CN102055531B - Method for improving transmission performance of TCP in wireless sensor network - Google Patents

Abstract

The invention relates to a method for improving the transmission performance of a transmission control protocol (TCP) in a wireless sensor network. The method comprises the following steps of: determining the channel state space, the state transition probability and the secondary user observation space of a wireless sensor network system; determining the combination action space of a secondary user; determining an in-time feedback and an overall feedback; calculating to the optimal action strategy set of the secondary user in the wireless sensor network system according to the in-time feedback and the overall feedback; and determining the optimal channel selected by the current TCP transmission according to the optimal action strategy set. By the method for improving the transmission performance of the TCP in the wireless sensor network, the optimal channel of a TCP flow is selected according to frequency spectrum detection, access determination, a physical layer modulating and encoding scheme and the frame size of a data link layer in the wireless sensor network, so that the flow of the TCP is optimized and is substantially improved; and the method has the characteristics of quick and convenient processing procedure, stable and reliable working performance and wide application range.

Description

Improve the method for TCP transmission performance in the wireless-aware network

Technical field

The present invention relates to wireless communication field, particularly wireless-aware network technical field specifically refers to improve in a kind of wireless-aware network the method for TCP transmission performance.

Background technology

Wireless-aware network is considered to a kind of not high up-and-coming technology of the availability of frequency spectrum of handling, and it allows unauthorized user to operate at the frequency spectrum that is not assigned.The flow of physical layer is mainly paid close attention in the research activities that nearest multichannel obtains.It is to obtain the scheme that problem proposes for solving the multichannel chance that myopia detects strategy, and it maximizes the average discharge of physical layer by using a kind of detection method.

As mentioned above, previous most of work concentrate on the wireless-aware network physical layer flow.Yet other performance parameter (as: transmission control protocol (TCP) flow etc.) of upper strata is the important factors that possible hinder the wireless aware technology too.TCP is in the employed most important host-host protocol in many popular internets are used, and comprises the application of WWW, FTP and some Streaming Medias.In addition, growing physical layer flow may cause the higher packets lost of physical layer, and this can have influence on the performance of TCP layer, uses thereby directly influence the user.Therefore, consider that in wireless-aware network the TCP performance is necessary.

Nearest studies show that: wireless network should be optimized rather than revise standard according to the TCP of standard TCP adapts to wireless network, yet the improvement to this field in the prior art but lacks, can't satisfy actual communication requirement, give further applying and develop and having brought many adverse effects of wireless communication technology.

Summary of the invention

The objective of the invention is to have overcome above-mentioned shortcoming of the prior art, the method that provide a kind of and can optimize TCP flow in the wireless-aware network, guarantee that the TCP flow obtains that raising, the processing procedure of essence is efficient and convenient, stable and reliable working performance, the scope of application improves the TCP transmission performance comparatively widely in the wireless-aware network.

In order to realize above-mentioned purpose, the method that improves the TCP transmission performance in the wireless-aware network of the present invention is as follows:

Improve the method for TCP transmission performance in this wireless-aware network, comprise main user and time user in the described wireless-aware network, its main feature is that described method may further comprise the steps:

(1) determines channel status space, state transition probability and the inferior user's of wireless-aware network system observation space;

(2) determine the inferior user's of wireless-aware network system combination motion space;

(3) determine immediate feedback and the general feedback of wireless-aware network system;

(4) calculate the best action policy collection of the inferior user in the wireless-aware network system according to described immediate feedback and general feedback;

(5) be defined as current TCP according to described best action policy collection and transmit selected optimum channel.

Improve channel status space, state transition probability and the inferior user's of the definite wireless-aware network system in the method for TCP transmission performance observation space in this wireless-aware network, may further comprise the steps:

(11) determine channel status space X in the wireless-aware network system according to following formula:

X＝{1，2，......，s-1，s}；

Wherein, every channel all is rayleigh fading channels, and all channels all have identical state space S; All channel integral body are one in the wireless-aware network system S ^LThe uniform markoff process of the discrete time of individual state, L is the total number of channels of wireless-aware network system, is specially:

X ^L＝{1，2，......，S ^L-1，S ^L}；

(12) determine the transition probability matrix T of wireless-aware network system according to following formula:

T＝S ^L×S ^L；

(13) determine that according to following formula the inferior user's of wireless-aware network system transducer observes the probability b of measured value θ _{J, θ} ^a:

$b_{j,\mathrm{\θ}}^a=\mathrm{Pr}\left\{\mathrm{\θ}\right|j,a\};$

Wherein, j is the channel status of current time slots, and a is the action of taking, and inferior user's sensors observe is θ to the observer state of a last time slot of this channel, θ _k∈ Θ, Θ={ γ ₁, γ ₂..., γ _s, γ _i＜γ _j,, $\&ForAll;i<j.$

Improve the inferior user's of the definite wireless-aware network system in the method for TCP transmission performance combination motion space in this wireless-aware network, be specially:

Determine that according to following formula time user is at the combination action a of time slot k in the wireless-aware network system _k:

a _k＝{a _s(k)，(ε(k)，δ(k))，a _a(k)，(m(k)，fr(k))}；

Wherein, a _s(k) be the detection action that time user continues judgement, a _s(k) ∈ 0,1 ..., L}, wherein 0 expression do not have to detect, 1 expression detects channel 1, L represents to detect channel L, (ε (k), δ (k)) ∈ A _{ε δ}Be the receiver operating curve A that determines which transducer operation is pointed to _{ε δ}Receiver operating curve for effectively pointing to has different definition for different transducers, and a _a(k) be the action of access channel, a _a(k) ∈ 0,1}, wherein 0 expression does not insert, 1 expression inserts, m (k) is employed physical layer modulation and encoding scheme, fr (k) is the data link layer frame size.

Improve immediate feedback and the general feedback of the definite wireless-aware network system in the method for TCP transmission performance in this wireless-aware network, may further comprise the steps:

(21) determine the immediate feedback R of time slot k in the wireless-aware network system according to following formula _k:

R _k＝B(cwnd，RTT _k，T _0，k，b，p(i _k，a _k))；

Wherein:

$B(\mathrm{cwnd},\mathrm{RTT},T_0,b,p)=\min (\frac{\mathrm{cwnd}}{\mathrm{RTT}},B(\mathrm{RTT},T_0,b,p));$

$B(\mathrm{RTT},T_0,b,p)\&ap;\frac{1}{\mathrm{RTT}\sqrt{\frac{2\mathrm{bp}}{3}}+T_0\min \left(\mathrm{1,3}\sqrt{\frac{3\mathrm{bp}}{8}}\right)p(1+32p^2)};$

B is the TCP flow, and cwnd is the extreme congestion window, and RTT is the turnaround time of TCP packets of information, and p is TCP packets lost probability, T ₀Be time-out time, b is the number of having received the TCP packets of information of confirming, RTT _kThe turnaround time of TCP packets of information during for time slot k, T _{0, k}Time-out time during for time slot k, p (i _k, a _k) be as system mode i when time slot k _kWith action a _kThe packets lost probability of TCP under the prerequisite;

(22) determine general feedback J in the wireless-aware network system according to following formula _μ:

$J_{\mathrm{\&mu;}}=E_{{\mathrm{\&mu;}}_s,{\mathrm{\&mu;}}_{\mathrm{\&epsiv;},\mathrm{\&delta;}},{\mathrm{\&mu;}}_a,{\mathrm{\&mu;}}_m,\mathrm{fr}}\left[\underset{k=1}{\overset{K}{\mathrm{\&Sigma;}}}{R}_k\right];$

Wherein, E is mathematic expectaion, μ _sBe the Channel Detection scheme, be used for detecting judgement a _s, μ _{ε, δ}Be the transducer operation scheme, expression is based on the spectral sensor design of the conflict tolerance probability of wireless-aware network system, and (ε, δ) ∈ A _{ε δ}, μ _aFor inserting the access scheme a of judgement _a, μ _mBe modulation and encoding scheme, μ _FrBe frame size a _FrScheme.

Improve in this wireless-aware network and calculate the best action policy collection of the inferior user in the wireless-aware network system according to described immediate feedback and general feedback in the method for TCP transmission performance, be specially:

Based on the linear programming algorithm according to described general feedback J _μCalculate the value function that has the greatest hope feedback in the limited motion space.

