but the public digital network 14 transmits a disconnection signal to the old radio base station 11 to disconnect the communication path with the old radio base station 11. It has become.

[0375] Therefore, upon receiving the disconnection signal transmitted from the public digital network 14, the old radio base station 11 releases the time slot allocated to the mobile terminal 10. In addition, the old radio base station 11 transmits a release signal to the mobile terminal 10 to release the time slot allocated to the mobile terminal 10.

In the fourth embodiment, when the time slot is released, the old radio base station 11
Transmission of pattern data to the mobile terminal 10
Means that the transmission of the pattern data to the data terminal 16 is stopped.

In the fourth embodiment, when the data terminals 16 and 17 determine that the execution of the handover process or the channel switching process has been started, the timer 1
507 is started. When the timer 1507 measures a predetermined time in consideration of the case where the execution of the handover process and the channel switching process is suspended, the timer 1507 times out.
If timeout occurs, it is determined that the execution of the handover process or the channel switching process has not been stopped.

When the data terminals 16 and 17 determine that the execution of the handover process or the channel switching process has not been stopped, the data terminals 16 and 17 reset the data communication link on a new communication path with the other data terminal. Start execution of the setting process. In addition, even if the setting process is started, actually, the execution of the handover process ends,
Until data communication can be resumed on a new communication path between the mobile terminal 10 and the new radio base station 12, a data communication link cannot be established on the communication path between the data terminals 16 and 17. .

[0379] Therefore, when the setting process succeeds in setting the data communication link, the data terminals 16 and 17 determine that the execution of the handover process or the channel switching process has been completed, and restart the data transmission / reception operation.

Therefore, according to the fourth embodiment, even if the handover process is executed during the data communication between the data terminals 16 and 17,
17, when the execution of the handover process is started,
Since the data transmission / reception operation is stopped and the data transmission / reception operation is restarted when the execution of the handover process is completed, the data communication can be smoothly continued.

Note that the old radio base station 11 is
In some cases, it may be necessary to transmit / receive a radio signal to / from itself again depending on the way in which the mobile station moves, and in consideration of such a case, a predetermined time after transmitting the channel switching instruction signal is set to the timer 1209. Measured by the timer 12
Until the timeout of 09, the transmission of the synchronization burst signal is continued so that the time slot used up to that time is secured. Note that the timer 12
The time measured by the timer 09 corresponds to the time measured by the timer 1507 of the data terminals 16 and 17.

In other words, when the mobile terminal 10 needs to transmit and receive a radio signal to and from the old radio base station 11 again and the execution of the handover process is stopped, the mobile terminal 1
0 and the old wireless base station 11 can restart the transmission and reception of the wireless signal after performing the synchronization process again using the same time slot as that used up to that time.

In the fourth embodiment, when the execution of the handover process is stopped, the mobile terminal 10 and the old radio base station 11 stop transmitting the pattern data to the data terminals 16 and 17. .

Therefore, in the fourth embodiment, before the timer 1507 of the data terminals 16 and 17 times out, the mobile terminal 10 and the old radio base station 11 transmit data data other than pattern data to the data terminals 16 and 17. Since data is to be transmitted, the data terminals 16, 1
7 determines that the execution of the handover process or the channel switching process has been stopped, and restarts the data transmission / reception operation. When the data terminals 16 and 17 determine that the execution of the handover process or the channel switching process has been stopped, it is not necessary to execute the above-described setting process.

Therefore, according to the fourth embodiment, even if the handover process started to be executed during the data communication between the data terminals 16 and 17 is stopped,
Since the data terminals 16 and 17 resume the data transmission / reception operation when the execution of the handover process is stopped, the data communication can be smoothly continued.

[0386] In the above-described handover process, the mobile terminal 10 detects that the reception level of the radio signal transmitted from the old radio base station 11 has degraded from the reference value, and allocates the radio signal to the mobile terminal 10. It detects that the slot error rate, which is the frequency of occurrence of a slot error in data received as a radio signal in a time slot, has reached a reference value, but the old radio base station 11
0, which indicates that the reception level of the radio signal transmitted from 0 has deteriorated below the reference value, and which is a frequency at which a slot error occurs in data received as a radio signal in a time slot allocated to the mobile terminal 10. Has reached the reference value, before receiving the channel switching request signal transmitted from the mobile terminal 10, the mobile terminal 10
, A channel switching instruction signal may be transmitted.

