JPH08340308A - Communication system - Google Patents

Abstract

PURPOSE: To start communication while selecting a proper state automatically, to progress communication processing efficiently and to surely terminate the communication in the communication system employing a channel whose communication quality is unstable like mobile communication. CONSTITUTION: A resume function control section 12 stores data having already been sent/received till transmission reception of all data are finished and checks till which part of entire data have been sent/received and restarts data communication from the data part at which a channel is interrupted after re-connection when the channel is interrupted due to a deteriorated radio wave state on the way of communication. Furthermore, a radio wave strength detection section 13 monitors the radio wave strength to discriminate whether or not communication is enable, and raises a call instruction after awaiting the communication enable state when the communication is disable if a start request of data communication is received from the resume function control section 12. Moreover, a speed control section 14 decides an optimum data transmission speed based on the radio wave strength from the radio wave strength detection section 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a communication method suitable for a communication method using a line whose communication quality is not stable (for example, mobile communication in which a momentary disconnection of the line or frequent mixing of noise occurs).

[0002]

2. Description of the Related Art In communication using a mobile unit, there are restrictions that need not be taken into consideration in a wired line because of the use of wireless lines and the movement of communication stations. For example,
There are many restrictions in order to obtain sufficient communication quality, such as being in an area where communication is possible and whether the reception of radio waves is good.

However, in conventional mobile communication, basically,
The same communication processing as the wired line with stable quality is performed.

[0004]

Therefore, the conventional mobile communication has the following problems.

(1) Depending on the communication conditions such as the location of the communication subject and the radio wave condition, a line disconnection may occur during communication, or an obstacle may occur such that communication cannot be performed even if an attempt is made.

(2) In the case where data communication is performed between computers, if the line is disconnected during the communication, it is necessary to restart the communication process from the first data, so communication before the disconnection is wasteful. become.

(3) When the communication is reprocessed after disconnection of the line, it is not possible to know whether the line state is connectable unless the connection is made. Therefore, there is no choice but to try the connection.

(4) Unless a person constantly monitors whether communication conditions are good or bad and changes, it is impossible to determine the timing of communication. That is, it is impossible to automatically select a place and time with good communication conditions for communication.

(5) As a conventional technique relating to mobile communication, a protocol for monitoring the bit error rate during communication, decreasing the transmission rate when the bit error rate becomes high, and increasing the transmission rate when the bit error rate becomes low (MNP class 10). ) Is well known. However, since the bit error rate is monitored to determine the transmission rate, the communication efficiency is poor.

The present invention has been made on the basis of such a background, and an object thereof is automatically appropriate in a communication system using a line having unstable communication quality as represented by mobile communication. It is to provide a new improvement for selecting a proper state, starting communication, efficiently performing communication processing, and surely completing communication.

[0011]

The communication method according to the first aspect of the present invention is such that up to which processing step of the series of communication processing to be performed between the local station and the remote station has already been executed by the local station. And a process that the partner station recognizes when the communication line is disconnected and then reconnect during the course of a series of communication processes, and the process that the partner station recognizes. By notifying the stage from the partner station, means for matching the processing steps recognized by the own station and the partner station and means for restarting communication processing from the processing step subsequent to this matched processing step are provided. It is characterized by having.

A communication method using a wireless communication line according to the second aspect of the present invention monitors the radio field intensity of the wireless communication line and determines whether or not communication is possible, and a request to start communication, When the result of the determination is communicable at the time of receiving this request, and if communication is not possible, a means for starting communication after waiting until the determination result is changed to communicable is provided. Characterize.

A communication system using a wireless communication line according to the third aspect of the present invention controls a data transfer rate of communication according to a means for measuring a field intensity of the wireless communication line and the measured field intensity. And means.

