JP2001078247A - Communication channel allocation method and apparatus - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To efficiently transmit data using a gap of a voice call. An available communication channel is allocated to a connection request call regardless of the call type. When a call for a new connection request occurs when all communication channels are in use, the communication content of each channel is monitored, and communication with a lower priority than the priority of the call for the new connection request is performed. The current call is stopped, and the channel used by the call is assigned to the call for the new connection request. Further, the data of the stopped call up to that point is stored, and the communication is resumed. If a free channel occurs and there is a call that has stopped the communication, the free channel is allocated to one of the calls that have stopped the communication, and the communication of the call is restarted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication channel allocation method and apparatus in a communication system such as a mobile communication system in which a plurality of users use a common communication channel.

[0002]

2. Description of the Related Art Generally, requirements for transmission quality and transmission delay time differ depending on communication contents. Voice communication requires immediacy of communication and requires a short transmission delay time. On the other hand, in data transmission, transmission delay time hardly matters, but high transmission quality is required. As a communication channel allocating method for realizing such a multi-rate transmission system that integrates data and voice and enables transmission in the same system, a method of allocating a voice call and a data call to dedicated communication channels, respectively, It is known to assign calls and data calls to a common communication channel.

First, a method of assigning a voice call and a data call to dedicated communication channels will be described. In this method, if all of the dedicated communication channels are in use for both voice calls and data calls, even if the other communication channel has a vacancy, no channel is allocated and a call loss occurs. FIG. 4 shows a communication channel TCH and a control channel C over time when a voice call and a data call are respectively assigned to dedicated communication channels.
It is a figure showing the state of CH. Here, the communication channel TCH
Is composed of three channels, two voice channels CH1, CH2 and a data channel CH3.

[0004] As shown in the figure, at times t0, t1, and t2, a voice call request (a08) and a data call request (a0) are made on the control channel CCH.
9), assuming that a voice call request (a10) occurs, the dedicated communication channel CH1 is assigned as voice # 1 (a01), CH3 as data # 1 (a05), and CH2 as voice # 2 (a03). Communication is performed. Then, it is assumed that a voice call request (a11) occurs on the control channel CCH at time t3 after the data channel CH3 is released. At this time, since the voice channels CH1 and CH2 of the communication channel TCH have already been allocated voice # 1 and voice # 2, this request (a11) is a call loss. Therefore, as shown by (a15) in the figure, no channel is allocated even if the request is repeated again. Then, at time t4 after the release of the audio channel CH2, the re-request (a15) is assigned to the CH2 as audio # 3 (a04) and communication is performed.

If a data call request (a12) and a voice call request (a13) occur on the control channel CCH at times t5 and t6, data # 2 ( a06), communication is performed with voice # 4 (a02) assigned. Then, at time t7 after the voice # 3 (a04) of CH2 is released, even if a data call request (a14) occurs on the control channel CCH, at this time, the data channel CH3 of the communication channel TCH is Since # 2 (a06) is assigned, this request becomes a call loss. Request for this data call (a14)
Is not allocated even if the re-request (a16) is repeated, and is allocated as data # 3 (a07) at time t8 after the data # 2 (a06) of CH3 is released. As described above, the method of allocating a voice call and a data call to dedicated communication channels is based on the assumption that all dedicated communication channels are in use in a voice call or a data call even if the other communication channel is free. Will not be assigned, resulting in a call loss.

As a method for solving the problem that communication cannot be performed without being allocated even if such a channel has a space, a method of allocating voice communication and data communication to a common communication channel is known. This method will be described with reference to FIG. 5 showing states of the communication channel TCH and the control channel CCH over time. Here, the communication channel TCH includes three common channels CH1, CH2, and CH3.

First, at time t0, t1, t2, the control channel CCH
Then, assuming that a voice call request (b08), a data call request (b09), and a voice call request (b10) are generated, voice # 1 (b01) is assigned to CH1 of the communication channel, and data # 1 is assigned to CH3. (b05), communication is performed by assigning it to CH2 as voice # 2 (b03). Then, when a voice call request (b11) occurs on the control channel CCH at time t3 after the release of CH3, an empty communication channel CH3 is allocated to this request, and communication is performed as voice # 3 (b06). Done. When a data call request (b12) occurs on the control channel CCH at time t4 after the release of CH2 and CH3, communication is performed by allocating the data call to the free communication channel CH3 as data # 2 (b07). Then, when a voice call request (b13) occurs on the control channel CCH at time t5 after the release of CH1, the communication is performed by allocating the voice call to the free communication channel CH1 as voice # 4 (b02). Thereafter, when a data call request (b14) occurs on the control channel CCH at time t6, communication is performed by assigning the data call # 3 (b04) to the vacant communication channel CH2. As described above, according to the method of allocating a common communication channel to the voice call and the data call, if there is a vacant channel, it is possible to perform communication by allocating a channel to any of the calls. Such problems can be solved. However, when the number of calls increases, a call loss occurs, which is a serious problem particularly for voice calls that require immediacy.

