CN103327640B - The medium reservation method based on competition that in WLAN (wireless local area network), multicast transmits and device - Google Patents
The medium reservation method based on competition that in WLAN (wireless local area network), multicast transmits and device Download PDFInfo
- Publication number
- CN103327640B CN103327640B CN201310246764.4A CN201310246764A CN103327640B CN 103327640 B CN103327640 B CN 103327640B CN 201310246764 A CN201310246764 A CN 201310246764A CN 103327640 B CN103327640 B CN 103327640B
- Authority
- CN
- China
- Prior art keywords
- frame
- message
- medium
- sta
- allocation vector
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Mobile Radio Communication Systems (AREA)
Abstract
Describe a kind of method and apparatus, it comprises: receive described message by the station of addressing non-in the message for reserved communication medium; Determine whether the network allocation vector received in described message has the value being greater than current network allocation vector; Determine whether to detect in the transmission of interim time on described communication media; And determine in response to for the described of transmission, described current network allocation vector is reset.Also describe a kind of method and apparatus, it comprises: receive the response for described message by the station of addressing non-in the message for reserved communication medium; Determine whether the network allocation vector in described response is greater than current network allocation vector; And determine in response to described, upgrade described current network allocation vector.
Description
The divisional application that the application is the applying date is on 06 18th, 2008, application number is 200880129930.X, denomination of invention is the patent application of " medium reservation method based on competition transmitted for multicast in WLAN (wireless local area network) and device ".
Technical field
Present invention relates in general to radio communication, particularly, relate to a kind of method and apparatus of the collision probability for reducing multicast in WLAN (wireless local area network).
Background technology
As used herein, "/" represents the alternative title for identical and similar assembly or structure.That is, "/" can be considered as referring to " or ", as used herein.Clean culture is between single transmitter/conveyer and single receiver.It is between all receivers in the range of receiving of single transmitter/conveyer and conveyer that broadcast transmits.Multicast transmission is that between the subset of receiver in the range of receiving of single transmitter/conveyer and conveyer, wherein, this subset of the receiver in the range of receiving of conveyer can be whole subset.That is, multicast can comprise broadcast, is therefore the term more wide in range than broadcast, as used herein.Data transmit in the mode of grouping or frame.
In a wireless local area network, keeping out of the way that (backoff) time uses physics and virtual carrier process and after determining wireless medium/channel idle/unimpeded, access point (AP)/stand (STA)/mobile device/mobile terminal transmits multicast and broadcast frame immediately with random.Therefore, when multiple STA attempts to transmit simultaneously time, conflict may be there is.Such as, access point and its STA be associated may transmit simultaneously, and the frame of then all transmission is lost due to conflict.Such as, when multicast data frame is sent to its some STA be associated by AP, its data or control frame can be sent to AP by another STA.AP is referred to as Basic Service Set (BSS) together with the station that it is associated.The conflict appeared within BSS is referred to as conflict in BSS.In another example, AP1 and AP2 is operated in same channel/frequency, and two BSS overlaps.Frame is sent to its STA be associated by AP1.But AP2 can not the transmission of uppick AP1, and think medium clear.For AP2, AP1 is " concealed nodes ".Frame may be sent to its STA be associated by AP2 while AP1 transmits.But there is the STA be in the interference range of AP1 and AP2, lose at STA place due to conflict to make the transmission frame from AP1 and AP2.Such conflict is referred to as overlapping BSS and conflicts or conflict between BSS.
In a kind of prior art, describe time division multiple access (TDMA) method, wherein, each STA uses tdma slot (time period) to dispatch it and transmits.But it is synchronous that this mechanism requires between each STA, it regulates (scale) well along with STA quantity increases.In another prior art, conflict to solve between BBS, each access point uses beacon, dispatches its multicast and broadcast transmission in TDMA mode.It is synchronous that this method also requires between each BBS.
The method and apparatus conflicted between conflict and BBS in BSS that have step of not seeking common ground, that solve multicast transmission will be useful.The present invention solves both conflicts between conflict and BBS in BSS.
Summary of the invention
The present invention is directed to a kind of for transmitting reservation medium and the method for distribution medium subscription information for the multicast in WLAN (wireless local area network) and broadcast.Therefore, the collision probability that multicast and broadcast transmit is reduced, and transmission is protected.
Describe a kind of method and apparatus, it comprises: multicast Media reservation message, and receives the response for this medium reservation message.Also describe a kind of method and apparatus, it comprises: receiver media reservation message, determines that whether medium is idle, and transmits the response for medium reservation message in response to described determination.Further describe a kind of method and apparatus, it comprises: receiver media reservation message, determine whether the network allocation vector received in medium reservation message has the value being greater than current network allocation vector, determine whether to detect in the transmission of interim time on medium, and determine described current network allocation vector to reset in response to for the described of transmission.Further provide again a kind of method and apparatus, it comprises: receive the response for medium reservation message, determines whether the network allocation vector in described response is greater than current network allocation vector; And determine in response to described, upgrade described current network allocation vector.
In addition, invention further describes a kind of method and apparatus, it comprises: receive described message by the station of addressing non-in the message for reserved communication medium; Determine whether the network allocation vector received in described message has the value being greater than current network allocation vector; Determine whether to detect in the transmission of interim time on described communication media; And determine in response to for the described of transmission, described current network allocation vector is reset.
In addition, invention further describes a kind of method and apparatus, it comprises: receive the response for described message by the station of addressing non-in the message for reserved communication medium; Determine whether the network allocation vector in described response is greater than current network allocation vector; And determine in response to described, upgrade described current network allocation vector.
Accompanying drawing explanation
When being read by reference to the accompanying drawings, the present invention obtains best understanding according to following detailed description.Accompanying drawing comprises each figure of following concise and to the point description:
Fig. 1 is the schematic diagram at the station be associated with access point, and it illustrates the conflict in Basic Service Set.
Fig. 2 is the schematic diagram that the conflict relating to multiple Basic Service Set is shown.
Fig. 3 describes the example format of MB-RTS frame/message/signal.
Fig. 4 illustrates the example format of MB-CTS frame.
