CN1330155C - Data processing method of protocol data unit in radio chain circuit control disordcred sequence transmission function - Google Patents

Abstract

The present invention discloses a data processing method for a protocol data unit (PDU) in an orderless transmission function controlled by a radio link, which comprises: when a new PDU is received and cached, whether a PDU connected with the current PDU is cached in a window is checked; if the PDU connected with the current PDU is cached in a window, data is processed according to the existing protocol; if the PDU connected with the current PDU is not cached in a window, data is processed according to strategies established in advance; when a window moves or a counter is overtime, and the PDU in the window is required to be deleted, data of the PDU containing integral SDU is processed according to strategies established in advance. The present invention can avoid the unnecessary loss or duplicate copy of SDU for the operation of single discontinuous PDU in a recombined cache in an orderless transmission function of MCCH.

Description

Protocol data unit data processing method in wireless link control out-of-sequence transmission function

technical field

The present invention relates to the radio link control (RLC, Radio Link Control) out-of-sequence delivery (OSD, Out of Sequence Delivery) technology in the mobile network multimedia multicast broadcasting service (MBMS, Multimedia Broadcast/Multicast Service), in particular to a kind of RLC The protocol data unit (PDU, Packet Data Unit) data processing method in the OSD function.

Background technique

Now, people's demand for mobile communication is no longer satisfied with telephone and messaging services. With the rapid development of the Internet (Internet), a large number of multimedia services have emerged, some of which require multiple users to receive the same data at the same time, such as video On-demand, TV broadcasting, video conferencing, online education, interactive games, etc. Compared with general data, these mobile multimedia services have the characteristics of large data volume, long duration, and delay sensitivity. The current IP multicast technology is only applicable to wired IP networks, but not to mobile networks, because mobile networks have specific network structures, functional entities and wireless interfaces, which are different from wired IP networks.

In order to effectively utilize mobile network resources, the Wideband Code Division Multiple Access (WCDMA)/Global System for Mobile Communications (GSM) global standardization organization proposed the Multimedia Multicast Broadcasting Service (MBMS, Multimedia Broadcast/ Multicast Service), a point-to-multipoint service that provides a data source to send data to multiple users in the mobile network, realizes network resource sharing, and improves the utilization rate of network resources, especially air interface resources. The MBMS defined by 3GPP can not only realize plain text and low-rate message multicast and broadcast, but also realize multicast and broadcast of high-speed multimedia services, which undoubtedly conforms to the trend of future mobile data development.

As shown in Figure 1, the process description of the OSD function in the current 3GPP TS25.322 protocol is roughly as follows:

Steps 11-13, when receiving a PDU from the MAC sublayer, first judge whether it is the first PDU received, if yes, initialize the state variable VR (UOH) to be the sequence number of this PDU minus 1 (SN-1 );

Step 14, generally the received PDU is not the first one, then judge whether the received PDU is within the window;

Steps 15-17, if the serial number of the received PDU is within the receiving window, that is, VR(UOH)≥SN>VR(UOH)-OSD_Window_Size, then judge whether there is a PDU with the same serial number that has been cached, and if so, delete the current PDU, otherwise, cache the current PDU;

Steps 18-23, if the serial number of the received PDU is outside the window, cache the PDU, update VR(UOH)=SN, and move the window accordingly, delete all PDUs with serial numbers outside the window, if the timer Timer_OSD starts , then stop the timer, restart the timer, update VR(UDR)=VR(UDH)-DAR_Window_Size+1.

For buffered PDUs, consider whether all consecutive PDUs have "length indication" to indicate a complete service data unit (SDU, Service Data Unit), if so, reassemble these PDUs into SDUs, and serve these RLC SDUs through no-acknowledgment mode The access point (UM-SAP) sends it to the upper layer, and deletes the PDU that has recovered the SDU, except for the PDU with a special length indication; if the timer Timer_OSD times out, delete all the cached PDUs.

