CN104135721B - The response of multicast data in wireless local area networks and the method and apparatus retransmitted - Google Patents

Abstract

The present invention describes a kind of method and apparatus, the described method includes：The multiple data cells of multicast；The request of reception of the multicast for the multiple data cell of response；Receive the signal in response to the request；Judge whether to receive the signal in response to the request from all receivers of the request for the first time；Based on received signal, the reception state of the multiple data cell is judged for the second time；The request for the multiple data cell of response is updated, any mark is removed to the response receiver received from it in response to the signal of the request for response；And the request of the multicast for response again.

Description

The response of multicast data in wireless local area networks and the method and apparatus retransmitted

The application be the applying date on 06 26th, 2008, it is Application No. 200880129876.9, entitled " wireless The divisional application of the application for a patent for invention of the response of multicast packet and the method and apparatus retransmitted in local area network ".

Technical field

Present invention relates in general to wireless communication, is replied in the wireless local area network in particular to one kind (acknowledge) and retransmit multicast packet method and apparatus.

Background technology

In this specification, "/" represents the other title of same or similar component or structure.That is, "/" can be understood as "or".Unicast (unicast) transmission be single transmitter (sender)/transmitter (transmitter) with single receiver it Between transmission.Broadcast (braodcast) transmission is single transmitter/transmitter and the whole in the range of receiving of the transmitter Transmission between receiver.Multicast (multicast) transmission is the range of receiving of single transmitter/transmitter and the transmitter Transmission between the subset of interior receiver, wherein the subset can receive all receivers of data transfer.That is, Herein referred multicast includes broadcast, therefore more broadly.Data are transmitted with being grouped (packet) or frame (frame).

In the wireless local area network, access point (AP)/base station/station (STA)/movement equipment/mobile terminal/node is in its profit Determine wireless medium/channel for sky with the physics with random back (random backoff) time and virtual carrier sensing in wireless network communication Transport multicast and broadcast frame immediately after not busy/unimpeded.Therefore, as multiple STA while attempt to will be clashed when transmitting.Example Such as, access point and its association STA are possible to be carried out at the same time transmission, then the frame all transmitted is lost due to conflict.For example, work as AP During to its several association STA multicast data transmission frame, STA in addition may transmit data or control frame to the AP.AP and its phase Connection STA is known as Basic Service Set (basic service set/BBS).The conflict occurred in BBS is known as conflict in BBS.Another In one example, AP1 and AP2 is operated in same channel/frequency and two BBS are overlapping.AP1 associates STA transmission to it Data frame.But AP2 cannot listen to the transmission of AP1 and think that medium is idle.AP1 is " hidden station " for AP2.AP2 When AP1 is transmitted STA transmission frames can be associated to it.But some STA are likely to be present in the interference range of AP1 and AP2, Therefore lost from the AP1 and AP2 frames transmitted in these STA due to conflict.Such conflict be known as overlapping BBS conflict or Conflict between BBS.

Multicast and broadcast provide the effective ways to multiple receivers distribution data.But in multicast and broadcast really The reliable data reception for protecting multiple receivers faces the challenge.It is of special importance that to provide a kind of effective mechanism carrys out response (acknowledge) multiple packets are received by multiple receivers in media access control layer and link layer.

High-rise (application layer and transport layer) scheme is proposed to improve multicast reliability.One existing scheme illustrates one kind Negative response (NACK) method, wherein will be sent out when receiver detects the missing of the packet sequence number received to transmitter Send NACK.This mode result in extra delay and be required for buffer in transmitters and receivers.Although by restraining by more The NACK quantity that a multicast receiver is sent can reduce feedback overhead, but such scheme is added for ensureing that high multicast can By property or the complexity without packet loss.

Patent application US2006/0109859 A1 " the METHOD AND SYSTEM FOR of the inventors such as Acharya EFFICIENT AND RELIABLE MAC-LAYER MULTICAST IN WIRELESS TRANSMISSIONS " illustrate to use Medium access control (MAC) layer method of reliable multicast in wireless network.Transmitter node sends to receiver node and asks Send (RTS) signal.The RTS signals include the group identifier or bit vector corresponding to the receiver node.Institute's rheme to Each instruction receiver node in amount.Receiver node is according to a group identifier or the ranking functions of bit vector (order function) sends clear to send (CTS) signal.Transmitter is receiving the rear to reception of at least one cts signal Device node sends packet.If packet is correctly received, one or more receiver nodes are according to the one of RTS signals Group identifier or the ranking functions of bit vector send one or more ack signals.This method uses 4-Way Handshake (four-way Handshake) with transmission and the single packet of response.The order for the ack signal that multiple receivers are sent is based in RTS signals Identifier or bit vector.Ack signal response single packet.The program can cause high expense and therefore reduction network throughput Amount.

In addition, in Wireless LAN (WLAN), access point may have a large amount of associated stations, or transmitter node tool There are a large amount of adjacent nodes.If RTS signals include the group identifier or bit vector corresponding to receiver node, RTS signals can It can become very big, this will cause more expenses.

Another method sends multicast packet in the wireless network using multiple unicasts.Access point unicast multicast number repeatedly According to packet, each unicast is exclusively used in simple target receiver, because unicast provides the MAC layer response and again in wireless network environment Pass.But this method needs that identical multi-case data is transmitted several times on common broadcast channel, which results in high expense and low net Network handling capacity.

