CN103874214A

CN103874214A - Near space self-adaptive dynamic bandwidth allocation method

Info

Publication number: CN103874214A
Application number: CN201410142360.5A
Authority: CN
Inventors: 廖勇; 宋强; 黄�俊; 谭彦婷; 杨力生
Original assignee: Chongqing University
Current assignee: Shanghai Circulation Quantum Technology Co ltd
Priority date: 2014-04-10
Filing date: 2014-04-10
Publication date: 2014-06-18
Anticipated expiration: 2034-04-10
Also published as: CN103874214B

Abstract

The invention provides a near space self-adaptive dynamic bandwidth allocation method. The near space self-adaptive dynamic bandwidth allocation method specifically comprises the steps that (1) based on the format of a universal MAC frame of existing near space Proximity-1, an emergency position and a service type position signifying the service priority are newly added to an MAC frame header; (2) based on an improved universal MAC frame, two kinds of control frames are specifically designed, and the two kinds of control frames are an aircraft bandwidth request control MAC frame format and a near space AP bandwidth response control MAC frame format; (3) channels are divided into a data channel and a control channel, wherein the data channel is specially used for transmitting data frames, the control channel is specially used for transmitting management frames and control frames, and thus the throughput rate of a system is increased; (4) based on the design of the frames and the channels, a self-adaptive dynamic bandwidth allocation process between the user aircraft and an access AP is designed. According to the near space self-adaptive dynamic bandwidth allocation method, self-adaption of bandwidth and division of the channels are achieved, the near space data transmission throughput rate is increased, and the near space data transmission reliability is improved.

Description

A kind of near space self adaptation distribution method of dynamic bandwidth

Technical field

The present invention relates to the field of the near space link protocol (Proximity-1) of near space, mainly in low rail user aircraft and face the discussion of transmitting the protocol method of data between sky AP, in existing scientific basic, the method has been proposed.

Background technology

Consultative committee for space data system (CCSDS) implements to the spacecraft of number of different types the demand jointly controlling for meeting in more complicated space mission, a kind of new SDL of developing on the basis of data system (COS) and senior data system in-orbit (AOS) in-orbit in existing routine, i.e. near space link protocol (Proximity-1Space Link Protocol).The feature of this agreement is that time delay is short, signal strength signal intensity is medium, be applicable to short distance, two-way, fixing or variation wireless link, general being applied between relatively independent spacecraft communicated by letter mutually more, as orbiter, orbital vehicle, lander, tour device (roaming vehicle), track constellation and track relaying etc.

But also there is many deficiencies in CCSDS Proximity-1 agreement at present: only divided the priority of business in (1) protocol frame format, but there is no the emergency of differentiated service, can allow urgent business can not get response; (2) although there is the differentiation concept of management data and user data in protocol frame format, do not relate to special channel and transmit dissimilar frame, the efficiency of facing the frame of sky AP processing cannot improve; (3) do not have a kind of dynamic adaptive for the bandwidth allocation methods between aircraft user and access point AP.

According to the above fact, the present invention proposes a kind of near space self adaptation distribution method of dynamic bandwidth, is applicable to face sky AP and processes dissimilar frame, the application problem in the actual space missions such as the bandwidth request control frame dynamic bandwidth allocation to different service types.

Summary of the invention

The object of the invention is to propose a kind of near space self adaptation distribution method of dynamic bandwidth, near space data transmission procedure is controlled.

The related definition of given first interchangeable frame and control frame:

We are divided into Frame, management frames and control frame the type of frame according to difference in functionality, and wherein Frame is mainly used in transmitting data, and control frame is mainly used in control information transmission, and management frames is for transmit management information.Control frame comprises bandwidth request control frame and bandwidth response control frame and other control frame of reserving.

(1) generic frame structure, see shown in accompanying drawing 1, wherein:

Version number (2bit): be generally " 10 ".

Quality of service QoS(1bit): " 0 " represents that this frame is the frame that is subject to order control, meets recipient's frame inspection, and order constraint service more is reliably provided; " 1 " represents fast frame.

Protocol data type (2bit): " 00 " represents management frames, " 01 " represents control frame, and " 10 " represent Frame, and " 11 " are reserved.

Subtype (4bit): subtype represents the different corresponding subtype of protocol data type.In this article, mainly the subtype of control frame is set forth, the definition of its subtype is shown in shown in accompanying drawing 2.