Adopted the method that improves the TCP transmission performance in the wireless-aware network of this invention, because wherein according to frequency spectrum detection, insert judgement, physical layer modulation and encoding scheme, and data link layer frame size and select the optimum channel of TCP stream in the wireless-aware network, thereby make the TCP flow obtain optimization, the modulation of physical layer and the frame size of encoding scheme and data link layer have wherein been considered, and consider low layer parameter simultaneously, thereby make the TCP flow obtain the raising of essence, not only processing procedure is efficient and convenient, and stable and reliable working performance, the scope of application is comparatively extensive.

Embodiment

In order more to be expressly understood technology contents of the present invention, describe in detail especially exemplified by following examples.

Improve the method for TCP transmission performance in this wireless-aware network, comprise main user and time user in the described wireless-aware network, wherein this method may further comprise the steps:

(1) determine channel status space, state transition probability and the inferior user's of wireless-aware network system observation space, may further comprise the steps:

(a) determine channel status space X in the wireless-aware network system according to following formula:

X＝{1，2，......，s-1，s}；

Wherein, every channel all is rayleigh fading channels, and all channels all have identical state space S; All channel integral body are one in the wireless-aware network system S ^LThe uniform markoff process of the discrete time of individual state, L is the total number of channels of wireless-aware network system, is specially:

X ^L＝{1，2，......，S ^L-1，S ^L}；

(b) determine the transition probability matrix T of wireless-aware network system according to following formula:

T＝S ^L×S ^L；

(c) determine that according to following formula the inferior user's of wireless-aware network system transducer observes the probability b of measured value θ _{J, θ} ^a:

$b_{j,\mathrm{\&theta;}}^a=\mathrm{Pr}\left\{\mathrm{\&theta;}\right|j,a\};$

Wherein, j is the channel status of current time slots, and a is the action of taking, and inferior user's sensors observe is θ to the observer state of a last time slot of this channel, θ _k∈ Θ, Θ={ γ ₁, γ ₂..., γ _s, γ _i＜γ _j,, $\&ForAll;i<j;$

(2) determine the inferior user's of wireless-aware network system combination motion space, be specially:

Determine in the wireless-aware network system that according to following formula time user is at the combination action ak of time slot k:

a _k＝{a _s(k)，(ε(k)，δ(k))，a _a(k)，(m(k)，fr(k))}；

Wherein, a _s(k) be the detection action that time user continues judgement, a _s(k) ∈ 0,1 ..., L}, wherein 0 expression do not have to detect, 1 expression detects channel l, L represents to detect channel L, (ε (k), δ (k)) ∈ A _{ε δ}Be the receiver operating curve that determines which transducer operation is pointed to, A _{ε δ}Receiver operating curve for effectively pointing to has different definition for different transducers, and a _a(k) be the action of access channel, a _a(k) ∈ 0,1}, wherein 0 expression does not insert, 1 expression inserts, m (k) is employed physical layer modulation and encoding scheme, fr (k) is the data link layer frame size; (3) determine immediate feedback and the general feedback of wireless-aware network system, may further comprise the steps:

(a) determine the immediate feedback R of time slot k in the wireless-aware network system according to following formula _k:

R _k＝B(cwnd，RTT _k，T _0，k，b，p(i _k，a _k))；

Wherein:

$B(\mathrm{cwnd},\mathrm{RTT},T_0,b,p)=\min (\frac{\mathrm{cwnd}}{\mathrm{RTT}},B(\mathrm{RTT},T_0,b,p));$

$B(\mathrm{RTT},T_0,b,p)\&ap;\frac{1}{\mathrm{RTT}\sqrt{\frac{2\mathrm{bp}}{3}}+T_0\min \left(\mathrm{1,3}\sqrt{\frac{3\mathrm{bp}}{8}}\right)p(1+32p^2)};$

B is the TCP flow, and cwnd is the extreme congestion window, and RTT is the turnaround time of TCP packets of information, and p is TCP packets lost probability, T ₀Be time-out time, b is the number of having received the TCP packets of information of confirming, RTT _kThe turnaround time of TCP packets of information during for time slot k, T _{0, k}Time-out time during for time slot k, p (i _k, a _k) be as system mode i when time slot k _kWith action a _kThe packets lost probability of TCP under the prerequisite;

