CN101677266B

CN101677266B - Method, system and apparatus for the operation of reordering and repeated elimination

Info

Publication number: CN101677266B
Application number: CN2008102228303A
Authority: CN
Inventors: 赵毅; 李国庆; 刘佳敏
Original assignee: China Academy of Telecommunications Technology CATT
Current assignee: China Academy of Telecommunications Technology CATT; Datang Mobile Communications Equipment Co Ltd
Priority date: 2008-09-19
Filing date: 2008-09-19
Publication date: 2012-12-26
Anticipated expiration: 2028-09-19
Also published as: CN101677266A

Abstract

The invention provides a method for controlling the operation of reordering and repeated elimination, includes the following steps: a receiving end receiving the sequence number SN of the upper boundary after receiving, wherein, the upper boundary SN is the upper boundary of SN of Packet Data Convergence Protocol Service Data Unit PDCP SDU where disorder may occur; the receiving end determining the termination time of the operation of reordering and repeated elimination based on the received upper boundary SN. By the transmission of the upper boundary SN, the receiving end determines the termination time of the operations of reordering and repeated elimination based on the upper boundary SN, so that the Flush-timer timer in the prior art is not needed, thereby avoiding the technology defect caused by inaccurate timing length setting of the Flush-timer timer.

Description

Control is reordered and repeated elimination method of operating, system and device

Technical field

The present invention relates to communication technical field, particularly a kind of control is reordered and repeated elimination method of operating, system and device.

Background technology

In order to ensure in the longer time, keeping higher competitiveness, 3GPP (Third GenerationPartnership Project, third generation gpp) has started LTE (LongTerm Evolution, the Long Term Evolution) research project of 3G wireless interface technology.

In the LTE system, the data forwarding between eNB in the handoff procedure (evolution base station) is mainly accomplished by PDCP (Packet Data Converge Protocol, data convergence agreement) layer.When non-switching; RLC (Radio Link Control; Radio Link control) (forming RLC SDU) upwards is submitted to receiving entity PDCP layer according to the order of sequence after the AM receiving entity data processing that will receive from sending entity; For down link, above-mentioned receiving entity is that UE (subscriber equipment), sending entity are eNB; And above-mentioned receiving entity is eNB for up link, and sending entity is UE.Because when switching, rlc layer can not provide data delivery according to the order of sequence to the PDCP layer, so out of order situation can appear in the PDCP PDU (ProtocolData Unit, protocol Data Unit) that the PDCP layer receives.Because the PDCP layer will guarantee to submit PDCP SDU (Service Data Unit according to the order of sequence to the upper strata; Service data unit); Therefore when switching, the PDCP SDU that the PDCP layer will be handled back formation to the PDCP PDU that submits from lower floor reorders and the repeated elimination operation.

Mainly solve the control problem that reorders and repeated elimination is operated in the prior art through the Flush_timer timer.When switching takes place, start the Flush_timer timer, adopt the reordering windowing mechanism, only the PDCP SDU that is positioned at the reordering window is done and reorder and the repeated elimination operation at receiving terminal (following behavior UE, last behavior target eNB).Said receiving terminal is judged the corresponding PDCP SDU of data that receives; If being positioned at the reordering window, this PDCP SDU reorders and the repeated elimination operation; Otherwise abandon this PDCP SDU; Like this as long as reordering window long enough, just can guarantee that the PDCP layer submits the completion of operation according to the order of sequence.

Flush_timer is used to control to the termination time that out of order PDCP SDU reorders and repeated elimination is operated possibly take place; But the rational time span of Flush_timer timer is set is very difficult, and its time length can receive influence of various factors.For example for down link; At first, how long UE does not know that target eNB resends, and out of order SDU possibly take place has, in addition; Not only before target eNB, to change the time that is spent through the X2/S1 interface relevant with source eNB data for the Flush_timer time span; But also receive that the very big of channel condition influences in the receiving course, because the time that RLC and MAC (Media Access Control, medium access control) layer successfully receive packet under different channel conditions has very big difference.For up link; How long target eNB does not know that UE resends yet, and out of order SDU possibly take place has, and the Flush_timer duration mainly receives RLC and MAC layer under the different channel conditions successfully to receive the influence of the time of packet in the current scheme that adopts.Therefore can find out that how the rational time span of Flush_timer timer is set is very difficult,, unnecessary reordering and the repeated elimination operation then will occur, increase the amount of calculation of receiving terminal if the time span value is long; If value is too short, then can not guarantee submitting according to the order of sequence of PDCP course upper layer data.Therefore the shortcoming of prior art is existingly can't satisfy the needs that operation control effectively with repeated elimination that reorder when switching through the Flush_timer timer.

