WO2016015418A1

WO2016015418A1 - Service processing method and apparatus

Info

Publication number: WO2016015418A1
Application number: PCT/CN2014/092179
Authority: WO
Inventors: 薛蓉; 汪奇
Original assignee: 中兴通讯股份有限公司
Priority date: 2014-07-28
Filing date: 2014-11-25
Publication date: 2016-02-04
Also published as: CN105323035A

Abstract

Disclosed are a service processing method and apparatus. The method comprises: determining the maximum number of times of frame retransmission and the number of times of tolerance of frame sequence number faults (S102); during the transmission process of each frame, recording the number of times of retransmission of the frame and the number of times of sequence number faults of the frame (S104); and according to a comparison result between the number of times of retransmission and the maximum number of times of frame retransmission or a comparison result between the number of times of sequence number faults and the number of times of tolerance of frame sequence number faults, determining to retransmit the frame or interrupt the service (S106). By means of the present invention, the problem of poor performance of a data transmission mechanism of a data link layer in the related art is solved, the call drop rate of a system is reduced, the success rate of MS handovers is increased, the data transmission performance of the data link layer is improved, the tolerance capability of the system is enhanced, and the use feeling of a user is improved.

Description

Business processing method and device

Technical field

The present invention relates to the field of mobile communications, and in particular, to a service processing method and apparatus.

Background technique

The mobile communication system uses a simplified protocol similar to the OSI (Open System Interconnection) protocol model, including the physical layer (L1), the data link layer (L2), and the network layer (L3). The physical layer is the lowest layer of the protocol model and provides all the functions required for the physical medium to transport the bitstream. The data link layer establishes an error-free transmission by establishing a data link between adjacent nodes based on the physical layer providing a bitstream service. The network layer includes various types of messages and programs to control the business.

In order to make an error occur in the transmission, the Data Link Layer only retransmits the finite data with errors, and combines the bit streams into frames. In addition to the data to be transmitted, each frame includes a check code to enable the receiver to discover errors in the transmission. Once the frame synchronization error is determined, the retransmission method is used to correct, that is, the sender can only consider that the frame has been correctly transmitted after receiving the feedback signal that the receiver has correctly received, otherwise it needs to be resent. In addition, the burst noise of the physical layer may cause the entire data frame or feedback information frame to be lost, which will cause the sender to never receive the feedback information sent by the receiver, thereby stalling the transmission process.

In order to avoid this situation, a timer is introduced to limit the time interval for the receiver to send back feedback information. When the sender sends a frame, the timer is started. If the receiver does not receive the feedback information within the limited time interval, That is, if the timer expires, the transmitted frame is considered to be in error or lost and needs to be resent. Since the same frame data may be repeatedly transmitted multiple times, it may cause the receiver to receive the same frame multiple times and hand it over to the network layer. In order to prevent this danger, a sequence number is assigned to each frame sent, so that the receiver can distinguish whether it is a newly transmitted frame or a frame that has been received but retransmitted from the sequence number. The received frame is delivered to the network layer.

Taking the GSM (Global System for Mobile Communications) network as an example, the call and hang up of the MS (Mobile Station) includes the establishment and release process of the data link layer on the radio interface. The Frame Response and the UA (Unnumbered Acknowledgement) frame response of the SABM (Set Asynchronous Balanced Mode) indicate that the MS and the BTS (Base Transceiver Station) are chained at the data link layer, DISC (DISConnect, broken) Open connection) Frame transmission and UA frame response indicate that the MS and BTS are released at the data link layer, and the intermediate hold process of establishment and release is actually segmentation/ The transmission of an I (Information, Information Frame) frame or a UI (Unnumbered Information) frame that is not segmented.

Although the existing data link layer data transmission mechanism ensures data-free error transmission, due to the rapid development of the city, a large number of dense high-rise buildings and road tunnels are increasing, and coverage needs to be completed through a distributed system, and the wireless environment is more complicated, thus resulting in wireless In the data transmission of the port, the chances of loss or interference of multi-frame operation information are increased synchronously, and the abnormal call drop of the system is inevitable. For example, the SAMB frame, the DISC frame or the I frame is sent after the timer is set, and wait until the timer expires. If the corresponding response frame is not received, the SAMB frame, the DISC frame, or the I frame is resent, and the maximum retransmission is N200 times, which exceeds N200 times of terminating the service; or when the I frame receives the response frame sequence number error, the service is terminated. Therefore, based on the existing data link layer data transmission mechanism, the system has poor fault tolerance, and the user experience is poor, and the call drop rate is high.

