CN101771521B

CN101771521B - Management method of status report retransmission timer in buffer zone

Info

Publication number: CN101771521B
Application number: CN 200910076216
Authority: CN
Inventors: 陈思; 贺美芳; 张健; 戴谦
Original assignee: ZTE Corp
Current assignee: Ge Wei
Priority date: 2009-01-06
Filing date: 2009-01-06
Publication date: 2013-11-06
Anticipated expiration: 2029-01-06
Also published as: CN101771521A

Abstract

The invention discloses a management method of a status report retransmission timer in a buffer zone, which comprises the following steps: stopping an RETX-BSR-TIMER when a Regular BSB is triggered; or, restarting the RETX-BSR-TIMER when the Regular BSB is triggered; or, when the RETX-BSR-TIMER is overtime, determining that a processing SR exists in UE, then the Regular BSB is not triggered; or, stopping the RETX-BSR-TIMER during SR, or, when the SR is triggered, restarting the RETX-BSR-TIMER. The method of the invention can reduce the rate of generating unnecessary SR.

Description

Management method of buffer status report retransmission timer

Technical Field

The invention relates to the technical field of digital mobile communication, in particular to a management method of a buffer status report retransmission timer.

Background

A structure of a Radio interface protocol uplink layer 2 of an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) in a Long Term Evolution (LTE) system is shown in fig. 1, where the Radio interface protocol uplink layer 2 is composed of a plurality of base stations (enbs), and a Media Access Control (MAC) protocol layer includes a Scheduling/Priority processing (Scheduling/Priority processing) functional entity and a hybrid automatic repeat request (HARQ) functional entity; the eNB implements an uplink Scheduling function and a Priority processing function through a Scheduling/Priority handling functional entity, and the implementation of the uplink Scheduling function and the Priority processing function also requires a Buffer Status Report (BSR) including a Buffer data condition of each Logical Channel Group (LCG) reported by a User Equipment (UE).

The BSR is classified into three types according to different triggering conditions: regular buffer status report (Regular BSR), Padding buffer status report (Padding BSR), and Periodic buffer status report (Periodic BSR).

Wherein, the triggering conditions of the Regular BSR include: new data to be transmitted reaches an empty buffer, data to be transmitted from an upper layer of a high-priority logic channel reaches the buffer, a serving cell of the UE changes, a BSR retransmission TIMER (RETX _ BSR _ TIMER) is overtime, and the buffer has data to be transmitted;

here, the rettx _ BSR _ TIMER is used to solve a problem that, in the BSR transmission process, if the BSR is lost, the harq functional entity retransmits the BSR, so that the BSRs do not arrive at the eNB in sequence, and the eNB cannot determine which BSR is the latest, and does not allocate uplink Shared Channel (UL-SCH) resources for transmitting the BSR to the UE, so that the UE cannot transmit the BSR due to the long-term inability to obtain UL-SCH resources; the current processing procedure for RETX BSR TIMER includes: when the BSR is sent, RETX _ BSR _ TIMER is started; after the start, when receiving the uplink Grant (UL Grant) or sending the BSR again, the RETX BSR TIMER is restarted, and when the RETX BSR TIMER times out and the buffer has to transmit data, the Regular BSR is triggered.

The triggering conditions of Padding BSR include: the UE has obtained an uplink resource, where padding bits in the uplink resource are greater than or equal to a size of a BSR Control layer Control Element (MAC CE, MAC Control Element), and no Regular BSR or Periodic BSR is to be sent in the buffer.

Triggering conditions for the period BSR include: the BSR cycle TIMER (period BSR TIMER) times out.

The Regular BSR may trigger a Scheduling Request (SR). The SR is used to request the eNB to allocate UL-SCH resources to the UE, the SR is transmitted on a Physical Uplink Control Channel (PUCCH), and the eNB allocates PUCCH resources to the UE in advance.

