Summary of the invention
The embodiment of the present invention provides a kind of method of controlling transmission rate and equipment, can make transmitting terminal select corresponding control strategy according to different interference environments.
The embodiment of the present invention provides a kind of method of controlling transmission rate, comprising:
Transmitting terminal obtains frame in the first Preset Time and sends the fluctuation parameters of success rate, and is adjusted at frame transmission success rate p in these many speed re-transmission MRR according to the fluctuation parameters getting
nweight α;
Transmitting terminal is used respectively α and 1-α to p
nsend success rate P with the smoothed frame at upper once MRR
n-1compute weighted, obtain sending success rate P at the smoothed frame of this MRR
n;
Transmitting terminal is according to P
ndetermine the transmission rate of using at next MRR.
Preferably, transmitting terminal is according to P
ndetermine that the transmission rate of using at next MRR specifically comprises:
As transmitting terminal judgement P
nwhile being greater than credit rise threshold value, rise credit is added to 1, and judge when rise credit is greater than present rate rise threshold value, raise the transmission rate that next MRR is used.
Preferably, before described transmitting terminal raises the transmission rate of next MRR use, described method also comprises:
When the judgement of described transmitting terminal is last when adjusting being operating as of transmission rate and raising transmission rate, get 1/2nd higher values that raise in threshold value with minimum-rate that described present rate raises threshold value and raise threshold value as next speed; And/or,
When being operating as of the last adjustment of transmitting terminal judgement transmission rate lowered transmission rate, 2 times of smaller values that raise in threshold value with maximum rate getting described present rate rise threshold value raise threshold value as next speed.
Preferably, described transmitting terminal raises the transmission rate that next MRR is used, and specifically comprises:
Described transmitting terminal judges whether to dwindle protection interval, if so, dwindles protection interval; If not, judge whether to increase the number of multiple-input, multiple-output MIMO stream, if so, increase the number of MIMO stream, if not, increase the index value of modulation and coding strategy MCS.
Preferably, described transmitting terminal is according to P
ndetermine the transmission rate of using at next MRR, specifically comprise:
When described transmitting terminal raises the transmission rate of next MRR use, the most high-grade transmission rate of this MRR is raised, and a shelves transmission rate that this MRR is used is as the a+1 shelves transmission rate of next MRR use; And/or,
When described transmitting terminal is lowered the transmission rate of next MRR use, described transmitting terminal is used the b shelves transmission rate of using at this MRR b-1 transmission rate as next MRR; And the last step transmission rate of next MRR is lowered, wherein, a >=1, b >=2.
Preferably, described method also comprises:
Transmitting terminal, when this MRR finishes, calculates the corresponding frame transmission of each grade of speed success rate that this MRR is used;
Described transmitting terminal obtains the fluctuation parameters of frame transmission success rate in the first Preset Time, specifically comprises:
Described transmitting terminal obtains the fluctuation parameters that the most high-grade transmission rate r0 that this MRR the uses frame in the first Preset Time sends success rate.
Preferably, described transmitting terminal calculates the corresponding frame transmission of each grade of speed success rate that this MRR is used, and specifically comprises:
If complete the transmission of data in this MRR with x+1 shelves transmission rate rx, described transmitting terminal is got x+1 shelves transmission rate p
rx, n=send successful number of sub-frames/(in aggregate frame, number of sub-frames * is in the transmission times of x+1 shelves); The corresponding frame transmission of each grade of transmission rate success rate of getting higher than transmission rate rx is 0, and the corresponding frame of y+1 shelves transmission rate ry of getting lower than transmission rate rx sends success rate p
ry, n=p
r(y-1), n* 0.875+0.125.
The embodiment of the present invention also provides a kind of sending rate control equipment, as transmitting terminal, is applied to, in wireless network, comprising:
Adjusting module, sends the fluctuation parameters of success rate for obtaining frame in the first Preset Time, and is adjusted at frame transmission success rate p in these many speed re-transmission MRR according to the fluctuation parameters getting
nweight α;
Computing module, for being used respectively α and 1-α to p
nsend success rate P with the smoothed frame at upper once MRR
n-1compute weighted, obtain sending success rate P at the smoothed frame of this MRR
n;
Speed control module, for the P obtaining according to computing module
ndetermine the transmission rate of using at next MRR.