In view of the poor performance of the data link layer data transmission mechanism in the related art, an effective solution has not been proposed yet.

Summary of the invention

The embodiment of the invention provides a service processing method and device, so as to at least solve the problem that the performance of the data link layer data transmission mechanism in the related art is poor.

According to an aspect of the present invention, an embodiment of the present invention provides a service processing method, where the method includes: determining a maximum number of retransmissions of a frame and a number of error tolerances of a frame serial number; and recording the frame during transmission of each frame. The number of retransmissions and the number of errors in the sequence number; based on the comparison result of the number of retransmissions and the maximum number of retransmissions of the frame, or the comparison result of the number of error numbers and the number of error tolerances of the frame number, it is determined that the frame is retransmitted or the service is interrupted.

Preferably, determining the maximum number of retransmissions of the frame and the number of error tolerances of the frame serial number includes: setting a data link layer configuration switch; setting a maximum number of retransmissions of the frame and a number of error tolerances of the frame serial number when the data link layer configuration switch is turned on; When the link layer configuration switch is turned off, the value of the maximum number of retransmissions of the frame and the number of error tolerances of the frame number is determined as the value specified in the communication protocol.

Preferably, based on the comparison result of the number of retransmissions and the maximum number of retransmissions of the frame, or the comparison result of the number of error numbers and the number of error tolerances of the frame number, determining whether to resend the frame or interrupting the service, including: during the transmission of each frame If the acknowledgment frame is not received, compare the number of retransmissions and the maximum number of retransmissions of the frame. If the number of retransmissions < the maximum number of retransmissions of the frame, resend the frame, otherwise the service is interrupted; during the transmission of each frame, If the serial number is wrong, the sequence number error number and the frame number error tolerance number are compared. If the sequence number error number < frame number error tolerance number, the frame is retransmitted, otherwise the service is interrupted.

Preferably, the application range of the method is a site level, a cell level, or a carrier frequency level.

According to another aspect of the present invention, an embodiment of the present invention further provides a service processing apparatus, where the apparatus includes: a value determining module, configured to determine a maximum number of retransmissions of a frame and a number of error tolerances of a frame serial number; It is set to record the number of retransmissions and the number of sequence errors of the frame during the transmission process of each frame; the service processing module is set to a comparison result based on the number of retransmissions and the maximum number of retransmissions of the frame, or the number of sequence errors and the frame number The result of the comparison of the number of error tolerances determines whether to resend the frame or interrupt the service.

Preferably, the value determining module comprises: a switch setting unit configured to set a data link layer configuration switch; and a first setting unit configured to set a frame maximum retransmission number and a frame serial number error tolerance when the data link layer configuration switch is turned on The second setting unit is configured to determine the value of the maximum number of retransmissions of the frame and the number of error tolerances of the frame serial number when the data link layer configuration switch is turned off, as the value specified in the communication protocol.

Preferably, the service processing module includes: a retransmission processing unit, configured to compare the number of retransmissions and the maximum number of retransmissions of the frame if the number of retransmissions is the largest in the transmission process of each frame, if the acknowledgement frame is not received, If the number of retransmissions is repeated, the frame is retransmitted, otherwise the service is interrupted; the fault-tolerant processing unit is set to compare the sequence number error number and the frame number error tolerance number if the sequence number is incorrect during the transmission of each frame, if the sequence number is incorrect <If the frame number is incorrectly fault tolerant, the frame will be resent, otherwise the service will be interrupted.

Preferably, the application range of the above device is a site level, a cell level, or a carrier frequency level.

The beneficial effects of the present invention are as follows:

The invention solves the problem that the performance of the data link layer data transmission mechanism in the related art is poor, reduces the system call drop rate, improves the MS handover success rate, improves the data transmission performance of the data link layer, and enhances the performance. The fault tolerance of the system improves the user's feeling of use.

The above description is only an overview of the technical solutions of the present invention, and the above-described and other objects, features and advantages of the present invention can be more clearly understood. Specific embodiments of the invention are set forth below.