Emergency (1bit): " 0 " represents general service, order is carried out the type business." 1 " represents urgency traffic, can interrupt the business that similar priority or priority are lower.

Type of service (2bit): " 00 " represents speech business, " 01 " presentation video business, " 10 " representative digit business, " 11 " are reserved, judge priority according to type of service, binary number corresponding to type of service is less, and priority is higher, be in improved protocol, the priority of speech business is the highest.

Spacecraft mark ID(SCID) (10bit): first 5 is transmit leg ID, and latter 5 is recipient ID.

Physical channel ID(PCID) (1bit): physical communication mark.

Port definition (3bit): which physics termination the data field of designated frame should be received via.

Transmitting-receiving identifies (S or D) (1bit): " 0 " represents transmit leg transmission frame, and " 1 " represents recipient's transmission frame.

Frame length (11bit): maximum frame length 2048B, wherein frame head is 6B, load is 2042B to the maximum; Minimum frame length is 6B, and wherein frame head is 6B, and load is 0.

Frame number (8bit): for sequence control, need to count separately, not participate in frame check process.

Load (0-2042B): load region and the seamless link of frame head part, load region variable-length, is 2042B to the maximum, and minimum is 0B.In the time of transmitting data frame, in the time that the user data of transmission is greater than a frame length, user data is cut apart; In the time that user data is less than a frame length, afterbody fills out 0 to reach a frame length.

(2) Control signal frame, is shown in shown in accompanying drawing 3, the protocol data type field of its MAC head is " 01 ".In the present invention specific design 2 kinds of control frames: bandwidth request control frame and bandwidth response control frame, wherein the payload length of bandwidth request control frame is 2B, represent the size of data volume to be sent, the payload length of bandwidth response control frame is 1B, represents allocated bandwidth result.

(3) bandwidth request Control signal frame, is shown in shown in accompanying drawing 4, when user's aircraft need to send when data to facing sky AP, first sends bandwidth request control frame and faces sky AP with request and distribute bandwidth.In bandwidth request control frame, subtype is 0000 (0x0), and S or D is that 0(bandwidth request control frame is transmit leg transmission frame), frame length is 00000001000(0x8), frame number is 00000000 (0x0).The size of the data volume to be sent that loading section need to send for transmission user aircraft, accounts for 2 bytes altogether, in the time that the decimal value of the binary number representative of this part is K, indicates that the data etc. of K frame are to be sent.Because the data volume of a frame is 2B, so data volume that has K × 2B etc. is to be sent.The maximum decimal system numerical value that 2B can represent is 2 ¹⁶=65536, so the data volume of the maximum transmitted that can represent is 2 ¹⁶× 2KB=2GB.

(4) bandwidth response Control signal frame, is shown in shown in accompanying drawing 5, in the time facing the bandwidth request control frame that sky AP receives that user's aircraft sends, sends and can meet user's amount of bandwidth to user's aircraft according to current residual bandwidth situation.In bandwidth response control frame, subtype is 0001(0x1), S or D is that 1(bandwidth response control frame is recipient's transmission frame), frame length is 00000000111 (0x7), frame number is 00000000 (0x0).Loading section is for transmitting the amount of bandwidth of facing sky AP and can meet user's aircraft, 1B altogether.The total bandwidth of supposing to face sky AP is B, total bandwidth is divided into 2 ⁸=256 sub-bandwidth, the wide size of each subband is B/256, in the time that the bandwidth that can distribute is M, uses

corresponding binary number representation faces the bandwidth that sky AP can distribute.

Secondly, the present invention provides the definition of channel.

We are divided into control channel and data channel channel according to different functions, and wherein control channel occupies little bandwidth, are used for specially transmission control frame and management frames; Data channel occupies most bandwidth for transmitting user data, has so just realized data channel and control channel is separated, and has improved greatly throughput.Suppose that the sky aircraft that faces that we study has many antennas, we can be using the channel of some antennas wherein as control channel, and this channel is specifically designed to transmission control frame and management frames.

On the basis of concrete frame defined above and channel, design self adaptation Dynamic Bandwidth Allocation flow process between user's aircraft and access AP, as shown in Figure 6.

Step is 1.: user's aircraft is issued bandwidth request control frame to face sky AP by control channel, and with the incidentally size of data volume to be sent of form of load, request is faced sky AP and distributed bandwidth with transmission data (accompanying drawing 7, step100).

