JP3112006B2 - Data transfer control method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data transfer control method for transferring data between a terminal and a base station via a radio line, and a device therefor.

[0002]

2. Description of the Related Art Conventionally, in the technology for wirelessly transferring data such as ATM cells, there is a problem that, in addition to a failure of a device, a propagation state is deteriorated due to fading due to weather phenomena such as rain and snow.

Therefore, there is a method of coping with the deterioration of the propagation state in the wireless circuit section, for example, by monitoring the propagation state in the wireless circuit section and a cell loss control method. As a method of monitoring the propagation state in a wireless channel section, for example, Japanese Patent Laid-Open No. 8-274
A configuration described in Japanese Patent No. 727 is known. In the method of monitoring the propagation state in a wireless link section described in Japanese Patent Application Laid-Open No. 8-274727, a loopback is performed by an antenna or a transceiver, and a bit error rate (BE) of data at the time of reception is obtained.
R: Bit Error Rate (R), which detects a device failure by monitoring the deterioration of the propagation state.

On the other hand, in a cell loss control process in a radio transmission section, an FEC (Forward Error Co.) which restores an original signal by adding an error correction function to a random error due to reception level deterioration or the like.
transmission / reception SD for short-time discrete burst errors due to processing, multipath fading, etc.
(Space Diversity), FEC, ARQ
(Automatic Repeat Request)
Processing and the like are known.

[0005] In the ARQ process, a transmitting side attaches a sequence number to an ATM cell and transmits the ATM cell as data for user communication. The receiving side monitors a sequence number of the received ATM cell. Missing ATM
This is a control method of notifying a sequence number of a cell to a transmitting side and retransmitting an ATM cell corresponding to the sequence number notified by the transmitting side.

The ARQ control method includes SSCS (Serv
ice Specialization Convergence
Sublayer) based on retransmission control, for example, I
Q. of TU-TS. For example, a method of implementing a protocol such as the SAAL protocol, or a method such as TCP7OSI /
A method of mounting a null such as TP4 is known.

[0007] For continuous burst errors in a specific slot due to inter-zone interference or the like, there are time slot hopping and frequency hopping.

Further, as a cell loss control process in an ATM backbone network that configures a wired line side from a base station, AAL (ATM Adaptation)
As a retransmission control method in Layer, for example, AA
In L type 5, AAL's CPCS (Common Part C
onvergence Sublayer) There is a method to implement a protocol that guarantees reliability in a layer higher than the layer.

Further, from the viewpoint of charging an ATM cell as data to be transferred, the conventional technology is disclosed in
There is a technique disclosed in Japanese Patent Application Publication No. 9-238133,
The accounting process is calculated based on the number of passing cells of the ATM cell. However, in this conventional method, unnecessary traffic that has become meaningless as data due to deterioration or the like from another network such as a wireless transmission section in the ATM backbone network is charged as it is as the number of passing cells.

[0010] In addition, the billing method of a system that performs wireless transmission often employs time billing instead of metered billing.
Charges are made regardless of the quality of the wireless transmission section. On the other hand, a system in which unnecessary traffic from other networks such as a wireless transmission section is not charged has been proposed in JP-A-09-352202, but the quality state of the wireless transmission section in a system for performing wireless transmission is proposed. Does not make any mention of the accounting control by.

[0011]

As described above, various measures have been taken to cope with the deterioration of the propagation state by monitoring the propagation state in the radio channel section and controlling cell loss, etc. Is extremely deteriorated, there may be a situation where ARQ control in a radio channel section cannot cope with the situation.

Even if the ARQ control is performed in such a situation, the sequence number for retransmission is not normally notified to the other party or is not notified for a long time. Cell transmission efficiency is significantly reduced.

[0013] As described above, continually capturing a channel for which data cannot be normally transferred occupies a radio band unnecessarily, and a new user who wants a new connection or has already communicated. There is a problem that it hinders the bandwidth extension request of a certain user.

According to the present invention, in order to prevent the above-mentioned state in advance, the quality of the received data is periodically monitored and the transmission / reception time of the loop-back data is monitored. It is an object of the present invention to provide a data transfer control method and apparatus capable of releasing a connection for a connection using a line section, improving response to a new call setting request and improving stability of data transfer to another connection. I do.

The second problem is that a wired transmission section (ATM backbone network) is provided in the network.
And a radio transmission section (a radio section between a mobile terminal and a base station), a state occurs in which the propagation state of the radio transmission section is deteriorated and the line quality cannot be guaranteed by retransmission control. If a cell in the middle of data being transferred by AAL5 is discarded and retransmission cannot be performed in time for reading from the reception buffer, the CPCS that has become meaningless because the cell in the middle has been lost.
−PDU (Common Part Convergence Sublayer Protoco
l Unnecessary traffic belonging to the Data Unit)
It will continue to be sent to the M backbone network.

The processing for such unnecessary traffic is not only meaningless, but also delays the transfer of valid data by the amount of unnecessary data. In addition, the power of devices constituting the ATM backbone network is also used for processing unnecessary data, and in the conventional method, the billing value is calculated based on the number of cells passing through the ATM backbone network. There is a problem of being charged.

According to the present invention, when a cell loss that cannot be guaranteed by the ARQ control as described above occurs, cells received after the cell in which the loss is detected by processing in the ATM layer are discarded and the ATM backbone network of the subsequent stage is discarded. In addition to preventing unnecessary traffic from being mixed in, the cell information that should not be charged to the specific user who is using the connection with deteriorated transmission quality before the transmission of user communication data is stopped is transmitted to the subsequent ATM backbone. The present invention provides a data transfer control method and apparatus capable of performing an appropriate accounting process by notifying an ATM exchange within the same, and making the ATM exchange not charge for the notified number of cells. I do.

[0018]

SUMMARY OF THE INVENTION A data transfer control method and apparatus according to the present invention include an ATM terminal group for transmitting and receiving ATM cells, a radio base station for communicating with the terminal group by TDMA, and an ATM.
It consists of an ATM backbone network including exchanges, and a group of ATM terminals connected to the ATM backbone,
The base station reads out the ATM cells from the TDMA frame data received from the ATM terminal, sends out the ATM cells to the ATM backbone network, and performs retransmission control on the ATM terminals when detecting the loss of cells.

Further, based on the result of detection of the data transfer state, the connection using the line section of poor quality is released to respond to a new call setting request and to perform data transfer of the already set call. An object of the present invention is to provide a data transfer control device capable of improving stability.

A base station having a data transfer control function according to the present invention includes a radio quality measuring section for measuring the quality of TDMA frame data received via a radio channel section, and an ARQ control for resending data loss in the radio section by retransmission. And a timer processing unit that performs timer processing based on the radio quality measurement result. The radio quality measurement unit of the base station transmits the BDMA control data of the TDMA frame data.
Measure ER value or send loopback control data to ATM
The communication quality of the wireless channel is measured by transmitting to the terminal and monitoring whether it returns within a predetermined time. Further, after a predetermined time has elapsed, when it is determined that the line state is degraded, there is a means for stopping data transfer and releasing the connection information to the ATM exchange.

