CN103457875A - Message queue control method based on multi-priority in Internet of vehicles - Google Patents

The invention discloses a message queue control method based on multi-priority in the Internet of vehicles. According to the message queue control method based on the multi-priority in the Internet of vehicles, all the messages are divided into different priorities when messages are generated by vehicles, the messages are then put into different control queues according to the priorities of the messages, and the messages in the corresponding queues are sent according to the sending priorities of the control queues when the messages are transmitted. The message queue control method based on the multi-priority in the Internet of vehicles is reliable in communication service, and capable of providing different time delays according to Qos demands of different service types and providing guarantees for throughput, reliability and other performance.

Message queue control method based on multipriority in the car networking

Technical field

The present invention designs a kind of car networking wireless communication technology, especially relates to a kind of method that in car networking, message queue is controlled.

Background technology

The car networking is as emerging vehicle communication technology, for mobile subscriber on the way provides seamless Connection Service, can realize between vehicle and vehicle, vehicle and the direct multi-hop wireless communication of roadside infrastructure, to provide multiple many aspects of vehicle safety applications and non-security application.With respect to traditional mobile ad-hoc network, the car networking has self exclusive characteristic:

(1) high dynamic topological structure.Because the topological mechanism of the networking of the high-speed mobile car between vehicle often changes.

(2) frequent network interrupts.Same reason, the link meeting of car networking often changes.Particularly, when traffic density is not high, the possibility that network interrupts can be higher.A kind of feasible solution is to lay in advance some via nodes or access point to keep connective along road.

(3) enough energy and memory space.Communication node in the car networking is automobile rather than little handheld device, the energy that they will be larger and power (comprising memory space and data processing).

(4) mobility model and prediction.Although the vehicle node high-speed motion, their movement often is limited to highway and the avenue of having built up, so, as long as speed and street map are provided, the to-be of vehicle just can be predicted.

(5) strict time delay restriction.In some car working application, network does not need high data rate but the strict time delay restriction of needs.Just because of above these characteristics, make the method for routing of car networking have a lot of new problems and new challenge, traditional data transfer path system of selection is difficult to obtain desirable performance in the car networking.

Be different from MANET, the application scenarios variation of car networking, comprise the application of vehicle safety class, the application of road traffic efficiency class, and information and the application of amusement class, therefore, different messaging services has different Qos requirements.In the scheduling of message, although the control of queue mode of most of transport network layer is using the end-to-end time delay performance as important indicator, although met the delay requirement of general message, but, for urgent security message, rely on the common queue control mode often can not be forwarded to timely destination node.When destination node has a lot of or even a slice geographic area, more can not meet delay requirement especially.For example, if by the control of queue mode of first in first out, can cause after some to high time delay, the security message of high reliability request can't guarantee real-time, even cause that accident occurs.Adopt common priority queue control mode, though can guarantee that application has Qos (Quality of Service, service quality) preferably in real time, but due to the increasing non-security application of car networking, cause the grouping in Low Priority Queuing for a long time to can not get processing, cause " hunger ".And if adopt the control mode of common Weighted Fair Queuing, equally also can cause that high-priority message can not get the problem of processing in time.

Then in actual applications, same vehicle tends to face the situation that needs to send multiple message in same amount of time, as can be seen here, provide a kind of message queue control method of high efficient and reliable extremely to be necessary, thereby guarantee message that real time business produces can be fast, efficient forwarding, other business can access fair forwarding.

Summary of the invention

Can't realize for various message queue control programs in existing car networking the problem that the message queue of high efficient and reliable is controlled, the object of the present invention is to provide a kind of message queue control method that reliable communication service is provided, the performance guarantees such as different delay, throughput, reliability are provided according to different service types Qos demand.

In order to achieve the above object, the present invention adopts following technical scheme:

Message queue control method based on multipriority in the car networking, when described control method produces message at vehicle, be divided into different priorities for each message; According to the priority of message, message is put into to different control queues again; When transmission of messages, according to the transmission priority level of controlling queue, send the message in corresponding queue.

In the preferred version of this this method, described control method specifically comprises the steps:

1) message vehicle produced is divided into different priorities;

2) message enters the different queues of controlling at transport network layer according to the priority of self: wherein, the message of high priority grade enters High-Priority Quene, described High-Priority Quene is the high priority fifo queue, and, while in this queue, message being arranged, preferentially send this queue message; In, the message of low priority grade enters Low-Priority Quene, described Low-Priority Quene, be the low priority fifo queue;

3) when carrying out the message transmission, at first check in High-Priority Quene queue whether packet(message bag arranged), if having, this queue message preferentially occurs; If nothing, send the message in Low-Priority Quene queue.

Further, in described step 1), by the network application layer of source vehicle node, produce massage(message), and the header(packet header in each packet) priority of DE_SignPriority field mark packet of part.

