WO2015000159A1

WO2015000159A1 - Channel access method and communication equipment

Info

Publication number: WO2015000159A1
Application number: PCT/CN2013/078804
Authority: WO
Inventors: 刘永俊; 杨晖
Original assignee: 华为技术有限公司
Priority date: 2013-07-04
Filing date: 2013-07-04
Publication date: 2015-01-08

Abstract

Disclosed is a channel access method, the method comprising: determining according to the conditions of a channel that random back-off is needed currently; in the process of random back-off execution, performing a first dormancy with a duration of Tbreak1 when continuous channel listening time reaches maximal continuous listing time Tmax, and stopping channel listening during the first dormancy; continuing executing the random back-off after a wakeup from the first dormancy; and accessing the channel upon completion of the random back-off. Further disclosed is communication equipment. The adoption of the present invention enables the timely recovery of power storage in the communication equipment, avoiding such a situation where the equipment fails to work normally on account of over-discharge of the power source or depletion of the power stored.

Description

Channel access method and communication device

The present invention relates to the field of communications, and in particular, to a channel access method and a communication device. Background technique

In recent years, WiFi/IEEE 802.11 has been used in low-speed scenes including the Internet of Things. At this time, communication equipment has high requirements for low power consumption, and there are a large number of devices, which are usually powered by batteries or self-collecting energy. WiFi/IEEE 802.11 adopts random channel access mode based on CSMA/CA for persistent monitoring, that is, the channel is monitored before transmitting data, and if the channel is idle, data is transmitted, otherwise a random backoff process is initiated, and in the process of random backoff Continuous monitoring of the channel begins to count down the random backoff counter only if the channel is idle for a certain length of time. When the counter is reduced to zero, the data is sent immediately. For battery-powered or self-collecting energy sources, there are major problems with existing access-based access methods. The main reason is to perform continuous monitoring when random backing, and the power consumption during monitoring is not negligible, which will make the power supply in a state of continuous discharge. If the monitoring time is long, the actual life of the battery will be significantly reduced. Or if the power is supplied from the self-collecting energy source, the power consumption exceeds the maximum power that can be supplied in a short period of time, so that the device cannot communicate normally. Summary of the invention

The technical problem to be solved by the embodiments of the present invention is to provide a channel access method and a communication device, which can enable the communication device to maintain normal operation under the condition of battery power supply or self-collected energy supply.

In order to solve the above technical problem, a first aspect of the embodiments of the present invention provides a channel access method, where the method includes:

Confirm that the current backoff is required according to the channel condition;

During the execution of the random backoff process, when the continuous channel listening time reaches the continuous listening maximum time T _max , the first sleep of the duration T _brcakl is performed, and the channel monitoring is stopped _during the first sleep; - - continuing to perform the random backoff after the first sleep wakes up;

The channel is accessed after the random backoff is completed.

With reference to the first aspect, in a first possible implementation manner, after the confirming that a random backoff is currently required according to a channel condition, the method includes:

Get the current backoff time T _baek before starting random backoff. _Ff ;

If T _back . _ff is greater than T _max, the duration of the second sleep _T brcak2 stopped listening channel when the second sleep;

After the second sleep wakes up, random backoff is started.

With reference to the first possible implementation manner of the first aspect, in a second possible implementation manner, the performing the random backoff after the second sleep wakeup includes:

After the second sleep wakes up, the backoff time is recalculated, and the random backoff is started according to the recalculated backoff time.

In conjunction with the second possible implementation of the first aspect, in a third possible implementation, the recalculating the backoff time includes:

The size of the competition window for determining the back-off time is reduced, and the back-off time is recalculated by the reduced contention window.

In conjunction with the second possible implementation of the first aspect, in a fourth possible implementation, the recalculating the backoff time includes:

A second backoff time before the set sleep is T _baek. _Ff , the recalculation backoff time is rand(0, a*T _backoff ), where 0<a<2.

With reference to the first aspect or the second to fourth possible implementation manners of the first aspect, in the fifth possible implementation, the recalculating the backoff time further includes:

Confirm that the current accumulated sleep time reaches the preset threshold.

With the first aspect or the second to fifth possible implementation manners of the first aspect, in a sixth possible implementation manner, the performing the random backoff after the first sleep wakeup includes:

After the first sleep wakeup, the virtual backoff time T _v =p*T _brcaM is subtracted from the remaining backoff time, where p is the pre-estimated network busy probability.

In conjunction with the first aspect or the second to sixth possible implementations of the first aspect, in a seventh possible implementation, the T _breakl =T _rcc . _Ver , where T _remvef is based on the communication device itself - - The battery recovery time determined by the pool characteristic parameter or the energy harvesting characteristic parameter.

With reference to the first aspect, or the second to the sixth possible implementation manner of the first aspect, in the eighth possible implementation manner, the determining, before confirming that the random backoff is currently required according to the channel condition, further includes:

Obtain the T _{breakl delivered by the} access point device.

With reference to the first aspect or the second to sixth possible implementation manners of the first aspect, in the ninth possible implementation manner, the determining, before confirming that the random backoff is currently required according to the channel condition, further includes:

Obtain a reference recovery time Tw _delivered by the access point device;

According to the battery characteristic parameter or the energy collection characteristic parameter of the communication device itself, the power recovery time ^ ^ ^ recover;

Determine that T _break is the smaller of 1^ and T _re∞ .

With reference to the ninth possible implementation of the first aspect, in a tenth possible implementation, the method further includes:

Modify the maximum _contention window parameter of the communication device according to 1^ and T _re∞w .

With reference to the tenth possible implementation manner of the first aspect, in the eleventh possible implementation manner, the modifying the maximum _contention window parameter of the communication device according to the 1^ and the T _re∞ includes:

It is assumed that the maximum competition window before the modification of the communication device is cw. , the revised maximum competition window is

* -! , where k is the largest integer not greater than log ₂ (T _w /T _rec . _ver ).