Further, when a cell loss that cannot be guaranteed by ARQ occurs, cells subsequent to the cell detected by the processing in the ATM layer are discarded to prevent unnecessary traffic from being mixed into the subsequent ATM backbone network. The number of non-discarded cells of an invalid PDU which is cell data of a PDU having an SN value prior to the detected SN value is measured, and the subsequent ATM
There is means for notifying the exchange as the number of non-charging cells.

Further, the data transfer control method and apparatus according to the present invention provide an ATM for communicating with a base station across the above wireless section.
The terminal may have a configuration in which a wireless channel quality measuring unit and a timer processing unit are added.

The data transfer control method according to the present invention is characterized in that, when data is transferred between a terminal and a base station via a radio channel section, the quality of the transferred data is reduced and the data loss occurs. If the quality of the data does not improve even after a predetermined time elapses after the data is transferred, the data transfer is stopped.

Furthermore, the connection is released by initializing the connection information for the terminal to which the transfer has been stopped without improving the quality of the transferred data.

Further, control data is transmitted from the base station to the terminal, and a state in which the control data does not return from the terminal even after a predetermined time has elapsed is determined as a state in which the quality of the transferred data is not improved. Things.

Further, the control data is transmitted from the base station to the terminal, and the bit error rate of the control data returned from the terminal is measured. The state that continues for a long time is determined as a state in which the quality of the transferred data is not improved.

Furthermore, the data transfer control device of the present invention
A terminal, a base station that transfers data via a wireless link section with the terminal, a data transfer control unit that retransmits the data when the data loss occurs in the wireless link section, Time measuring means for measuring time, and measuring the quality of data transferred in the wireless link section, and when the quality of the measured data is not improved even after a predetermined time measured by the time measuring means, the data is measured. And a wireless quality measuring unit for stopping the transfer of the data.

Further, the data transfer control device of the present invention
The data transfer control unit releases connection by initializing connection information for the terminal whose transfer has been stopped by measuring that the quality of data is not improved even after a predetermined time elapses by the wireless quality measurement unit. is there.

Further, in the data transfer control device of the present invention , the radio quality measurement unit transmits control data from the base station to the terminal, and the control data does not return from the terminal even after a lapse of a predetermined time. Is determined as a state in which the quality of the transferred data is not improved.

Further, in the data transfer control device of the present invention , the radio quality measuring unit transmits control data from the base station to the terminal, and measures a bit error rate of the control data returned from the terminal, The state in which the bit error rate deteriorates below a preset threshold for a predetermined period of time is determined as the state in which the quality of the transferred data is not improved.

Further, in the data transfer control device according to the present invention, before stopping transmission of user communication data to the ATM backbone network, a charge counting process for a connection having a deteriorated transmission quality is performed.
It comprises a TM cell charging and counting control unit, and an OAM processing unit that generates an OAM cell carrying the counted non-charging cell information and sends it to the subsequent ATM exchange.

Further, in the data transfer control device of the present invention,
In the data transfer control device according to claim 5 or 6 , the ATM charging counting control unit uses the identifier of the connection in which the cell loss has occurred, the number of lost cells, and the number of retransmission controls and the number of retransmission cells as non-charging cell information. It is to be calculated.

Furthermore, the data transfer control device of the present invention
The ATM switch according to claim 5 or 6 , wherein the ATM transfer device measures the number of non-charging cells from the OAM cell carrying the non-charging cell information received from the base station, and passes through the connection. It has a call processor for subtracting the cells to be charged from the number of cells.

[0034]

Next, the configuration of a data transfer control device according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a data transfer control device according to the first embodiment of the present invention. The ATM terminal shown in FIG. 1 stores an ATM cell to be transmitted to the base station in a TDMA frame 8.
00 and transmitted to the wireless link section 900. The TD
The base station 300 that has received the MA frame extracts the ATM cell 810 as user data from the TDMA frame, transmits the ATM cell to the subsequent ATM network, and
It communicates with ATM terminals C and D included in the TM network. Here, the gist of the first embodiment of the present invention is that the propagation state deteriorates due to fading or the like in the radio channel section 900, and the ARQ control cannot be performed even if the sequence number is not normally notified. This is to detect the deterioration of the line quality quickly and forcibly release the deteriorated connection.

The outline of the data transfer control method and device of the present invention will be described below.

In the configuration of the ATM terminal (terminal A 100 and terminal B 200), the base station 300, and the ATM network 400, when a call setting request is issued from the ATM terminal, the base station 300
Sends a connection setting request to the ATM switch 410, and connection information such as the VPI value, VCI value, and QoS information of the ATM cell is stored in the buffer area of each of the base station 300 and the ATM terminal.

The ATM terminal assigns a sequence number to each ATM cell, places a cell having a specific ATM identifier on a corresponding time slot, and transmits a radio section as a TDMA frame.

TDMA (Time Division M)
A multiple access (time-division multiple access) communication system is a multi-access system in which signals are transmitted from a plurality of users to a single relay station at the same carrier frequency so that signals do not overlap in time, and communication is performed with each other. Then, the radio frequency is time-divided, a specific time slot in a frame is allocated to a communication party, and communication with the partner station is performed in the allocated time slot. When performing ATM transmission over a wireless line using multi-access technology such as TDMA, the time slot and the VPI or VCI
Is stored in a memory or the like when setting up a new call, and when transmitting an ATM cell having the identifier,
A wireless section can be transmitted as a TDMA frame by placing an ATM cell in a corresponding time slot.

At the base station 300 that has received the frame, the ATM cell is read from the TDMA time slot, and at the same time, it is monitored from the sequence number assigned to the cell whether there is any cell loss. When detecting the loss of the ATM cell, the control reads the sequence number of the lost cell and the control data corresponding to the connection, and requests the source ATM terminal to retransmit the cell corresponding to the lost sequence number. I do. When performing such retransmission control, there is a case where a sequence number for retransmission is not notified due to deterioration of a wireless section. In the present invention, in such a case, in order to prevent a state in which a deteriorated connection is continuously captured for a long time, a quality monitoring unit for two wireless communication sections using the following timer is provided. That is, means for transmitting loopback data from the base station 300 to the ATM terminal, monitoring whether the control data returns from the ATM terminal within a predetermined time using the loopback response monitoring timer tr, and transmitting the wireless section. This is means for monitoring the BER, which is the quality deterioration of the data to be performed, and using a continuous monitoring timer ts for detecting a state where the BER value continuously deteriorates from a predetermined threshold value at a constant period.

The BER is a value obtained by averaging the number of bit errors in a bit unit for a long time to represent the bit error characteristics of digital transmission and indicating the ratio to the total number of bits. As a result, there is a point that the quality cannot be accurately expressed in a data signal which is greatly affected by a short-time code error phenomenon such as a burst code error. That is, even if the code error rate is considerably deteriorated in a very short time, there is a case where it is not reflected on the BER.