Fig. 5 A illustrates the example format of MB-NCTS frame.
Fig. 5 B illustrates the example format of CEL-MB-RTS frame.
Fig. 6 illustrates and is initiating multicast/broadcast STA and the operation received between multicast/broadcast STA and Frame switch sequence according to of the present invention.
Fig. 7 be in accordance with the principles of the present invention, initiate STA for transmitting for multicast/broadcast the flow chart of operation preengaging medium.
Fig. 8 A and 8B is in accordance with the principles of the present invention jointly, receives the flow chart of operation of STA in response to the multicast/broadcast from the MB-RTS initiating STA.The process of Fig. 8 B is optional.
Fig. 9 illustrates the example format of CEL-MB-CTS frame.
Figure 10 be receive MB-RTS frame/message/signal STA at this STA neither the promoter of MB-RTS message/signal/frame neither receiver/destination time the flow chart of operation.
The flow chart of operation when Figure 11 is the MB-RTS message/frame/signal of STA before this MB-CTS frame/message/signal is not addressed to this reception STA and this STA does not receive receiving MB-CTS signal/message/frame.
Figure 12 is the flow chart of the operation of STA when this STA is not the STA of this CEL-MB-CTS message/signal/frame institute addressing receiving CEL-MB-CTS frame/message/signal.
Figure 13 is the flow chart of the STA operation of the probability contention resolution scheme using distribution.
Figure 14 is the flow chart of the STA operation of the many bouts probability contention resolution scheme using distribution.
Figure 15 illustrates that CCP is to time slot and the segmentation in stage.
Figure 16 is the block diagram of exemplary of the present invention.
Embodiment
Based in the WLAN (wireless local area network) of IEEE802.11, the Carrier Sense Multiple with conflict avoidance is accessed (CSMA/CA) for access point (AP)/stand (STA)/equipment/receiver/mobile device/mobile radio station/mobile terminal so that access medium transmits.Below, unless otherwise defined, STA comprises AP.In CSMA, wish that first the STA carrying out transmitting intercepts wireless medium/channel, to check any activity on medium for measuring (interFrameGap/spacing adds the random-backoff time after busy medium situation) sometime.If medium is sensed to be " idle/unimpeded ", then STA is allowed to transmit.If medium is sensed to be " busy ", then STA must delay its transmission.In CSMA, multiple STA may transmit simultaneously, and this leads to a conflict.It should be noted that, as used herein, mobile device includes but not limited to dual-mode intelligent phone, computer, laptop computer, notebook computer, PDA(Personal Digital Assistant), or the wireless spectrum of any part or a part (radio wave) can be used to carry out any miscellaneous equipment communicated.
As shown in Figure 1, stand and to be associated with AP.AP forms Basic Service Set (BBS) together with its station be associated.Exemplarily, if AP and one or more STA that it is associated sends after sensing medium clear/unimpeded simultaneously, then frame/grouping that AP with STA sends conflicts mutually and loses.Such conflict appears in BSS, and is called conflict in BSS.The conflict of another kind of type illustrates in fig. 2.AP1 and AP2 to be operated in same channel/frequency and overlapping.Circular cross section represents the interference range of AP1 and AP2.Frame is sent to its STA(be associated such as by AP1, is sent to STAS4 or STAS1).AP2 can not the transmission of uppick AP1, and thinks that medium is idle.For AP2, AP1 is " concealed nodes ".Frame may be sent to its STA5 be associated by AP2 while AP1 carries out transmitting.Therefore, occur conflict at STAS1, S4 and S5 place, and STAS1, S4 and S5 can not correctly received frame/data.Such conflict between each BBS, and is referred to as between BSS and conflicts.
In order to reduce between multiple STA and among collision probability, by medium being preengage a time period, collision avoidance mechanism to be used for the clean culture in IEEE802.11WLAN before transmission actual data frame.It is also referred to as virtual carrier mechanism.When a STA wants to transmit to another STA, it senses carrier wave.Carrier sense comprises both physical carrier sensing and virtual carrier.Virtual carrier indicates other STA whether to be subscribed to medium.In carrier sense (physical carrier sensing and virtual carrier), once channel idle/unimpeded and permit that STA transmits, then initiation STA can by RTS(request-to-send) frame is sent to reception/destination STA.If medium is also idle at receiver place, then receiving STA with CTS(clear-to-send) frame replies.Only after receiving CTS, initiate STA and just start actual Frame transmission.If initiate STA do not receive CTS answer, then initiating STA can come repetition carrier sense and medium access process with back off time.RTS and CTS be swapped out present actual data frame transmit before.It is by informing that other STA all do not send on the radio medium in the period duration (specifying in the duration field of RTS and CTS frame) of reservation, thus is that ensuing data transmit reservation medium.By RTS or CTS frame, all STA be in the range of receiving of initiating STA or destination STA know that medium is preengage.Thus, even if the STA hidden can not receive RTS from initiation STA, from CTS, it also still can know that upcoming (impending) uses for the medium transmitting frame.For the above-mentioned example in Fig. 2, AP2 will know the medium reservation of AP1 in the CTS transmitted from STAS1, and can not transmit during the time period of AP1 reservation.
But in IEEE802.11WLAN, collision avoidance mechanism can not be used for broadcast and multicast.Reason is to there are the multiple destinations for RTS, and then responsively there are the multiple of CTS potentially and deposit transmitter.Therefore, these cts signals conflict at initiation STA place, and initiate STA and successfully can not receive CTS and start ensuing Frame transmission or Frame switch.In IEEE802.11WLAN, after carrier sense process, send multicast and broadcast frame immediately, and preengage without medium.In the present invention, multicast and broadcast collision avoidance mechanism is described.This mechanism reservation medium, and be broadcast and multicast transmission distribution medium subscription information.Broadcast is the special multicast at addressing (address) all stations.
The present invention can be described by following example.When STA(is as, AP) when wanting multicast or broadcast frame to be sent to multiple receiver/destination/equipment, it uses CSMA to perform carrier sense.Unless otherwise defined, carrier sense comprises physics and virtual carrier to guarantee that medium is idle sometime physically, and medium is not preengage by other STA.Successfully perform carrier sense once send/initiate STA and be ready for transmission, then it is before the actual multicast of transmission and broadcast frame, transmits the signal of such as control/management frames and so on to preengage medium.Here this signal is called MB-RTS(multicast/broadcastrequest-to-send).