Correspondingly, the second aspect of the embodiments of the present invention further provides a communication device, where the communication device includes:

a random backoff confirmation module, configured to confirm that a random backoff is currently required according to a channel condition; and a backoff module, configured to perform a random backoff;

a first hibernation module, configured to perform a first dormancy with a duration of T _{breakl and} a channel dormant for the first dormancy when the persistent channel listening time reaches a continuous listening maximum time T _max during the random backoff process performed by the backoff module, After a sleep wakes up, the backoff module is triggered to continue to perform random backoff;

An access module, configured to access a channel after performing random backoff completion.

With reference to the second aspect, in a first possible implementation manner, the communications device further includes: a second dormant module, configured to acquire a current backoff before the backoff module starts performing random backoff - - Time T _back . _Ff , if T _back . _{If ff is} greater than T _max , a second sleep with a duration of T _brcak 2 is performed, and channel snooping is stopped _during the second sleep, and the second _loop wakes up to trigger the backoff module to start performing random backoff.

With reference to the first possible implementation of the second aspect, in a second possible implementation, the second dormant module includes:

a backoff time calculation unit, configured to recalculate the backoff time;

The backoff triggering unit is configured to trigger the backoff module to perform random backoff according to the recalculated backoff time.

In conjunction with the second possible implementation of the second aspect, in a third possible implementation, the backoff time calculation unit is specifically configured to:

With reference to the second possible implementation of the second aspect, in a fourth possible implementation, the backoff time calculation unit is specifically configured to:

Let the backtime before the second sleep be T _baek . _ff, corresponding to the backoff time is recalculated _{rand (0, a * T back} . ff), wherein 0 <a <2.

With reference to the second aspect or the second to fourth possible implementation manners of the second aspect, in the fifth possible implementation, the second hibernation module further includes:

The sleep accumulation threshold unit is configured to trigger the backoff time calculation unit to recalculate the backoff time when the current accumulated sleep time reaches the preset threshold.

With reference to the second aspect or the second to fifth possible implementation manners of the second aspect, in the sixth possible implementation, the first dormant module includes:

The virtual backoff calculation unit is configured to subtract the virtual backoff time T _v =p* T _breakl from the remaining backoff time after the first sleep wakeup, where p is a pre-estimated network busy probability.

In conjunction with the second aspect or the second to sixth possible implementations of the second aspect, in a seventh possible implementation, the T _breakl =T _rec . _ver, wherein _T rc∞VCT own battery recovery time characteristic parameter or parameters determined in accordance with characteristics of the energy harvesting power communication device.

With reference to the second aspect, the second to the sixth possible implementation manner of the second aspect, in the eighth possible implementation, the first dormant module includes:

The first sleep time acquisition unit is configured to acquire T _{breakl delivered by the} access point device. With reference to the second aspect, the second to the sixth possible implementation manner of the second aspect, in the ninth possible implementation manner, the first dormant module includes:

a second sleep time acquisition unit, configured to acquire a reference recovery time Tw _delivered by the access point device, and determine a power recovery time according to the battery characteristic parameter or the energy collection characteristic parameter of the communication device itself

T _recover , determines that T _break is the smaller of T _w and T recover.

With reference to the ninth possible implementation of the second aspect, in the tenth possible implementation, the first dormant module further includes:

The competition window modification unit is configured to modify the maximum _contention window parameter of the communication device according to 1^ and T _re∞w . With reference to the tenth possible implementation of the second aspect, in the eleventh possible implementation, the contention window modification module is specifically configured to:

*! -, wherein k is not greater than _{_{_{log 2 (T w / T rec}}} ver.) The largest integer.

Correspondingly, a third aspect of the embodiments of the present invention further provides a communications device, including: a receiving module, a sending module, a memory, and a processor, wherein the memory stores a set of program codes, and the processor is configured to call the storage in the memory. Program code, used to do the following:

Confirming that random backoff is currently required according to the channel condition monitored by the receiving module;

During the execution of the random backoff process, when the continuous channel listening time reaches the continuous listening maximum time T _max , the first sleep with the duration T _break1 is performed, and the receiving module stops the channel monitoring during the first sleep; the first sleep wakes up and continues to execute the random Retreat

After the random backoff is completed, the channel is accessed through the sending module.

With reference to the third aspect, in a first possible implementation manner, the processor performs the following operations after performing the random backoff according to the channel condition of the snoop receiving module:

Get the current backoff time T _baek before starting random backoff. _Ff ;

If Tbackcrff is greater than ^T _maX , performing a second sleep with a duration of T _break 2 , and the receiving module stops channel monitoring during the second sleep;

The random backoff is started after the second sleep wakes up.

With reference to the first possible implementation manner of the third aspect, in a second possible implementation manner, the processor performs wake-up after a sleep T _break2 , starts channel monitoring, and starts performing a random backoff operation, where - - Re-calculate the back-off time after the second sleep wake-up, and start random back-off based on the recalculated back-off time.

With reference to the second possible implementation manner of the third aspect, in a third possible implementation manner, the processor performs an operation of recalculating a backoff time, including:

In conjunction with the second possible implementation of the third aspect, in a fourth possible implementation, the performing, by the processor, re-calculating the backoff time includes:

Let the backtime before the second sleep be T _baek . _Ff , the retraction time corresponding to the recalculation is rand(0, a*T _back _ff ), where 0<a<2.

With reference to the third aspect or the second to fourth possible implementation manners of the third aspect, in a fifth possible implementation manner, the processor performs the following operations before performing the operation of recalculating the backoff time:

Confirm that the current accumulated sleep time reaches the preset threshold.