Preferably, described speed control module comprises:
Raise submodule, while raising for determining in described speed control module the transmission rate of using at next MRR, judge whether to dwindle protection interval, if so, dwindle protection interval; If not, judge whether to increase the number of multiple-input, multiple-output MIMO stream, if so, increase the number of MIMO stream, if not, increase the index value of modulation and coding strategy MCS.
Preferably, described computing module also for transmitting terminal when this MRR completes the transmission of data with x+1 shelves transmission rate rx, get x+1 shelves transmission rate p
rx, n=send successful number of sub-frames/(in aggregate frame, number of sub-frames * is in the transmission times of x+1 shelves); The corresponding frame transmission of each grade of transmission rate success rate of getting higher than transmission rate rx is 0, and the corresponding frame of y+1 shelves transmission rate ry of getting lower than transmission rate rx sends success rate p
ry, n=p
r (y-1), n* 0.875+0.125.
In the embodiment of the present invention, make transmitting terminal obtain the fluctuation parameters of frame transmission success rate in the first Preset Time, and adjust the proportion of this MRR frame transmission success rate in smoothed frame transmission success rate according to fluctuation parameters, and the smoothed frame before corresponding adjustment sends the proportion in success rate, the speed that sends the fluctuation of success rate due to frame can be reflected in the speed of the variation being disturbed in current wireless environment, transmitting terminal can be according to the speed of interference variations, adjust respectively present frame and send success rate and the frame transmission success rate shared proportion in this MRR frame smoothly sends success rate in a plurality of MRR before, if present frame is sent to the shared proportion of success rate to raise, can improve the sensitivity that transmitting terminal carries out speed adjustment, accordingly, if the smoothed frame in a upper MRR is sent to the shared proportion of success rate to raise, can reduce the sensitivity that transmitting terminal carries out speed adjustment.In this way, the sensitivity level that can make transmitting terminal adjust according to the adaptive speed control of current wireless environment, better adapts to current wireless environment.In addition, in the embodiment of the present invention, because smoothed frame with reference in a upper MRR sends success rate, can avoid transmitting terminal when the transmission rate of selecting next MRR to use completely the frame with reference to this MRR send success rate, eliminated to a certain extent the impact of burr on transmission rate.
Embodiment
Below in conjunction with drawings and Examples, the specific embodiment of the present invention is further described.Following examples are only for technical scheme of the present invention is more clearly described, and can not limit the scope of the invention with this.
The embodiment of the present invention provides a kind of control method of transmission rate, and in the wireless environment that application is comprised of access point AP and client, as shown in Figure 1, the method comprises:
Step 101, transmitting terminal obtains frame in the first Preset Time and sends the fluctuation parameters of success rate, and is adjusted at frame transmission success rate p in these many speed re-transmission MRR according to the fluctuation parameters getting
nweight α.
In this step, frame sends success rate and refers in certain measurement period, the ratio between total number of the Frame that the number of the Frame that receiving terminal successfully receives and transmitting terminal send.Such as, in many speed MRR mechanism, if sending just receiving end through 2 times, a Frame successfully receives, the number of the Frame that receiving terminal receives is 1, total number of the Frame that transmitting terminal sends is 2, and, in this MRR, it is 50% that frame sends success rate.That obtains that frame sends success rate specifically has numerous embodiments in the prior art, does not repeat them here.
Frame sends the fluctuation parameters of success rate, it is the parameter that is reflected in the fluctuation situation of the transmission of the frame in each sampling window success rate in a period of time, if each difference that adopts the frame in window to send between success rate is larger, think that fluctuation is larger, if frame sends success rate and all approaches mean value, think that fluctuation is less.
