CN102404098A - D channel uplink access procedure transmission method and device - Google Patents

Abstract

The invention provides a method and a device for transmitting a link access procedure on a D channel, belonging to the field of mobile communication. The method for transmitting the link access procedure on the D channel comprises the following steps: a transmission device receives an information frame sent by an opposite terminal; the transmission device updates a first variable stored by the transmission device according to the received information frame, wherein the first variable indicates the receiving condition of the transmission device on the information frame; and the transmission device adds the updated first variable into an acknowledgement frame or a negative frame and transmits the acknowledgement frame or the negative frame to the opposite end so that the opposite end can retransmit the information frame which is not received by the transmission device. The technical scheme of the invention can improve the retransmission efficiency of the information frame in the link access procedure on the D channel.

Description

D channel uplink access procedure transmission method and device

technical field

The invention relates to the field of mobile communication, in particular to a method and device for transmitting a D channel uplink access procedure.

Background technique

In the LAPD (Link Access Procedure of D-Channel, D-channel link access procedure) protocol, the receiving end sends an I frame (information frame) with the frame confirmation, RR frame, REJ frame or RNR frame to the opposite end. Confirm that the correct I frame has been received by the local end. The N(R) field in the sent I frame, RR frame, and REJ frame indicates that the sending sequence number sent by the peer end is N(R)-1 and N(R) The I frames before -1 have been received correctly; in the case that the sent data is not lost or only one frame of data is lost, such an algorithm will not have any problems, but if the lost sent data exceeds 2 frames, especially The sending sequence numbers of the lost frames are discontinuous, so the retransmission efficiency of such an algorithm is relatively low.

For example, A sends five consecutive I-frame messages to B, and their sending sequence numbers are n, n+1, n+2, n+3, n+4. For some reason, n+1 and n +3 is lost, when B receives n, n+2 and n+4, assuming that B first confirms to A through the REJ frame and requests retransmission, then B will send a REJ of N(R)=n+1 to A frame, indicating that all I frames including n and before n have been received, and it is expected that A retransmits the I frame with the sequence number n+1. At this time, A knows that the I frame with the sequence number n+1 is lost, and needs to report to B retransmits the I frame with the sequence number of n+1, but A does not know that n+3 is also lost, so A will only retransmit the I frame of n+1; after n+1 retransmission is successful, B receives The data from n to n+2 has been continuous, and the I frame with the sequence number n+3 is still missing at this time. If the B side uses the RR frame for confirmation at this time, B will send N(R)=n+3 to A. The RR frame means that all I frames including n+2 and n+2 have been received, and it is expected to obtain frame n+3, then A will retransmit the I frame with the sequence number n+3 after the retransmission timing expires . Therefore, if the lost transmission data exceeds 2 frames or more, especially if the transmission sequence numbers of the lost frames are discontinuous, multiple confirmation retransmissions are required to complete the retransmission of all lost information frames, resulting in a loss of retransmission efficiency in the LAPD protocol. relatively low.

Contents of the invention

The technical problem to be solved by the present invention is to provide a D channel uplink access procedure transmission method and device, which can improve the retransmission efficiency of information frames in the D channel uplink access procedure.

In order to solve the above technical problems, embodiments of the present invention provide technical solutions as follows:

On the one hand, a D channel uplink access procedure transmission method is provided, including:

The transmission device receives the information frame sent by the opposite end;

The transmission device updates a first variable stored by itself according to the received information frame, and the first variable indicates the reception status of the information frame by the transmission device;

The transmission device adds the updated first variable to the confirmation frame or the veto frame, and sends the confirmation frame or the veto frame to the peer end, so that the peer end can resend the information not received by the transmission device frame.

Wherein, the first variable is a first bitmap variable, and updating the first variable stored by the transmission device according to the received information frame includes:

The transmission device temporarily stores the received out-of-sequence information frame in its own receiving sliding window, and the nth bit in the first bitmap variable corresponds to the nth position in the receiving sliding window;

If there is an information frame in the nth position in the receiving sliding window, the transmission device will set the nth bit in the first bitmap variable to 1, if the nth position in the receiving sliding window If there is no information frame, the transmission device sets the nth bit in the first bitmap variable to 0.

The embodiment of the present invention also provides a D channel uplink access protocol transmission method, including:

The transmission device receives an acknowledgment frame or a veto frame sent by the opposite end, and the acknowledgment frame or veto frame indicates the reception of the information frame by the opposite end;

The transmission The device updates the acknowledgment variable V(A) at the local end to N(R), and updates the second variable stored by itself according to the bitmap field in the received acknowledgment frame or veto frame;

The transmission device resends the information frame not received by the opposite end according to the updated local-end acknowledgment variable V(A) and the second variable.

Wherein, the method also includes:

The transmission device receives an information frame or an RNR frame sent by the opposite end;

If the N(R) value in the information frame or RNR frame is greater than the confirmation variable V(A) of the local end, update the confirmation variable V(A) of the local end to N(R), and the second variable All valid bits are set to 1.

Wherein, the transmission device resending the information frame not received by the opposite end according to the updated local confirmation variable V(A) and the second variable includes:

The transmission device determines information frames not received by the opposite end according to the local confirmation variable V(A) and the second variable;

After the preset condition is met, the transmission device resends the information frame not received by the opposite end.