Therefore, according to the present invention, when the loss of ATM cells is detected, the BER value is compared with a certain threshold value, and the loopback control data is transmitted in addition to the measuring means for measuring the quality deterioration of data transmission. Accordingly, it is possible to detect deterioration occurring in a short time and quickly detect an abnormality in the propagation state.

Also, in the quality measurement using the BER of the present invention, the BE
Start counting up of the continuous monitoring timer for R measurement, and as a result of BER measurement on received data,
If the state deteriorated from the preset threshold value continues for a certain period of time, data transmission to the connection is stopped, and in the method using loopback, if the control data does not return within a predetermined time, the connection of the connection is Stop data communication.

The quality monitoring processing will be described below.

When the base station 300 detects a missing cell, it turns on the loopback flag of the control data and turns on the ATM.
The control data is multiplexed to the control channel of the TDMA frame and transmitted to the terminal, and the timer processing unit 390 is requested to start the response monitoring timer for monitoring the loopback flag. At the same time, the communication quality of the wireless line is measured by BER measurement. As a result of the quality measurement, if the deterioration exceeding the BER threshold continues for a certain period of time (ts> = U), or if the control data for loopback does not return from the ATM terminal, the deterioration of the quality must be improved. Upon making a determination, the base station 300 stops data transmission and reception of the connection and releases the connection.

As a specific procedure for stopping data at this time, the base station transmits control data in which the data transmission stop flag is set to ON to the ATM terminal. Also, A
A request to release the connection is made to the TM exchange 410.

When the data transmission stop flag ON in the control data received from the base station 300 is detected in the reception buffer of the data transfer control unit 110 of the ATM terminal, the data transmission of the connection to the base station 300 is stopped. .

The ATM exchange 410 receives the connection release request from the base station 300 and receives the UNI release.
Based on signaling processing such as 4.0, the base station 30
0, request to release connection between ATM terminals. FIG. 8 shows the timing of timing of the continuous monitoring timer ts.
This will be described with reference to FIG. FIG. 8 is a conceptual diagram for explaining the timing of the continuation monitoring timer of the present invention.

In FIG. 8, after the BER measurement starts, B
When the ER measurement value exceeds a predetermined threshold value S at time t1, the continuation monitoring timer ts starts measuring time.

While the result of the BER measurement is deteriorating by a certain value or more, the continuous monitoring timer ts keeps counting up. However, if the BER value falls below S at time t2, the continuous monitoring timer ts stops counting up. And clear the counter value. Further, when the continuously measured BER value deteriorates by the threshold S or more at the time t3, the continuous monitoring timer ts starts counting up again. It is determined that the quality of the connection is significantly deteriorated, and the operation of releasing the connection is started.

Next, the first embodiment will be described in detail with reference to the drawings.

As described above, in FIG.
0 and the terminal B 200 transmit and receive data to and from the base station 300 in a TDMA frame via the radio channel section 900.

Base station 300 receives the TDM received from terminal A 100 and terminal B 200 via radio link section 900.
A radio quality measurement unit 380 for measuring the quality of the A frame data 800, and a data transfer control unit 3 for performing ARQ control for rescuing data loss in the radio channel section 900 by retransmission.
10 and a timer processing unit 390 that performs a timer process based on the wireless quality measurement result. The timer processing unit 390 includes a continuation monitoring timer ts for measuring the continuation of the BER quality degradation state already described, and a response monitoring timer tr for measuring whether the loopback data returns within a predetermined time. Each can be set.

Further, the data transfer control unit 310
As shown in the figure, the TDMA frame 800 transmitted from the ATM terminal via the radio section is stored, and the ATM cell 810 is stored.
And a transmission buffer 33 for loading the ATM cells 810 received from the ATM backbone into a TDMA frame 800 to be transmitted to the ATM terminal.
0, and further includes a retransmission processing unit 340 that transmits and receives data between the reception buffer 320 and the transmission buffer 330 and has a retransmission control function.

An ATM backbone network 400 having an ATM switch 410 connected via an optical cable 910 is connected to the base station 300.

Further, the ATM terminal C5 is connected to the ATM backbone network 400 via the optical cable 910.
00 and an ATM terminal D600 are connected.

Here, the ATM cell retransmission method will be described. ATM terminal on transmission side (for example, terminal A100)
Then, the ATM cell to which the sequence number of the ATM cell is added is transmitted, and the cell is written in a retransmission memory (not shown) in preparation for retransmission. The received base station 3
At 00, the sequence number of the ATM cell is monitored, cell loss is detected due to the lack of continuity, and when the cell loss is detected, the retransmission processing unit 340 determines the sequence number of the missing cell with the control data. Notify the sending ATM terminal. The ATM terminal extracts, from the retransmission memory, an ATM cell having the sequence number of which notification has not been received, and retransmits the ATM cell to the base station 300. Note that the retransmission memory may be provided in the transmission buffer or in the retransmission processing unit.

Next, the configuration of the TDMA frame 800 used in the radio link section will be described.

The TDMA frame is, as shown in FIG.
Consisting of a plurality of access data 201 for antenna control, a plurality of control data 202 used for controlling data transfer between the base station 300 and the terminal A 100 and the terminal B 200, and a plurality of user channels 203 for communication between users. Have been.

The control data 202 includes, for example, a loopback flag, ARQ control information, link information, alarm information, and the like. Further, in the user communication data 203, n ATM cells are multiplexed.

FIGS. 4 to 6 are flowcharts showing operations in base station 300 according to the embodiment of the present invention. The operation of the embodiment of the present invention will be described with reference to FIGS.

The base station 300 stores the TDMA frame data 800 received from the terminal A 100 in the reception buffer memory 322 by the reception buffer write control unit 321. Then, the T stored in the reception buffer memory 322
The DMA frame data 800 is read by the reception buffer read control unit 323 in ATM cell units, and
The cell 810 is transmitted to the ATM backbone network 400.

If the ATM cell 810 to be ARQ controlled contained in the user communication data 203 received from the terminal A 100 is damaged, that is, there is a cell loss, the retransmission processing unit 340 executes retransmission control.

The radio quality measuring section 380 of the base station 300
The communication quality of the wireless line is measured by measuring the BER value of the control data 202 corresponding to each of the terminals A100 and B200, that is, the BER value which is the bit error rate of the data at the time of reception. Note that the measurement of the BER itself is a category of the measurement according to the related art.

As the state of the radio link deteriorates, the error rate increases, and it is monitored whether or not the measured value does not deteriorate beyond a threshold of a BER value indicating a certain line quality. If not, just monitor and wait for the measurement result of the next cycle.

If the BER measurement result indicates a deteriorated state exceeding the threshold, the continuation monitoring timer ts starts counting up to monitor the continuity of the deteriorated state.

BE during the counting of the continuous monitoring timer ts
If the wireless quality line is improved to such an extent that the R measurement value does not exceed the threshold value (S), the count-up of the continuous monitoring timer ts is stopped and cleared, and again, if the deterioration state indicating the threshold value is exceeded is indicated again. , Start counting up.