Next, the flow of a channel switching process in the fourth embodiment will be described.

In the channel switching processing in the fourth embodiment, the sequence for transmitting and receiving various control signals between the mobile terminal 10 and the radio base station 11 is the same as that shown in FIG. The following description focuses on the differences from the flow of the channel switching process in the embodiment.

For example, by transmitting and receiving a radio signal between the mobile terminal 10 and the radio base station 11, the data terminal 16 connected to the mobile terminal 10 and the data terminal 17 connected to the public digital network 14 If there is radio interference from a nearby mobile terminal 10 during data communication between the mobile terminals 10, the reception level of a radio signal transmitted and received between the mobile terminal 10 and the radio base station 11 is degraded. However, the slot error rate, which is the frequency of occurrence of a slot error in data received as a radio signal in the time slot allocated to the mobile terminal 10, increases.

[0390] If the mobile terminal 10 detects that the slot error rate, which is the frequency of occurrence of a slot error in data received as a radio signal in the time slot allocated to the mobile terminal 10, has reached the reference value, the radio signal In order to change the time slot used for transmitting and receiving the communication channel, a communication channel switching request signal is transmitted to the radio base station 11, and the radio base station 11 transmits the communication channel switching request signal transmitted from the mobile terminal 10. Upon reception, the mobile station 10 transmits a communication channel switching instruction signal to the mobile terminal 10.

As a result, the execution of the channel switching process is started. In the fourth embodiment, when the execution of the channel switching process is started, the mobile terminal 10 sends the pattern data to the data terminal 16. Is transmitted repeatedly, and the wireless base station 11 repeatedly transmits the pattern data to the data terminal 17 via the digital wired line.

In the fourth embodiment, when a mobile station 10 and a radio base station 11 have a slot error in the data in the time slot allocated to the mobile station 10, the mobile station 10 and the radio base station 11 After replacing the data, the data is transmitted to the data terminals 16 and 17.

According to the prior art, when the execution of the channel switching process is started, the data communication that has been performed so far in the communication path between the mobile terminal 10 and the radio base station 11 is interrupted. Although the above-described problem has been caused, according to the fourth embodiment, the data terminal 1
6 and 17 determine that the execution of the handover process or the channel switching process has been started by detecting that the detection rate of the pattern data transmitted from the mobile terminal 10 and the radio base station 11 has reached the reference value, Since the data transmission / reception operation is stopped, the above-described problem does not occur.

Now, as shown in FIG. 11, the radio base station 11 releases a time slot (old time slot) used for transmitting / receiving a radio signal to / from the mobile terminal 10 and adds a new time slot. By allocating the slot to the mobile terminal 10, the time slot used for transmitting and receiving the radio signal is changed. However, the radio base station 11 uses the old time used for transmitting and receiving the radio signal to and from the mobile terminal 10. A release signal is transmitted to the mobile terminal 10 to release the slot.

In the fourth embodiment, when the old time slot is released, the radio base station 11
Transmission of pattern data to the mobile terminal 10
Means that the transmission of the pattern data to the data terminal 16 is stopped.

In the fourth embodiment, when the data terminals 16 and 17 determine that the execution of the handover process or the channel switching process has started, the data terminals 16 and 17
507 is started. When the timer 1507 measures a predetermined time in consideration of the case where the execution of the handover process and the channel switching process is suspended, the timer 1507 times out.
If timeout occurs, it is determined that the execution of the handover process or the channel switching process has not been stopped.

If the data terminals 16 and 17 determine that the execution of the handover process or the channel switching process has not been stopped, the data terminals 16 and 17 reestablish a data communication link on a new communication path with the other data terminal. Start execution of the setting process. In addition, even if the setting process is started, actually, the execution of the channel switching process ends,
Until data communication can be resumed on a new communication path using a new time slot between the mobile terminal 10 and the radio base station 11, a data communication link is set up on the communication path between the data terminals 16 and 17. I can't.

Therefore, when the setting process succeeds in setting the data communication link, the data terminals 16 and 17 determine that the execution of the handover process or the channel switching process is completed, and restart the data transmission / reception operation.

