CN101060474A - A service quality assurance-based grouping service wireless resource dispatching method - Google Patents

Abstract

The disclosed wireless resource scheduling method for grouping business based on QoS comprises: determining business PRI for resource scheduling; to different type user, allocating resource for user with average data rate less GBR; calculating PRI for every user according to current rate, average rate and overtime threshold or based on buffer ratio, and allocating resource as user PRI. This invention allocates resource more flexibly, and can adapt resource management in future.

Description

A kind of Packet Service scheduling method for wireless resource based on service quality guarantee

Technical field

The present invention relates to the mobile communication technology field, be specifically related to a kind of Packet Service scheduling method for wireless resource.

Background technology

It is the technology that a kind of raising Time Division-Synchronous Code Division Multiple Access inserts (TD-SCDMA) system descending message transmission rate that high speed downlink packet inserts (HSDPA), be that 3GPP standardization body proposes in order to satisfy in the system standard of the asymmetric demand of up-downgoing data service by R5 (Release 5) version, can under existing TD-SCDMA system network architecture, user's downlink service data speed be brought up to more than the 2.8Mbps.

Fig. 1 is the sub-district part configuration diagram of WCDMA or TD-SCDMA system.As shown in Figure 1, this system comprises radio network controller (RNC), base station and subscriber equipment (UE).The resource relevant with HSDPA comprises high-speed physical downlink shared channel (HS-PDSCH) (HS-PDSCH, High Speed-Physical Downlink Shared Channel) in the sub-district of TD-SCDMA system, is used for transmit traffic data; High-Speed Shared Control Channel (HS-SCCH, High Speed-Shared Control Channel), be used to transmit signaling information and high-speed shared information channel (HS-SICH, High Speed-SharedInformation Channel), be used for the control information of transmission user equipment feedback.

Loading condition and type of service according to this sub-district are dispatched configuration to HSDPA resource relevant in the sub-district.Determine whether that according to factors such as the data throughout of this UE, QoS needs are the HSDPA resource allocation that a UE is correlated with by RNC.

In the radio multimedium network of full grouping, need reasonably dispatch Packet Service, to guarantee the qos requirement of all kinds of business.Providing QoS to guarantee, satisfy the data rate and the packet delay restriction of active user, is the requirement of wireless high-speed data net.

In 3GPP, loaded service in the future communications system is divided into session service (Conversational), stream professional (Streaming), interactive service (Inter-active) and backstage business (Background) four classes by its qos requirement, as shown in table 1.So various and business that have a different qualities communicates simultaneously just needs simple effective and RRM mechanism that have a robustness to coordinate, and the burst transfer characteristic that Packet Service had will be brought bigger challenge to RRM.

Be safeguards system stability, when the user after network is initiated radio resource request, system need carry out access control to business.By access control, system load is controlled at acceptable degree, make better effect of dispatching algorithm performance.

At this, suppose that scheduling scheme is based upon on the desirable access control basis.All Packet Services all need to dispatch for it by packet scheduling system and obtain Radio Resource, as each TTI Radio Resource are distributed.Therefore, packet scheduling system is in core status in the RRM framework.Because session service has very high time delay sensitivity, generally when access control, transmit with regard to assigned with dedicated channel (DCH), when scheduling, do not consider.Therefore, the business that need dispatch Resources allocation is mainly streaming media service, interactive service and background service, and streaming media service and interactive service have certain time delay sensitivity and need guarantee that also the minimum transfer bit rate guarantees its QoS.Fast packet scheduling (FPS) is the dispatching algorithm that is arranged in the MAC layer, and the HSDPA system can adopt the FPS algorithm to realize service dispatching on the HS-DSCH channel, manages in HSDPA channel and the relevant physical-layer air interfaces resource of UE.For mixed service, fast packet scheduling (FPS) algorithm need be taken all factors into consideration throughput of system usually, fairness, and factors such as QoS of survice index are come scheduling resource.