MB-RTS frame/message/signal comprise frame control field, duration/id field, receiver address (RA) field, conveyer address (TA) field, the number of MB-CTS time slot, the number, FCS (FCS) field etc. of MB-NCTS time slot.As used herein, gap or time period when time slot is.Fig. 3 depicts the example format of MB-RTS frame/message/signal.Frame control field identification frames type, frame subtype and mark.Duration/id field provide initiate STA expect reservation medium time period.M AC (MAC) address of RA field instruction purpose receiver/destination.It is multicast or broadcast address.The MAC Address of TA field instruction conveyer/initiation STA.FCS field is received in the frame that device is used for determining to receive whether there is mistake.
Difference between MB-RTS and IEEE802.11RTS of the present invention is: MB-RTS field comprises the number of MB-CTS time slot and the number of MB-NCTS time slot.MB-CTS number field specifies MB-CTS to compete the period (CCP), that is, MB-RTS receiver be used for sending positive reply signal the time interval/number of time slot.As specified in the MB-CTS number of time slot field of MB-RTS, CCP is split into the transmission time slot of integer number.Each MB-CTS time slot represents the duration required for transmission positive reply signal.MB-NCTS number field specifies MB-NCTS negative competition period (NCCP), that is, MB-RTS receiver send that negative reply signal uses the time interval/number of time slot.As specified in the MB-NCTS number of time slot field of MB-RTS, NCCP is split into the transmission time slot of integer number.Each MB-NCTS time slot represents the duration for transmitting a negative reply signal.
After multicast/broadcast receiver/equipment receives MB-RTS, it determines that a MB-CTS time slot or a MB-NCTS time slot will be used respectively to send to be affirmed or negative reply.If multicast/broadcast receiver finds medium clear by physical carrier sensing and virtual carrier, then it can use a MB-CTS time slot to send positive reply signal, that is, for responding the control/management frames of MB-RTS for certain.Here, this positive reply is called MB-CTS(multicast/broadcastclear-to-send) frame.Whether virtual carrier determination medium has been preengage by another STA to delay to transmit.Channel open or free time mean that physical medium is idle and without any ongoing transmission, and do not have other STA to be subscribed to channel (that is, physical carrier sensing and the equal indicating channel/medium of virtual carrier are idle).MB-CTS frame/message/signal comprise frame control field, duration/id field, receiver address (RA) and FCS (FCS) etc.Frame control field identification frames type, frame subtype and mark.Duration/id field provides medium by the remaining time of preengaging.The MAC Address of RA field instruction purpose receiver/destination, it is the MAC Address of MB-RTS promoter.Fig. 4 shows the example format of MB-CTS frame.
If by physical carrier sensing and virtual carrier, multicast/broadcast receiver finds that medium is busy, then it can use a MB-NCTS time slot, sends negative reply signal/message, that is, for responding the control/management frames of MB-RTS in the negative.When physical carrier sensing or virtual carrier instruction busy medium, medium is considered to busy.Here, this negative reply signal is called MB-NCTS(multicast/broadcastnot-clear-to-send) frame.MB-NCTS frame comprise frame control field, duration/id field, receiver address (RA) and FCS (FCS) etc.Frame control field identification frames type, frame subtype and mark.Duration/id field provides medium by the remaining time or zero of preengaging.The MAC Address of RA field instruction purpose receiver/destination, it is the MAC Address of MB-RTS promoter.Fig. 5 A shows the example format of MB-NCTS frame.Even if when multicast/broadcast receiver finds that medium is busy by physical carrier sensing and virtual carrier, it also may not send MB-NCTS.The strategy that whether will send MB-NCTS can be configured on the basis of each STA.
The multicast/broadcast receiver intending to send MB-CTS selects MB-CTS time slot to transmit.In one embodiment, multicast/broadcast receiver can select a MB-CTS time slot among k MB-CTS time slot randomly, and wherein k is the value of the MB-CTS number of time slot field in the MB-RTS received.Intend to send the multicast/broadcast receiver of MB-NCTS by selection MB-NCTS time slot to send.In one embodiment, multicast/broadcast receiver can select a MB-NCTS time slot among m MB-NCTS time slot randomly, and wherein m is the value of the MB-NCTS number of time slot field in the MB-RTS received.Special situation is: in MB-RTS frame, and the value k of MB-CTS number of time slot and/or the value m of MB-NCTS number of time slot is 0, this means not allow multicast/broadcast receiver to send MB-CTS frame/message and/or MB-NCTS frame/message.Another special situation is: in MB-RTS frame, and the value k of MB-CTS number of time slot and/or the value m of MB-NCTS number of time slot is 1.This means that multicast/broadcast receiver only can send MB-CTS message/frame in one time slot, and/or send MB-NCTS message/frame in one time slot.
Multiple multicast/broadcast receiver is each can send MB-CTS message/frame and/or MB-NCTS message/frame in response to from the MB-RTS message/frame of initiating STA.If initiate STA the NCCP period (namely, time for MB-NCTS time slot) period do not receive signal (physical medium is idle), and the CCP period (namely, time for MB-CTS time slot) period receive at least one MB-CTS signal, then initiation STA can be used in its original MB-RTS and transmit imminent (pending) multicast/broadcast data or management frames for medium accesses the residue duration of the time of preengaging, or starts imminent Frame switch.Frame switch comprises initiates STA transmission multicast/broadcast frame/message/data and multicast/broadcast receiver transmission response (when there is any response, e.g., replying).Otherwise, initiate STA after back off time, repeat carrier sense and medium reservation routine.Note, MB-RTS initiates STA and can determine in a case where in MB-CTS time slot, have received MB-CTS signal/frame/message, described situation is: (1) is properly received MB-CTS frame/message/signal in MB-CTS time slot, or (2) during this MB-CTS time slot, correctly do not receive frame/message/signal, but transmission detected by wireless medium.A rear situation may appear at multiple STA use in response to MB-RTS frame/message identical MB-CTS time slot send MB-CTS frame/message/signal time.