In the communication method using the wireless communication line according to the fourth aspect of the present invention, when the communication line is disconnected in the middle of a series of communication processes and then reconnected, the communication process is executed from the already executed processing stage. Resume function means to restart, to monitor the radio field intensity of wireless communication line communication, determine whether communication is possible, measure the radio field intensity when communication is possible, and receive a request to start communication. If the result of the judgment is communicable at the time of receiving the request, and if communication is not possible, wait until the judgment result is changed to communicable, and then measure the automatic communication start means for starting communication. And a transfer rate control means for controlling the data transfer rate of communication according to the radio field intensity.

[0015]

In the communication system according to the first aspect of the present invention, it is recognized to which stage of a series of communication processes the own station has executed. For example, in the preferred embodiment, data transmission from the own station and data reception from the partner station are regarded as one processing stage, and the number of executed processing stages is counted and stored. In this way, when the line is disconnected during the communication process while always recognizing the executed processing stage, after the line is reconnected, the processing stage recognized by the own station at that time is sent to the partner station. Notice. At this time, the partner station also recognizes up to what processing stage it has executed, and therefore the partner station also notifies it of its own. As a result, the executed processing steps of the own station and the partner station can be matched with each other. For example, when both processing stages are different, the later stage is matched. In this way, after the processing steps of the own station and the partner station are matched, the communication processing is restarted from the processing step subsequent to this processing step.

As described above, when the communication is interrupted midway, the resume communication function for restarting the communication from the interrupted point is realized. This eliminates the need to redo the communication process from the beginning and enables efficient communication.

In the communication method using the wireless communication line according to the second aspect of the present invention, the radio field intensity of the line is monitored to determine whether or not communication is possible, and if communication is possible, a communication start request is made. Although the communication is immediately started, when the communication start request is received when the communication is impossible, the communication is automatically started after waiting until the state of the radio wave in which the communication is possible. As a result, if the user issues a communication start request at any time without being aware of whether communication is possible, the time when the communication is possible will be automatically selected and the communication will be executed reliably. become.

Further, by combining this automatic communication start function and the resume communication function described above, when the radio wave condition becomes communicable even if the line is disconnected during communication due to deterioration of the radio wave condition or the like. Since the communication is automatically restarted and the unexecuted communication processing is executed, the communication is surely completed to the end.

In the communication system using the wireless communication line according to the third aspect of the present invention, an appropriate data transfer rate is selected according to the radio wave intensity of the line. According to this method, compared to the conventional method of controlling the transfer rate by measuring the bit error rate, it is possible to immediately respond to the change of the radio wave condition, so that efficient communication becomes possible.

In the communication method using the wireless communication line according to the fourth aspect of the present invention, since the resume communication function, the automatic communication start function and the transfer speed control function are provided, the communication that is substantially error-free can be performed. It will be possible.

[0021]

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

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

The communication system shown in this figure has at least one terminal (a personal computer, a mobile terminal, etc.) as a mobile station, a server 2 as a fixed station (or a mobile station), and at least one wireless network for mobile stations. And a communication line network 3 included therein.
The terminal 1 and the server 2 can perform data communication by being connected via the line network 3. The terminal 1 and the server 2 respectively include communication devices 4 and 5 as communication interfaces with the line network 3.

The communication devices 4 and 5 are composed of, for example, a modem connected to the RS232C terminal or I / O terminal of the terminal 1 or the server 2 and a wireless transceiver connected to the modem. The wireless transceiver may be, for example, a mobile phone or PHS.
(Simple mobile phone) etc. can be used.

In this embodiment, the terminal 1 which is a mobile station is exclusively used.
Only the terminal 1 and the server 2 have the calling function, and the server 2 has only the incoming function but not the calling function. It should be possible to easily understand the embodiment having the calling function.

FIG. 2 is a block diagram of the terminal 1.

The terminal 1 comprises a communication control unit 11, a resume function control unit 12, a radio wave intensity detection unit 13, a speed control unit 14 and an application unit 15.

The communication control unit 11 controls the communication device 4 to transmit / receive data to / from the server 2. The application unit 15 executes data processing for the business that the terminal 1 is responsible for.