According to the above processing, even in the case where the quality is deteriorated such that the sequence number is not notified in the ARQ control, the deterioration of the propagation state can be quickly detected. Thus, a connection that cannot provide a normal communication service to the user can be released, so that even when a new call connection request is generated, the request is not made to wait.

BE indicating line quality deterioration equal to or higher than a certain threshold
When the R measurement value is obtained continuously for a predetermined time, the process proceeds to a connection termination process shown in FIG.

The detailed operation will be described with reference to FIG. FIG.
5 is a flowchart showing a quality measurement operation using BER.

The reception buffer 320 performs the operation of receiving data from the ATM terminal, and when the loss of the received cell is detected due to the loss of the sequence number (step 1), the wireless quality measuring unit 380 measures the BER of the received data. Is started (step 2).

At the same time, since BER measurement is performed for T1 time,
The elapsed time from the ER measurement is observed (step 3).

The BE measured for the received data
A comparison is made as to whether the R value has deteriorated below a predetermined threshold value S (step 4).

If the measured BER value has not deteriorated below the threshold value (step 4: No), the continuous monitoring timer ts has not yet started measuring time (step 8: No), and the BER measurement is continuously performed on the received data. Do (Step 2
What).

If the BER value has deteriorated below a predetermined threshold value (step 4: Yes), the continuation monitoring timer ts has not started measuring time in the initial state when the radio quality measurement has started (step 5: No). Then, the counting of the continuous monitoring timer ts is started (step 6), and the measurement of the BER is continued (to step 2).

After the continuation monitoring timer starts counting, the value of the BER measured for the newly received data (step 2) is compared with a predetermined threshold value until the time T1 elapses after the start of the BER measurement (step 3) (step 3). 4) If it has deteriorated below a predetermined threshold (Step 4: Yes),
The BER deterioration continuous monitoring timer is already counting (step 5: Yes), and it is determined whether the continuation monitoring timer starts counting and has continued for a predetermined time U (step 7).
If the continuation monitoring timer ts has not started for the predetermined time U after the start, the operation of comparing the BER value measured for newly received data with the threshold value S is repeated (steps 2 to 4). When the measured BER value is improved more than the predetermined threshold value S (Step 4: No), the continuation monitoring timer ts which has already been started is reset (Step 9), and the wireless quality measurement ends.

When the deterioration of the BER value equal to or more than the threshold value has continued for a certain time U or more (step 9: Yes), the data transmission section is determined to be unsuitable for data transmission, and the corresponding connection shown in FIG. 6 is released. Start processing. (processing
A) As described above, the wireless quality measuring unit 380 monitors the quality of the wireless channel by measuring the BER, and determines the quality of the wireless channel such that it is determined that the normality of data transfer cannot be guaranteed even by ARQ control. The continuation of the deterioration state is identified.
The loopback monitoring as the second monitoring means will be described with reference to FIG.

The loopback monitoring means transmits control data with a loopback flag from the base station 300 to the ATM terminal at regular intervals, and the response data is returned from the ATM terminal by the loopback monitoring timer. Monitor the time to come.

Since a predetermined time for determining that the line quality has deteriorated to a state where data transfer cannot be guaranteed by ARQ control is set in this loopback monitoring timer, response data from the ATM terminal is not transmitted. If it does not return by the end of the timing, it is determined that the line quality is extremely deteriorated.

Similarly, the quality monitoring means using loopback will be described with reference to FIG. In the ARQ control, when a lack of SN is detected (step 11), a loopback flag of control data is turned ON in a transmission buffer to be transmitted to the ATM terminal 100 (step 12).
Send to TM terminal. Then, in order to monitor whether the loop-back control data returns to the predetermined time, the timer of the response monitoring timer tr is started (step 13).

The reception buffer 320 of the base station monitors the reception of the loopback response data (step 14).
Until a predetermined time has elapsed, it is monitored whether loop-back response data is received (step 15: No). When the loopback response data is not received after a predetermined time has elapsed (step 15: Yes), the corresponding connection release process shown in FIG. 4 is started (process B).

If the loopback response data is received within a predetermined time (step 14: Yes), the data transmission section is determined to be normal, the response monitoring timer tr is reset (step 15), and the radio quality measurement is performed. finish.

Next, the release of the data transmission section in which the deterioration has been detected by the above processing A and B and the initialization processing will be described with reference to FIG.

When processing A and B determine that the data transmission section has deteriorated, the ATM corresponding to the control data for which the deterioration has been detected is used.
Is retrieved from the reception buffer (step 20). Also, a retransmission processing unit 340 that performs ARQ control
, The retransmission process is stopped (step 21). Further, the reception buffer 320 and the transmission buffer 33 of the base station
At 0, data transmission to the subsequent ATM backbone is stopped (step 22), and data transmission to the ATM terminal 100 is stopped (steps 22 and 23). Further, since the connection stored in the reception buffer 320 and the transmission buffer 330 becomes unnecessary, the storage area storing the corresponding information is initialized. (Step 24). Also, the ATM switch 410 at the subsequent stage from the base station.
, A connection release request is transmitted (step 25). As a result, the ATM exchange releases the connection by signaling. When a request for setting a new connection is issued, the base station 300 performs a setting operation for a new connection in accordance with a call setting request from the ATM switch 410, and stores information on the newly set connection in each buffer area. (Step 2
6).

The operation of the base station regarding quality monitoring and connection release has been described above.

Next, the operation of the ATM terminal will be described mainly with reference to FIG.

FIG. 7 is a flowchart showing the operation of the ATM terminal according to the first embodiment of the present invention.

Hereinafter, the quality measurement operation on the terminal side will be described.
In the loopback of control data, the same time slot is not always used in the uplink and downlink radio sections in the TDMA frame propagating in the radio section. For this reason, the loopback control data is
The data is transmitted to the TM terminal, and the ATM terminal carries control data in a corresponding time slot, and returns to the base station.

The ATM terminal 100 performs a process of receiving user data from the base station 300.
It is monitored whether or not the loopback flag in the control data 202 received from 00 is ON (step 31).

If the loopback flag is not ON, a normal data receiving operation is performed (step 31;
No), when the loopback flag ON is detected in the control data transmitted to the ATM terminal by the quality measurement processing of the base station 300 (Step 31; Yes), the control data is looped back.

Here, there are cases where different time slots are used in the TDMA frame for the same ATM connection in the upstream and downstream, and the received control data is loaded in the corresponding time slot in the upstream (base station side) direction. For transmission, the reception buffer 320 of the data transfer control unit 110 of the ATM terminal refers to the connection information in the control data 202 and reads the corresponding information (step 32).

Next, the transmission buffer read control unit 333 is sent to the control data 20 corresponding to the connection information.
The transmission buffer read control unit 333 requests the base station 300 to turn on the loopback flag in the control data 202 (step 34), and requests the base station 300 to turn on the loopback flag in step 2 (step 33). Send.

As described above, the base station 300 monitors whether the loopback control data returned from the ATM terminal returns within a predetermined time, and the control data does not return within the predetermined time. In this case, the data stop of the connection is notified to the ATM terminal.