2008/020731 A1 of patent application WO " the MULTICAST PROCEDURE IN A of the inventors such as Huh WIRELESS NETWORK " describe a kind of method, and wherein originator/access point is divided with multicast to multiple receivers transmission data Group and the reception state using unicast to the multicast data packet of each receiver difference poll precedent transmission.Because originator with Unicast asks (block acknowledgement request/BAR) message respectively please to each receiver transmission block response Reception state is sought, BAR message is transmitted several times in it, and each BAR message is used for a receiver.That is, originator with unicast with it is each (B-ACK) message is replied in receiver difference swap block response request (BAR) message and response, and each message is used for a reception Device.Therefore, this method still results in unnecessary expense and reduces network efficiency and handling capacity.

A kind of method and apparatus are needed, in multiple multicasts that the multiple receivers of MAC layer response of wireless network environment are sent Packet.Need a kind of to be used for data transfer, response and the reliable method of re-transmission.

The content of the invention

The present invention provides a kind of method and device, the multiple data cell/frame/packets sent for obtaining multiple receivers Reception state, for carrying out reliable multicast in a communication network.The described method includes：From transmitter node to receiver node Multiple data cell/frame/the packets of multicast, then please from the transmitter node to the receiver node multicast multicast block response Seek (M-BlockAckReq) signal.M-BlockAckReq signals are included on acknowledgment strategy and the multiple packets for needing response Information and a group identifier or the bitmap control with partial virtual bitmap (virtual bitmap).Using bitmap control and Partial virtual bitmap can reduce expense.Position in each identifier or bitmap corresponds to receiver node.In response to by one group Identifier or the multicast block response request M-BlockAckReq of bitmap instruction, receiver node send multicast block response (M- BlockAck) signal.The M-BlockAck signals that receiver is sent include multiple data of request-reply in M-BlockAckReq The receiving status information of unit/frame/packet.

The present invention describes a kind of method and apparatus, including：The multiple data cells of multicast and multicast are used for more described in response The request of the reception of a data cell；And receive signal in response to the request.Invention further describes a kind of method and apparatus, Including：Receive the multicast request that reply data receives；Judge whether to need to respond the request；Judge the data State；It is ready to respond to based on above-mentioned judging result and transmits the response.

The present invention describes a kind of method, it includes：The multiple data cells of multicast；Multicast is for the multiple data of response The request of the reception of unit；Receive the signal in response to the request；Judge whether for the first time from all of the request Receiver receives the signal in response to the request；Based on received signal, the multiple number is judged for the second time According to the reception state of unit；The request for the multiple data cell of response is updated, to having received from it response Any mark is removed in the response receiver of the signal of the request for response；And institute of the multicast for response again State request.

The present invention describes a kind of device, it includes：Wireless communication module for the multiple data cells of multicast；The nothing The request of reception of the line communication module also multicast for the multiple data cell of response；The wireless communication module receives response In the signal of the request；The wireless communication module judges whether to receive from all receivers of the request for the first time To the signal in response to the request；The wireless communication module is judged the multiple for the second time based on received signal The reception state of data cell；The wireless communication module updates the request for the multiple data cell of response, right Receive from it removing any mark in response to the response receiver of the signal of the request for response；And The request of the multicast for response again.

Brief description of the drawings

It is considered in conjunction with the accompanying following detailed description and is easier to understand the present invention.The brief description of accompanying drawing is as follows：

Fig. 1 shows example WLAN network；

Fig. 2 shows the wireless mesh network for including multiple station/nodes；

Fig. 3 shows utilization multicast block response request (M- according to an illustrative embodiment of the invention BlockAckReq) and multicast block response (M-BlockAck) carry out reliable multicast transport sequential；

Fig. 4 A show exemplary M-BlockAckReq signals/message/frame；

Fig. 4 B show the example format of the receiver information field in M-BlockAckReq signals/message/frame；

Fig. 5 A show exemplary M-BlockAck signals/message/frame；

Fig. 5 B show the example format of the BA control fields in exemplary M-BlockAck signals/message/frame；

Fig. 5 C show the example format of the BA information fields in exemplary M-BlockAck signals/message/frame；

Fig. 6 is the flow chart of multicast transmission process according to an illustrative embodiment of the invention；

Fig. 7 is the flow chart of multicast reception process according to an illustrative embodiment of the invention；

Fig. 8 is the control of utilization BAR receivers bitmap and BAR receivers part according to an illustrative embodiment of the invention The example format of receiver information field in M-BlockAckReq signals/message/frame of virtual bitmap；

Fig. 9 A show the multicast block being used to utilize with delay policy and response of another embodiment according to the present invention The sequential of (M-BlockAckReq) and the reliable multicast transport of multicast block response (M-BlockAck) exchange is asked in response；

Fig. 9 B show that the utilization that is used for of another embodiment according to the present invention has delay policy and unresponsive multicast The sequential of (M-BlockAckReq) and the reliable multicast transport of multicast block response (M-BlockAck) exchange is asked in block response；

Fig. 9 C show that the multicast block response for utilizing with multichannel poll of another embodiment according to the present invention please Seek the sequential of (M-BlockAckReq) and the reliable multicast transport of multicast block response (M-BlockAck) exchange；

Figure 10 is the block diagram of the exemplary realization of the present invention.

Embodiment

Embodiments of the present invention are illustrated using IEEE802.11 Wireless LAN (WLAN).But this hair It is bright to can be also used for other wireless and cable networks.The present invention can be used for medium access control (MAC)/link layer or higher (application layer and transport layer).

In the existing Wireless LAN based on IEEE802.11, multicast and broadcast are insecure.Do not have in MAC layer There are the response and re-transmission of multicast packet/packet/frame.Multicast in Wireless LAN based on IEEE802.11 is assisted by high-rise View recovers the multicastapackets lost, and which results in higher delay and relatively low network throughput.