(b) determine general feedback J in the wireless-aware network system according to following formula _μ:

$J_{\mathrm{\&mu;}}=E_{{\mathrm{\&mu;}}_s,{\mathrm{\&mu;}}_{\mathrm{\&epsiv;},\mathrm{\&delta;}},{\mathrm{\&mu;}}_a,{\mathrm{\&mu;}}_m,\mathrm{fr}}\left[\underset{k=1}{\overset{K}{\mathrm{\&Sigma;}}}{R}_k\right];$

Wherein, E is mathematic expectaion, μ _sBe the Channel Detection scheme, be used for detecting judgement a _s, μ _{ε, δ}Be the transducer operation scheme, expression is based on the spectral sensor design of the conflict tolerance probability of wireless-aware network system, and (ε, δ) ∈ A _{ε δ}, μ _aFor inserting the access scheme a of judgement _a, μ _mBe modulation and encoding scheme, μ _FrBe frame size a _FrScheme;

(4) calculate the best action policy collection of the inferior user in the wireless-aware network system according to described immediate feedback and general feedback, be specially:

Based on the linear programming algorithm according to described general feedback J _μCalculate the value function that has the greatest hope feedback in the limited motion space;

(5) be defined as current TCP according to described best action policy collection and transmit selected optimum channel.

In the middle of reality is used, exist under a plurality of scenes that obtain channel, the present invention has studied the channel detection method an of the best.(for main user, because main user and time user are arranged in the wireless-aware network, main user sends data to their corresponding destination by a master network to inferior like this user; On the other hand, inferior user obtains to insert by a secondary network) just can find a free and good channel to make the transmission rate maximization of physical layer.

TCP about the wireless-aware network employed model that circulates is at first described among the present invention.

(1) TCP discharge model

Transmission control protocol provides more convenient compared to User Datagram Protoco (UDP), mistake recovery, flow control and reliability.Up to now, there is the TCP algorithm of many raising TCP performances to be carried.The static properties of TCP stream is representative with the flow, and it is a key factor of indication TCP performance.A following description of simple analytical model of TCP flow:

$B(\mathrm{RTT},T_0,b,p)\&ap;\frac{1}{\mathrm{RTT}\sqrt{\frac{2\mathrm{bp}}{3}}+T_0\min \left(\mathrm{1,3}\sqrt{\frac{3\mathrm{bp}}{8}}\right)p(1+32p^2)}......\left(1\right)$

Here p is packets of information loss rate, and RTT is a turnaround time, T ₀Be a time-out time, b is the number (representative value of b is 2) of the packets of information of having received that affirmation (ACK) is identified.In addition, because the TCP flow is also limited by extreme congestion window cwnd, TCP flow B is:

$B(\mathrm{cwnd},\mathrm{RTT},T_0,b,p)=\min (\frac{\mathrm{cwnd}}{\mathrm{RTT}},B(\mathrm{RTT},T_0,b,p))......\left(2\right)$

Furtherly, be L to a length _TCPThe TCP packets of information, it will be divided into a plurality of littler frames in data link layer.The length of supposing a frame head is L _Frh, and the frame number of each TCP packets of information is N _FrSo, can obtain a frame length $L_{\mathrm{fr}}=\frac{L_{\mathrm{TCP}}}{N_{\mathrm{fr}}}+L_{\mathrm{frh}}.$ So, frame error ratio F _eJust can be calculated.

$F_e=1-{(1-\mathrm{BER})}^{L_{\mathrm{fr}}}......\left(3\right)$

In the ARQ scheme, the transmission of frame only just is counted as merit during less than maximum at number of retransmissions.Therefore, if maximum number of retransmission is N _Retran, the frame error ratio of ARQ is

Similarly, for packets of information, packet error rate P _eCan obtain by following equation:

$P_e=1-{(1-F_e^{N_{\mathrm{retran}}+1})}^{N_{\mathrm{fr}}}......\left(4\right)$

According to a basic ARQ agreement, when corresponding terminal was received a frame, each ACK frame can return to the sender.Therefore, the turnaround time of a TCP packets of information is probably as follows:

$\mathrm{RTT}=2\&CenterDot;T_{\mathrm{wired}}+(\frac{L_{\mathrm{fr}}}{r}\&CenterDot;(N_{\mathrm{ave}}+1)+\frac{L_{\mathrm{ack}}}{r})\&CenterDot;N_{\mathrm{fr}}......\left(5\right)$

Here L _FrAnd L _AckBe the length of a frame and ACK data that frame comprises.N _AveBe the average repeat time of a frame, its computing formula is as follows:

$N_{\mathrm{ave}}=\frac{1-F_e^{N_{\mathrm{retran}}+1}}{1-F_e}-F_e^{N_{\mathrm{retran}}+1}......\left(6\right)$

From top equation, can see in the wireless-aware network that physical layer or data link layer design parameter can be influential to the TCP flow.

(2) system model

We suppose to have in the wireless-aware network main using and time user.Main user sends data to its corresponding destination by a master network, and on the other hand, inferior user obtains to insert by a secondary network.Main user and time user share one section frequency spectrum that L bar wireless channel is arranged, and the bandwidth of every channel is W (l), 1≤l≤L, and the time is divided into the time slot of equal length T, and time slot k refers to discrete time [kT, (k+1) * T] at interval.In addition, the present invention supposes that system transfers to a new state when each time slot begins.

Wireless channel in the wireless-aware network not only bears Rayleigh fading under idle condition also can run into the situation that main user occupies.By and large, a FSMC model is to form by the scope of the SNR that receives is divided into discrete levels.Each level is corresponding with a markovian state.Suppose that i and r represent instantaneous channel status and channel gain.When a channel was in state i, corresponding channel gain was r _i, r _i≤ r≤r _I+1, 1≤i≤S-1.In addition, main subscriber busy condition also is at random, and is modeled as a state in the Markov Chain.In model of the present invention, wherein make i=1 represent busy condition.S-state Markov channel model is to carry out complete description by the static distribution of every channel status i, and it is represented as p (i).When each time slot begins, the probability tables that is transformed into state j from state i be shown p (i, j), 1≤i, j≤S.The information of given decline process and master network use, just can draw static distribution p (i) and channel status transition probability p (i, j).

The present invention solves the problem that the TCP performance improves in the wireless-aware network by following process:

(1) state space, transition probability and observation space

In each time slot, system mode be with main user network use and channel condition information as feature.Suppose that X represents the channel status space of a channel, X={1,2 ..., S-1, S}.Therefore, the system of L bar channel is modeled as one S ^LThe uniform markoff process of the discrete time of state is expressed as X ^L=1,2 ..., S ^L-1, S ^L.In actual applications, the channel status transfer is incoherent with the action of taking.This is a special P OMDP model.The state transition probability of system is S ^L* S ^LMatrix T.

The measured value that inferior user obtains is the result of Channel Detection, θ _k∈ Θ, Θ={ γ ₁(busy condition), γ ₂..., γ _s, γ _i≤ γ _j, $\&ForAll;i<j.$

Because channel estimation error and some detect mistake, inferior user can't intactly obtain channel condition information at each time slot.Suppose $b_{j,\mathrm{\&theta;}}^a=\mathrm{Pr}\left\{\mathrm{\&theta;}\right|j,a\}$ Expression when channel status is j when at this time slot sensors observe to the probability of θ and on the observer state of an action (at last time slot) be θ, suppose that channel status is j and has taked action a.

(2) motion space

When each time slot k began, inferior user will continue judgement and whether detect a _s(k) ∈ 0 (do not have detect), 1 (detecting channel 1) ..., L (detecting channel L) }, the receiver operating curve (ROC) that determines which transducer operation to point to bends to (ε (k), δ (k)) ∈ A _{ε δ}, A _{ε δ}Be effectively to point to the ROC curve, access channel a whether _a(k) ∈ { 0 (not inserting), 1 (access) }, and the physical layer modulation of using and encoding scheme are fr (k) as m (k) and data link layer frame size.Therefore, be shown at time slot k combination action schedule:

a _k＝{a _s(k)，(ε(k)，δ(k))，a _a(k)，(m(k)，fr(k))}。

(3) feedback and scheme

Wherein, the present invention regards the TCP flow as the immediate feedback of our equation.Immediate feedback during time slot k is defined as:

R _k＝B(cwnd，RTT _k，T _0，k，b，p(i _k，a _k))......(7)

RTT _kBe two-way time, T _{0, k}Be time-out time, b is by the packets of information number of receiving that affirmation (ACK) is identified, p (i _k, a _k) be expressed as that system is in state i when time slot k _kAnd action is a _kThe time the packets lost probability.

