CN103369509B

CN103369509B - A kind of reporting cached state method and terminal device

Info

Publication number: CN103369509B
Application number: CN201210087962.6A
Authority: CN
Inventors: 姚君
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2012-03-29
Filing date: 2012-03-29
Publication date: 2018-02-27
Anticipated expiration: 2032-03-29
Also published as: CN103369509A; WO2013143474A1

Abstract

The invention discloses a kind of reporting cached state method and terminal device, when reaching new up data to be transferred in wireless spread-spectrum technology (RLC) entity or PDCP (PDCP) entity of terminal device and being unsatisfactory for conventional cache state report (BSR) and cycle BSR condition, the new buffer status report of the up buffer data size information for indicating the terminal device is triggered；Or trigger conventional BSR when in the RLC entities or PDCP entities of terminal device reaching new up data to be transferred；Or the duration for retransmitting BSR timers is set to be less than or equal to the minimum period that the time division duplex of time division duplex long evolving system configures.The improved reporting cached state method that this programme proposes, can improve promptness and accuracy that network side knows upstream data amount, network side is understood the True Data amount situation of terminal device in time, and be unlikely to cause signaling overload occur.

Description

Buffer status reporting method and terminal equipment

Technical Field

The present invention relates to the field of communications, and in particular, to a buffer status reporting method and a terminal device.

Background

The current Long Term Evolution (LTE) technology, Worldwide Interoperability for Microwave Access (Wimax), and Ultra Mobile Broadband (UMB) systems all have two duplex modes: frequency Division Duplex (FDD) mode and Time Division Duplex (TDD) mode. In the FDD scheme, the uplink and downlink employ different frequency bands for simultaneous data transmission, while in the TDD scheme, the uplink and downlink employ the same frequency band for time-sharing data transmission.

In a wireless system that performs data transmission in units of Radio frames (Radio frames), the uplink/downlink of Radio over-the-air transmission generally performs data transmission in units of Radio frames, where each Radio Frame is composed of a plurality of subframes (subframes). For the LTE system, the subframes are each composed of an Orthogonal frequency division Multiplexing (Orthogonal frequency division Multiplexing) Symbol (Symbol) as a basic unit, and each radio frame is composed of 10 subframes.

The resource allocation of the uplink/downlink subframe of the FDD system is relatively independent, that is, the resource allocation can be performed on the downlink subframe and the uplink subframe respectively. In the TDD system, a plurality of subframes of a radio frame can be divided into uplink subframes and downlink subframes according to a certain ratio according to the needs of services, and the ratio of the number of the uplink subframes to the number of the downlink subframes in the general TDD system is of a plurality of types so as to meet the needs of different service types. According to the requirements of different region service types, the appropriate uplink and downlink proportion configuration is selected, which is beneficial to improving the frequency spectrum efficiency of the TDD system. For example, for an area with more data downloading services, the configuration with more downlink subframes can be selected; for areas with more uploading services, the configuration with more uplink subframes can be selected; for the areas with balanced uplink and downlink traffic, the proportion configuration with almost the same uplink and downlink subframes can be selected.

In the current LTE TDD (TD-LTE for short) system, 7 modes are set for uplink and downlink configuration of the TDD system, as shown in table 1 below. One radio frame includes 10 subframes, and subframe numbers are respectively marked as: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, wherein "D" indicates that the subframe is a downlink subframe; "U" indicates that the subframe is an uplink subframe; "S" indicates that the subframe is a special subframe, i.e., the subframe includes a downlink transmission part, a guard interval, and an uplink transmission part.

Table 1: existing uplink and downlink configuration list in TD-LTE system

As can be seen from table 1, the downlink transmission accounts for 40% to 90% of all the transmission time, and such setting of the uplink/downlink subframe ratio mainly takes into consideration the characteristic that the downlink data service is usually more than the uplink data service in the present multimedia service.

In the existing LTE technology, a network side informs all User Equipments (UEs) in a cell of what TDD uplink/downlink configuration the cell uses through a broadcast System message (SI, System Information). How to select the TDD uplink/downlink configuration is a problem for implementing inside the network, which may involve long-term statistical data of operators, the amount of current uplink/downlink pending traffic data known by the network side, and other strategic factors. In order to further reduce transmission delay, save UE energy, increase system throughput, and improve network performance, a method for dynamically changing TDD uplink/downlink configuration is proposed, which is expected to make TDD uplink/downlink configuration change in real time along with traffic, so as to maximize the advantage of TDD system in flexibly configuring uplink/downlink subframe ratio. The currently adopted Buffer Status Reporting (Buffer Status Reporting) mechanism is a Reporting mechanism based on the priority of a logical channel, which results in that a network side cannot timely and accurately know the uplink data amount in the UE, and thus unreasonable TDD uplink/downlink configuration may be adopted.