Wherein, the second variable is a second bitmap variable, and the transmission device determines that the information frame not received by the opposite end according to the local confirmation variable V(A) and the second variable includes:

The transmission device judges whether the bit in the second bitmap variable is 0, wherein the nth bit in the second bitmap variable corresponds to the transmission sequence number sent by the transmission device to the peer end last time, which is N (S)=V(A)+n information frame;

If the nth bit in the second bitmap variable is 0, then the transmission device judges that the opposite end has not received the transmission sequence number sent by the transmission device to the opposite end last time as N(S)=V(A )+n information frame.

Wherein, the acknowledgment frame is an RR frame, the veto frame is a REJ frame, and after the preset condition is satisfied, the transmission device resends the information frame not received by the opposite end including:

If the transmission device receives the REJ frame, after the time difference between the time when the transmission device sends the information frame with the transmission sequence number N(S)=V(A)+n and the current time exceeds the preset time, Resending the information frame with the transmission sequence number N(S)=V(A)+n to the opposite end;

If the transmission device receives the RR frame, after the retransmission timer of the transmission device expires, if the time of sending the information frame with the transmission sequence number N(S)=V(A)+n is different from the current When the time difference exceeds the preset time, the transmission device resends the information frame with the transmission sequence number N(S)=V(A)+n to the opposite end.

The embodiment of the present invention also provides a transmission device, including:

The receiving module is used to receive the information frame sent by the opposite end;

An update module, configured to update a first variable stored by itself according to the received information frame, the first variable indicating the reception of the information frame by the transmission device;

A sending module, configured to add the updated first variable to the confirmation frame or the veto frame, and send the confirmation frame or the veto frame to the peer end, so that the peer end can resend the information not received by the transmission device information frame.

Wherein, the first variable is a first bitmap variable, and the update module includes:

a storage submodule, configured to temporarily store the out-of-sequence information frames received by the receiving module in the receiving sliding window, and the nth bit in the first bitmap variable corresponds to the nth position in the receiving sliding window ;

A submodule is set, which is used to set the nth bit in the first bitmap variable to 1 if there is an information frame in the nth position in the receiving sliding window, and if the nth bit in the receiving sliding window If there is no information frame in position, the nth bit in the first bitmap variable is set to 0.

The embodiment of the present invention also provides a transmission device, including:

A receiving module, configured to receive an acknowledgment frame or a veto frame sent by the peer, where the acknowledgment frame or the veto frame indicates the reception of the information frame by the peer;

An updating module, configured to if the N(R) field in the acknowledgment frame or the veto frame is not less than the confirmation variable V(A) of the transmission device itself and not greater than the transmission state variable V(S) of the transmission device itself , then update the confirmation variable V(A) of the transmission device itself to N(R), and update the second variable stored in the transmission device according to the bitmap field in the received confirmation frame or veto frame ;

A sending module, configured to resend information frames not received by the opposite end according to the updated local-end acknowledgment variable V(A) and the second variable.

Wherein, the receiving module is also used to receive an information frame or an RNR frame sent by the opposite end;

The update module is also used to update the local confirmation variable V(A) to N if the N(R) value in the information frame or the RNR frame is greater than the local confirmation variable V(A) of the transmission device. (R), and set all valid bits of the second variable to 1.

Wherein, the sending module includes:

A determination submodule, configured to determine an information frame not received by the opposite end according to the local confirmation variable V(A) and the second variable;

The sending sub-module is used to resend the information frame not received by the opposite end after the preset condition is met.

Wherein, the second variable is a second bitmap variable,

The determination submodule is specifically used to determine whether the bit in the second bitmap variable is 0, wherein the nth bit in the second bitmap variable corresponds to the last transmission sent by the transmission device to the opposite end For an information frame whose sequence number is N(S)=V(A)+n, if the nth bit in the second bitmap variable is 0, it is judged that the opposite end has not received the information frame sent by the transmission device last time. The opposite end sends an information frame whose sequence number is N(S)=V(A)+n.

Wherein, the acknowledgment frame is an RR frame, the rejection frame is a REJ frame, and the sending submodule is specifically configured to send the transmission sequence number N to the transmission device if the transmission device receives the REJ frame (S)=V(A)+n After the time difference between the time of the information frame of V(A)+n and the current time exceeds the preset time, resend the information frame whose transmission sequence number is N(S)=V(A)+n to the target end;

If the transmission device receives the RR frame, after the retransmission timer of the transmission device expires, if the transmission device sends the information frame whose transmission sequence number is N(S)=V(A)+n If the time difference between the time and the current time exceeds the preset time, then resend the information frame with the transmission sequence number N(S)=V(A)+n to the opposite end.

The technical solution of the present invention has the following beneficial effects:

In the above solution, the transmission device sets the first variable stored by itself according to the received information frame, and adds the first variable to the confirmation frame or the veto frame and sends it to the peer end to inform the peer end of the local reception situation. The transmission device at the opposite end can resend the information frame whose transmission failed according to the received confirmation frame or veto frame. In the present invention, when the sender loses more than 2 frames of information, especially when the sending sequence numbers of the lost frames are discontinuous, the receiver can inform the sender what information has been lost through a confirmation frame or a veto frame. Frames do not need to be confirmed by both parties for multiple retransmission interactions, but can complete the retransmission of all lost information frames through one retransmission interaction, thereby improving the efficiency of retransmission.