At document 3GPP TS25.848, Physical layer aspects of UTRA High SpeedDownlink Packet Access, 2001.3 the most basic packet scheduling algorithm of middle description has MaxC/I algorithm and polling algorithm (Round Robin, RR), Max C/I dispatching algorithm is the dispatching algorithm that a kind of typical utilization " multi-user diversity effect " realizes maximized system capacity.Its basic thought is that remain to be served travelling carriage is sorted according to its received signal C/I predicted value, and sends according to order from big to small.Repeating query algorithm (Round Robin is called for short RR): the RR basic idea is to guarantee that the user in the sub-district communicates according to the Radio Resource that certain sequential loop of determining takies equal time.The corresponding formation of each user is to deposit data to be transferred, and the formation of non-NULL is accepted service to transmit data in the mode of repeating query when scheduling.The repeating query algorithm not only can guarantee the long-term fairness between the user, can also guarantee user's short-term fairness, and algorithm is realized simple.But this algorithm is owing to the concrete condition of not considering the different user wireless channel, so throughput of system is very low.Usually, think that the RR algorithm is the most fair, because it guarantees that the time of all CU equivalent communicates; Think that simultaneously this algorithm is performance minimum (its throughput of system is minimum) in real system.The RR algorithm is the upper bound of fairness and the lower bound of algorithm performance.

Above-mentioned two kinds of algorithms have obtained the bound of throughput of system respectively.But desirable packet scheduling algorithm should be taken into account each factor, and seeks to reach balance in some sense in real time.

Summary of the invention

In view of this, the object of the present invention is to provide a kind of Packet Service scheduling method for wireless resource based on QoS, with at mixing Packet Service, based on long-term fairness between QoS guarantee, instantaneous channel quality, user to TDD-HSDPA system down link scheduling of resource and management.

A kind of Packet Service scheduling method for wireless resource based on QoS provided by the invention comprises step:

(a) determine dispatching priority according to each user business type;

(b) for the user of identical services type in the step (a), be preferably current mean data rate less than the user resource allocation that guarantees bit rate GBR, calculate each user's priority P i, according to the priority of being calculated order from big to small is each user's distributing radio resource, and wherein said priority P i calculates according to following formula:

$P_i=\frac{R_i\left(t\right)/{\stackrel{\‾}{R}}_i\left(t\right)}{\mathrm{Timeou}{t}_i\left(t\right)}$

Timeout _i(t)＝DT _i-QT _i(t)-MTT _i

R wherein _i(t) be i user's average transmission rate, R _i(t) obtain the corresponding instantaneous transmission speed of modulation coding mode (MCS), DT for the current SIR of i user _iBe the packet loss timing: be the overtime packet loss setting-up time threshold parameter that divides into groups, MTT _iBe maximum transmission time: be the transmission time of interface aloft of packet after the maximum retransmit, QT _iBe the queuing timing: current time i user and packet data queues team head bag are placed in the time difference of base station buffer.

Wherein step (a) comprising:

The different service types user is assigned in the different business formation, carries out packet scheduling so that distinguish the QoS demand of different service types.

This method comprises that further wherein dispatching priority calculates according to following formula according to carrying out resource allocation based on buffer memory than the dispatching priority that calculates:

$P_i=\frac{R_i\left(t\right)\×{\mathrm{BR}}_i\left(t\right)}{{\stackrel{\‾}{R}}_i\left(t\right)\×\mathrm{Timeou}{t}_i\left(t\right)}$

R wherein _i(t) be i user's average transmission rate, R _i(t) obtain the corresponding instantaneous transmission speed of modulation coding mode (MCS), DT for the current SIR of i user _iBe the packet loss timing: be the overtime packet loss setting-up time threshold parameter that divides into groups, MTT _iBe maximum transmission time: be the transmission time of interface aloft of packet after the maximum retransmit, QT _iBe the queuing timing: current time i user and packet data queues team head bag are placed in the time difference of base station buffer, BR _i(t) be i user's buffer memory ratio, i.e. the ratio of the shared spatial content of i user data in the base station buffer and base station buffer total capacity.

When finishing wireless resource scheduling at every turn, resource pool is upgraded, if surplus resources is arranged, then continue to carry out scheduling of resource according to priority.

In sum, the invention provides a kind of taking into account and mix Packet Service qos requirement, the system feasible scheme of wireless resource scheduling mechanism long-term fairness, that be applicable to the TDD-HSDPA system between throughput and user in short-term.This scheme is by measuring and calculating different business and user's thereof priority, and carry out allocation of radio resources according to this priority and dispatch, carrying out fast packet scheduling with traditional Max C/I algorithm or polling algorithm compares, this technical scheme can guarantee the qos requirement of real time business, and improves throughput of system as far as possible on the basis that ensures long-term fairness between the user.Adopt method provided by the invention that the system wireless resource management is combined with the transport service type, make resource allocation more reasonable and flexible, thereby can realize adapting to the management of the required Radio Resource of mixed service in the future mobile communication system better.