Step is 2.: faces sky AP and makes and replying according to the distribution condition dedicated bandwidth response control frame of current residual bandwidth, if do not have bandwidth to distribute, and acknowledges requests failure, the allocated bandwidth result part of facing in the bandwidth response control frame that sky AP replys is full 0; If there is remaining bandwidth to distribute, reply allocated bandwidth success, the corresponding binary number representation of bandwidth of actual allocated for allocated bandwidth result part.

Step is 3.: face sky AP, by control channel, bandwidth response control frame is transferred to user's aircraft, with the incidentally allocated bandwidth result (accompanying drawing 7, step104) of form of load.

Step is 4.: user's aircraft is handled it according to bandwidth response control frame, if allocated bandwidth result is 0, after one section of random time of user's aircraft wait, retransmit bandwidth request control frame (accompanying drawing 7, step106), be greater than if 0 number, user's aircraft starts to send data (accompanying drawing 7, step105) by data channel.

In step 2, face the detailed process chart of sky AP and see shown in accompanying drawing 7.

First,, according to the division of general service and urgency traffic, define urgent weight coefficient (urgent coefficient) k _em, the urgent coefficient of general service is 1, the urgent coefficient of urgency traffic is 2.And then according to the difference of each type of service, as audio frequency, image and data three classes, realize the division of priority and according to the different definition of priority business weight coefficient (business coefficient) k _se, business weight coefficient is decimal number corresponding to priority radix-minus-one complement.In the present invention, " 00 " represents speech business, " 01 " presentation video business, and " 10 " representative digit business, is easy to obtain the business weight coefficient k of speech business _se=3, the business weight coefficient k of graphic service _se=2, the business weight coefficient k of digital service _se=1.Finally, we define equivalent weight coefficient k _eqfor urgent weight coefficient k _emwith business weight coefficient k _seproduct (be k _eq=k _em× k _se), to determine that each business is finally distributed the number of bandwidth and by the situation of other service disconnection.

1. face sky AP is n the bandwidth request allocation bandwidth (step101) that synchronization arrives in the time having remaining bandwidth

Suppose that remaining bandwidth is M, the size of bandwidth on demand is respectively x ₁, x ₂, x _i..., x _n, the urgent weight coefficient k of their correspondences _emwith business weight coefficient k _serespectively k _em1, k _em2, k _emi..., k _emnand k _se1, k _se2, k _sei..., k _sen.First calculate the equivalent weight coefficient k of each business _eqi=k _emi× k _sei, i=1,2 ... n.The bandwidth that is i traffic assignments is:

x_{i}^{'} = M \times \frac{x_{i} \times k_{emi} \times k_{eqi}}{x_{1} \times k_{em 1} \times k_{se 1} + x_{2} \times k_{em 2} \times k_{eq 2} + . . . x_{i} \times k_{emi} \times k_{eqi} + . . . x_{n} \times k_{emn} \times k_{eqn}},

i＝1,2,…n （1）

For formula (1), can be according to having or not urgency traffic to be segmented in n bandwidth request.

● contain urgency traffic, directly use formula (1) to distribute.

● be all general service, emergency=0 in frame structure, its urgent coefficient k _em=1, equivalent weight coefficient k _eq=k _se.

For the general service bandwidth on demand control frame of different service types, according to priority divide level, each level is by business weight coefficient k _sedistribute bandwidth.In the design, be easy to obtain the equivalent weight coefficient k of speech business _eq=k _se=3, the equivalent weight coefficient k of graphic service _eq=k _se=2, the equivalent weight coefficient k of digital service _eq=k _se=1, so formula (1) is reduced to:

x_{i}^{'} = M \times \frac{x_{i} \times k_{sei}}{x_{1} \times k_{se 1} + x_{2} \times k_{se 2} + . . . x_{i} \times k_{sei} + . . . x_{n} \times k_{sen}}, i = 1,2, . . . n - - - (2)

For the general service bandwidth on demand control frame of identical type of service, due to their business weight coefficient k _sealso equate, can regard as according to data volume size and distribute, so formula (2) is reduced to:

x_{i}^{'} = M \times \frac{x_{i}}{x_{1} + x_{2} + . . . x_{i} + . . . x_{n}}, i = 1,2, . . . n - - - (3)

In fact,, for the urgency traffic of identical type of service, formula (3) is still set up.