The resume function control unit 12 intervenes between the communication control unit 11 and the application unit 15 and manages the transmission / reception data a passed between the two, thereby resuming the resume communication function, that is, the interrupted communication. It realizes the function of starting communication from the interrupted position. In order to realize the resume communication function, the resume function control unit 12 has a function of holding the data a transmitted / received in one communication until the communication is completed, and when the communication is interrupted, the communication is resumed after that. In order to do so, it has a function of automatically issuing the call request d (or issuing the call request d in response to the call request b from the application unit 15). Details of the operation of the resume function control unit 12 will be described later.

The radio wave intensity detection unit 13 receives the signal c indicating the intensity (reception sensitivity) of the received radio wave from the communication control unit 11 and monitors the state of the wave to determine whether communication is possible or not. It realizes a radio wave automatic calling function, that is, a function for automatically calling when the radio wave state is communicable. More specifically, the radio field intensity detection unit 13
Periodically determines whether or not communication is possible based on the state of the received radio wave. When a call request d is received from the resume communication control unit 12, if communication is possible, on the other hand, if communication is not possible, Wait until communication becomes possible, and then call request d
In response to the request, the issue command e is sent to the communication control unit 11 to make a call.

Further, the radio field intensity detecting section 13 divides the radio field intensity into fine steps (for example, 5 steps) when communication is possible.
And has a function of notifying the speed control unit 14 of the step value f.

The speed controller 14 selects an appropriate data transfer rate according to the step value f of the field strength from the field strength detector 13 and sets the transfer rate h in the communication controller 11, thereby A transfer rate control function according to strength is realized.

FIG. 3 is a block diagram of the server 2.

The server 2 comprises a communication control unit 21, a resume function control unit 22, a speed control unit 23 and an application unit 24.

The communication control unit 21 controls the communication device 5 to transmit / receive data to / from the terminal 1. The application unit 24 executes data processing for the business that the server 2 is responsible for.

The resume function control unit 22 realizes the resume communication function by interposing between the communication control unit 21 and the application unit 24 and managing the transmission / reception data g passed between them. In order to realize the resume communication function, the resume function control unit 22 has a function of holding the data g transmitted / received in one communication until the communication is completed. Details of the operation of the resume function control unit 22 will be described later.

The speed control unit 23 receives the step value f of the radio wave intensity at the terminal 1 given from the terminal 1 through the communication control unit 21.
By selecting an appropriate transfer rate according to the above and setting this transfer rate j in the line control unit 21, a transfer rate control function according to the radio field intensity is realized.

With the above configuration, the resume communication function, the radio wave automatic transmission function and the transfer rate control function will be described in detail.

First, the resume communication function will be described. Resume communication function is data communication from the point where the line is disconnected after reconnection, when the line quality is deteriorated during the communication and the line is disconnected, or when the connection intentionally interrupts the communication. Say the function to start.

For example, in the flow of communication processing in which data is repeatedly transmitted and received as shown in FIG. 4, when the communication quality is deteriorated and the line is disconnected in the intermediate processing step (a), the terminal 1 and the server are then connected. When reconnection of No. 2 is performed, communication is restarted from the interrupted stage (a), and continuity of communication is maintained. In addition, even if the connection person himself / herself interrupts communication at a certain stage (b), if the connection is re-established, the stage (b)
Communication will be restarted from. Needless to say, in the case of connection type communication (telephone line, TCP / IP, etc.), it is necessary to reestablish the connection before restarting the communication.

FIG. 5 shows the resume function control unit 1 of the terminal 1 and the server 2 for realizing the resume communication function.
The processing flow of 2 and 22 is shown.

First, a call is made from the communication control unit 11 of the terminal 1, and when the communication control unit 21 of the server 2 responds to the incoming call, a line is connected between the two. After this line connection, first, the resume function control unit 12 on the calling side (hereinafter, simply referred to as "calling side") transmits its own resume processing data A to the resume function control unit 22 on the called side (hereinafter, simply "calling side"). (Called "caller") (S1).