Disclosure of Invention

The technical problem to be solved by the present invention is to provide a buffer status reporting method and a terminal device, so as to solve the problem that the timeliness and accuracy of obtaining the uplink data volume at the network side are poor due to the existing buffer status reporting mode.

In order to solve the above technical problem, the present invention provides a buffer status reporting method, wherein when new uplink pending transmission data arrives in a Radio Link Control (RLC) entity or a Packet Data Convergence Protocol (PDCP) entity of a terminal device and a condition of a conventional Buffer Status Report (BSR) and a periodic Buffer Status Report (BSR) is not satisfied, a new buffer status report for indicating uplink buffer data volume information of the terminal device is triggered; or, triggering a conventional BSR when new uplink data to be transmitted arrives in a Radio Link Control (RLC) entity or a Packet Data Convergence Protocol (PDCP) entity of the terminal device; or setting the duration of the BSR retransmission timer to be less than or equal to the minimum period of the time division duplex configuration of the time division duplex long term evolution system.

Further, the method can also have the following characteristics:

when new uplink data to be transmitted in a Radio Link Control (RLC) entity or a Packet Data Convergence Protocol (PDCP) entity of the terminal device arrives and the conditions of a conventional Buffer Status Report (BSR) and a periodic Buffer Status Report (BSR) are not satisfied, and it is further determined that the number of padding bits for padding the BSR is smaller than the size of the long BSR plus a subheader thereof, a new buffer status report for indicating uplink buffer data volume information of the terminal device is triggered.

Further, the method can also have the following characteristics:

the uplink buffer data volume information refers to the data volume of all uplink to-be-transmitted data in the uplink buffer after transmission of the transmission time interval, or the data volume of the new uplink to-be-transmitted data after transmission of the transmission time interval.

Further, the method can also have the following characteristics:

the new buffer status report is carried by a media intervention control (MAC) element (CE).

Further, the method can also have the following characteristics:

the region identifier field of the MAC subheader of the MAC sub-header carrying the new buffer status report is represented by one of the values 01011 to 11000.

Further, the method can also have the following characteristics:

and after the terminal equipment sends the new buffer state report, starting or restarting a retransmission BSR timer and a periodic BSR timer.

In order to solve the technical problem, the invention also provides terminal equipment, which comprises a buffer status reporting optimization processing module; the buffer status reporting optimization processing module is configured to trigger a new buffer status report for indicating uplink buffer data volume information of the terminal device when new uplink data to be transmitted arrives in a Radio Link Control (RLC) entity or a Packet Data Convergence Protocol (PDCP) entity of the terminal device and a condition of a conventional Buffer Status Report (BSR) and a periodic Buffer Status Report (BSR) is not satisfied; or, the BSR is configured to trigger a conventional BSR when new uplink pending data arrives in a Radio Link Control (RLC) entity or a Packet Data Convergence Protocol (PDCP) entity of the terminal device; or the duration for setting the BSR retransmission timer is less than or equal to the minimum period of the tdd configuration of the tdd lte system.

Further, the terminal device may further have the following characteristics:

the buffer status reporting optimization processing module is further configured to trigger a new buffer status report for indicating uplink buffer data volume information of the terminal device when it is further determined that the number of padding bits for padding a Buffer Status Report (BSR) is smaller than the size of the long BSR plus a subheader thereof when new uplink pending data arrives in a Radio Link Control (RLC) entity or a Packet Data Convergence Protocol (PDCP) entity and the conditions of a conventional Buffer Status Report (BSR) and a periodic Buffer Status Report (BSR) are not satisfied.

Further, the terminal device may further have the following characteristics:

and the buffer status reporting optimization processing module is further configured to start or restart the retransmission BSR timer and the periodic BSR timer after the terminal device sends the new buffer status report.

The improved buffer status reporting method provided by the scheme can improve the timeliness and the accuracy of the network side for acquiring the uplink data volume, so that the network side can timely know the real data volume condition of the terminal equipment, and the occurrence of signaling overload is avoided.

Drawings

Fig. 1 is a schematic diagram of one way of triggering a conventional BSR;

fig. 2 is a schematic diagram of a second way of triggering a regular BSR;

fig. 3 is a schematic diagram of a buffer status reporting method;

fig. 4 is a schematic diagram illustrating a buffer status reporting method in a first embodiment;

fig. 5 is a schematic diagram of a buffer status reporting method in a second embodiment.

Detailed Description

In a cellular network, generally, both uplink resources and downlink resources are scheduled by a network side in a unified manner, and downlink data is sent to a UE from the network side, so the network side knows the data amount of the downlink data, but uplink data is sent to the network side from the UE side, and if the UE does not know the network side, the network side cannot know the data amount of the uplink data and the time of arrival of the uplink data, and cannot configure appropriate uplink resources for the UE to send the uplink data. In LTE, through a buffer status reporting mechanism, UE informs a network side how much uplink data is currently to be sent, and assists the network side in allocating uplink resources. In the LTE technology, a network side needs to maintain priorities between different UEs in a cell and also maintains priorities of different logical channels inside each UE, so the BSR mechanism of LTE is based on logical channel priorities.

The network side configures two timers for the UE through RRC (Radio Resource Control) signaling: a retransmission BSR Timer (retxsbsr-Timer) and a periodic BSR Timer (periodicBSR-Timer).

There are three BSR modes: regular BSR (Regular BSR), Periodic BSR (Periodic BSR) and padding BSR (padding BSR).

When new uplink data becomes uplink data to be transmitted in an RLC entity or a PDCP entity of the UE and the priority of a logical channel to which the new uplink data to be transmitted belongs is higher than that of a logical channel in which the uplink data to be transmitted is stored in a buffer before or the uplink data to be transmitted does not exist in the current buffer, the conventional BSR is triggered. For example, as shown in fig. 1, a schematic diagram of triggering a Regular BSR is shown, where 101 is an uplink buffer, where data to be transmitted of all uplink Logical Channels (LCs) are stored, the data to be transmitted of LC2 and LC3 are stored in the buffer 101, and the priority of LC1 is higher than that of LC2, the priority of LC2 is higher than that of LC3, and a new data arrives at the current LC1, which will trigger the Regular BSR. Fig. 2 is a schematic diagram of a second triggering Regular BSR, where 201 is an uplink buffer, in which pending data of all uplink logical channels are stored, and the priority of LC1 is higher than that of LC2, and the priority of LC2 is higher than that of LC 3. There is no pending data in the previous buffer, and the LC3 currently has newly arrived pending data, and since there is no pending data in the buffer, the RegularBSR is triggered. The third case of triggering the Regular BSR is when the retransmission BSR timer times out and the UE has uplink data to transmit, which will also trigger the Regular BSR.

For the other two BSRs, the Periodic BSR and the Padding BSR. The triggering condition of Periodic BSR is that the Periodic BSR timer is overtime, while the triggering condition of Padding BSR is that no Regular BSR or Periodic BSR is contained in a MAC protocol data Unit (MAC PDU) created by the MAC layer in the current Transmission Time Interval (TTI), and a Padding bit (Padding bit) therein is greater than or equal to one BSR MAC ce plus the size of its MAC subheader, which will trigger the Padding BSR. The reason for the above setting is that the padding bits do not have any information amount, and the BSR is placed therein to reduce resource waste.

For a MAC PDU created by the MAC layer, only one BSR can be carried, for example, when not only a regular BSR is triggered for a certain TTI, but also a Periodic BSR is triggered, only one BSR can be sent. As can be seen from fig. 1, if the priority of the logical channel LC1 where new pending data currently arrives is the same as LC2 or LC3, or the priority is lower than any of LC2 and LC3, reporting of Regular BSR is not triggered, in order to reduce signaling transmission over the air interface, the network usually does not set the values of the periodic BSR timer and the retransmission BSR timer too small, and the padding bits are usually not too many, and are usually only enough to report the pending data amount of one logical channel group, which is inevitably the logical channel group with the highest priority. The BSR reporting mechanism described above is disadvantageous for methods that wish to improve network performance by dynamically adjusting TDD configurations.

As shown in fig. 3, the method for reporting a buffer status provided by the present solution includes: when new uplink data to be transmitted in a Radio Link Control (RLC) entity or a Packet Data Convergence Protocol (PDCP) entity of terminal equipment arrives and the conditions of a conventional Buffer Status Report (BSR) and a periodic Buffer Status Report (BSR) are not met, triggering a new buffer status report for indicating uplink buffer data volume information of the terminal equipment;

or, triggering a conventional BSR when new uplink data to be transmitted arrives in a Radio Link Control (RLC) entity or a Packet Data Convergence Protocol (PDCP) entity of the terminal device;

or setting the duration of the BSR retransmission timer to be less than or equal to the minimum period of the time division duplex configuration of the time division duplex long term evolution system.

The new buffer status report is carried by a Media Access Control (MAC) element (CE), the size of the MAC CE carrying the new buffer status report is one byte, and a region identifier field of a MAC subheader of the new buffer status report is represented by one value in binary 01011 to 11000.

And when the UE does not currently have uplink resources to send the new buffer state report, triggering a Scheduling Request (Scheduling Request) sending process.

The terminal device corresponding to the method includes a buffer status reporting optimization processing module, and the module executes the corresponding execution mode described in the method, which is not described herein again.

The present solution is explained in detail below by means of specific examples.

Detailed description of the preferred embodiment

Fig. 4 is a schematic flow diagram of a specific embodiment.

S401: new upstream pending data arrives.

When the RLC entity or the PDCP entity of the UE has uplink data to become data to be transmitted, the situation is indicated that new uplink data to be transmitted arrives.

For the RLC entity, RLC Service Data Units (SDUs) or segments thereof that have not yet been assembled into RLC data PDUs; RLC data PDUs waiting for retransmission and STATUS PDUs (STATUS PDUs) triggered to need to be transmitted at the next transmission occasion or a part thereof are considered to be pending data of the RLC layer.

For the PDCP entity, PDCP SDUs that have not been processed by the PDCP layer or PDCP PDUs that have been processed by the PDCP layer but have not been submitted to the lower layer; or in lossless handover, the PDCP PDUs or PDCP PDUs which are submitted to the lower layer but have not received the successful transmission confirmation are considered as the pending data of the PDCP layer.

And when uplink data in the UE becomes the data to be transmitted of the RLC layer or the PDCP layer, indicating that new uplink data to be transmitted arrives.

S402: the MAC CE that generates the uplink buffer data amount information for indicating the UE is referred to as a new data arrival MAC CE.

The size of the new data arriving at the MAC CE is one byte, wherein the carried content is the data volume of all uplink to-be-transmitted data in the uplink cache after transmission of the transmission time interval, or the data volume of the new uplink to-be-transmitted data after transmission of the transmission time interval. If the content is the former, the content needs to indicate the size of the data volume in the cache after the transmission of the TTI; if the content is the latter, it needs to indicate the size of the newly arrived data amount after the TTI transmission. Since there may be more uplink resources allocated by the network side, a part of newly arriving data may also be transmitted.

The 8 bits of new data arriving in the MAC CE may represent 512 levels of 0 to 511, the buffer size level corresponding to the original BSR in the protocol 36.321 may be adopted, the original mapping table may be expanded for use, the data amount may be divided in addition to 64 levels of the original table, or a new mapping table may be designated. The arrival of the new data in the LCID field of the MAC subheader of the report MAC ce is represented by a value in binary 01011 to 11000.

If the uplink resources divided by the TTI are enough to accommodate all uplink data to be transmitted, including newly arrived data to be transmitted, the MAC CE does not need to be generated, the buffer status report does not need to be performed, the subsequent steps do not need to be executed continuously, and the process is ended.

S403: and judging whether the triggering condition of the Regular BSR or the Periodic BSR is met, if so, executing the step S404, otherwise, executing the step S40.

S404: triggering a Regular BSR or a Periodic BSR, deleting new data to reach the MAC CE, and ending the process.

S405: and judging whether the trigger condition of the Padding BSR is met, if so, executing the step S406, otherwise, executing the step S408.

S406: and judging whether the number of the padding bits is larger than or equal to the long BSR plus the size of the subheader, if so, executing the step S407, otherwise, executing the step S408.

S407: and deleting the padding BSR and transmitting new data to the MAC CE.

At this time, the number of Padding bits is smaller than the long BSR plus the size of the subheader, so that if the transmitted PaddingBSR is necessarily a Short BSR (Short BSR) or a Truncated BSR (Truncated BSR), only the amount of data to be transmitted of a logical channel with higher priority in the uplink buffer can be represented, and the current real uplink buffer condition is not represented enough, so that the related data of the PaddingBSR is deleted at this time, new data is transmitted to the MAC CE at the original position where the PaddingBSR is to be transmitted, and the process is ended.

S408, new data is transmitted to the MAC CE.

And if the Padding BSR is not triggered at this time, it indicates that the uplink vacant resource is less than 8 bits, at this time, a process of transmitting the SR is initiated, the uplink resource is requested to the network side, and new data is transmitted to the MAC CE after the network allocates the uplink resource. New data may arrive at the MAC CE while waiting for transmission, and the new data with the latest transmission arrival time arrives at the MAC CE during transmission, and the process ends.

Detailed description of the invention

The second specific embodiment is different from the first specific embodiment in that new data arriving at the MAC CE is generated after new uplink pending data arrives, but new data arriving at the MAC CE is generated after a new buffer status report is determined.

Fig. 5 is a schematic flow diagram of a specific embodiment.

S501: the new uplink data to be transmitted arrives, which is the same as step 401 and is not described again.

S502: and judging whether the triggering condition of the Regular BSR or the Periodic BSR is met, if so, executing step S503, otherwise, executing step S504.

S503: triggering a Regular BSR or a Periodic BSR, and ending the process.

S504: and judging whether the trigger condition of the Padding BSR is met, if so, executing the step S505, otherwise, executing the step S507.

S505: and judging whether the number of the padding bits is larger than or equal to the long BSR plus the size of the subheader, if so, executing the step S506, otherwise, executing the step S507.

S506: and triggering the padding BSR, and ending the process.

S507: and the MAC CE generating the uplink buffer data volume information for indicating the UE is called as new data to arrive at the MAC CE and transmit, and the flow is ended.

Detailed description of the preferred embodiment

When new uplink data to be transmitted in the UE arrives, that is, when the uplink data in the UE becomes the RLC layer or PDCP layer data to be transmitted, the reporting procedure of the Regular BSR is triggered. If the periodic BSR is triggered while the regular BSR is triggered, the UE determines which BSR to send. The essence of this embodiment is to modify the condition for triggering the Regular BSR to achieve the purpose of informing the network side that the uplink buffer of the UE is really the data volume.

Detailed description of the invention

In the prior art, if the BSR timer expires and data to be transmitted in any logical channel of the UE is to be transmitted, a regular BSR is triggered, but in the existing LTE system, the minimum value of the BSR timer is 320 milliseconds (ms), and if the TDD configuration change period of the TD-LTE is 10ms, the regular BSR triggered by the BSR timer expiring is not sufficient to adapt to the fast TDD configuration change period. Therefore, the time length for setting the BSR retransmission timer is less than or equal to the minimum period of TDD configuration change of the TD-LTE system, and the network side can be ensured to obtain the real cache condition in the UE in time.

It should be noted that the embodiments and features of the embodiments in the present application may be arbitrarily combined with each other without conflict.

The present invention is capable of other embodiments, and various changes and modifications may be made by one skilled in the art without departing from the spirit and scope of the invention.

It will be understood by those skilled in the art that all or part of the steps of the above methods may be implemented by instructing the relevant hardware through a program, and the program may be stored in a computer readable storage medium, such as a read-only memory, a magnetic or optical disk, and the like. Alternatively, all or part of the steps of the above embodiments may be implemented using one or more integrated circuits. Accordingly, each module/unit in the above embodiments may be implemented in the form of hardware, and may also be implemented in the form of a software functional module. The present invention is not limited to any specific form of combination of hardware and software.

Claims

1. A method for reporting buffer status, wherein,

when new uplink data to be transmitted in a Radio Link Control (RLC) entity or a Packet Data Convergence Protocol (PDCP) entity of the terminal equipment arrives and the conditions of a conventional Buffer Status Report (BSR) and a periodic Buffer Status Report (BSR) are not met, triggering a new buffer status report for indicating uplink buffer data volume information of the terminal equipment;

when new uplink data to be transmitted in a Radio Link Control (RLC) entity or a Packet Data Convergence Protocol (PDCP) entity of the terminal equipment arrives and the conditions of a conventional Buffer Status Report (BSR) and a periodic Buffer Status Report (BSR) are not met, and when the number of filling bits filling the BSR is further judged to be smaller than the number of the long BSR plus the subheader, triggering a new buffer status report for indicating uplink buffer data volume information of the terminal equipment.

2. The method of claim 1, wherein,

3. The method of claim 1 or 2,

the new buffer status report is carried by a media intervention control, MAC, element, CE.

4. The method of claim 3, wherein,

5. The method of claim 1 or 2,

6. A terminal device comprises a buffer status reporting optimization processing module; wherein,

the buffer status reporting optimization processing module is configured to trigger a new buffer status report for indicating uplink buffer data volume information of the terminal device when new uplink to-be-transmitted data arrives in a radio link control RLC entity or a packet data convergence protocol PDCP entity of the terminal device and a condition of a conventional buffer status report BSR and a periodic buffer status report BSR is not satisfied;

and the buffer status reporting optimization processing module is further configured to trigger a new buffer status report for indicating uplink buffer data volume information of the terminal device when the number of padding bits of the padding BSR is further judged to be smaller than the long BSR plus the subheader thereof when new uplink to-be-transmitted data arrives in the radio link control RLC entity or the packet data convergence protocol PDCP entity and the conditions of the regular buffer status report BSR and the periodic buffer status report BSR are not satisfied.

7. The terminal device of claim 6,

8. The terminal device of claim 6 or 7,