Description of drawings

FIG. 1 is a schematic flowchart of a method for transmitting an uplink access procedure on a D channel according to an embodiment of the present invention;

FIG. 2 is a schematic flowchart of a method for transmitting an uplink access procedure on a D channel according to an embodiment of the present invention;

3 is a schematic structural diagram of a transmission device according to an embodiment of the present invention;

4 is a schematic structural diagram of a transmission device according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of an RR frame structure according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of a REJ frame structure according to an embodiment of the present invention;

FIG. 7 is a schematic flow diagram of updating and sending rwnd_bitmap by transmission device A according to an embodiment of the present invention;

FIG. 8 is a schematic flow diagram of processing after receiving data by transmission device B according to an embodiment of the present invention;

FIG. 9 is a schematic diagram of the processing flow of the transmission device B after the retransmission timer of the transmission device B expires according to the embodiment of the present invention.

Detailed ways

In order to make the technical problems, technical solutions and advantages to be solved by the embodiments of the present invention clearer, the following will describe in detail with reference to the drawings and specific embodiments.

The embodiment of the present invention aims at the problem of low retransmission efficiency in the prior art LAPD protocol, and provides a D channel uplink access procedure transmission method and device, which can improve the efficiency of information frames in the D channel uplink access procedure. retransmission efficiency.

Fig. 1 is a schematic flow diagram of a method for transmitting an uplink access procedure on a D channel according to an embodiment of the present invention. As shown in Fig. 1 , this embodiment includes:

Step 101: the transmission device receives the information frame sent by the opposite end;

Step 102: The transmission device updates the first variable stored by itself according to the received information frame, and the first variable indicates the reception status of the information frame by the transmission device;

Step 103: The transmission device adds the updated first variable to the confirmation frame or the rejection frame, and sends the confirmation frame or the rejection frame to the peer end, so that the peer end can resend the information frame not received by the transmission device.

In the D channel uplink access procedure transmission method of the embodiment of the present invention, the transmission device of the receiving party sets the first variable stored by itself according to the received information frame, and adds the first variable to the confirmation frame or the veto frame and sends it to The peer end, to inform the peer end of the local receiving situation. In this embodiment, when the sender loses more than 2 information frames, especially when the sending sequence numbers of the lost frames are discontinuous, the receiver can inform the sender which information frames are lost at once through the confirmation frame or the veto frame. The information frame does not need to be retransmitted through multiple confirmations by both parties, but can complete the retransmission of all lost information frames through one retransmission interaction, thereby improving the efficiency of retransmission.

Fig. 2 is a schematic flow diagram of a method for transmitting an uplink access procedure on a D channel according to an embodiment of the present invention. As shown in Fig. 2, this embodiment includes:

Step 201: The transmission device receives the confirmation frame or the rejection frame sent by the opposite end, and the confirmation frame or the rejection frame indicates the reception status of the information frame by the opposite end;

Step 202: If the N(R) field in the acknowledgment frame or the veto frame is not less than the confirmation variable V(A) of the transmission device itself and not greater than the sending state variable V(S) of the transmission device itself, then the transmission device sends the confirmation variable V(S) of the transmission device itself The variable V(A) is updated to N(R), and the second variable stored by itself is updated according to the received confirmation frame or the bitmap field in the veto frame;

Step 203: The transmission device resends the information frame not received by the opposite end according to the updated local acknowledgment variable V(A) and the second variable.

Among them, if the transmission device receives the information frame or RNR frame sent by the opposite end, if the N(R) value in the information frame or RNR frame is greater than the confirmation variable V(A) of the local end, the transmission device will confirm the variable V(A) of the local end Update to N(R), and set all valid bits of the second variable to 1.

In the D channel uplink access procedure transmission method of the embodiment of the present invention, the transmission device of the sender learns the reception status of the receiver's information frame according to the received confirmation frame, veto frame, information frame and RNR frame. In this embodiment, when the sender loses more than 2 information frames, especially when the sending sequence numbers of the lost frames are discontinuous, the sender can know which information frames are lost in the transmission through the confirmation frame or the veto frame. The information frame does not need to be retransmitted through multiple confirmations by both parties, but can complete the retransmission of all lost information frames through one retransmission interaction, thereby improving the efficiency of retransmission.

Fig. 3 is a schematic structural diagram of a transmission device according to an embodiment of the present invention. As shown in Fig. 3, this embodiment includes:

The receiving module 30 is configured to receive the information frame sent by the opposite end;

The update module 31 is configured to update the first variable stored by itself according to the received information frame, and the first variable indicates the reception of the information frame by the transmission device;

The sending module 32 is configured to add the updated first variable to the confirmation frame or the veto frame, and send the acknowledgment frame or the veto frame to the peer end, so that the peer end can resend the information frame not received by the transmission device.