After getting the fluctuation parameters of frame transmission success rate, the frame that transmitting terminal is adjusted in this MRR sends success rate p
nweight α, according to frame in the first Preset Time, send the fluctuation situation of success rate, determine that the frame in this MRR sends success rate p
nweight α, if such as fluctuation is larger, the α that raises, otherwise reduce α etc.In practical application; difference according to designer to the definition of fluctuation parameters and demand; the mode that α is adjusted is also not quite similar, and specifically how fluctuation parameters is defined, and How to choose is adjusted accordingly strategy and do not affected protection scope of the present invention.
In this step, think that the current residing MRR of transmitting terminal is n MRR, a corresponding upper MRR and next MRR are respectively n-1 and n+1 MRR.
Step 102, transmitting terminal is used respectively α and 1-α to p
nsend success rate P with the smoothed frame at upper once MRR
n-1compute weighted, obtain sending success rate P at the smoothed frame of this MRR
n.
Here level and smooth with in prior art with prior art in level and smooth meaning consistent, all refer to that some parameters of reference revise the current parameter obtaining.Smoothed frame in this step sends success rate and just refers to that with reference to the smoothed frame at upper once MRR, sending success rate revises the frame transmission success rate of this MRR, obtain sending success rate at the smoothed frame of this MRR, when calculating smoothed frame transmission success rate, can send success rate in conjunction with smoothed frame in the past like this.
Step 103, transmitting terminal is according to P
ndetermine the transmission rate of using at next MRR.
In this step, transmitting terminal is according to P
ndetermine that the transmission rate of using at next MRR is consistent with prior art, if judgement smoothed frame sends success rate P
nhigher than a certain set point, raise the transmission rate that next MRR is used, or at judgement P
nlower than a certain set point, in the transmission rate of lowering next MRR use.
In the embodiment of the present invention, make MRR obtain the fluctuation parameters of frame transmission success rate in a period of time, and according to the frame that the fluctuation parameters getting is adjusted this MRR, send success rate and send shared proportion in success rate at smoothed frame, and then the frame after using this level and smooth sends success rate as the foundation of determining the transmission rate that next MRR is used.It will be appreciated by those skilled in the art that, the speed that sends the fluctuation of success rate due to frame can be reflected in the speed of the variation being disturbed in current wireless environment, transmitting terminal can, according to the speed of interference variations, be adjusted the frame transmission success rate that present frame transmission success rate and a plurality of MMR are before corresponding and smoothly send the proportion in success rate at the smoothed frame of this MRR.Such as, fast if wireless channel environment changes, present frame is sent to success rate proportion and raise; If contrary wireless channel environment changes slow, present frame is sent to success rate proportion and reduce.In this way, the sensitivity level that can make transmitting terminal control according to the adaptive adjustment speed of current wireless environment, better adapts to current wireless environment.In addition, in the embodiment of the present invention, because the smoothed frame with reference in a upper MRR sends success rate, can avoid transmitting terminal when selecting the transmission rate of next MRR, to using the frame of this MRR completely and send success rate as basis for estimation, eliminate to a certain extent the impact of burr on transmission rate.
Preferably, the mode of obtaining the fluctuation parameters of frame transmission success rate in above-mentioned steps 101 can send success rate for the frame that transmitting terminal obtain in each sampling window in the first Preset Time, and the variance yields of getting the frame transmission success rate getting is as fluctuation parameters.
Preferably, in above-mentioned steps 101, the frame that transmitting terminal is adjusted in this MRR according to the fluctuation parameters getting sends success rate p
nweight, can be: transmitting terminal judges whether fluctuation parameters is greater than the first preset value, if so, increases α, as no, judge whether fluctuation parameters is less than the second preset value, if so, reduce α, if not, maintain α constant; Or transmitting terminal judges whether fluctuation parameters is less than the 3rd preset value, if so, increases α, as no, judge whether fluctuation parameters is greater than the 4th preset value, if so, reduces α, if not, maintains α constant.In practical application, different according to the fluctuation parameters that those skilled in the art are selected, the strategy of adjusting α also may be different.Such as, if fluctuation parameters is above-mentioned variance, when fluctuation parameters is greater than the first preset value, should raise α, corresponding, while being less than the second preset value, lower α, in this way, can make transmitting terminal when fluctuation is larger, more with reference to current frame transmission success rate, the sensitivity of advancing the speed and adjusting, and less in fluctuation, before more reference, the frame of one end time sends success rate, the sensitivity that changing down is adjusted, guarantees the stable of wireless link.Above-mentioned the first preset value, the second preset value, the 3rd preset value, the 4th preset value can be set as required, do not repeat them here.