The disadvantage of the existing technology is that it ignores the fact that the PDU contains a complete SDU. When a PDU containing a complete SDU is received separately, the receiving end will not consider directly recovering the SDU, but waits for the previous and subsequent PDUs. If the previous and subsequent PDUs are lost or If it cannot be received within a certain period of time, the SDU contained in this PDU cannot be recovered and will be deleted.

In addition, a PDU containing a complete SDU may also contain part of other SDUs, and these SDUs are incomplete. At this time, it is not clear whether such a complete SDU should be recovered, and it may cause repeated reassembly. If you restore the complete SDU just received when it is incomplete, you may restore the SDU again when receiving other parts of the SDU, resulting in completely unnecessary copies.

This situation may have a more obvious impact on the access information sent on the main control channel (MCCH), because out-of-sequence transmission is introduced as one of the functions applied on the MCCH by the sender for access information. The interruption problem caused the sequence numbers before and after the access information to be sent to be inconsistent. At the receiving end, the access information is separate and discontinuous when received, and the access information is often all SDUs in a single PDU. At this time, it is necessary to restore such access information in time.

Contents of the invention

In view of this, the purpose of the present invention is to provide a protocol data unit data processing method in the out-of-sequence transmission function of the radio link control, for the operation of independent discontinuous PDUs in the reorganization cache of the MCCH out-of-sequence transmission function, to avoid Unnecessary loss or duplication of SDUs.

Based on the above purpose, the protocol data unit PDU data processing method in the wireless link control out-of-sequence transmission function provided by the present invention includes:

a) When a new PDU is received and cached, check whether there is a PDU continuous with the current PDU in the window, if so, process it according to the existing protocol; otherwise, process the data according to the pre-established strategy ;

b) When the PDU in the window needs to be deleted due to window movement or counter timeout, perform data processing on the PDU containing the complete SDU according to the pre-established policy.

The process of processing data according to a pre-established strategy in step a) of the method includes:

a1) According to the length indication in the current PDU, it is judged whether the PDU contains at least one complete SDU alone, if yes, the data processing is performed on the PDU according to the pre-established strategy, and the return is to step a); otherwise, directly return to the step a) .

The method for data processing the PDU described in step a1) of the method is to directly cache the PDU, or firstly reassemble the PDU to recover the complete SDU, and then send it to the upper layer, and then delete the PDU.

The process of processing data according to the pre-established strategy in step a) of the method is: continue to cache the current PDU.

The data processing process in step b) of the method includes: checking whether the current PDU that needs to be deleted contains a complete SDU according to the length indication in the PDU, and if so, recombining and recovering the complete SDU from these PDUs and sending it Go to the upper layer and delete the PDUs that need to be deleted due to window movement or counter timeout; otherwise, directly delete the PDUs that need to be deleted due to window movement or counter timeout.

The data processing process in step b) of the method is: directly delete the PDUs that need to be deleted due to window movement or counter overtime.

The data processing process in step b) of the method is: according to the length indication in the current PDU, it is judged whether the PDU contains at least one complete SDU alone, and if so, data processing is performed on the PDU according to a pre-established strategy; otherwise, Delete PDUs that need to be deleted due to window movement or counter timeout.

In the step a1) of the method, if the current PDU contains at least one complete SDU and other SDU parts, the complete SDU in the current PDU is reassembled, cached, and sent to the upper layer after waiting for a preset period of time. The current PDU Continue caching and return to step a); otherwise, directly return to step a);

The data processing process in step b) is: directly delete the PDUs that need to be deleted due to window movement or counter timeout.

In the step a1) of the method, if the current PDU contains at least one complete SDU and other SDU partial content, then the complete SDU in the current PDU is reassembled and sent to the upper layer, and the SDU is marked in the cache. Then send the SDU to the upper layer, the current PDU continues to be buffered, and returns to step a);

The data processing process in step b) is: directly delete the PDUs that need to be deleted due to window movement or counter timeout.

The mark added in the cache in the method at least includes the sequence number of the recovered SDU.