After the Regular BSR triggers the SR, the procedure for requesting the eNB to allocate UL-SCH resources by processing the SR is as follows:

step 1, in a transmission interval (TTI), a Regular BSR triggers an SR, and the UE does not have the SR in processing, step 2 is executed, and the SR starts to be processed; if so, not processing the SR, namely the SR is in a suspension state, and canceling the SR until the flow of processing the processed SR is finished;

step 2, marking the SR as SR1, clearing 0 in an SR counter, judging whether the UE has PUCCH resources, and if so, executing step 3; otherwise, executing step 9;

step 3, transmitting the SR, adding 1 to the SR counter, and executing step 9;

step 4, determining whether the UL Grant is received in the current TTI, and if the UL Grant is received, executing step 5; if not, executing step 6;

step 5, canceling all SRs and ending the processing flow;

wherein, all the SRs include the SR processed in the current processing flow and the SR triggered by the Regular BSR in the current processing flow, and the SR triggered by the Regular BSR in the current processing flow is the SR in a suspension state;

step 6, judging whether the UE has PUCCH resources, if so, executing step 7; if not, executing step 9;

step 7, judging whether the current value of the counter is equal to the preset maximum transmission times of the SR, if so, releasing PUCCH resources, and executing step 8; otherwise, returning to the step 3;

step 8, canceling all SRs, ending the processing flow, and enabling the UE to enter a random access process;

and 9, when the current TTI is finished and the next TTI is entered, considering the next TTI as the current TTI, and returning to the step 4.

As can be seen from the above process, the SRs triggered in the primary SR processing flow are all in a suspended state, and have no influence on the primary SR processing flow, that is, there is no help in requesting to allocate UL-SCH resources to the UE, and the SR is unnecessary. However, when the RETX _ BSR _ TIMER times out in the processing flow of a certain SR and triggers the SR, the unnecessary SR is generated.

Disclosure of Invention

In view of the above, the main objective of the present invention is to provide a method for managing a buffer status report retransmission timer, which can reduce the probability of generating unnecessary SR.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

a method for managing a buffer status report retransmission timer, the method comprising:

when User Equipment (UE) triggers a Regular buffer status report (Regular BSR), stopping a BSR retransmission TIMER RETX _ BSR _ TIMER; or,

when UE triggers Regular BSR, restarting RETX _ BSR _ TIMER; or,

when RETX _ BSR _ TIMER is over time, determining that the UE has a scheduling request SR which is processed, and not triggering a Regular BSR; or,

when the UE triggers the SR, stopping RETX _ BSR _ TIMER; or,

when the UE triggers SR, RETX _ BSR _ TIMER is restarted.

Further, before triggering Regular BSR, the method further comprises:

sending a Buffer Status Report (BSR), and starting or restarting RETX _ BSR _ TIMER;

and restarting RETX _ BSR _ TIMER when the uplink Grant UL Grant is received.

Further, after stopping RETX _ BSR _ TIMER when triggering Regular BSR, the method further includes:

a1, judging whether the current transmission interval TTI has uplink shared channel UL-SCH resources, if yes, executing step B1; if not, go to step C1;

b1, transmitting BSR on UL-SCH resources, and starting RETX _ BSR _ TIMER;

c1, triggering SR by the Regular BSR, executing the SR processing flow, if receiving UL Grant in the SR processing flow, executing step B1; and if the SR processing flow is finished and the ULGrant is not received yet, the UE enters a random access process.

Further, after restarting RETX _ BSR _ TIMER when triggering Regular BSR, the method further includes:

a2, judging whether the current TTI has UL-SCH resource, if yes, executing step B2; if not, go to step C2;

b2, transmitting BSR on UL-SCH resources, and restarting RETX _ BSR _ TIMER;

c2, triggering SR by the Regular BSR, executing the SR processing flow, and restarting RETX _ BSR _ TIMER if UL Grant is received in the SR processing flow; step B2 is executed; if the SR processing flow is finished and the UL Grant is not received yet, the UE enters a random access procedure.

Further, if it is determined that the UE has the SR being processed, the Regular BSR is not triggered as:

judging whether the processed SR exists in the UE, if so, not triggering a Regular BSR; if not, a Regular BSR is triggered.

Further, the stopping RETX _ BSR _ TIMER when SR is triggered comprises the following steps:

a3, judging whether the current TTI has UL-SCH resource, if yes, executing step B3; if not, go to step C3;

b3, transmitting BSR on UL-SCH resources, and starting RETX _ BSR _ TIMER;

c3, the Regular BSR triggers SR, stops RETX _ BSR _ TIMER, executes the SR processing flow, if receives UL Grant in the SR processing flow, executes step B3; if the SR processing flow is finished and the UL Grant is not received yet, the UE enters a random access procedure.