2. face sky AP is n the bandwidth request allocation bandwidth that synchronization arrives in the time there is no remaining bandwidth

The size of supposing bandwidth on demand is respectively x ₁, x ₂, x _i..., x _n, the urgent weight coefficient k of their correspondences _emwith business weight coefficient k _serespectively k _em1, k _em2, k _emi..., k _emnand k _se1, k _se2, k _sei..., k _sen.

The business that cannot interrupt carrying out due to general service, so to k _em=1 request wide regardless of wearing (step102).For urgency traffic, only choose equivalent weight coefficient k _eqmaximum (is assumed to be k _eqmax) all business whether realize the judgement of break in service, other emergent operation request is also wide regardless of wearing.

In order to realize fairness, choose occupied bandwidth many, equivalent weight coefficient k _eqlittle business is interrupted, design judgment flow process following (step103):

I. the minimum value of determining the equivalent weight coefficient of all business of carrying out (is assumed to be k _s), if k _eq=k _s, do not carry out break in service, otherwise judge II;

If II. k _s< k _eqmax, and k _eq=k _sbusiness only have one, so select to interrupt this business, if having multiplely, judge III;

III. equivalent weight is k _shave multiple business, interrupt the non-emergent business of occupied bandwidth maximum, if be all urgency traffic, directly interrupt the business of occupied bandwidth maximum;

IV. the allocated bandwidth that interrupting service is taken is to the urgency traffic of bandwidth on demand, and distributing formula is (3).

Allocation result is divided into two classes:

1. be allocated successfully: face sky AP remaining bandwidth M > 0, by the amount of bandwidth of getting in the allocated bandwidth result part of bandwidth response control frame with binary number representation out.

2. distribute unsuccessfully: facing sky AP remaining bandwidth is M=0, requested service is not urgency traffic, or interrupts judgement and do not pass through etc. can not to carry out allocated bandwidth, the full zero padding of allocated bandwidth result of bandwidth response control frame in situation.

For example practical

Bandwidth has the situation of surplus, i.e. M > 0:

Situation one, face sky AP and receive sending request of different business grade simultaneously.

Suppose total bandwidth B=100MHz, subband is wide is B/256=0.39MHz, and current residual bandwidth is M=50MHz, faces sky AP(suppose that its address is 00000 in this moment) receive 5 bandwidth request control frames, all non-emergent business, are specifically shown in shown in accompanying drawing 8.

We write out its bandwidth request control frame, shown in accompanying drawing 9 take task 1 as example.Face first business weight coefficient sequence of sky AP, and the business weight coefficient that has voice is 3, the business weight coefficient of image is 2, the business weight coefficient of numeral is 1, priority X1=X5>X2=X3>X4, obtains this allocation result according to formula (2) as follows.

x_{1}^{'} = 50 \times \frac{10 \times 3}{10 \times 3 + 40 \times 2 + 40 \times 2 + 50 \times 1 + 30 \times 3} = 4.55 MHz

Allocated bandwidth result is: 4.55MHz/0.39MHz=11.67, gets 12, so allocated bandwidth result part is: 00001100.

x_{5}^{'} = 50 \times \frac{30 \times 3}{10 \times 3 + 40 \times 2 + 40 \times 2 + 50 \times 1 + 30 \times 3} = 13.64 MHz

Allocated bandwidth result is: 13.64MHz/0.39MHz=34.97, gets 35, so allocated bandwidth result part is: 00100011.

x_{2}^{'} = 50 \times \frac{40 \times 2}{10 \times 3 + 40 \times 2 + 40 \times 2 + 50 \times 1 + 30 \times 3} = 12.12 MHz

Allocated bandwidth result is: 12.12MHz/0.39MHz=31.08, gets 31, so allocated bandwidth result part is: 00011111.

x_{3}^{'} = 50 \times \frac{40 \times 2}{10 \times 3 + 40 \times 2 + 40 \times 2 + 50 \times 1 + 30 \times 3} = 12.12 MHz

All utilize for guaranteeing bandwidth, the service bandwidth result of calculation of first distributing adopts rounding-off method, and (must be the business minimum in processing priority last distribution, if there is the business that multiple priority is minimum, chooses at random one and do subtraction operation) mode adopts subtraction.

That is: x' ₄=50-4.55-13.64-12.12-12.12=7.57MHz

Allocated bandwidth result is: 7.57MHz/0.39MHz=19.41, gets 19, so allocated bandwidth result part is: 00010011.