In the step a1) of the method, if the current PDU contains at least one complete SDU and other SDU partial contents, the complete SDU in the current PDU is reassembled and deleted, and the upper layer is notified which SDU is deleted, and the current PDU continues to be cached Return to step a);

The data processing process in step b) is: directly delete the PDUs that need to be deleted due to window movement or counter timeout.

As can be seen from the above, when a PDU data processing method in the wireless link control out-of-sequence transmission function of the present invention receives a new PDU and does not find a continuous PDU with it, further according to the PDU in the current PDU The length indication distinguishes the situation of a PDU containing a complete SDU alone, and a PDU containing a complete SDU and other SDU parts, and performs data processing according to a pre-specified strategy, thereby avoiding the loss of useful information and avoiding Duplicate problems that may arise during processing.

Description of drawings

FIG. 1 is a schematic flow chart of a protocol data unit data processing method in the existing 3GPP TS25.322 protocol wireless link control out-of-sequence transmission function;

Fig. 2 is a schematic flow chart of a preferred embodiment 1 of the present invention;

Fig. 3 is a schematic flow diagram of the second preferred embodiment of the present invention;

Fig. 4 is a schematic flow diagram of a third preferred embodiment of the present invention;

Fig. 5 is a schematic flow chart of the fourth preferred embodiment of the present invention;

Fig. 6 is a schematic flow chart of the fifth preferred embodiment of the present invention.

Detailed ways

The core idea of the protocol data unit PDU data processing method in the wireless link control out-of-sequence transmission function of the present invention includes: after a new PDU is received and cached, check whether there is a PDU continuous with the current PDU cached in the window , if there is, process it according to the existing protocol; otherwise, continue to cache and wait for the next PDU to be received; when the window moves or the counter times out and the PDU in the window needs to be deleted, the PDU containing the complete SDU is processed according to the pre-established strategy Perform data processing.

The method of the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Embodiment one:

Step 101, the MAC sublayer performs PDU reception. After a new PDU is received and cached, check whether there is a PDU continuous with the current PDU in the window, and if so, process it according to the existing protocol, that is, to The PDU that constitutes the complete SDU is reassembled and the SDU is sent to the upper layer; otherwise, go to step 102 .

Step 102: According to the length indication in the current PDU, it is judged whether the PDU contains at least one complete SDU alone. If yes, the SDU is reassembled and sent to the upper layer, and the current PDU is deleted; otherwise, continue to cache the PDU.

Step 103, when the PDU in the cache is moved out of the window due to window movement or the PDU in the window needs to be deleted due to the timer Timer_OSD timeout, check whether each PDU currently to be deleted contains a complete SDU according to the length indication in the PDU , if there is, the complete SDU is reassembled from these PDUs and sent to the upper layer, and the PDU that needs to be deleted due to window movement or counter timeout is deleted; otherwise, the PDU that needs to be deleted due to window movement or counter timeout is directly deleted .

Usually, the PDUs containing complete SDUs detected in step 103 are those cases containing at least one complete SDU and part of other SDUs, so this step can restore the complete SDU contained in the PDU in this case Come out and send to the upper floor.

In this embodiment, the process of step 102 can also be omitted, so that the situation that the PDU contains at least one complete SDU alone and the situation that contains at least one complete SDU and other SDU parts can be processed together in step 103 In this way, if there is no continuous PDU buffered with the current PDU in the matching step 101 in the window, the PDU will continue to be buffered.

Embodiment two:

Step 201, the MAC sublayer performs PDU reception. When a new PDU is received and cached, check whether there is a PDU continuous with the current PDU in the window. If so, process it according to the existing protocol; otherwise, enter Step 202.

Step 202: According to the length indication in the current PDU, it is judged whether the PDU contains at least one complete SDU alone. If yes, the SDU is reassembled and sent to the upper layer, and the current PDU is deleted; otherwise, continue to buffer the PDU.

Step 203 , when the PDUs in the buffer are moved out of the window due to window movement or the PDUs in the window need to be deleted due to the timeout of the counter Timer_OSD, directly delete the PDUs to be deleted.

It can be seen that the difference between this embodiment and Embodiment 1 is that, for the situation that includes at least one complete SDU and other SDU partial contents, this embodiment directly deletes them without restoring them.