Here, the resume processing data is control data used for synchronizing the communication processing stages of the calling side and the called side when starting communication, and the calling side after the line connection is made by the calling side. And what kind of communication processing is planned to be performed. Specifically, as shown in FIG.
Communication processing data ID of item number 1, number of processes of item number 2, item number 3
Processing number and FCS (frame check sequence) of item number 4 and the like.

The communication processing data ID of item No. 1 is a unique number assigned when the calling side generates the resume processing data so that the terminal 1 and the server 2 recognize the same resume processing data. is there. The number of processes in item No. 2 indicates the number of process stages included in the entire communication process when data transmission from the calling side and data transmission from the called side are defined as one process stage. The processing number of item No. 3 describes which processing step has already been completed among the number of processes shown in item No. 2, and it is set to zero when communication is started for the first time, or interrupted. When the communication is restarted, the number of processed stages at the time of interruption is set.

This resume processing data is initially generated by the calling side and is stored in the erasable non-volatile memory of the calling side, is transmitted to the called side as in step S1 above, and then As described above, it is stored in the erasable non-volatile memory of the called side.

Now, referring again to FIG. 5, on the called side,
When the resume processing data A is received from the calling side (S2), it is first checked whether or not there is the resume processing data B held by itself (S3). It should be noted that the case where there is resume processing data B on the called side is only when there is communication that has been interrupted and has not been restarted yet, and communication has not been performed even once or past communication has been completed. If so, there is no resume processing data B on the called side at the stage of step S3.

As a result of the check in step S3, if the called party does not have the resume processing data B, the called party copies and saves the received resume processing data A as it is as the called party's resume processing data B. Then, the resume processing data B is returned to the calling side (S5).

On the other hand, as a result of the step S3, if there is resume processing data B on the called side, then it is checked whether or not the communication processing data IDs of the resume processing data A and B match (S4). ). As a result, the matching ID
If there is not, the called side continues the received resume process data A as it is on the receive side resume process data B.
Then, the resume processing data B is directly returned to the calling side (S5).

Further, as a result of step S4, the matching ID
If the resume process data B of No. 1 exists, the process numbers of the received resume process data A and the existing resume process data B are compared (S6), and the resume process data having the smaller process number is received. It is saved as the resume processing data B of (S7) and is returned to the calling side.

The calling side receives the resume processing data B from the called side (S8), and both resume processing data A,
After confirming that the IDs of B match (S9),
Next, the process numbers of the resume process data A and B are compared (S10), and if the process number of the resume process data B is smaller than the process number of the resume process data A, the resume process data B is called. Side resume processing data A is copied and saved (S1)
1). If the process number of the resume process data B is larger than the process number of the resume process data A, it is regarded as an error.

Through the above processing, both the calling side (terminal 1) and the called side (server 2) synchronize the processing number with the processing stage on the side where the processing progress is delayed.

After matching the processing numbers in this way,
Transmission and reception of net communication data is started from the processing number. After that, every time one processing step of the communication consisting of the transmission from the calling side and the transmission from the called side is completed, the calling side and the called side respectively set the processing number of the resume processing data to 1
Increase by one.

Further, as shown in FIG. 7, both the calling side and the called side store the contents of the data which have already been transmitted and received in the communication in the erasable nonvolatile memory. This stored data content is the same as the above-mentioned step S1 when the communication is interrupted and the communication is restarted.
When it is necessary to return the processing number to the value on the delayed side in order to match the processing steps in S11 to S11 (for example, S
7, S11), and is used to resend data from the returned processing number.

As described above, even if the communication is interrupted, it is possible to continue the communication from the interrupted position.
When the transmission and reception for the number of processes of item No. 2 in FIG. 6 are all completed, all the data shown in FIGS. 6 and 7 relating to the communication stored in the calling side and the called side are erased.

FIG. 8 shows a mode of communication performed by the above-described resume communication function. The transmission data n01 and n02 at the processing stage T0 show the synchronization processing by transmitting and receiving the resume processing data shown in FIG. Transmission data n11, n12, n21 of the processing stages T1, T2 ...
n22 ... indicates transmission / reception of net communication data.