Summary of the invention

The object of the invention is intended to solve at least one of above-mentioned technological deficiency, particularly solves when reordering with the repeated elimination operation through the control of Flush_timer timer in the prior art, owing to the inaccurate amount of calculation that increases of value or the out of order problem of generation.

For achieving the above object; The present invention one side proposes a kind of control and reorders and the repeated elimination method of operating; May further comprise the steps: receiving terminal (following behavior UE; Last behavior target eNB) after switching, receive coboundary sequence number SN, said coboundary SN is the coboundary that the SN of out of order data convergence protocol service data cell PDCP SDU possibly take place; Said receiving terminal is confirmed the termination time of permutatation and repeated elimination operation according to the said coboundary SN that receives.

As an embodiment of said method of the present invention, said receiving terminal is a user equipment (UE), and said UE receives coboundary SN and is specially after switching: the source evolution base station eNB sends to target eNB with said coboundary SN through the X2/S1 interface; Said target eNB is when said UE sends data, and the PDCP PDU that said coboundary SN is corresponding sends to said UE as first PDCP PDU.

As an embodiment of said method of the present invention, said receiving terminal is UE, and said UE receives coboundary SN and is specially after switching: said source eNB sends to target eNB with said coboundary SN through the X2/S1 interface; Said target eNB sends to UE through status report with said coboundary SN when said UE sends data.

An embodiment as said method of the present invention; Said receiving terminal is UE; Said UE is specially receiving coboundary SN after the switching: during to said target eNB forwarding data, be given to said target eNB before the PDCP SDU that said source eNB is corresponding with said coboundary SN is preferential through the X2/S1 interface at said source eNB; Said target eNB is sent as first PDCP PDU the corresponding PDCP PDU of said PDCP SDU that receives when said UE sends data to UE.

As an embodiment of said method of the present invention, said receiving terminal is UE, and said UE receives coboundary SN and is specially after switching: said source eNB sends to said UE through switching command message with said coboundary SN.

In the above-described embodiments, the RRC that said coboundary SN is source eNB is when sending switching command message, and the SN of the PDCP SDU that the new RLC PDU that RLC will send is corresponding subtracts 1.

An embodiment as said method of the present invention; Said receiving terminal is a target eNB; Said target eNB is specially at the said coboundary SN of reception after the switching: said UE is when said target eNB is sent data, and the PDCP PDU that coboundary SN is corresponding sends to target eNB as first PDCP PDU.

An embodiment as said method of the present invention; Said receiving terminal is a target eNB; Said target eNB is specially at the said coboundary SN of reception after the switching: said UE sends to said target eNB through status report with said coboundary SN when said target eNB is sent data.

As an embodiment of said method of the present invention, said receiving terminal is a target eNB, and said target eNB receives said coboundary SN and is specially after switching: said UE sends said coboundary SN through switch acknowledgment message to said target eNB.

In the above-described embodiments, the RRC that said coboundary SN is UE is when receiving switching command message, and the SN of the PDCP SDU that the new RLC PDU that RLC will send is corresponding subtracts 1.

An embodiment as said method of the present invention; Also comprise: startup reorder with repeated elimination operation after, start timer, lower boundary SN is upgraded in the overtime back of the timing of said timer; And the said timer of resetting, said timing preestablishes.

An embodiment as said method of the present invention also comprises: startup reorder with repeated elimination operation after, start timer, the timing of said timer is used to control the required time of next SDU that receives the corresponding PDCP SDU of lower boundary SN; Receive the next SDU of the corresponding PDCP SDU of lower boundary SN at said receiving terminal after, said receiving terminal is updated to the corresponding SN of said SDU of reception and the said timer of resetting with the lower boundary SN of record; When said timer expiry; And when not receiving the next SDU of the corresponding PDCP SDU of lower boundary SN; The more said lower boundary SN of new record is the corresponding SN of the previous PDCP SDU that has received of the next SDU gap that does not receive, the said timer of resetting, and continue to receive SDU.

In the above-described embodiments, also comprise: when the lower boundary SN of said receiving terminal record >=coboundary SN, stops said reorder and repeated elimination is operated.

