CN100596099C - Wireless access bearer data transmission method - Google Patents

Abstract

This invention discloses a transmission method for radio access load data including: sorting data packets on a RAB and putting a same kind of data packets in a same sending queue, setting a dispatch strategy to dispatch the queue according to the strategy and sending out the data packets in the queue, which can ensure different QoS requirements of different services.

Description

Wireless access bearer data transmission method

technical field

The present invention relates to wireless communication technology, in particular to a radio access bearer (Radio Access Bearer, RAB) data transmission method.

Background technique

With the rapid development of wireless communication technology, the third-generation wireless communication system (3G) provides users with a large number of rich and colorful services, such as traditional voice services and various data services that have become the biggest highlight of 3G services. In the R99 version, it can provide a dedicated channel wireless access bearer with a maximum rate of 2M. With the R5 and R6 versions, the High Speed Downlink Packet Access (HSDPA) technology and With the introduction of Speed Uplink Packet Access (HSUPA) technology, the uplink and downlink rate of data services can even reach about 10M, which enables users to truly experience the fun brought by wireless data application services such as wireless Internet access, wireless video, and wireless downloading. It can be said that , The third-generation wireless communication system has opened a new wireless digital era.

The RAB of the data domain (Packet Switched, PS) can be divided into four types according to the transmission type, namely session type, stream type, interactive type and background type. The latter two types of services are also called Best Effort (BE) services, which are commonly referred to as best-effort services, corresponding to services with lower latency requirements but higher accuracy requirements. Such as web browsing, file transfer protocol (FTP) downloading, etc.

In practical applications, one RAB usually carries multiple application data. For example, after a user establishes wireless access, he may perform operations such as web browsing, FTP download, or email (EMAIL) at the same time. Data packets of various applications will be sent or received through this RAB. Due to the different properties of various applications, the expectations for data transmission rates are also different. How to ensure the fairness between different applications built on a RAB and reflect their respective Quality of Service (QoS) has become an industry challenge. The focus of attention of all parties. The existing RAB data transmission methods mainly include the following types:

1. The data packets in a RAB are uniformly mapped to a transport channel by a logical channel for transmission, such as a dedicated channel (Dedicated Channel, DCH) or a dedicated media access control flow (Mac-d flow) under HSDPA, that is to say , the data packets in a RAB are sent completely according to the principle of first come first served.

Usually, users need to operate multiple applications on one RAB. Various applications have different requirements for data transmission rates. For example, users perform FTP downloads and web browsing at the same time. Generally, users obviously hope that the requested web pages can be quickly accessed. Responsive, and not particularly concerned about a slight drop in FTP download rate. However, since the data packets in the RAB are scheduled completely according to the first-come-first-served principle, if there are a large number of FTP download data packets to be transmitted, it will inevitably cause web browsing data packets to be congested to a certain extent, which cannot meet the requirements. The QoS requirements of various services cannot meet the performance requirements of users' actual operations.

2. Through the cache in the Radio Network Controller (RNC), which is commonly referred to as the interface cache of the wired network and the wireless network, the data packets transmitted from the wired network are cached. The wireless link is the bottleneck of the entire end-to-end link, and the interface cache is usually considered to be the cache at the bottleneck. It can buffer data packets from the wired network and tolerate certain bursts. To a certain extent, the utilization rate of the air interface bandwidth is guaranteed.

Since the size of the interface cache is usually allocated when wireless access is established, if the cache allocation is small, then in the face of higher bursty data packets or increased data traffic, there will be buffer overflow and continuous Packet loss, for a responsive flow based on the Transmission Control Protocol (TCP), packet loss will lead to a sharp decrease in the congestion window and a decrease in throughput; if the cache allocation is large enough to ensure no packet loss, this requires a lot of A large cache, and the utilization rate of the cache is not high, and resources cannot be used effectively. Moreover, a large cache will make the queuing queue in the cache very long, which will not only increase the queuing delay of data packets in the cache, but also cause end-to-end With the increase of end-to-end delay, there will also be a situation where one stream exclusively caches, which will greatly increase the delay of other streams and reduce the throughput, which will affect the fairness among various services. For example, when a user uses Hypertext Transfer Protocol (HTTP) to browse a web page on a link where FTP files are being transferred, if the FTP stream occupies a lot of cache, it will cause the data packets of the newly established HTTP service to experience a long time. Long queuing delay not only reduces the throughput, but also seriously affects the interactivity, reduces the service experience of users, fails to meet the QoS requirements of the service, and may even cause the initial connection establishment request to fail due to timeout. In addition, due to the burstiness of data packets and the variability of data traffic, it is impossible to allocate a buffer with an appropriate size when wireless access is established.

3. Use Active Queue Management (AQM) to manage the interface cache, predict the upcoming congestion by observing the cache occupancy, and notify the sender to reduce the rate through active packet loss or marking to avoid congestion. A tradeoff between throughput and latency is achieved.

