CN102761944A - Power saving method using sleep mode in IEEE (Institute of Electrical and Electronic Engineers) 802.16e - Google Patents

Abstract

The invention provides a power saving method using a sleep mode in IEEE (Institute of Electrical and Electronic Engineers) 802.16e, belonging to the field of wireless information transmission. Counters are arranged at the both sides of a base station and a terminal simultaneously; and numerical values of the counters are added with one when the terminal receives or sends data for one time in a monitoring window of a sleep period. The service busy degree of the current terminal can be represented according to the numerical values of the counters, so that whether the terminal state is changed from the sleep state to an ordinary state or not is controlled according to the recording values of the counters. A software design process provided by the invention is simple and easy to implement; unnecessary state transition is reduced by adding a group of the counters, so that the time of the terminal at the sleep mode is prolonged. Furthermore, the energy consumption of the terminal is reduced, and the terminal standby time is prolonged.

Description

The electricity saving method of IEEE802.16e park mode

Technical field

The invention belongs to the wireless messages transmission field, be applicable to the wireless communication system that adopts the IEEE802.16e standard.

Background technology

Wireless access wide band technology standard IEEE 802.16e supports the multimedia service of two-forty, high mobility.Fill up the blank between the cellular communication system of WLAN and high mobility of two-forty, had very big market potential.Portable terminal is mainly battery-powered in the system, is the major issue that the IEEE802.16e system applies faces so how to reduce the energy consumption of portable terminal.

To this problem, the IEEE802.16e standard definition park mode, under the situation of low traffic, get into dormancy period after terminal and the base station negotiate.Be in the turn-on time that the terminal of park mode will temporarily interrupt reducing base band and radio circuit to reach the purpose that reduces energy consumption with getting in touch of base station.

At present, according to the park mode of stipulating in the standard, be in the terminal of park mode, when base station transmission prompting had the signaling of downlink data, the terminal need be withdrawed from park mode and get into the normal mode transceive data.And the energy consumption of portable terminal depends on the total time of terminal connection base band and radio circuit.Frequent switches between general mode and park mode, can energization consumption.And each dormancy period sends the signaling whether prompting has downlink data, has increased the base station interface-free resources and has taken.Its in fact, dormancy period is made up of sleep window and audit window.At audit window, the terminal can be as the normal mode downlink data receiving.During low traffic, utilize audit window to carry out the reception of data like this, processing speed can satisfy the speed of data arrives, promptly can avoid the frequent switching of terminal between general mode and listen mode.And when data volume was big, the terminal can be continuously in a plurality of audit window deal with data.Can utilize this characteristic, through in base station and terminal counter CBS is set respectively, CMS adds up that the dormancy period at data arrives terminal number is arranged continuously.When statistical value surpassed predefined threshold value, characterizing current terminal had than high traffic.The terminal changes the normal sending and receiving that general mode carries out data over to from resting state automatically.Park mode algorithm in the standard, the present invention proposes the signaling consumption that electricity saving method has not only reduced the terminal; Simultaneously can be with the effect that reaches province's electric weight 30% through the threshold value that counter rationally is set; And implementation method simply is easy to engineering construction.

[1]Enjie?Liu,Jie?Zhang,Weili?Ren.A?Counter-Driven?Adaptive?Sleep?Mode?Scheme?for?802.16e?Networks.IEEE73rd?Vehicular?Technology?Conf.(VTC2011-Spring),Budapest,Hungary,May,2011

Summary of the invention

The object of the present invention is to provide a kind of electricity saving method that is easy to Project Realization and can increases the IEEE802.16e park mode of terminal energy-efficient.