Preferably, after transmitting terminal initialization, the value that can make transmitting terminal get α is 1.Due to after transmitting terminal initialization, while carrying out for the first time MRR, the smoothed frame of last MRR that can reference sends success rate, in the embodiment of the present invention, after transmitting terminal initialization, the frame of MRR for the first time of only usining sends success rate and sends success rate as the smoothed frame of MRR for the first time.
Preferably, transmitting terminal is according to P
ndetermine that the transmission rate of using at next MRR can comprise: as transmitting terminal judgement P
nwhile being greater than credit rise threshold value, rise credit is added to 1, and judge when rise credit is greater than present rate rise threshold value, raise the transmission rate that next MRR is used.Concrete, can set in advance a speed and raise threshold value, it is with respect to the threshold value that raises credit value that this speed raises threshold value, raise credit value when reaching this speed and raising threshold value, raise the transmission rate that next MRR is used, and after raising transmission rate, by current rise credit zero clearing.Same, a credit is set and raises threshold value, it is with respect to the threshold value that sends success rate that this credit raises threshold value, when the frame that transmitting terminal obtains smoothly sends success rate and is greater than certain transmission success rate, rise credit is added to 1.Due in actual applications, may be because MRR(single or lesser amt within a period of time is such as below 10) in frame send that success rate is too high to be caused smoothed frame to send success rate raising fast, and the MRR of single or lesser amt can not illustrate that current wireless environment takes a turn for the better, that is to say, current wireless environment may not support transmitting terminal to use higher transmission rate.Therefore, in the embodiment of the present invention, when smoothed frame transmission success rate is greater than certain threshold value, directly do not raise frame and send success rate, to raise accordingly credit and add 1, and raise credit when being greater than speed and raising threshold value (this speed raises threshold value and is greater than 1) in judgement, just raise frame and send success rate, thereby avoid that smoothed frame transmission success rate because of MRR is individually too high causes the irrational rise of transmission rate.In addition, in embodiments of the present invention, if transmitting terminal judgement P
nbe not more than credit rising threshold value, can also make transmitting terminal judgement P
nwhether be less than speed and lower threshold value, if so, lower the transmission rate that next MRR is used.In practical application, when frame transmission success rate corresponding to current transmission rate is too low, in order to guarantee user's transceiving data normally, should in time transmission rate be lowered, therefore, when judgement success rate is less than certain critical value (speed downward threshold value), directly lowers, and can totally not lower credit value.
Preferably, can also adjust dynamically transmission rate and raise the required speed rise threshold value reaching, in the preferred embodiment of the invention, can make at transmitting terminal after judgement rise credit is greater than present rate rise threshold value, before raising the transmission rate of next MRR use, judgement is last in the second Preset Time adjusts being operating as while raising transmission rate of transmission rate, gets 1/2nd higher values that raise in threshold value with minimum-rate that present rate raises threshold value and raises threshold value as next speed.In practical application, if transmitting terminal raises transmission rate within a short period of time continuously, illustrate that current residing wireless environment is better, now can impel by certain Encourage the mechanism transmitting terminal to raise transmission rate.In the embodiment of the present invention, the operation of the last adjustment transmission rate of carrying out in the second Preset Time be also on timing, the present rate of current use is raised to threshold value to be lowered, can make in this way transmitting terminal when 1/2nd of present rate rise threshold value is greater than minimum-rate rise threshold value, more easily raise speed, but for fear of speed, raise threshold value infinitesimal, need to set a rational minimum preset value.