Fig. 1 shows example WLAN network.The network includes access point (AP) and multiple stations (STA).AP is to multiple stations Send multicast and broadcast data/packet/frame.It is the special station for being connected to cable network to please note AP.Hereinafter, except non-specifically Point out, STA includes AP.Fig. 2 shows the wireless mesh network for including multiple station/nodes.Transmitter/transmitter is to multiple receptions Device/point of destination sends multicast and broadcast data/packet/frame.

If multiple stations try concurrently to access medium/channel to send/and transmit data in the network of share medium is used It may then clash.Channel access control mechanism is provided and causes multiple nodes using medium access control (MAC) technology It can communicate in a network.Csma (CSMA) is a kind of MAC technologies.In CSMA, it is desirable to be transmitted STA first carries out wireless medium/channel detecing for some time quantum (interframe space adding the back off time after medium busy condition) Listen, so as to check any activity on medium.It is transmitted if medium is listened for " idle/unimpeded ", permission STA.Such as Fruit medium is listened as " busy ", then STA must postpone its transmission.This is CSMA/ conflict avoidances (CSMA/CA) CA and CSMA/ punching The fundamental of prominent detection (CSMA/CD).Collision detection is used for by terminating transmission at once when detection falls and conflicts and reducing by the The secondary possibility for retrying conflict and improve the performance of CSMA.

CSMA/CA further include by send signal reservations (reserve) medium for a period of time (transmission opportunity) and to pure The modification of CSMA.In CSMA/CA, stand and carry out csma.The carrier sense include Physical carrier sense and Virtual carrier sensing in wireless network communication.Virtual carrier, which is intercepted, indicates whether other STA have reserved the medium.Once pass through physics and virtual load Ripple, which is monitored, determines that channel idle/unimpeded and STA is allowed to transmit, then dispatching station (originating station) can be sent out Request is sent to send (RTS) frame/message/signal.Target receiver (intended receiver) is if also listen to medium clear With regard to replying clear to send (CTS) frame/message/signal.RTS and CTS frames/message/signal, which exchanges, to be occurred to pass in actual data frame Before defeated, its reserved period that do not specified by informing/suggesting every other STA in RTS and CTS frames/message/signal passes through Share/share medium is transmitted and is that following data transfer reserves medium.The range of receiving of transmitter, receiver or both Interior whole STA learn medium predetermined case by RTS or CTS frames/message/signal and are protected during carrying out reserved station and transmitting Hold silence.CSMA/CA is used in the Wireless LAN based on IEEE802.11.

Another common media access control method for being used for share medium (such as wireless channel) network is the time-division Multiple access (TDMA).TDMA allows the shared same channel in multiple stations by the way that medium/channel is divided into different time-gap.To be each Node distributes the time slot for being used for transmission data.The scheduling that time slot utilizes be controlled by the central controller of access point/base station and Distribute (central schedule), or established in a distributed manner by node itself.

Poll is the media access control method for being used for shared channel for another.Access point or central controller control Make the medium access.AP can carry out downlink transfer (from AP to association STA) or AP using channel to associate STA with poll For uplink (from association STA to AP).

Multichannel poll (MP) is the media access control method for being used for shared channel for another.AP or controller can With sending time table (time schedule), AP and one or more STA use above-mentioned time table access wireless medium with into Row one or more downlink transfer and one or more uplink.

Fig. 3 shows utilization multicast block response request (M- according to an illustrative embodiment of the invention BlockAckReq) and subsequent multicast block response (M-BlockAck) carry out reliable multicast transport sequential.Transmitter/AP/ sources Device is sent out to multiple receiver/STA (such as receiver 1 and 2, but do not include receiver 3) multicast data transmission unit/packet/frame Block.Each data cell/packet/frame includes sequence number or frame identifier.The sequence number is incremented by 1 every time.Utilize CDMA, TDMA, wheel Ask or multichannel poll is transmitted.After it have sent the block of multicast packet, transmitter is to multicast receiver transport multicast BlockAckReq (M-BlockAckReq) signal.M-BlockAckReq signals include block ACK requests (BAR) control field, block ACK asks (BAR) information field and reliable multicast receiver (RMR) information field.BAR control fields and BAR information field bags Include the flow identifier symbol (TID) and block ACK start sequence numbers of multicast BlockAck (M-BlockAck) frame request.The start sequence number It is the sequence number of the first frame of M-BlockAckReq requests M-BlockAck.The reliable multicast receiver information field includes hair Go out the receiver identifier list of the block Ack requests of M-BlockAck.In figure 3, the identifier is to be used for receiver 1 and 2 Identifier.The identifier can be the station MAC Address, association ID or IP address (if the present invention IP layer execution/ Operating).Selectively, the reliable multicast receiver information field includes Bitmap Control field and bitmap field to send M- The receiver of BlockAck requests.The receiving station of each instruction request block Ack in bitmap.BlockAckReq requests connect Each receiver/the receiving station (being in the example of fig. 3 receiver 1 and receiver 2) received in device identifier list or bitmap presses Responded according to the receiver order/order determined in the list or bitmap with M-BlockAckReq.Receiver sends the M- BlockAckReq with response its with M-BlockAckReq signals/message/frame determine beginning sequence number data cell/point The reception state of group/frame block.According to M-BlockAckReq multicast receivers information field, (i.e. BlockAckReq is asked receiver Identifier list or bitmap) in determine same sequence/order send its M-BlockAck signals/message/frame.It may be selected Ground, receiver is according to as the sequence of receiver identifier in BlockAckReq identifier lists or BlockAckReq bitmaps The order of function sends its M-BlockAck signal.It is not included in the receiver list of the BlockAck requests of BlockAckReq Or receiver/STA in bitmap does not reply this BlockAckReq.In the embodiment shown in fig. 3, receiver 3 does not send M- BlockAck is with this M-BlockAckReq of response, because it is not included in the receiver identifier list of this BlockAck requests Or in bitmap.