The thought of the park mode of standard IEEE 802.16e is: the energy consumption at terminal depends primarily on total duration of base band and radio circuit conducting.The terminal base band and the radio circuit that are in general mode are in conducting state always, and energy consumption is excessive.For the energy consumption and the reduction that reduce the terminal park mode has been stipulated in the use of serving BS interface-free resources in the IEEE802.16e standard.Park mode is that getting in touch of interruption and base station temporarily closed with base band and radio circuit at low traffic period in the terminal.Wherein power saving class I is applicable to non-real-time polling service and the data service of doing one's best, and such connection can be stood certain transfer of data time-delay.The terminal of employing power saving class I can initiatively be sent sleep request message and got into park mode to base station requests.Comprise parameter in the request message: initial sleep window (sleep window 1 among Fig. 2 (a)), the maximum sleep window, audit window begins frame number with first sleep window.The base station receives that the request message at terminal replys response message parameter is confirmed.The terminal begins frame number entering park mode in first sleep window of identified in response messages afterwards.Under park mode, there are two states at the terminal: resting state and listening state.The terminal is a down state in sleep window (corresponding resting state), and the base station can't establish a communications link with the terminal.One or more hardware device is closed at the terminal in this time period, to reach the power saving purpose.After each sleep window finishes, have the audit window (corresponding listening state) of a certain time length, be in the downstream message that upstate can receive the base station in the terminal in the time at audit window.Sleep window and audit window alternately occur, and a sleep window and an audit window are formed a dormancy period.The terminal receives at each audit window and comes from the flow prompting message that send the base station, and this message is used for indicating the base station whether the downlink data that sends to the terminal is arranged.If the flow prompting message in the flow prompting message is actively, prove that the base station has downlink data to send to the terminal, the terminal will be withdrawed from park mode and get into general mode so, carry out the transmitting-receiving of data.If the flow prompting message in the flow prompting message is passive, then free of data business in base station sends to the terminal, and the big young pathbreaker of so next sleep window is Last twice, but can not surpass the maximum sleep length of window of appointment.Surpass the maximum sleep window if increase, sleep window so afterwards will keep this value constant.Whole sleep procedure is shown in Fig. 2 (a) figure.

The main thought of park mode electricity saving method that the present invention proposes is: prescribed terminal can receive the down management message that send the base station at the audit window of dormancy period in the standard, and this is base band and radio circuit conducting constantly, the beginning consumed energy.Can utilize so to receive or to send data the time period, replace the flow prompting message.Be in the terminal data traffic carrying capacity of dormancy period under the low traffic situation when fewer, this time period of audit window promptly capable of using, data service disposed, and need not to get into general mode from park mode.If the terminal has mass data professional, can data processing be distributed in a plurality of audit windows.If therefore the continuous a plurality of dormancy periods in terminal transmit data, then should withdraw from park mode entering general mode and carry out data processing.Based on this thought, after the terminal got into park mode, base station and terminal be enabling counting device CBS and CMS simultaneously, and when the audit window reception data of terminal at certain dormancy period, Counter Value adds 1.Requiring has a plurality of dormancy periods that data arrives is arranged continuously, and the terminal will be withdrawed from park mode and get into general mode.The detailed process of park mode electricity saving method is described shown in Fig. 2 (b).

Need threshold value m be set to counter and judge that what dormancy period continuous data transfers are judged to be busy period.The size of m value will have influence on the energy-efficient rate.The m value is big more, and the terminal is in that the duration of park mode is long more, and the electricity-saving rate is big more, but the time delay of corresponding transfer of data also can correspondingly increase.The concrete computational methods of m value are following:

At first the park mode electricity saving method is set up analytical model, model such as Fig. 3.

The m value is the threshold value of counter among the figure.α _n(1≤n≤max) expression gets into the probability of next dormancy period n+1 from dormancy period n.α _NExpression is from the probability of general mode entering park mode, β _n(m≤n≤max) expression gets into the probability of general mode from dormancy period n.Each dormancy period is made up of an audit window and a sleep window.Audit window length is definite value L, and initial sleep window size is t ₁, the size of the sleep window of n the dormancy period of regulation that calculates according to the relevant sleep window of agreement IEEE802.16E is:

$t_n=\left\{\begin{array}{cc}{2}^{n-1}{\mathrm{<figure-callout\; id="1"\; label="t"\; filenames="HDA00001799644400031.png"\; state="\{\{state\}\}">t</figure-callout>}}_1,& 2^{n-1}{\mathrm{<figure-callout\; id="1"\; label="t"\; filenames="HDA00001799644400031.png"\; state="\{\{state\}\}">t</figure-callout>}}_1<t_{\max }\\ t_{\max },& 2^{n-1}{\mathrm{<figure-callout\; id="1"\; label="t"\; filenames="HDA00001799644400031.png"\; state="\{\{state\}\}">t</figure-callout>}}_1\&GreaterEqual;t_{\max }\end{array}\right.---\left(1\right)$

It is the Poisson process of λ (frame/second) that access rate is obeyed in the transmission of terminal data frame.So, the probability that does not have transfer of data in the time t according to being defined in of Poisson formula is e ^{-λ t}, the corresponding probability that transfer of data is arranged is 1-e ^{-λ t}(total time of 1≤n≤max) is sleep window duration t to dormancy period n _nWith audit window duration L with.There is the probability of transfer of data to do at dormancy period n so

If setting the counter gate limit value is m, β when m≤n≤max-1 then _nPhysical significance is: dormancy period n; Before; M-1 the dormancy period that begins from dormancy period n-m+1 all has transfer of data, and dormancy period n also has transfer of data, and promptly m dormancy period has transfer of data then to enter into general mode after n dormancy period continuously.Continuously m dormancy period have transfer of data probability is

as n < during m; No matter dormancy period has or not transfer of data; All can not satisfy a continuous m dormancy period gets into general mode by transfer of data requirement, so probability is 0.When n=max, owing to there is not next dormancy period, can only get into general mode from park mode, so β _MaxExpression is by the probability of maximum sleep window entering general mode, and its value equals 1.

${\mathrm{\&beta;}}_n=\left\{\begin{array}{cc}0,& (n<m)\\ \underset{i=n-m+1}{\overset{n}{\mathrm{\&Pi;}}}(1-e^{-\mathrm{\&lambda;}(t_i+L)})& (m\&le;n\&le;\max -1)\\ 1,& (n=\max )\end{array}\right.---\left(2\right)$

If do not satisfy the condition that gets into general mode, will get into dormancy period n+1 from dormancy period n so at dormancy period n.Use α _n(expression of 1≤n≤max) from dormancy period n get into next dormancy period probability.As 1≤n<during m, no matter have or not transfer of data all can get into next dormancy period, so α _nValue be 1.When m≤n≤max-1, this moment, the terminal might get into next dormancy period, also might satisfy the condition that gets into general mode, therefore get into next dormancy period probability equal total probable value 1 and deduct the probability that gets into general mode, i.e. 1-β _nUse α _NThe expression general mode gets into the probability of initial dormancy period 1, get into dormancy period owing to locate the terminal of general mode through exchange of signaling, so its value is 1.

${\mathrm{\&alpha;}}_n=\left\{\begin{array}{cc}1,& (1\&le;n<m)\\ 1-{\mathrm{\&beta;}}_n,& (m\&le;n\&le;\max -1)\end{array}\right.---\left(3\right)$

β _n, α _n, α _NBe the state transition probability between each dormancy period of terminal and the general mode, be in the probability π of each dormancy period in the time of can obtaining t → ∞ so _n(1≤n≤max) and the probability π that is in general mode _NComputing formula be:

$\left\{\begin{array}{cc}& \\ {\mathrm{\&pi;}}_{n+1}={\mathrm{\&alpha;}}_n{\mathrm{\&pi;}}_n,(1\&le;n<\max )& \left(a\right)\\ {\mathrm{\&pi;}}_1={\mathrm{\&alpha;}}_N{\mathrm{\&pi;}}_N& \left(b\right)\\ {\mathrm{\&pi;}}_N=\underset{i=m}{\overset{\max }{\mathrm{\&Sigma;}}}{\mathrm{\&beta;}}_i{\mathrm{\&pi;}}_i& \left(c\right)\end{array}\right.---\left(4\right)$