Accordingly, if transmitting terminal in judgement in the 3rd Preset Time before this MRR last adjust transmission rate be operating as the most high-grade transmission rate of downward, transmitting terminal downward very soon after raising transmission rate is described, very be not applicable to sending data with the transmission rate after raising, now, 2 times of smaller values that raise in threshold value with maximum rate getting described present rate rise threshold value raise threshold value as next speed.In this way, in speed, raise 2 times of threshold value and be less than before maximum rate raises threshold value, can increase the difficulty that raises transmission rate, same, a maximum rate is set and raises threshold value to prevent that speed from raising threshold value infinitely great.
In the embodiment of the present invention, when transmitting terminal is determined while need to raise transmission rate, can be preferably according to method as shown in Figure 2, regulate:
Step 201, transmitting terminal judges whether to adopt the mode of dwindling protection interval to raise, and if so, turns to step 202, if not, turns to step 203.
Step 202, transmitting terminal dwindles the protection interval that sends data.
Step 203, transmitting terminal judges whether that the number that can increase multiple-input, multiple-output MIMO stream improves transmission rate, if so, turns to step 204, if not, turns to step 205
Step 204, transmitting terminal increases the number of MIMO stream.
Step 205, transmitting terminal increases the index value of modulation and coding strategy MCS.
In realizing process of the present invention, present inventor finds, increasing MIMO stream may cause transmission rate to raise unsuccessfully because of the interference between the transmitting antenna increasing, the mode that increases MCS index value may cause receiving terminal correctly demodulation and/or decoding, so preferential mode of selecting SGI in the embodiment of the present invention, by SGI cannot on while being transferred to corresponding speed, select the mode of MIMO, when MIMO mode is also not too applicable to current wireless environment (such as those skilled in the art find, the number that increases MIMO stream causes current interference of receiving significantly to strengthen, and reduce while significantly recovering after the number of MIMO stream), by increasing the mode of MCS index value, raise transmission rate.In this way, can improve to greatest extent the success rate that raises transmission rate.
Preferably, when transmitting terminal is according to P
nwhile determining the transmission rate that need to raise next MRR use, the most high-grade transmission rate of this MRR is raised, and a shelves transmission rate that this MRR is used is as the a+1 shelves transmission rate of next MRR use; And/or, when transmitting terminal is according to P
nwhile determining the transmission rate that need to lower next MRR use, described transmitting terminal is used the b shelves transmission rate of using at this MRR b-1 transmission rate as next MRR; And the last step transmission rate of next MRR is lowered, wherein, a>=1, b>=2.In this way, in the time of can making transmitting terminal adopt the most high-grade transmission rate after rise to send data after raising speed, the most high-grade transmission rate before adopting completes the transmission of data as early as possible, and if after frame corresponding to the most high-grade transmission rate of transmitting terminal before need to obtaining send success rate, it is also more accurate that the frame getting sends success rate.Wherein, in the invention process in involved each grade of transmission rate, first grade of transmission rate is the transmission rate that transmitting terminal is used at first in a MRR, i.e. the most high-grade transmission rate, second gear transmission rate is the transmission rate that transmitting terminal is selected after using first grade of transmission rate to send unsuccessfully, third gear transmission rate is the transmission rate that transmitting terminal is selected after using second gear transmission rate to send unsuccessfully, the like, deep low gear transmission rate is last transmission rate that transmitting terminal is selected in a MRR, if transmitting terminal is after number of retransmissions corresponding to deep low gear transmission rate used up, still data are not sent, abandon this time sending, this MRR finishes.