With reference to the third aspect, or the second to fifth possible implementation manners of the third aspect, in a sixth possible implementation, the performing, by the processor, performing the operation of the random backoff after performing the first sleep wakeup includes:

After the first sleep wakeup, the virtual backoff time T _v =p*T _breaM is subtracted from the remaining backoff time, where p is the pre-estimated network busy probability.

Binding third to sixth aspect or the second possible implementation of the third aspect, in the seventh possible implementation manner, the T _breakl = T _rec. _Ver , where T _re∞ve r is the power recovery time determined according to the battery characteristic parameter or the energy collection characteristic parameter of the communication device itself.

With reference to the third aspect, or the second to sixth possible implementation manners of the third aspect, in an eighth possible implementation manner, the performing, by the processor, performing the operation that performs the random backoff according to the channel condition is further performed. The following operations:

Obtaining, by the receiving module, the T _{breaM delivered} by the access point device.

With reference to the third aspect, or the second to the sixth possible implementation manners of the third aspect, in a ninth possible implementation manner, the performing, by the processor, performing the operation of performing the random backoff according to the channel condition is further performed The following operations: - - delivered by the module obtains the access point device with reference to the recovery time T _w by said receiving;

Determine that T _break is the smaller of 1^ and T _re∞ .

In conjunction with the ninth possible implementation of the third aspect, in a tenth possible implementation, the processor is further configured to perform the following operations:

With reference to the tenth possible implementation manner of the third aspect, in an eleventh possible implementation manner, the processor performs an operation of modifying a maximum _contention window parameter of the communication device according to 1^ and T _re∞ , including: The maximum competition window before the communication device is modified is cw. , the revised maximum competition window is

In the embodiment of the present invention, by introducing a sleep process for a preset time in the channel access process, the storage power of the communication device can be restored in time, and the power supply is prevented from being over-discharged or the stored power is exhausted, so that the device cannot work normally. DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description It is merely some embodiments of the present invention, and those skilled in the art can obtain other drawings according to these drawings without any creative work.

1 is a schematic flowchart of a channel access method according to an embodiment of the present invention;

2 is a schematic flowchart of a channel access method according to another embodiment of the present invention;

3 is a schematic flowchart of a channel access method according to another embodiment of the present invention;

4 is a schematic structural diagram of a communication device according to an embodiment of the present invention;

5 is a schematic structural diagram of a first sleep module of a communication device according to an embodiment of the present invention;

6 is a schematic structural diagram of a second sleep module of a communication device according to an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of a communication device in another embodiment of the present invention. detailed description The technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, but not all embodiments. . All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

1 is a schematic flowchart of a channel access method according to an embodiment of the present invention. As shown in the figure, the channel access method in this embodiment may include:

5101. It is detected that channel access is required. Specifically, the communication device may need to send data due to application triggering, etc., to determine that channel access is currently required.

5102. Confirm that the random backoff is currently required according to the channel condition. Specifically, before the access channel sends data, the channel can be determined to be busy. If the current channel condition meets the preset access condition, the channel access can be directly initiated. Otherwise, random backoff is required.

5103, Perform random backoff. Specifically, in the embodiment of the present invention, the current random backoff time T _back can be determined by selecting a random time value between 0 and the competition window. _ff, the backoff process performed continuously monitor the channel, only when the channel is idle for more than a certain time before the backoff counter is counting down. The competition window may set an initial maximum value and a minimum value, and dynamically adjust the current contention window size of the communication device according to the data transmission failure or success. Other existing methods of calculating random backoff time may also be employed in other alternative embodiments.

S104: Determine whether the random backoff is completed, if yes, execute S107, otherwise execute S105.

5105, continued to determine whether the channel listening time arrives continuously monitors the maximum time T _max, and if so, perform S106, otherwise continue to perform random backoff. In this embodiment, when the random backoff is performed, the channel is continuously monitored. When the continuous channel listening time reaches the maximum listening time, the communication device may consume more power than the energy storage module of the communication device (for example, the storage capacitor in parallel for the power supply circuit, The equivalent capacity of the battery, etc., can store the power, which may cause the power supply to be over-discharged. If it is powered by the self-collecting energy source, it may also exhaust the previously stored power, making the device unable to work normally. There are n states when the communication device continues to work, and the duration ti of each state, wherein the duration of each state except the listening time (including the switching time from the active state to the sleep state, the time required to send the data packet, etc.) It is known that the current consumption is Ii, where i=l, 2, ··. , !!, then the maximum listening time T _{max in} the battery-powered scenario can be calculated according to the following formula:

C

Ti)]/(V _max - V _min ) , where is the equivalent of the battery of the communication device - - resistance, v _min is the minimum supply voltage to support the normal operation of the communication device, v _max is the voltage on the capacitor at the beginning of the battery life, C is the equivalent capacitance of the communication device battery, and ∑ ti is obtained by the above formula The maximum listening time T _max in a battery-powered scenario can be obtained by going to all known tis. In the self-acquisition power supply environment, T _max is not higher than the maximum stored energy of the communication device according to the total power consumption (3⁄4^ To determine, that is, Q _max ∑Ii*ti, by subtracting all known ti from ∑ ti obtained by the above formula, the maximum listening time T _{max in the} self-collecting power supply environment can be obtained.

5106: Perform a first sleep with a duration of T _breakl , and stop channel monitoring during the first sleep. Performing the first hibernation can restore the storage capacity of the communication device, avoiding excessive discharge of the power supply or exhausting the stored power so that the device does not work properly. The random backoff is continued after the first sleep wakes up. In the embodiment of the present invention, T _breakl can be determined in the following three ways:

Manner 1: T _breakl can take the value of T _re∞VCT , and T _re∞VCT is the power recovery time determined according to the battery characteristic parameter or the energy collection characteristic parameter of the communication device itself. Taking the battery-powered scene as an example, it can be calculated by the following formula: T recover*

T _rec0 ver=RiC*ln[(V _p -V _min )/(V _p -V _max )], where Ri is the equivalent resistance of the battery of the communication device,

C is the equivalent capacitance value of the battery, V _min is the lowest supply voltage, V _max is the voltage on the capacitor at the beginning of the battery life change, and V _p is the battery voltage at no load.