POMDP can be expressed as in the whole feedback that K time slot expectation obtains:

$J_{\mathrm{\&mu;}}=E_{{\mathrm{\&mu;}}_s,{\mathrm{\&mu;}}_{\mathrm{\&epsiv;},\mathrm{\&delta;}},{\mathrm{\&mu;}}_a,{\mathrm{\&mu;}}_m,\mathrm{fr}}\left[\underset{k=1}{\overset{K}{\mathrm{\&Sigma;}}}{R}_k\right]......\left(8\right)$

Wherein, μ _sBe a kind of Channel Detection scheme, it is used for representing detection judgement a _s, μ _{ε δ}Represent a kind of transducer operation scheme, it is used for representing a kind of spectral sensor design (ε, δ) ∈ A of the conflict tolerance probability based on system _{ε δ}, μ _aBe a kind of access scheme a that represents to insert judgement _a, μ _mAnd μ _FrExpression is modulated and coding (AMC) scheme and frame size scheme respectively, and that their are described is modulation and encoding scheme and frame size a _Fr

(4) solve the POMDP problem by value function

Can solve the value function problem of the greatest hope feedback of the limited motion space of expression by Linear Programming Techniques.Concrete ins and outs see also following document:

W.Lovejoy，”A?survey?of?algorithmic?methods?for?partially?observed?Markov?decision?processes”，Ann，of?Oper.Res.，vol.28，no.1，pp.47-66，1991。

About the background technology content that the present invention is correlated with, can also consult following document:

J.Padhye，V.Firoiu，D.F.Towsley，and?J.F.Kurose，”Modeling?TCP?Reno?performance：A?simplemodel?and?its?empirical?validation，”IEEE/ACM?Trans.Newt.，vol.8，no.2，pp.133-145，2000。

Adopted the method that improves the TCP transmission performance in the above-mentioned wireless-aware network, because wherein according to frequency spectrum detection, insert judgement, physical layer modulation and encoding scheme, and data link layer frame size and select the optimum channel of TCP stream in the wireless-aware network, thereby make the TCP flow obtain raising, the modulation of physical layer and the frame size of encoding scheme and data link layer have wherein been considered, and consider low layer parameter simultaneously, thereby make the TCP flow obtain the raising of essence, not only processing procedure is efficient and convenient, and stable and reliable working performance, the scope of application is comparatively extensive.

In this specification, the present invention is described with reference to its certain embodiments.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 (5)

1. improve the method for TCP transmission performance in the wireless-aware network, comprise main user and time user in the described wireless-aware network, it is characterized in that described method may further comprise the steps:

(1) determines channel status space, state transition probability and the inferior user's of wireless-aware network system observation space;

(2) determine the inferior user's of wireless-aware network system combination motion space;

(3) determine immediate feedback and the general feedback of wireless-aware network system;

(4) calculate the best action policy collection of the inferior user in the wireless-aware network system according to described immediate feedback and general feedback;

(5) be defined as current TCP according to described best action policy collection and transmit selected optimum channel.

2. improve the method for TCP transmission performance in the wireless-aware network according to claim 1, it is characterized in that, channel status space, state transition probability and the inferior user's of described definite wireless-aware network system observation space may further comprise the steps:

(11) determine channel status space X in the wireless-aware network system according to following formula:

X={1，2，……，S－1，S}；

Wherein, every channel all is rayleigh fading channels, and all channels all have identical state space S; All channel integral body are one in the wireless-aware network system S ^LThe uniform markoff process of the discrete time of individual state, L is the total number of channels of wireless-aware network system, is specially:

X ^L＝{1，2，……，S ^L－1，S ^L}；

(12) determine the transition probability matrix T of wireless-aware network system according to following formula:

T＝S ^L×S ^L；

(13) determine that according to following formula the inferior user's of wireless-aware network system transducer observes the probability of measured value θ

$b_{j,\mathrm{\&theta;}}^a=\mathrm{Pr}\left\{\mathrm{\&theta;}\right|j,a\};$

Wherein, j is the channel status of current time slots, and a is the action of taking, and inferior user's sensors observe is θ to the observer state of a last time slot of this channel, θ _k∈ Θ, Θ={ γ ₁, γ ₂..., γ _s, γ _i＜γ _j,

3. improve the method for TCP transmission performance in the wireless-aware network according to claim 2, it is characterized in that, the inferior user's of described definite wireless-aware network system combination motion space is specially:

Determine that according to following formula time user is at the combination action a of time slot k in the wireless-aware network system _k:

a _k＝{a _s(k),(ε(k),δ(k)),a _a(k),(m(k),fr(k))}；

Wherein, a _s(k) be the detection action that time user continues judgement, a _s(k) ∈ 0,1 ..., L}, wherein 0 expression does not have detection, and 1 expression detects channel 1, and L represents to detect channel L, (ε (k), δ (k)) ∈ A _{ε δ}Be the receiver operating curve that determines which transducer operation is pointed to, A _{ε δ}Be the receiver operating curve that effectively points to, and a _a(k) be the action of access channel, a _a(k) ∈ 0,1}, wherein 0 expression does not insert, 1 expression inserts, m (k) is employed physical layer modulation and encoding scheme, fr (k) is the data link layer frame size.

4. improve the method for TCP transmission performance in the wireless-aware network according to claim 3, it is characterized in that, immediate feedback and the general feedback of described definite wireless-aware network system may further comprise the steps:

(21) determine the immediate feedback R of time slot k in the wireless-aware network system according to following formula _k:

R _k＝B(cwnd,RTT _k,T _0,k,b,p(i _k,a _k))；

Wherein:

$B(\mathrm{cwnd},\mathrm{RTT},T_0,b,p)=\min (\frac{\mathrm{cwnd}}{\mathrm{RTT}},B(\mathrm{RTT},T_0,b,p));$

$B(\mathrm{RTT},T_0,b,p)\&ap;\frac{1}{\mathrm{RTT}\sqrt{\frac{2\mathrm{bp}}{3}}{+T}_0\min \left(\mathrm{1,3}\sqrt{\frac{3\mathrm{bp}}{8}}\right)p(1+32p^2)};$

B is the TCP flow, and cwnd is the extreme congestion window, and RTT is the turnaround time of TCP packets of information, and p is TCP packets lost probability, T ₀Be time-out time, b is the number of having received the TCP packets of information of confirming, RTT _kThe turnaround time of TCP packets of information during for time slot k, T _{0, k}Time-out time during for time slot k, p (i _k, a _k) be as system mode i when time slot k _kWith action a _kThe packets lost probability of TCP under the prerequisite;

(22) determine general feedback J in the wireless-aware network system according to following formula _μ:

$J_{\mathrm{\&mu;}}=E_{{\mathrm{\&mu;}}_s,{\mathrm{\&mu;}}_{\mathrm{\&epsiv;},\mathrm{\&delta;},}{\mathrm{\&mu;}}_a,{\mathrm{\&mu;}}_m,\mathrm{fr}}\left[\underset{k=1}{\overset{K}{\mathrm{\&Sigma;}}}{R}_k\right];$

Wherein, E is mathematic expectaion, μ _sBe the Channel Detection scheme, be used for detecting judgement a _s, μ _{ε, δ}Be the transducer operation scheme, expression is based on the spectral sensor design of the conflict tolerance probability of wireless-aware network system, and (ε, δ) ∈ A _{ε δ}, μ _aFor inserting the access scheme a of judgement _a, μ _mBe modulation and encoding scheme, μ _FrBe frame size a _FrScheme.

5. improve the method for TCP transmission performance in the wireless-aware network according to claim 4, it is characterized in that, describedly calculate the best action policy collection of the inferior user in the wireless-aware network system according to described immediate feedback and general feedback, be specially:

Based on the linear programming algorithm according to described general feedback J _μCalculate the value function that has the greatest hope feedback in the limited motion space.