As pointed in background technology, in 802.11, generally adopt MRR mechanism to carry out the transmission of data, MRR can adopt the transmission rate of many grades (normally 4 grades), and in transmission and the re-transmission of each grade of enterprising row data of transmission rate.If sent when adopting a certain shelves speed, to send successful speed be transmission times/mono-to corresponding frame, such as altogether having carried out 5 times, sends, and to send success rate be 20% to the frame of this MRR.But this mode, can not truly reflect whether certain grade of transmission rate is wherein applicable to current wireless environment.Such as, if in the most high-grade transmission rate, after sending twice, still do not send successfully, and once just send successfully in second gear transmission rate, now the most high-grade transmission rate of explanation is not suitable for current wireless environment, but second gear transmission rate is relatively applicable to current wireless environment, and according to account form of the prior art, can not well reflect this situation.In order to address this problem, in the embodiment of the present invention also when each MRR finishes, calculate respectively the corresponding frame of each grade of transmission rate and send success rate, and make transmitting terminal obtain the fluctuation parameters that the most high-grade transmission rate r0 that this MRR the uses frame in the first Preset Time sends success rate.Owing to all having calculated each grade of corresponding frame of transmission rate after each MMR, send success rate, the corresponding success rate of certain transmission rate that transmitting terminal obtains is more accurate, by getting frame corresponding to fixing speed, send the fluctuation parameters of success rate simultaneously, can reflect more really the situation of change of wireless environment.In addition, if adopt too high or too low transmission rate, the fluctuation parameters that possibly cannot accurately reflect transmission rate, such as the speed adopting is too high, in possible a period of time, its corresponding frame transmission success rate is 0 entirely, if too low, may its corresponding frame transmission success rate be 1 entirely, in the embodiment of the present invention, select the fluctuation parameters of the frame transmission success rate that the most high-grade current adopted speed r0 is corresponding, can better reflect the truth of wireless environment.
In practical application, the mode of calculating the frame transmission success rate of transmission rate r0 in this MRR is consistent with prior art, does not repeat them here.If in other MRR, also selected r0 as wherein one grade as transmission rate, transmitting terminal can calculate in the following way the corresponding frame of each grade of speed that this MRR uses and send success rate, and then transmission success rate corresponding to definite r0:
If complete the transmission of data in this MRR with x+1 shelves transmission rate rx, transmitting terminal is got x+1 shelves transmission rate p
rx, n=send successful number of sub-frames/(in aggregate frame, number of sub-frames * is in the transmission times of x+1 shelves); The corresponding frame transmission of each grade of transmission rate success rate of getting higher than transmission rate rx is 0, and the corresponding frame of y+1 shelves transmission rate ry of getting lower than transmission rate rx sends success rate p
ry, n=p
r(y-1), n* 0.875+0.125.Such as, in this MRR, data send with second gear transmission rate the most at last, and send successfully after 2 times retransmit at second gear, first grade of frame transmission success rate corresponding to transmission rate is 0, it is that 1/ (1*3)=33%(supposes that the number of aggregate frame is 1 that frame corresponding to second gear transmission rate sends success rate), it is 33%*0.875+0.125=41% that frame corresponding to third gear transmission rate sends success rate, and it is 41%*0.875+0.125=49% that fourth speed sends frame transmission success rate corresponding to success rate.Present inventor is finding can reflect that in the result of calculating by above-mentioned account form the frame of each grade of transmission rate sends success rate according to a large amount of experiments and statistics.
In practical application, for frame corresponding to the r0 that guarantees to get sends the accuracy of success rate, can make transmitting terminal only get to use r0 as the MRR of one grade of transmission rate wherein as sampling window, or, when adopting r0 very few as the MRR quantity of one grade of transmission rate wherein (while being less than preset value), select other lower transmission rates fluctuation parameters that in each MRR, frame sends success rate in the first Preset Time as the foundation of adjusting weight α.
Preferably, in embodiments of the present invention, in the time of can also making client be linked in AP, make transmitting terminal and receiving terminal (, make AP and wireless client, or wireless client and AP) consult transmission rate, and make AP and wireless client all store the transmission rate that both sides can both support, after when needing to raise or lowering transmission rate, the transmission rate of selecting a speed to use as next MRR from the transmission rate of storage.This negotiations process is consistent with prior art, does not repeat them here.
Below in conjunction with concrete scene, the method of rate control that the embodiment of the present invention is provided is elaborated, in the embodiment of the present invention, suppose that transmitting terminal is AP, receiving terminal is client, the fourth gear transmission rate that this (the 50th time) MRR adopts is respectively 104Mbps, 78Mbps, 52Mbps and 39Mbps, and the method for rate control that the embodiment of the present invention provides can comprise each step as shown in Figure 3:
Step 301, AP obtains the current point in time frame transmission success rate of transmission rate correspondence in each MRR of the interior 104Mbps of 5s before.