In the case of self-collecting energy supply, 1^ may be changed, and the device needs to estimate the T _re∞w according to the change of the environment or the historical situation of the previous electricity generation.

In the second mode, the T _{breakl delivered by the} access point device is obtained in advance. That is, the power recovery time specified by the network can be sent by the access point device to the communication device when the communication device enters the network.

Three ways, previously delivered by the access point acquires the reference time T _W recovery, and energy acquisition characteristic parameter or parameters determined according to the communication apparatus itself battery charge characteristic recovery time _T re∞ve r, as determined _BREAK T _W T and T _Rec . The smaller value in _w . Further in an alternative embodiment, it is also possible to base T _w and T _rec . _Ver modifies the maximum competition window parameter of the communication device. For example, if the maximum competition window before the modification of the communication device is CW ₀ , the modified maximum competition window is CW CW0+1V2 L1 , where k is the largest integer not greater than log ₂ (T _w /T _rec . _ver ).

5107, access channel. After the random backoff is completed, the communication device can initiate an access channel. FIG. 2 is a schematic flowchart of a channel access method according to another embodiment of the present invention. The channel access method in this embodiment may include: - -

5201, detecting that channel access is required. Specifically, the communication device may need to send data due to application triggering, etc., to determine that channel access is currently required.

5202. Confirm that the current backoff is required according to the channel condition. Specifically, before the access channel sends data, the channel can be determined to be busy. If the current channel condition meets the preset access condition, the channel access can be directly initiated. Otherwise, random backoff is required.

5203. Determine whether the backoff time is greater than a continuous listening maximum time _Tmax . Specifically, the communication device may acquire the current backoff time T _back before starting to perform random backoff. _Ff , if T _back . _{If ff is} greater than T _max , that is, the random backoff cannot be completed within the maximum listening duration, then S204 is performed, otherwise S205 is performed.

5204: Perform a second sleep with a duration of T _break2 , and stop channel monitoring during the second sleep. Specifically, the duration T _{break2 of the} second sleep may be the same as the duration T _{brcak1 of the} first sleep. In an alternative embodiment, the communication device only performs the initial channel monitoring operation, and the monitoring time is usually short (such as several hundred us), and does not consume too much power, so T _brcak2 can also be based on The current power consumption takes a shorter time value.

5205. After the second sleep wakes up, random backoff is performed.

S206: Determine whether the random backoff is completed, if yes, execute S211, otherwise execute S207.

S207: Determine whether the persistent channel listening time reaches the continuous listening maximum time _Tmax , and if yes, execute S208, otherwise continue to perform random backoff.

5208, performing a first sleep with a duration of T _breakl , and stopping channel monitoring during the first sleep. Performing the first hibernation can restore the storage capacity of the communication device, avoiding excessive discharge of the power supply or exhausting the stored power so that the device does not work properly. The calculation method of the T _breakl is described in detail in the foregoing embodiment, and is not described in detail in this embodiment.

5209. After the first sleep wakeup, the virtual backoff time T _v =p* T _breakl is subtracted from the remaining backoff time, where p is a pre-estimated network busy probability. In the specific implementation, the network busy probability p is an estimate of the busyness of the network service, and can be estimated according to the average network traffic, for example, may be equal to the average network traffic divided by the total throughput, or may be estimated in advance by the access point. And sent to the communication device of the access channel. It should be noted that S208 is an optional step in this embodiment, and the total access delay caused by the first sleep can be reduced after execution.

5210, determining whether the random backoff is completed, if yes, executing S211, otherwise continuing to execute - - Machine back. Specifically, if the virtual backoff time T _v is subtracted from the remaining backoff time by S209, and the remaining backoff time is not greater than 0, S211 may be performed; otherwise, the remaining backoff process is continued.

S211, access channel. That is, when the random backoff is completed, the communication device can initiate an access channel. FIG. 3 is a schematic flowchart of a channel access method according to another embodiment of the present invention. As shown in the figure, the channel access method in this embodiment may include:

5301. It is detected that channel access is required. Specifically, the communication device may need to send data due to application triggering, etc., to determine that channel access is currently required.

5302. Confirm that the current backoff is required according to the channel condition. Specifically, before the access channel sends data, the channel can be determined to be busy. If the current channel condition meets the preset access condition, the channel access can be directly initiated. Otherwise, random backoff is required.

5303, to determine the wait time is greater than the maximum time continuously monitoring the T _max. Specifically, the communication device may acquire the current backoff time T _back before starting to perform random backoff. _Ff , if T _back . _ff is greater than T _max, i.e., not capable of continuously monitoring the maximum random backoff time to complete, S304, is executed, otherwise, execute S308.

5304: Perform a second sleep with a duration of T _break2 , and stop channel monitoring during the second sleep. The details are the same as those in S204 in the previous embodiment, and are not described in this embodiment.

5305. Determine whether the currently accumulated sleep time reaches a preset threshold. Specifically, the sleep time may be accumulated from the previous calculation of the backoff time, for example, after each update of the competition window. After the second sleep wakes up, it is judged whether the currently accumulated sleep time reaches the preset time threshold. If yes, S306 is recalculated to calculate the backoff time, otherwise, S308 is performed. It should be noted that S305 is an optional step in this embodiment, that is, in an alternative embodiment, S306 may be re-calculated after the second sleep wake-up.