Now, processing step T for sending the net data
1, T2 ..., the individual data n11, n12, n2
.., n22 ... Are prepared as a single file in the terminal 1 and the server 2 and are transmitted. The resume function for sending a single file is
ZMODEM, which is now widely used in personal computer communication,
It is supported by the QUICK-VAN protocol or the like. Therefore, if each transmission data is transmitted as a single file as described above, if the line disconnection occurs during transmission of a certain file (data), the resume function of the above-mentioned known protocol can be diverted. Thus, the remaining portion of the file can be transmitted from the interrupted portion of the file, and the subsequent untransmitted file can be continuously transmitted by the resume function described in detail in FIG.

Next, the radio wave monitoring automatic transmission communication function of this embodiment will be described.

The radio wave monitoring automatic transmission communication function means that even if the mobile station is in a place where data communication is not possible, if a request for data communication processing is issued, data communication is automatically started when the environment is changed to enable communication. And say the function to complete.

For example, as shown in FIG. 9, it is assumed that radio waves cannot reach in area B and data communication cannot be performed. When the application unit 15 shown in FIG. 2 issues a request for data communication (call request b) when the terminal 1 is in the area B, the resume function control unit 12 which receives the call request b
Sends a call request d to the radio field intensity detector 13. However, the radio wave intensity detection unit d determines that communication is impossible and puts the call request d on standby. After that, when the terminal 1 moves and enters the area A where radio waves of sufficient intensity reach, the radio wave intensity detection unit 13 recognizes that communication is possible and accepts the call request d that was waiting and communicates the call command e. It is sent to the control unit 11. After that, the resume function controller 12 operates to perform data communication as described above.

Further, as shown in FIG. 10A, there are incommunicable areas X and Y between communicable areas A, B and C, and terminal 1 is moving from communicable area A to C. During this period, it is assumed that a call request is issued within the communicable area A.

In this case, the radio field intensity detection unit 13 shown in FIG. 2 immediately issues the call instruction e in response to the call request d in the communicable area A, and data communication is started. Then, when the terminal 1 enters the incommunicable area X, the communication is interrupted. Then, the resume function value control unit 12 automatically issues the call request d again, and the radio field intensity detection unit 13 that receives the call request waits until the terminal 1 enters the next communicable area B and then issues the call command e. The communication is restarted. When restarting the communication, the resume function control unit 12 operates as described above to start the data communication from the interrupted point.

In this way, as shown in FIG. 10B, only in the communicable areas A, B and C, the communication is automatically selected and the communication is executed.

Next, the transfer rate control function according to the radio field intensity in this embodiment will be described.

FIG. 11 shows an example of a correspondence table of the radio wave intensity and the data transfer rate, which are provided in the speed control units 14 and 23 of the terminal 1 and the server 2, respectively.

As shown in FIG. 11, the radio wave intensity is classified into 5 levels of 1 to 5, and when the intensity level is 1, the transfer rate is 300 bps, when it is 2, 1200 bps, and when it is 3, it is 2.
400 bps, 4 at 4800 bps, 5 at 96
The data transfer rate is determined as 00 pbs.

The speed control unit 14 of the terminal 1 receives the step value f of the radio field intensity from the radio field intensity detection unit 13 periodically when the radio field intensity is in the communicable state, and the corresponding data is obtained from the table shown in FIG. The transfer rate is selected and set in the communication control unit 11. When making a call, the communication control unit 11 notifies the server 2 of the radio wave intensity level value corresponding to the currently set data transfer rate.

In the server 2, at the time of an incoming call, the speed control unit 23 receives the radio wave intensity level value i notified from the terminal 1, selects the corresponding data transfer speed from the table shown in FIG. Set to.

After the data transfer rate suitable for the radio field intensity in the terminal 1 which is a mobile station is set in the communication control sections 11 and 21 of the terminal 1 and the server 2 as described above, both communication control sections 11 and 21 Data communication is started at the data transfer rate.