Equally take task 1 as example, the bandwidth response control frame that faces sky AP and reply X1, as shown in Figure 10.

Situation two: simultaneously receive sending request of equal grade of service.

In fact, receive that identical the sending request of service priority is the special case of situation one, the formula that also can list according to situation one calculates simultaneously, just in calculating, carries out abbreviation, can regard as according to data volume size and distribute.Suppose that current residual bandwidth is 50MHz, receive 5 control informations in this moment, be respectively voice (00) X1,10MB; Voice (00) X2,40MB; Voice (00) X3,40MB; Voice (00) X4,50MB; Voice (00) X5,30MB.

According to formula (3), it is as follows that each business is got bandwidth:

x_{1}^{'} = 50 \times \frac{10}{10 + 40 + 40 + 50 + 30} = 2.94 MHz

2.94MHz/0.39MHz=7.54, gets 8, is encoded to 00001000.

x_{2}^{'} = 50 \times \frac{40}{10 + 40 + 40 + 50 + 30} = 11.76 MHz

11.76MHz/0.39MHz=30.15, gets 31, is encoded to 00011111.

x_{3}^{'} = 50 \times \frac{40}{10 + 40 + 40 + 50 + 30} = 11.76 MHz

11.76MHz/0.39MHz=30.15, gets 31, is encoded to 00011111.

x_{4}^{'} = 50 \times \frac{50}{10 + 40 + 40 + 50 + 30} = 14.71 MHz

14.71MHz/0.39MHz=37.72, gets 38, is encoded to 00100100.

x’ ₅＝50-2.94-11.76-11.76-14.71＝8.83MHz

8.83MHz/0.39MHz=22.64, gets 23, is encoded to 00010101.

, there is the situation of urgency traffic in situation three

Due to the emergency of urgency traffic, so its equivalent weight k _eqfor business weight k _setwice.Suppose that X4 business is urgency traffic in situation one, its equivalent weight k _eqbecome 1 × 2=2.Be respectively voice (00) X1,10MB; Image (01) X2,40MB; Image (01) X3,40MB; Numeral (urgent, 10) X4,50MB; Voice (00) X5,30MB.Face sky AP and first carry out weight sequence, X1=X5>X2=X3=X4.The bandwidth request control frame of hot job X4 is as shown in Figure 11:

, according to formula (1), each traffic assignments bandwidth is as follows:

x_{1}^{'} = 50 \times \frac{10 \times 3}{10 \times 3 + 40 \times 2 + 40 \times 2 + 50 \times 2 + 30 \times 3} = 3.95 MHz

3.95MHz/0.39MHz=10.13, gets 10, is encoded to 00001010.

x_{5}^{'} = 50 \times \frac{30 \times 3}{10 \times 3 + 40 \times 2 + 40 \times 2 + 50 \times 2 + 30 \times 3} = 11.84 MHz

11.84MHz/0.39MHz=30.36, gets 30, is encoded to 00011110.

x_{2}^{'} = 50 \times \frac{40 \times 2}{10 \times 3 + 40 \times 2 + 40 \times 2 + 50 \times 2 + 30 \times 3} = 10.53 MHz

10.53MHz/0.39MHz=27, is encoded to 00011011.

x_{3}^{'} = 50 \times \frac{40 \times 2}{10 \times 3 + 40 \times 2 + 40 \times 2 + 50 \times 2 + 30 \times 3} = 10.53 MHz

10.53MHz/0.39MHz=27, is encoded to 00011011.

x’ ₄＝50-3.95-11.84-10.53-10.53＝13.15MHz

13.15MHz/0.39MHz=33.72, gets 34, is encoded to 00100010.

There is no the situation of surplus bandwidth resources, all data bandwidths are all transmitting data.

Face bandwidth response control frame that sky AP sends to X4 as shown in Figure 12.

Situation four: there is no bandwidth surplus, receive that non-emergent business sends request.

This situation will not be distributed bandwidth, the full zero padding of allocated bandwidth result of bandwidth response control frame.After distributing in situation one, data have started to send, at this moment face sky AP and receive that request X6(is non-emergent), face the full zero padding of bandwidth response control frame allocated bandwidth result that sky AP responds.

Situation five: there is no bandwidth surplus, receive that urgency traffic sends request.