Description of drawings

Fig. 1 is the sub-district part configuration diagram of cdma system;

Fig. 2 is according to HSDPA data burst structural representation of the present invention;

Fig. 3 is the dispatching method flow chart that ensures based on QOS according to of the present invention.

Embodiment

Network service quality (quality of service, be called for short QoS) is network between the user of mutual communication between the user and on the network about the agreement of message transmission with the matter of sharing.Among the 3GPP, loaded service in the future communications system is divided into session service, professional, professional four classes of interactive service and backstage of stream by its qos requirement, as shown in table 1, desired speed of all kinds of business and time delay have nothing in common with each other.

Type of service	Traffic performance	For example professional	Time and rate request
				Session service	There is cross correlation closely between each information unit in the Business Stream, the most responsive to time delay	Speech business, VoIP visual telephone	80-D max(ms) ＜2.048(Mb/s)
Stream is professional	There is cross correlation closely between each information unit in the Business Stream, responsive to time delay	The video flowing audio stream	250-D max(ms) ＜2.048(Mb/s)
				Interactive service	The request response model, the Payload content needs higher fail safe	Www web page browsing database retrieval	Without limits
The backstage business	Do not need to finish at the appointed time response, the Payload content needs higher fail safe	E-mail SMS	Without limits

Manage and Resources allocation according to dissimilar QoS.For example, give the bigger bandwidth resources of real-time service assignment; The user proposes the QoS demand according to different application.According to the operating position of resources in network, allow the user to enter network and carry out multimedia messages transmission and control and consult its QoS.For satisfied QoS is provided to the user, must provide corresponding resource such as peer-to-peer system, router and transmission bandwidth, give to guarantee these resource priority allocation.Scheduling of resource and management.After resource preengage, whether these resources be can obtain, corresponding scheduling of resource and management system also depended on.

For the Packet Service that ensures QoS, need application to determine to guarantee bit rate GBR (Guaranteed Bit Rate), for example, from application point, the GBR of Video customer requirements is higher, for the higher service rate of its application, as 64kbps, 128kbps or higher; Ensure lower GBR as professional need of www, as be made as 8kbps.

In addition, be the overtime packet loss setting-up time threshold parameter that divides into groups: packet loss is (DT) regularly.3GPP receives the packet delay requirements definition grouping times for all are correct cumulative distribution function (CDF) is less than the time delay thresholding in 95% value, as flow professional corresponding 280ms, therefore, for single grouping, its time delay can surpass 280ms but need satisfy the packet delay requirement to ensure on the statistical significance less than certain thresholding DT.Need the packet near DT preferentially to be dispatched for reducing packet loss at transmitting terminal;

The time difference that is placed in base station buffer for current time and certain user packet data queues team head bag is defined as queuing regularly (QT), can be used as to weigh be scheduled fairness and ensure the index of time delay of user;

The data that bust this need retransmit by HARQ before data retransmission was meant, the priority that why improves it are to consign to the upper strata because the data of its back just can be recombinated after will waiting it successfully to receive.Packet transmission time of interface aloft after the maximum retransmit, definition maximum transmission time (MTT);

Because the base station buffer internal memory is limited, therefore also should consider the user of priority scheduling buffered data near the internal memory limit for avoiding buffer data to overflow.At this, the shared spatial content of user data in the definition base station buffer is that buffer memory is than (BR) with the ratio of base station buffer total capacity.

In order further to understand principle of the present invention, characteristic and advantage, describe the present invention below in conjunction with the packet scheduling strategy of the TDD-HSDPA of TD-SCDMA system.Be illustrated in figure 2 as HSDPA data burst structure.For TDD-HSDPA, 6 business time-slots are divided into 1 ascending time slot and 5 descending time slots, and ascending time slot is used for transmitting channel-quality feedback (CQI), ACK/NAK feedback and the upstream data etc. of holding the base station end from UE, and spreading factor is 16; Descending time slot is mainly used to send the transmission indication and the downlink data of the end from the base station end to UE, and spreading factor is 1 or 16.