Further, the restarting RETX _ BSR _ TIMER when SR is triggered comprises:

a4, judging whether the current TTI has UL-SCH resource, if yes, executing step B4; if not, go to step C4;

b4, transmitting BSR on UL-SCH resources, and restarting RETX _ BSR _ TIMER;

c4, triggering SR by the Regular BSR, restarting RETX _ BSR _ TIMER, executing the SR processing flow, restarting RETX _ BSR _ TIMER if UL Grant is received in the SR processing flow, and executing step B4; if the SR processing flow is finished and the UL Grant is not received yet, the UE enters a random access procedure.

The management method of the buffer status report retransmission timer provided by the invention has the following advantages and characteristics:

according to the method, when the Regular BSR is triggered, the SR is triggered, or the RETX BSR TIMER is overtime, the RETX BSR TIMER is stopped, restarted, or triggered, and the like, so that the RETX BSR TIMER is not overtime in the SR processing flow, or the Regular BSR is not triggered when the RETX BSR TIMER is overtime, the condition that the Regular BSR is triggered in the SR processing flow is further reduced or even eliminated, and the probability of generating unnecessary SR is reduced.

Drawings

FIG. 1 is a diagram illustrating a structure of an uplink layer 2 of a radio interface protocol of an E-UTRAN in an LTE system;

FIG. 2 is a flowchart illustrating a method for managing a buffer status report retransmission timer according to an embodiment of the present invention;

FIG. 3 is a flowchart illustrating a method for managing a retransmission timer of a second buffer status report according to an embodiment of the present invention;

FIG. 4 is a flowchart illustrating a method for managing a retransmission timer of a triple buffer status report according to an embodiment of the present invention;

FIG. 5 is a flowchart illustrating a method for managing a four-buffer status report retransmission timer according to an embodiment of the present invention;

fig. 6 is a flowchart of an implementation of a management method for a five-buffer status report retransmission timer according to an embodiment of the present invention.

Detailed Description

The basic idea of the invention is as follows: by stopping/restarting the BSR retransmission TIMER RETX _ BSR _ TIMER when the Regular BSR is triggered, or by determining that the UE has the SR in processing when the RETX _ BSR _ TIMER is overtime, the Regular BSR is not triggered, or by stopping/restarting the RETX _ BSR _ TIMER when the SR is triggered, the RETX _ BSR _ TIMER is not overtime in the SR processing flow, or the Regular BSR is not triggered when the RETX _ BSR _ TIMER is overtime, so that the condition that the Regular BSR is triggered in the SR processing flow can be reduced or even eliminated, and the probability of generating unnecessary SR is reduced.

The implementation flow of the management method for the buffer status report retransmission timer according to the embodiment of the present invention is shown in fig. 2, and includes the following steps:

step 201: the transmitted BSR starts RETX _ BSR _ TIMER;

step 202: the UE triggers a BSR, and if the BSR is a Regular BSR, performs step 203; if the BSR is not a Regular BSR, step 205 is performed.

Step 203: stopping RETX _ BSR _ TIMER, and executing step 204;

step 204: judging whether the current TTI has UL-SCH resource, if so, executing step 2041; if not, go to step 2042;

step 2041: sending a BSR on UL-SCH resources, starting RETX _ BSR _ TIMER, canceling all triggered BSRs, and performing step 2052;

step 2042: the Regular BSR triggers the SR, executes the process flow of the SR, and if the UL Grant is received in the process flow of the SR, executes step 2041; if the SR processing flow is finished and the UL Grant is not received yet, the UE enters a random access process;

step 205, judging whether the current TTI has UL-SCH resource, if so, executing step 2051; if not, go to step 2052;

step 2051: sending a BSR on UL-SCH resources, restarting RETX _ BSR _ TIMER, canceling all triggered BSRs, and performing step 2052; here, all triggered BSRs refer to all BSRs in the current UE;

step 2052: in a timing period of RETX _ BSR _ TIMER, if UE triggers BSR, returning to step 202, and if UL Grant is received, restarting RETX _ BSR _ TIMER; when RETX _ BSR _ TIMER is overtime and the buffer has data to be transmitted, triggering a Regular BSR, and returning to step 203;

in the first embodiment of the present invention, when the UE triggers the Regular BSR, that is, stops the RETX _ BSR _ TIMER, and when the Regular BSR is sent or the UL Grant is received, the RETX _ BSR _ TIMER is started, so that the RETX _ BSR _ TIMER is stopped to time in the whole SR processing flow, thereby ensuring that the RETX _ BSR _ TIMER is not timed out in the SR processing flow, and further unnecessary SRs are not generated.

The implementation flow of the management method of the second buffer status report retransmission timer according to the embodiment of the present invention is shown in fig. 3, and includes the following steps:

step 301: the transmitted BSR starts RETX _ BSR _ TIMER;

step 302: the UE triggers a BSR, and if the BSR is a Regular BSR, performs step 303; if the BSR is not a Regular BSR, step 305 is performed.

Step 303: restarting RETX _ BSR _ TIMER;

step 304: judging whether the current TTI has UL-SCH resource, if so, executing step 3041; if not, go to step 3042;

step 3041: sending BSR on UL-SCH resource, restarting RETX _ BSR _ TIMER, canceling all triggered BSR, and executing step 3052;

step 3042: the Regular BSR triggers the SR, the SR processing flow is executed, if the UL Grant is received in the SR processing flow, the step 303 is returned; if the SR processing flow is finished and the UL Grant is not received yet, the UE enters a random access process;

step 305: judging whether the current TTI has UL-SCH resources, if so, executing step 3051; if not, go to step 3052;

step 3051: sending BSR on UL-SCH resource, restarting RETX _ BSR _ TIMER, canceling all triggered BSR, and executing step 3052; here, all triggered BSRs refer to all BSRs in the current UE;

step 3052: in a timing period of RETX _ BSR _ TIMER, if UE triggers BSR, returning to step 302, and if UL Grant is received, restarting RETX _ BSR _ TIMER; when the rettx _ BSR _ TIMER times out and the buffer has data to transmit, the Regular BSR is triggered, and the process returns to step 303.

In the second embodiment of the present invention, when the UE triggers the Regular BSR, that is, the RETX BSR TIMER is restarted, so that the restart time of the RETX BSR TIMER approaches the time of starting the processing flow of the SR, and thus, when the timing cycle of the RETX BSR TIMER is greater than the maximum time required for completing the processing flow of the SR, that is, the product of the transmission cycle of the SR and the maximum transmission frequency, the RETX BSR TIMER does not time out in the processing flow of the SR, and thus, unnecessary SRs are not generated, and the probability of generating unnecessary SRs is reduced.

The implementation flow of the management method of the three-buffer status report retransmission timer in the embodiment of the invention is shown in fig. 4, and comprises the following steps:

step 401: the transmitted BSR starts RETX _ BSR _ TIMER;

step 402: when the RETX _ BSR _ TIMER is overtime and data to be transmitted is cached, determining whether the UE has an SR being processed, if so, that is, at the time when the RETX _ BSR _ TIMER is overtime, the UE is executing a process flow of the SR, and performing step 403; if not, that is, at the time when the RETX _ BSR _ TIMER is overtime, the UE is not executing the SR process flow, and step 404 is executed;

step 403: the Regular BSR is not triggered, RETX _ BSR _ TIMER is restarted, and the step 402 is returned;

step 404: triggering a Regular BSR, judging whether the current TTI has UL-SCH resources, if so, executing a step 4041; if not, go to step 4042;

step 4041: sending BSR on UL-SCH resource, restarting RETX _ BSR _ TIMER, canceling all triggered BSR, and returning to step 402; here, all triggered BSRs refer to all BSRs in the current UE;

step 4042: the Regular BSR triggers the SR, the SR processing flow is executed, if the UL Grant is received in the SR processing flow, the RETX _ BSR _ TIMER is restarted, and step 4041 is executed; if the SR processing flow is finished and the UL Grant is not received yet, the UE enters a random access process;

in the third embodiment of the present invention, it is ensured that unnecessary SR is not generated in the SR processing flow by not triggering Regular BSR when the RETX _ BSR _ TIMER times out in the SR processing flow.

The implementation flow of the management method of the four-buffer status report retransmission timer according to the embodiment of the present invention is shown in fig. 5, and includes the following steps:

step 501: the transmitted BSR starts RETX _ BSR _ TIMER;

step 502: the UE triggers a BSR, and if the BSR is a Regular BSR, performs step 503; if the BSR is not a Regular BSR, go to step 505;

step 503: judging whether the current TTI has UL-SCH resource, if so, executing a step 5041; if not, go to step 5042;

step 5041: sending BSR on UL-SCH resource, starting RETX _ BSR _ TIMER, canceling all triggered BSR, and executing step 5052;

step 5042: the Regular BSR triggers the SR, stops RETX _ BSR _ TIMER, executes the process flow of the SR, and if the UL Grant is received in the process flow of the SR, executes step 5041; if the SR processing flow is finished and the UL Grant is not received yet, the UE enters a random access process;

step 505: judging whether the current TTI has UL-SCH resource, if so, executing a step 5051; if not, step 5052 is performed;

step 5051: sending BSR on UL-SCH resource, restarting RETX _ BSR _ TIMER, canceling all triggered BSR, and executing step 5052; here, all triggered BSRs refer to all BSRs in the current UE;

step 5052: in a timing period of RETX _ BSR _ TIMER, if the UE triggers BSR, returning to step 502, and if the UL Grant is received, restarting RETX _ BSR _ TIMER; when the rettx BSR TIMER times out and the buffer has data to transmit, the Regular BSR is triggered, and the process returns to step 503.