The present invention also proposes a kind of control on the other hand and reorders and the repeated elimination operated system; Comprise UE, source eNB and target eNB; Said UE; Be used for when switching the coboundary SN of upstream data is sent to target eNB, and after switching the coboundary SN of downlink data receiving, and downlink data is reordered the termination time with the repeated elimination operation according to the coboundary SN control of the downlink data that receives; Said target eNB is used for the termination time that SN control in coboundary is reordered to upstream data and repeated elimination is operated according to the upstream data of said UE transmission; Said source eNB is used for after sending switching command the coboundary SN of downlink data is sent to said UE, or is transmitted to said UE through target eNB.

Further aspect of the present invention also proposes a kind of receiving terminal; Be used for reordering and the repeated elimination operation according to the coboundary SN control that receives; Comprise receiver module and control module; Said receiver module is used for after switching, receiving coboundary SN, and said coboundary SN is the coboundary that the SN of out of order PDCP SDU possibly take place; Said control module is used for confirming the termination time that permutatation and repeated elimination are operated according to the said coboundary SN that said receiver module receives.

As an embodiment of said method of the present invention, when said receiving terminal was UE, the RRC that said coboundary SN is source eNB was when sending switching command message, and the SN of the PDCP SDU that the new RLC PDU that RLC will send is corresponding subtracts 1.

As an embodiment of said method of the present invention, when said receiving terminal was target eNB, the RRC that said coboundary SN is UE was when receiving switching command message, and the SN of the PDCP SDU that the new RLC PDU that RLC will send is corresponding subtracts 1.

An embodiment as said method of the present invention also comprises time block, is used for upgrading lower boundary SN in the overtime back of timing, and the said timer of resetting, said timing preestablishes.

An embodiment as said method of the present invention; Also comprise time block, be used to control the required time of next SDU that receives the corresponding PDCP SDU of lower boundary SN, when said time block overtime; And when not receiving next SDU; The more said lower boundary SN of new record is the corresponding SN of the previous PDCP SDU that has received of the next SDU gap that does not receive, the said timer of resetting, and continue to receive SDU; And when the lower boundary SN >=coboundary SN of record, stop reordering and the repeated elimination operation.

The present invention also proposes a kind of eNB, comprises above-mentioned receiving terminal.

The present invention also proposes a kind of UE, comprises above-mentioned receiving terminal.

The present invention is through the transmission of coboundary SN; Make receiving terminal can confirm the termination time of permutatation and repeated elimination operation according to coboundary SN; Therefore need not Flush_timer timer of the prior art, thereby avoid the Flush_timer length of timer that inaccurate caused technological deficiency is set.And the timer that proposes through the present invention, and the method that the timer timing is set also can be avoided in handoff procedure because PDCP SDU is dropped caused deadlock effectively.

Aspect that the present invention adds and advantage part in the following description provide, and part will become obviously from the following description, or recognize through practice of the present invention.

Description of drawings

Above-mentioned and/or additional aspect of the present invention and advantage are from obviously with easily understanding becoming the description of embodiment below in conjunction with accompanying drawing, wherein:

Fig. 1 reorders and repeated elimination method of operating flow chart for control in the one embodiment of the invention down link;

Fig. 2 reorders and repeated elimination method of operating flow chart for control in the another embodiment of the present invention up link;

Fig. 3 reorders and repeated elimination operated system structure chart for another embodiment of the present invention control;

Fig. 4 is an another embodiment of the present invention receiving terminal structure chart.

Embodiment

Describe embodiments of the invention below in detail, the example of said embodiment is shown in the drawings, and wherein identical from start to finish or similar label is represented identical or similar elements or the element with identical or similar functions.Be exemplary through the embodiment that is described with reference to the drawings below, only be used to explain the present invention, and can not be interpreted as limitation of the present invention.

For down link and up link, it is also inequality that it produces out of order situation, below just the out of order reason of its generation etc. carried out brief account.

For down link:

In down link; For the DRB that is mapped to RLC AM (Data Radio Bearer; Data Radio Bearer); The main task that PDCP will accomplish in the handoff procedure is that source eNB gives target eNB with following three types of PDCP SDU through changeing (forwarding) before the X2/S1 interface, sends to UE by target eNB again.These three types of PDCP SDU are:

The first kind, source eNB send to UE, but are not confirmed the corresponding SDU of PDCPPDU that success receives by UE as yet, and wherein this partial data possibly successfully received by UE but not return state report as yet.