This situation can be interrupted.After distributing in situation three, data have started to send, at this moment face sky AP and receive that request X7(is urgent, speech business, 30M), obtain its equivalent weight k _eqfor k _eq=k _em× k _se=2 × 2=4.First according to equivalent weight X1=X5=3>X2=X3=X4=2, X2 so, X3, the equivalent weight k of tri-business of X4 _eq=2 are all minimumly, obtain k _s=2, only have a urgency traffic, all k _eqmax=4, and k _s=2 < k _eqmax=4, because X2 is urgent industry thing, generally do not interrupt again, so be chosen in X3, one of two service disconnection of X4, because both occupied bandwidths equate, can select an interruption at random, as interrupted X3.

Urgent as for when interrupting, in supposed situation three, there is no X3, two kinds of business of X4, at X1, X5, the formula of X2 during according to situation three distributes after bandwidth, occurs X7 request in transfer of data, because urgency traffic is a unique business that equivalent weight is minimum, at this moment just can interrupt X5 herein so.

Accompanying drawing explanation

Fig. 1 interchangeable frame form;

Fig. 2 control frame subtype;

Fig. 3 control frame form;

Fig. 4 bandwidth request control frame form;

Fig. 5 bandwidth response control frame form;

Fig. 6 user's aircraft with face sky AP interworking demonstration graph;

Fig. 7 faces sky AP process chart;

5 concrete situations of business during Fig. 8 gives an example;

Fig. 9 task X1 bandwidth request control frame form;

Figure 10 task X1 bandwidth response control frame form;

Figure 11 hot job X4 bandwidth request control frame form;

Figure 12 hot job X4 bandwidth response control frame form.

In this specification, the present invention describes with reference to specific embodiment.But, still can make various modifications and conversion obviously and not deviate from the spirit and scope of the present invention.Therefore, specification and accompanying drawing are regarded in an illustrative, rather than a restrictive.

Claims

1. a near space self adaptation distribution method of dynamic bandwidth, is characterized in that: (1) is on the form of existing near space Proximity-1 versatile MAC frame, in the type of service position of MAC head newly-increased emergency position and expression service priority; (2) on the basis of improved versatile MAC frame, specific design 2 kinds of control frames, be respectively: aircraft bandwidth request and face the control mac frame form of sky AP bandwidth response; (3) channel is divided into and controls and 2 kinds of dedicated channels of data; (4) frame based on above and channel design, has proposed the self adaptation Dynamic Bandwidth Allocation flow process between user's aircraft and AP.

2. a kind of near space self adaptation distribution method of dynamic bandwidth according to claim 1, is characterized in that:

The frame format that versatile MAC is corresponding, comprising:

Frame control domain (6 byte), wherein: 2 bit protocol version subdomains, distinguish current and future space communication protocol; The quality of service of 1 bit, 0 represents that this frame is the frame that is subject to order control, meets recipient's frame inspection, and order constraint service more is reliably provided; 1 represents fast frame; The protocol data type of 2 bits, distinguishes management frames, control frame and Frame; The subtype of 4 bits, 0000 represents bandwidth request frame, and 0001 represents bandwidth response frame, and other are reserved; The emergency of 1 bit, 0 represents general service, 1 represents urgency traffic; The type of service of 2 bits, and corresponding one by one with priority, 00 represents speech business, has limit priority, and 01 presentation video business, has inferior priority, and 10 represent data service, have low priority, and 11 is reserved; The spacecraft mark ID(SCID of 10 bits), first 5 is transmit leg ID, latter 5 is recipient ID; The physical channel of 1 bit, represents physical communication mark; The port definition of 3 bits, which physics termination the data field of designated frame should be received via; The transmitting-receiving mark of 1 bit, 0 represents transmit leg transmission frame, 1 represents recipient's transmission frame; The frame length mark of 11 bits, maximum frame length 2048B, wherein frame head is 6B, and load is 2042B to the maximum, and frame length minimum is 6B, and wherein frame head is 6B, load is 0; The frame number of 8 bits, for sequence control, need count separately, does not participate in frame check process;

Load (variable length), length in 0 byte between 2042 bytes.