Therefore, according to the fourth embodiment, even if the channel switching process is performed during data communication between the data terminals 16 and 17,
17, when the execution of the channel switching process is started,
Since the data transmission / reception operation is stopped and the data transmission / reception operation is resumed when the execution of the channel switching process is completed, the data communication can be smoothly continued.

[0400] In consideration of the case where radio interference to mobile terminal 10 is eliminated, radio base station 11 sets a predetermined time after transmitting the communication channel switching instruction signal to timer 120.
9, until the timer 1209 times out, by continuing to transmit the synchronization burst signal,
The time slot used so far is reserved. Note that the time measured by the timer 1209 corresponds to the time measured by the timer 1507 of the data terminals 16 and 17.

[0401] That is, when the radio interference with the mobile terminal 10 is eliminated and the execution of the channel switching process is stopped, the mobile terminal 10 and the radio base station 11 operate at the same time as the time slot used so far. After performing the synchronization process again using the slot, transmission and reception of the wireless signal can be resumed.

In the fourth embodiment, when the execution of the channel switching process is stopped, the mobile terminal 10 and the radio base station 11 stop transmitting the pattern data to the data terminals 16 and 17. .

Therefore, in the fourth embodiment, before the timer 1507 of the data terminals 16 and 17 times out, the mobile terminal 10 and the radio base station 11 transmit data other than pattern data to the data terminals 16 and 17. Is transmitted, the data terminals 16, 17
Determines that the execution of the handover process or the channel switching process has been stopped, and restarts the data transmission / reception operation. When the data terminals 16 and 17 determine that the execution of the handover process or the channel switching process has been stopped, it is not necessary to execute the above-described setting process.

[0404] Therefore, according to the fourth embodiment, even when the channel switching process started to be executed during the data communication between the data terminals 16 and 17 is stopped,
Since the data terminals 16 and 17 resume the data transmission / reception operation when the execution of the channel switching process is stopped, the data communication can be smoothly continued.

In the above-described channel switching process, the mobile terminal 10 determines that the slot error rate, which is the frequency of occurrence of a slot error in data received as a radio signal in the time slot allocated to the mobile terminal 10, reaches the reference value. However, the slot error rate, which is the frequency at which a slot error occurs in data received as a radio signal by the radio base station 11 in the time slot allocated to the mobile terminal 10, has reached the reference value. When detecting that, before receiving the traffic channel switching request signal transmitted from the mobile terminal 10, the mobile station 10 may transmit a traffic channel switching instruction signal to the mobile terminal 10 to instruct a new time slot. Good.

In the digital mobile telephone network adopting the TDMA system, the mobile terminal 10 detects before the radio base station 11 that the slot error rate has reached the reference value, It is conceivable that the station 11 detects that the slot error rate has reached the reference value before the mobile terminal 10, and in any case, the execution of the handover process or the channel switching process starts at that time. Is done.

In the third embodiment described above, when detecting that pattern data has been received, the data terminals 16 and 17 immediately determine that the execution of the handover process or the channel switching process has been started. However, in the fourth embodiment, when it is detected that the pattern data detection rate has reached the reference value, it is determined that the execution of the handover process or the channel switching process has been started. .

Therefore, in the fourth embodiment, one of the data terminals 16 and 17 depends on which of the mobile terminal 10 and the radio base station 11 detects that the slot error rate has reached the reference value first. On the other hand, before detecting that the detection rate of the pattern data has reached the reference value,
There may be a case where the execution of the handover process or the channel switching process is started.

However, actually, when the mobile terminal 10 and the radio base station 11 start execution of the handover process or the channel switching process, the mobile terminal 10 and the radio base station 11 repeatedly transmit pattern data instead of the data transmitted by the data terminals 16 and 17. Therefore, if the time elapses, the data terminals 16 and 17 will detect that the pattern data detection rate has reached the reference value, but the pattern data detection rate has reached the reference value. Even if the number of times the pattern data is continuously received reaches a predetermined number, it may be determined that the execution of the handover process or the channel switching process has been started.

[0410] To do so, the pattern data counting section 1504 counts the number of times of detection of pattern data continuously notified from the pattern data detection section 1503, and the counted number of detections reaches a predetermined number. In this case, the control unit 1508 is notified of this fact, and when the control unit 1508 is notified from the pattern data counting unit 1504 that the number of detections has reached a predetermined number,
The fact that the detection rate has reached the reference value is indicated by the pattern data counting unit 15.
Even if it is not notified from the terminal 04, it may be determined that the execution of the handover process or the channel switching process has been started.

[0411]

As described above, according to the present invention,
Using a digital mobile telephone network having a plurality of mobile terminals and a plurality of radio base stations, a data terminal connected to the mobile terminal and a data terminal connected to the digital mobile telephone network via a digital wired line are used. In a mobile wireless data communication system that performs data communication between them, these data terminals can perform handover processing and channel switching processing without modifying all of the existing digital wired lines or significantly modifying the software of mobile terminals. When the execution is started, there is an effect that the data transmission / reception operation can be stopped.

Further, according to the present invention, a data terminal connected to a mobile terminal and a data terminal connected to a digital mobile telephone network via a digital wired line execute a handover process and a channel switching process. Is completed, the data transmission / reception operation can be resumed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a mobile wireless data communication system according to a first embodiment.

FIG. 2 is a configuration diagram of a conventional digital mobile telephone network.

FIG. 3 is a sequence diagram of a handover process in a conventional digital mobile telephone network.

FIG. 4 is a sequence diagram of a channel switching process in a conventional digital mobile telephone network.

FIG. 5 is an explanatory diagram showing a configuration example of a frame formed at the time of data communication.

FIG. 6 is an explanatory diagram showing a configuration example of a frame formed at the time of data communication.

FIG. 7 is an explanatory diagram showing a configuration example of a frame formed at the time of data communication.

FIG. 8 is a configuration diagram of a mobile radio data communication system according to the related art.

FIG. 9 is a block diagram illustrating a configuration of a wireless base station and a communication adapter device according to the first embodiment.

FIG. 10 is a sequence diagram of a handover process in the first embodiment.

FIG. 11 is a sequence diagram of a channel switching process according to the first embodiment.

FIG. 12 is a block diagram showing a configuration of a wireless base station and a communication adapter device according to the second embodiment.

FIG. 13 is an explanatory diagram showing an example of data that is received by a wireless base station from a mobile terminal and transmitted to a public digital network in the second embodiment.

FIG. 14 is a block diagram showing a configuration of a data terminal according to the third embodiment.

FIG. 15 is a block diagram showing a configuration of a data terminal according to the fourth embodiment.

[Explanation of symbols]

Reference numeral 10: mobile terminal, 11, 12: radio base station, 13: interface for radio base station, 14: public digital network, 1
5: Digital fixed telephone, 16, 17: Data terminal, 1
8, 19: communication adapter device, 900: line control unit, 9
01, 902: buffer, 903: wireless signal transmission unit, 9
04: wireless signal receiving unit, 905: pattern data generating unit, 906: reception level / reception quality determining unit, 907: timer, 908: control unit, 909: line control unit, 910 ...
Pattern data detection unit, 911 ... data terminal control unit, 9
12: timer, 913: control unit, 1200: line control unit, 1201, 1202: buffer, 1203: wireless signal transmitting unit, 1204: wireless signal receiving unit, 1205: slot error detecting unit, 1206: slot error counting unit, 1
207: error slot replacement unit, 1208: reception level judgment unit, 1209: timer, 1210: control unit, 1211
... Line control unit, 1212 ... Pattern data detection unit, 12
13: pattern data counting unit, 1214: data terminal control unit, 1215: timer, 1216: control unit, 1400
... Communication processing unit, 1401 Information processing unit, 1402 Line control unit, 1403 Pattern data detection unit, 1404
Data transmission unit, 1405: Data reception unit, 1406: Timer, 1407: Control unit, 1500: Communication processing unit, 15
01 ... information processing unit, 1502 ... line control unit, 1503 ...
Pattern data detection unit, 1504: pattern data counting unit, 1505: data transmission unit, 1506: data reception unit, 1507: timer, 1508: control unit.

Continuing on the front page (72) Inventor Hitoshi Takanashi 3-19-2 Nishi Shinjuku, Shinjuku-ku, Tokyo Nippon Telegraph and Telephone Corporation (72) Inventor Hideo Matsuki 3- 19-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo Nippon Telegraph and Telephone Telephone Co., Ltd.

Claims (8)

[Claims] 1. A mobile terminal comprising: a plurality of mobile terminals; and a plurality of radio base stations for transmitting and receiving radio signals to and from these mobile terminals using a communication channel allocated to the mobile terminals. The radio base station performs a handover process of changing a radio base station that transmits and receives a radio signal to and from the mobile terminal when the reception quality of the radio signal is degraded from a reference value, and A digital mobile telephone network that executes any one of channel switching processes for changing the assignment of a communication channel used for transmitting and receiving a radio signal to and from a base station. A mobile radio data communication system for performing data communication between one data terminal and a second data terminal connected to the digital mobile telephone network via a digital wired line. Between the mobile terminal and the first data terminal; and
A communication adapter device interposed between the digital wired line and the second data terminal, for setting a data communication link on a communication path between the digital wired line and the second data terminal, wherein the mobile terminal performs the handover process and the channel switching From the start to the end of execution of any of the processes, the communication adapter device interposed between the first data terminal and the communication adapter device interposed between the data received from the radio base station as a radio signal. Instead, the wireless base station has pattern data transmitting means for repeatedly transmitting pattern data composed of a predetermined data pattern, and the radio base station starts executing any of the handover process and the channel switching process. Until the termination, the mobile terminal does not respond to the communication adapter device interposed with the second data terminal. Pattern data transmitting means for repeatedly transmitting the pattern data instead of the data received as a line signal, wherein the communication adapter device receives the data from the mobile terminal or the radio base station via the digital wired line. Pattern data detecting means for determining whether the received data is the pattern data, and execution of the handover processing or the channel switching processing is started when the pattern data detecting means detects the pattern data. And stopping the data transmission / reception operation to the first data terminal or the second data terminal when the determination means determines that the execution of the handover process or the channel switching process has started. Characterized by having data terminal control means for causing Line data communication system. 2. The mobile radio data communication system according to claim 1, wherein the mobile terminal and the radio base station start executing the handover process or the channel switching process before a predetermined time has elapsed. In response to the fact that the reception quality of the radio signal has been improved to the reference value or more, the execution of the started handover process or the channel switching process is stopped, and the determination unit starts executing the handover process or the channel switching process. If the pattern data detecting means detects data other than the pattern data before the same time as the predetermined time has elapsed since it was determined that the handover processing or the channel switching processing has been performed, the execution of the handover processing or the channel switching processing is stopped. The data terminal control means determines that the handover process or the channel When the determination means determines that the execution of the data switching process has been stopped, the first data terminal or the second data terminal restarts the data transmission / reception operation, and executes the handover process or the channel switching process. If the determination means determines that the communication has not been stopped, the data communication link is re-established on the communication path with the other communication adapter device, and if the data communication link has been successfully set, the first A mobile radio data communication system, wherein the data terminal or the second data terminal restarts a data transmission / reception operation. 3. The mobile radio data communication system according to claim 1, wherein said digital mobile telephone network employs a time division multiplexing system in which one communication channel is divided into a plurality of time slots and assigned to a plurality of mobile terminals. The mobile terminal and the radio base station perform the handover when the frequency at which an error occurs in data received as a radio signal using a time slot allocated to the mobile terminal reaches a reference value. Performing one of the processing and the channel switching processing, wherein the pattern data transmitting means of the mobile terminal generates an error in data received as a radio signal from the radio base station using the time slot. The communication adapter device interposed between the first data terminal and the first data terminal instead of the data. Pattern data transmitting means of the radio base station, when an error occurs in data received as a radio signal from the mobile terminal using the time slot, Instead of the data, the pattern data is transmitted to a communication adapter device interposed therebetween, and the determination unit determines that the pattern data detection unit does not detect the pattern data. Wherein the frequency of detecting the pattern data reaches the same reference value as the reference value, it is determined that the execution of the handover process or the channel switching process has been started. 4. The mobile radio data communication system according to claim 3, wherein said determination means is configured to determine whether the frequency at which the pattern data detection means has detected the pattern data does not reach the same reference value as the reference value.