(a) physical significance of formula is as (1≤n<max) time, the probability of dormancy period n entering dormancy period n+1 equals to obtain the probability π of dormancy period n _nMultiply by the probability α that gets into dormancy period n+1 by dormancy period n _n(b) physical significance is that the probability of obtaining dormancy period 1 is the probability π that is in general mode _NGet into park mode probability α with general mode _NProduct.(c) the expression probability of obtaining general mode equals the probability sum that each dormancy period gets into general mode

The probability of each dormancy period entering general mode equals to be in the probability π of each dormancy period _iGet into general mode probability β with this dormancy period _iProduct.

With α _n, α _N, β _nThe formula after simplifying of bringing formula (4) into does

$\left\{\begin{array}{c}{\mathrm{\&pi;}}_N={\mathrm{\&pi;}}_1=\&CenterDot;\&CenterDot;\&CenterDot;={\mathrm{\&pi;}}_m\\ {\mathrm{\&pi;}}_{n+1}={\mathrm{\&pi;}}_n{\mathrm{\&alpha;}}_n,(m\&le;n<\max )\\ {\mathrm{\&pi;}}_N=\underset{i=m}{\overset{\max }{\mathrm{\&Sigma;}}}{\mathrm{\&beta;}}_i{\mathrm{\&pi;}}_i\end{array}\right.---\left(5\right)$

In conjunction with formula

${\mathrm{\&pi;}}_N=\underset{i=1}{\overset{\max }{\mathrm{\&Sigma;}}}{\mathrm{\&pi;}}_i=1---\left(6\right)$

Can try to achieve the probability π of dormancy period _n(1≤n≤max) and the probability π that is in general mode _NThe energy consumption power at sleep window terminal is E _S, audit window energy consumption power is E _RxThe energy consumption of a dormancy period is divided into two parts, the energy consumption (L*E of the energy consumption of audit window and sleep window _Rx+ t _k* E _S).If obtain dormancy week i, before the total energy consumption in terminal should be the summation of i dormancy period energy consumption promptly so the average energy consumption value should be the total energy consumption product of the probability of obtaining each dormancy period and this dormancy period and:

$E=\underset{i=1}{\overset{\max }{\mathrm{\&Sigma;}}}\left(\underset{k=1}{\overset{i}{\mathrm{\&Sigma;}}}(L*E_{\mathrm{rx}}+t_k*E_S)\right)*{\mathrm{\&pi;}}_i---\left(7\right)$

Consider the randomness of Poisson distribution, the due in of tentation data frame in the same dormant stage obeyed evenly and distributed, and obtains average delay and is:

$E\left(t\right)=\underset{i=1}{\overset{\max }{\mathrm{\&Sigma;}}}\left(\frac{L+t_i}{2}\right)*{\mathrm{\&pi;}}_i---\left(8\right)$

Show that based on lot of experiment results along with the increase of m value, the average energy consumption value is more little, but because the restriction of delaying time for data in the terminal, m value long time delay more is long more.So can not be with the unconfined maximum of m value.Experimental result shows that energy-efficient is linear growth when m increased gradually before max/3.Behind max/3, energy-efficient is little for max/3 increases than the m value, and time delay is and still is linear growth.Therefore, the value of m value should be (, max/3-2, the integer value in max/3+2) interval, the average energy consumption and the average delay that calculate according to formula (7), (8).General m value is a plurality of, for example m ₁, m ₂... M _I-1, m _i, m _I+1Appropriate m value must be able to make

$\mathrm{\&eta;}=\frac{(E_{m_{i-1}}-E_{m_i})/E_{m_{i-1}}}{(E_{m_i}\left(t\right)-E_{m_{i-1}}\left(t\right))/E_{m_{i-1}}\left(t\right)}---\left(9\right)$

Value reach maximum, the physical significance of formula (9) is: energy-efficient reaches maximum, and time delay increases minimum.The m value of this moment is required m value.

