CN101170388B

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Info

Publication number: CN101170388B
Application number: CN2006101498378A
Authority: CN
Inventors: 张健
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2006-10-27
Filing date: 2006-10-27
Publication date: 2011-01-19
Anticipated expiration: 2026-10-27
Also published as: CN101170388A

Abstract

The invention discloses a method capable of defining whether re-subsection is required to retransmit a wireless link control layer protocol data unit. A media access control layer scheduling entity calculates the optional size of a transmission block when being retransmitted, and judges whether the calculated transmission block size is larger than that of a first-time protocol data unit or not. If larger, then the calculated transmission block size is chosen as the retransmission transmission block size; if not, then the scheduling entity adjusts the wireless resource used for retransmission in accordance with the distribution condition of the current wireless resource. If the adjusted wireless resource can not meet the first-time protocol data unit size, then the re-subsection is judged to be carried out. The scheduling strategy reduces the subsection/series connection/re-subsection processing overhead of the RLCPDU first-time transmission and retransmission, which enhances the system performance.

Description

The method of segmentation whether heavily when determining that protocol Data Unit retransmits

Technical field

The present invention relates to packet service scheduling technology in the wireless communication field, relate in particular to protocol Data Unit that a kind of selection is used for the method for the first transport block size that passes of protocol Data Unit of wireless chain control layer and the definite wireless chain control layer method of segmentation whether heavily when retransmitting.

Background technology

In the wireless access network of 3G (Third Generation) Moblie long evolving system, automatically repeat requests entity A RQ (Automatic Repeat reQuest) is positioned at the wireless chain control layer RLC (Radio Link Control) of base station, TPDU RLC PDU (ProtocolData Unit).Mix the media access control layer MAC (Media Access Control) that automatic repeat requests entity HARQ (Hybrid Automatic RepeatreQuest) is positioned at the base station, the protocol Data Unit MAC PDU that transmission MAC layer is generated is transmission block TB (Transfer Block).RLC PDU carries out generating behind segmentation/serial connection/(or filling) processing and the additional corresponding rlc layer header according to the determined transmission block TB of MAC layer scheduling result size for the service data unit RLC SDU (Service Data Unit) from the upper-layer protocol layer.RLC PDU is called MAC SDU after sending to the MAC layer, generates MAC PDU after the MAC layer is again through multiplexing/serial connection/segment processing and additional corresponding M AC layer header.The wireless chain control layer and the media access control layer of the HSPA of 3-G (Generation Three mobile communication system) (High Speed PacketAccess) evolution system also may all be positioned at the base station, therefore also may adopt similar scheme to generate RLC PDU and MAC PDU.

After the RLC of wireless chain control layer SDU length adds rlc layer header overhead and MAC layer header overhead,, need carry out segment processing to RLC SDU if during greater than the selected transmission block TB of media access control layer size; If when also having other RLC SDU in media access control layer selected transmission block TB size and the buffering area, can be connected in series processing to these RLC SDU.But,, also can bring certain drawback if only RLC SDU is carried out segmentation/serial connection according to transmission block TB size.If wireless environment is fine, the selected transmission block TB of MAC layer scheduling entity size is very big, RLC will be very big according to the RLC PDU size that this TB size segmentation is generated, when media access control layer HARQ error of transmission needs the ARQ of wireless chain control layer to retransmit, may cause two kinds of consequences: (1) ARQ need transmit bigger RLC PDU when retransmitting, and has wasted Radio Resource; (2) if wireless environment variation when retransmitting, can't transmit initial RLCPDU, then need carry out heavily segmentation to RLC PDU, increase processing expenditure and header overhead, and the probability of heavily segmentation takes place when retransmitting and is greater than less RLC PDU in bigger RLC PDU at rlc layer or MAC layer.And weigh the problem that can't transmit Initial R LC PDU when fragmentation feature can only solve the ARQ re-transmission, owing to still needing to transmit the full content of whole RLC PDU, so can't solve the waste of radio resources problem.

