JP4939579B2 - Route selection in wireless networks - Google Patents

Description

  The present invention relates to a wireless network, and more particularly to a wireless mesh network. More particularly, the present invention relates to processing route request messages in an on-demand route selection protocol.

  On-demand route selection protocols, such as the Ad Hoc On-demand Distance Vector (AODV) route selection protocol defined by the IETF MANET Working Group, use route request and route response mechanisms, and wireless Establish a path between two nodes in a mesh / ad hoc network. When the source node wants to transmit a data packet / frame to the destination node, if the source node does not have a valid route to the destination node and needs the valid route, the source node sends a route request (RREQ, Route Request) message is sent through the network to find the route to the destination. The reverse path back to the source is created by the nodes in the network when they receive and forward the RREQ. When the node receives the RREQ, (1) the receiving node itself is the destination, or (2) the receiving node has a valid route to the destination and the “destination only” and “D” flags of the RREQ are false. The receiving node responds to this request by generating a Route Reply (RREP) message. The RREP is forwarded to the source node by unicast over the established reverse path. In this way, the forward path to the destination is created at the intermediate node and finally at the transmission source node. An established path expires when it is not used within a given path lifetime.

  In AODV, the “destination only” flag of the RREQ message is set by the source node and is not changed by the intermediate node. If the RREQ “destination only” flag is set by the source node, the intermediate node will not respond to the RREQ with an RREP message, even if the intermediate / receiving node has a valid path to the destination node. The intermediate node forwards / resends the RREQ to its neighbors. The destination node only responds to this RREQ. In this mode of operation, the most recent optimal route between the source node and the destination node is eventually discovered during processing, but the route discovery latency can be long. Short latency is very important for real-time applications such as voice and video communications.

  If the “destination only” flag is not set by the source node, any intermediate node that has a valid path to the destination node will respond to the RREQ with a RREP message. The RREP message is sent back to the source node by unicast to establish a forward path to the destination node. If the “free RREP” (“G”) flag in the RREQ is set, this intermediate node unicasts the free RREP to the destination node. Therefore, the destination node learns the route to the source node. However, in AODV, if the intermediate node generates an RREP (because the intermediate node has a valid path to the destination node), the intermediate node discards the RREQ. In this approach, the source node does not have to wait for the destination node's response, so the source node can find the route to the destination node more quickly. However, the best end-to-end route may not be discovered because the route cached at the intermediate node may not be the best route to the destination node. Since the metric can be changed by the dynamics of the wireless network, the cached path becomes worthless. In other words, due to changes in network topology, route metrics, etc., the route cached on the intermediate node will be degraded, or other routes with better end-to-end metrics will be available and make other routes more valuable Can be something.

  The problem solved by the present invention is a method of quickly finding the best path between a source node and one or more destination nodes using RREQ and RREP mechanisms.

  The present invention processes / forwards route request (RREQ) messages and creates route response (RREP) messages in an on-demand protocol, eg, AODV, thereby creating significant route discovery delay / latency in wireless mesh / ad hoc networks. Disclosed are methods and systems in which the best path can be found without causing In particular, when the source node wants to find a route to the destination node, the source node specifies the destination node in the destination list, initializes the metric field to 0, and distributes the RREQ message to the network. The RREQ message has a new flag “intermediate response (IR)” for each destination node. When the transmission source node starts distributing the RREQ, the transmission source node sets a flag corresponding to the destination node in the RREQ message in order to find a route to the destination node. While distributing the RREQ, the first intermediate node that has a valid path to the destination node responds to the RREQ message with an RREP message. The RREP message is sent unicast to the source node, thereby quickly establishing a temporary forward path to the destination. Thus, the source node can use this temporary forward path and transmit data packets / frames with a short path discovery delay / latency. The first intermediate node B resets / clears the “IR” flag in the RREQ message and forwards the updated RREQ message downstream towards the destination node. Since the “IR” flag of the RREQ is reset, the downstream intermediate node does not respond to the RREQ, but only propagates, even if the downstream intermediate node has a valid path to the destination node. The RREQ finally arrives at the destination node. The destination node may select the best route / path based on end-to-end metrics, send a new RREP to the source node, and establish the best route between the source node and the destination node . If the best route is different from the temporary forward route established via RREP from the intermediate node, the source node switches the best route when the best route is established.

  A system and method are described, wherein the system and method discovers a route between a source node and a destination node in a wireless network and sets an intermediate response flag in a route request message by the source node; Disseminating the route request message to a wireless network; responding to the route request message with a route response message by a first intermediate node having a valid route to the destination node. The system and method then updates the route request message; and redistributes the route request message to the wireless network. The responding step results in establishing a temporary forward path between the source node and the destination node of the wireless network. Also described is a system and method for finding the best route when the route response message becomes the first route response message. The system and method for discovering the best route includes determining a best route between the destination node and the source node by the destination node based on a cumulative metric received in a route request message received by the destination node. Selecting; further creating a further route response message; and unicasting the further route response message to the source node. If the temporary forward route is the best route, the further route response message acts as a confirmation, and if the temporary forward route is not the best route, the further route response message is the source node. The further route response message functions to establish the best route.

  The invention will be understood by reading the following detailed description in conjunction with the figures.

It is an example of a RREQ message format. 1 is a schematic diagram of a wireless mesh network according to the principles of the present invention. FIG. 1 is a schematic diagram of a wireless mesh network according to the principles of the present invention. FIG. It is a flowchart of the on-demand type | mold route selection protocol which shows the case where this invention is used. 3 is a flowchart of the method of the present invention. FIG. 2 is a block diagram of a node according to the principles of the present invention.