Fig. 4 A show exemplary M-BlockAckReq signals/message/frame, it includes frame control field, period/ID words Section, receiver address (RA) field, emitter address (TA) field, BAR control fields, BAR information fields, receiver information (RI) field, Frame Check Sequence (FCS) field etc..Frame control field indicates frame type, frame subtype and mark (flag).Phase Between/id field indicates the remaining time that medium will be used for transmission.RA fields indicate Jie of target receiver/destination/receiving station Matter access control (MAC) address.MAC Address is multicast address.TA fields indicate the MAC Address of transmitter.BAR control fields and BAR information fields indicate task identifier (traffic identifier/TID) and ask this M- of M-BlockAck The starting frame number of BlockAckReq.Furthermore, it is possible to multiple classs of service (traffic category) or Business Stream (traffic stream) is with identical transmitter and receiver address but with different business identifier (TID).For example, have Video traffic can be used for a TID, and another TID is used for webpage data services.BAR control fields can also include block ACK strategies and M-BlockAckReq format indicators.For example, BAR control fields may define whether to need to this M- BlockAckReq carries out immediate answer, if can be to multiple class of service/business with different business identifier (TID) Stream carries out response together.For multiple TID in M-BlockAckReq, BAR information fields include TID and block response start sequence number Multiple collection, each TID has a start sequence number.TID_ for the BAR control fields of more TID M-BlockAckReq INFO subfields include the quantity of collection/routine of TID and BlockAck start sequence numbers.Receiver is sentenced using the FCS fields Whether there is mistake in disconnected receiving frame.Fig. 4 B show the receiver information field in M-BlockAckReq signals/message/frame Example format, it includes type/flags subfield and destination/receiver/receiving station's identifier list.Type/mark Field indicates the form of receiver information field.Destination/receiver/reception station identifier indicates that M-BlockAckReq is asked The STA/ receivers of answer.The identifier can be station MAC Address or association ID or IP address (if IP layer execution/ The operation present invention).

Fig. 5 A show exemplary M-BlockAck signals/message/frame, it include frame control field, period/id field, Receiver address (RA) field, emitter address (TA) field, BA control fields, BA information fields, Frame Check Sequence (FCS) word Section etc..Frame control field indicates frame type, frame subtype and mark (flag).Period/id field indicates that medium will be used for transmission Remaining time.RA fields indicate medium access control (MAC) address of target receiver/destination/receiving station, which is Ask the address of the M-BlockAckReq originator of this M-BlockAck.TA fields are the addresses at the station for transmitting this frame.BA is controlled Field and BA information fields indicate task identifier (TID), block ACK starting frame numbers and the number for M-BlockAck frame responses According to the block ACK bit figure of block/unit of/packet/frame.In addition, BA control fields can also include block ACK strategies and M-BlockAck Format indicator.The receiver judges whether there is mistake in receiving frame using FCS fields.

Fig. 5 B show the example format of the BA control fields in exemplary M-BlockAck signals/message/frame, it is wrapped Include mark and TID_Info subfields.The mark indicates block ACK strategies and M-BlockAck forms, for example whether needing to carry out Immediate answer, if response can be carried out together to multiple class of service/Business Streams with different business identifier (TID). TID_Info subfields include the TID that this M-BlockAck is response.Fig. 5 C show exemplary M-BlockAck signals/disappear The example format of BA information fields in breath/frame, it includes block ACK start sequence numbers and block ACK bit figure.The start sequence number is This M-BlockAck is the sequence number of the first data cell/packet/frame of response, itself and the previous M- just received The start sequence number of BlockAck signals/frame/message has identical value.Position position (bit position) n of BlockAck is corresponded to It is equal to the packet of (BlockAck Starting Sequence Control+n) in sequence number value.It is used to indicate multiple points The reception state of group/frame.This is arranged to the successful reception of 1 acknowledgment packet in BlockAck bitmaps.If BlockAck The position position n of figure is set as 1, point of its response sequence number value equal to (BlockAck Starting Sequence Control+n) The successful reception of group.If the position position n of BlockAck bitmaps is set as 0, its response sequence number value is equal to (BlockAck Starting Sequence Control+n) packet be not received.Have in addition, M-BlockAck signals can reply The multiple Business Streams or class of service of different TID.For multiple TID in M-BlockAck, BA information fields include multiple TID Collection/routine, block ACK start sequence numbers and M-BlockAck bitmaps, are each used for a TID.For more TID M-BlockAck's The TID_Info subfields of BA control fields include the quantity of collection/routine of TID infro, BlockAck start sequence numbers and BlockAck bitmaps.

M-BlockAckReq and M-BlockAck be possible to lose or not by target receiver/destination/receiving station just Really receive.If the transmission of multicast transmitter has the M- of receiver identifier list in receiver information field BlockAckReq and its fail to be properly received M-BlockAck signals, then the multicast transmitter from target complete receiver Retransmit the remaining receiver mark having in receiver information field since it receives the M-BlockAck signals not successfully Know the M-BlockAckReq of symbol list.Intended recipient in the remaining receiver identifier list of M-BlockAckReq Each of device/destination/receiving station response M-BlockAck.The above process is performed repeatedly, until M-BlockAckReq transmitters From target complete receiver/destination/receiving station receives M-BlockAck or number of retransmissions reaches capacity.It can also use Other strategies retransmit M-BlockAckReq and M-BlockAck.If for example, in M-BlockAckReq request-reply data Packet reaches its service life/validity limit, and multicast transmitter stops retransmitting M-BlockAckReq or sending rising with new block ACK The M-BlockAckReq of the renewal of beginning sequence number.Selectively, if M-BlockAckReq reaches its lifetime limitation, multicast is sent Device stops retransmitting M-BlockAckReq.According to another optional strategy, M-BlockAckReq transmitters are (pre- from some at it It is fixed) target receiver/destination/receiving station of part when receiving the M-BlockAck corresponding to this M-BlockAckReq or Person can stop retransmitting after the retrying of predetermined quantity.It is described to be partially larger than or equal to predetermined threshold.These strategies can be with Used individually or jointly.