When the radio wave intensity level changes due to movement of the terminal 1 during data communication, the speed control unit 14 of the terminal 1 selects a new data transfer speed and sets it in the communication control unit 11. At the same time, the server 2 is notified of the radio wave intensity step value corresponding to the new data transfer rate.
In the server 2, the speed control unit 23 sets a new data transfer speed in the communication control unit 21 based on the notified step value. In this way, after the new transfer rate is set for both the terminal 1 and the server 2, both perform the subsequent data communication at the new transfer rate.

By thus controlling the transfer rate according to the radio field intensity, it is possible to respond appropriately to changes in the radio wave state, as compared with the conventional case where the bit error rate is measured and the transfer rate is controlled. Since the transfer speed can be obtained, high communication efficiency can be obtained as a whole.

Further, in addition to controlling the transfer rate by the radio wave intensity, it is possible to measure the bit error rate and further adjust the transfer rate to obtain a more optimal transfer rate.

The above-described resume communication function, radio wave intensity monitoring automatic call function, and transfer rate control function based on radio wave intensity enable substantially error-free mobile communication.

[0073]

As described above, according to the present invention,
With the resume communication function, the communication processing can be efficiently advanced, and the communication can be surely completed. Further, the radio wave automatic calling function can automatically select an appropriate state and start communication. Further, the communication speed can be efficiently advanced by the transfer rate control function based on the radio field intensity.

[Brief description of drawings]

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

FIG. 2 is a block diagram of the terminal shown in FIG.

FIG. 3 is a block diagram of the server shown in FIG.

FIG. 4 is an explanatory diagram of a resume communication function.

FIG. 5 is a processing flowchart for realizing a resume communication function.

FIG. 6 is an explanatory diagram showing an example of a format of resume communication processing data.

FIG. 7 is an explanatory diagram showing an example of a mode of storing communication data.

FIG. 8 is an explanatory diagram showing an example of resume communication processing.

FIG. 9 is an explanatory diagram of a radio wave monitoring automatic transmission communication function when moving from a communication impossible area to a communication area.

FIG. 10 is an explanatory diagram of a radio wave monitoring automatic transmission communication function when the communicable area and the communicable area are alternately moved.

FIG. 11 is an explanatory diagram showing a correspondence table of radio field intensity and transfer rate.

[Explanation of symbols]

 1 Terminal 2 Server 3 Circuit Network 4, 5 Communication Device 11 Communication Control Unit 12, 22 Resume Function Control Unit 13 Radio Field Strength Detection Unit 14, 23 Speed Control Unit 15, 24 Application Unit

Claims (4)

[Claims] 1. A means for recognizing, up to which processing step, a series of communication processes to be performed between the own station and the partner station, which has been executed in the own station, and a middle of the series of communication processes. When you reconnect after disconnecting the communication line with, notify the other station of the processing stage you are aware of,
And means for matching the processing steps recognized by the partner station with the partner station by notifying the processing step recognized by the partner station, and a processing step subsequent to the matched processing step. And a means for restarting communication processing. 2. A means for monitoring the radio field intensity of a wireless communication line to determine whether communication is possible, and a request for starting communication, and when the request is received, the result of the determination can be communicated. A communication system using a wireless communication line, characterized in that it further comprises a means for starting communication immediately or, if communication is not possible, waiting until the determination result changes to communicable. 3. A wireless communication line comprising: a unit for measuring a field intensity of a wireless communication line; and a unit for controlling a data transfer rate of communication according to the measured field intensity. The communication method used. 4. A resume function means for restarting the communication processing from the processing stage already executed when the line is disconnected and reconnected during the series of communication processing, and the radio field intensity of the wireless communication line communication is monitored. And whether or not communication is possible, and means for measuring the radio field intensity when communication is possible, and a request to start communication is received, and if the result of the above determination at the time of receiving this request is communication, immediately. If communication is not possible, an automatic communication start unit that starts communication after waiting for the determination result to be changed to communication, and a transfer that controls the data transfer rate of communication according to the measured radio field intensity A communication system using a wireless communication line, characterized by comprising: speed control means.