But, if scheduling entity is not considered RLC PDU size threshold when distributing radio resource, then selected transmission block TB size is bigger greater than the probability of RLCPDU size threshold when wireless environment is better, so it is bigger according to the probability that RLC PDU size threshold generates RLC PDU at rlc layer, can cause like this carrying out multiplexing or increasing filler, increase MAC layer processing expenditure and header overhead to reach the TB size at the MAC layer.When retransmitting, if wireless environment variation, if scheduling entity is not considered the size of initial transmission piece, then need carry out heavily segmentation or bigger to the probability that initial MAC PDU carries out heavily segmentation to Initial R LC PDU, can increase the processing expenditure and the header overhead of heavily segmentation equally at rlc layer at the MAC layer.

Therefore, need a kind of packet service scheduling strategy, can be used for addressing the above problem.

Summary of the invention

The method of segmentation whether heavily when the method for the first transport block size that passes of the protocol Data Unit that main purpose of the present invention is to provide a kind of selection to be used for wireless chain control layer and the protocol Data Unit of definite wireless chain control layer retransmit, be used to reduce the segmentation/serial connection/weight segment processing expense when RLC PDU is first to be passed and retransmit, improve systematic function.

To achieve these goals, according to a first aspect of the invention, the invention provides the method that a kind of selection is used for the first transport block size that passes of protocol Data Unit of wireless chain control layer.Method may further comprise the steps:

Step S102, optional transport block size when the scheduling entity of media access control layer is calculated first the biography;

Whether step S104 judges the transport block size that is calculated greater than the protocol Data Unit dimension threshold, if be not more than, the transport block size conduct of then selecting to be calculated is used for the first transport block size that passes, if greater than, then proceed to step S106;

Step S106, scheduling entity is according to the distribution condition of current wireless resource, whether judgement selects the transport block size greater than the protocol Data Unit dimension threshold, if, the transport block size of then selecting to be calculated is as being used for the first transport block size that passes, if not, then selecting the transport block size less than the protocol Data Unit dimension threshold is to be used for the first transport block size that passes.

In step S106, if the user has the business on other higher priority radio bearers, then the scheduling entity judgement to the high-priority service on other radio bearers, is selected the transport block size less than the protocol Data Unit dimension threshold with allocation of radio resources.

In step S106, if there is the customer service of other higher priority to need scheduling, then the scheduling entity judgement is given other high-priority users business with allocation of radio resources, selects the transport block size less than the protocol Data Unit dimension threshold.

In step S106, if the user does not have the business on other higher priority radio bearers, but the business on the lower priority radio bearer that the long period do not obtain dispatching is arranged, then the business on scheduling entity judgement the lower priority radio bearer that allocation of radio resources was not obtained dispatching to the long period is selected the transport block size less than the protocol Data Unit dimension threshold.

In step S106, if the channel quality indication situation that scheduling entity is reported according to relevant user equipment knows that the channel quality of this customer service is higher than the channel quality of other customer services, selection less than the transport block size of protocol Data Unit dimension threshold allocation of radio resources give other customer service can cause wireless resource utility efficiency low, reduce entire system throughput and performance, then judgement does not force to select the transport block size less than the protocol Data Unit threshold size.

To achieve these goals, according to a second aspect of the invention, the method for segmentation whether heavily when the protocol Data Unit that the invention provides a kind of definite wireless chain control layer retransmits.Method may further comprise the steps:

Step S202, the scheduling entity of media access control layer is calculated optional transport block size when retransmitting;

Step S204 judges protocol Data Unit size when whether the transport block size calculated passes greater than head, if greater than, the transport block size of then selecting to be calculated if be not more than, then proceeds to step S206 as the transport block size that is used to retransmit;

Step S206, the Radio Resource that scheduling entity can be used for retransmitting according to the distribution condition adjustment of current wireless resource, if protocol Data Unit size when the Radio Resource of being adjusted does not satisfy first the biography, then heavily segmentation is carried out in judgement.

Alternatively, in step S206, adjust to be included as to retransmit and distribute how continuous or discrete subcarrier, to obtain frequency diversity gain.

Alternatively, in step S206, adjust to be included as to retransmit and distribute more than transmitting employed Transmission Time Interval number last time, with the acquisition time diversity gain.