When the number of times the pattern data detecting means continuously detects the pattern data reaches a predetermined number, it is determined that the execution of the handover process or the channel switching process has been started. Communications system. 5. A mobile terminal comprising: a plurality of mobile terminals; and a plurality of radio base stations for transmitting and receiving radio signals to and from these mobile terminals using a communication channel allocated to the mobile terminal. The radio base station performs a handover process of changing a radio base station that transmits and receives a radio signal to and from the mobile terminal when the reception quality of the radio signal is degraded from a reference value, and A digital mobile telephone network that executes any one of channel switching processes for changing the assignment of a communication channel used for transmitting and receiving a radio signal to and from a base station. A data communication link is set up on a communication path between one data terminal and a second data terminal connected to the digital mobile telephone network via a digital wired line. In the mobile radio data communication system for performing data communication, the mobile terminal performs the first data until the execution of any one of the handover process and the channel switching process is started and ends. Pattern data transmitting means for repeatedly transmitting, to the terminal, pattern data composed of a predetermined data pattern instead of data received as a radio signal from the radio base station, wherein the radio base station performs the handover process And from the start to the end of execution of any of the channel switching processes, to the second data terminal, in place of the data received as a radio signal from the mobile terminal, the pattern data Pattern data transmitting means for repeatedly transmitting the first data terminal and the second data terminal. A data terminal for determining whether data received from the mobile terminal or data received from the wireless base station via the digital wired line is the pattern data; and Means for judging that the execution of the handover process or the channel switching process has been started when the means detects the pattern data, wherein the judgment that the execution of the handover process or the channel switching process has started has been made. A mobile radio data communication system, wherein the data transmission / reception operation is stopped when the means determines. 6. The mobile radio data communication system according to claim 5, wherein the mobile terminal and the radio base station start executing the handover process or the channel switching process before a predetermined time has elapsed. In response to the fact that the reception quality of the radio signal has been improved to the reference value or more, the execution of the started handover process or the channel switching process is stopped, and the determination unit starts executing the handover process or the channel switching process. If the pattern data detecting means detects data other than the pattern data before the same time as the predetermined time has elapsed since it was determined that the handover processing or the channel switching processing has been performed, the execution of the handover processing or the channel switching processing is stopped. The first data terminal and the second data terminal determine that the hand When the determining means determines that the execution of the server process or the channel switching process has been stopped, the data transmitting / receiving operation is restarted, and the determining means determines that the execution of the handover process or the channel switching process has not been stopped. The mobile radio, characterized by re-establishing a data communication link on the communication path with the other data terminal when judging, and resuming the data transmission / reception operation if the data communication link is successfully established. Data communication system. 7. A mobile terminal comprising: a plurality of mobile terminals; and a plurality of radio base stations for transmitting and receiving radio signals between the mobile terminals by using a communication channel allocated to the mobile terminal. The radio base station performs a handover process of changing a radio base station that transmits and receives a radio signal to and from the mobile terminal when the reception quality of the radio signal is degraded from a reference value, and A digital mobile telephone network that executes any one of channel switching processes for changing the assignment of a communication channel used for transmitting and receiving a radio signal to and from a base station. A mobile radio data communication system for performing data communication between one data terminal and a second data terminal connected to the digital mobile telephone network via a digital wired line. Between the mobile terminal and the first data terminal; and
A communication adapter device interposed between the digital wired line and the second data terminal for setting a data communication link on a communication path between the digital wired line and the second data terminal. A pattern data detecting means for determining whether or not data received from the station via the digital wired line is the pattern data; and, when the pattern data detecting means detects the pattern data, the handover processing or the Determining means for determining that execution of the channel switching process has been started, and the first data terminal or the second data when the determining means determines that execution of the handover process or the channel switching process has started. Data terminal control means for causing the terminal to stop data transmission / reception operations. Communication adapter device. 8. The communication adapter device according to claim 7, wherein the mobile terminal and the radio base station start executing the handover process or the channel switching process before a predetermined time elapses. When the reception quality of the signal is improved to the reference value or more, the execution of the started handover process or the channel switching process is stopped, and the determination unit determines that the execution of the handover process or the channel switching process is started. If the pattern data detection unit detects data other than the pattern data before the same time as the predetermined time elapses after the determination, it is determined that the execution of the handover process or the channel switching process has been stopped. And the data terminal control means performs the handover process or the channel switching process. When the determining means determines that the execution of the data transfer is stopped, the first data terminal or the second data terminal restarts the data transmission / reception operation, and the execution of the handover process or the channel switching process is stopped. If the determining means determines that the data communication link has not been established, the data communication link is re-established on the communication path with the other communication adapter device. If the data communication link is successfully set, the first data terminal or A communication adapter device for causing the second data terminal to resume a data transmission / reception operation.