After completing M-BlockAckReq and M-BlockAck and exchanging, multicast transmitter is by M-BlockAck bitmaps The information of offer judges whether to need to retransmit packet.(do not connect if lost according to receiver block ACK by one or more targets Device/destination/receiving station is received to be properly received) one or more packets, multicast transmitter arranges this or these lost packets Retransmit.The packet multicast of re-transmission is sent to target receiver/destination/receiving station.Retransmit lose packet and/or After transmission of new packets, multicast transmitter can send new M-BlockAckReq and be transmitted the reception shape of (re-transmission) packet State.If do not connect correctly by one or more target multicast receivers according to the bitmap one or more packets of receiver block response Receive, multicast transmitter arranges the re-transmission of this or these lost packets again.Perform this retransmission processes repeatedly for lost packets, Until the target complete receiver for sending M-BlockAck is properly received packet or the transmission service life (validity) of this packet arrives Phase.It note that other strategies that can also be used for data packet multicast.If for example, have correctly received packet Part receiver be greater than or equal to a threshold value, multicast transmitter stops retransmitting this packet.In another exemplary policy, such as The number of retransmissions of fruit packet, which reaches, retries the limit/threshold value, and multicast transmitter stops retransmitting this packet.These exemplary policies Can be used individually or jointly.

Fig. 6 is the flow chart of multicast transmission process according to an illustrative embodiment of the invention.To be more in step 605 A data cell/packet/frame multicast to target receiver.M-BlockAckReq counters are initialized in step 610 and in step 615 carry out multicast.Increase M-BlockAckReq counters in step 620 and/initialization timer is set in step 625.In step The station of data described in rapid 630 transmission/multicast starts to receive M-BlockAck.Test in step 635 to judge whether time-out (in the timer expiration that step 625 is initialized/set).If had not timed out, process return to step 630.If it times out, Step 640 is tested to judge whether to receive M-BlockAck from all target receiver/destination/receiving stations.If M-BlockAck is received from all target receiver/destination/receiving stations, then process continues from step 650.If not from institute There is target receiver/destination/receiving station to receive M-BlockAck, then test in step 645 to judge M- Whether BlockAckReq counters more than M-BlockAckReq retry the limit/threshold value.Can also be according to above-mentioned other strategy The judgement is carried out, such as judges that the M-BlockAckReq quantity of reception and the ratio of desired M-BlockAckReq quantity are It is no to exceed threshold value.If M-BlockAckReq counters retry the limit/threshold value more than M-BlockAckReq, in step 650 M-BlockAck is examined to judge the data mode of multicast/transmission.Test in step 655 to judge whether each multicast point Group (multicast packet) have answered M-BlockAck target receiver receive or the transmission service life of packet/data (effectively Property) whether be exceeded (expired).If the target receiver that multicastapackets (multicast packet) not have answered M-BlockAck connects Receive or if the transmission service life (validity) of packet/data be not exceeded (expired), in step 660 transmitter/transmitting Device arrangement is broadcast to target receiver/destination/receiving station's re-transmission/restructuring does not receive/dont answer packet.Examined in step 665 Test so that whether the state for judging total data/packet of requested state has all verified and updated.If requested state is complete The state of portion's data/packet is not all verified and updates, then process return to step 650.If whole numbers of requested state According to the state of/packet is all verified and renewal, then process return to step 605.If multicastapackets (multicast packet) are by response The target receiver of M-BlockAck receive or if transmission service lifes (validity) of packet/data be not exceeded the (phase It is full), then process continues in step 665.If M-BlockAckReq counters retry the limit/threshold not less than M-BlockAckReq Value, then step 670 update M-BlockAckReq and M-BlockAckReq will be carried out receiver/destination of response/ Receiving station removes from the blockack request lists in M-BlockAckReq.Then process continues in step 615.

Fig. 7 is the flow chart of multicast reception process according to an illustrative embodiment of the invention.Received in step 705 Device/destination/receiving station receives M-BlockAckReq.Test in step 710 to judge that this receiver/destination/connects Receive whether station is target receiver (receiver for sending blockack replies/response request to M-BlockAckReq).If This receiver/destination/receiving station is not that (the blockack replies/response sent to M-BlockAckReq please for target receiver The receiver asked), then process terminates.If this receiver/destination/receiving station is that target receiver (is sent to M- The receiver of the blockack replies of BlockAckReq/response request), then step 715 determine this receiver receive and The state of the multicast packet/packet of (in M-BlockAckReq) request-reply and preparation/generation M-BlockAck signals/frame/ Message.The M- that the order determined in step 720 according to the information for being provided/being set by M-BlockAckReq/order transmission prepares BlockAck。