The present invention relates generally to the dispatching management of Radio Resource, under the prerequisite of the normal access network of grouping user, carry out the scheduling of Radio Resource in this hypothesis, promptly when the user applies access network, system need carry out access control and come to guarantee that the user who inserts can proper communication load control within the specific limits.

Fig. 3 is the scheduling flow figure that ensures based on QoS according to of the present invention, shows to comprise that grouping inserts and the radio resource management scenarios specific implementation flow process of packet scheduling.With reference to Fig. 3, behind subscriber access system, the base station is assigned to the different service types user in the different business formation, carries out packet scheduling with the QoS demand of distinguishing different service types.The user who inserts by grouping will wait for that packet scheduler is its Resources allocation.

Press dispatching priority, need at first scheduling to need the traffic packets of real-time Transmission,, and upgrade resource pool as the Video retransmission packet;

Ensure the video new biography user of bit rate GBR for needs, the user of promptly transmitting data first, the current mean data rate of this user is during less than GBR, and promptly the user of emergency scheduling of resource relatively need carry out priority scheduling.Be R _i(t)＜GBR _iVideo user's distributing radio resource; And to press dispatching priority be such user resource allocation, and the dispatching priority computing formula is:

$P_i=\frac{R_i\left(t\right)/{\stackrel{\‾}{R}}_i\left(t\right)}{\mathrm{Timeou}{t}_i\left(t\right)}---\left(1\right)$

Timeout _i(t)＝DT _i-QT _i(t)-MTT _i (2)

P in the formula _iBe dispatching priority, the dispatching sequence is for from big to small; R _i(t) be i user's average transmission rate; R _i(t) be the instantaneous transmission speed that the current signal interference ratio SIR of i user (Signal Inteference Ratio) obtains the MCS correspondence.And finish scheduling back renewal resource pool.

Press dispatching priority, for the interactive service user resource allocation of needs guarantee bit rate GBR, as R _i(t)＜GBR _iWWW user, and upgrade resource pool;

The dispatching priority computing formula:

$P_i=\frac{R_i\left(t\right)/{\stackrel{\‾}{R}}_i\left(t\right)}{\mathrm{Timeou}{t}_i\left(t\right)}---\left(3\right)$

Timeout _i(t)＝DT _i-QT _i(t)-MTT _i (4)

Is the value of corresponding service at this as the GBR of judgment condition and the DT parameter correspondence in the priority formula.

At last, based on the situation of surplus resources, dispatch the service-user that the no time limit required and do not require guarantee GBR in (best effort) mode of doing one's best, as video and WWW (FTP); Consider spatial cache and packet loss time two aspect factors, the present invention improves PFS and M-LWDF algorithm, and the dispatching priority computing formula is:

$P_i=\frac{R_i\left(t\right)\×{\mathrm{BR}}_i\left(t\right)}{{\stackrel{\‾}{R}}_i\left(t\right)\×\mathrm{Timeou}{t}_i\left(t\right)}---\left(5\right)$

BR wherein _i(t) be i user's buffer memory ratio, i.e. the ratio of the shared spatial content of i user data in the base station buffer and base station buffer total capacity.

Below having video, www, the scheduling of resource in the TDD-HSDPA system of FTP mixed service is that example further specifies the present invention.

TDD-HSDPA system miscellaneous service data have different priority, suppose to have in the TDD-HSDPA system user User1 of video business, User2, the user User3 of www business, User4, the user User5 of ftp business, User6.Carve t at a time, each user's parameter is respectively:

User User1:R _i(t) be 704kbps, R _i(t) be 350kbps, GBR is 384kbps, and DT is 3s, and QT is 2s, and MTT is 0.06s, and BR is 0.6.

User User2:R _i(t) be 352kbps, R _i(t) be 100kbps, GBR is 128kbps, and DT is 3s, and QT is 1.5s, and MTT is 0.06s, and BR is 0.4.

User User3:R _i(t) be 352kbps, R _i(t) be 6kbps, GBR is 8kbps, and DT is 30s, and QT is 10s, and MTT is 0.06s, and BR is 0.8.

User User4:R _i(t) be 352kbps, R _i(t) be 10kbps, GBR is 8kbps, and DT is 30s, and QT is 2s, and MTT is 0.06s, and BR is 0.4.

User User5:R _i(t) be 1056kbps, R _i(t) be 1000kbps, DT is 300s, and QT is 20s, and MTT is 0.06s, and BR is 0.5.