In alternative embodiments, if initiate STA do not receive signal in period CCP period (time for MB-CTS time slot), or receive at least one MB-NCTS signal in period NCCP period (time for MB-NCTS time slot), then initiate STA and can send signal/control frame/management frames alternatively, with the MB-RTS frame/message transmitted before cancelling.Here, this signal is called CEL-MB-RTS(cancel-multicast/broadcast-request-to-send).CEL-MB-RTS frame/message/signal comprise frame control field, duration/id field, receiver address (RA) field, transmitter address (TA) field, FCS (FCS) field etc.Fig. 5 B shows the example format of CEL-MB-RTS frame.Frame control field identification frames type, frame subtype and mark.Duration/id field comprises medium by the remaining time of preengaging.The MAC Address (multicast) of RA field instruction purpose receiver/destination.The MAC Address of TA field instruction conveyer.FCS field is received device and is used for checking in the frame received whether there is mistake.Whether STA uses this alternative embodiment to be configured.The STA receiving CEL-MB-RTS when STA use from MB-RTS frame/message before information as nearest basis upgrade its NAV arrange, its network allocation vector (NAV) is reset.
Fig. 6 shows according to the operation between initiation multicast/broadcast STA of the present invention and reception multicast/broadcast STA and Frame switch sequence.Such as, for preengaging in the CSMA multicast/broadcast system of multicast/broadcast opportunity (MB-TXOP), AP is associated with three multicast/broadcast receivers.After AP successfully performs carrier sense, AP sends MB-RTS frame/message/signal to preengage medium.Then, multicast/broadcast receiver responds for multicast/broadcast receiver responds in the time slot distributed in MB-RTS message/frame.Multicast/broadcast receiver 1,2 and 3 eachly responds for certain by transmitting MB-CTS frame/message/signal.Multicast/broadcast receiver is not had to respond in the negative by transmitting MB-NCTS frame/message/signal.Do not receive MB-NCTS because AP receives at least one MB-CTS, therefore obtain MB-TXOP.AP transmits imminent Frame in preengage MB-TXOP.
Fig. 7 is for transmitting the flow chart of the operation of the initiation STA of reservation medium for multicast/broadcast according to the principle of the invention.At 702, AP, initialization is carried out to backoff counter.705, its execution physics and virtual carrier are to determine that whether medium is idle.708, test is performed to the result of carrier sense.If medium is not idle (medium is busy), then AP performs carrier sense again.If medium is idle, then 710, AP successively decrease/reduce/reduce its backoff counter.Test is performed 712.If backoff counter is non-vanishing, then AP performs carrier sense again.If backoff counter is zero, then determine medium subscription time at 715, AP, and construct/build MB-RTS frame/message/signal.Medium subscription time is the summation of the time of transmitting required for MB-RTS frame/message/signal, the summation of the time quantum (adding any interframe guard time) of the data that delivery time and transmission AP needs for MB-CTS and MB-NCTS number of time slot send.At 720, AP, MB-RTS frame/message/signal is sent to its receiver be associated.Arrange waiting timer at 725, AP to be responded by MB-CTS and/or MB-NCTS frame with the receiver waited for it and be associated.Continue to check waiting timer so that waiting timer expires at 730, AP.Once waiting timer is expired, then determine whether it has received any MB-NCTS frame at 735, AP.If AP has received any MB-NCTS frame, then it has proceeded to 702 to wait for back off time and again to perform carrier sense.If AP not yet receives any MB-NCTS frame, then determine whether it has received any MB-CTS frame at 740, AP.If AP not yet receives any MB-CTS frame, then it proceeds to 702 to wait for back off time and again to perform carrier sense.If the receiver that AP has been associated from it receives MB-CTS frame, then transmit multicast/broadcast frame at 745, AP and/or start the Frame switch of multicast/broadcast receiver associated with it.Determine that whether medium reservation is expired for turn-on time at 750, AP.If medium access subscription time is expired, then AP proceeds to 702 to wait for back off time and again to perform carrier sense.If medium access subscription time is not yet expired, then AP continues transmission multicast/broadcast frame and/or starts the Frame switch of receiver associated with it.
In an alternate embodiment, initiate STA and receive N number of signal during the NCCP period, and during the CCP period, receive C MB-CTS signal.If N<Nt and C>=Ct, then initiation STA can use in its original MB-RTS and transmit imminent multicast/broadcast data or management frames for medium accesses the residue duration of the time of preengaging, or starts imminent Frame switch.Nt and Ct is the parameter that can configure.
In another embodiment, initiate STA and receive N number of signal during the NCCP period, and during the CCP period, receive C MB-CTS signal, if N>=Nt or C<Ct, then initiate STA and can send signal/controls/management frames (CEL-MB-RTS) alternatively with the MB-RTS frame/message/signal of transmission before cancelling.
Fig. 8 A and 8B is the flow chart receiving the operation of STA in accordance with the principles of the present invention in response to the multicast/broadcast from the MB-RTS initiating STA jointly.The process of Fig. 8 B is optional.805, tested media is to determine whether it is idle.If medium clear, then determine whether to send MB-CTS message/signal/frame based on strategy and the MB-CTS number of time slot distributing/specify in the MB-RTS signal/frame/message received 810.If determine to send MB-CTS message/frame/signal, then 815, among the MB-CTS time slot distributing/specify from MB-RTS signal/frame/message, select a MB-CTS time slot.820, perform test to determine whether to have selected time slot.If not yet select time slot, then process terminates.If have selected MB-CTS time slot, then 825, MB-CTS message/frame/signal is sent/is sent to the initiation STA of MB-RTS.If medium is not idle/busy, then 830, determine whether to send MB-NCTS message/signal/frame based on strategy and the MB-NCTS number of time slot distributing/specify in the MB-RTS signal/frame/message received.If determine to send MB-NCTS message/frame/signal, then 835, among the MB-NCTS time slot distributing/specify from MB-RTS signal/frame/message, select a MB-NCTS time slot.840, perform test to determine whether to have selected time slot.If not yet select time slot, then process terminates.If have selected MB-NCTS time slot, then 845, MB-NCTS message/frame/signal is sent/is sent to the initiation STA of MB-RTS.