Therefore, CDPD (Cellular Digital Pack)
et Data), a common communication channel allocation method for giving priority to voice calls is known. FIG. 6 shows the communication channel TCH and the control channel C over time in the case of the common communication channel assignment method for giving priority to this voice call.
It is a figure showing the state of CH. Here, it is assumed that the communication channel TCH includes three channels, CH1, CH2, and CH3. Further, in this method, data is allocated to a communication channel having a free voice. Further, if a voice call and a data call are present during all-channel communication, a voice call requiring immediacy can be preferentially assigned to a channel assigned to a data call. In this case, a data call that surrenders a channel during communication results in communication failure, that is, a call loss.

In FIG. 6, at time t0, t1, t2, a voice call request (b40), a data call request (b41),
Assuming that a voice call request (b42) occurs, voice # 1 (b31) is assigned to CH1 of the communication channel, data # 1 (b37), CH
2 is assigned as voice # 2 (b34) and communication is performed. Request for a voice call on the control channel CCH at time t3 during that time (b43)
Is generated. At this time, audio # 1, audio # 2, and data # 1 are allocated to all the channels CH1, CH2, and CH3 of the communication channel TCH. Here, since the channel is preferentially assigned to the voice call, the communication of data # 1 of CH3 in communication is stopped (forced termination). as a result,
Data # 1 is a call loss. Therefore, the transmitting side and the receiving side performing the communication of the data # 1 regard the communication as failure,
The receiving side discards the data so far, and the transmitting side makes a request for data transmission again. Then, voice # 3 (b38) is allocated to CH3 released in this way. Also, the data # 1 that has been once blocked will be lost each time the re-request (b47) is repeated until an empty channel is created. Then, at time t4, when CH2 is released,
The re-request (b47) is allocated to CH2 as data # 1r1 (b35) and communication is performed. At this time, data # 1 is again communicated from the beginning.

[0010] Further, it is assumed that a data call request (b44) occurs at time t5 on the control channel CCH. At this time, since communication is allocated to all the communication channels TCH, this request (b44) causes a call loss. Even if re-request (b48) is repeated until an empty channel is created, a call is lost each time. Then, at time t6, when CH1 is released, a re-request (b4
8) is allocated to CH1 as data # 2 (b32) and communication is performed. Assuming that a voice call request (b45) occurs at time t7, since channel CH3 is empty at this time, voice # 4
Assigned as A request for a voice call at a later time t8
Assume that (b46) has occurred. At this time, data # 2, data # 1r1, and audio # 4 are allocated to all the channels CH1, CH2, and CH3 of the communication channel TCH. As described above, since the channel is preferentially assigned to the voice call, the data # 1r1 of the communicating CH2 is stopped. As a result, the data # 1r1 becomes a call loss. The request (b46) is assigned to the released CH2 as voice # 5 (b36). The data # 1r1 that has lost the call again will be lost each time the re-request (b49) is repeated until an empty channel is created. When CH1 is released at time t9, the re-request (b49) is allocated to CH1 as data # 1r2 (b33) and communication is performed. As described above, according to the common communication channel method in which the voice call is prioritized, it is possible to avoid a call loss of the voice call. However, a data call is lost every time a communication channel is surrendered.

[0011]

In recent years, with the diversification of uses of mobile communication, further effective use of frequency resources has become an issue, and a multi-rate transmission system is an essential technical problem to solve this issue. It is one of. However, the above-mentioned conventional communication channel assignment method has the following problems. Problem A: In the method of allocating the voice call and the data call to the dedicated communication channels, the voice call and the data call cannot be allocated unless the dedicated communication channels are free. Therefore, if the determined communication channel is not empty, communication cannot be performed even if the other communication channel is empty. Problem B: In the common communication channel allocating method for giving priority to voice calls, a priority is given to a voice call with immediacy and a communication channel is allocated. Call loss. Therefore, the conventional communication channel allocation method described above cannot efficiently transmit diversified communication contents.