In practical application, AP also can be from choosing the MRR of some in a period of time before at random, and the transmission success rate of the transmission rate of obtaining 104Mbps in the MRR choosing, or the success rate of the transmission rate of 104Mbps in some sampling windows in 5s before choosing.
Make the time point of AP execution step 301 have multiple choices, in the preferred embodiment of the invention, can make AP when this MRR finishes, perform step 301 step.
Step 302, AP obtains the variance yields that each frame getting sends success rate.
Step 303, whether the variance yields that AP judgement gets is greater than the first preset value; If so, turn to step 304, if not, turn to step 305.
Step 304, speed corresponding frame in this MRR that AP raises 104Mbps sends the shared weight α of success rate, turns to afterwards step 307.
Step 305, whether the variance yields that AP judgement gets is less than the second preset value, if so, turns to step 306, if not, turns to step 307.
Step 306, speed corresponding frame in this MRR that AP lowers 104Mbps sends the shared weight α of success rate, turns to afterwards step 307.
Step 307, AP is used α and 1-α to send success rate p to the speed of 104Mbps corresponding frame in this MRR
50send success rate P with speed corresponding smoothed frame in the 49th MRR of 104Mbps
49compute weighted, the smoothed frame of the speed that obtains 104Mbps in this MRR sends success rate P
50.
Step 308, AP judges P
50whether be greater than credit and raise threshold value, if so, turn to step 309; If not, turn to step 313.
Step 309, AP adds 1 by rise credit, and judgement raises credit and whether be greater than speed and raise threshold value, if so, turns to step 310, if not, process ends.
Step 310, the 51st the most high-grade transmission rate that MRR is used of AP, and using 104Mbps, 78Mbps, 52Mbps respectively as the 51st MRR second and third, fourth gear transmission rate, turn to afterwards step 311.
Step 311, adjusts whether the operation of high-grade transmission rate is to raise transmission rate for the last time in the second Preset Time before AP judgement, if so, turns to step 312; If not, process ends.
Step 312, AP gets 1/2nd higher values that raise in threshold value with minimum-rate that present rate raises threshold value and raises threshold value as next speed.
In practical application, if AP raises continuously in the regular hour, illustrate that the current residing wireless environment of transmitting terminal is better, now should encourage AP to continue to raise.Before present rate rise threshold value is greater than minimum-rate rise threshold value, AP always smoothed frame can be sent to success rate and present rate rise threshold value compares, along with present rate raises threshold value, diminish gradually, the threshold value that AP raises smoothed frame transmission success rate is also more and more lower.
Step 313, AP judges P
5whether be less than present rate and lower threshold value, if so, turn to step 314, if not, process ends.
Step 314, AP judges in the 3rd Preset Time before this MRR, whether the last operation of adjusting transmission rate is to lower the most high-grade transmission rate, if so, turns to step 315, if not, turns to step 316.
Step 315,2 times of smaller values that raise in threshold value with maximum rate that AP gets present rate rise threshold value raise threshold value as the next one, turn to afterwards step 316.
In practical application, if be to raise transmission rate to the adjustment of transmission rate for the last time in the current short period of distance, and this is lowered, and illustrates that the smoothed frame success rate of the transmission rate after raising is lower.After lowering for fear of this, the smoothed frame success rate of transmitting terminal after judgement is lowered will be adjusted to the transmission rate that success rate is lower after being greater than and raising threshold value again in transmission rate, in this step, get two times and the maximum smaller value raising in threshold value raising threshold value, like this before current rise threshold value is less than maximum rise threshold value, it is more and more higher that the needed smoothed frame of transmitting terminal rise transmission rate sends success rate, just can limit to a certain extent in this way transmitting terminal the higher lower transmission rate of success rate and success rate lower compared with high transmission rate between repeatedly jump, thereby it is stable to guarantee that client connects.Same is wireless large for fear of rise threshold value, and a reasonably maximum threshold value that raises need to be set.