DRAWINGS

1 is a flowchart of a service processing method according to an embodiment of the present invention;

2 is a schematic diagram of an operating system according to an embodiment of the present invention;

3 is a schematic diagram of RC and EC statistics according to an embodiment of the present invention;

4 is a schematic diagram of service processing of a data link layer according to Embodiment 1 of the present invention;

FIG. 5 is a schematic diagram of service processing of a data link layer according to Embodiment 2 of the present invention; FIG.

6 is a schematic diagram of service processing of a data link layer according to Embodiment 3 of the present invention;

FIG. 7 is a structural block diagram of a service processing apparatus according to an embodiment of the present invention.

detailed description

In order to solve the problem of poor performance of the data link layer data transmission mechanism in the prior art, the present invention provides a service processing method and apparatus. The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

This embodiment provides a service processing method, which can be implemented in a data link layer. FIG. 1 is a flowchart of a service processing method according to an embodiment of the present invention. As shown in FIG. 1, the method includes the following steps (steps). S102-Step S106):

Step S102, determining the maximum number of retransmissions of the frame and the number of error tolerances of the frame serial number.

In this step, the value of the maximum number of retransmissions of the frame and the number of error tolerances of the frame number may be set according to the actual operation, or may be set to a value specified in the communication protocol. Based on this, the embodiment provides a preferred embodiment. , that is, set the data link layer configuration switch; set the maximum number of retransmissions of the frame and the number of error tolerances of the frame serial number when the data link layer configuration switch is turned on; and the maximum number of retransmissions of the frame when the data link layer configuration switch is turned off And the value of the frame number error tolerance number is determined as the value specified in the communication protocol.

In general, the value of the maximum number of retransmissions of the frame and the number of error tolerances of the frame number is set to be higher than the value specified in the communication protocol. In this way, the chances of resending the frame increase, and the chances of receiving the response frame or the sequence number of the correct frame are increased synchronously, so that the probability of service interruption is reduced, and the system call drop rate is reduced.

Step S104, in the process of transmitting each frame, record the number of retransmissions and the number of sequence errors of the frame.

Step S106, determining whether to resend the frame or interrupt the service based on a comparison result of the number of retransmissions and the maximum number of retransmissions of the frame, or a comparison result of the number of error numbers and the number of error tolerances of the frame number.

In this step, when the frame transmission is not smooth, different numerical comparisons are performed based on different reasons, specifically:

During the transmission of each frame, if the acknowledgment frame is not received, the number of retransmissions and the maximum number of retransmissions of the frame are compared. If the number of retransmissions < the maximum number of retransmissions of the frame, the frame is retransmitted, otherwise the service is interrupted; When the service is interrupted, the error report that the cause value is the timer timeout can be reported.

In the process of sending each frame, if the serial number is wrong, the serial number error number and the frame serial number error tolerance number are compared. If the serial number error number < frame number error tolerance number, the frame is retransmitted, otherwise the service is interrupted; When the reason value is reported, the error value of the serial number error can be reported.

Preferably, the application range of this embodiment may be a site level, a cell level, or a carrier frequency level.

With the embodiment, the problem of poor performance of the data link layer data transmission mechanism in the related art is solved, the system call drop rate is reduced, the MS handover success rate is improved, and the data transmission performance of the data link layer is improved. The fault tolerance of the system improves the user's feeling of use.

The technical solution of the invention reduces the system call drop rate, improves the network performance and increases the user's feeling goodness on the basis of ensuring the data link layer data transmission error-free, and the specific steps are as follows:

Step 1: Set the data link layer configuration switch through the background, and the maximum number of retransmissions and the number of error tolerances of the frame number.

Step 2: If the data link layer configuration switch is enabled, the maximum number of retransmissions of the delivered frame will be cached, denoted as N, and the frame serial number error tolerance cache will be recorded as M. If the background data link layer configuration switch is turned off, N and M are the values specified by the relevant communication protocol.

Step 3: When the service is initiated, a timer is set at the same time as each frame is sent, and it is determined that the corresponding confirmation frame is received within the set time interval, and the confirmation frame number is correct, otherwise the frame is retransmitted, and the frame is recorded. The number of retransmissions RC and the number of retransmission errors EC.

Step 4: If the acknowledgment frame is not received, the frame can be resent if RC<N is satisfied, otherwise the cause value is reported as an error report of the timer timeout, thereby interrupting the service. If the serial number is wrong, the frame can be resent if EC<M is satisfied, otherwise the cause value is reported as an error report with the serial number error, thereby interrupting the service.