Wherein, the first variable is the first bitmap variable, and the update module 31 includes:

The storage submodule is used to temporarily store the out-of-sequence information frame received by the receiving module 30 in the receiving sliding window, and the nth bit in the first bitmap variable corresponds to the nth position in the receiving sliding window;

Set the sub-module, which is used to set the nth bit in the first bitmap variable to 1 if there is an information frame in the nth position in the receiving sliding window, and if there is no information frame in the nth position in the receiving sliding window information frame, set the nth bit in the first bitmap variable to 0.

Wherein, the confirmation frame is an RR frame, and the REJ frame is rejected. The sending module 32 is specifically used to place the first bitmap variable into the bitmap field in the RR frame or the REJ frame, and then send the RR frame or the REJ frame to the corresponding end.

The transmission device of the embodiment of the present invention is the receiver of the information frame in the LAPD link, sets the first variable stored by itself according to the received information frame, and adds the first variable to the confirmation frame or the veto frame and sends it to the target end to inform the other end of the local reception situation. In this embodiment, when the sender loses more than 2 information frames, especially when the sending sequence numbers of the lost frames are discontinuous, the receiver can inform the sender which information frames are lost at once through the confirmation frame or the veto frame. The information frame does not need to be retransmitted through multiple confirmations by both parties, but can complete the retransmission of all lost information frames through one retransmission interaction, thereby improving the efficiency of retransmission.

Fig. 4 is a schematic structural diagram of a transmission device according to an embodiment of the present invention. As shown in Fig. 4, this embodiment includes:

The receiving module 40 is configured to receive an acknowledgment frame or a veto frame sent by the peer, where the acknowledgment frame or the veto frame indicates the reception of the information frame of the peer;

The update module 41 is used to send the transmission device if the N(R) field in the confirmation frame or the veto frame is not less than the confirmation variable V(A) of the transmission device itself and not greater than the transmission state variable V(S) of the transmission device itself. The confirmation variable V(A) at the local end is updated to N(R). and updating the second variable stored by the transmission device according to the received confirmation frame or the bitmap field in the veto frame;

The sending module 42 is configured to resend information frames not received by the opposite end according to the updated local-end acknowledgment variable V(A) and the second variable.

Wherein, the receiving module 40 is also used to receive the information frame or RNR frame sent by the opposite end;

The update module 41 is also used to update the local confirmation variable V(A) to N(R) if the N(R) value in the information frame or the RNR frame is greater than the local confirmation variable V(A) of the transmission device, and All valid bits of the binary variable are set to 1.

Wherein, the confirmation frame is an RR frame, and the rejection frame is a REJ frame, and the update module 41 is specifically configured to save the bitmap field in the received RR frame or REJ frame into its second variable.

Wherein, sending module 42 comprises:

Determining the submodule, used to determine the information frame not received by the opposite end according to the local confirmation variable V (A) and the second variable;

The sending sub-module is used to resend the information frame not received by the opposite end after the preset condition is satisfied.

Wherein, the second variable is the second bitmap variable, and the determination submodule is specifically used to judge whether the bit in the second bitmap variable is 0, wherein, the nth bit in the second bitmap variable corresponds to the transmission device last sent If the information frame whose sequence number is N(S)=V(A)+n is sent to the opposite end, if the nth bit in the second bitmap variable is 0, then it is judged that the opposite end has not received the information frame sent by the transmission device last time. The opposite end sends an information frame whose sequence number is N(S)=V(A)+n.

The sending sub-module is specifically used for if the transmission device receives the REJ frame, after the time difference between the time when the transmission device sends the information frame with the transmission sequence number N(S)=V(A)+n and the current time exceeds the preset time, Resend the nth information frame to the peer;

If the transmission device receives the RR frame, after the retransmission timer of the transmission device expires, if the time difference between the time when the transmission device sends the information frame with the sequence number N(S)=V(A)+n and the current time exceeds After the preset time, resend the information frame with the sending sequence number N(S)=V(A)+n to the opposite end.

The transmission device in the embodiment of the present invention is the sender of the information frame in the LAPD link, and learns the receiving situation of the opposite end information frame according to the received confirmation frame or veto frame. In this embodiment, when the sender loses more than 2 information frames, especially when the sending sequence numbers of the lost frames are discontinuous, the sender can know which information frames are lost in the transmission through the confirmation frame or the veto frame. The information frame does not need to be retransmitted through multiple confirmations by both parties, but can complete the retransmission of all lost information frames through one retransmission interaction, thereby improving the efficiency of retransmission.

The following further introduces the method for transmitting the D channel uplink access procedure according to the embodiment of the present invention. In the present invention, the transmission devices at both ends of the LAPD link each retain the first variable and the second variable. The first variable is used to indicate the situation that the local end receives the information frame, and the second variable is used to indicate the situation that the opposite end receives the information frame.

After receiving the information frame, the transmission device sends an RR frame or REJ frame to the peer for confirmation, and the transmission device adds a bitmap field in the RR frame and the REJ frame, as shown in Figure 5, which is a schematic diagram of the structure of the RR frame in the present invention, and Figure 6 Shown is a schematic diagram of the REJ frame structure of the present invention. The first variable is carried in the bitmap field to inform the opposite end of the local reception of the information frame, and the transmission device at the opposite end updates the first variable carried in the bitmap field to its own second variable after receiving the RR frame or the REJ frame.