S306 Recalculates the backoff time. Specifically, after the communication device enters sleep, a relatively large delay may be added to the service. To shorten the delay, the backoff time may be recalculated after the second sleep wake-up to shorten the average access delay. In the specific implementation, the backoff time can be recalculated in the following two ways:

1) is to reduce the size of the competition window for determining the back-off time, and recalculate the back-off time by the reduced competition window. The size of the competition window can be reduced after each second sleep wake up, until it is reduced - - The minimum value of the battle window is shortened, so that the calculated average backoff time is shortened to achieve an average access delay.

2) The recalculated backoff time is rand(0, a* T _back _ff ), where 0<a<2, T _baek . _Ff is the backoff time before the second sleep, that is, 0 to a* T _baek . A random number between _ff , the preferred constant a can take 0 < a < l.

5307. Determine whether the backoff time is greater than the continuous listening maximum time _Tmax . It is judged whether the recalculated backoff time is still greater than T _max , and if so, it indicates that it is still impossible to complete the backoff within the maximum listening duration, and S304 can be re-executed, otherwise the current T _baek . _ff less than the T _max indicates a random backoff may be completed within a maximum time duration listening, and may perform the S308.

5308. Perform the random backoff.

S309: Determine whether the random backoff is completed, if yes, execute S312, otherwise execute S310.

5310: Determine whether the continuous channel listening time reaches the continuous listening maximum time T _max , and if yes, execute S311, otherwise continue to perform random backoff.

5311: Perform a first sleep with a duration of T _breakl , and stop channel monitoring during the first sleep.

5312, access channel. After the random backoff is completed, the communication device can initiate an access channel. In the specific implementation, the S308 and the subsequent S309-S312 are the same as the S103-S107 in the previous embodiment, and may be referred to in the foregoing embodiment, and are not described in this embodiment.

FIG. 4 is a schematic structural diagram of a communication device according to an embodiment of the present invention. As shown in the figure, the communication device in the embodiment of the present invention may include at least:

The random backoff confirmation module 410 is configured to confirm that a random backoff is currently required according to the channel condition. In a specific implementation, the communication device may need to send data due to application triggering, etc., thereby determining that channel access is currently required, and the channel busy state may be determined by monitoring the channel before the access channel transmits data, if the current channel condition satisfies the preset connection. The entry condition can directly initiate channel access, otherwise random backoff is required.

The backoff module 420 is configured to perform random backoff. Specifically, in the embodiment of the present invention, the backoff module 420 may determine the current random backoff time T _backoff by selecting a random time value between 0 and the competition window, and continuously monitor the channel during the backoff process, only when the channel is idle for more than a certain period. The time backoff module 420 performs the backoff counter down counting. The competition window may set an initial maximum value and a minimum value, and dynamically adjust the current contention window size of the communication device according to the data transmission failure or success. In its - - Other existing methods of calculating random backoff time may also be employed in alternative embodiments.

First sleep module 430 for the process module 420 performs a random backoff backoff when a channel duration time duration reaches the maximum duration listening time T _max, the duration of the first sleep T _breakl, the first channel-sounding stop Sleep After the first sleep wakes up, the trigger backoff module 420 continues to perform random backoff. Specifically, in this embodiment, the backoff module 420 performs the continuous listening channel during the random backoff process, and when the continuous channel listening time reaches the continuous listening maximum time T _max , it indicates that the communication device consumes more power than the communication device energy storage module (for example, power supply) The amount of power that can be stored by the parallel storage capacitors, the equivalent capacitance of the battery, etc., may cause the power supply to be over-discharged. If it is powered by the self-collecting energy source, it may be exhausted before the power stored so that the device does not work properly. There are n states when the communication device continues to work, and the duration of each state is ti, wherein the duration of each state except the listening time (including the switching time from the active state to the sleep state, and the time required to send the data packet) Etc.) are known, the current consumption is Ii, where i = l, 2,...,! 1, then the listening time at the maximum battery power the scene T _max can be calculated according to the formula:

C

Ti)]/(V _max - V _min ) , where is the equivalent resistance of the battery of the communication device, V _min is the lowest supply voltage supporting the normal operation of the communication device, and V _max is the voltage on the capacitance at the beginning of the discharge of the battery life. C is the equivalent capacitance of the cell communication device, by the formula obtained by subtracting all known Σti ti, to obtain the scene under battery power monitor a maximum time T _max; in an electric power collection from ambient T _max According to the total power consumption is not higher than the maximum stored energy of the communication device (3⁄4^ to determine, that is, Q _max ∑Ii*ti, the ∑ti obtained by the above formula minus all known ti, then the self-collecting power supply can be obtained. monitor the maximum time T _max under the circumstances.

Therefore, the first hibernation module 430 triggers the first hibernation to enable the storage device to recover the power, avoiding the power supply being over-discharged or exhausting the stored power, so that the device cannot work normally, and the first dormant wake-up triggers the retreat module 420 to continue performing the Random backoff. In the embodiment of the present invention, T _breakl can be determined in the following three ways:

Method 1: T _breakl possible value of T _rce. , T _rce . For the battery recovery time determined according to the battery characteristic parameter or the energy collection characteristic parameter of the communication device itself, taking the battery-powered scene as an example, the T recover* can be calculated by the following formula:

C is the equivalent capacitance value of the battery, V _min is the lowest supply voltage, and V _max is the end of the battery life. - - The voltage at the beginning of the capacitor, V _p is the battery voltage at no load.

In the case of self-collecting energy supply, T _re∞ver may change, and the device needs to estimate the T _{re∞ ver} according to the change of the environment or the historical situation of the previous electricity generation.