In another embodiment, the receiver information field in M-BlockAckReq signals includes the sub- word of type/mark Section, BAR receiver bitmaps Control Subfield, BAR receiver partial virtuals bitmap (partial virtual bitmap) etc..Figure 8 be according to an illustrative embodiment of the invention utilize BAR receivers bitmap control and BAR receiver partial virtual bitmaps The example format of receiver information field in M-BlockAckReq signals/message/frame.BAR receiver Bitmap Control fields For single eight-bit group (octet).Seven (position 1-7) of field forms Bitmap Offset (bitmap offset).One position (position 0) Retain.The length of partial virtual bitmap is change and is multiple eight-bit group, this can be determined from total frame sign.Bitmap is inclined Moving sub-field value has the association ID (AID) divided by 16 at station.If the value is N, stations of the AID less than 16xN is not included in M- In the list at the station of this M-BlockAckReq of BlockAck responses.Each in partial virtual bitmap field is corresponding to specific Stand.Bit number i (0≤I≤2007) in bitmap field, i.e. eight-digit number in bitmap fieldBit number (i mod8) every When the low order position of a eight-bit group is bit number 0 and high order position is bit number 7, corresponding to the station that AID is 16xN+i.If position Position i in figure field is arranged to 1, then the erect-position that AID is 16xN+i please in the requested answer for replying this M-BlockAckReq Ask in the list of station, wherein N is Bitmap Offset Field value.If the length of partial virtual bitmap field is L eight-bit group, AID Station more than or equal to 16xN+8xL is not in answer request station list.Target receiver/destination/receiving station is according to wherein Same sequence/order of receiver is specified to send its M-BlockAck signal in the BAR receiver bitmaps of M-BlockAckReq. Selectively, target receiver/destination/receiving station is according to according to specifying in M-BlockAckReq BAR receiver bitmaps The definite order of receiver order sends its M-BlockAck signal.

For example, the value of Bitmap Control field is 50.The size of part virtual bit figure is 2 eight positions in M-BlockAckReq Group.Bitmap is 10,111,111 01111111.Whole stations of the AID less than 16x50=800 do not send M-BlockAck, because these Stand without write-in M-BlockAckReq.Stations of the AID more than or equal to 800+2x8=816 does not also send M-BlockAck.M- The i-th position instruction AID is the station of 800+i in the Partial Bitmap of BlockAckReq.Based on bit format (bit pattern) 10111111 01111111, AID are equal to 800,802,803,804,805,806,807,809,810,811,812,813,814 M-BlockAck will be sent in sequence with 815, because its corresponding positions is arranged to 1.Stations of the AID equal to 801 and 808 will not be sent out M-BlockAck is sent, because its corresponding positions is arranged to 0.Note that by using Bitmap Control field and Partial Bitmap, it is necessary to Three eight-bit group come represent need with the receiving station of M-BlockAck responses M-BlockAckReq.If in M- BlockAckReq includes 16 bit identifiers to indicate the receiving station of request answer, then M-BlockAck needs 14 eight positions Group.If only indicating the receiving station of request answer using bit vector in M-BlockAckReq, M-BlockAck needs at least 12 eight-bit group.Therefore, Bitmap Control field of the invention and Partial Bitmap reduce opening in M-BlockAckReq signals Pin.When higher and/or when the quantity of target receiver for multicast is larger with the quantity of the associated associated stations of AP, the present invention carries Desired address method is supplied.

Fig. 9 A show the multicast block being used to utilize with delay policy and response of another embodiment according to the present invention The sequential of (M-BlockAckReq) and the reliable multicast transport of multicast block response (M-BlockAck) exchange is asked in response.Send Device/AP/ originator to multiple receiver/STA (such as receiver 1 and 2, but do not include receiver 3) multicast data transmission unit/ The block of packet/frame.Each data cell/packet/frame includes sequence number or frame identifier.The sequence number is incremented by 1 every time.Utilize CDMA, TDMA, poll or multichannel poll are transmitted.After it have sent the block of multicast packet, transmitter is to multicast receiver Transport multicast BlockAckReq (M-BlockAckReq) signal.M-BlockAckReq signals include block ACK requests (BAR) control Field, block ACK request (BAR) information fields and reliable multicast receiver (RMR) information field processed.BAR control fields and BAR letters Ceasing field includes the flow identifier symbol (TID) and block ACK start sequence numbers of the request of multicast BlockAck (M-BlockAck) frame.It is described Start sequence number is the sequence number of the first frame of M-BlockAckReq requests M-BlockAck.The reliable multicast receiver information word Section includes the receiver identifier list for sending the block Ack requests of M-BlockAck.In figure 9 a, the identifier is to be used to connect Receive the identifier of device 1 and 2.The identifier can be the MAC Address, association ID or IP address at the station (if the present invention exists IP layers of execution/operating).Selectively, the RMR information fields include Bitmap Control field and bitmap field to indicate to send M- The receiver of BlockAck requests.Each in the bitmap indicates the receiving station for asking block Ack.BlockAckReq is asked Receiver identifier list or bitmap in each receiver/receiving station (be receiver 1 and receiver in the example of Fig. 9 A 2) according to the multicast receiver order/time ordered pair M-BlockAckReq originator determined in M-BlockAckReq lists or bitmap Response block response (Ack) signal/frame or other signal/frames.Selectively, receiver is identified according to as M-BlockAckReq Symbol list or M-BlockAckReq bitmaps in receiver identifier sequence function order send its block Ack signals/frame/ Message.Multicast receiver is getting out M-BlockAck and the M-BlockAck sound of its delay is sent after the transmission that has an opportunity Should.Once getting out the content of M-BlockAck signals/frame/message, multicast receiver earliest may transmission opportunity at it (TXOP) M-BlockAck of delay is sent.M-BlockAck responses, which have in M-BlockAckReq signals/message/frame, specifies Start sequence number data cell/packet/frame block reception state.M-BlockAckReq originator is with ack signals/frame/message Or other signal/frame/acknowledgement messagings receive M-BlockAck signals/frame/message with response.Send out in M-BlockAckReq sources Device is with unicast transmission ack signals/frame/message.Receiver/the STA being not included in BlockAckReq lists or bitmap is not replied This BlockAckReq originator.In Fig. 9 A illustrated embodiments, receiver 3 does not reply this M-BlockAckReq, because it is not Comprising in the block ack request receivers identifier list or bitmap of this BlockAckReq.