Wherein, the first variable may be the first bitmap variable rwnd_bitmap, and the second variable may be the second bitmap variable rcv_bitmap. rwnd_bitmap, used to identify the temporary storage of out-of-sequence information frames in the receiving sliding window of the local end, the nth bit of rwnd_bitmap corresponds to the nth position in the receiving sliding window, assuming that the size of the receiving sliding window agreed by the receiver and the sender is N _rwd , rwnd_bitmap is set to N _rwd bits. After the local end receives the information frame sent by the peer end, if the information frame is out of sequence and the sending sequence number N(S) is within the range of the receiving sliding window, it will be temporarily stored in the receiving sliding window. If the nth bit of rwnd_bitmap If there is an information frame in the nth position of the receiving sliding window corresponding to the bit, set the bit of rwnd_bitmap to 1, otherwise set it to 0. rcv_bitmap is used to save the bitmap carried in the received RR frame or REJ frame. The initial value of all bits in rcv_bitmap is all 1, so as to avoid erroneous retransmission before receiving RR frame and REJ frame.

For the local transmission device, if the received information frames arrive sequentially, the received information frames will be forwarded to the upper application immediately. At this time, the receiving sliding window is empty, and all bits of the corresponding rwnd_bitmap bits are all 0. If the information frame is lost during transmission and the received information frames are discontinuous, the out-of-sequence information frames will be temporarily stored in the receiving sliding window. At this time, the position of the information frame temporarily stored in the receiving sliding window corresponds to rwnd_bitmap The bit will be set to 1. When the local receives the information frame and sends an RR frame or REJ frame to the peer for confirmation, copy the local rwnd_bitmap to the bitmap field behind the RR frame or the REJ frame, so as to inform the peer of the local reception situation. If the effective bit length of rwnd_bitmap is not an integer multiple of 8, then pad with 0 to ensure that the bit length of the bitmap field is an integer multiple of 8. Since the effective bit length of the bitmap is determined by the size of the receiving sliding window, the peer end can determine the number of effective bits of the bitmap field carried in the RR and REJ frames according to the receiving sliding window size N _rwd negotiated between the two ends.

For the transmission device at the opposite end, when receiving the RR frame, according to the protocol, if the N(R) field in the received RR frame is greater than or equal to the confirmation variable V(A) of the local end and less than or equal to the sending state variable of the local end V(S), then N(R) in the RR frame is valid, update the confirmation variable V(A) of the local end to N(R), and save the bitmap field carried in the RR frame to the rcv_bitmap of the local end; otherwise The RR frame is discarded.

When receiving a REJ frame, according to the protocol, if the N(R) field in the received REJ frame is greater than or equal to the confirmation variable V(A) of the local end and is less than or equal to the sending state variable V(S) of the local end, the REJ frame N(R) in is valid, update the confirmation variable V(A) of the local end to N(R), and save the bitmap field carried in the REJ frame to the rcv_bitmap of the local end; otherwise, discard the REJ frame.

If the transmission device receives the RR frame, after the retransmission timer of the local end expires, if the confirmation variable V(A) of the local end is smaller than the sending state variable V(S), it needs to retransmit the information frame, and first resend according to the protocol The sequence number N(S)=V(A) information frame, and then judge the sending sequence number N(S) according to the bits of rcv_bitmap as V(A)+1 to V(A)+n(1≤n≤N _rwd , whether the information frame of V(A)+n<V(S)) needs to be retransmitted; if the nth bit is 0, and the sending sequence number corresponding to this bit is N(S)=V(A)+ If the difference between the last sending time of the information frame of n and the current time exceeds Td, the information frame will be retransmitted immediately.

If the transmission device receives the REJ frame, it needs to retransmit the information frame immediately. First, resend the information frame whose sequence number is N(S)=V(A) according to the protocol, and then the transmission device determines which information frames need to be retransmitted through V(A) and rcv_bitmap, the nth (1≤n≤ N _rwd ) bits are used to identify whether the information frame sent by the local end with the transmission sequence number N(S) is V(A)+n(V(A)+n<V(S)) is received by the peer end, if the If the bit is 1, it means that the opposite end of the information frame of N(S)=V(S)+n has received it. If the bit is 0, it means that the opposite end of the information frame of N(S)=V(S)+n has not yet Received, it may be necessary to resend the information frame whose sequence number is N(S)=V(A)+n. At this time, it is also necessary to calculate the latest sending time and current time of the information frame of N(S)=V(A)+n If the time difference exceeds the preset time T _d (the size of T _d is determined according to the transmission delay of the actual link), the information frame will be retransmitted immediately.

If the transmission device receives an information frame or an RNR frame, since the information frame and the RNR frame do not carry a bitmap, if the value of N(R) in the information frame or the RNR frame is greater than the confirmation variable V(A) of the local end, it means that there is a In the information frame sent by the end, a new information frame is received and confirmed by the opposite end, and V(A) needs to be updated to N(R); and the receiving sliding window of the opposite end has changed, so the previously saved rcv_bitmap can no longer correctly represent the The terminal receives the state of the sliding window. In order to avoid erroneous retransmission, it is necessary to set all valid bits of rcv_bitmap to 1, assuming that the peer end of the information frame with the sending sequence number greater than V(A) is not lost. Update the rcv_bitmap of the local end when the RR frame or REJ frame is received next time.