Therefore, the present invention makes it possible to use frequency resources more effectively than conventional communication channel allocation methods by utilizing the features of voice calls and data calls, and to communicate more information. It is an object to provide a communication channel allocation method and apparatus.

[0013]

To achieve the above object, a communication channel allocating method according to the present invention is a communication channel allocating method in a communication system in which a plurality of communication stations use a common communication channel, When a call for a new connection request occurs while all communication channels are in use, a lower priority than the priority of the call for the new connection request among calls performing communication in the all communication channels. If there is a call with a lower priority, the communication of any one of the lower priority calls is stopped, the communication channel used by the call is assigned to the call of the new connection request, and an empty channel is generated. In this case, when there is a call in which the communication is suspended, the empty channel is allocated to one of the calls in which the communication is suspended, and the communication of the call is resumed. The priority of voice communication is higher than that of data communication, facsimile communication, image communication or voice mail communication. Further, when stopping the communication,
The previous communication contents are not discarded.

Furthermore, a communication channel allocating apparatus according to the present invention is a communication channel allocating apparatus in a communication system in which a plurality of communication stations use a common communication channel, wherein a new connection is established when all communication channels are in use. When a request call occurs, if there is a call having a lower priority than the priority of the call of the new connection request among the calls performing communication in the all communication channels, the priority is set to the priority. Means for stopping communication of any one of the low calls, and allocating the communication channel used by the call to the call of the new connection request;
Means for allocating the free channel to one of the calls for which communication has been stopped and resuming the communication of the call when there is a call for which the communication is stopped when a free channel occurs. And

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A communication channel allocating method (voice call space communication channel allocating method) and apparatus according to the present invention will be described below with reference to FIGS. According to the communication channel allocating method of the present invention, it is possible to efficiently perform data communication by cutting a gap between voice calls. In the communication channel allocating method of the present invention, an empty communication channel is allocated regardless of the call type. That is, any communication channel can be allocated to a voice call and a data call, as in the above-described common communication channel allocation method. Here, the data call includes computer data communication, facsimile communication, image communication, voice mail communication, and the like. Further, similarly to the method shown in FIG.
Voice calls are prioritized over data calls. That is, when all the channels are in use, the communication channel assigned to the data call is preferentially assigned to a voice call requiring immediacy. At this time, in the present invention, a data call in which a channel is released to a voice call during communication is put on hold (stopped) until the communication channel becomes available. Communication is restarted. Stopping this data communication and waiting for it to resume,
In the present invention, it will be referred to as waiting. During this waiting time, the receiving side stores the data in the buffer without discarding the data. After resuming, the sender sends only the unsent portion. Even if the data is divided into a plurality of parts and transmitted, the receiving side collectively demodulates them.

FIG. 1 is a block diagram showing a main configuration of a communication system to which a communication channel assignment method according to the present invention is applied. Although the communication system to which the communication channel assignment method of the present invention is applied is not particularly limited, here, communication between a mobile station and a base station or communication for performing direct communication between mobile stations under the control of the base station is described. This will be described by taking a system as an example. In FIG. 1, 10 is a base station, and 20 is a mobile station. In the base station 10, a transmission / reception unit 12 transmits a signal to and from the mobile station 20 via the antenna 11. Reference numeral 13 denotes a request call type determination for determining whether the call type is a voice call or a data call from a call occurrence or standby connection request reception signal (d01) from the reception unit of the transmission / reception unit 12. The unit 14 is a channel monitoring control unit that monitors the states of the communication channel TCH and the control channel CCH and controls them. This channel monitoring control unit 14
Thus, in response to the occurrence of a call or a standby connection request, communication channel allocation control is performed in accordance with the use state of the communication channel, and a communication channel allocation instruction (d
02), call loss (d03), communication stop status confirmation / waiting command (d04),
Various commands such as a waiting command (d05) are input to the transmission / reception unit 12 and transmitted to a corresponding mobile station or the like. Also, 15
Is a buffer memory in which data during communication corresponding to a data call is stored during standby, and allows data to be continuously transmitted and received before communication is stopped without restarting communication when communication is resumed. .