Particularly, the implementation step of method proposed by the invention is following, and is as shown in Figure 1.

The first step: two counters are provided with threshold value; 101

Second step: the terminal through and the base station between exchange of signaling get into park mode; 102

The 3rd step: get into resting state, terminal and base station initiated counter CMS, CBS statistics have the dormancy period number of transfer of data continuously.If counting is interrupted then two counters put 0 simultaneously, restart counting; 103

The 4th step: whether the detection counter record value surpasses threshold value; 104

The 5th step: counter does not surpass the threshold value terminal to be continued to keep park mode, repeats for the 4th step; 105

The 6th step: counter surpasses threshold value, and the terminal is withdrawed from park mode and got into general mode.106

The electricity saving method of park mode can reduce the switching of low traffic terminal in period between general mode and park mode, reduces signaling consumption.And it only need be provided with a set of counters in base station and both sides, terminal, is easy in engineering, realize.

Description of drawings

The practical implementation step of Fig. 1 park mode electricity saving method.

Fig. 2 (a) standard sleep mode method process sketch map.

Fig. 2 (b) and park mode electricity saving method process sketch map.

Fig. 3 park mode power savings algorithms analytical model

Embodiment

At first, calculate based on the computational methods of above-mentioned m value and make the maximum pairing m value of power-saving rate.The threshold value of counter CBS, CMS is set to m.

Then, the terminal is sent the sleep request message request to the base station and is got into resting state.The terminal receives that the response message that send the base station confirms dormancy parameter, begins the frame number place in first sleep window and gets into park mode.Base station and terminal start timer CBS and CMS simultaneously simultaneously.

When the terminal adds 1 two counters the time when certain dormancy period has data service.When continuous a plurality of dormancy periods all have data arrives, when the count value of counter surpassed threshold value m, the terminal was withdrawed from park mode and is got into general mode.If counting interruption then two counters puts 0, restart counting, surpass threshold value up to the continuous counter value, get into general mode from park mode.

New electricity saving method can avoid the terminal between general mode and park mode, frequently to switch, and increased the duration that the terminal is in park mode; Owing to cancelled the transmission of flow prompting message, reached the purpose that reduces signaling consumption; Only one set of counters is set and is easy to Project Realization in terminal and both sides, base station.

For example:

L=5ms, t ₁=10ms, t _Max=10.24s, λ=30 (λ representes the frame number of incoming terminal each second, and a frame is 5 milliseconds, thus in the actual measuring and calculating value of λ can be in 0 ~ 200 value arbitrarily, but because to be in the terminal ordinary business practice amount of park mode lower, suggestion is in 0 ~ 50 value), E _S=10mW, E _Rx=1W. calculates to such an extent that dormancy period is 1 ~ 11 according to formula (1), t ₁=10ms, t ₂=20ms, t ₃=40ms, t ₄=80ms, t ₅=160ms, t ₆=320ms, t ₇=640ms, t ₈=1280ms, t ₉=2560ms, t ₁₀=5120ms, t ₁₁=10240ms, totally 11 dormancy periods.According to interval (max/3-2, max/3+2) in the principle of value, the m value is decided to be 2,3,4,5.For example apply mechanically above-mentioned formula (2) during m=3

${\mathrm{\&beta;}}_n=\left\{\begin{array}{cc}0,& (n<3)\\ \underset{i=n-2}{\overset{n}{\mathrm{\&Pi;}}}(1-e^{-\mathrm{\&lambda;}(t_i+L)})& (3\&le;n\&le;10)\\ 1,& (n=11)\end{array}\right.$

Applying mechanically formula (3) obtains:

${\mathrm{\&alpha;}}_n=\left\{\begin{array}{cc}1,& (1\&le;n<3)\\ 1-{\mathrm{\&beta;}}_n,& (3\&le;n\&le;10)\end{array}\right.$

α _N=1;