Assuming that the transmission devices at both ends of the LAPD link are the transmission device A and the transmission device B, the process of retransmitting the information frame will be described below.

As shown in Figure 7, the process of updating and sending rwnd_bitmap by transmission device A is described, and the specific steps are as follows:

Step 701: The transmission device A receives the information frame;

Transmission device A receives the information frame, and judges whether the current information frame is an out-of-sequence information frame, and if so, temporarily stores it in the receiving sliding window; If there are information frames in the receiving sliding window and the currently received information frames are continuous data frames, if there are, these data frames will be forwarded to the application layer, and the sliding window positions occupied by these information frames will be released; if not, the current The information frame is forwarded to the application layer;

Step 702: transmission device A updates rwnd_bitmap;

If there is an information frame temporarily stored in the nth (1≤n≤N _rwd ) position of the receiving sliding window, the nth bit of rcv_bimap is set to 1, otherwise it is set to 0;

Step 703: The transmission device A sends the RR frame or the REJ frame to the transmission device B.

Transmission device A copies the rwnd_bitmap to the bitmap field at the back of the RR frame or REJ frame. Since the number of valid bits in the rwnd_bitmap is not necessarily an integer multiple of 8, it is necessary to add 0 after the valid bits in the rwnd_bitmap to ensure the correctness of the bitmap field. The bit length is an integer multiple of 8.

As shown in Figure 8, it describes the processing flow of the transmission device B after receiving the data, and the specific steps are as follows:

Step 801: after the transmission device B receives the data, judge the type of the data frame, if it is an RR frame, go to step 802; if it is a REJ frame, go to step 804; if it is an information frame or an RNR frame, go to step 810;

Step 802: judging whether the RR frame is a legal data frame, that is, judging whether the N(R) field in the RR frame satisfies V(A)≤N(R)≤V(S), if not satisfied, then end; if satisfied, Go to step 803.

Step 803: The transmission device B updates the value of V(A), sets V(A)=N(R), copies the bitmap field in the RR to the rcv_bitmap variable at the local end, and ends the process.

The transmission device B may resend the information frame to the transmission device A according to the local confirmation variable V(A) and rcv_bitmap variable after its own retransmission timer expires.

Step 804: If it is a REJ frame, first judge whether N(R) is valid, that is, whether the N(R) field satisfies V(A)≤N(R)≤V(S), if not satisfied, it is invalid, and the process ends; Turn to step 805;

Step 805: Transmission device B resends the information frame with sequence number N(S)=N(R), and updates the value of V(A), sets V(A)=N(R), and copies the bitmap field in the REJ frame to the rcv_bitmap variable at the local end; the transmission device B uses a variable n to indicate the number of bits in the currently analyzed rcv_bitmap, and the initial value of n is 1, and then executes step 806;

Step 806: Determine whether the two conditions of 1≤n≤N _rwd and V(A)+n<V(S) are satisfied at the same time. If the transmission sequence number of the information frame represented by the nth bit of the description rcv_bitmap is satisfied, then step 807 is executed; otherwise, it ends;

Step 807: Check whether the nth bit of rcv_bitmap is 0, if it is 0, it means that the peer A has not received the information frame with the transmission sequence number N(S)=V(A)+n, and then judge the transmission sequence number N (S)=V(A)+n Whether the difference between the time of the latest transmission of the information frame of V(A)+n and the current time is greater than T _d , if greater, then perform step 808, otherwise perform step 809; if the nth bit of rcv_bitmap is 1 , indicating that the peer A has received the information frame with the transmission sequence number N(S)=N(R)+n, and does not need to retransmit, and executes step 809;

Step 808: Retransmit the information frame of N(S)=V(A)+n;

Step 809: Add 1 to the value of n, and then go to step 806.

Step 810: If what is received is an RNR frame or an I frame, first judge whether it is a legal data frame, that is, judge whether the N(R) field in the frame satisfies V(A)≤N(R)≤V(S) , if not satisfied, the N(R) value is invalid, then end; if satisfied, continue to judge whether N(R) satisfies N(R)>V(A), if satisfied, execute 811; if not satisfied, it means that there is no new If the I frame is received and acknowledged, it ends.

Step 811: N(R)>V(A), indicating that among the I frames sent by B, there is a new I frame received and confirmed by A, and the value stored in rcv_bitmap can no longer reflect the situation in A's receiving sliding window, so in order to avoid When wrong retransmission occurs, set all valid bits in rcv_bitmap to 1, update the value of V(A), set V(A)=N(R), and end the process.