In the mobile station 20, reference numeral 21 denotes a mobile station antenna, and reference numeral 22 denotes a transmitting / receiving unit. When a call is generated, or when there is a waiting data call and there is a waiting connection request, a control channel is transmitted from the transmitting unit in the transmitting / receiving unit 22.
A call request or a standby connection request (d10) is transmitted via the CCH. The above-mentioned various commands from the channel monitoring control unit 14 of the base station 10 are transmitted to the mobile station transmitting / receiving unit 2.
2, the received commands (d11) to (d1)
Processing corresponding to 4) is performed. Reference numeral 23 denotes a buffer for storing the data being communicated when the data being communicated is stopped. That is, when the mobile station 20 is a station that transmits data, the data being communicated is stored in the buffer 23 so that data that has not been transmitted can be transmitted when communication is resumed. . When the station is a data receiving station, the data received up to the stop is stored in this buffer 23, and the data is combined with the subsequent data received after the communication is restarted so that the data can be decoded.

FIG. 2 is a flowchart showing the flow of processing in such a communication channel assignment method of the present invention. This processing is mainly performed by the request call type determination unit 13.
And is executed by the channel monitoring control unit 14. First, when a call or a standby connection request (d01) is generated (step S1), the use state of the communication channel is checked (step S2). As a result, if there is a free channel, a communication channel allocation command (d02) is output, and a free channel is allocated to the call (voice call, data call or standby connection request) to start communication (step S3). ). At this time, if a communication channel is allocated to the standby connection request, the transmitting side transmits data subsequent to the transmission data before the stop. On the receiving side, decoding is performed by combining the received data before the stop stored in the buffer (15 or 23) with the data received in the current communication.

On the other hand, if all the channels are in use and there are no available channels, the flow advances to step S4 to check the communication contents of each communication channel. As a result, if there is a data call that is currently using the communication channel, that is, if there is a communication channel that is being used for data communication, the process proceeds to step S5. Call generated in S1 (or request for standby connection)
Is a voice call or a data call.

If the result of determination in step S5 is that the call is a voice call, the flow advances to step S6 to stop one of the data calls currently being communicated. That is, a communication stop state confirmation / waiting command (d04) is transmitted to the transmitting station and the receiving station that are communicating the data call, and the data communication is stopped. This communication stop state confirmation / waiting instruction (d13)
The transmitting station that has received the data stops transmitting the data.
At this time, the transmitted block and the untransmitted block of the transmission data are stored. When transmission data is input from an information source, the data is stored in the buffer (15 or 23). On the other hand, the receiving station receiving the communication stop state confirmation / waiting instruction (d13) stores the received data up to that time in the buffer (15 or 23).
Store in and save. That is, this data call is in a waiting state (step S7). At this time, the transmitting station performing the data communication transmits a connection request (waiting connection request) to the control channel CCH at predetermined time intervals, for example.

The voice call is allocated to the communication channel released in this way, and voice communication is started (step S3). That is, the communication channel assignment command (d02) is transmitted to the transmitting / receiving station of the voice call. Further, as a result of the determination in step S5, when the generated call is a data call (or a standby connection request), a standby command (d05) is sent to the station that generated the call, and The call is set in a waiting state (step S7).

On the other hand, if it is determined in step S4 that all channels are communicating voice calls, the flow advances to step S8 to determine the type of the generated call. As a result, if the generated call is a data call or the standby connection request, the process proceeds to step S7, where the standby command (d05) is transmitted to the station that has generated the call, and the standby command is transmitted. The time state is set (step S7). On the other hand, if the call is a voice call, a call loss command (d03) is sent out, and the call is regarded as a call loss (step S9). Then, the process returns to step S1 to wait for a call again. In FIG. 2, hatched portions (in steps S3 and S7) indicate portions that have been lost or discarded in the conventional communication channel assignment method. As described above, according to the communication channel allocation method of the present invention, in the common communication channel allocation method in which voice calls are prioritized, data transmitted before forced termination is not wasted, thereby improving efficiency. A communication channel assignment method becomes possible.

Next, the operation of the system to which the communication channel allocating method of the present invention is applied will be described with reference to FIG. 3 showing the state of the communication channel TCH and the control channel CCH over time. Here, it is assumed that the communication channel TCH includes three channels, CH1, CH2, and CH3. First, at times t0, t1, and t2, suppose that a voice call request (c10), a data call request (c11), and a voice call request (c12) occur on the control channel CCH. # 1 (c01), data on CH3 #
1-1 (c07), communication is performed by allocating the voice # 2 (c04) to CH2.