Although the use of AQM can achieve a compromise between throughput and delay, for different services, some may wish to have higher throughput, and some may wish to have lower delay. AQM cannot be based on the QoS of the business. Requirements are handled separately. For example, the FTP service itself has no requirement for delay, but for throughput. After adopting AQM, the throughput will be reduced to a certain extent in exchange for lower delay, which is meaningless for the FTP service.

Contents of the invention

In view of this, the purpose of the present invention is to provide a wireless access bearer data transmission method to ensure different QoS requirements of different services.

In order to achieve the above object, the technical solution provided by the present invention comprises the following steps:

A. Classify the data packets carried on the radio access bearer RAB, and put the data packets of the same category into the same sending queue;

B. Set a scheduling policy, schedule the queue according to the set scheduling policy, and send out the data packets in the queue.

Wherein, the classification in step A includes: classifying the data packets carried on the RAB in the packet data convergence protocol PDCP entity corresponding to the RAB.

The classifying the data packet in the PDCP entity includes: the PDCP entity analyzes the header of the data packet carried on the RAB, and determines the type of the data packet according to the header.

The PDCP entity parsing the data packet header includes: the PDCP entity parsing the network layer protocol header, or/and transport layer protocol header, or/and application layer protocol header of the data packet.

The classification in step A includes: classifying the data packets carried on the RAB according to the QoS characteristics of the data packets.

When the QoS characteristic is a time-delay requirement characteristic, the classification includes: classifying video-on-demand and streaming media as high-delay class; classifying web browsing and instant messaging as medium-delay class; classifying file transfer protocol FTP download , Sending and receiving email EMAIL is classified as a low-latency class.

Wherein, the setting of the scheduling policy in step B includes: setting the priority;

The scheduling according to the set scheduling strategy includes: scheduling the queue according to the set priority.

The setting priority includes: setting priority for the queue according to the QoS characteristics of the data packets in the queue.

When the QoS characteristic is a delay requirement characteristic, the setting priority according to the QoS characteristic includes: setting priority for the queue according to the delay requirement characteristic of the data packets in the queue, the priority level of the queue and the data packets in the queue Latency requirements are proportional to high and low characteristics.

Setting the scheduling policy in step B includes: setting a fairness policy;

The scheduling according to the set scheduling strategy includes: scheduling according to the length of time that the queues have not been scheduled, and the scheduling order of the queues is proportional to the length of time that the queues have not been scheduled.

Before sending the data packet, it further includes: performing active queue management on the queue.

The active queue management of the queue includes: determining the active queue management parameters of the queue according to the QoS characteristics of the data packets in the queue, or/and service flow, or/and the number of service connections, and controlling the queue according to the determined active queue management parameters. Perform proactive queue management.

When the QoS characteristic is a delay requirement characteristic, and the active queue management parameter is a target queue length,

The determining the active queue management parameters according to the QoS characteristics includes: determining the target queue length according to the delay requirement characteristics of the data packets in the queue, and the length of the target queue length is inversely proportional to the delay requirement characteristics of the data packets in the queue.

When the active queue management parameter is a marking threshold,

The determining the active queue management parameter according to the service flow includes: determining the marking threshold of the queue according to the service flow in the queue, and the marking threshold of the queue is inversely proportional to the service flow in the queue;

The determining the active queue management parameter according to the number of service connections includes: determining the marking threshold of the queue according to the number of service connections in the queue, and the marking threshold of the queue is inversely proportional to the number of service connections in the queue.

When the active queue management parameter is marking probability,

The determining the active queue management parameter according to the service flow includes: determining the marking probability of the queue according to the service flow in the queue, and the marking probability of the queue is proportional to the size of the service flow in the queue;

The determining the active queue management parameter according to the number of service connections includes: determining the marking probability of the queue according to the number of service connections in the queue, and the marking probability of the queue is proportional to the number of service connections in the queue.

The process of active queue management further includes: dynamically adjusting active queue management parameters.

It can be seen that, the present invention classifies the data packets carried on the RAB, puts the data packets of different categories into different sending queues for sending, and realizes the separate transmission of various service data packets on one RAB; and , in order to ensure the different QoS requirements of different services on a RAB, a scheduling policy can be set, and each queue can be scheduled according to the set scheduling policy. The timeliness of the data transmission; in addition, the QoS of the service can be further ensured by performing active queue management on each queue, for example, the length of the queue where the service data packets with high delay requirements are kept at a relatively short level to reduce the Low end-to-end delay ensures user service experience, and maintains the queue length of service data packets with low delay requirements at a relatively long level to ensure throughput requirements. In short, the method provided by the present invention can guarantee different QoS requirements of different services on one RAB, guarantee user's service experience, and improve service quality.