As shown in Figure 9, it is the processing flow of the transmission device B after the retransmission timer of the transmission device B expires:

Step 901: The transmission device B retransmits the information frame with the transmission sequence number N(S)=V(A), and uses a variable n to indicate the number of bits in the currently analyzed rcv_bitmap. The initial value of n is 1, continue Execute 902;

Step 902: Determine whether the two conditions of 1≤n≤N _rwd and V(A)+n<V(S) are satisfied at the same time. If it is satisfied that the sending sequence number of the information frame represented by the nth bit of the rcv_bitmap is valid, then execute 903; otherwise, end;

Step 903: check whether the nth bit of rcv_bitmap is 0, if it is 0, it means that the peer A has not received the information frame with the transmission sequence number N(S)=V(A)+n, and then judge the transmission sequence number N (S)=V(A)+n Whether the difference between the time of the latest transmission of the information frame of V(A)+n and the current time is greater than T _d , if greater, then perform step 904, otherwise perform step 905; if the nth bit of rcv_bitmap is 1 , indicating that the opposite end A has received the information frame with the transmission sequence number N(S)=N(R)+n, and no retransmission is required, and step 905 is performed;

Step 904: retransmit the information frame of N(S)=V(A)+n, and execute step 905;

Step 905: Add 1 to the value of n, and continue to execute step 902.

In the embodiment of the present invention, the transmission device sets the first bitmap variable stored by itself according to the received information frame, and adds the first bitmap variable to the confirmation frame or veto frame and sends it to the peer end to inform the peer end of the local reception situation. The transmission device at the opposite end can resend the information frame whose transmission failed according to the received confirmation frame or veto frame. In the present invention, when the sender loses more than 2 frames of information, especially when the sending sequence numbers of the lost frames are discontinuous, the receiver can inform the sender what information has been lost through a confirmation frame or a veto frame. Frames do not need to be confirmed by both parties for multiple retransmission interactions, but can complete the retransmission of all lost information frames through one retransmission interaction, thereby improving the efficiency of retransmission.

The method embodiment corresponds to the device embodiment. For the part not described in detail in the method embodiment, refer to the description of the relevant part in the device embodiment. For the part not described in detail in the device embodiment, refer to the method The description of the relevant part in the embodiment is enough.

Those of ordinary skill in the art can understand that all or part of the steps in the method of the above-mentioned embodiments can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium. During execution, including the steps of the above-mentioned method embodiment, described storage medium, such as: magnetic disk, optical disc, read-only memory (Read-Only Memory, ROM) or random access memory (Random Access Memory, RAM) wait.

In each method embodiment of the present invention, the sequence number of each step can not be used to limit the order of each step. For those of ordinary skill in the art, the order of each step can be changed without paying creative work. Also within the protection scope of the present invention.

The above description is a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications can also be made. It should be regarded as the protection scope of the present invention.

Claims (14)

1. a D passage uplink access regulation transmission method is characterized in that, comprising:

Transmitting device receives the information frame that send the opposite end;

Said transmitting device upgrades first variable of self storing according to the information frame that receives, and said first variable is indicated the reception condition of said transmitting device to said information frame;

Said transmitting device adds first variable after upgrading in acknowledgement frame or the rejection frame to, and said acknowledgement frame or rejection frame are sent to the opposite end, so that the opposite end can resend the information frame that said transmitting device does not receive.

2. D passage uplink access regulation transmission method according to claim 1 is characterized in that said first variable is first bitmap variable, and said transmitting device upgrades first variable of self storing according to the information frame that receives and comprises:

The out-of-sequence information frame that said transmitting device will receive is temporarily stored in the sliding window of reception of self, n position in the sliding window of the corresponding said reception of n bit in said first bitmap variable;

If n position inner information frame in the sliding window of said reception; Then said transmitting device is made as 1 with n bit in first bitmap variable; If do not have information frame in n the position in the sliding window of said reception, then said transmitting device is made as 0 with n bit in first bitmap variable.

3. a D passage uplink access regulation transmission method is characterized in that, comprising:

Transmitting device receives acknowledgement frame or the rejection frame that sends the opposite end, and said acknowledgement frame or rejection frame indication opposite end are to the reception condition of information frame;

If said acknowledgement frame or veto the send state variable V (S) that N (R) field in the frame is not less than the affirmation variable V (A) of said transmitting device local terminal and is not more than said transmitting device local terminal; Then said transmitting device is updated to N (R) with the affirmation variable V (A) of local terminal, and upgrades second variable of self storing according to the bit map field that the said acknowledgement frame that receives is perhaps vetoed in the frame;

Said transmitting device confirms that according to the local terminal after upgrading the variable V (A) and second variable resend the information frame that the opposite end does not receive.

4. D passage uplink access regulation transmission method according to claim 3 is characterized in that said method also comprises:

Said transmitting device receives information frame or the RNR frame that send the opposite end;

If the value of the N (R) in said information frame or the RNR frame greater than the affirmation variable V (A) of local terminal, said local terminal is confirmed that variable V (A) is updated to N (R), and all effective bits of said second variable is set to 1.

5. D passage uplink access regulation transmission method according to claim 3 is characterized in that, said transmitting device confirms that according to the local terminal after upgrading the variable V (A) and second variable resend the information frame that the opposite end do not receive and comprise:

Said transmitting device is confirmed the information frame that the opposite end does not receive according to the said local terminal affirmation variable V (A) and second variable;

Said transmitting device pre-conditioned satisfy after, resend the information frame that the opposite end does not receive.