In addition, in this embodiment, the process of step 202 can also be placed in step 203 and then executed when the PDU in the window needs to be deleted, that is, judge whether the PDU contains at least one complete SDU alone according to the length indication in the current PDU, If yes, then perform data processing on the PDU according to a pre-established strategy; otherwise, delete the PDU cached in the current window; or the process of step 202 can also be omitted, so no matter for the PDU that contains at least one complete SDU separately The case, or the case containing at least one complete SDU and part of other SDUs will be deleted together in step 203 . In step 201 that cooperates with these two schemes, if there is no PDU that is continuous with the current PDU in the window, continue to cache the PDU.

Embodiment three:

Step 301, the MAC sublayer performs PDU reception. When a new PDU is received and cached, check whether there is a PDU continuous with the current PDU in the window. If so, process it according to the existing protocol; otherwise, enter Step 302.

Step 302, judge whether the PDU contains a complete SDU according to the length indication in the current PDU, if it contains a single SDU, recombine and recover the SDU and send it to the upper layer, and delete the current PDU; if it contains at least one complete SDU SDU and other SDU partial content, then enter step 303; if not contain complete SDU, continue to cache this PDU.

Wherein, the judging process described in this step can be implemented in two steps, that is, first judge whether the current PDU contains a complete SDU alone, if not, then further judge whether the current PDU contains at least one complete SDU and other SDU parts.

Step 303: Reassemble and restore the complete SDUs in the current PDU, cache them, wait for a preset period of time, and then send them to the upper layer, continue to cache the current PDU, wait for the rest of the other SDUs described in the current PDU to be restored together.

Wherein, the preset period of waiting should be less than the time between window removal and counter Timer_OSD timeout, for example: if the time for window removal is about 64 TTIs, then the preset period of time can be set to 16TTIs.

Step 304, when the PDUs in the buffer are moved out of the window due to window movement or the PDUs in the window need to be deleted due to the timer Timer_OSD timeout, directly delete these PDUs that need to be deleted.

Embodiment four:

Step 401, the MAC sublayer performs PDU reception. When a new PDU is received and cached, check whether there is a PDU continuous with the current PDU in the window. If so, process it according to the existing protocol; otherwise, enter Step 402.

Step 402, judge whether the PDU contains a complete SDU according to the length indication in the current PDU, if it contains a single SDU, recombine and recover the SDU and send it to the upper layer, and delete the current PDU; if it contains at least one complete SDU SDU and other SDU partial content, then enter step 403; if the complete SDU is not included, continue to cache the PDU.

Step 403, reassemble and restore the complete SDU in the current PDU, and then send it to the upper layer, mark it in the buffer to identify that the SDU has been restored and send it to the upper layer, continue to buffer the current PDU, and wait for other SDUs mentioned in the current PDU to be received After the rest of the SDUs are reassembled and restored together, the other SDUs except for the marking are sent to the upper layer.

Wherein, the marking may be saving the sequence number of the SDU in the cache. Of course, those skilled in the art can easily think of marking in other ways, as long as the restored SDU is marked, so as to avoid the problem of repeated reassembly.

Step 404, when the PDUs in the buffer are moved out of the window due to window movement or the PDUs in the window need to be deleted because the counter Timer_OSD times out, directly delete these PDUs that need to be deleted.

Embodiment five:

Step 501, the MAC sublayer performs PDU reception. When a new PDU is received and cached, check whether there is a PDU continuous with the current PDU in the window. If so, process it according to the existing protocol; otherwise, enter Step 502.

Step 502, judge whether the PDU contains a complete SDU according to the length indication in the current PDU, if it contains a single SDU, reassemble and recover the SDU and send it to the upper layer, and delete the current PDU; if it contains at least one complete SDU SDU and other SDU parts, then enter step 503; if the complete SDU is not included, continue to cache the PDU.

Step 503, reassemble and restore the complete SDU in the current PDU, then delete it, notify the upper layer which SDU is deleted, continue to cache the current PDU, wait for the rest of the other SDUs described in the current PDU to be reassembled and restored together, And sent to the upper layer.