Further, described Low-Priority Quene adopts the Weighted Fair Queuing of 3 kinds of different transmitting time weights to put into the message of corresponding priority level, if the some queue fulls in Low-Priority Quene, the last message arrived is overflowed and abandoned.

Further, in described step 3), Low-Priority Quene sends corresponding packet according to the Packet Generation mode in Weighted Fair Queuing, and the time that the packet in the 3 kinds of different transmitting time weights queue in Weighted Fair Queuing is sent out is than being 3:2:1.

Compared with prior art, scheme provided by the invention has following advantage:

1. the invention provides two kinds of different message send queues, the low time delay of security message, the requirement of high reliability have been guaranteed, guaranteed again the throughput requirement of non-security message, effectively meeting the message that car networking different application (application of car networking mainly contains three aspects:: improve traffic safety, improve traffic efficiency, increase amusement etc.) produces has different Qos demand (mainly comprising time delay, reliability, throughput etc.) simultaneously.

2. the low priority level data in the present invention, by using Weighted Fair Queuing to send, can guarantee that the message of higher priority and lower priority can have fair transmitting time, not there will be lower priority message starvation to occur forwarding.

3. the present invention, by multiple queue is set, has avoided only using in the fifo queue method occurring that real time business can not obtain the shortcoming forwarded in real time.

4. the message that is 2 by priority level in the present invention, minute queue of the Low-Priority Quene that to enter separately the transmitting time weights be 1, needn't wait for the transmission of other priority level message to guarantee this message when sending, thereby can directly enter sending processor, thereby can meet its delay requirement as far as possible.

The accompanying drawing explanation

Further illustrate the present invention below in conjunction with the drawings and specific embodiments.

Fig. 1 is the schematic diagram that in the present invention, the message queue based on multipriority is controlled;

Fig. 2 is after vehicle node of the present invention receives message, to the process chart of packet;

Fig. 3 is a kind of application scenarios schematic diagram of the present invention.

Embodiment

For technological means, creation characteristic that the present invention is realized, reach purpose and effect is easy to understand, below in conjunction with concrete diagram, further set forth the present invention.

Referring to Fig. 1, it is depicted as the schematic diagram that the present invention realizes the message queue control method based on multipriority in the car networking.As seen from the figure, the present invention realizes that the scheme that in the car networking, message queue is controlled is as follows:

1) message at first, vehicle produced is divided into different priorities.

2) follow, the message with different priorities enters the different queues of controlling at transport network layer.

Send effect in order to reach good control, it is two large classes that the present invention will control cohort design:

High-Priority Quene, it is the high priority fifo queue, and while in this queue, message being arranged, preferentially sends this queue message.

Low-Priority Quene, it is the low priority fifo queue.This queue is comprised of the Weighted Fair Queuing of 3 kinds of different transmitting time weights, and queue in each minute is a fifo queue, the transmitting time weights that the Weighted Fair Queuing of 3 kinds of different transmitting time weights is corresponding are respectively 3,2,1, i.e. the time that packet in 3 kinds of different transmitting time weights queue is sent out is than being 3:2:1.

For the control queue of this structure, the present invention, according to the different priorities of message, will have high-grade priority message and enter High-Priority Quene, if this queue full, the last message arrived is overflowed and abandoned; In by other priority being, low-grade message enters in the Weighted Fair Queuing of corresponding transmitting time weights according to the grade of self priority, if some minute queue full in Low-Priority Quene, the last message arrived is overflowed and is abandoned.

3) last,, when carrying out the message transmission, at first check in High-Priority Quene queue whether packet(message bag is arranged), if having, this queue message preferentially occurs; If nothing, send again the message in Low-Priority Quene queue, Low-Priority Quene sends corresponding packet according to the Packet Generation mode in Weighted Fair Queuing, and the time that the packet in the 3 kinds of different transmitting time weights queue in Weighted Fair Queuing is sent out is than being 3:2:1.

As from the foregoing, the present invention is by two kinds of different message send queues, the low time delay of security message, the requirement of high reliability have been guaranteed, guaranteed again the throughput requirement of non-security message, effectively meeting the message that car networking different application (application of car networking mainly contains three aspects:: improve traffic safety, improve traffic efficiency, increase amusement etc.) produces has different Qos demand (mainly comprising time delay, reliability, throughput etc.) simultaneously.

Send by the use Weighted Fair Queuing for the low priority level data simultaneously, can guarantee that the message of higher priority and lower priority can have fair transmitting time, not there will be lower priority message starvation to occur forwarding.

Based on above-mentioned principle, the detailed process that the present invention carries out message queue control in the car networking is as follows:

A) network application layer of source vehicle node produces massage, and the priority of the DE_SignPriority field mark packet of the part of the header in each packet.According to SAE J2735, the message in the car networking can be divided into 8 grades (0-7), and higher grade, and the priority of message is higher.