In the fourth embodiment of the present invention, by triggering the SR, that is, stopping the RETX _ BSR _ TIMER, and starting the RETX _ BSR _ TIMER when the Regular BSR is sent or the UL Grant is received, the RETX _ BSR _ TIMER is stopped to time in the whole SR processing flow, which ensures that the RETX _ BSR _ TIMER is not timed out in the SR processing flow, and thus unnecessary SRs are not generated.

The implementation flow of the management method of the five-buffer status report retransmission timer in the embodiment of the present invention is shown in fig. 6, and includes the following steps:

step 601: the transmitted BSR starts RETX _ BSR _ TIMER;

step 602: the UE triggers a BSR, and if the BSR is a Regular BSR, performs step 603; if the BSR is not a Regular BSR, go to step 605;

step 603: judging whether the current TTI has UL-SCH resource, if so, executing step 6041; if not, go to step 6042;

step 6041: sending BSR on UL-SCH resource, restarting RETX _ BSR _ TIMER, canceling all triggered BSR, and executing step 6052;

step 6042: the Regular BSR triggers SR, restarts RETX _ BSR _ TIMER, executes the process flow of SR, restarts RETX _ BSR _ TIMER if UL Grant is received in the process flow of SR, and executes step 6041; if the SR processing flow is finished and the UL Grant is not received yet, the UE enters a random access process;

step 605: judging whether the current TTI has UL-SCH resource, if so, executing step 6051; if not, go to step 6052;

step 6051: sending BSR on UL-SCH resource, restarting RETX _ BSR _ TIMER, canceling all triggered BSR, and executing step 6052; here, all triggered BSRs refer to all BSRs in the current UE;

step 6052: in a timing period of RETX _ BSR _ TIMER, if the UE triggers BSR, returning to step 602, and if the UL Grant is received, restarting RETX _ BSR _ TIMER; when the RETX _ BSR _ TIMER times out and the buffer has data to transmit, the Regular BSR is triggered, and the process returns to step 603.

In the fifth embodiment of the present invention, when the UE triggers the SR, the RETX _ BSR _ TIMER is restarted, so that the restart time of the RETX _ BSR _ TIMER is close to the time when the processing flow of the SR starts, and thus, the timing cycle of the RETX _ BSR _ TIMER is not less than the maximum time required for completing the processing flow of the SR, that is, when the product of the transmission cycle of the SR and the maximum transmission frequency is obtained, the RETX _ BSR _ TIMER does not time out in the processing flow of the SR, and thus, unnecessary SRs are not generated, and the probability of generating unnecessary SRs is reduced.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention.

Claims

1. A method for managing a buffer status report retransmission timer, the method comprising:

when User Equipment (UE) triggers a Regular buffer status report (Regular BSR), stopping a BSR retransmission TIMER RETX _ BSR _ TIMER;

after stopping RETX _ BSR _ TIMER when the Regular BSR is triggered, the method further includes:

b1, transmitting BSR on UL-SCH resources, and starting RETX _ BSR _ TIMER;

c1, triggering a scheduling request SR by a Regular BSR, executing the processing flow of the SR, and if receiving an uplink Grant UL Grant in the processing flow of the SR, executing the step B1; if the SR processing flow is finished and the UL Grant is not received yet, the UE enters a random access process; or,

when UE triggers Regular BSR, restarting RETX _ BSR _ TIMER;

after restarting RETX _ BSR _ TIMER when the Regular BSR is triggered, the method further comprises the following steps:

b2, transmitting BSR on UL-SCH resources, and restarting RETX _ BSR _ TIMER;

2. The method for managing the buffer status report retransmission timer according to claim 1, wherein before triggering the Regular BSR, the method further comprises:

and restarting RETX _ BSR _ TIMER when the uplink Grant UL Grant is received.