Alternatively, in step S206, adjust and to be included in protocol Data Unit when being the insensitive non-real-time service of time delay, postpone its scheduling, when assignable Radio Resource can satisfy, dispatches again in several Transmission Time Intervals in the back.

Alternatively, in step S206, adjust the priority that comprises that raising retransmits, to obtain than other lower-priority subscriber's more resources.

To achieve these goals, according to a third aspect of the invention we, the invention provides the method that a kind of selection is used for the first transport block size that passes of protocol Data Unit of wireless chain control layer.Optional transport block size when the scheduling entity of media access control layer is calculated first the biography: according to the distribution condition of current wireless resource, whether judgement selects the transport block size less than the protocol Data Unit dimension threshold.

If the user has the business on other higher priority radio bearers, then the scheduling entity judgement to the high-priority service on other radio bearers, is selected the transport block size less than the protocol Data Unit dimension threshold with allocation of radio resources.

If there is the customer service of other higher priority to need scheduling, then the scheduling entity judgement is given other high-priority users business with allocation of radio resources, selects the transport block size less than the protocol Data Unit dimension threshold.

If the user does not have the business on other higher priority radio bearers, but the business on the lower priority radio bearer that the long period do not obtain dispatching is arranged, then the business on scheduling entity judgement the lower priority radio bearer that allocation of radio resources was not obtained dispatching to the long period is selected the transport block size less than the protocol Data Unit dimension threshold.

If the channel quality indication situation that scheduling entity is reported according to relevant user equipment knows that the channel quality of this customer service is higher than the channel quality of other customer services, selection less than the transport block size of protocol Data Unit dimension threshold allocation of radio resources give other customer service can cause wireless resource utility efficiency low, reduce entire system throughput and performance, then judgement does not force to select the transport block size less than the protocol Data Unit threshold size.

To achieve these goals, according to a forth aspect of the invention, the method for segmentation whether heavily when the protocol Data Unit that the invention provides a kind of definite wireless chain control layer retransmits.The scheduling entity of media access control layer is calculated optional transport block size when retransmitting: scheduling entity is wirelessly regulated the strategy decision and whether is selected transport block size more than or equal to the protocol Data Unit initial value according to corresponding, wherein the protocol Data Unit initial value equals transport block size after adding the media access control layer header overhead, if protocol Data Unit size when the Radio Resource of being adjusted does not satisfy first the biography, then heavily segmentation is carried out in judgement.

Alternatively, adjust to be included as to retransmit and distribute how continuous or discrete subcarrier, to obtain frequency diversity gain.

Alternatively, adjustment is included as to retransmit and distributes more than transmitting employed Transmission Time Interval number last time, with the acquisition time diversity gain.

Alternatively, adjust and to be included in protocol Data Unit when being the insensitive non-real-time service of time delay, postpone its scheduling, when assignable Radio Resource can satisfy, dispatches again in several Transmission Time Intervals in the back.

Alternatively, adjust the priority that comprises that raising retransmits, to obtain than other lower-priority subscriber's more resources.

By technique scheme, scheduling strategy disclosed by the invention has reduced the segmentation/serial connection/weight segment processing expense when RLC PDU is first to be passed and retransmit, and has improved systematic function.

Description of drawings

Accompanying drawing described herein is used to provide further understanding of the present invention, constitutes the application's a part, and illustrative examples of the present invention and explanation thereof are used to explain the present invention, do not constitute improper qualification of the present invention.In the accompanying drawings:

Fig. 1 is the flow chart of the method for the selection according to the present invention first transport block size that passes of protocol Data Unit that is used for wireless chain control layer;

Whether heavily Fig. 2 is the flow chart of the method for segmentation when retransmitting according to the protocol Data Unit of definite wireless chain control layer of the present invention;

Fig. 3 is the schematic diagram according to the system configuration of the embodiment of the invention;

Fig. 4 is the process chart according to first embodiment of the invention; And

Fig. 5 is the process chart according to second embodiment of the invention.

Embodiment

Describe the present invention below with reference to the accompanying drawings in detail.

With reference to Fig. 1, the method that selection according to the present invention is used for the first transport block size that passes of protocol Data Unit of wireless chain control layer may further comprise the steps:

Alternatively, in step S106, if the channel quality indication situation that scheduling entity is reported according to relevant user equipment knows that the channel quality of this customer service is higher than the channel quality of other customer services, selection less than the transport block size of protocol Data Unit dimension threshold allocation of radio resources give other customer service can cause wireless resource utility efficiency low, reduce entire system throughput and performance, then judgement does not force to select the transport block size less than the protocol Data Unit threshold size.

With reference to Fig. 2, when retransmitting according to the protocol Data Unit of definite wireless chain control layer of the present invention whether heavily the method for segmentation may further comprise the steps:

The present invention relates to the digital mobile communication technical field, particularly packet service scheduling method in the wireless communication system.

The factor of existing dispatching algorithm distributing radio resource time institute foundation mainly comprises quality QoS demand, measurement report, buffer state, untreated re-transmission still, channel quality indicator (CQI) (Channel Quality Indicator), UE ability, UE dormancy period and measurement clearance, system parameters such as bandwidth/interference rank or jamming pattern etc.Scheduling strategy of the present invention has increased in that RLC PDU is first when passing with RLC PDU size threshold as a kind of Consideration wherein, when RLC PDU retransmits with initial transmission piece TB size as a kind of Consideration wherein.

Main contents of the present invention are:

1. whether need to select method when utilizing scheduling entity to determine that RLC PDU is first to pass greater than the transmission block TB size of RLCPDU threshold value.

2. utilize scheduling entity to determine whether RLC PDU needs the method for heavily segmentation when retransmitting.

Treatment step of the present invention is:

Step 1: whether need to select method when utilizing scheduling entity to determine that RLC PDU is first to pass greater than the transmission block TB size of RLC PDU threshold value.Scheduling when the resource allocation RLC PDU size threshold as one of scheduling decision factor, RLCPDU for the head biography, scheduling entity is selected transmission block TB size less than RLC PDU size threshold according to certain strategy and algorithm as far as possible in the scope that can regulate, thereby avoid carrying out multiplexing or increasing filler reaching the overhead that the TB size is brought at the MAC layer, adjustable range refers to that the scheduling adjustment expense is less than carry out scope multiplexing or when increasing the filler expense at the MAC layer.

Further, radio condition is better when the first biography of RLC PDU, the scheduling medium access control layer entity can be for the service selection on this user's present wireless bearing RB during greater than the transmission block TB size of RLCPDU size threshold, and scheduling entity can adopt following strategy adjustment to distribute to the Radio Resource of the first RLC PDU that passes:

1) if this user has the business on other higher priority radio bearer RB, perhaps there is the customer service of other higher priority to need scheduling, can give the high-priority service on other RB of this user allocation of radio resources or distribute to other high-priority users, thereby to the transmission block TB size of the service selection on the current RB less than RLC PDU size threshold;

2), also can give business on the lower priority RB that this user's long period do not obtain dispatching resource allocation if this user does not have the business on other higher priority RB.

When adopting said method, according to the channel quality indicator (CQI) situation that relevant user equipment is reported, scheduling entity need be avoided giving the very poor user of channel quality allocation of radio resources.When this user's channel quality fine, and the channel quality of other high-priority users is relatively poor, if select less than the transmission block TB size of RLC PDU threshold value size allocation of radio resources give other user can cause wireless resource utility efficiency low, reduce under the situation of entire system throughput and performance, then be the suitable transmission block TB size of service selection on this RB of this user, do not force to select transmission block TB size less than RLC PDU threshold value size.

Step 2: utilize scheduling entity to determine whether RLC PDU needs the method for heavily segmentation when retransmitting.The initial length of the RLC PDU that when scheduling and resource allocation need is retransmitted is as one of scheduling decision factor, RLC PDU for the needs re-transmission, scheduling entity satisfies Radio Resource required when retransmitting according to certain strategy and algorithm as far as possible in the scope that can regulate, thereby avoid at rlc layer to heavily segmentation or of RLC PDU the scope when adjustable range refers to the scheduling adjustment expense less than heavy fragmentation overhead at the MAC layer overhead that heavily segmentation is brought to MAC PDU.

Further, radio condition is relatively poor when retransmitting RLC PDU, and when the scheduling medium access control layer entity possibly can't be selected initial transmission piece TB size, scheduling entity can adopt following strategy adjustment to distribute to the Radio Resource of the RLC PDU that is retransmitted:

1) the channel quality indicator (CQI) situation of being reported according to relevant user equipment UE can be distributed how continuous or discrete subcarrier for this RLC PDU, to obtain frequency diversity gain; But need avoid under the very poor situation of channel quality to it distributes more subcarrier, this can reduce other channel quality performance of user preferably, thereby reduces overall system performance;

When 2) adopting asynchronous HARQ, can distribute more than transmitting employed TTI (Transmission Time Interval, Transmission Time Interval) number last time, with the acquisition time diversity gain for this RLC PDU; But need avoid under the very poor situation of channel quality to it distributes more TTI, this can reduce other channel quality performance of user preferably, thereby reduces overall system performance;

3) if this RLC PDU belongs to the insensitive non-real-time service of time delay, can under the service quality QoS condition that allows, postpone its scheduling, when can satisfying, dispatches again assignable Radio Resource in several TTI in the back;

4) improve the priority of the RLC PDU of required re-transmission, thereby can obtain than other lower-priority subscriber's more resources.

If scheduling entity in adjustable extent all the adjusting factors that can utilize all can't satisfy when retransmitting the required Radio Resource of this RLC PDU, it is weighed segment processing; For example the channel quality conditions reported of relevant user equipment is very poor, retransmits resource requirement if utilize scheduling to satisfy by force, may cause retransmitting failure, and reduce power system capacity and throughput, may reduce systematic function largely.

Fig. 3 illustrates the system configuration that comprises the entity relevant with the present invention, and the base station user face protocol stack comprises physical layer, media access control layer, wireless chain control layer.Wherein the ARQ entity is positioned at wireless chain control layer, and scheduling entity and HARQ entity are positioned at media access control layer.

Fig. 4 illustrates the first embodiment of the present invention.

Step 10:MAC layer scheduling entity is according to set dispatching algorithm primary Calculation transmission block TB size;

Step 20: transmission block TB size＞RLC PDU length threshold value? if be not more than, changestep 30; If greater than, changestep 40;

Step 30:MAC layer scheduling entity judged does not need the corrected Calculation result, notifies rlc layer as the foundation to RLC SDU segmentation/serial connection transmission block TB size;Change step 60;

Step 40: thus judge whether to give the business on other RB of this user allocation of radio resources or to distribute to other user to be the transmission block TB size of the service selection on the current RB according to set strategy less than RLC PDU size threshold? if not, changestep 30; Ifchange step 50;

Step 50: scheduling entity is adjusted allocation of radio resources, recomputates transmission block TB size, selects the transmission block TB size less than RLC PDU length threshold value;Change step 30;

Is step 60:RLC layer ARQ entity received the message of RLC PDU bust this? if not, changestep 10; Ifchange step 70;

Step 70: need to retransmit this RLC PDU, MAC layer scheduling entity calculated the transmission block TB size that can select when retransmitting;Change step 80;

Step 80: the RLC PDU size of transmission block TB size＜initial transmission? if be not less than, changestep 30; If less than, changestep 90; Illustrate that under situation about being not less than, the RLC PDU of this re-transmission sends to the MAC layer and is called MAC SDU, can be multiplexing at MAC layer and other MAC SDU;

Step 90: judge whether to adjust allocation of radio resources according to set strategy, satisfy the transmission block TB size of Initial R LC PDU size with selection to the more Radio Resource of traffic assignments on the current RB? if not, changestep 30; Ifchange step 100;

Step 100: scheduling entity is adjusted allocation of radio resources, recomputates transmission block TB size, selects to equal the transmission block TB size of Initial R LC PDU length;Change step 30.

Fig. 5 illustrates the second embodiment of the present invention.In this mode, scheduling entity does not need the process through correction algorithm.For the RLC PDU that head passes, whether direct decision selects the TB size less than RLC PDU threshold value according to corresponding factor; For the RLC PDU that retransmits, directly decision is to retransmit initial RLC PDU or heavily segmentation according to corresponding factor.

Step 10:MAC layer scheduling entity calculated transmission block TB size according to set dispatching algorithm: with RLC PDU threshold value is one of input parameter, and the MAC scheduling entity is wirelessly regulated the strategy decision and whether selected TB size less than corresponding RLC PDU threshold value according to corresponding;Change step 20;

Step 20:MAC layer scheduling entity notifies rlc layer as the foundation to RLC SDU segmentation/serial connection transmission block TB size;Change step 30;

Is step 30:RLC layer ARQ entity received the message of RLC PDU bust this? if not, changestep 10; Ifchange step 40;

Step 40: the RLC PDU that this need retransmit is scheduled, MAC layer scheduling entity calculated the transmission block TB size that can select when retransmitting: RLC PDU initial value was one of input parameter when head was passed, and the MAC scheduling entity is according to the corresponding wireless TB size (RLC PDU initial value equals the TB size after adding MAC layer header overhead) whether the strategy decision can select to equal RLC PDU initial value of regulating;Change step 50;

Step 50:MAC layer scheduling entity notifies rlc layer as the foundation to RLC SDU segmentation/serial connection transmission block TB size;Change step 10.

The above is the preferred embodiments of the present invention only, is not limited to the present invention, and for a person skilled in the art, the present invention can have various changes and variation.Within the spirit and principles in the present invention all, any modification of being done, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims

1. whether heavily the method for segmentation when the protocol Data Unit of a definite wireless chain control layer retransmits is characterized in that, may further comprise the steps:

Step S206, the Radio Resource that described scheduling entity can be used for retransmitting according to the distribution condition adjustment of current wireless resource, if protocol Data Unit size when the Radio Resource of being adjusted does not satisfy first the biography, then heavily segmentation is carried out in judgement.

2. method according to claim 1 is characterized in that, in step S206, described adjustment is included as to retransmit and distributes how continuous or discrete subcarrier, to obtain frequency diversity gain.

3. method according to claim 1 is characterized in that, in step S206, described adjustment is included as to retransmit and distributes more than transmitting employed Transmission Time Interval number last time, with the acquisition time diversity gain.

4. method according to claim 1, it is characterized in that, in step S206, described adjustment is included in described protocol Data Unit when being the insensitive non-real-time service of time delay, postpone its scheduling, when assignable Radio Resource can satisfy, dispatch again in several Transmission Time Intervals in the back.

5. method according to claim 1 is characterized in that, in step S206, described adjustment comprises the priority that improves re-transmission, to obtain than other lower-priority subscriber's more resources.

6. whether heavily the method for segmentation when the protocol Data Unit of a definite wireless chain control layer retransmits is characterized in that:

The scheduling entity of media access control layer is calculated optional transport block size when retransmitting: described scheduling entity is adjusted Radio Resource according to corresponding wireless adjusting strategy, whether decision selects the transport block size more than or equal to the protocol Data Unit initial value, wherein said protocol Data Unit initial value equals described transport block size after adding the media access control layer header overhead, protocol Data Unit size when passing headed by the described protocol Data Unit initial value; If protocol Data Unit size when the Radio Resource of being adjusted does not satisfy first the biography, then heavily segmentation is carried out in judgement.

7. method according to claim 6 is characterized in that, described adjustment is included as to retransmit and distributes how continuous or discrete subcarrier, to obtain frequency diversity gain.

8. method according to claim 6 is characterized in that, described adjustment is included as to retransmit and distributes more than transmitting employed Transmission Time Interval number last time, with the acquisition time diversity gain.

9. method according to claim 6, it is characterized in that, described adjustment is included in described protocol Data Unit when being the insensitive non-real-time service of time delay, postpones its scheduling, dispatches when assignable Radio Resource can satisfy in several Transmission Time Intervals in the back again.

10. method according to claim 6 is characterized in that, described adjustment comprises the priority that improves re-transmission, to obtain than other lower-priority subscriber's more resources.