Three ways, previously delivered by the access point acquires the reference time T _W recovery, and energy acquisition characteristic parameter or parameters determined according to the communication apparatus itself battery charge characteristic recovery time _T re∞ve r, as determined _BREAK T _W T and T _Rec . _ver the smaller value. Further in an alternative embodiment, it is also possible to base T _w and T _rec . _Ver modifies the maximum competition window parameter of the communication device. Such as a maximum window after the competition before the competition window communication device to modify the maximum CW _0, then modify the

, where k is the largest integer not greater than io _g2 (T _w /T _rec . _ver ).

As shown in FIG. 5, the first hibernation module in the embodiment of the present invention may further include: a virtual backoff calculation unit 431, a first sleep time acquisition unit 432, a second sleep time acquisition unit 433, and a competition window modification unit 434. among them:

The virtual backoff calculation unit 431 is configured to subtract the virtual backoff time T _v =p* T _breakl from the remaining backoff time after the first sleep wakeup, where p is a pre-estimated network busy probability. In a specific implementation, the network busy probability p is an estimate of the busyness of the network service, and the virtual backoff calculation unit 431 can estimate the average network traffic, for example, can be equal to the average network traffic divided by the total throughput, and the virtual backoff computing unit The 431 may also obtain the estimated network busy probability p that is estimated and obtained from the access point device in advance. It should be noted that the virtual backoff calculation unit 431 is an optional unit in the embodiment of the present invention, which can reduce the total access delay caused by the first sleep.

The first sleep time acquisition unit 432 is configured to acquire T _{breakl delivered by the} access point device. That is, the first sleep time T _breaM is obtained by the second method described above.

Second sleep time acquisition unit 433 for acquiring the access point device made with reference to the recovery time T _w, or energy parameter acquisition characteristic parameter according to the communication apparatus itself is determined battery charge characteristic recovery time _T re∞VCT, determining T _break For T _w and T _rec . The smaller value in _ver . That is, the first sleep time T _breakl is obtained by the third method described above.

Competitive window modification unit 434, parameters for the maximum competitive window T _w and _T re∞ver modifying communication device. The unit is an optional unit. Specifically, the competition window modification unit 434 is based on T _w and T _rec . _Ver repair - - Change the maximum competition window parameter of the communication device. For example, if the maximum contention window before the modification of the communication device is CW ₀ , the maximum contention window modified by the competition window modification unit 434 is

, where k is the largest integer not greater than log ₂ (T _w /T _re∞ver ).

The access module 440 is configured to access the channel after performing random backoff.

Optionally, the communications device in the embodiment of the present invention may further include:

The second hibernation module 450 is configured to acquire the current backoff time T _back before the backoff module 420 starts performing random backoff. _Ff , if T _baek . _{If ff is} greater than T _max , a second sleep with a duration of T _break 2 is performed, and channel snooping is stopped _during the second sleep, and the second sleep wake-up triggers the backoff module to start performing random backoff. Specifically, if the current backoff time is T _back . _{If ff is} greater than T _max , that is, the random backoff cannot be completed in the continuous listening maximum time, the second sleep is performed for a duration of T _break 2 , and the channel monitoring is stopped _during the second sleep. The duration of the second sleep, T _{break2 ,} may be the same as the duration of the first sleep, T _breakl . In an alternative embodiment, since the communication device only performs the initial channel monitoring operation, the time of the monitoring is usually short (such as several hundred us), and does not consume too much power, so T _break2 also A shorter time value can be taken based on the current power consumption. Optionally, the second hibernation module 450 in the embodiment of the present invention may include at least a backoff time calculation unit 451 and a backoff trigger unit 452, where:

The backoff time calculation unit 451 is for recalculating the backoff time. Specifically, after the communication device enters the sleep state, a relatively large delay may be added to the service. To shorten the delay, the backoff time calculation unit 451 may recalculate the backoff time after the second sleep wakeup to shorten the average access delay. . In a specific implementation, the backoff time calculation unit 451 can recalculate the backoff time in the following two ways:

1) is to reduce the size of the competition window for determining the back-off time, and recalculate the back-off time by the reduced contention window. Each time the second sleep wakes up, the size of the competition window can be reduced until the minimum value of the competition window is reduced, so that the calculated average backoff time is shortened, so as to shorten the average access delay.

The backoff triggering unit 452 is configured to trigger the backoff module 420 to perform random backoff according to the recalculated backoff time. - - The optional second hibernation module 450 may further include:

The sleep accumulation threshold unit 453 is configured to trigger the backoff time calculation unit to recalculate the backoff time when the current accumulated sleep time reaches the preset threshold. In the specific implementation, the sleep accumulation threshold unit 453 may calculate the sleep time from the previous calculation of the backoff time, and determine whether the currently accumulated sleep time reaches the preset time threshold after the second sleep wakeup, and if so, trigger the backoff time calculation. Unit 451 recalculates the backoff time.

FIG. 7 is a schematic structural diagram of a communication device in another embodiment of the present invention. As shown in FIG. 7, FIG. 7 shows a specific embodiment of a communication device. In this embodiment, the communication device 70 can include a transmitting module 702, a receiving module 703, a processor 704, a memory 705, and an antenna 701. Processor 704 is responsible for the logical operation of communication device 70. Memory 705 can include read only memory and random access memory and provides instructions and data to processor 704. A portion of memory 705 may also include non-volatile random access memory (NVRAM). In a specific application, the communication device 70 may be embedded or may itself be a wireless communication device such as an electronic tag, a mobile phone, or may include a carrier that houses the transmitting module 702 and the receiving module 703 to allow the communication device 70 and other communication devices. Such as data transmission and reception between access point devices. Transmitting module 702 and receiving module 703 can be coupled into antenna 701. The various components of communication device 70 are coupled together by a bus system 706, which in addition to the data bus includes a power bus, a control bus, and a status signal bus. However, for clarity of description, various buses are labeled as bus system 706 in the figure.