In this method, the application of the data link layer configuration switch and the maximum number of retransmissions of the frame and the number of error tolerances of the frame number are not limited to the site level, and may be cell or carrier frequency.

Further, the method is not only for the BTS trial, but also for the MS trial.

Further, the maximum number of retransmissions of the background configuration frame and the number of error tolerances of the frame serial number are also applicable to other communication systems such as GPRS (General Packet Radio Service).

Under normal circumstances, the background uses the configured data link layer frame maximum retransmission times and frame serial number error tolerance times, which is larger than the value defined in the protocol. According to the fourth step, the retransmission frame opportunity increases, and the response frame is received. Or the chance of the correct frame number is increased synchronously, and the probability of service interruption is reduced, that is, the system call drop rate is reduced.

The technical solution of the present invention will be described below by way of preferred embodiments and the accompanying drawings.

In this embodiment, the BTS of the GSM communication system is taken as an example to introduce a method for improving the performance of the data link layer. 2 is a schematic diagram of an operating system according to an embodiment of the present invention. As shown in FIG. 2, the data link layer configuration switch is first turned on in the background, and the maximum number of retransmissions of the frame and the number of error tolerances of the frame serial number are set. The configuration is delivered to the BTS, and the maximum number of retransmissions of the frame and the number of error tolerances of the frame number are saved to N and M, respectively. The GSM-related protocol (3GPP TS 44.006) specifies that N is N200 (different channel types N200 values are different, for example, 5 for SACCH channel N200, 23 for SDCCH channel N200, etc.), and M is 0. In this embodiment, N and M are configured as N200+3 and 3. After the service is initiated, the data link layer of the BTS and the MS has a large number of multi-frame operation transmission data, and the data link layer of the BTS counts the number of retransmissions per frame RC and the number of frames sequence error EC, and establishes multiple instances for multiple services. Each instance has its own RC and EC statistics, as shown in Figure 3 for the RC and EC statistics diagrams. Taking the telephone service as an example, when there is only one telephone service, RC[0] and EC[0 are recorded for the telephone service. ], when there are multiple telephone services, RC[1] and EC[1], RC[2], and EC[2]...RC[n] and EC[n] can be recorded in sequence.

The service of the data link layer is confirmed by the transmission of the SAMB frame and the response of the UA. Figure 4 is a schematic diagram of the service processing of the data link layer according to the first embodiment of the present invention. As shown in Figure 4, the class label changes and the encryption mode. Information such as encryption completion is transmitted to the opposite end through the I frame at the data link layer. Taking encryption as an example, the RC and EC are both 0 before the encryption mode is transmitted, and the parameters N(S)=0 and N(R)=1 are the sequence numbers carried by the frame, that is, the check code. After the encryption mode is sent, V(S)=1, V(R)=1, and V(A)=0 is used to check whether the next received I frame or RR frame sequence number is correct, specifically satisfying (N(R). ) -V(A)) mod 8<=(V(S)-V(A)) mod 8 indicates that the frame number is correct and the information is transmitted correctly. In FIG. 4, the encryption is completed, that is, the information frame is also an acknowledgement frame for the encryption mode, and the encryption completion carries the sequence numbers N(S)=1 and N(R)=1, satisfying (N(R)-V(A)) mod 8 <=(V(S)-V(A)) mod 8, as follows:

(N(R)-V(A)) mod 8<=(V(S)-V(A)) mod 8

(1-0) mod 8<=(1-0)mod 8

1<=1

1<=1 is established, that is, the frame number serial number is correct, and RC and EC remain at 0.

Continue to deliver the next frame of content, that is, TMSI redistribution.

Similarly, FIG. 5 is a schematic diagram of service processing of the data link layer according to Embodiment 2 of the present invention. As shown in FIG. 5, if an error frame is received after the encryption mode is sent, the parameters are N(S)=0 and N. (R)=3, which does not satisfy (N(R)-V(A)) mod 8<=(V(S)-V(A)) mod 8, as follows:

(N(R)-V(A)) mod 8<=(V(S)-V(A)) mod 8

(3-0) mod 8<=(1-0)mod 8

3<=1

3<=1 does not hold, that is, the frame number is incorrect. First, it is judged whether EC<M is established, that is, 0<3 is established, the frame retransmission condition is satisfied, and the encryption mode frame is retransmitted, and the parameters N(S)=0, N(R)=1, V(S)=1, V( R) = 1, V(A) = 0 remains unchanged, and EC is increased by 1 in this embodiment.