On the other hand, in the ATM terminal 100, the base station 3
It is monitored whether or not the data transmission stop flag of the control data 202 received from 00 is ON (step 35). If it is determined that the data transmission stop flag is not ON, the wireless quality measurement is ended.

When the ON is detected, the data transmission of the ATM connection to the base station is stopped. As a specific operation, the reception buffer 320 of the data transfer control unit 110 transmits the user communication data 2 corresponding to the connection information to the transmission buffer read control unit 333.
03 (step 36), and the transmission buffer read control unit 333 receives the request to stop transmission of the base station 300.
, The transmission of the user communication data 203 is stopped (step 37).

Thus, the terminal A100 and the terminal B2
For a user who uses 00, communication quality degradation in a wireless section occurs due to fading or the like due to rain, and a new call waiting state due to occupation of a wireless band caused by stagnation of retransmission control can be eliminated. Further, the influence on other users due to the occupation of the wireless band can be eliminated.

In addition, since unnecessary connections in a quality degraded state are positively released, processing relating to unnecessary connections is suppressed, and efficient operation of resources of the entire network can be achieved.

Next, a second embodiment of the present invention will be described with reference to FIG.

In the second embodiment, an ATM terminal (A10
0 and B200) with the addition of the wireless channel quality measuring unit 380 and the timer processing unit 390 of the base station 300 of the above-described first embodiment.

[0099] Accordingly, when the ATM terminal detects the loss of the downstream ATM cell from the base station 300 to the ATM terminal 100 side, or when a retransmission request is received from the base station, the ATM terminal Can perform the same quality measurement operation as the base station 300 described in the first embodiment. As a result, when the ATM terminal detects the deterioration of the data transmission quality in the wireless section, a trigger to release the connection can be given from the ATM terminal. Therefore, it is possible to speed up the detection of the quality deterioration and to improve the accuracy of the detection. Further, by adopting a configuration in which the BER on the upstream or downstream side of the line is measured by each of the base station 300 and the ATM terminal, the fault section can be isolated. This has the effect of making it easier.

ATM terminal 10 in the second embodiment
The data transfer control unit 110 of 0 has the same configuration as the data transfer control unit 310 of the base station 300.

Hereinafter, the data transfer control unit 110 of the present invention will be described.
The operation of the ATM terminal 100 provided with the timer processing unit 111 and the radio quality measurement unit 112 will be described. The basic operation is the first embodiment in which the function is provided in the base station and the flow of the processing operation. Is the same.

Radio quality measuring section 112 of ATM terminal 100
Is B in the control data 202 received from the base station 300.
It measures the communication quality of the wireless line, such as measuring the ER value, and requests the timer processing unit 111 to start counting up the timer.

Then, as a result of the measurement, if the state where the BER value exceeds the threshold value continues for a certain period of time after starting the count up, or the loopback flag of the control data is turned on, and the timer starts counting up. hand,
After transmitting the control data 202 from the terminal A 100 to the base station 300, if the control data 202 does not return even after a predetermined time has elapsed, it is determined that quality degradation has occurred and the base station 300 The data transmission is stopped, and a request to release the ATM connection is transmitted to the base station 300.

For the ATM connection, data transmission can be stopped first on the user side, so that the processing load on the base station and the ATM switch can be reduced.

As described above, in the second embodiment, more stable data transfer can be performed.

In the first and second embodiments, the ATM
Due to the transmission quality deterioration of the radio link section between the terminal and the base station, when detecting the quality deterioration such that it is determined that the cell quality cannot be guaranteed even in the ATM cell-based retransmission,
The method of stopping the transmission of the data and releasing the connection has been described.

However, also in the above-described embodiment, it is inevitable that unnecessary traffic is mixed in the backbone at the subsequent stage.

That is, for a group of data (PDUs) that have become meaningless and become unnecessary due to the partial loss of the ATM cells, the cells after the lost cells are discarded by the base station. A PDU that has been received and transmitted to a subsequent ATM exchange has a problem that, despite being invalid as data, the latter ATM exchange is charged as a passing cell as it is. .

In the third embodiment, the purpose of solving this problem is to perform appropriate accounting in the subsequent ATM switch, so that the deterioration of transmission quality and the connection release described in the first embodiment are detected. In addition to the procedure, the number of cells belonging to the invalid PDU that could not be discarded is calculated, notified to the subsequent ATM exchange, and the notified ATM exchange counts the corresponding connection as the number of charging cells. Subtract the non-billing amount from the number of passing cells
This is to calculate a pay-as-you-go value.

Specifically, a start message (BO) indicating that the ATM cell at the ATM terminal is the head of the frame with respect to the head cell of the AAL CPCS-PDU.
M) An identifier is added, a sequence number (SN) value is added, the ATM cell with the additional information is transmitted to the radio base station as a TDMA frame, and the received radio base station receives the ATM cell before the lost cell. There is means for determining the number of cells in the first half included in the PDU as the number of non-charging cells.

Then, an OAM cell containing a count value of the number of cells to be discarded, which is no longer needed due to partial cell loss but has already been transmitted to the ATM backbone, is generated. Subsequent ATM
By notifying the exchange, an appropriate charging process is to be performed.

Here, the concept of the PDU will be described with reference to the drawings.

FIG. 16 is a conceptual diagram for explaining the AAL and PDU outline of the ATM cell.

The AAL has a function of decomposing user information into ATM cells and assembling the original user information from the cells. The function of the AAL is further improved as shown in FIG.
R (Segmentation Reassembly Layer) and CS (Conve
rgence Sublayer), and CS is further divided into CPCS
(Common Part Convergence Sublayer) and SSCS (Se
rvece Specific Convergence Sublayer).

The CPCS function includes, for example, error detection,
Includes padding function, packet length display function, SAR
The layer divides the CPCS-PDU into ATM cells, and adds a sequence number or the like as needed.
That is, the data portions of a plurality of ATM cells are treated as a PDU of the AAL, and when the ATM cells included in this PDU are partially missing, the PDUs become all invalid data. I will.

The AAL is classified into five types AAL1 to AAL5 according to the upper layer to which the AAL is applied, although not described in detail. For example, in the AAL3 / 4, the order of the ATM cells constituting the PDU is determined by the sequence number, the CPCS -BOM and EOM identifiers indicating the first and last cells of the message of the PDU are assigned to each cell and decomposed into cells. On the other hand, in the type with simplified functions like AAL5, BOM
Decomposes from PDU into each ATM cell without adding / EOM identifier and performs data transmission.

In the type such as AAL5, when a cell is lost, means for discriminating the number of cells included in the first half of the cells included in the CPCS-PDU that cannot be discarded even if the cells after the lost cell can be discarded. There is no.

In the present invention, the ATM terminal transmits the CPCS to the cell.
BO indicating the first cell of the PDU message
M identifier and the sequence number of the cell are assigned and transmitted.
At the receiving base station, the sequence number of the cell and the BO
By providing a function of detecting an M (Begin of Message) identifier and counting the number of passing cells received later from the BOM identifier-assigned cell, a function of calculating the number of non-charging cells is provided.

The configuration of the third embodiment will be described below.