The method disclosed in the foregoing embodiments of the present invention may be applied to the processor 704, or implemented by the processor 704, and may be used to perform at least the following operations:

Confirming that a random backoff is currently required according to the channel condition monitored by the receiving module 703;

During the execution of the random backoff process, when the continuous channel listening time reaches the continuous listening maximum time T _max , the first sleep of the duration T _break1 is performed, and the first sleep receiving module 703 stops the channel monitoring;

After the first sleep wakes up, the random backoff is continued;

The channel is accessed by the transmitting module 702 after the random backoff is completed.

The communication device described above with reference to FIG. 4 to FIG. 6 may be specifically implemented by the communication device 70 shown in FIG. 7 , and the random backoff confirmation module 410 , the backoff module 420 , and the first dormant module in the communication device. 430. The access module 440 and the second hibernation module 450 are both - is understood to be a logical functional module of the processor 704 in the communication device 70 of FIG. Processor 704 may be an integrated circuit chip with the ability to execute instructions and data, as well as the processing capabilities of the signals. In the process of implementing the channel access method in the embodiment of the present invention, the steps of the method introduced in FIG. 1 to FIG. 3 may be completed by an integrated logic circuit of hardware in the processor 704 or an instruction in a form of software. The above processor may be a general purpose processor (CPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), an off-the-shelf programmable gate array (FPGA) or other programmable logic device, a discrete gate or a transistor logic device, Discrete hardware components. The methods, steps, and logical block diagrams disclosed in the embodiments of the present invention may be implemented or executed. The general purpose processor may be a microprocessor or the processor or any conventional processor or the like. The processor 704 can be at least one microprocessor. The steps of the method disclosed in the embodiments of the present invention may be directly implemented as a hardware processor, or may be performed by a combination of hardware and software modules in the processor. The software modules can be located in a conventional storage medium such as random access memory, flash memory, read only memory, programmable read only memory or electrically erasable programmable memory, registers, and the like. The storage medium is located in the memory 705. The processor 704 reads the information in the memory 705, and performs some or all of the steps including the power channel access method described in the foregoing embodiment of the method shown in FIG. 1 to FIG.

In the embodiment of the present invention, by introducing a sleep process for a preset time in the channel access process, the storage capacity of the communication device can be restored, and the power supply is prevented from being over-discharged or the stored power is exhausted, so that the device cannot work normally.

A person skilled in the art can understand that all or part of the process of implementing the above embodiment method can be completed by a computer program to instruct related hardware, and the program can be stored in a computer readable storage medium, the program When executed, the flow of an embodiment of the methods as described above may be included. The storage medium may be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM).

The above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited thereto, and the equivalent changes made by the claims of the present invention are still within the scope of the present invention.

Claims

Rights request

1. A channel access method, characterized in that the method includes:

Confirm that random backoff is currently required based on channel conditions;

During the random backoff process, when the continuous channel monitoring time reaches the maximum continuous monitoring time T,, the first sleep with a duration of T _brcaM is performed, and the channel monitoring is stopped during the first sleep;

Continue to perform the random backoff after waking up from the first sleep;

Access the channel after completing the random backoff.

2. The channel access method according to claim 1, characterized in that, after confirming that random backoff is currently required according to the channel condition, the method includes:

Before starting to perform random backoff, obtain the current backoff time T _baek . _ff ;

If T _back . If _ff is greater than T _max , then the second sleep with a duration of T _brcak2 will be performed, and channel monitoring will be stopped during the second sleep;

Random backoff starts after waking up from the second sleep.

3. The channel access method according to claim 2, wherein starting to perform random backoff after waking up from the second sleep includes:

After waking up from the second sleep, the backoff time is recalculated, and random backoff is started based on the recalculated backoff time.

4. The channel access method according to claim 3, wherein the recalculation of the backoff time includes:

Reduce the size of the competition window used to determine the back-off time, and recalculate the back-off time through the reduced competition window.

5. The channel access method according to claim 3, wherein the recalculation of the backoff time includes:

Let the backoff time before the second sleep be T _baek . _ff , then the corresponding recalculated backoff time is rand(0, a*T _back . _ff ), where 0<a<2.

6. The channel access method according to any one of claims 3 to 5, characterized in that, before recalculating the backoff time, the method further includes:

Confirm that the current accumulated sleep time reaches the preset threshold.

7. The channel access method according to any one of claims 1 to 6, wherein continuing to perform random backoff after the first sleep wake-up includes:

After waking up from the first sleep, subtract the virtual backoff time T _v =p*T _breaM from the remaining backoff time, where p is the pre-estimated network busy probability.

8. The channel access method according to any one of claims 1 to 1, characterized in that, the T _breaM

=T _recover , where T _re∞ve r is the power recovery time determined based on the battery characteristic parameters or energy collection characteristic parameters of the communication device itself.

9. The channel access method according to any one of claims \~, characterized in that, before confirming the current need for random backoff according to the channel condition, the method further includes:

Get the T _breakl issued by the access point device.

10. The channel access method according to any one of claims 1 to 7, characterized in that before confirming the current need for random backoff according to the channel condition, the method further includes:

Get the reference recovery time T _w issued by the access point device;

The power recovery time ^T recover is determined based on the battery characteristic parameters or energy collection characteristic parameters of the communication device itself; ,

Determine T _break to be the smaller of 1^ and T _re∞VCT .

11. The channel access method according to claim 10, characterized in that the method further includes: modifying the maximum contention window parameter of the communication device according to R and T _re∞VCT .

12. The channel access method according to claim 11, wherein the modification of the maximum contention window parameter of the communication device according to R and T _recover includes:

Let the maximum competition window before modification of communication equipment be CW. , then the modified maximum competition window is

* -!, where k is the largest integer not larger than log ₂ (T _w /T _rec . _ver ).