The MS sends an encryption to the BTS to complete the I frame piggyback confirmation. The carried sequence numbers are N(S)=1 and N(R)=1, and the check sequence number is:

(N(R)-V(A)) mod 8<=(V(S)-V(A)) mod 8

(1-0) mod 8<=(1-0)mod 8

1<=1

1<=1 is established, the frame number serial number is correct, and the EC is cleared to 0.

Continue to deliver the next frame of content, that is, TMSI redistribution.

In this embodiment, if the existing data link layer data transmission mechanism is adopted, when the error frame is verified and the serial number is incorrect, the cause value is immediately reported as an error report of the serial number error, thereby immediately interrupting the service. With the method provided in this embodiment, when the error frame is received, the encryption mode can be resent, and then the correct I frame is received, the service continues, and the MS maintains the call state.

Similarly, FIG. 6 is a schematic diagram of service processing of the data link layer according to Embodiment 3 of the present invention. As shown in FIG. 6, the BTS encryption mode does not receive the response frame of the MS, and waits until the timer is set when the frame is sent. After the timeout, it is judged that RC<N, that is, 0<N200+3, and then the frame is resent, the parameters N(S)=0, N(R)=1, V(S)=1, V(R)=1, V(A)=0 remains unchanged and the RC increase becomes 1.

This is retransmitted until the RC becomes N200+2, that is, the frame is retransmitted N200+2 times before receiving the response frame of the MS. Obviously, if the existing data link layer data transmission mechanism is adopted, when the encryption mode retransmits the RC to N200, since the response frame of the MS is still not received, the reported cause value is an error report of the timer timeout, thereby interrupting the industry. Business. If the method provided in this embodiment is used, the encryption mode can be retransmitted until the RC is N200+2, and the response of the MS is received, the service continues to be executed, and the MS maintains the call state.

If the above situation occurs in the cell handover process, the method provided in this embodiment can improve the MS handover success rate, and the user can cut a cell with a good signal to improve the user experience.

Corresponding to the service processing method introduced in the foregoing embodiment, this embodiment provides a service processing apparatus, which is used to implement the foregoing embodiment. FIG. 7 is a structural block diagram of a service processing apparatus according to an embodiment of the present invention. As shown in FIG. 7, the apparatus includes: a numerical value determining module 10, a number recording module 20, and a service processing module 30. The structure is described in detail below.

The numerical determination module 10 is configured to determine a maximum number of retransmissions of the frame and a number of error tolerances of the frame serial number;

The number recording module 20 is connected to the numerical value determining module 10, and is configured to record the number of retransmissions and the number of serial errors of the frame during the transmission of each frame;

The service processing module 30 is connected to the number-of-times recording module 20, and is configured to determine the retransmission of the frame or the interrupt service based on the comparison result of the number of retransmissions and the maximum number of retransmissions of the frame, or the comparison result of the number of error numbers and the number of error tolerances of the frame number. .

In this embodiment, the numerical value determining module 10 includes: a switch setting unit configured to set a data link layer configuration switch; and a first setting unit configured to set a maximum number of retransmissions of the frame when the data link layer configuration switch is turned on And the frame number error tolerance number; the second setting unit is configured to determine the value of the maximum number of retransmissions of the frame and the number of error tolerances of the frame number when the data link layer configuration switch is turned off, as the value specified in the communication protocol.

The service processing module 30 includes: a retransmission processing unit configured to compare the number of retransmissions and the maximum number of retransmissions of the frame if the number of retransmissions is greater than the maximum number of retransmissions in the transmission process of each frame. If the number of times is sent, the frame is resent, otherwise the service is interrupted; the fault-tolerant processing unit is set to compare the sequence number error number and the frame number error tolerance number if the serial number is wrong during the transmission of each frame, if the sequence number error number < If the frame sequence number is incorrectly fault tolerant, the frame is retransmitted, otherwise the service is interrupted.

In this embodiment, the application range of the foregoing device is a site level, a cell level, or a carrier frequency level.