Description of drawings

FIG. 1 is a flow chart of a wireless access bearer data transmission method in the present invention;

FIG. 2 is a flow chart of a method for transmitting radio access bearer data in an embodiment of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and examples.

Referring to Fig. 1, the wireless access bearer data transmission method in the present invention mainly includes the following steps:

Step 101: Classify the data packets carried on the radio access bearer RAB, and put the data packets of the same type into the same sending queue.

Step 102: Set a scheduling policy, schedule the queue according to the set scheduling policy, and send out the data packets in the queue.

In the PS service, whether it is uplink data transmission or downlink data transmission, the data will go through packet data convergence protocol (Packet Data Convergence Protocol, PDCP), radio link control (Radio Link Control, RLC), dedicated media access control (Mac -d) and other protocol entities are delivered sequentially. The following downlink packet data transmission is taken as an example, and the method of the present invention is described in detail. Referring to FIG. 2, the RAB data transmission method in this embodiment mainly includes the following steps:

Step 201: Downlink packet data such as Point to Point Protocol (Point to Point Protocol, PPP) message, Internet Protocol version 4 (Internet Protocol version 4, IPv4) message, or Internet Protocol version 6 (Internet Protocol version 6, IPv6) Messages, etc., are encapsulated by the User plane part of GPRS Tunneling Protocol (GTPU) and sent to the RNC by the GPRS Support Node (GSN), and the Iu interface user plane of the PS service (Iu User Plane, IUUP) adopts the transparent mode, and the GTPU data packet is directly delivered to the PDCP entity corresponding to the RAB.

Step 202: The PDCP entity classifies the data packets carried on the RAB.

Since the RAB in the PS domain can only correspond to one PDCP entity, the data packets carried on the RAB can be classified in the PDCP entity corresponding to the RAB. The PDCP entity analyzes the header of the data packet carried on the RAB, and determines the type of the data packet according to the header, for example, parses the header of the network layer protocol, or the header of the transport layer protocol, or the header of the application layer protocol of the data packet; or, Analyzing the network layer protocol header and the transport layer protocol header of the data packet; or parsing the network layer protocol header, the transport layer protocol header, and the application layer protocol header of the data packet.

Classification can be carried out according to the QoS characteristics of data packets. For example, according to the characteristics of delay requirements of each data packet, the delay level of applications such as video-on-demand and streaming media is configured as high, and they are classified as high-latency class; Applications such as browsing and instant messaging are configured with medium latency levels, which are classified as medium latency levels; applications such as FTP downloads, sending and receiving emails are configured with low latency levels, and are classified as low latency levels.

Step 203: Put different types of data packets into different sending queues.

Step 204: Perform active queue management on each queue.

The active queue management parameters of each queue can be determined according to the data packet QoS characteristics, or/and service flow, or/and the number of service connections in each queue, and active queue management is performed on each queue according to the determined active queue management parameters. Wherein, the active queue management parameters include target queue length, marking threshold, marking probability and the like.

For example, the target queue length of each queue is determined according to the delay requirement characteristic in the QoS characteristic of each queue data packet, and the length of the target queue length of each queue is set to be inversely proportional to the delay requirement characteristic of the data packet in each queue. That is to say, keep the target queue length of the queue where the high-latency service data packets are located at a relatively short level to reduce the end-to-end delay and ensure user service experience; keep the target queue length of the queue where the low-latency service data packets are located The queue length is maintained at a long level to guarantee throughput requirements.

The marking threshold of the queue can also be determined according to the service flow or the number of service connections. For example, the marking threshold of the queue is set to be inversely proportional to the size of the service traffic in the queue and inversely proportional to the number of service connections in the queue. In addition, the marking probability of the queue can also be determined according to the business flow or the number of business connections. For example, the marking probability of the queue can be set to be proportional to the size of the business traffic in the queue and proportional to the number of business connections in the queue.

In addition, in the process of active queue management, active queue management parameters can be dynamically adjusted according to changes in actual conditions.

Wherein, step 204 is an optional step.

Step 205: Set a scheduling policy, schedule each queue according to the set scheduling policy, and send out the data packets in each queue.

The scheduling policy may be a priority setting, for example, setting the sending priority for each queue according to the QoS characteristics of the data packets in each queue, and scheduling each queue according to the set priority. For example, the priority of each queue is set according to the delay requirement characteristic in the QoS characteristic of the data packet in each queue, and the priority of each queue is set to be proportional to the delay requirement characteristic of the data packet in each queue. That is to say, set the priority of the queue where the high-latency class business data packets are located to be high, set the priority of the queue where the low-latency class service data packets are located to be low, and ensure high latency by preferentially scheduling high-priority queues Timely delivery of business data.

In addition, in order to ensure fairness among various applications, various issues should be considered comprehensively during scheduling, such as scheduling issues between queues with the same priority to prevent low-priority queues from being scheduled for a long time The problem. This can be solved by setting a fairness strategy. For example, when scheduling, scheduling is performed according to the length of time that the queue has not been scheduled. The order of queue scheduling is proportional to the length of time that the queue has not been scheduled. That is to say, priority scheduling Queue not dispatched to.

It should be noted that the method provided by the present invention is not only applicable to downlink data transmission, but also applicable to uplink data transmission. The classification, active queue management, scheduling and other processing processes in uplink data transmission are consistent with those described in FIG. 2 , and are not repeated here. Describe them in detail.

It can be seen that the method provided by the present invention can guarantee different QoS requirements of different services on one RAB, guarantee user's service experience, and improve service quality.

The purpose, technical solutions and beneficial effects of the present invention have been further described in detail above. It should be understood that the above description is not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. shall be included in the protection scope of the present invention.

Claims (12)

1, a kind of radio access bear data transmission method is characterized in that, this method may further comprise the steps:

A, according to the service quality QoS characteristic of packet, in the PDCP PDCP of RAB RAB correspondence entity, the packet that is carried on the RAB is classified, the packet of same classification is put in the same transmit queue;

B, according to the packet QoS characteristic in each formation or/and service traffics or/and professional linking number, determine the active queue management parameter of each formation, and active queue management is carried out in each formation respectively according to the active queue management parameter of each formation of determining; Scheduling strategy is set, described formation is dispatched, the packet in the described formation is sent according to the scheduling strategy that is provided with.

2, method according to claim 1 is characterized in that, described in the PDCP entity packet classification comprises: the PDCP entity is resolved the packet packet header that is carried on the RAB, according to the classification of packet header specified data bag.

3, method according to claim 2, it is characterized in that described PDCP entity is resolved packet packet header and comprised: the PDCP entity to network layer protocol packet header of packet or/and transport layer protocol packet header or/and application layer protocol packet header resolve.

4, method according to claim 1 is characterized in that, when described QoS characteristic was the delay requirement characteristic, described classification comprised: video request program, Streaming Media are classified as high time delay grade class; Web page browsing, instant messaging are classified as middle time delay grade class; File transfer protocol (FTP) FTP is downloaded, and the EMAIL that sends and receive e-mail is classified as low time delay grade class.

5, method according to claim 1 is characterized in that, the described scheduling strategy that is provided with of step B comprises: priority is set;

The described scheduling according to the scheduling strategy that is provided with comprises: according to the priority that is provided with described formation is dispatched.

6, method according to claim 5 is characterized in that, the described priority that is provided with comprises: the QoS characteristic according to packet in the formation is that formation is provided with priority.

7, method according to claim 6, it is characterized in that, when described QoS characteristic is the delay requirement characteristic, describedly according to the QoS characteristic priority is set and comprises: the delay requirement characteristic according to packet in the formation is that formation is provided with priority, and the delay requirement characteristic of packet just is directly proportional in the priority height of described formation and the formation.

8, method according to claim 1 is characterized in that, the described scheduling strategy that is provided with of step B comprises: the fairness strategy is set;

The described scheduling according to the scheduling strategy that is provided with comprises: dispatch according to the time length that formation is not scheduled, the time length that the scheduling precedence and the formation of formation are not scheduled is directly proportional.

9, method according to claim 1 is characterized in that, described QoS characteristic is the delay requirement characteristic, when described active queue management parameter is object queue length,

Describedly determine that according to the QoS characteristic active queue management parameter comprises: the delay requirement characteristic according to packet in the formation is determined object queue length, and the delay requirement characteristic of packet just is inversely proportional in the length of described object queue length and the formation.

10, method according to claim 1 is characterized in that, when described active queue management parameter is the mark thresholding,

Describedly determine that according to service traffics the active queue management parameter comprises: determine the mark thresholding of formation according to the service traffics in the formation, the mark thresholding size of described formation is inversely proportional to the service traffics size in the formation;

Describedly determine that according to professional linking number the active queue management parameter comprises: determine the mark thresholding of formation according to the professional linking number in the formation, how many mark thresholding sizes of described formation is inversely proportional to the professional linking number in the formation.

11, method according to claim 1 is characterized in that, when described active queue management parameter is marking probability,

Describedly determine that according to service traffics the active queue management parameter comprises: determine the marking probability of formation according to the service traffics in the formation, the marking probability height of described formation is directly proportional with the service traffics size in the formation;

Describedly determine that according to professional linking number the active queue management parameter comprises: determine the marking probability of formation according to the professional linking number in the formation, how many marking probability height of described formation is directly proportional with the professional linking number in the formation.

12, method according to claim 1 is characterized in that, further comprises in the process of carrying out active queue management: the active queue management parameter is dynamically adjusted.

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