The notification may be sending the PDU sequence number+SDU bits of the currently deleted SDU to the upper layer to indicate the currently deleted SDU. Of course, those skilled in the art can easily think of other ways to notify the upper layer. In this way, the upper layer can know which SDU has performed the recovery operation, so as to avoid the problem of repeated reassembly.

Step 504, when the PDUs in the cache are moved out of the window due to window movement or the PDUs in the window need to be deleted due to the timer Timer_OSD timeout, directly delete these PDUs that need to be deleted.

In the above embodiments, for the case where a PDU contains only one SDU, a policy of directly deleting the current PDU without recovery may also be adopted.

Claims (5)

1. A Protocol Data Unit (PDU) data processing method in a radio link control out-of-order transmission function is characterized by comprising the following steps:

a) when a new PDU is received and buffered, checking whether a PDU which is continuous with the current PDU is buffered in the window, if so, recombining the PDUs which can form a complete SDU to recover the SDU and sending the SDU to an upper layer;

if not, caching the current PDU, or judging whether the current PDU contains at least one complete SDU according to the length indication in the current PDU, if so, recombining and recovering the complete SDU and then sending to an upper layer and deleting the current PDU, otherwise, caching the current PDU;

b) when the PDU in the window needs to be deleted due to window movement or overtime of a counter, the PDU needing to be deleted is directly deleted; or,

and judging whether the PDU needing to be deleted contains at least one complete SDU or not according to the length indication in the PDU, if so, recombining and recovering the complete SDU, then sending the complete SDU to an upper layer and deleting the PDU needing to be deleted, and if not, directly deleting the PDU needing to be deleted.

2. The method according to claim 1, wherein said step a), after determining that said PDU contains at least one complete SDU, before resuming said complete SDU after reassembly and sending to an upper layer and deleting said current PDU, further comprises:

judging whether the PDU contains at least one complete SDU according to the length indication in the current PDU, if so, recombining and recovering the complete SDU, then sending the complete SDU to an upper layer, and deleting the current PDU;

if the current PDU does not contain the SDU and the other SDU, judging whether the current PDU contains at least one complete SDU and other SDU partial contents or not according to the length indication in the current PDU, if so, recombining and recovering the complete SDU in the current PDU, caching, sending to an upper layer after waiting for a preset time, continuing caching the current PDU, recovering the current PDU and sending to the upper layer after waiting for receiving the rest parts of the other SDU in the current PDU, and if not, caching the PDU;

and, in the step b), when the window movement or the counter overtime occurs and the PDU in the window needs to be deleted, the PDU which needs to be deleted due to the window movement or the counter overtime is directly deleted.

3. The method of claim 2, wherein when it is determined that the current PDU contains at least one complete SDU and partial contents of other SDUs, the buffering the reassembled and recovered SDU further comprises: mark in the buffer that the SDU has been recovered.

4. The method of claim 3, wherein the mark in the buffer at least comprises a sequence number of the recovered SDU.

5. The method according to claim 1, wherein said step a), after determining that said PDU contains at least one complete SDU, before resuming said complete SDU after reassembly and sending to an upper layer and deleting the current PDU, further comprises:

judging whether the PDU contains a complete SDU according to the length indication in the current PDU, if so, recombining and recovering the complete SDU, then sending to an upper layer and deleting the current PDU;

if the current PDU does not contain the SDU and the other SDU, judging whether the current PDU contains at least one complete SDU and other SDU partial contents or not further according to the length indication in the current PDU, if so, deleting the complete SDU in the current PDU after recombination and recovery, informing an upper layer of which the deleted SDU is, continuing caching the current PDU, recovering the current PDU and sending the PDU to the upper layer after waiting for receiving the rest parts of the other SDUs in the current PDU, and if not, caching the PDU;

and, in the step b), when the window movement or the counter overtime occurs and the PDU in the window needs to be deleted, the PDU which needs to be deleted due to the window movement or the counter overtime is directly deleted.

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