Second type, the rlc layer of source eNB is treated and handling, but the corresponding PDCP SDU of the data of not sending as yet.

Handling the untreated PDCP SDU of Buddhist monk in the 3rd type, PDCP layer.

When switching generation, the UE end starts the Flush_timer timer, opens and delivers according to the order of sequence and the repeated elimination function, and above-mentioned data are handled.It is to be noted; Cause the PDCP SDU that receives in the UE end PDCP layer handoff procedure take place out of order, need do at the PDCP layer and reorder and after the reason of repeated elimination operation is to receive the handover_command order; The out of order PDCP of the being submitted to layer of RLC SDU that the rlc layer of UE end can be assembled into, and source eNB can resend to UE through target eNB all data that do not receive confirmation.Source eNB through target eNB in the data that UE resends, a part is that UE does not receive the data that successfully need retransmit, another part is to be held successfully the data (although being out of order) that receive by UE.When UE receives first's data, need do (reordering) operation of reordering with already present out of order PDCP SDU in the PDCP buffering; Need do the repeated elimination operation with the out of order PDCP SDU that exists in the PDCP buffering when receiving the second portion data.

Can find out through above analysis,, need do and reorder and the corresponding PDCP SDU of the data of repeated elimination operation is the first kind PDCP SDU that the source eNB that receives of UE is given to target eNB before through the X2/S1 interface for the UE of down link.

For up link:

In the up link, for the DRB that is mapped to RLC AM, the main task that PDCP will accomplish in the handoff procedure is that UE does head compression (if configuration) again with following three types of SDU and send to target eNB the encryption back:

The first kind, UE send to source eNB, but are not confirmed the corresponding SDU (partial data possibly successfully received by source eNB but not return state report as yet) of PDCP PDU that success receives by source eNB as yet.

Second type, the rlc layer of UE is treated and handling, but the corresponding PDCP SDU of the data of not sending as yet.

The PDCP SDU that is handling in the 3rd type, the PDCP layer of UE.

Similar with down link; Doing the reason that reorders with the repeated elimination operation at the PDCP layer is: when switching; Source eNB can be given to target eNB before with the out of order PDCP SDU that receives through the X2/S1 interface, can resend to target eNB all data that do not receive source eNB confirmation and switch back UE.In the data that target eNB resends, a part is to switch preceding source eNB not receive the data that successfully need retransmit at UE, and another part is the data (although being out of order) that source eNB has successfully received, and through being given to target eNB before the X2/S1 interface.When target eNB receives first's data, need do the operation of reordering with already present out of order PDCP SDU in the PDCP buffering; Need do the repeated elimination operation with the out of order PDCP SDU that exists in the PDCP buffering when receiving the second portion data.Can find out through above analysis, need do and reorder and the corresponding PDCP SDU of the data of repeated elimination operation is the first kind PDCP SDU that the UE that receives of target eNB resends.

Can learn through above-mentioned analysis; The out of order data that need permutatation and repeated elimination to control are limited; For down link, out of order data are that source eNB sends to UE, but are not confirmed the data that success receives by UE as yet; This partial data is transmitted to target eNB by source eNB, and is sent to UE again by target eNB; For up link, out of order data are that UE sends to source eNB, but are not confirmed the data that success receives by source eNB as yet, and this partial data sends to target eNB once more by UE.Need reorder coboundary with the lower boundary of the SN of the PDCP SDU of repeated elimination operation and SN of receiving terminal (UE or target eNB) as long as know just can be good at controlling reordering and heavily eliminate operational processes out of order data; Therefore need not Flush_timer timer of the prior art, thereby avoid the Flush_timer length of timer that inaccurate technological deficiency is set.Owing to the lower boundary that need reorder with the SN of the PDCP SDU of repeated elimination operation is provided, that is: the lower boundary last_submitted_PDCP_RX_SN of reordering window (the present invention is designated hereinafter simply as lower boundary SN) in the present standard.Therefore as long as receiving terminal can access the coboundary that need reorder with the SN of the PDCP SDU of repeated elimination operation; That is: the coboundary (Upper_line_outorder_PDCP_SN of the SN of out of order PDCP SDU possibly take place; The present invention is designated hereinafter simply as coboundary SN) get final product; Wherein, as one embodiment of the present of invention, the SN that rlc layer will send the pairing PDCP SDU of RLC PDU that does not also send among source eNB or the UE when said coboundary SN is specially and switches subtracts 1.Be specially:

For down link: coboundary SN be the RRC of source eNB when sending switching command (handover_command), the SN of that RLC will send will be new (being different from re-transmission) the PDCP SDU that RLC PDU is corresponding subtracts 1.