In the third embodiment, the base station, the ATM exchange, and the ATM terminal shown in the first embodiment are provided with a function for performing appropriate accounting processing.

FIG. 12 is a block diagram showing an ATM terminal according to the third embodiment of the present invention.

The ATM terminal has a transmission buffer 550 for performing data communication with the base station, a reception buffer 560, and a retransmission processing unit 570 as main components. And a BOM identifier / SN assigning unit 554 for assigning a BOM identifier.

The ATM terminal assigns a sequence number (SN) indicating the order of the cells to the cells stored in the transmission buffer by the BOM identifier / SN assigning unit 554, and also sets the first cell of the CPCS-PDU frame. A BOM identifier is assigned to the cell corresponding to. And it transmits to a base station as a TDMA frame.

FIG. 15 shows an ATM added with an identifier of the present invention.
3 shows an example of a cell format. In the present invention, a sequence number (SN) indicating a cell order is included in a header part of an ATM cell to be transmitted, and a start message (BO indicating that this is a head cell of a frame is indicated as a head cell of a CPCS-PDU.
M) identifier.

By the way, since AAL3 / 4 has a function of assigning a SAR type indicating the type of BOM / EOM and a sequence number as an AAL function, it is not necessary to add an extension header. A sequence number and a BOM / EOM identifier supported by AAL3 / 4 may be used, or an extension header adding function may be provided regardless of the AAL type.

FIG. 10 is a block diagram of a data transfer control device of a base station according to a third embodiment of the present invention.

FIG. 10 shows a data transfer control unit 710 of the base station according to the present invention, which comprises a transmission buffer 730, a reception buffer 720, a retransmission processing unit 740, and an OAM cell processing unit 710. The transmission buffer 730 includes a transmission buffer write control unit 731, a transmission buffer memory 73
2, the transmission buffer read control unit 733, the reception buffer 720, the reception buffer write control unit 721,
It comprises a reception buffer memory 722, a reception buffer read control unit 723, an ATM cell accounting count control unit 724, and a BOM identifier / SN removal unit 725.

That is, this configuration is different from the configuration of the base station shown in FIG.
And a BOM identifier / SN removing unit 725, an OAM processing unit 750 for generating, transmitting, and receiving an OAM cell carrying information on the number of non-charging cells.
Is provided.

When the radio base station receives the TDMA frame from the ATM terminal, reads out the ATM cell with the additional information and reads the BOM identifier and sequence number (S
N) Monitor the cell loss using the storage area, perform necessary processing, remove it in the BOM identifier / SN remover, and send it to the ATM backbone.

When the missing cell is detected and the data communication of the connection is determined to be stopped, received data after the missing cell is discarded and the missing cell is included.
The number of cells included in the first half of the PDU is counted.

That is, counting is started from the cell having the BOM identifier, and the number of cells up to the missing cell is calculated. Then, the calculated value is mounted in an OAM cell to be transmitted to the ATM backbone, and a notification is sent to a subsequent ATM switch before the connection is released.

FIG. 11 is a block diagram showing an ATM switch according to the third embodiment of the present invention.

The configuration of FIG. 11 shows an ATM switch 410 according to the present invention, which includes a line interface section 420 for providing an interface with a radio access network, an ATM switch section 430 for switching a cell route based on ATM cell header information, and a call switch. It comprises a call processor 440 for setting, releasing, managing and the like, and a memory 450.

The line interface section 420 includes a physical interface section 421 for performing a physical layer process, and the base station 30.
UPC device 422 for monitoring the flow rate of cells flowing from 0 to the ATM backbone network 400, charging device 423 for measuring the number of passing cells for each call, and the number of non-charging cells from the base station 300, insertion / extraction of OAM cells And AA
The OAM / SAR processing unit 424 performs segmentation / reassembly of L PDUs. The billing device 423 of the ATM exchange 410 normally measures the number of cells passed per call, and the call processor 440 periodically collects billing data from the number of cells passed per call from the billing device 423. And periodically updates the memory storing the billing data. In response to a connection release request from the base station 300, for example, the connection between the ATM terminals that communicate with each other (for example, the ATM terminal A100 and the ATM terminal 600) is released. , The usage-based billing value is calculated.

Next, the operation of the third embodiment will be described with reference to FIG.
This will be described in detail with reference to the flowchart shown in FIG.
Note that the radio quality measurement operation is the same as that of the first embodiment, and thus the description is omitted.

In the ATM terminal shown in FIG. 12, a sequence number (SN) indicating the order of cells is assigned to the cells stored in the transmission buffer memory 552 by a BOM identifier / SN assigning unit 554. A BOM identifier is assigned to a cell corresponding to the first cell of the CPCS-PDU frame. And it transmits to a base station as a TDMA frame.

TDM received by base station receive buffer
The A frame is written into the reception buffer memory 722 by the reception buffer write control unit 721.

The reception buffer read control unit 723 reads the TDMA frame stored in the reception buffer memory 722 in the unit of ATM cell data with the additional information. The read ATM cell data is transmitted to the ATM cell charging control unit 724.

FIG. 14 is a block diagram showing the configuration of the ATM cell charging and counting control unit.

The ATM cell charging counting control section 724 transfers the received cell to the BOM detection processing section and the cell loss detection processing section.

The cell-missing detection processing section 152 has a counter for identifying and counting the SN assigned to each cell, and the SN of each cell read from the reception buffer memory.
Is compared with a value obtained by adding 1 to the current counter value. If they match, it is determined that the reception is normal, and if they do not match, it is determined that the reception is abnormal (cell loss).

If the reception is normal, the cell data with the additional information is transferred to the BOM identifier / SN remover 725. After the BOM identifier / SN remover 725 removes the additional information, the BOM identifier / SN is transmitted to the ATM backbone ATM exchange as a normal ATM cell.

In the case of abnormal reception, the cell loss detection processing unit 1
52 is a sequence number (SN) for the radio quality measurement unit.
Notify of missing. Then, the radio quality measurement unit starts a radio quality measurement operation.

Upon detecting such a cell loss, the cell loss detection section 152 holds the SN value immediately before the SN value of the lost cell and notifies the non-charging cell number calculation section 153. .

Then, a notification is made to the reception buffer, and the reception data after the lost cell is temporarily stored in the buffer.

In the reception buffer, the result of the quality measurement is waited for a predetermined time, and when the quality measurement determines that the data transmission section is degraded (processes A and B shown in the first embodiment), The cells subsequent to the lost cell are discarded.

The non-charging cell number calculation section 153 calculates the non-discarded cell number information of the cells from the BOM cell to the cell loss of the CPCS-PDU for each connection.

Then, the number of cells to be discarded for each connection is notified to the OAM cell processing unit, and the ATM switch is notified of non-charging cell number information.

Next, the operation of the base station as a whole except for the details of the operation of the ATM cell charging counting unit will be described.

In the radio quality measurement operation of the first embodiment, when it is determined that the radio transmission section has deteriorated,
When B determines that the data transmission section has deteriorated, the reception buffer is searched for ATM connection information corresponding to the control data for which the deterioration has been detected (step 50). Also, A
It requests the TM cell charge counting unit 724 to stop the charge count processing for the connection (step 51).