It can be seen from the above description that, by the technical solution of the present invention, the maximum number of retransmissions of the frame and the number of error tolerances of the frame serial number are adjusted, so that the chances of resending the frame are increased, and the chances of receiving the response frame or the correct frame number are increased synchronously, so that the service is interrupted. The probability of the system is reduced, and the system call drop rate is lowered, thereby improving the system performance and improving the user's feeling of use.

While the preferred embodiments of the present invention have been disclosed for purposes of illustration, those skilled in the art will recognize that various modifications, additions and substitutions are possible, and the scope of the invention should not be limited to the embodiments described above.

Industrial applicability

As described above, the service processing method and apparatus provided by the embodiments of the present invention have the following beneficial effects: by adjusting the maximum number of retransmissions of the frame and the number of error tolerances of the frame serial number, the retransmission frame opportunity is increased, and the response frame or sequence is received. The chance of correct frame synchronization increases, which reduces the probability of service interruption and reduces the system call drop rate, which improves system performance and user experience.

Claims

A business processing method, the method comprising:

Determining the maximum number of retransmissions of the frame and the number of error tolerances of the frame number;

During the transmission of each frame, the number of retransmissions and the number of sequence errors of the frame are recorded;

And determining, according to the comparison result of the number of retransmissions and the maximum number of retransmissions of the frame, or the comparison result of the number of error numbers and the number of error tolerances of the frame number, determining to resend the frame or interrupt the service.
The method of claim 1, wherein determining the maximum number of retransmissions of the frame and the number of error tolerances of the frame serial number comprises:

Set the data link layer configuration switch;

When the data link layer configuration switch is turned on, setting a maximum number of retransmissions of the frame and a number of error tolerances of the frame serial number;

When the data link layer configuration switch is turned off, the value of the maximum number of retransmissions of the frame and the number of error tolerances of the frame serial number is determined as a value specified in the communication protocol.
The method according to claim 1, wherein the retransmission is determined based on a comparison result of the number of retransmissions and the maximum number of retransmissions of the frame, or a comparison result of the number of error numbers and the number of error tolerances of the frame number The frame or interrupt service, including:

During the transmission of each frame, if the acknowledgment frame is not received, the number of retransmissions and the maximum number of retransmissions of the frame are compared. If the number of retransmissions < the maximum number of retransmissions of the frame, the frame is retransmitted, otherwise Interrupt business;

During the transmission of each frame, if the serial number is wrong, the number of the serial number error and the number of error tolerances of the frame serial number are compared. If the serial number error number < frame number error tolerance number, the frame is retransmitted, otherwise the service is interrupted. .
The method according to any of claims 1 to 3, wherein the application range of the method is a site level, a cell level, or a carrier frequency level.
A service processing device, the device comprising:

a numerical determination module configured to determine a maximum number of retransmissions of the frame and a number of error tolerances of the frame serial number;

The number recording module is configured to record the number of retransmissions and the number of sequence errors of the frame during the transmission of each frame;

The service processing module is configured to determine to resend the frame or interrupt the service based on a comparison result of the number of retransmissions and the maximum number of retransmissions of the frame, or a comparison result of the number of error numbers and the number of error tolerances of the frame sequence number .
The apparatus of claim 5 wherein said numerical value determining module comprises:

a switch setting unit configured to set a data link layer configuration switch;

a first setting unit, configured to set a maximum number of retransmissions of the frame and a number of error tolerances of the frame serial number when the data link layer configuration switch is turned on;

The second setting unit is configured to determine, when the data link layer configuration switch is turned off, a value of the maximum number of retransmissions of the frame and the number of error tolerances of the frame serial number as a value specified in a communication protocol.
The apparatus of claim 5 wherein said service processing module comprises:

The retransmission processing unit is configured to compare the number of retransmissions and the maximum number of retransmissions of the frame if the acknowledgment frame is not received during the transmission of each frame, and if the number of retransmissions is < the maximum number of retransmissions of the frame, Then resend the frame, otherwise the service is interrupted;

The fault-tolerant processing unit is configured to compare the serial number error number and the frame serial number error tolerance number if the serial number is wrong during the transmission of each frame, and resend if the serial number error number < frame serial number error tolerance number The frame, otherwise interrupts the service.
The apparatus according to any one of claims 5 to 7, wherein the application range of the apparatus is a station level, a cell level, or a carrier frequency level.