Fig. 8 B as implied above is optional.Namely, based on strategy or configuration, if STA determines that (namely the initiation STA of MB-RTS does not use medium after transmission MB-CTS message/frame/signal, if do not transmit frame via medium during the detection period), then can select whether send CEL-MB-CTS(cancellationmessage/frame/signal, cancel message/frame/signal).850, determine whether to send CEL-MB-CTS message/frame/signal.If determine to send CEL-MB-CTS message/frame/signal, then 855, arrange/start timer T1.860, test timer T1 and perform tight loop (tightloop), until timer T1 expires.Once timer T1 expires, then arrange 865 and detect timer T.870, perform test to determine whether exist during interval T/to have there is any transmission.If without any transmission during interval T, then perform test to determine that whether interval T is expired 875.If interval T is expired, then send/transmit CEL-MB-CTS message/frame/signal.If determine not send CEL-MB-CTS message/frame/signal, then process terminates.Transmit if existed during interval T, then process terminates.If timer T is not yet expired, then continue in 870 process.
The time period that is exchanged for of MB-RTS and MB-CTS frame preengages medium to transmit data and management frames/signal/message.MB-RTS, MB-CTS and MB-NCTS frame comprise duration/id field, it is specified for multicast/broadcast conveyer meeting (MB-TXOP) to preengage the time period of medium.MB-TXOP be specific STA have permission by/use wireless medium to start time interval of one or more frame transmission or Frame switch sequence.MB-TXOP was limited by time started and maximum duration.In MB-RTS frame duration/value of id field is set to initiate the residue duration that STA expects the MB-TXOP of reservation medium.It comprises send k MB-CTS frame, a m MB-NCTS frame and the time required for interframe guard time interval add the time of preengaging for transmitting imminent data, management frames and response frame (when there is the response frame of such as acknowledgement frame and so on).Duration value in MB-CTS and MB-NCTS is from the duration field immediately preceding MB-RTS frame before, deduct elapsed time and send this MB-CTS or MB-NCTS frame/message and the time required for interframe guard time interval and the value obtained.That is, the duration value in MB-CTS and MB-NCTS is set to the residue duration of MB-TXOP.In alternative embodiments, the duration value in MB-NCTS is set to zero.
The all STA be in the range of receiving of initiating STA know asked medium reservation by MB-RTS message/frame/signal.STA(is received namely when there is no multicast/broadcast, not by the STA of MB-RTS frame/signal/address messages) when receiving MB-RTS frame/signal/message, it is when new NAV value is greater than current NAV value, based on the MB-RTS frame received duration/id field in information upgrade its NAV and take/subscription time to indicate medium.NAV keeps the prediction (that is, virtual carrier situation) for the traffic in future on medium.When NAV being set to (non-zero), virtual carrier instruction is: medium is busy during the period that NAV is set up; When NAV not being set to (zero), instruction is this medium clear.Not as initiating a part of BSS of STA and the one or more MB-CTS frame/message/signal of the STA not receiving MB-RTS by being sent by the reception STA be associated with access point (STA), thus know that medium is preengage.Only when new NAV value is greater than current NAV value and be not only addressed in MB-CTS frame/signal/message and receive the STA that STA(is not the initiation STA of MB-RTS) and only before STA does not receive when MB-RTS, the STA receiving/intercept effective MB-CTS just based on MB-CTS frame duration/id field in the information that receives upgrade their NAV.Receive STA and may not receive MB-RTS frame/signal/message (such as, if it is outside the range of receiving of initiating STA), but receive the MB-CTS frame/signal/message receiving one of STA transmission from multicast/broadcast.MB-RTS/MB-CTS mechanism can improve operation when utilizing multiple BSS overlap of same channel/medium.It also can reduce conflict at following STA place: (namely described STA does not receive MB-RTS frame/message/signal from initiation STA, for MB-RTS promoter, they are concealed nodes), but still the imminent reservation (in the range of receiving of MB-CTS transmitter) of medium is learnt from MB-CTS frame/message/signal.Receive and will not ignore this MB-NCTS frame/signal/message to the STA of the MB-NCTS frame/signal/message of its addressing.
In alternative embodiments, when receive do not used to the STA of the MB-NCTS frame/signal/message of its addressing from MB-CTS frame/signal/message before or before the information of MB-RTS frame/signal/message arrange to upgrade its NAV as nearest basis, its NAV can reset by this STA.When this STA do not use from MB-CTS frame/signal/message before or before the information of MB-RTS frame/signal/message arrange to upgrade its NAV as nearest basis, this STA by described in ignoring not to the MB-NCTS of its addressing.Whether STA uses this alternate embodiment to be configured.
If time T1 start and at the time period T(T=T2-T1 that time T2 terminates) period do not detect physical layer transmission, then its NAV resets with the STA upgrading its NAV and arrange as basis recently by the information from MB-RTS frame/message/signal of permitting to use.T1 can be calculated as receive MB-RTS frame time+(# of MB-CTS time slot) * (MB-CTS_Time)+(# of MB-NCTS time slot) * (MB-NCTS_Time)+for all interframe protection interlude.T2 equals T1+wait_time.MB-CTS_Time is the time for sending MB-CTS frame/message/signal.MB-NCTS_Time is the time for sending MB-NCTS frame/signal/message.Wait_time is following parameter, and this parameter guarantees to there is not the transmission by wireless medium for waiting for.MB-CTS_Time and MB-NCTS_Time uses the size of MB-CTS/MB-NCTS frame/signal/message and the data transfer rate received according to this for the MB-RTS frame/message/signal of nearest NAV renewal calculates.