A retransmission processing unit 740 for performing ARQ control
In, the retransmission processing is stopped (step 52).

Next, the TDMA
It notifies the control data number defined on the frame 800, requests the OAM cell processing unit 750 to issue an OAM cell carrying non-charging cell information for the connection, and the OAM cell processing unit 750 The counting information (non-charging cell information) is mounted on the specific OAM cell and transmitted to the ATM backbone network (step 53).

The reception buffer and the transmission buffer of the base station stop transmitting data to the subsequent ATM backbone and stop transmitting data to the ATM terminal 100 (step 54).

Further, since the connection information stored in the reception buffer and the transmission buffer is not required, the storage area storing the corresponding information is initialized (step 55). Further, the base station transmits a connection release request to the subsequent ATM switch (step 56), whereby the ATM switch releases the connection by signaling.

When a request for setting a new connection is issued, the base station performs a setting operation for a new connection in response to a call setting request from the ATM exchange, and transmits information on the newly set connection to the reception buffer / transmission buffer. (Step 4)
7).

On the other hand, terminal A100 performs the same operation as shown in the flowchart of FIG.

On the other hand, ATM switch 410 is connected to base station 30.
In response to the connection setup / release (disconnection) request from the base station 300, the connection setup / release of the base station 300 and the ATM terminal is performed based on a signaling process such as UNI 4.0. The billing device 423 measures the number of passing cells for each call, and the call processor 440 periodically sends billing data of the number of passing cells for each call and the number of cells to be discarded from the billing device 423. And the memory 450 is periodically updated.

As a result of the radio quality measurement from the base station, when a connection release request and an OAM cell carrying the non-charging cell number information are received, a call disconnection process is performed, and a user corresponding to the connection is processed by the charging device. Is calculated.

That is, OAM cell information carrying non-charging cell information received from the base station is received, and OAM / SAR
The processing device 424 analyzes the number of non-charging cells included in the cell and the connection information. Further, the content of the memory 450 for storing the billing data is read out, and the following calculation is performed to calculate the metered billing value.

Usage-based charging value = number of passing cells * s1-number of non-charging cells * s2 Here, the number of passing cells and the number of non-charging cells are data collected from the charging device, and s1 indicates a unit charge per cell. S2 is a constant indicating the amount of money to be subtracted from the call charge for each cell.

After the connection is released, the AT
The M switch 410 performs signaling processing to set up the base station 300 and the ATM in order to set up a new connection.
Performs a new connection setup process for the terminal.

As described above, for the connection in a state where the data quality is not improved, the number of cells discarded due to the stoppage of the lost cell number retransmission process is not charged, so that unnecessary charging count can be suppressed.

Next, a fourth embodiment of the present invention will be described.

[0164] In the fourth embodiment, an ATM terminal (A
100 and B200) to which the data transfer control unit including the ATM cell charging and counting control unit and the OAM cell processing unit described in the third embodiment, a radio channel quality measurement unit, and a timer processing unit are added. is there.

The data transfer control unit of the ATM terminal assigns a BOM identifier and a sequence number to the ATM cell to be transmitted to the base station, transmits the ATM cell as a TDMA frame, and monitors whether or not the cell received from the base station is missing. Do.

In the base station, the AT transmitted in the downlink direction
A BOM identifier and a sequence number are assigned to the M cell, and A
The transmission is performed to the TM terminals (A100 and B200).

When the ATM terminal detects the loss of the ATM cell in the downlink direction on the ATM terminal side from the base station 300, or when a retransmission request is received from the base station, the ATM terminal ATM described in the second embodiment
Performs the same quality measurement operation as the terminal.

When the base station receives the OAM cell carrying the non-charging cell number information received from the ATM terminal and the connection release request, it stops the data transmission and reception of the corresponding connection and initializes the storage area. Together with the connection release request and information on the number of non-charging cells.
Notify the exchange. Then, the ATM exchange releases the connection.

In the fourth embodiment, since quality measurement can be performed for each terminal and the number of non-discarded cells can be counted,
There is an effect that quick deterioration detection and more stable data transfer can be performed.

[0170]

According to the present invention, if the quality of data to be transferred does not improve even after the lapse of a predetermined time, the transfer of data is stopped. Unnecessary occupation of the wireless band can be prevented by holding the wireless line in a state where the quality of the data that cannot be transferred has deteriorated, a new connection can be obtained by a new user, and data is already being transferred. Users can transfer data stably.

Further, by releasing unnecessary connections when data quality does not improve, it is possible to improve the utilization efficiency of resources of the entire network.

Further, the data quality can be easily recognized with a simple configuration by transmitting and receiving the control data within a predetermined time and confirming the reply of the control data within the predetermined time.

When a cell is lost, transmission of cell data after the lost cell is stopped, and data of the number of previously lost cells included in the same block is added to the OAM cell data, and the ATM at the subsequent stage is added. By notifying the backbone network, unnecessary traffic can be prevented from being mixed in, and more accurate billing can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram of a data transfer control device according to a first embodiment of the present invention.

FIG. 2 shows a TDM accessed between a base station and a terminal.
FIG. 3 is an explanatory diagram showing an A frame format.

FIG. 3 is a block diagram showing a data transfer control unit of the base station;

FIG. 4 is a flowchart showing a quality measurement operation using BER.

FIG. 5 is a flowchart showing a quality measurement operation using loopback.

FIG. 6 is a flowchart showing an operation of the base station according to the first embodiment of the present invention.

FIG. 7 is a flowchart showing an operation on the terminal side of the present invention.

FIG. 8 is a conceptual diagram for explaining the timing of counting of a continuous monitoring timer according to the present invention.

FIG. 9 is a block diagram of a terminal of the data transfer control device according to the second embodiment of the present invention.

FIG. 10 is a block diagram of a data transfer control device of a base station according to a third embodiment of the present invention.

FIG. 11 is a block diagram showing an ATM exchange according to the third embodiment;

FIG. 12 is a block diagram of an ATM terminal of the data transfer control device.

FIG. 13 is a flowchart showing an operation of the data transfer control device on the base station side.

FIG. 14 is a block diagram showing a configuration of an ATM cell charging and counting control unit according to the embodiment.

FIG. 15 is an example of an ATM cell with an identifier according to the embodiment;

FIG. 16 is a conceptual diagram illustrating an outline of AAL and PDU of an ATM cell.

[Explanation of symbols]

 Reference Signs List 100 terminal A 110 data transfer control unit of terminal A 111 timer processing unit of terminal A 112 wireless quality measurement unit of terminal A 200 terminal B 300 base station 301 data transfer control unit of base station 320, 560 reception buffer 321, 561 reception buffer Write control unit 322, 562 Receive buffer memory 323, 563 Receive buffer read control unit 330, 550 Transmission buffer 331, 551 Transmission buffer write control unit 332, 552 Transmission buffer memory 333, 553 Transmission buffer read control unit 340, 570 Retransmission processing unit 380 Radio quality measurement unit 390 Timer processing unit 400 ATM backbone network 410 ATM exchange 411 ATM exchange 420 Circuit interface unit 421 Physical interface 422 UPC device 423 Billing Device 424 OAM / SAR processing device 430 ATM switch 440 Call processor 450 Memory 500 Terminal A 600 Terminal C 610 Terminal D 710 Base station data transfer control unit 720 Receive buffer 721 Receive buffer write control unit 722 Receive buffer memory 723 Read receive buffer Control unit 730 Transmission buffer 731 Transmission buffer write control unit 732 Transmission buffer memory 733 Transmission buffer read control unit 740 Retransmission processing unit 800 TDMA frame 810 ATM cell 900 Wireless line section 910 Optical cable

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Satoru Yamano 5-7-1, Minato-ku, Tokyo NEC Corporation (56) References JP-A-2-243033 (JP, A) JP-A-4 JP-A-361469 (JP, A) JP-A-63-193734 (JP, A) JP-A-1-120142 (JP, A) JP-A-1-316040 (JP, A) JP-A-5-292082 (JP, A) JP-A-10-190679 (JP, A) JP-A-61-33035 (JP, A) JP-A-3-198553 (JP, A) JP-A-7-273801 (JP, A) 8802 (JP, A) Japanese Unexamined Patent Publication No. 9-153995 (JP, A) Japanese Unexamined Patent Publication No. 9-252482 (JP, A) Japanese Unexamined Patent Publication No. 11-284635 (JP, A) Japanese Utility Model Unexamined Publication No. 5-4654 (JP, U) (58) Field surveyed (Int.Cl. ⁷ , DB name) H04L 12/28 H04L 12/56 H04L 1/00 H04L 29/14 H04B 7/26

Claims (15)

(57) [Claims] 1. A terminal and a base station transmit data via a wireless link section.
When transferring data, the quality of the transferred data is low.
Transfer the data if the data loss occurs.
And the quality of the data does not improve
Stop the data transfer if, Initially the connection information for the terminal where the transfer has stopped
And release the connection Day characterized by
Data transfer control method. 2. A method in which control data is transmitted from a base station to a terminal, and a state in which the control data does not return from the terminal after a lapse of a predetermined time is determined as a state in which the quality of the transferred data is not improved. 2. The data transfer control method according to claim 1, wherein: 3. A control data is transmitted from a base station to a terminal, a bit error rate of the control data returned from the terminal is measured, and a state in which the bit error rate becomes equal to or less than a predetermined threshold is determined. 3. The data transfer control method according to claim 1, wherein a state that continues for a time is determined as a state in which the quality of the transferred data is not improved. 4. A terminal, a base station for transferring data between the terminal and a wireless link section, and data transfer control for retransmitting the data when the data loss occurs in the wireless link section. Unit, and time measuring means for measuring time, and measuring the quality of data transferred in the wireless link section,
A wireless quality measuring unit for stopping the transfer of the data when the quality of the measured data is not improved even after a lapse of a predetermined period of time measured by the timing unit, and a connection to a terminal where the transfer is stopped. Means for initializing information and releasing the connection. 5. The wireless quality measuring unit transmits control data from a base station to a terminal, and sets a state in which the control data does not return from the terminal even after a predetermined time elapses. 5. The data transfer control device according to claim 4, wherein it is determined that the condition is not improved. 6. The radio quality measuring unit transmits control data from a base station to a terminal, measures a bit error rate of the control data returned from the terminal, and the bit error rate is set in advance. 6. The data transfer control device according to claim 4, wherein a state in which the state degraded from the threshold value continues for a predetermined time is determined as a state in which the quality of the transferred data is not improved. 7. The ATM cell charging / counting control unit which performs a charging / counting process for a connection having a deteriorated transmission quality before stopping the transmission of user communication data to the ATM backbone network, before stopping the transmission of the user communication data to the ATM backbone network. 7. The data transfer control device according to claim 6, further comprising: an OAM processing unit that generates an OAM cell carrying the counted non-charging cell information and sends the generated OAM cell to a subsequent ATM switch. 8. The ATM charging counting control unit calculates an identifier of a connection in which a cell loss has occurred, the number of lost cells, the number of retransmission controls, and the number of retransmission cells as non-charging cell information. The data transfer control device as described in the above. 9. The ATM switch includes a charging device for measuring the number of non-charging cells from an OAM cell carrying non-charging cell information received from a base station, and subtracting a cell to be non-charging from the number of cells passing through the connection. 9. The data transfer control device according to claim 7, further comprising a call processor that performs a call processing. 10. A first data transfer control device for converting received data into a frame and transmitting the data to a radio channel section, and a second device for decomposing the frame received from the first data transfer control device into data and performing communication. In the data transfer network including the data transfer control device, the second data transfer control device monitors a frame received from the first data transfer control device to detect data loss, Control means for requesting retransmission of the data triggered by detection of data loss, and quality measuring means for measuring quality of a radio link section for the first data transfer control device, wherein the quality measuring means Is characterized by comprising a first measuring means for measuring continuous data quality deterioration and a second measuring means for detecting deterioration occurring in a short time. The data transfer control device. 11. The second measuring means includes means for transmitting a frame including control data from the second data transfer control device and causing the first data transfer control device to loop back the frame. 11. The data transfer control device according to claim 10, comprising: 12. The control data included in a frame including the control data includes connection information necessary for looping back the frame by the first data transfer control device. Data transfer control device. 13. A first data transfer control device for assigning a sequence number and an identifier indicating the beginning of a message to an ATM cell, forming a frame, and transmitting the frame to a radio channel section, said first data transfer control device. And a second data transfer control device for decomposing the frame received from the ATM cell into an ATM cell and transferring the ATM cell to a subsequent switch, wherein the second data transfer control device comprises: A means for monitoring a frame received from the device, detecting a loss of a cell, a control means for requesting retransmission of the data, triggered by the detection of the loss of the data, and a first data transfer control device, A quality measuring unit for measuring the quality of the radio link section, wherein the quality measuring unit further includes a first measuring unit for measuring continuous data quality degradation; The data transfer control apparatus characterized by being configured to include a second measuring means for detecting a deterioration occurrence time. 14. An ATM cell including a sequence number and an identifier indicating the beginning of a message is framed,
A first data transfer control device for transmitting to a wireless link section;
A second data transfer control device that decomposes the frame received from the ATM terminal into ATM cells and transfers the ATM cell to a subsequent switch, wherein the second data transfer control device is A reading unit that reads the received frame in units of cells, and a determining unit that monitors the loss of the cell and determines retransmission of the cell and release of the connection. In the case of release, it is necessary to have a means for counting the number of cells from the head cell of the message to which the missing cell belongs to the missing cell, notifying the subsequent exchange, and stopping cell transmission after the missing cell data. Characteristic data transfer control device. 15. The data transfer control device according to claim 10, wherein said frame is a TDMA frame, and a plurality of ATM cells are multiplexed and transmitted in a data area thereof.