For up link: coboundary SN be the RRC of UE when receiving handover_command, the SN of that RLC will send will be new (being different from re-transmission) the PDCP SDU that RLC PDU is corresponding subtracts 1.

Certainly the value of the coboundary SN of Uplink/Downlink that the above embodiment of the present invention proposes is merely the more excellent implementation of the present invention; Also can the coboundary of above-mentioned SN be postponed backward; The time of reordering and heavily eliminating operation with increase; Though may increase the computing of receiving terminal, equally also can reach technique effect of the present invention, the variation of this type also should be included within protection scope of the present invention equally.

In order clearer understanding to be arranged, will be that present invention is described for example with down link and up link respectively below to the present invention.

As shown in Figure 1, reorder and repeated elimination method of operating flow chart for control in the one embodiment of the invention down link, may further comprise the steps:

Step S101, source eNB sends switching command handover_command message to UE, and the SN of the PDCP SDU of the record new RLC PDU correspondence that RLC will send this moment, thereby obtains coboundary SN.

Step S102 sends to receiving terminal UE with the coboundary SN that obtains.Wherein, The present invention proposes multiple mode and can above-mentioned coboundary SN be sent to UE; Following variety of way is merely the more excellent implementation of the present invention; Be not that explanation the present invention only can realize that i.e. the present invention should not be limited to following send mode through following proposal, other similar send modes also should be protection range of the present invention and contain.Further, can earlier coboundary SN be sent to target eNB, send to UE by target eNB again through source eNB; Perhaps directly send it to UE by source eNB.

As one embodiment of the present of invention, can through the X2/S1 interface said coboundary SN be sent to target eNB by source eNB earlier, target eNB is when UE sends data, and the PDCP PDU that this coboundary SN is corresponding sends to UE as first PDCP PDU.Wherein, S1 is used to connect eNB and mobile management entity/gateway, and X2 is used for the connection between the eNB.

As an alternative embodiment of the invention, can through the X2/S1 interface coboundary SN be informed target eNB by source eNB earlier, target eNB sends to UE through status report with said coboundary SN when UE sends data.

As another embodiment of the present invention; Can pass through the X2/S1 interface when the target eNB forwarding data by eNB in the source; The PDCP SDU that coboundary SN is corresponding at first before is given to target eNB; Target eNB is when UE sends data, and the PDCP PDU that this RLC SDU is corresponding sends to UE as first PDCP PDU.

Equally, as another embodiment of the present invention, also can send to UE through handover_command message.In the handover_command message that UE sends, carry said coboundary SN at source eNB, with this coboundary SN as the needs coboundary with the SN of the PDCPSDU of repeated elimination operation of reordering.

Need to prove skew before and after above-mentioned coboundary SN can do according to actual conditions.From foregoing description, can find out in addition how to transmit coboundary SN and mainly be the agreement between UE, source eNB and the target eNB, therefore also can send above-mentioned coboundary SN to UE through other means, same the present invention also is not limited to above-mentioned four kinds of modes.Those skilled in the art can understand that above-mentioned four kinds of modes only are in order better to understand the present invention, rather than restriction the present invention, therefore other of above-mentioned send mode are changed also should be protection range of the present invention and contain.

Step S103, UE reorders and the repeated elimination operation termination time according to the coboundary SN control PDCP layer that receives.Because UE end PDCP layer is to guarantee can successfully submit to the upper strata according to the order of sequence when source eNB is given to the first kind SDU of target eNB before through the X2/S1 interface receiving, just can realize control with the coboundary to the PDCP layer reorders and repeated elimination is operated as long as therefore know the lower boundary that need reorder with the PDCP SDU SN of repeated elimination operation.

As shown in Figure 2, reorder and repeated elimination method of operating flow chart for control in the another embodiment of the present invention up link, may further comprise the steps:

Step S201, source eNB sends switching command (handover_command message) to UE.

Step S202, the rrc layer of UE are after receiving switching command, and RLC writes down the SN of the PDCP SDU of the new RLC PDU correspondence that will send this moment, thereby obtains coboundary SN.

Step S203, UE sends to the receiving terminal target eNB with the coboundary SN that obtains.Wherein, the present invention has proposed three kinds of modes too and has sent coboundary SN by UE to target eNB.