Fig. 9 B show that the utilization that is used for of another embodiment according to the present invention has delay policy and unresponsive multicast The sequential of (M-BlockAckReq) and the reliable multicast transport of multicast block response (M-BlockAck) exchange is asked in block response.Hair Device/AP/ originator is sent to multiple receiver/STA (such as receiver 1 and 2, but do not include receiver 3) multicast data transmission list The block of member/packet/frame.After it have sent the block of multicast packet, transmitter/AP/ originator is to target receiver transport multicast BlockAckReq (M-BlockAckReq) signals/frame/message.Reliable multicast receiver (RMR) information field includes hair Go out the receiver identifier list of the block Ack requests of M-BlockAck.In figures 9 b and 9, the identifier is to be used for receiver 1 and 2 Identifier.Selectively, the RMR information fields include Bitmap Control field and bitmap field to indicate to send M- The receiver of BlockAck requests.The receiving station of each position instruction request block ack in bitmap.If use M- Each reception in the receiver identifier list asked without ack features/strategy, BlockAck or bitmap of BlockAckReq Device/receiving station (being receiver 1 and receiver 2 in the example of Fig. 9 B) is when receiving M-BlockAckReq not with response (Ack) signal/frame/message carries out response to M-BlockAckReq originator.Using delay block Ack strategies, block Ack request row Multicast receiver in table or bitmap is getting out M-BlockAck and M-BlockAckReq sources is being sent out after the transmission that has an opportunity Device carries out response with the M-BlockAck postponed.Once get out the content of M-BlockAck signals/frame/message, multicast reception Device earliest may transmission opportunity transmission M-BlockAck at it.If using M-BlockAck without ack features/strategy, M- BlockAckReq originator does not carry out response with Ack signals/frame/message and receives M-BlockAck signals/frame/with response disappearing Breath.Receiver/the STA being not included in BlockAckReq lists or bitmap does not reply this BlockAckReq originator.Scheming In 9B illustrated embodiments, receiver 3 does not reply this M-BlockAckReq, because it is not included in the block of this BlockAckReq In ack request receivers identifier list or bitmap.Generally, using delay block Ack strategies, M-BlockAckReq or M- BlockAck signals/frame/message includes Ack policy fields.When in M-BlockAckReq or M-BlockAck signals/frame/message During middle setting Ack policy fields, response is not required when receiving this signal/frame/message in expression.Otherwise, it is desirable to Ack responses.It is right It can be carried out in the setting of Ack policy fields independently of M-BlockAckReq or M-BlockAck signals/frame/message.These words All four combinations of hop count value can use.

Fig. 9 C show that the multicast block response for utilizing with multichannel poll of another embodiment according to the present invention please Seek the sequential of (M-BlockAckReq) and the reliable multicast transport of multicast block response (M-BlockAck) exchange.Multichannel poll source Send out device/transmitter/AP transmission multichannel poll (MP) frames.MP frames are transmitted comprising downlink (from MP originator/AP to receiver/STA) The scheduling of time (DTT) and/or uplink (originator/AP from STA to MP) transmission time (UTT)/time distribution.MP originator/ AP can dispatch DTT and UTT.DTT or UTT has initial time and duration.The DTT cycles be used for the transmission of MP originator/AP with Multicast or unicast data unit/frame/grouping block that multicast or unicast address are associated.The UTT cycles be used for STA to MP originator/ AP transmission data blocks.In MP originator/AP to after multiple receivers/STA multicast data transmissions unit/packet/frame block, the phase passes Defeated multicast BlockAckReq (M-BlockAckReq) signal/frame/message.Multicast receiver/receiving station/destination is with its own M-BlockAck signals/frame in UTT responds M-BlockAckReq originator is asked with response M-BlockAckReq Data cell/packet/frame block reception state.As illustrated in the embodiment of figure 9 c, AP/MP originator transmission has multicast address The first multicast packet block, have another multicast address the second multicast packet block and other multicast blocks and/or unicast data. After transmitting the first multicast packet block, AP/MP originator sends M-BlockAckReq1.Each target of first multicast packet block Receiver/STA (such as receiver 1 and 2) rings M-BlockAckReq1 with its M-BlockAck within its UTT cycle Should.Except M-BlockAck, receiver/STA can also send other upstream datas within its UTT cycle.Similarly, transmitting After second multicast packet block, AP/MP originator sends M-BlockAckReq2.Each intended recipient of second multicast packet block Device/STA (such as receiver 3 and 4) responds M-BlockAckReq2 with its M-BlockAck within its UTT cycle.Can Selectively, can in different MP DTT (not being the agreement DTT that corresponding multicast packet unit/packet/frame block is sent) or M-BlockAckReq is sent in different MP sequences/pulses.Furthermore it is possible to sent in multiple MP DTT multicast packet unit/ Packet/frame block, then by multicast transmitter in the last MP DTT of transmission data block or in following/MP DTT below M-BlockAckReq is sent, to ask M-BlockAck with this multicast packet unit/packet/frame block of response.

The present invention can be also used for station (STA include station, AP and mesh AP) to exchange for wireless mesh network, from group Multicast and the block ack of broadcast transmission ask sum block in knitmesh network (ad hoc network) or independent basic service set (IBBS) ack.It can be used for the reciprocity multicast between station.Method of the invention can be utilized by the multicast packet being used for transmission by standing Multicast block ack requests are sent to multiple receiving stations, such as in video conference or other peering services.Receiving station is with multicast block Ack responds multicast block ack requests originator.