Then, at the time t3 during that time, the control channel
It is assumed that a voice call request (c13) has occurred on the CCH. At this time,
Audio # 1 for all channels CH1, CH2 and CH3 of the communication channel TCH
(c01), voice # 2 (c04), and data # 1-1 (c07). Since a channel is preferentially assigned to a voice call, communication of data # 1-1 (c07) of CH3 during communication is stopped, and the above-described waiting state is set. That is, the communication stop state confirmation / standby command (d04) is transmitted to the transmitting / receiving station of the data # 1-1 to stop the communication of the data # 1-1.
The communication channel CH3 is released. After CH3 is released,
The communication channel assignment command (d02) is transmitted to the transmitting / receiving station for the voice call (c13), and voice # 3 (c08) is allocated to CH3. At this time, as described above, the contents of the data # 1-1 (c07) communicated so far are stored in the buffer (1) of the receiving station.
5 or 23). Further, the transmitting station of the data call set to the waiting state cannot allocate a channel even if re-request (c17) is repeated until a free channel is created, and the station is set to the waiting state each time.

Then, at time t4, when voice # 2 releases CH2, the waiting data call re-request (c17) is assigned to CH2 as data # 1-2 (c05), and communication is resumed.
Also, at time t5, a request for a data call on the control channel CCH (c14)
Occurs, the request (c14) is in the standby state (d03) because communication is allocated to all the communication channels TCH. And re-request until an empty channel is created (c18)
Is repeated, the channel is not allocated, and it becomes waiting every time. When the voice # 1 (c01) of CH1 is released at time t6, the re-request for the waiting data call (c18) is transmitted to CH1.
Communication is performed as assigned as # 2 (c02).

The request for the voice call generated at time t7 (c1
5) is allocated to channel CH3 because it is empty. It is assumed that a voice call request (c16) occurs at the subsequent time t8. At this time, all channels CH1, CH of the communication channel TCH
2, data # 2, data # 1-2, and voice # 4 are assigned to CH3. Here, since the channel is preferentially allocated to the voice call, for example, the data # 1-2 of the currently communicating CH2 is stopped and waited, and the CH2 is released, as described above. At this time, the contents of the data # 1-2 communicated so far are stored in the buffer. After CH2 is released, voice # 5 on CH2 (c06)
Assign. The data # 1-2, which has been waiting again, is not assigned a channel even if the re-request (c19) is repeated until a free channel is created, and the data # 1-2 becomes waiting each time. At time t9, the data call re-request (c19), which had been waiting for data # 2 (c02) to release CH1 due to the end of the communication, sent data # 1-3 (c
03) and communication is performed. When the communication of the data # 1-3 is completed, the data # 1-1, the data # 1-2, and the data # 1-3 stored in the buffer are collectively handled as the data # 1 on the receiving side.

In the above description, only two types of calls, a voice call and a data call, have been described, and it has been described that there are only two types of priorities. Can be applied. In this case, the call having the lowest priority among the calls in communication is made to wait, and when an idle channel is created, the call having the highest priority among the waiting calls is made the highest priority. Try to allocate a free channel. Also, in the above description, the waiting data call is described as repeating the re-request. However, when the channel monitoring control unit 14 detects the occurrence of an idle communication channel, The communication channel assignment command (d02) may be transmitted to a station having

[0028]

As described above, according to the communication channel allocating method and apparatus of the present invention, priority is given to channel allocation for voice calls requiring immediacy, and data calls during communication are stopped. , Because we have a voice call there,
It is possible to prevent a voice call delay and call loss. Further, since the data call is made to wait and divided and transmitted, it is possible to transmit a large amount of data using the gap of the voice call, and it is possible to improve the channel use efficiency.

[Brief description of the drawings]

FIG. 1 is a diagram showing a main configuration of a system to which a communication channel assignment method according to the present invention is applied.

FIG. 2 is a flowchart illustrating a communication channel assignment method according to the present invention.

FIG. 3 is a diagram for explaining states of a communication channel and a control channel when the communication channel allocating method of the present invention is applied.

FIG. 4 is a diagram for explaining a conventional communication channel assignment method.

FIG. 5 is a diagram for explaining a conventional common communication channel assignment method.