With β _n, α _n, α _NBring formula (5) into

$\left\{\begin{array}{c}{\mathrm{\&pi;}}_N={\mathrm{\&pi;}}_1={\mathrm{\&pi;}}_2={\mathrm{\&pi;}}_3\\ {\mathrm{\&pi;}}_n={\mathrm{\&pi;}}_{n-1}{\mathrm{\&alpha;}}_{n-1},(3<n\&le;11)\\ {\mathrm{\&pi;}}_N=\underset{i=m}{\overset{10}{\mathrm{\&Sigma;}}}{\mathrm{\&beta;}}_i{\mathrm{\&pi;}}_i+{\mathrm{\&pi;}}_{11}\end{array}\right.$

In conjunction with formula

Can be regarded as the probability π of dormancy period _n(1≤n≤11) and the probability π that is in general mode _N

With calculate value bring formula into $E=\underset{i=1}{\overset{11}{\mathrm{\&Sigma;}}}\left(\underset{k=1}{\overset{i}{\mathrm{\&Sigma;}}}(L*E_{\mathrm{Rx}}+t_i*E_S)\right)*{\mathrm{\&pi;}}_i$ With $E\left(t\right)=\underset{i=1}{\overset{11}{\mathrm{\&Sigma;}}}\frac{L+t_i}{2}*{\mathrm{\&pi;}}_i$

E=0.405W when recording data m=3, E (t)=29ms;

With the adjustment m=2 the time E=0.462W, E (t)=16.5ms;

E=0.365W during m=4, E (t)=55ms;

E=0.335W during m=5, E (t)=108ms;

Can see that by above data reduced the 0.06W time delay has increased 13.5ms. and apply mechanically formula (9) and obtain from m=2 to the m=3 energy consumption

${\mathrm{\&eta;}}_1=\frac{0.06W/0.462W}{13.5\mathrm{ms}/16.5\mathrm{ms}}=0.158$

Reduce the 0.04W time delay from m=3 to the m=4 energy consumption and increased 26ms.

${\mathrm{\&eta;}}_2=\frac{0.04W/0.405W}{26\mathrm{ms}/29\mathrm{ms}}=0.11$

Reduce the 0.03W time delay from m=4 to the m=5 energy consumption and increased 53ms.

${\mathrm{\&eta;}}_3=\frac{0.03W/0.365W}{53\mathrm{ms}/55\mathrm{ms}}=0.085$

The m value is 3 o'clock, and energy increases maximum, and time delay increases minimum, and time delay and energy-efficient reach maximum balance, so m=3 is an optimum value.

Claims (1)

1. the electricity saving method of an IEEE802.16e park mode is characterized in that: in base station and both sides, terminal a counter is set respectively, when the terminal the audit window of dormancy period receive or send a secondary data then counter values add one; Counting process is necessary for continuous, if continuous a plurality of dormancy period has data arrives, but the count value of counter does not surpass the threshold value m that sets; And the next cycle free of data arrives; Then two counters put 0 simultaneously, restart counting, and this process is called counting and interrupts; When the statistical value of counter surpassed set threshold value m, the terminal got into general mode from park mode; For different minimum sleep window and maximum sleep window, the value of m calculates through setting up the Markov analytical model;

Implementation step is following,

The first step: two counters are provided with threshold value;

Second step: the terminal through and the base station between exchange of signaling get into park mode;

The 3rd step: get into resting state, terminal and base station initiated counters count have the dormancy period number of transfer of data continuously; If counting is interrupted then two counters put 0 simultaneously, restart counting;

The 4th step: whether the detection counter record value surpasses threshold value;

The 5th step: counter does not surpass the threshold value terminal to be continued to keep park mode, repeats for the 4th step;

The 6th step: counter surpasses threshold value, and the terminal is withdrawed from park mode and got into general mode;

Wherein definite step of threshold value is following:

Setting the m value is the threshold value of counter; α _n(1≤n≤max) expression gets into the probability of next dormancy period n+1 from dormancy period n; α _NExpression is from the probability of general mode entering park mode, β _n(m≤n≤max) expression gets into the probability of general mode from dormancy period n; Each dormancy period is made up of an audit window and a sleep window; Audit window length is definite value L, and initial sleep window size is t ₁, the size of the sleep window of n the dormancy period of regulation that calculates according to the relevant sleep window of agreement IEEE802.16E is:

$t_n=\left\{\begin{array}{cc}{2}^{n-1}{t}_1,& 2^{n-1}{t}_1<t_{\max }\\ t_{\max },& 2^{n-1}{t}_1\&GreaterEqual;t_{\max }\end{array}\right.---\left(1\right)$

It is the Poisson process of λ (frame/second) that access rate is obeyed in the transmission of terminal data frame; So, the probability that does not have transfer of data in the time t according to being defined in of Poisson formula is e ^{-λ t}, the corresponding probability that transfer of data is arranged is 1-e ^{-λ t}Dormancy period n (total time of 1≤n≤max) be sleep window duration tn and audit window duration L with; There is the probability of transfer of data to do at dormancy period n so

If setting the counter gate limit value is m; Then β n physical significance is when m≤n≤max-1: dormancy period n; Before; M-1 the dormancy period that begins from dormancy period n-m+1 all has transfer of data, and dormancy period n also has transfer of data, and promptly m dormancy period has transfer of data then to enter into general mode after n dormancy period continuously; M dormancy period has the probability of transfer of data to do continuously Work as n<during m, no matter dormancy period has or not transfer of data, all can not satisfy a continuous m dormancy period gets into general mode by transfer of data requirement, so probability is 0; When n=max, owing to there is not next dormancy period, can only get into general mode from park mode, so β _MaxExpression is by the probability of maximum sleep window entering general mode, and its value equals 1;

${\mathrm{\&beta;}}_n=\left\{\begin{array}{cc}0,& (n<m)\\ \underset{i=n-m+1}{\overset{n}{\mathrm{\&Pi;}}}(1-e^{-\mathrm{\&lambda;}(t_i+L)})& (m\&le;n\&le;\max -1)\\ 1,& (n=\max )\end{array}\right.---\left(2\right)$

If do not satisfy the condition that gets into general mode, will get into dormancy period n+1 from dormancy period n so at dormancy period n; Use α _n(expression of 1≤n≤max) from dormancy period n get into next dormancy period probability; As 1≤n<during m, no matter have or not transfer of data all can get into next dormancy period, so α _nValue be 1; When m≤n≤max-1, this moment, the terminal might get into next dormancy period, also might satisfy the condition that gets into general mode, therefore get into next dormancy period probability equal total probable value 1 and deduct the probability that gets into general mode, i.e. 1-β _nUse α _NThe expression general mode gets into the probability of initial dormancy period 1, get into dormancy period owing to locate the terminal of general mode through exchange of signaling, so its value is 1;

${\mathrm{\&alpha;}}_n=\left\{\begin{array}{cc}1,& (1\&le;n<m)\\ 1-{\mathrm{\&beta;}}_n,& (m\&le;n\&le;\max -1)\end{array}\right.---\left(3\right)$

β _n, α _n, α _NBe the state transition probability between each dormancy period of terminal and the general mode, be in the probability π of each dormancy period when obtaining t → ∞ so _n(1≤n≤max) and the probability π that is in general mode _NComputing formula be:

$\left\{\begin{array}{cc}& \\ {\mathrm{\&pi;}}_{n+1}={\mathrm{\&alpha;}}_n{\mathrm{\&pi;}}_n,(1\&le;n<\max )& \left(a\right)\\ {\mathrm{\&pi;}}_1={\mathrm{\&alpha;}}_N{\mathrm{\&pi;}}_N& \left(b\right)\\ {\mathrm{\&pi;}}_N=\underset{i=m}{\overset{\max }{\mathrm{\&Sigma;}}}{\mathrm{\&beta;}}_i{\mathrm{\&pi;}}_i& \left(c\right)\end{array}\right.---\left(4\right)$

(a) physical significance of formula is as (1≤n<max) time, the probability of dormancy period n entering dormancy period n+1 equals to obtain the probability π of dormancy period n _nMultiply by the probability α that gets into dormancy period n+1 by dormancy period n _n(b) physical significance is that the probability of obtaining dormancy period 1 is the probability π that is in general mode _NGet into park mode probability α with general mode _NProduct; (c) the expression probability of obtaining general mode equals the probability sum that each dormancy period gets into general mode

The probability of each dormancy period entering general mode equals to be in the probability π of each dormancy period _iGet into general mode probability β with this dormancy period _iProduct; With α _n, α _N, β _nThe formula after simplifying of substitution formula (4) does

$\left\{\begin{array}{c}{\mathrm{\&pi;}}_N={\mathrm{\&pi;}}_1=\&CenterDot;\&CenterDot;\&CenterDot;={\mathrm{\&pi;}}_m\\ {\mathrm{\&pi;}}_{n+1}={\mathrm{\&pi;}}_n{\mathrm{\&alpha;}}_n,(m\&le;n<\max )\\ {\mathrm{\&pi;}}_N=\underset{i=m}{\overset{\max }{\mathrm{\&Sigma;}}}{\mathrm{\&beta;}}_i{\mathrm{\&pi;}}_i\end{array}\right.---\left(5\right)$

In conjunction with formula

${\mathrm{\&pi;}}_N=\underset{i=1}{\overset{\max }{\mathrm{\&Sigma;}}}{\mathrm{\&pi;}}_i=1---\left(6\right)$

Promptly try to achieve the probability π of dormancy period _n(1≤n≤max) and the probability π that is in general mode _N

The energy consumption power at sleep window terminal is E _S, audit window energy consumption power is E _RxThe energy consumption of a dormancy period is divided into two parts, the energy consumption (L*E of the energy consumption of audit window and sleep window _Rx+ tk*E _S); If obtain dormancy week i, the summation of i dormancy period energy consumption promptly before the total energy consumption in terminal should be So the average energy consumption value should be the total energy consumption product of the probability of obtaining each dormancy period and this dormancy period with:

$E=\underset{i=1}{\overset{\max }{\mathrm{\&Sigma;}}}\left(\underset{k=1}{\overset{i}{\mathrm{\&Sigma;}}}(L*E_{\mathrm{rx}}+t_k*E_S)\right)*{\mathrm{\&pi;}}_i---\left(7\right)$

Consider the randomness of Poisson distribution, the due in of tentation data frame in the same dormant stage obeyed evenly and distributed, and obtains average delay and is:

$E\left(t\right)=\underset{i=1}{\overset{\max }{\mathrm{\&Sigma;}}}\left(\frac{L+t_i}{2}\right)*{\mathrm{\&pi;}}_i---\left(8\right)$

Show that according to lot of experiment results along with the increase of m value, the average energy consumption value is more little, but because the restriction of delaying time for data processing in the terminal, m value long time delay more is long more; So can not be with the unconfined maximum of m value; Experimental result shows that energy-efficient is linear growth when m increased gradually before max/3; Behind max/3, energy-efficient is little for max/3 increases than the m value, and time delay is and still is linear growth; Therefore, the value of m value should be (, max/3-2, the integer value in max/3+2) interval, the average energy consumption and the average delay that calculate according to formula (7), (8); And appropriate m value must be able to make

$\mathrm{\&eta;}=\frac{(E_{m_{i-1}}-E_{m_i})/E_{m_{i-1}}}{(E_{m_i}\left(t\right)-E_{m_{i-1}}\left(t\right))/E_{m_{i-1}}\left(t\right)}---\left(9\right)$

Value reach maximum, the physical significance of formula (9) is: energy-efficient reaches maximum, and time delay increases minimum; The m value of this moment is required m value.

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