User User6:R _i(t) be 704kbps, R _i(t) be 300kbps, DT is 300s, and QT is 30s, and MTT is 0.06s, and BR is 0.5.

Whole scheduling process is as follows:

1) at first, the user User1 of scheduling video business and the data retransmission of user User2.

2) after having dispatched the high-priority data of front, if also have the scheduling of resource residue, then R is satisfied in scheduling _i(t)＜GBR _iThe new biography data of video.User User1 and user User2 satisfy this condition, belong to the user that need obtain service quality guarantee.Their priority is calculated according to (1) can obtain P ₁=2.14, P ₂=2.44, the resource priority allocation is given user User2, and user User2 uses the back to also have resources left to be used by user User1 again.

3) after having dispatched the high-priority data of front,, then dispatch the user User3 of www business and the data retransmission of user User4 if also have the scheduling of resource residue.

4) after having dispatched the high-priority data of front, if also have the scheduling of resource residue, then R is satisfied in scheduling _i(t)＜GBR _iThe new biography data of www.User User3 satisfies this condition, and user User4 does not satisfy.Therefore, user User3 obtains priority scheduling, and user User4 does not temporarily dispatch.If the satisfy the demand condition of priority scheduling of a plurality of users is arranged, their priority is calculated according to formula (3).

After having dispatched all data of front, if also have the scheduling of resource residue, then calculate all video, www, FTP user's priority, the user priority scheduling that the priority that calculates is high according to formula (5).

The above is an one exemplary embodiment of the present invention only, is not to be used to limit protection scope of the present invention.All any modifications of being done within the spirit and principles in the present invention, be equal to replacement, change etc., all be included in protection scope of the present invention.

Claims (4)

1, a kind of Packet Service scheduling method for wireless resource based on QoS is characterized in that, comprising:

(a) determine dispatching priority according to each user business type;

(b) for the user of identical services type in the step (a), be preferably current mean data rate less than the user resource allocation that guarantees bit rate GBR, calculate each user's priority P i, according to the priority of being calculated order from big to small is each user's distributing radio resource, and described priority P i calculates according to following formula:

$P_i=\frac{R_i\left(t\right)/{\stackrel{\‾}{R}}_i\left(t\right)}{{\mathrm{Timeout}}_i\left(t\right)}$

Timeout _i(t)＝DT _i-QT _i(t)-MTT _i

R wherein _i(t) be i user's average transmission rate, R _i(t) obtain the corresponding instantaneous transmission speed of modulation coding mode (MCS), DT for the current SIR of i user _iBe the packet loss timing: be the overtime packet loss setting-up time threshold parameter that divides into groups, MTT _iBe maximum transmission time: be the transmission time of interface aloft of packet after the maximum retransmit, QT _iBe the queuing timing: current time i user and packet data queues team head bag are placed in the time difference of base station buffer.

2, Packet Service scheduling method for wireless resource as claimed in claim 1 is characterized in that, wherein step (a) comprising:

The different service types user is assigned in the different business formation, carries out packet scheduling so that distinguish the QoS demand of different service types.

3, Packet Service scheduling method for wireless resource as claimed in claim 1 is characterized in that, this method comprises that further wherein dispatching priority calculates according to following formula according to carrying out resource allocation based on buffer memory than the dispatching priority that calculates:

$P_i=\frac{R_i\left(t\right)\×{\mathrm{BR}}_i\left(t\right)}{{\stackrel{\‾}{R}}_i\left(t\right)\×{\mathrm{Timeout}}_i\left(t\right)}$

R wherein _i(t) be i user's average transmission rate, R _i(t) obtain the corresponding instantaneous transmission speed of modulation coding mode (MCS), DT for the current SIR of i user _iBe the packet loss timing: be the overtime packet loss setting-up time threshold parameter that divides into groups, MTT _iBe maximum transmission time: be the transmission time of interface aloft of packet after the maximum retransmit, QT _iBe the queuing timing: current time i user and packet data queues team head bag are placed in the time difference of base station buffer, BR _i(t) be i user's buffer memory ratio, i.e. the ratio of the shared spatial content of i user data in the base station buffer and base station buffer total capacity.

4, Packet Service scheduling method for wireless resource as claimed in claim 1 is characterized in that, when finishing wireless resource scheduling, resource pool is upgraded at every turn, if surplus resources is arranged, then continues to carry out scheduling of resource according to priority.

Images