If start at time T1 and physical layer transmission do not detected during the above-mentioned time period T terminated at time T2, then can send signal/control frame/management frames alternatively with the MB-CTS transmitted before cancellation in response to the STA of MB-RTS transmission MB-CTS.Here, this signal/message/frame is called CEL-MB-CTS(cancel-multicast/broadcast-clear-to-send).CEL-MB-CTS frame comprise frame control field, duration/id field, receiver address (RA), FCS (FCS).Frame control field identification frames type, frame subtype and mark.Duration/id field provides medium by the remaining time or zero of preengaging.The MAC Address of RA field instruction purpose receiver/destination, it is the MAC Address of MB-RTS promoter.Fig. 9 illustrates the example format of CEL-MB-CTS frame.Whether to send optional CEL-MB-CTS frame can be configured on the benchmark of each STA.When the STA receiving CEL-MB-CTS has used the information from MB-CTS frame before to arrange to upgrade its NAV as nearest basis, its NAV has reset by this STA.
In alternative embodiments, when in response to MB-RTS send MB-CTS STA receive not to its addressing MB-NCTS after reset its NAV, this STA can send alternatively signal/control frame/management frames with cancel before transmit MB-CTS.
Figure 10 be receive MB-RTS frame/message/signal STA at this STA neither the promoter of MB-RTS message/signal/frame neither receiver/destination time the flow chart of operation.1005, perform test to determine whether the NAV value in MB-RTS message/signal/frame duration field is greater than the current NAV value stored of STA.If the new NAV value in MB-RTS message/signal/frame duration field is greater than the current NAV value stored of STA, then 1010, the current NAV had by STA is updated to the NAV value in the MB-RTS frame/signal/message received.If the new NAV value in MB-RTS message/signal/frame duration field is less than or equal to the current NAV value stored of STA, then process stopping.1015, timer T1 is set.1020, perform test to determine that whether timer T1 is expired.If timer T1 is not yet expired, then process is from continuing in tight loop, until timer T1 expires.Arrange 1025 and detect timer T.Test is performed to determine whether transmission to be detected on medium/channel during time interval T 1030.If carried during time interval T on medium/channel and transmission detected, then process stopping.If transmission do not detected during time interval T on medium/channel, then perform test to determine that whether timer T is expired 1035.If timer T does not expire, then continue in 1030 process.If timer T is expired, then NAV value is reset to utilize the MB-RTS that receives deduct/cut elapsed time upgrade before preceding value.
Figure 11 be the STA that receives MB-CTS signal/message/frame MB-CTS frame/message/signal be not addressed to receive STA and this STA do not receive before MB-RTS message/frame/signal time the flow chart of operation.1105, perform test to determine whether the new NAV value in the MB-CTS duration field that receives is greater than the current NAV value stored of STA.If the new NAV value in the MB-CTS message/frame/signal duration field received is greater than the current NAV value stored of STA, then 1110, the current NAV value had by STA is updated to the NAV value in the MB-CTS frame/signal/message received.If the new NAV value in the MB-CTS message/frame/signal duration field received is less than or equal to the current NAV value stored of STA, then process stopping.
Figure 12 is the flow chart of the operation of STA when this STA is not the STA of this CEL-MB-CTS message/signal/frame institute addressing receiving CEL-MB-CTS frame/message/signal.1205, perform test to determine whether STA has used information from MB-CTS frame/message/signal before as nearest basis to upgrade its NAV value.If STA has used information from MB-CTS frame/message/signal before as nearest basis to upgrade its NAV value, then STA its NAV value is reset to utilize MB-CTS deduct/cut elapsed time upgrade before preceding value.If STA does not use information from MB-CTS frame/message/signal before as nearest basis to upgrade its NAV value, then process stopping.
Alternate embodiment is described below, wherein, if multicast/broadcast receiver receives MB-RTS and by physical carrier sensing and virtual carrier determination medium clear, then multicast/broadcast receiver selects a MB-CTS time slot to send MB-CTS frame/signal/message.
MB-CTS competes the transmission time slot that the period (CCP) is split into integer number, specified by the # of the MB-CTS slot fields of MB-RTS frame/message/signal.Running probability contention resolved algorithm by transmitting at any one MB-CTS each the STA place transmitting MB-CTS signal/frame/message in time slot in hope, achieving the arbitration for medium access during CCP.
Each STA keeps degree of overlapping (OD), the number of the unique beacon that this degree of overlapping (OD) receives from different AP for this STA.What be associated with each OD is that MB-CTS transmits probability P T (OD).Success is received MB-RTS message/frame/signal and is at war with for transmission time slot in CCP by each STA of physics and virtual carrier determination medium clear.
In one case, scheme (in single bout) is run once.All STA select one and transmit time slot in CCP, and with probability P
t (OD)transmit MB-CTS frame/message/signal in this timeslot.Figure 13 is the flow chart of the STA operation of the probability contention resolution scheme using distribution.1305, calculate/calculate/determine OD.1310, perform test to determine whether STA receives MB-RTS message/frame/signal.If STA does not receive MB-RTS message/frame/signal, then process and continue in tight loop, until receive MB-RTS/ frame/signal/message.If STA receives MB-RTS message/frame/signal, then to transmit between the number that MB-CTS specified in slot fields transmits time slot in 0 and the MB-CTS of MB-RTS signal/frame/message at 1315, STA and select MB-CTS to transmit time slot.1320, timer T is set.Timer T is for waiting for that selected MB-CTS transmits time slot.1325, perform test to determine that whether timer T is expired.If timer T is not yet expired, then processes and continue in tight loop, until timer T expires.If timer T expires, then 1330, transmit MB-CTS frame/message/signal with probability P T (OD).