13. A communication device, characterized in that the communication device includes:

Random backoff confirmation module, used to confirm the current need for random backoff based on channel conditions; Backoff module, used to perform random backoff;

The first sleep module is used to perform the first sleep with a duration of T _breakl when the continuous channel monitoring time reaches the maximum continuous monitoring time _Tmax during the random backoff process of the backoff module, and stop channel monitoring during the first sleep. After waking up from sleep, the backoff module is triggered to continue performing random backoff;

Access module, used to access the channel after random backoff is completed.

14. The communication device according to claim 13, characterized in that the communication device further includes: a second sleep module, configured to obtain the current back-off time T _back before the back-off module starts to perform random back-off. _ff , if T _back . If _ff is greater than T _max , the second sleep with a duration of T _break2 will be performed. Channel monitoring will be stopped during the second sleep. After waking up from the second sleep, the backoff module will be triggered to start performing random backoff.

15. The communication device according to claim 14, wherein the second sleep module includes:

Backoff time calculation unit, used to recalculate the backoff time;

The backoff trigger unit is used to trigger the backoff module to perform random backoff based on the recalculated backoff time.

16. The communication device according to claim 15, characterized in that the backoff time calculation unit is specifically used to:

The size of the competition window used to determine the backoff time is reduced, and the backoff time is recalculated based on the reduced competition window.

17. The communication device according to claim 15, characterized in that the back-off time calculation unit is specifically used to:

Let the backoff time before the second sleep be T _baek . _ff , then the corresponding recalculated backoff time is rand(0, a* T _backoff ), where 0<a<2 ₍

18. The communication device according to any one of claims 15 to 17, characterized in that the second sleep module further includes:

The sleep accumulation threshold unit is used to trigger the back-off time calculation unit to recalculate the back-off time when the current accumulated sleep time reaches the preset threshold.

19. The communication device according to any one of claims 13 to 18, characterized in that the first sleep module includes:

The virtual backoff calculation unit is used to subtract the virtual backoff time T _v =p* T _breakl from the remaining backoff time after the first sleep wake-up, where p is the pre-estimated network busy probability.

20. The communication device according to any one of claims 13 to 19, wherein the T,

=T _recover , where T _re∞ve r is the power recovery time determined based on the battery characteristic parameters or energy collection characteristics of the communication device itself.

21. The communication device according to any one of claims 13 to 19, characterized in that the first sleep module includes:

The first sleep time acquisition unit is used to acquire T _breakl issued by the access point device.

22. The communication device according to any one of claims 13 to 19, characterized in that the first sleep module includes:

The second sleep time acquisition unit is used to obtain the reference recovery time T _w issued by the access point device, the power recovery time T _recover determined according to the battery characteristic parameters or energy collection characteristic parameters of the communication device itself, and determine T _break to be T _w and the smaller value in T recover.

23. The communication device according to claim 22, wherein the first sleep module further includes:

The competition window modification unit is used to modify the maximum competition window parameter of the communication device according to 1^ and T _re∞w .

24. The communication device according to claim 23, wherein the contention window modification module is specifically used for:

25. A communication device, characterized in that it includes: a receiving module, a sending module, a memory and a processor, wherein a set of program codes is stored in the memory, and the processor is used to call the program code stored in the memory to perform the following operate:

Confirm that random backoff is currently required based on the channel conditions monitored by the receiving module;

During the random backoff process, when the continuous channel monitoring time reaches the maximum continuous monitoring time T _max , the first sleep with a duration of T _breaM is performed. The receiving module stops channel monitoring during the first sleep; randomization continues after waking up from the first sleep. retreat; retreat

26. The communication device according to claim 25, wherein the processor performs the following operations after confirming that random backoff is currently required based on the channel condition of the monitoring receiving module: before starting to perform random backoff, obtain the current The backoff time T _baek . _ff ;

If T _b¾;k . If ff is greater than ^T _max , then the second sleep with a duration of T _break2 will be performed. During the second sleep, the receiving module stops channel monitoring;

The random backoff starts after waking up from the second sleep state.

27. The communication device according to claim 26, wherein the processor wakes up after executing sleep T _break2 , starts channel monitoring and starts performing random backoff operations, including:

28. The communication device according to claim 27, wherein the processor performs an operation of recalculating the backoff time, including:

29. The communication device according to claim 27, wherein the processor performs an operation of recalculating the backoff time, including:

Let the backoff time before the second sleep be T _baek . _ff , then the corresponding recalculated backoff time is rand(0, a* T _back . _ff ), where 0<a<2.

30. The communication device according to any one of claims 27 to 29, wherein the processor also performs the following operations before performing the operation of recalculating the backoff time:

Confirm that the current accumulated sleep time reaches the preset threshold.

31. The communication device according to any one of claims 25 to 30, wherein the processor continues to perform random backoff operations after performing the first sleep wake-up, including:

32. The communication device according to any one of claims 25 to 31, wherein T _breakl =T _recover , wherein T _re∞ver is a battery characteristic parameter or an energy collection characteristic parameter according to the communication device itself. Determined battery recovery time.

33. The communication device according to any one of claims 25 to 31, characterized in that, before the processor performs the operation of confirming that random backoff is currently required according to the channel condition, it also performs the following operations: Obtaining through the receiving module T _breaM delivered by the access point device.

34. The communication device according to any one of claims 25 to 31, characterized in that: the processing The device also performs the following operations before performing the operation of confirming that random backoff is currently required according to the channel condition: Obtaining the reference recovery time T _w issued by the access point device through the receiving module;

Determine T _break to be the smaller of 1^ and T _re∞ .

35. The communication device according to claim 34, wherein the processor is further configured to perform the following operations:

Modify the maximum competition window parameters of the communication equipment according to 1^ and T _re∞ .

36. The communication device according to claim 35, wherein the processor performs an operation of modifying the maximum contention window parameter of the communication device according to _Tw and _Tver , including: