CN101552732B

CN101552732B - Hybrid grid route selection protocol

Info

Publication number: CN101552732B
Application number: CN2009101410604A
Authority: CN
Inventors: 刘航; 李钧; 绍拉伯·马瑟
Original assignee: Thomson Licensing SAS
Current assignee: InterDigital CE Patent Holdings SAS
Priority date: 2005-03-10
Filing date: 2005-03-10
Publication date: 2012-03-14
Anticipated expiration: 2025-03-10
Also published as: CN101552732A

Abstract

The invention discloses a route selection method through establishing a route between a source node and a destination node by the node between the source node and the destination node using the medium access control address in a wireless grid network. The invention also discloses a method for entering into a multicast group in the wireless grid network by selecting the route by the node using the medium access control address.

Description

Hybrid grid route selection protocol

The application is denomination of invention the dividing an application for " hybrid grid route selection protocol " of the one Chinese patent application No.200580048992.4 of submission on March 10th, 2005.

Technical field

The present invention relates to a kind of routing mechanism that is used for automated topology study and Path selection.Particularly, the present invention relates in wireless local area mesh network, confirm route based on media access control address.

Background technology

Wireless local area mesh network is also referred to as the ad hoc network based on WLAN, comprises the two or more nodes that also intercom mutually directly or indirectly through the radio link interconnection.This network can be connected to the Internet or other networks through inlet.In wireless local area mesh network, used IP layer routing protocol to find the route from the source node to the destination node.IP layer ad hoc routing protocol is based on the IP address.Yet some equipment such as the WLAN access point are transmitted packet based on IEEE 802.11 media interviews control (MAC) address, and only operate in link layer (layer 2).In addition, because packet need not passed through IP layer (layer 3), transmit data usually than fast at the IP layer at layer 2.

Ad Hoc distance vector (AODV) agreement as required is a kind of ad hoc routing protocol of the IP of operating in layer.This agreement can be supported clean culture and multicast route discovery.Route is based on discovery as required.When the source is wanted when destination node send to be divided into groups, if the source does not have to the route of destination node and needs this route, then the source is found to the route of destination through broadcasting route request information on network.This message comprises IP address and other necessary informations of source node and destination node.Destination node or have to the node of effective route of destination node and reply this request through sending route replies to source node.Route requests and route replies message be used for transmitting and each of the intermediate node of reverse path/route in set up routing table.If in given route lifetime, do not use this route, the route of then being set up expires.Route Selection has reduced because the influence of the inefficacy route of network topology change (for example, node motion and fault) and keep the needs without route as required.Yet, because source node need be set up route before can sending data, so introduced route discovery delay.Source node also need cushion data during route discovery.

Aim sequence distance vector (DSDV) is to answer the formula routing protocol earlier to wireless local area mesh network.Node switching Route Selection control messages in the network makes the routing table at each node place all be included in the information of all destination nodes in the wireless local area mesh network.Based on routing table packet is forwarded to destination node from source node along the path by intermediate node.For the path of remaining valid, and avoid the Route Selection loop that causes owing to link/node fault and network topology conversion, each node not only periodically transmission route upgrade, but and broadcast this renewal immediately in the important fresh information time spent.Though DSDV allows to use the MAC Address of layer 2 or the IP address of layer 3 to transmit grouping, and does not have route discovery delay, because spread all over the Route Selection information broadcast of network, this has caused high relatively Route Selection expense.Especially the node in network moves and during the network topology structure frequent variations quickly, and it is current that the major part of network capacity is used to keep routing information.In addition, because processing and battery limitation or other reasons, some nodes possibly can't be transmitted the packet that is derived from other nodes.Yet above-mentioned each node of agreement hypothesis is all agreed to relay packet based on request to other nodes, and does not consider non-forward node.

In wireless local area mesh network, two or more nodes are through IEEE 802.11 link interconnects.Each node all has unique IEEE 802.11 media interviews control (MAC) address.When source node when destination node is sent packet, source node need be known the path/route from the source node to the destination node.

Neededly be based on the routing mechanism that the path was found and set up to target MAC (Media Access Control) address.The problem that the present invention solved is, how source node finds and be established to the path of destination node based on IEEE 802.11 MAC Addresss of destination node in wireless local area mesh network.

Summary of the invention

WLAN (WLAN) mesh comprises the two or more nodes through IEEE 802.11 link interconnects.Each node will be participated in the routing protocol to automated topology study and Path selection.The invention provides a kind of mechanism that is used for finding route based on IEEE 802.11 media interviews control (MAC) address.This mechanism is supported as required route discovery simultaneously and is answered the formula route to set up earlier.Route can found and set up to this mechanism satisfying service quality (QoS) demand that real-time multimedia is used, and keep this route.In addition, this mechanism is supported non-forward node.

Described and a kind ofly in wireless mesh network, between source node and destination node, set up the method that route is selected route through using media access control address by the node between source node and the destination node.Node has also been described in order to select route to add a kind of method of the multi-broadcast group in the wireless mesh network through using media access control address between said node and multi-broadcast group, to set up route.In both of these case, can be through using as required Route Selection or answering the formula Route Selection to set up route earlier.Although aspect wireless local area mesh network, describe describedly when of the present invention here, the networking of setting up route therein is not limited to wireless local area mesh network, and can be any type of wireless mesh network.Access point with acting server can add wireless mesh network.Website is associated with access point, but website is not the member of wireless mesh network, therefore take place and the communicating by letter of website through access point, and this communication for related website be transparent.

Description of drawings

When combining accompanying drawing to understand following details to describe, can understand the present invention best.The concise and to the point following diagram of describing below accompanying drawing comprises:

Fig. 1 has described and has illustrated with route requests (RREQ) message flooding and wireless local area mesh network that reverse path is set up to mesh.

Fig. 2 has described the wireless local area mesh network that clean culture that route replies (RREP) message is shown and forward path are set up.

Fig. 3 A has described the wireless local area mesh network that floods that route announcement (RANN) message that is used for setting up to the formula of answering earlier of the route of RANN message initiator is shown.

Fig. 3 B has described and source node is shown has sent the wireless local area mesh network of free RREP message with the reverse route that is established to source node.

Fig. 4 show node as required with set up route with answering formula earlier, and handle the diagram of the method for Route Selection control messages according to principle of the present invention.

Fig. 5 has described the wireless local area mesh access point with a plurality of related websites.

Fig. 6 shows the sketch map according to wireless local area mesh access point of the present invention.

Fig. 7 A shows new node and adds route requests (RREQ) message the flooding to mesh of multi-broadcast group to ask it.

Fig. 7 B has described route replies (RREP) message that sends it back the promoter of route requests (RREQ) message through different multicast tree members.

Fig. 7 C shows the promoter that transmission route activates route requests (RREQ) message of message.

Fig. 7 D shows the new node that adds multi-broadcast group to.

Fig. 8 A shows the multicast leaf node and how to withdraw from/leave multi-broadcast group.

Fig. 8 B shows the multicast tree after pruning.

Fig. 9 A shows the multicast tree with disconnecting link.

Fig. 9 B has described downstream node and has attempted for the link that breaks off bypass being set.

Fig. 9 C shows downstream node and receives route replies (RREP) message from titular multicast tree member.

Fig. 9 D shows downstream node and activates new link.

Fig. 9 E has described the new multicast tree that bypass is set for the link that breaks off.

Embodiment

Therefore the routing function of execution level 2 of the present invention can will divide into groups to transmit and be forwarded to destination node from source node based on IEEE 802.11MAC address.The present invention supports as required Route Selection simultaneously and answers the formula Route Selection earlier.In addition, some nodes can only send or receive data, but because processing and battery limitation or other reasons and can not transmit the data that are derived from other nodes.The present invention can handle these non-forward node.Can routing mechanism of the present invention be used for client-server application configuration/topology, peer application configuration/topology and mixing application configuration/topology.

Hybrid grid Route Selection as required is similar with IP layer routing protocol AODV, all is based on route requests and route replies message.For the hybrid network of layer 2 Route Selection as required, to want to send when dividing into groups when source node to some destination nodes, it is used for the routing table of route the source node inspection.If there is effective route, then source node is given next jumping to this destination node specified in the routing table with packet forward.If there is not effective route, then source node is initiated route discovery through broadcasting route requests (RREQ) message.Be different from AODV; RREQ message comprises the promoter IEEE 802.11MAC address (not being the IP address) with sequence number and optional layer 3 information, and has the up-to-date aim sequence of knowing number and to the destination node MAC Address (not being the IP address) of optional layer 3 information of this destination node.RREQ message also comprises message id, route metric, useful life (TTL) and route lifetime.Before initiating route requests, RREQ message will make self sequence number increase progressively.

Through broadcasting RREQ message or other grid Route Selection control messages such as the following RANN message that will describe, IEEE 802.11 broadcasting MAC Addresss can be used as the destination address of the grid Route Selection control messages of being transmitted.Possibility is the special I EEE 802.11 multicast MAC Addresss that branch is used in the grid Route Selection control messages that floods (network Route Selection control group address).All grid nodes have been specified in this address.Grid node receives the message of pointing to this grid Route Selection control group address.Non-grid node can not receive the message of pointing to this grid Route Selection control group address.

With reference to the Fig. 1 that has described wireless local area mesh network, node 105 is source nodes, and node 110 is destination nodes.Other all nodes 115 are potential/possible intermediate nodes, and they are can be through the node of its pass-along message/grouping/data between source node 105 and destination node 110.Based on selected route/path, confirm to be used for from the set of source node to the intermediate node 115 of the discrete cell of destination node transmission content.Source node 105 and destination node 110 band texture or shades are so that distinguish they and potential/possible intermediate node 115.It should be noted that in another example, (Fig. 1) can be the intermediate node in this instance as the node of source and destination node now, and other nodes become the source and destination node.In Fig. 1, source node 105 uses route requests (RREQ) the message wireless local area mesh network that floods.Set up reverse path based on this route request information.

In a single day node receives RREQ message, then checks originator address and message ED, whether once to meet this RREQ message before watching.If this is a RREQ message, then node upgrades metric field through increasing from the node of its reception RREQ message and the link cost between this node itself, in its routing table, is established to this promoter's reverse route then.If this node is a destination node; If perhaps node has the undue effective route to the destination; And the sequence number of this destination node is big as represented in the RREQ message at least, and then this node is through returning route replies (RREP) message unicast the promoter and respond.Otherwise this node is propagated RREQ message with new tolerance.If this is not a RREQ message, then this node receives the node of RREQ message and the metric field that the link cost between this node is updated to the promoter through increasing from it.If newly measure less than the tolerance that in the routing table of node, is write down, then the reverse route of this node updates.Otherwise, then abandon this RREQ message.If this node satisfies above-mentioned requirements, then use RREP message to reply the promoter.Otherwise this node is propagated RREQ message with new reverse route metric.The promoter that reverse path/route is used for RREP message is sent it back RREQ message is used for the two-way communication between source node and the destination node in addition to set up forward path.

Through clean culture RREP message is sent it back the promoter of RREQ message, to set up forward path.This RREP message comprises promoter's MAC Address, target MAC (Media Access Control) address and optional target zone 3 information, sequence number, tolerance, useful life and the route lifetime of destination node.If the maximum of its current sequence number and the destination sequence number in the RREQ message are then used in the destination node response.The initial value of tolerance is zero.Destination node also is provided with the lifetime of route.If intermediate node responds then uses it to the aim sequence number record with tolerance, and based on route lifetime that routing table entry calculated.

With reference to the Fig. 2 that has described wireless local area mesh network, node 205 is source nodes, and node 210 is destination nodes.Confirmed set to the intermediate node 220 of particular source node 205 and destination node 210.For the route/path between source node 205 and the destination node 210, intermediate node 215 no longer is an intermediate node.Through from destination node 210 to source node 205 clean culture RREP message set up forward path.

RREP message is carried out clean culture through the reverse route of during route requests broadcasting, being set up.When intermediate node received RREP message, intermediate node therefrom receives the node of RREP message through increase and the link cost between the intermediate node itself upgrades tolerance.Intermediate node is set up forward path in its routing table, and gives the promoter of RREQ message with the RREP forwards.If node receives more than one RREP message, then transmit a RREP message.Only when new RREP message comprised bigger aim sequence number or has the identical purpose of better tolerance, this node just upgraded routing table and transmits new RREP message.Otherwise, then abandon new RREP message.Fig. 1 and Fig. 2 show the RREQ message mesh that floods, and set up forward path through clean culture RREP message.The promoter can begin data/transmitted in packets immediately when receiving a RREP message, and if find better route, then can upgrade its routing information after a while.

Node can have a plurality of IEEE 802.11 wave points.Node has unique node identifier, i.e. IEEE 802.11 MAC Addresss of node, and each interface also have IEEE 802.11 MAC Addresss of himself.The MAC Address of node is used for RREQ and RREP message and following other Route Selection control messages that will describe.When many interface nodes were broadcasted RREQ message, this node can be through this RREQ message of total interface broadcasting.When many interface nodes responded RREQ message through clean culture RREP message, this node sent RREP message to the interface that receives corresponding RREQ message through it.

Routing table comprises the clauses and subclauses to destination node.Each clauses and subclauses all comprises target MAC (Media Access Control) address and its optional layer 3 information (layer 3 agreement and the address supported; The IP address of destination node for example), aim sequence number, next-hop mac address, the interface that arrives next jumping, upstream node tabulation and use interface, state and the Route Selection mark (for example, effective, invalid) of this route, to the tolerance and the route lifetime of destination.When using route at every turn, the lifetime of upgrading this route.If in route lifetime, do not use this route, then this route become invalid.When the deletion timer of invalid route expires, will delete this invalid route.The promoter can begin transfer of data immediately when receiving a RREP message, and if find better route, then can upgrade routing information after a while.When intermediate node received packet, this intermediate node was checked routing table based on target MAC (Media Access Control) address.If there are the effective clauses and subclauses to this destination, then intermediate node forwards the packet to next specified in these Route Selection clauses and subclauses jumping.Before arriving destination node, this process will continue.

In Route Selection as required, only keep presently used route.This has reduced the Route Selection expense.Yet because source node must be set up route before can sending data, this has caused extra delay.Source node also need cushion data during route discovery.In order to reduce route discovery delay, can use and answer the formula Route Selection earlier.In addition, under many nodes and situation that specific nodes is communicated by letter,, then need significant control traffic carrying capacity if each in these nodes all is found to the route of this specific nodes separately.For example, the many nodes in the mesh visit the Internet or other networks through the one or more Ingress nodes that this mesh are connected to the Internet or other networks.It is desirable for Ingress node and answer formula ground declaration route to it in mesh earlier.The present invention will be as required route discovery with answer the combination of formula route announcement earlier.Node can be disposed by network manager's dominance, or confirms that according to specific policy recessiveness the formula Route Selection is answered in execution earlier in mesh.For example, strategy is that all grid Ingress nodes all should be carried out and answer the formula route announcement earlier.With reference to Fig. 3 A, node 310 is declared himself through periodically broadcasting not requested route announcement (RANN) message, thereby other nodes 315 in the mesh can learn the route of RANN message initiator 310.In other words, the node of initiating RANN message uses the not requested RANN message wireless local area mesh network that floods, so that be established to the route of himself with answering formula earlier.When many interface nodes were broadcasted RANN message, these many interface nodes can be broadcasted this RANN message through its total interface.RANN message comprises the IEEE 802.11MAC address (not being the IP address) of the initiator node with aim sequence number and optional layer 3 information.RANN message also comprises route metric, useful life and route lifetime.Notice that what be different from RREQ message is that the destination address in the RANN message is the MAC Address of RANN message initiator, because this RANN message is used for answering earlier formula ground to be established to the route of RANN message initiator in mesh.

When node 315 received RANN message, this node received the node of RANN message and the metric field that the link cost between this node itself is updated to the promoter of RANN message through increasing from it.If this node does not have in its routing table to effective route of this destination node (that is, RANN message initiator 310), then this node is created to the route of this destination node in its routing table.This node is with new tolerance one or more to adjacent node broadcasting RANN message through in its interface.When this node has the effective route to this destination; Only when RANN message comprises bigger aim sequence number or has the identical aim sequence of better tolerance; This node just upgrades its routing table, and broadcasts RANN message with new tolerance to adjacent node.Otherwise, then abandon this RANN message.In this manner, in mesh, be established to the route of RANN message initiator.

With reference to Fig. 3 B, to want when destination node 310 is sent packet when source node 305, this node possibly acquire the forward path of this destination node 310 from the route announcement of destination node.In this instance, this node can transmit grouping immediately.Yet it also is possible not having from destination node 310 to source node 305 reverse route.Two-way communication if desired, then source node 305 can send free RREP message to node 310 clean cultures ground through intermediate node 320 along the forward path of being set up by the RANN message of destination node 310.This RREP message has been set up the reverse route of source node 305.

Some nodes are only wanted as source node or destination node and are added wireless local area mesh network, promptly do not transmit the business that is derived from other nodes.Node can be non-forward node by administrator configurations, or is confirmed as non-forward node based on specific policy.For example, such policy is, if the energy content of battery of node is lower than threshold value, then this node will become non-forward node.Non-forwarding grid node sends RREQ message when it wants transmission to divide into groups.Have only when this non-forward node is the destination node in the RREQ message that receives, just reply route request information.If this non-forward node is not the destination node in the RREQ message that receives, do not reply route request information.Non-forward node receives RANN message, with the promoter's that learns RANN message route.Non-forward node sends RANN message, makes to answer formula ground to set up the route of pointing to this non-forward node earlier.Yet non-forwarding grid node is not transmitted any Route Selection control messages to adjacent node, comprises RREQ, RREP and RANN message.Through doing like this, do not exist the route of non-forward node as intermediate node.

If link breaks off, then the affected source node to active paths sends routing error (RERR) message.The upstream node of disconnecting link promptly near the node in source, is initiated RERR message.Before sending RERR message, it is invalid that this node also will damage routing label, and the tolerance of damage route is made as infinity, and number increases progressively owing to this link failure in the routing table makes the aim sequence of the destination that can not arrive.RERR message comprises because the tabulation of all destinations that can not arrive of this link failure and they sequence number after increasing progressively.This node is to its one or more these RERR message of its upstream neighbors broadcasting.For many interface nodes, send RERR message through interface with route of using this faulty link.When adjacent node when its downstream node receives RERR message, whether the adjacent node inspection has the route of using downstream neighbor to listed destination.If have, be invalid then, and the tolerance of these routes is made as infinity these routing labels.Give upstream node with the RERR message propagation then.When source node received RERR message, source node was initiated route discovery again.If when node receives the packet with target MAC (Media Access Control) address (active/effective route that this MAC Address does not have), then this node is created the RERR message to destination node, and this RERR message is sent to its upstream neighbors.

Local connectivity management is periodically sent beacon (HELLO message) to adjacent node by node and is realized.The node that receives beacon from adjacent node upgrades the route lifetime related with this adjacent node its routing table.If node can not receive the beacon to given Hello_life from adjacent node, the link that then arrives this adjacent node breaks off, and in routing table, upgrades the routing information to this adjacent node then.

Fig. 4 show node desirably with the method for setting up route with answering formula earlier and handling the Route Selection control messages according to principle of the present invention.In step 402, node determines whether to answer the formula route discovery earlier.This information can perhaps be obtained through aforesaid strategy is recessive by the configuration of network manager dominance.Answer the formula route discovery if desired earlier, then in step 404, periodically send RANN message.If do not need to answer the formula route earlier, then node returns idle condition.In step 410, when node received new packet from upper layer application, whether this node inspection had the forward path/route (step 412) to destination node.If no, then this node is initiated route discovery (step 414) as required through sending RREQ message.This node is waited for corresponding RREP message.In case receive RREP message (step 416), then set up forward direction route (step 422), and begin to transmit data (step 428).If the RREQ information drop-out then can allow source node to retransmit this RREQ message sets number of times (step 418).If after the maximum retransmission of RREQ message, still do not receive RREP message, then can not arrive (step 420) through this destination node of error message notification applications.If source node has the forward direction route, then whether the source node inspection has the reverse route (step 424) that is used for two-way communication.If the forward direction route is to set up through the RANN advertisement of destination node, then possibly there is not reverse route.Under the situation of one-way communication that reverse route can be used or two-way communication, source node transmits data immediately in step 428.Under the situation of the two-way communication that does not have reverse route, source node sends free RREP message (step 426), to set up reverse route.In case sent free RREP message, source node then can transmit data (step 428).

In step 440, the node in mesh receives RANN message, then is provided with/set up/returns to the promoter's of RANN message route (step 424).If this node is a non-forward node (step 444), then do not transmit RANN message (step 448).If this node is a forward node, then transmit RAISIN message (step 446).When node receives RREQ message in step 450, be provided with/set up/recover reverse route (step 452).Node determines whether it is non-forward node (step 454).Only at this node when being destination node specified in the RREQ message (step 460), non-forward node is just replied this RREQ message (step 462) through the promoter who the RREP message unicast is sent it back RREQ message.If this node is not a destination node, then non-forward node is not transmitted RREQ message (step 464), but abandons RREQ message.For forward node, if having the effective route (step 456) to destination node if this node is destination node or this node, then this node responds (step 462) through the promoter who route replies (RREP) message unicast is returned RREQ message.Otherwise propagate RREQ message (step 458).When node receives RREP message in step 470, this route (step 472) of then setting/establishment/recovery.If this node is that non-forward node or this node are the destination nodes (step 474) of this RREP message, then this node is not transmitted RREP message (step 478).Otherwise, then transmit this RREP message (step 476).When node detection to link failure or when node receives RERR message (step 480), the route (step 482) that this node deexcitation has damaged.If this node is source node (step 484), then new route (step 490) is found/learned to this node.Otherwise,, then transmit RERR message (step 488) if this node is not a non-forward node (step 486).If this node is non-forward node, then this node is not transmitted RERR message (step 492).

A plurality of websites can be associated with the access point (AP) among the WLAN.With reference to Fig. 5, node 505 is the AP that add mesh.Yet website 510 is not the part of wireless local area mesh network 525.Website 510 forms the network/subnet based on foundation structure with access point 505.Grid AP 505 is as the acting server of these websites 510, and Route Selection is transparent for non-mesh stations 510.When grid AP 505 forwardings are derived from the packet of related website 510, be found to the route of destination node.Grid AP 505 also through to RREQ message initiator clean culture RREQ message, responds the RREQ message of associated stations.Grid AP 505 declares the route of related website 510 through broadcasting RANN message.Can use single RANN message to declare to have a plurality of destination addresses of independent sequence number, optional layer 3 information, useful life (TTL), tolerance and route lifetime.Each destination address is corresponding with a website.

Fig. 6 shows the block diagram of the details of the grid access point (node/AP 505 among Fig. 5) with acting server 600.Grid AP with acting server 600 has two logic interfacings.One is website transmission/reception (TX/RX) interface module 645 of communicating by letter with related website, and another is mesh transmission/reception (TX/RX) interface module 655 of communicating by letter with mesh.These two logic interfacings can use two to operate in the physical I EEE802.11 wave point (each physical interface is corresponding with a logic interfacing) of different channels or use single IEEE 802.11 wave points to realize.Site control module 650 is carried out site control.Grid routing selecting module 605 is responsible for route data in mesh.Grid routing selecting module 605 comprises grid route discovery unit 610, is used for sending route requests so that be found to the route (carrying out Route Selection as required) of the destination node of wireless local area mesh network.Grid routing selecting module 605 also comprises network route announcement unit 615, is used for sending RANN message (carry out and answer the formula Route Selection earlier) in mesh.620 pairs of received Route Selection control messages of Route Selection message processing unit are handled, and reply/transmit the route control messages.Break off if detect link, then route holding unit 625 keeps route, and produces routing error message.Grid routing selecting module 605 also remains on routing table 630 in its high-speed cache.Data processing unit 635 based on this routing table send/receive/transmit packet.Grid routing selecting module 605 is through mesh TX/RX interface module 655 and mesh interfaces.Related website of station proxy 640 bridge joints and mesh.Station proxy 640 is delivered to routing selecting module 605 with the associated stations dot information from related control module 650.Station proxy 640 interacts with routing selecting module 605 so that (for example when station proxy 640 is transmitted the packet that is derived from related website, be found to the route of destination node to related website execution Route Selection and data forwarding function; Respond the RREQ message of related website, and through in mesh, initiating the route that RANN message is declared related website).

The present invention supports multicast and singlecast router to select.Keep independent multicast routing table by node.With above-mentioned clean culture as required route discovery similar be that multicast finds as required that based on route requests and route replies message this is also similar with IP layer routing protocol AODV.Node can dynamically add or leave multi-broadcast group at any time.Each multi-broadcast group all has multi-broadcast group guide (leader).The group guide keeps the multi-broadcast group sequence number.Under the situation that detects multi-broadcast group guide fault, create new group guide, thereby do not have the central point of fault.

When node was wanted to add multi-broadcast group, node was to all grid node broadcasting RREQ message.This RREQ message comprises promoter's MAC Address, current sequence number, optional layer 3 information (supporting layer 3 agreements and address; IP address for example), the up-to-date sequence number of knowing, message id, tolerance, the useful life parameter of target MAC (Media Access Control) address (that is, to be added multi-broadcast group address), group and add mark.Any member of multicast tree can respond RREQ message, but has only the member of multicast tree to respond.Non-member node (member of non-multicast tree) does not respond RREQ message, but is created to promoter's route/path.Then, non-member node is transmitted this RREQ message to adjacent node.To be described in detail this below.The promoter waits for the time limit of discovery time section, replys or replys so that receive.If do not reply, then promoter's re-transmission/broadcast ID increases by 1 RREQ message again.Receive reply or surpassed retry limit before, the promoter continues this mode.Do not reply if after maximum reattempt times, receive, then the promoter can become the multi-broadcast group guide of new multi-broadcast group.