Wherein, the priority of message is divided two standards: the one, and importance, the 2nd, urgency level.In concrete car networking, the message priority grade classification is as shown in table 1:

Table 1

As seen from the above table, the priority level of security message is not necessarily very high.As Emergency Vehicle Alert message, priority is 5; The priority of Public Safety class message is 3-6, and some is also less demanding to time delay.Although the priority of some non-security message is not high, time delay is also had to requirement, as the delay requirement of paying by mails is less than 10ms.

B) the source vehicle node, by table of query and routing, finds the neighbours' vehicle node of oneself, and the message of dividing different priorities that will produce is issued suitable neighbours' vehicle node (this vehicle node also is called middle vehicle node).

C) referring to Fig. 2, after middle vehicle node receives massage, this massage is transferred to transport network layer, the Classifier of transport layer is by the DE_SignPriority field of header part in each packet of inquiry, judge the residing priority of this message, and according to corresponding priority, each packet is put into to different control queues, detailed process is as follows:

If DE_SignPriority is 7 or 6, this packet puts into High-Priority Quene queue, if this queue full overflows, the packet finally arrived is dropped;

If DE_SignPriority is 5 or 4, this packet puts into the Low-Priority Quene that the transmitting time weights are 3 and divides queue, if this queue full overflows, the packet finally arrived is dropped;

If DE_SignPriority is 3,0 or 1, this packet puts into the Low-Priority Quene that the transmitting time weights are 2 and divides queue, if this queue full overflows, the packet finally arrived is dropped;

If DE_SignPriority is 2, this packet puts into the Low-Priority Quene that the transmitting time weights are 1 and divides queue, if this queue full overflows, the packet finally arrived is dropped.

Due to Message Time Delay demand<10ms that priority level is 2, requirement of real-time is high, and the Message Time Delay demand that priority level is 1,3 is all > 10ms, requirement of real-time is not high.Thereby the message that is 2 of the priority level in the present invention, the Low-Priority Quene that to enter separately the transmitting time weights be 1 divides queue, needn't wait for the transmission of other priority level message to guarantee this message when sending, thereby can directly enter sending processor, thereby can meet its delay requirement as far as possible.

While d) in High-Priority Quene and Low-Priority Quene, packet being arranged, the packet in High-Priority Quene will preferentially be sent, and with the security message of guaranteeing high priority, is forwarded in time, guarantees traffic safety.

E) if in High-Priority Quene queue without packet, according to the Packet Generation mode in Weighted Fair Queuing, send the packet in Low-Priority Quene queue, be that the time ratio that the packet in the 3 kinds of different transmitting time weights queue in Weighted Fair Queuing is sent out is 3:2:1, the message that so can guarantee higher priority and lower priority can have fair transmitting time, not there will be lower priority message starvation to occur forwarding.

Below further illustrate the solution of the present invention by a concrete application example.

Referring to Fig. 3, it is depicted as and utilizes the scheme that the invention provides to carry out a kind of application scenarios schematic diagram that in the car networking, message queue is controlled.

In this scene, the S1 on road, S2 are the vehicle source node, and D1, D2 are the vehicle destination node, and other common vehicle are numbered 1.The message that source node vehicle S1 produces need to be transmitted to purpose vehicle D1, and the message that source node vehicle S2 produces need to be transmitted to purpose vehicle D2.

In the first step, source vehicle node S1 produces a security message message1, and DE_SignPriority in packet1 packet header is labeled as to 7; Source vehicle node S2 produces an entertainment applications message m essage2, and DE_SignPriority in packet2 packet header is labeled as to 3(can be in Table 1).

In the 4th step, by inquiry, obtain the DE_SignPriority=7 in packet1, and High-Priority Quene queue less than, this packet is put into to High-Priority Quene queue.

Obtain the DE_SignPriority=3 in packet2 by inquiry, and the Low-Priority Quene queue that is 2 of transmitting time weights less than, this packet is put into to the Low-Priority Quene queue that the transmitting time weights are 2.

In the 6th step, package forward in High-Priority Quene queue is complete, send the packet in Low-Priority Quene queue, during the Low-Priority Quene queue of pointed weight=2 to be sent, packet2 starts to be forwarded, until forward complete (can referring to Fig. 1).

Above demonstration and described basic principle of the present invention, principal character and advantage of the present invention.The technical staff of the industry should understand; the present invention is not restricted to the described embodiments; that in above-described embodiment and specification, describes just illustrates principle of the present invention; without departing from the spirit and scope of the present invention; the present invention also has various changes and modifications, and these changes and improvements all fall in the claimed scope of the invention.The claimed scope of the present invention is defined by appending claims and equivalent thereof.