As one embodiment of the present of invention, can be by UE when target eNB be sent data, the PDCP PDU that coboundary SN is corresponding sends to target eNB as first PDCP PDU.

As an alternative embodiment of the invention, can through status report coboundary SN be sent to target eNB by UE when target eNB is sent data.

As another embodiment of the present invention, UE confirms that through switching (handover_confirm) message is to target eNB transmission coboundary SN.In the handover_confirm message that target eNB is sent, carry coboundary SN at UE, target eNB with this coboundary SN as the needs coboundary with the SN of the PDCP SDU of repeated elimination operation of reordering.Skew before and after same above-mentioned coboundary SN can do according to actual conditions.

Step S204, target eNB reorders and the repeated elimination operation termination time according to the coboundary SN control PDCP layer that receives.Because target eNB will guarantee target eNB and when receiving the first kind PDCP SDU that UE resends, can submit to the upper strata according to the order of sequence, only need know that therefore the lower boundary that out of order PDCP SDU SN possibly take place just can realize the control to the PDCP layer reorders and repeated elimination is operated with the coboundary.

An embodiment as said method of the present invention; The deadlock situation that occurs in the handoff procedure; One timer can be set; This timer can be got bigger value as timing, and same end is reordered and the repeated elimination operation behind this timer expiry, and this timer also can adopt Flush_timer timer of the prior art.But issuable problem is when adopting the Flush_timer timer: overtime or other reasons is dropped if PDCP SDU is owing to discard_timer in the handoff procedure, then can cause the PDCP SDU of its back to delay time to the upper strata and submit.

Therefore, in order to prevent this from occurring, another embodiment of the present invention also proposes a kind of method that prevents deadlock.Also be provided with a timer among same this embodiment, be specially: start timer when current handoff procedure begins, this is timer-operated to be to receive to be right after pairing SDU time that SDU is used of back of lower boundary SN.When this SDU is received, upgrade said lower boundary SN, and the replacement timer.Need to prove that the present invention is not limited to receive SDU at every turn all will upgrade lower boundary SN, but for example also the compartment of terrain upgrade lower boundary SN.If timer expiry, then the corresponding SDU of expression does not successfully receive, and upgrades lower boundary SN so, and the replacement timer.At this moment lower boundary SN is made as the corresponding SN of the previous PDCP SDU that has received of the next SDU gap (gap) that does not receive, possibly comprise a plurality of continuous SDU that do not receive among one of them SDU gap.This process is up to lower boundary SN >=stop during the SN of coboundary.At this moment, stop reordering and the repeated elimination operation of PDCP layer.Simultaneously, in order to guarantee the reception of crucial SDU (PDCPSDU that coboundary SN is indicated), uplink downlink can require corresponding receiving terminal return state report after sending this SDU.

In the above-described embodiments; Value about timer: the effect of timer is not the termination time that is used for directly control ordering and repeated elimination operation; But prevent that overtime or other reasons abandons the deadlock that occurs to PDCP SDU owing to Discard_timer, so value can be made as the integral multiple of the Discard_timer value of configuration.

The method that the present invention proposes not only can effectively be accomplished ordering and repeated elimination operation; When avoiding adopting Flush_timer mechanism; Thereby amount of calculation increase that causes owing to value is inaccurate and the out of order problem that causes thereof have also been avoided; Simultaneously, the present invention also provides the obtaining value method to used timer.

Corresponding to said method, the present invention also proposes a kind of control and reorders and the repeated elimination operated system, and its structure chart is as shown in Figure 3, and this system comprises UE100, source eNB200 and target eNB 300.UE100 is used for when switching the coboundary SN of upstream data is sent to target eNB 300; And after switching the coboundary SN of downlink data receiving, and downlink data is reordered the termination time with the repeated elimination operation according to the coboundary SN control of the downlink data that receives.Target eNB 300 is used for the termination time that SN control in coboundary is reordered to upstream data and repeated elimination is operated according to the upstream data of UE100 transmission.Source eNB200 is used for after sending switching command the coboundary SN of downlink data is sent to UE100, or is transmitted to UE100 through target eNB 300.

The present invention also proposes a kind of receiving terminal, and its structure is as shown in Figure 4, and this receiving terminal can reorder and the repeated elimination operation according to the coboundary SN control that receives, and for down link, this receiving terminal is UE; And for up link, this receiving terminal is a target eNB.This receiving terminal 400 comprises receiver module 410 and control module 420, and receiver module 410 is used for after switching, receiving coboundary SN, and this coboundary SN is the coboundary that the SN of out of order PDCP SDU possibly take place; Control module 420 is used for confirming according to the coboundary SN that receiver module 410 receives the termination time of permutatation and repeated elimination operation.Wherein, when said receiving terminal was UE, the SN of the PDCP SDU that the new RLC PDU that the RLC that said coboundary SN is source eNB will send when sending switching command message is corresponding subtracted 1; When said receiving terminal was target eNB, the SN of the PDCP SDU that the new RLC PDU that the RLC that said coboundary SN is UE will send when receiving switching command message is corresponding subtracted 1.

As an embodiment of said method of the present invention, this receiving terminal also comprises time block 430, be used at the overtime renewal lower boundary of timing SN, and the said timer of resetting, said timing can preestablish, and can avoid occurring in the handoff procedure deadlock.

For above-mentioned time block 430; The invention allows for a kind of implementation method; This time block 430 is used to control the required time of next SDU that receives the corresponding PDCP SDU of lower boundary SN, when time block 430 overtime, and when not receiving next SDU; More the lower boundary SN of new record is the corresponding SN of the previous PDCP SDU that has received of the next SDU gap that does not receive; The replacement timer, and continue to receive SDU, a plurality of continuous SDU that do not receive possibly comprised among one of them SDU gap.And when the lower boundary SN of receiving terminal 400 record >=coboundary SN, stop reordering and the repeated elimination operation.So in this way, not only can avoid the deadlock situation that occurs in the handoff procedure, can also effectively avoid postponing the problem submitted owing to some PDCP PDU is dropped the PDCP PDU that causes its back.

Although illustrated and described embodiments of the invention; For those of ordinary skill in the art; Be appreciated that under the situation that does not break away from principle of the present invention and spirit and can carry out multiple variation, modification, replacement and modification that scope of the present invention is accompanying claims and be equal to and limit to these embodiment.

Claims

1. a control is reordered and the repeated elimination method of operating, it is characterized in that, may further comprise the steps:

Receiving terminal receives coboundary sequence number SN after switching, said coboundary SN is the coboundary that the SN of out of order data convergence protocol service data cell PDCP SDU possibly take place;

Said receiving terminal is confirmed the termination time of permutatation and repeated elimination operation according to the said coboundary SN that receives.

2. control is reordered and the repeated elimination method of operating according to claim 1, it is characterized in that said receiving terminal is a user equipment (UE), and said UE receives coboundary SN and is specially after switching:

The source evolution base station eNB sends to target eNB with said coboundary SN through the X2/S1 interface;

Said target eNB is when said UE sends data, and the PDCP PDU that said coboundary SN is corresponding sends to said UE as first PDCP PDU.

3. control is reordered and the repeated elimination method of operating according to claim 1, it is characterized in that said receiving terminal is UE, and said UE receives coboundary SN and is specially after switching:

Said source eNB sends to target eNB with said coboundary SN through the X2/S1 interface;

Said target eNB sends to UE through status report with said coboundary SN when said UE sends data.

4. control is reordered and the repeated elimination method of operating according to claim 1, it is characterized in that said receiving terminal is UE, and said UE receives coboundary SN and is specially after switching:

During to said target eNB forwarding data, be given to said target eNB before the PDCP SDU that said source eNB is corresponding with said coboundary SN is preferential through the X2/S1 interface at said source eNB;

Said target eNB is sent as first PDCP PDU the corresponding PDCP PDU of said PDCP SDU that receives when said UE sends data to UE.

5. control is reordered and the repeated elimination method of operating according to claim 1, it is characterized in that said receiving terminal is UE, and said UE receives coboundary SN and is specially after switching:

Said source eNB sends to said UE through switching command message with said coboundary SN.

6. each said control is reordered and the repeated elimination method of operating like claim 2-5, it is characterized in that, the RRC that said coboundary SN is source eNB is when sending switching command message, and the SN of the PDCP SDU that the new RLC PDU that RLC will send is corresponding subtracts 1.

7. control is reordered and the repeated elimination method of operating according to claim 1, it is characterized in that said receiving terminal is a target eNB, and said target eNB receives said coboundary SN and is specially after switching:

Said UE is when said target eNB is sent data, and the PDCPPDU that coboundary SN is corresponding sends to target eNB as first PDCP PDU.

8. control is reordered and the repeated elimination method of operating according to claim 1, it is characterized in that said receiving terminal is a target eNB, and said target eNB receives said coboundary SN and is specially after switching:

Said UE sends to said target eNB through status report with said coboundary SN when said target eNB is sent data.

9. control is reordered and the repeated elimination method of operating according to claim 1, it is characterized in that said receiving terminal is a target eNB, and said target eNB receives said coboundary SN and is specially after switching:

Said UE sends said coboundary SN through switch acknowledgment message to said target eNB.

10. each said control is reordered and the repeated elimination method of operating like claim 7-9, it is characterized in that, the RRC that said coboundary SN is UE is when receiving switching command message, and the SN of the PDCP SDU that the new RLC PDU that RLC will send is corresponding subtracts 1.

11. control is reordered and the repeated elimination method of operating according to claim 1, it is characterized in that, also comprises:

Startup reorder with repeated elimination operation after, start timer, lower boundary SN is upgraded in the overtime back of the timing of said timer, and the said timer of resetting, said timing preestablishes.

12. control is reordered and the repeated elimination method of operating according to claim 1, it is characterized in that, also comprises:

Startup reorder with repeated elimination operation after, start timer, the timing of said timer is used to control the required time of next SDU that receives the corresponding PDCP SDU of lower boundary SN;

Receive the next SDU of the corresponding PDCP SDU of lower boundary SN at said receiving terminal after, the said timer of resetting;

When said timer expiry; And when not receiving the next SDU of the corresponding PDCP SDU of lower boundary SN; The more said lower boundary SN of new record is the corresponding SN of the previous PDCP SDU that has received of the next SDU gap that does not receive, the said timer of resetting, and continue to receive SDU.

13. said control is reordered and the repeated elimination method of operating like claim 12, it is characterized in that, also comprises:

When the lower boundary SN of said receiving terminal record >=coboundary SN, stops said reorder and repeated elimination is operated.

14. a control is reordered and the repeated elimination operated system, it is characterized in that, comprises UE, source eNB and target eNB,

Said UE; Be used for when switching the coboundary SN of upstream data is sent to target eNB; And after switching the coboundary SN of downlink data receiving, and downlink data is reordered the termination time with the repeated elimination operation according to the coboundary SN control of the downlink data that receives;

Said target eNB is used for the termination time that SN control in coboundary is reordered to upstream data and repeated elimination is operated according to the upstream data of said UE transmission;

Said source eNB is used for after sending switching command the coboundary SN of downlink data is sent to said UE, or is transmitted to said UE through target eNB.

15. a receiving terminal is used for reordering and the repeated elimination operation according to the coboundary SN control that receives, and it is characterized in that, comprises receiver module and control module,

Said receiver module is used for after switching, receiving coboundary SN, and said coboundary SN is the coboundary that the SN of out of order PDCP SDU possibly take place;

Said control module is used for confirming the termination time that permutatation and repeated elimination are operated according to the said coboundary SN that said receiver module receives.

16., it is characterized in that when said receiving terminal was UE, the RRC that said coboundary SN is source eNB was when sending switching command message like the said receiving terminal of claim 15, the SN of the PDCP SDU that the new RLC PDU that RLC will send is corresponding subtracts 1.

17., it is characterized in that when said receiving terminal was target eNB, the RRC that said coboundary SN is UE was when receiving switching command message like the said receiving terminal of claim 15, the SN of the PDCP SDU that the new RLC PDU that RLC will send is corresponding subtracts 1.

18., it is characterized in that like the said receiving terminal of claim 15, also comprise time block, be used for upgrading lower boundary SN in the overtime back of timing, and the said timer of resetting, said timing preestablishes.

19. like the said receiving terminal of claim 15, it is characterized in that, also comprise time block; Be used to control the required time of next SDU that receives the corresponding PDCP SDU of lower boundary SN; Overtime when said time block, and when not receiving next SDU, the more said lower boundary SN of new record is the corresponding SN of the previous PDCP SDU that has received of the next SDU gap that does not receive; The said timer of resetting; And continue to receive SDU, and when the lower boundary SN of record >=coboundary SN, stop reordering and the repeated elimination operation.

20. an eNB is characterized in that, comprises claim 15,17,18 or 19 described receiving terminals.

21. a UE is characterized in that, comprises claim 15,16,18 or 19 described receiving terminals.