3. a kind of near space self adaptation distribution method of dynamic bandwidth according to claim 1, it improves the design that innovation is aircraft bandwidth request and faces the control mac frame form of sky AP bandwidth response:

On the basis of interchangeable frame form, in MAC head, containing the protocol data type of 2 bits, distinguish management frames, control frame and Frame; The subtype of 4 bits, 0000 represents bandwidth request control frame, and 0001 represents bandwidth response control frame, and other are reserved; Load (variable length), length in 0 byte between 2042 bytes, binary number in the load of bandwidth request control frame and bandwidth response control frame corresponds respectively to user's aircraft and will send the frame number of data volume and face the bandwidth that sky AP is the distribution of user's aircraft, specific as follows:

(1) Control signal frame, the type field of its MAC head is " 01 ", in the present invention specific design 2 kinds of control frames: bandwidth request control frame and bandwidth response control frame, wherein the payload length of bandwidth request control frame is 2B, represent the size of data volume to be sent, the payload length of bandwidth response control frame is 1B, represents allocated bandwidth result;

(2) bandwidth request Control signal frame, when user's aircraft need to send when data to facing sky AP, first send bandwidth request control frame and distribute required bandwidth to ask facing sky AP, the bandwidth request control frame obtaining on the basis of control frame as above, in bandwidth request control frame, subtype is 0000, S or D is that 0(bandwidth request control frame is transmit leg transmission frame), frame length is 00000001000, frame number is 00000000; The size of the data volume to be sent that loading section need to send for transmission user aircraft, account for altogether 2 bytes, in the time of the decimal value K of the binary number representative of this part, data that indicate K frame etc. are to be sent, because the data volume of a frame is 2B, so data volume that has K × 2B etc. is to be sent, the maximum number that 2B can represent is 2 ¹⁶=65536, so the data volume of the maximum transmitted that can represent is 2 ¹⁶× 2KB=2GB;

(3) bandwidth response Control signal frame, when face sky AP receive user's aircraft send bandwidth request control frame time, send the amount of bandwidth that can meet user to user's aircraft according to current residual bandwidth situation, the bandwidth response control frame obtaining on the basis of control frame as above, in bandwidth response control frame, subtype is 0001, S or D is that 1(bandwidth response control frame is recipient's transmission frame), frame length is 00000000111, frame number is 00000000, loading section is for transmitting the amount of bandwidth of facing sky AP and can meet user's aircraft, 1B altogether, the total bandwidth of supposing to face sky AP is B, total bandwidth is divided into 2 ⁸=256 sub-bandwidth, the wide size of each subband is B/256, in the time that the bandwidth that can distribute is M, uses

corresponding binary number representation.

4. a kind of near space self adaptation distribution method of dynamic bandwidth according to claim 1, its innovation is channel to be divided into and to control and 2 kinds of dedicated channels of data:

Control channel is for transmission control frame and management frames, and data channel is for Frames such as transferring voice, image and data messages.

5. a kind of near space self adaptation distribution method of dynamic bandwidth according to claim 1, its core algorithm is to face process and the standard of sky AP dynamic bandwidth allocation:

First, provide and face the process that sky AP and user's aircraft intercom mutually:

(1) user's aircraft is issued bandwidth request control frame to face sky AP by control channel, and with the incidentally size of data volume to be sent of form of load, request is faced sky AP and distributed bandwidth with transmission data;

(2) face sky AP and make and replying according to the distribution condition dedicated bandwidth response control frame of current residual bandwidth, if there is no allocated bandwidth, acknowledges requests failure, the allocated bandwidth result part of facing in the bandwidth response control frame that sky AP replys is full 0; If there is remaining bandwidth to distribute, reply allocated bandwidth success, the corresponding binary number representation of bandwidth of actual allocated for allocated bandwidth result part;

(3) face sky AP, by control channel, bandwidth response control frame is transferred to user's aircraft, with the incidentally allocated bandwidth result of form of load;

(4) user's aircraft is handled it according to bandwidth response control frame, if allocated bandwidth result is 0, after one section of random time of user's aircraft wait, retransmit bandwidth request control frame, be greater than if 0 number, user's aircraft starts to send data by data channel;

Secondly, provide and face the method that sky AP is user's space vehicle dynamic distribution bandwidth:

According to the division of general service and urgency traffic, define urgent weight coefficient (urgent coefficient) k _em, the urgent coefficient of general service is 1, the urgent coefficient of urgency traffic is 2; And then according to the difference of each type of service, as audio frequency, image and data three classes, realize the division of priority and according to the different definition of priority business weight coefficient (business coefficient) k _se, business weight coefficient is decimal number corresponding to priority radix-minus-one complement; In the present invention, 00 represents speech business, 01 presentation video business, and " 10 " representative digit business, is easy to obtain the business weight coefficient k of speech business _se=3, the business weight coefficient k of graphic service _se=2, the business weight coefficient k of digital service _se=1; Finally, we define equivalent weight coefficient k _eqfor urgent weight coefficient k _emwith business weight coefficient k _seproduct (be ke _q=k _em× k _se), to determine that each business is finally distributed the number of bandwidth and by the situation of other service disconnection:

1. face sky AP is n the bandwidth request allocation bandwidth that synchronization arrives in the time having remaining bandwidth

Suppose that remaining bandwidth is M, the size of bandwidth on demand is respectively x ₁, x ₂, x _i..., x _n, the urgent weight coefficient k of their correspondences _emwith business weight coefficient k _serespectively k _em1, k _em2, k _emi..., k _emnand k _se1, k _se2, k _sei..., k _sen, first calculate the equivalent weight coefficient k of each business _eqi=k _emi× k _sei, i=1,2 ... n is that the bandwidth of i traffic assignments is:

x_{i}^{'} = M \times \frac{x_{i} \times k_{emi} \times k_{eqi}}{x_{1} \times k_{em 1} \times k_{se 1} + x_{2} \times k_{em 2} \times k_{eq 2} + . . . x_{i} \times k_{emi} \times k_{eqi} + . . . x_{n} \times k_{emn} \times k_{eqn}}

i＝1,2,…n

For above formula, can be according to having or not urgency traffic to be segmented in n bandwidth request:

Containing urgency traffic, directly use above-mentioned formula to distribute, is all general service, emergency=0 in frame structure, its urgent coefficient k _em=1, equivalent weight coefficient k _eq=k _se;

For the general service bandwidth on demand control frame of different service types, according to priority divide level, each level is by business weight coefficient k _sedistribute bandwidth, in the design, be easy to obtain the equivalent weight coefficient k of speech business _eq=k _se=3, the equivalent weight coefficient k of graphic service _eq=k _se=2, the equivalent weight coefficient k of digital service _eq=k _se=1, so formula can be reduced to:

x_{i}^{'} = M \times \frac{x_{i} \times k_{sei}}{x_{1} \times k_{se 1} + x_{2} \times k_{se 2} + . . . x_{i} \times k_{sei} + . . . x_{n} \times k_{sen}}, i = 1,2, . . . n

For the general service bandwidth on demand control frame of identical type of service, due to their business weight coefficient k _sealso equate, can regard as according to data volume size and distribute, thus streamline any further into:

x_{i}^{'} = M \times \frac{x_{i}}{x_{1} + x_{2} + . . . x_{i} + . . . x_{n}}, i = 1,2, . . . n

In fact,, for the urgency traffic of identical type of service, this formula is still set up;

The size of supposing bandwidth on demand is respectively x ₁, x ₂, x _i..., x _n, the urgent weight coefficient k of their correspondences _emwith business weight coefficient k _serespectively k _em1, k _em2, k _emi..., k _emnand k _se1, k _se2, k _sei..., k _sen;

The business that cannot interrupt carrying out due to general service, so to k _em=1 request is wide regardless of wearing, and for urgency traffic, only chooses equivalent weight coefficient k _eqmaximum (is assumed to be k _eqmax) all business whether realize the judgement of break in service, other emergent operation request is also wide regardless of wearing;

In order to realize fairness, choose occupied bandwidth many, equivalent weight coefficient k _eqlittle business is interrupted, and design judgment flow process is as follows:

I. determine the equivalent weight coefficient k of all business of carrying out _eqminimum value (be assumed to be k _s), if k _eq=k _s, do not carry out break in service, otherwise judge II;

IV. the allocated bandwidth that interrupting service is taken is to the urgency traffic of bandwidth on demand;

Allocation result is divided into two classes:

I. be allocated successfully: face sky AP remaining bandwidth M > 0, by the amount of bandwidth of getting in the allocated bandwidth result part of bandwidth response control frame with binary number representation out;

II. distribute unsuccessfully: facing sky AP remaining bandwidth is M=0, requested service is not urgency traffic, or interrupts judgement and do not pass through etc. can not to carry out allocated bandwidth, the full zero padding of allocated bandwidth result of bandwidth response control frame in situation.