Figure 10 is the block diagram of the exemplary realization of the present invention.Because STA and/or AP (specific STA) can be transmitter, connect Device and transceiver are received, single block diagram is used to show the wireless communication module with wireless transmitter/receiver.That is, it is described wireless Emitter/receiver can be transmitter, receiver and transceiver.The present invention includes mainframe computer system and communication module (nothing Line).The mainframe computer system can be all-purpose computer or special-purpose computing system.The mainframe computer system includes centre Manage device (CPU), memory and input and output (I/O) interface.Wireless communication module includes MAC and baseband processor, wireless transmission Device/receiver and one or more antennas.Radio signal is launched and received to antenna.Wireless transmitter/receiver carries out wireless Electric signal processing.MAC controls that MAC and baseband processor be used for transmission/receive and data framing (data framing), Modulating/demodulating, coding/decoding.At least one embodiment of the present invention may be embodied as mainframe computer system or wireless communication Mould routine in the block (routine) is to carry out the transmission of data and control signal and reception.That is the block diagram of Figure 10 may be embodied as Hardware, software, field alterable into gate array (FPGA), application-specific integrated circuit (ASIC), Reduced Instruction Set Computer (RISC) or It is combined.In addition, process can be in mainframe computer system or wireless communication module described in above-mentioned various flow charts and word Or performed in the combination of mainframe computer system and wireless communication module.Therefore the block diagram is fully able to various method/processing Hardware, Software thread become gate array (FPGA), application-specific integrated circuit (ASIC), Reduced Instruction Set Computer (RISC) or It is implemented in being combined.

It is appreciated that the principle of the present invention can use various forms of hardware, software, firmware, application specific processor and its group Close and realize, it is preferable that the principle of the present invention can be realized as the combination of hardware and software.Also, software can be used as embedding Enter in program storage unit (PSU) Shangdi application program to realize.Application program can be uploaded to comprising any appropriate architecture Machine is simultaneously executed by it.Preferably, which performs on the computer platform with hardware, and the computer platform for example has There are one or more central processing units (CPU), random access storage device (RAM), input and output (I/O) interface.Computer platform It can also include operating system and micro-instruction code.Various processing described herein and function can be can be by the micro- of CPU processing A part for instruction code or a part for application program, or combinations thereof.In addition, various ancillary equipment can be connected to Computer platform, such as additional-data storage unit and print unit.

It will be further appreciated that because some system building blocks and method described in attached drawing are preferably real by software Existing, there may be not for the programmed mode of actual connection principle according to the present invention between system element (or processing step) Same part.Based on the principle of the present invention, those of ordinary skill in the art are contemplated that for realizing the above-mentioned of the principle of the invention With other modes or structure.

Claims (14)

1. a kind of method of multicast, including：

The multiple data cells of multicast；

Multicast receives the request of the multiple data cell for response；

Receive the signal in response to the request；

Judge whether to receive the signal in response to the request from all receivers of the request for the first time；

If judging it is affirmative for the first time, based on received signal, the multiple data cell is judged for the second time Reception state；

If it is fixed to judge whether for the first time, judge whether the quantity of the request for the multiple data cell of response exceedes Retry threshold value；

If without departing from threshold value is retried, the request for the multiple data cell of response is updated, to having received from it In response to the request for response signal each response receiver remove mark, and again multicast for response The request；

Otherwise, second is carried out to judge.

2. according to the method described in claim 1, further include：

After described second judges, judge whether the service life of the data cell expires for the third time；

Judge in response to the third time, again data cell described in multicast.

3. according to the method described in claim 1, further include：Response is received for each multicast request.

4. according to the method described in claim 1, further include：For each signal transmission response received.

5. according to the method described in claim 1, wherein postpone the signal.

6. according to the method described in claim 1, further include：Upstream data is received from the receiver.

7. according to the method described in claim 1, wherein, the mark is associated identifiers, Media Access Control address, interconnection One of fidonetFido address and be comprised in bitmap set in.

8. a kind of device for multicast, including：

Wireless communication module for the multiple data cells of multicast；

The request of reception of the wireless communication module also multicast for the multiple data cell of response；

The wireless communication module receives the signal in response to the request；

The wireless communication module judges whether to receive in response to described from all receivers of the request for the first time The signal of request；

In the case where first time judges to be affirmative, the wireless communication module is based on described in second of judgement of received signal The reception state of multiple data cells；

In the case where judging whether to determine for the first time, the wireless communication module is judged for the multiple data cell of response Whether the quantity of request, which exceedes, retries threshold value；

If not less than threshold value is retried, the wireless communication module updates the request for the multiple data cell of response, right Receive from it removing mark in response to each response receiver of the signal of the request for response；And again The request of the multicast for response；

Otherwise, the wireless communication module carries out second of judgement.

9. device according to claim 8, further includes：

The wireless communication module judges whether the service life of the data cell expires for the third time after judging at described second； And

The wireless communication module judges data cell described in multicast again in response to the third time.

10. device according to claim 8, wherein, the wireless communication module is received also for each multicast request should Answer.

11. device according to claim 8, wherein, the wireless communication module is passed also for each signal received Defeated response.

12. device according to claim 8, wherein, the signal is delayed by.

13. device according to claim 8, wherein, the wireless communication module also receives upper line number from the receiver According to.

14. device according to claim 8, wherein, the mark is associated identifiers, Media Access Control address, mutually One of networking protocol address and be comprised in bitmap set in.