FIG. 6 is a diagram for explaining a conventional method of allocating a common communication channel that prioritizes a voice call.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Base station 11, 21 Antenna 12, 22 Transmission / reception part 13 Requested call type determination part 14 Channel monitoring control part 15, 23 Buffer 20 Mobile station

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[Procedure amendment]

[Submission date] April 28, 2000 (200.4.2
8)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction contents]

[0013]

To achieve the above object, a communication channel allocating method according to the present invention is a communication channel allocating method in a communication system in which a plurality of communication stations use a common communication channel, If a call for a new connection request occurs when the communication channel has a vacancy,
A free communication channel is allocated to the call, and if a call for a new connection request occurs while all communication channels are being used for voice communication, if the call is a voice call, it is regarded as a call loss, and if it is a data call, If a call for a new connection request occurs when all communication channels are in use and there is a communication channel in use for data communication, if the call is a voice call, it is used for the data communication. Data communication using any one of the communication channels in the middle is stopped and put into a standby state, and the communication channel is assigned to the generated voice call, and the generated call is a data call. If so, the call is placed in a waiting state, and when the data call is placed in a waiting state, the transmitting side of the call stores the transmitted data in a buffer memory so that untransmitted data can be identified and receives the data. The data stored in the buffer memory is stored in the buffer memory up to the time when the standby state is set, and the idle communication for the data call in the standby state when the communication channel becomes available. Channels are allocated so that communication of data subsequent to the data communicated up to the time when the standby state is established is resumed. The data call is a call for computer data communication, facsimile communication, image communication, or voice mail communication.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction contents]

Further, the communication apparatus according to the present invention is a communication apparatus used in a communication system in which a plurality of communication stations use a common communication channel, comprising: a transmission / reception means; A determination unit, a channel monitoring control unit that monitors and controls the states of the communication channel and the control channel, and a buffer memory that stores data during communication corresponding to the data call; When a call for a new connection request occurs when the communication channel has a vacancy, an empty communication channel is allocated to the call, and a call for the new connection request is made when all the communication channels are being used for voice communication. If a call is made, if the call is a voice call, a call loss is notified to the transmitting station that generated the call. If the call is a data call, the call is notified to the transmitting station that generated the call. When a command to place a data call in a standby state is sent, and a call for a new connection request occurs when all communication channels are in use and there is a communication channel in use for data communication, the call is a voice call. For example, a command is issued to a transmitting station and a receiving station that are performing data communication on one of the communication channels used for the data communication to stop the data communication and put the data call in a standby state. And allocating the communication channel to the generated voice call and allocating an empty communication channel to the standby data call when the communication channel becomes idle. In the buffer memory, when receiving a command to put the data call in a waiting state, if the transmission station of the data call,
The transmitted data is stored so that untransmitted data is identifiable, and if the receiving station of the data call is the receiving station, the data received so far is stored, and the received data call connection request is set to the standby state. When a communication channel is assigned to
Using the data stored in the buffer memory,
The communication of data subsequent to the data transmitted up to the time when the standby state is established is resumed. Still further, another communication device of the present invention is a communication device used in a communication system in which a plurality of communication stations use a common communication channel, and stores data in communication corresponding to a transmission / reception means and a data call. A buffer memory, and when a connection request for a data call is made or data communication is being performed, when receiving an instruction to place the data call in a waiting state, the buffer memory stores If it is the transmitting station of the data call, the transmitted data is stored so that the untransmitted data is identifiable. If its own station is the receiving station of the data call, the received data up to that point is stored and the When a communication channel is allocated to the connection request of the data call set to the time state, the data stored in the buffer memory is used to transfer data communicated by the time set to the standby state. It is what is adapted to resume the communication of the data to be continued.

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Claims (4)

[Claims] 1. A method of allocating communication channels in a communication system in which a plurality of communication stations use a common communication channel, the method comprising: when a call for a new connection request occurs while all communication channels are in use. When there is a call having a lower priority than the call of the new connection request among the calls performing communication in all communication channels, any one of the calls having the lower priority is used. Stop the communication, assign the communication channel used by the call to the call for the new connection request, and stop the communication if there is a call that has stopped the communication when a vacant channel occurs. A communication channel allocating method for allocating the vacant channel to one of the calls and restarting communication of the call. 2. The communication channel allocating method according to claim 1, wherein the priority of voice communication is higher than that of data communication, facsimile communication, image communication or voice mail communication. 3. The communication channel allocating method according to claim 1, wherein when the communication is stopped, the communication contents up to that time are not discarded. 4. A communication channel allocating apparatus in a communication system in which a plurality of communication stations use a common communication channel, wherein when a new connection request call is generated when all communication channels are in use, When there is a call having a lower priority than the call of the new connection request among the calls performing communication in all communication channels, any one of the calls having the lower priority is used. Means for halting the communication and allocating the communication channel used by the call to the call for the new connection request; and Means for allocating the empty channel to one of the stopped calls and restarting the communication of the call.