6. D passage uplink access regulation transmission method according to claim 5; It is characterized in that; Said second variable is second bitmap variable, and said transmitting device confirms that according to the said local terminal affirmation variable V (A) and second variable information frame that the opposite end does not receive comprises:

Said transmitting device judges whether the bit in said second bitmap variable is 0, and wherein, the corresponding said transmitting device of n bit in said second bitmap variable sends to transmitting Sequence Number of opposite end and is the information frame of N (S)=V (A)+n;

If n bit in said second bitmap variable is 0, then said transmitting device judgement opposite end does not receive the said transmitting device last time and sends to transmitting Sequence Number of opposite end and be the information frame of N (S)=V (A)+n.

7. D passage uplink access regulation transmission method according to claim 6 is characterized in that,

Said acknowledgement frame is the RR frame, and said rejection frame is the REJ frame, said transmitting device pre-conditioned satisfy after, resend the information frame that the opposite end do not receive and comprise:

If said transmitting device receives the REJ frame; Then said transmitting device is sending the said time difference into time of the information frame of N (S)=V (A)+n and current time of transmitting Sequence Number above behind the Preset Time, resends the said information frame into N (S)=V (A)+n of transmitting Sequence Number to the opposite end;

If said transmitting device receives the RR frame; Said transmitting device is after the retransmission timer of self is overtime; If send the said time difference into time of the information frame of N (S)=V (A)+n and current time of transmitting Sequence Number above Preset Time, then said transmitting device resends the said information frame into N (S)=V (A)+n of transmitting Sequence Number to the opposite end.

8. a transmitting device is characterized in that, comprising:

Receiver module is used to receive the information frame that send the opposite end;

Update module is used for upgrading first variable of self storing according to the information frame that receives, and said first variable is indicated the reception condition of said transmitting device to said information frame;

Sending module is used for adding first variable after upgrading to acknowledgement frame or rejection frame, and said acknowledgement frame or rejection frame is sent to the opposite end, so that the opposite end can resend the information frame that said transmitting device does not receive.

9. transmitting device according to claim 8 is characterized in that, said first variable is first bitmap variable, and said update module comprises:

Sub module stored is used for the out-of-sequence information frame that said receiver module receives is temporarily stored in the sliding window of reception, n position in the sliding window of the corresponding said reception of n bit in said first bitmap variable;

Submodule is set; Be used for if n position inner information frame of the sliding window of said reception; Then n bit in first bitmap variable is made as 1,, then n bit in first bitmap variable is made as 0 if do not have information frame in n the position in the sliding window of said reception.

10. a transmitting device is characterized in that, comprising:

Receiver module is used to receive the acknowledgement frame or the rejection frame that send the opposite end, and said acknowledgement frame or rejection frame indication opposite end are to the reception condition of information frame;

Update module; Perhaps veto the send state variable V (S) that N (R) field of frame is not less than the affirmation variable V (A) of said transmitting device local terminal and is not more than said transmitting device local terminal if be used for said acknowledgement frame; Then the affirmation variable V (A) with said transmitting device local terminal is updated to N (R), and upgrades second variable that said transmitting device is stored according to the bit map field that the said acknowledgement frame that receives is perhaps vetoed in the frame;

Sending module is used for confirming that according to the local terminal after upgrading the variable V (A) and second variable resend the information frame that the opposite end does not receive.

11. transmitting device according to claim 10 is characterized in that,

Said receiver module also is used to receive information frame or the RNR frame that send the opposite end;

If said update module also is used for the affirmation variable V (A) of N (R) value of said information frame or RNR frame greater than said transmitting device local terminal; Said local terminal is confirmed that variable V (A) is updated to N (R), and all effective bits of said second variable are set to 1.

12. transmitting device according to claim 10 is characterized in that, said sending module comprises:

Confirm submodule, be used for confirming the information frame that the opposite end does not receive according to the said local terminal affirmation variable V (A) and second variable;

Send submodule, be used for pre-conditioned satisfy after, resend the information frame that the opposite end does not receive.

13. transmitting device according to claim 12 is characterized in that, said second variable is second bitmap variable,

Said definite submodule is used for specifically judging whether the bit of said second bitmap variable is 0; Wherein, The corresponding said transmitting device last time of n bit in said second bitmap variable sends to transmitting Sequence Number of opposite end and is the information frame of N (S)=V (A)+n; If n bit in said second bitmap variable is 0, judge that then the opposite end does not receive the said transmitting device last time and sends to transmitting Sequence Number of opposite end and be the information frame of N (S)=V (A)+n.

14. transmitting device according to claim 13 is characterized in that, said acknowledgement frame is the RR frame, and said rejection frame is the REJ frame,

Said transmission submodule specifically is used for if said transmitting device receives the REJ frame; Then send the said time difference into time of the information frame of N (S)=V (A)+n and current time of transmitting Sequence Number above behind the Preset Time, resend the said information frame into N (S)=V (A)+n of transmitting Sequence Number to the opposite end at said transmitting device;

If said transmitting device receives the RR frame; After the retransmission timer of said transmitting device is overtime; If said transmitting device sends the said time difference into time of the information frame of N (S)=V (A)+n and current time of transmitting Sequence Number above Preset Time, then resend the said information frame into N (S)=V (A)+n of transmitting Sequence Number to the opposite end.

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