In another case, scheme (in multi-round) is run repeatedly, and its scope transmits the number of time slot from 0 to MB-CTS.In every bout, STA selects the number between current pass/time slot # and maximum bout/time slot #.The all STA not selecting current pass/time-gap number delay to transmit MB-CTS message/signal/frame.All STA of current pass/time-gap number are picked with probability (1-P
t (OD)) delay and in that time slot, do not transmit MB-CTS.During specific bout, do not carry out all STA(of transmitting because they do not select this bout #, or cause them to delay because their MB-CTS transmits probability and do not transmit in this bout) move on to be at war with in second leg.The all STA carrying out transmitting in specific bout that have a chance or opportunity avoid being at war with in further any/bout in the future.Figure 14 is the flow chart of the STA operation of the many bouts probability contention resolution scheme using distribution.1405, calculate/calculate/determine OD.1410, perform test to determine whether to receive MB-RTS signal/message/frame.If not yet receive MB-RTS message/signal/frame, then process and continue in tight loop, until receive MB-RTS message/signal/frame.If received MB-RTS signal/message/frame, then 1415, current pass/time-gap number is set to 0.MB-CTS is selected to transmit time slot 1420.MB-CTS transmits time slot and transmits between the number of the MB-CTS transmission time slot in slot fields at the MB-CTS of current pass/time-gap number and MB-RTS/ frame/signal/message.1425, timer T is set to wait for, until/startup appears/start in current time slots.1430, perform test to determine that whether timer T is expired.If timer T is not yet expired, then processes and continue in tight loop, until timer T expires.If timer T expires, then perform test to determine the time-gap number whether current pass number equals selected 1435.If current pass number equals selected time-gap number, then 1440, with probability P
t (OD)transmit MB-CTS frame/signal/message.1445, perform test to determine whether to transfer MB-CTS frame/signal/message in current time slots.If transfer MB-CTS frame/signal/message in current time slots, then process stopping.If do not transmit MB-CTS frame/signal/message in current time slots, then 1450, current pass number is increased progressively 1.1455, perform test to determine whether current pass number equals the number of the MB-CTS transmission time slot of specifying in the MB-CTS transmission slot fields of MB-RTS frame/message/signal.1420, process continues.If current pass number is not equal to selected time-gap number, then continue in 1450 process.
In order to optimize single and probability contention resolution strategy that is multi-round further, each transmission time slot in CCP is divided into two stage-signaling phase and response (ACK) stage.Signaling phase by STA for transmitting MB-CTS frame/signal/message, and acknowledgment phase by STA(, it at first transmits MB-RTS message/signal/frame) for sending MB-CTSACK.Figure 15 illustrates that CCP is to time slot and the segmentation in stage.OD equal 1 all STA(its during the acknowledgment phase at particular time-slot interval, listen to MB-CTSACK) suppress in slot time subsequently transmission.
When increasing order-assigned with OD and transmitting probability, the STA with higher OD is endowed higher prioritizing selection (preference).Which increase scope and the effect (potency) of MB-CTS frame/signal/message, more may be heard by the AP of multiple overlap as it.Identical scheme can be used for the competition solving MB-NCTS time slot between MB-NCTS conveyer.
For for wireless mesh network, wireless lan (wlan), self-organizing (adhoc) network or independently in Basic Service Set (IBSS) for multicast and broadcast transmit the station (STA comprises station and AP) of reservation medium and distribution medium subscription information, also can use the present invention.The present invention can be used for the p2p multicast between station.Such as in video conference or other p2p are served, the channel that can use method of the present invention to access for multi-case data being sent to other stations of standing.
In another embodiment, method of the present invention can use in the ip layer.If use method of the present invention on IP layer, then receiver/the destination-address in MB-RTS/MB-CTS/MB-NCTS/CEL-MB-RTS/CEL-MB-CTS message and conveyer/promoter/source address are IP addresses.
Referring now to Figure 16, it is the block diagram of exemplary of the present invention.Due to STA and/or AP(, it is special STA) can be conveyer, receiver or transceiver, therefore, employ the single block diagram that the wireless communication module with radio transmitter/receiver is shown.That is, radio transmitter/receiver can be conveyer, receiver or transceiver.The present invention includes host computing system and communication module (wireless).Host processing systems can be all-purpose computer or special-purpose computing system.Host computing system can comprise CPU (CPU), memory and I/O (I/O) interface.Wireless communication module can comprise MAC and baseband processor, radio transmitter/receiver and one or more antenna.Antenna transmission and receiving radio signals.Radio transmitter/receiver performs radio signal process.MAC and baseband processor perform MAC for transmission/reception and control and data framing (dataframing), modulating/demodulating, coding/decoding.At least one embodiment of the present invention may be embodied as in host computing system or wireless communication module for the treatment of data and the transmission of control signal and the routine of reception.That is, the block diagram of Figure 16 may be embodied as hardware, software, firmware, field programmable gate array (FPGA), application-specific integrated circuit (ASIC) (ASIC), risc (RSIC) or its any combination.Further, above-mentioned various flow chart and the exemplary process shown in text are operationally implemented among the combination of host processing systems or wireless communication module or host processing systems and communication module.This block diagram makes it possible to carry out various method/process thus completely in hardware, software, firmware, field programmable gate array (FPGA), application-specific integrated circuit (ASIC) (ASIC), risc (RSIC) or its any combination.
Should be appreciated that the present invention can hard disk in a variety of manners, software, firmware, implement in application specific processor or its combination.Preferably, be the combination of hardware and software by the invention process.In addition, by implement software be preferably the application program specialized on program storage device in tangible mode.This application program can be uploaded to the machine comprising any suitable framework, and is performed by this machine.Preferably, this machine is implemented on the computer platform of hardware with such as one or more CPU (CPU), random-access memory (ram) and (multiple) I/O (I/O) interface and so on.This computer platform also comprises operating system and microinstruction code.Various process described here and function can be the parts (or its combination) via the part of the microinstruction code performed by operating system or application program.In addition, other ancillary equipment various can be connected to computer platform, as additional data storage device and printing device.
It is also understood that, because some construction system assembly of describing in accompanying drawing and method step are preferably implemented with software, therefore, the actual connection between system component (or treatment step) may be different by the mode of layout according to the present invention.Consider in this instruction, those skilled in the art can conceive these and similar embodiment or configuration of the present invention.
Claims (12)
1. a medium reservation method, described medium reservation method comprises:
Receive described medium reservation message by the station of addressing non-in medium reservation message, described medium reservation message is used for reserved communication medium;
Determine whether the network allocation vector received in described medium reservation message has the value being greater than current network allocation vector;
If determine, the network allocation vector received in described medium reservation message has the value being greater than current network allocation vector, then determine whether to detect in the transmission of interim time on described communication media; And
The transmission during the described time interval on described communication media do not detected if determine, then described current network allocation vector is reset.