Step 316, the most high-grade transmission rate that AP is used the 51st MRR is adjusted into 78Mbps, simultaneously will be two, three, fourth gear transmission rate is adjusted into respectively 52Mbps and 39Mbps, 24Mbps.
Design based on same, the embodiment of the present invention also provides a kind of sending rate control equipment, and as shown in Figure 4, this equipment comprises:
Adjusting module 401, sends the fluctuation parameters of success rate for obtaining frame in the first Preset Time, and is adjusted at frame transmission success rate p in these many speed re-transmission MRR according to the fluctuation parameters getting
nweight α;
Computing module 402, with using respectively α and 1-α to p
nsend success rate P with the smoothed frame at upper once MRR
n-1compute weighted, obtain sending success rate P at the smoothed frame of this MRR;
Speed control module 403, for according to P
ndetermine the transmission rate of using at next MRR.
Preferably, adjusting module 401 comprises:
Calculating sub module 4011, for the frame obtaining in each sampling window in the first Preset Time, send success rate, and calculate the frame get and send the variance yields of success rate, and obtain variance yields and as the frame in the first Preset Time, send the fluctuation parameters of success rate.
Adjusting module 401 also comprises: adjust submodule 4012, for judging whether fluctuation parameters is greater than the first preset value, if so, increase α, as no, judge whether fluctuation parameters is less than the second preset value, if so, reduce α, if not, maintain α constant;
Or, judge whether fluctuation parameters is less than the 3rd preset value, if so, increases α, as no, judge whether fluctuation parameters is greater than the 4th preset value, if so, reduces α, if not, maintains α constant.
Preferably, adjusting module 401 also for getting α=1 after transmitting terminal initialization.
Preferably, specifically for the most high-grade transmission rate r0 that obtains this MRR and use, the frame in the first Preset Time sends the fluctuation parameters of success rate to adjusting module 401.
Preferably, computing module 402, also for transmitting terminal when this MRR completes the transmission of data with x+1 shelves transmission rate rx, get x+1 shelves transmission rate p
rx, n=send successful number of sub-frames/(in aggregate frame, number of sub-frames * is in the transmission times of x+1 shelves); The corresponding frame transmission of each grade of transmission rate success rate of getting higher than transmission rate rx is 0, and the corresponding frame of y+1 shelves transmission rate ry of getting lower than transmission rate rx sends success rate p
ry, n=p
r (y-1), n* 0.875+0.125.
Preferably, speed control module 403 also comprises: raise submodule 4031, while raising for determining in speed control module 403 transmission rate of using at next MRR, judge whether to dwindle protection interval, if so, dwindle protection interval; If not, judge whether to increase the number of multiple-input, multiple-output MIMO stream, if so, increase the number of MIMO stream, if not, increase the index value of modulation and coding strategy MCS.
Preferably, speed control module 403 is also for after raising the most high-grade transmission rate of using in the next one transmission cycle, using the a+1 shelves transmission rate of using as the next one transmission cycle in a shelves transmission rate of this MRR use; Or, after lowering the most high-grade transmission rate of using in the next one transmission cycle, the b-1 transmission rate that the b shelves transmission rate of using at this MRR was used as the next one transmission cycle; Wherein, a >=1, b >=2.
Preferably, this equipment also comprises: threshold value adjusting module 404, raise the transmission rate of next MRR use for speed control module 403 before, and transmitting terminal judgement is last adjusts being operating as while raising transmission rate of transmission rate, get 1/2nd higher values that raise in threshold value with minimum-rate that described present rate raises threshold value and raise threshold value as next speed; And/or and transmitting terminal judgement is last adjusts being operating as while lowering transmission rate of transmission rate, gets 2 times of smaller values that raise in threshold value with maximum rate that described present rate raises threshold value and raise threshold value as next speed.
The above is only the preferred embodiment of the present invention; it should be pointed out that for those skilled in the art, do not departing under the prerequisite of the technology of the present invention principle; can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.