When node when another node (not being this group) receives the request that adds multi-broadcast group, this node updates metric field is also added promoter's inactive clauses and subclauses in its multicast routing table to.Each clauses and subclauses in the multicast routing table all have the active or sluggish mark of indication link.For multi-broadcast group, will be not through inactive link forwarding/transmission data/grouping.This node is also set up rule according to singlecast router, in the singlecast router option table, is created to promoter's reverse route/path clauses and subclauses.

Multicast tree comprises the node as the member of multi-broadcast group, and the forward node that is directed against multi-broadcast group.Forward node is the node as the multicast tree member, but is not the member of multi-broadcast group.Forward node has played the effect of " passage " or " pipeline " for received data/grouping/content.Forward node does not use its received data/grouping/content, and received data/grouping/content is lost interest in.If multicast tree institute recorded sequences number at least with RREQ message in entrained the same big, then any member of multicast tree can reply the RREQ message that adds multi-broadcast group.Multi-broadcast group guide always responds the RREQ message that adds this multi-broadcast group.Response adds the node of the RREQ message of multi-broadcast group and sets up rule according to singlecast router, in its routing table, has set up promoter's single broadcast reverse route.Responsive node is also set up the route to the promoter in the multicast routing table.With this routing label is sluggish.Then, responsive node is returned the RREP message unicast promoter of RREQ message.When the node along reverse path receives RREP message, this node updates tolerance, and in its multicast routing table, set up forward path/route.Path/the routing label that in the multicast routing table, be set up is sluggish.This node arrives next jumping with the RREP forwards then.

Each node in the multicast tree has the multicast routing table.The multicast routing table has the clauses and subclauses to each multi-broadcast group.The clauses and subclauses of multicast routing table comprise multi-broadcast group MAC Address, next-hop mac address, the interface to next jumping, multi-broadcast group sequence number, the tolerance to the multi-broadcast group guide, mark (active/inactive and routing label) and route lifetime parameter.During each uses/process route/path, renewal route lifetime parameter.If in specifying route lifetime, do not use this route/path, then this route/path become invalid.

The promoter who adds the RREQ message of multi-broadcast group can receive a plurality of RREP message from the different members of multicast tree.Each replys the potential route/path of all representing this multi-broadcast group.The promoter follows the trail of received replying, and waits for expiring of route discovery period/interval.Then, the promoter selects to have maximum multi-broadcast group sequence number and have to the route of the best quantitive measure of this multi-broadcast group.Have the adding mark that is set to add next jumping through clean culture and come multicast to activate (MACT) message, the promoter activates selected route/path when route discovery period/interval expires.To the selected route/path in the multicast routing table, the promoter enlivens/and inactive mark is set to enliven.Because jump along each of path and all to receive MACT message, so this node activates the route in its multicast routing table, and if this node be not the promoter of RREP message, then with the MACT forwards to next jumping.Before the promoter of RREP message receives MACT message, continue this process.It should be noted that a node can be the member of two multi-broadcast group/trees simultaneously.

Fig. 7 A-7D shows new node " N " and how to add multi-broadcast group.Dark shaded nodes is the member of multi-broadcast group and the member of multicast tree.White nodes is not to be the member's of multicast tree or multi-broadcast group node.Node " N " is a new node of wanting to add multi-broadcast group.The node that serves as a mark with " F " is the forward direction node.Now, with reference to Fig. 7 A, node " N " is a new node of wanting to add multi-broadcast group.Node " N " uses the RREQ message mesh that floods when attempt adding multi-broadcast group.Before RREQ message arrives the node as the member of multicast tree, through being not that the member's of multicast tree node transmits this RREQ message.Fig. 7 B has described the RREP message of returning the new node of hoping the adding multi-broadcast group.Along reverse path this RREP message is sent it back the promoter of RREQ message by different multicast tree members.Fig. 7 C shows the promoter that transmission route activates the RREQ message of message (MACT).Promoter's clean culture of RREQ message has the MACT message of setting with the adding mark of the route/path that is activated to multi-broadcast group.Fig. 7 D shows the new node that adds multi-broadcast group to.The node that will not be multi-broadcast group or multicast tree member is added to forward node, thereby this node becomes the member of multicast tree.

If as multi-broadcast group member's node want to withdraw from/leave this group, then this node uses the crop marks that is set to prune to jump clean culture MACT message to next, and deletes in its multicast routing table the clauses and subclauses of multi-broadcast group.In case the next node along the path receives the MACT message with crop marks of being arranged to prune, then this knot removal is to transmitting the routing information of the node of MACT message to it.If receiving the node of the MACT message with crop marks of being arranged to prune is not the member of multi-broadcast group; And this node becomes leaf node under the situation of deleting the node of hoping to abandon its membership qualification in multi-broadcast group, then himself is wiped out from multicast tree.Leaf node prunes away himself through next jumping clean culture has the MACT message of the crop marks of being arranged to prune to it from multicast tree.If receive the node of the MACT message with crop marks of being arranged to prune and be the member of multi-broadcast group or be not leaf node, then this node can not be pruned itself.

Fig. 8 A shows node " A " to Fig. 8 B and how to abandon its membership qualification in multicast tree and group.Dark shaded nodes is the member of multi-broadcast group and the member of multicast tree.White nodes is not to be multicast tree or multi-broadcast group member's node.The node of marking with " F " is a forward node.If Fig. 8 A shows the multicast leaf node and withdraws from/leave multi-broadcast group.Node " A " clean culture has the MACT message of the crop marks of being arranged to prune, so that abandon its membership qualification in multi-broadcast group and tree.Fig. 8 B shows the multicast tree after the pruning.Node " A " is abandoned its membership qualification from multi-broadcast group and tree after, stay node " B " as leaf node, thereby this node prunes away itself from multicast tree as forward node.

Each Hello_mterval, the node on the multicast tree must receive the transmission from each adjacent node.Transmission comprises multi-case data grouping, RREQ message, Hello message, beacon message or group greeting (GRPH) message.The guide periodically sends GRPH message along multicast tree by group.If node fails to receive any transmission from the adjacent node on the multicast tree in HelloJlife, then the link to this adjacent node breaks off.When link broke off, the node of disconnection dirty (that is, node) far away apart from the multi-broadcast group manager attempted repairing this link.In fact, this is the trial that bypass is set and produces the feasible path of getting back to multicast tree for the link that breaks off.The link that be responsible for to attempt repair breaks off or through finding that the downstream node that optional route comes bypass is set for the link that breaks off sends the RREQ message that adds multi-broadcast group, this RREQ message comprises has indicated the extended field of sending node with group guide's tolerance.The node of response RREQ message must be have enough fresh sequence number (the sequence number here at least with RREQ message in entrained multi-broadcast group sequence number the same big) the member of multicast tree, and must be better than tolerance indicated in the RREQ message to the gerentocratic tolerance of multi-broadcast group.When route discovery period/interval expires, initiate to attempt being provided with the node of the RREQ message of bypass and select route/path, and clean culture has the MACT message of the adding mark that is set to add next jumping, so that activate the route of latest find for the link that breaks off.Set and repair multicast tree if can not add this once more through any branch, the downstream node that the link that is responsible for disconnection so is provided with bypass becomes the new multi-broadcast group guide of new multicast tree.

The multicast tree link that Fig. 9 A-9E shows to breaking off is provided with bypass.Fig. 9 A shows the multicast tree of the link with disconnection.In this instance, the link between node " A " and the node " B " breaks off.Fig. 9 B has described downstream node (node " A ") and has attempted coming for the link that breaks off bypass to be set through the RREQ message of sending request adding multi-broadcast group.Fig. 9 C shows downstream node (node " A ") and receives RREP message from titular multicast tree member.Fig. 9 D shows downstream node (node " A ") and uses the MACT message with adding mark of being arranged to add to activate new link.Fig. 9 E has described the multicast tree of having repaired that is provided with bypass for the link that breaks off.In fact the link that it should be noted that disconnection is not what repair, but through using available route discovery mechanisms to come to be provided with bypass for it.

Similar with clean culture, in order to reduce route discovery delay, the formula Route Selection is answered in support of the present invention earlier.The present invention will be as required route discovery with answer the combination of formula route announcement earlier.For multicast, if this node is the multi-broadcast group guide, then this node can be disposed by network manager's dominance, or confirms according to specific policy is recessive, answers the formula Route Selection earlier so that in mesh, carry out.The group guide who is disposed comes the advertisement multi-broadcast group through periodically broadcasting uncalled route announcement (RANN) message, makes other nodes in the mesh can learn the route of multi-broadcast group.RANN message comprises the IEEE 802.11MAC address (not being the IP address) of the multi-broadcast group with group sequence number and optional layer 3 information.RANN also comprises route metric, useful life and route lifetime.

For example, for multimedia and Video Applications, support that the service quality (QoS) in the WLAN mesh is necessary.In order to support QoS, can in the Optional Field of the RREQ message of having expanded, carry the for example maximum delay of data and the QoS demand of minimum bandwidth requirement.In order to respond or transmit the RREQ message with QoS expansion, node must satisfy the QoS restriction.Otherwise, then abandon this QoS RREQ message.After setting up the QoS route, if detect its no longer satisfied qos parameter of being asked along the arbitrary node in path, then this node sends RERR message to the promoter.RERR message also can be carried such as the available bandwidth of this link and the qos parameter of the current measurement the delay parameter.The promoter can determine to continue to use the route with low QoS, or finds another route.For example, RERR message has indicated that available current bandwidth equals than the low value of being asked before the promoter on the link.The promoter can reduce its source speed, to satisfy the new route that current available bandwidth or discovery have original needs bandwidth.

It is understandable that the present invention can be implemented as the processor of hardware, software, firmware, specific purpose or these several persons' combination, for example in the portable terminal, access point or cellular network.Preferably, the present invention is embodied as the combination of hardware and software.In addition, software preferably is embodied as the application program that is embodied in conscientiously on the program storage device.Application program can upload to the machine that comprises any appropriate configuration, is perhaps carried out by the machine that comprises any appropriate configuration.Preferably, on computer platform, realize this machine, computer platform has the hardware such as one or more CPU (CPU), random-access memory (ram) and I/O (I/O) interface.This computer platform also comprises operating system and micro-instruction code.Here described various processing and function can be the part of the micro-instruction code carried out through operating system or the part (or the two combination) of application program.In addition, various other ancillary equipment such as additional data storage device and PRN device can be connected to computer platform.

It will also be appreciated that; Because the assembly of the composition system described in the accompanying drawing and some in the method step preferably are embodied as software, so the actual connection between the computer module (or treatment step) can be distinguished according to the mode that the present invention is programmed to some extent.Here provide under the situation of instruction, those of ordinary skill in the related art can imagine these and similar realization or structure of the present invention.

Claims

1. method of in wireless mesh network, selecting the route between source node and the destination node through node, said method comprises: use MAC Address to set up said route between source node and destination node; Selected route between source node and destination node is based on hybrid grid Route Selection and answer formula grid Route Selection earlier as required, and wherein said hybrid grid Route Selection as required also comprises:

Receive route request information through said node;

Through inspection originator address and message id; Whether once to meet this route request information before watching; Carry out first by the said node that receives route request information and confirm, confirm whether said route request information is first route request information from said source node

If said first definite result is " being ", then

Receive the node of route request information and the link cost that receives between the said node of route request information itself upgrades the tolerance the said route request information through increasing, and in the routing table of the said node of reception route request information, be established to the reverse route of said source node from it; And carrying out second through the said node that receives route request information confirms; Confirm: whether the said node that a) receives route request information is said destination node; And b) in said routing table; Whether the said node that receives route request information has the effective not yet due route to said destination node, and the sequence number of this destination node is big as represented in the said route request information at least;

If said second result that confirm is for " being " in a) or " being " b), then to said source node singlecast router response message; Otherwise, propagate said route request information with the tolerance of being upgraded;

If said first definite result is " denying "; Then upgrade the said route request information tolerance, and said tolerance in the said routing table and the tolerance upgraded are compared to the promoter through increasing to receive the node of route request information and to receive link cost between the said node of route request information itself from it;

If the tolerance of being upgraded, is then upgraded said reverse route less than the tolerance in said routing table; Otherwise, then abandon this said route request information.

2. the method for claim 1, also comprise: support non-forwarding grid node, wherein said non-forwarding grid node is one of source node and destination node.

3. method as claimed in claim 2, wherein, when said non-forwarding grid node need transmit packet, said non-forwarding grid node transmitted route request information.

4. method as claimed in claim 2, wherein, only when said non-forwarding grid node was said destination node, said non-forwarding grid node was just made response to the route request message.

5. method as claimed in claim 2, wherein, if said non-forwarding grid node is not said destination node, then said non-forwarding grid node is not made response to the route request message.

6. method as claimed in claim 2, wherein, said non-forwarding grid node receives route announcement message, to learn to the promoter's of said route announcement message said route.

7. method as claimed in claim 2, wherein, said non-forwarding grid node is not transmitted the Route Selection control messages that is received to adjacent node.

8. equipment that is used for selecting through node route between source node and the destination node at wireless mesh network, said equipment comprises: be used to use MAC Address to set up the device of said route between source node and destination node; Selected route between source node and destination node is based on hybrid grid Route Selection and answer formula grid Route Selection earlier as required, wherein be used for said hybrid grid as required the device of Route Selection also comprise:

Device is used for receiving route request information through said node;

Device; Be used for through inspection originator address and message id,, carry out first by the said node that receives route request information and confirm whether once to meet this route request information before watching; Confirm whether said route request information is first route request information from said source node

Device; Be " being " if be used for said first definite result; Then receive the node of route request information and the link cost that receives between the said node of route request information itself upgrades the tolerance the said route request information, and in the routing table of the said node of reception route request information, be established to the reverse route of said source node through increasing from it;

Device; Being used for carrying out second through the said node that receives route request information confirms; Confirm: whether the said node that a) receives route request information is said destination node; And b) in said routing table, whether the said node that receives route request information has the effective not yet due route to said destination node, and the sequence number of this destination node is big as represented in the said route request information at least;

Device is if be used for said second result that confirm for a) " being " or " being " b), then to said source node singlecast router response message;

Device, if be used for said second result that confirm for a) and b) the two " denying ", then propagate said route request information with the tolerance of being upgraded;

Device; Be " denying " if be used for said first definite result; Then upgrade the said route request information tolerance, and said tolerance in the said routing table and the tolerance upgraded are compared to the promoter through increasing to receive the node of route request information and to receive link cost between the said node of route request information itself from it;

Device is if the tolerance that is used for being upgraded, is then upgraded said reverse route less than the tolerance at said routing table; Otherwise, then abandon this said route request information.

9. equipment as claimed in claim 8 also comprises: device, be used to support non-forwarding grid node, and wherein said non-forwarding grid node is one of source node and destination node.

10. equipment as claimed in claim 9, wherein, when said non-forwarding grid node need transmit packet, said non-forwarding grid node transmitted route request information.

11. equipment as claimed in claim 9, wherein, only when said non-forwarding grid node was said destination node, said non-forwarding grid node was just made response to the route request message.

12. equipment as claimed in claim 9, wherein, if said non-forwarding grid node is not said destination node, then said non-forwarding grid node is not made response to the route request message.

13. equipment as claimed in claim 9, wherein, said non-forwarding grid node receives route announcement message, to learn to the promoter's of said route announcement message said route.

14. equipment as claimed in claim 9, wherein, said non-forwarding grid node is not transmitted the Route Selection control messages that is received to adjacent node.