2. medium reservation method as claimed in claim 1, wherein, described communication media is wireless channel.
3. medium reservation method as claimed in claim 1, wherein, performs described medium reservation method via wireless network.
4. a medium reservation method, described medium reservation method comprises:
Receive the response for described medium reservation message by the station of addressing non-in medium reservation message, described medium reservation message is used for reserved communication medium;
Determine whether the network allocation vector in described response is greater than current network allocation vector; And
If determine, the network allocation vector in described response is greater than current network allocation vector, then upgrade described current network allocation vector.
5. medium reservation method as claimed in claim 4, comprises further:
Receive one and cancel message;
Determine whether to have updated described current network allocation vector in response to the described response that receives; And
Have updated described current network allocation vector if determine in response to the described response that receives, then described current network allocation vector is reset.
6. medium reservation method as claimed in claim 4, wherein, performs described medium reservation method via wireless network.
7. a medium device for displaying predetermined, comprises:
For being received the parts of described medium reservation message by the station of addressing non-in medium reservation message, described medium reservation message is used for reserved communication medium;
For determining whether the network allocation vector received in described medium reservation message has the parts of the value being greater than current network allocation vector;
When determining that the network allocation vector received in described medium reservation message has the value being greater than current network allocation vector, for determining whether the parts in the transmission of interim time on described communication media to be detected; And
When determining the transmission during the described time interval on described communication media not detected, for the parts that described current network allocation vector is carried out resetting.
8. medium device for displaying predetermined as claimed in claim 7, wherein, described communication media is wireless channel.
9. medium device for displaying predetermined as claimed in claim 7, wherein, described medium device for displaying predetermined communicates via wireless network.
10. a medium device for displaying predetermined, comprises:
For being received the parts of the response for described medium reservation message by the station of addressing non-in medium reservation message, described medium reservation message is used for reserved communication medium;
For determining whether the network allocation vector in described response is greater than the parts of current network allocation vector; And
When determining that the network allocation vector in described response is greater than current network allocation vector, for upgrading the parts of described current network allocation vector.
11. medium device for displaying predetermined as claimed in claim 10, comprise further:
For receiving the parts of a cancellation message;
For determining whether the parts that have updated described current network allocation vector in response to the described response that receives; And
When determining to have updated described current network allocation vector in response to the described response that receives, for the parts that described current network allocation vector is carried out resetting.
12. medium device for displaying predetermined as claimed in claim 10, wherein, described medium device for displaying predetermined communicates via wireless network.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310246764.4A CN103327640B (en) | 2008-06-18 | 2008-06-18 | The medium reservation method based on competition that in WLAN (wireless local area network), multicast transmits and device |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310246764.4A CN103327640B (en) | 2008-06-18 | 2008-06-18 | The medium reservation method based on competition that in WLAN (wireless local area network), multicast transmits and device |
| CN200880129930.XA CN102067634B (en) | 2008-06-18 | 2008-06-18 | Contention-based medium reservation method and apparatus for multicast transmissions in wireless local area networks |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN200880129930.XA Division CN102067634B (en) | 2008-06-18 | 2008-06-18 | Contention-based medium reservation method and apparatus for multicast transmissions in wireless local area networks |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103327640A CN103327640A (en) | 2013-09-25 |
| CN103327640B true CN103327640B (en) | 2015-12-23 |
Family
ID=49196089
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310246764.4A Active CN103327640B (en) | 2008-06-18 | 2008-06-18 | The medium reservation method based on competition that in WLAN (wireless local area network), multicast transmits and device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103327640B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2015106417A1 (en) | 2014-01-16 | 2015-07-23 | 华为技术有限公司 | Channel reservation method and communication device |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101035074A (en) * | 2007-02-16 | 2007-09-12 | 北京航空航天大学 | Non-confliction on-demand multi-address access method |
| CN101193416A (en) * | 2006-11-24 | 2008-06-04 | 大唐移动通信设备有限公司 | A random access method and base station and user terminal using this method |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2003105353A2 (en) * | 2002-06-11 | 2003-12-18 | Meshnetworks, Inc. | System and method for multicast media access using broadcast transmissions with multiple acknowledgments in an ad-hoc communications network |
| US7349349B2 (en) * | 2004-11-23 | 2008-03-25 | International Business Machines Corporation | Method and system for efficient and reliable MAC-layer multicast wireless transmissions |
-
2008
- 2008-06-18 CN CN201310246764.4A patent/CN103327640B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101193416A (en) * | 2006-11-24 | 2008-06-04 | 大唐移动通信设备有限公司 | A random access method and base station and user terminal using this method |
| CN101035074A (en) * | 2007-02-16 | 2007-09-12 | 北京航空航天大学 | Non-confliction on-demand multi-address access method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103327640A (en) | 2013-09-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102067651B (en) | Apparatus for multicast transmissions in wireless local area networks | |
| CN102067515B (en) | Collision mitigation for multicast transmission in wireless local area networks | |
| US11382067B2 (en) | Wireless communication method for simultaneous data transmission and reception and wireless communication apparatus using same | |
| US11737079B2 (en) | Wireless communication terminal and wireless communication method for transmitting uplink by multiple users | |
| US8737281B2 (en) | Apparatus for multicast transmissions in wireless local area networks | |
| AU2021323746B2 (en) | Channel contention method and related apparatus | |
| WO2015109599A1 (en) | Radio communication method, access point, and station | |
| JP2023540326A (en) | Channel access method and related equipment for multi-link devices | |
| US20230037601A1 (en) | Method and device for ultra-wideband communication | |
| CN103327640B (en) | The medium reservation method based on competition that in WLAN (wireless local area network), multicast transmits and device | |
| CN113825248A (en) | Channel access method of multilink equipment and related device | |
| US20220346148A1 (en) | Channel access method and related product | |
| CN116156434A (en) | Time domain cooperative data receiving and transmitting method, device, communication system, equipment and storage medium |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20190605 Address after: France Patentee after: Interactive Digital CE Patent Holding Company Address before: I Si Eli Murli Nor, France Patentee before: Thomson Licensing Corp. |