  A source node / mesh point examines its route selection table path when it wants to transmit a data packet / frame to a specific destination node. If there is a valid path, the source node / mesh point transmits the data packet / frame to the destination node for the next hop specified in the path selection table. If no valid route exists, the source node initiates route discovery by sending a route request (RREQ) message over the wireless mesh / ad hoc network. Data packets / frames may be generated within / by the node or from a station associated with the node if the node is a wireless access point. In some cases, the source node needs to find routes / paths to multiple destination nodes. The source node may distribute an RREQ for each destination or reduce the routing overhead and stream a single RREQ message embedded in the network with a list containing multiple destination node addresses.

  FIG. 1 is an example of another possible type of RREQ message format. The RREQ message includes, for example, a source / source node address, a source sequence number, a destination node address, and a destination sequence number (or a list of destination numbers and destination addresses and their sequence numbers), an RREQ ID, Has message ID, message length, time to live (TTL), number of hops, route selection metric, flags, and other information. In addition to the flags “destination only” (“D”) and “free RREP” (“G”), a new flag, referred to herein as an “intermediate response” (IR) flag, is included in the RREQ message. The “D” and “G” flags are transmitted as in conventional AODV. These two flags are not set / used by the source node and are ignored by the intermediate node and the destination node. In one alternative embodiment, the RREQ message does not include any “D” and “G” flags. When the RREQ message conveys a list of destination addresses, a plurality of “intermediate response” flags corresponding to the destination addresses are included in the RREQ message. When the source node wants to find a route to one or a plurality of destination addresses, it sets an “intermediate response” (IR) flag corresponding to the destination address. It should be noted that the destination node address can be an Internet Protocol (IP) address or a second layer (medium access control, MAC) address. In order to adapt to changes in network conditions and to maintain the best metric path between the nodes, each of the active source nodes optionally has periodic RREQ messages (maintenance RREQ) in the wireless mesh / ad hoc network. ) May be sent to the destination address of the communication partner. The “IR” flag in the maintenance RREQ is not set. The intermediate node and the destination node process the maintenance RREQ according to the same rules used to process the non-maintenance RREQ at the discovery stage.

  Thus, it can be seen that as a result of the dissemination of non-maintenance and maintenance RREQ messages in the wireless mesh network, a reverse path to the RREQ generator (source node) is established / updated at the intermediate node and the destination node. The distribution of unmaintained RREQ messages also causes RREQ messages from the destination node and possibly intermediate nodes. The distribution of the maintenance RREQ message causes the RREQ message from the destination node.

  When an intermediate node or destination node receives an RREQ message, if the RREQ message passes a path / path that provides a better metric than the current reverse path to the source node, the RREQ message is a reverse path to the destination node. Or update its current reverse path. It should be noted that each node receives multiple copies of the same RREQ message (occurring at the same source node and having the same RREQ ID), and each RREQ message is received / intermediate / destination from the source node. To go through different paths to the node. The RREQ message is forwarded (retransmitted) if the reverse path is created or changed, or if it is a “first copy” of the RREQ message. “First Duplicate” means herein that the duplicate of the RREQ message is the first duplicate or that the receiving / intermediate / destination node is identified by the source address and RREQ ID of the particular RREQ message Means that the first RREQ message is received or viewed. When an intermediate node forwards an RREQ message, the RREQ message metric field is updated to reflect the cumulative metric of the path from the intermediate node to the source node of the RREQ. Furthermore, if the “IR” flag for the destination node of the destination node included in the list of destination nodes of the received RREQ message is set and the intermediate node has a valid path to the destination node, the intermediate node routes to the RREQ message. Respond with a reply RREP message. This route response message is transmitted to the source node by unicast to establish a forward route to the destination node. The source node then uses this path to immediately send the data frame / packet to the destination node. If an intermediate node responds to an RREQ message with an RREP message to a destination node in the RREQ destination node list, the “IR” for that destination node in the RREP message before resending the updated RREP message to the network Reset / clear flag. The reason that the “IR” flag is reset after the RREP message is sent is to suppress any RREP message from the downstream intermediate node. The first intermediate node that has a valid route to the destination node along the route transmitted by the distribution of the RREQ message responds to the destination node with an RREP message. If the “IR” flag for the destination in the RREQ message is reset / cleared, the intermediate node should not respond with an RREP message even if it has a valid path to the destination node.

  After creating / establishing a reverse path to the source node, the destination node returns a unicast RREP message to the source node. When the intermediate node receives the RREP message, it creates a forward path to the destination node and forwards the RREP message toward the source node. When the source node receives the RREP message, it generates a forward path to the destination node. If the destination node receives a further RREQ message with a better metric, the destination node updates its route to the source node with a new route, and sends a new RREP message along the updated route to the source Return to node. The new RREP message establishes a better (updated) forward path from the source node to the destination node at the intermediate node and finally at the source node. Once this better forward path is established, the source node uses the path to transmit data. Finally, a bi-directional, best end-to-end metric path is established between the source node and the destination node. When this method is used, an intermediate node having a valid route to the destination node responds to the RREP message, and the source node can quickly obtain a route to the destination node established by the RREP message. If the route is not the best end-to-end metric route between the source node and the destination node, the route is later updated to the best route.

  Please refer to FIG. FIG. 2 illustrates the dissemination of a route request (RREQ) message in a wireless mesh / ad hoc network. Intermediate node B that has a valid path to destination node E responds to the RREP message with an RREP message. As an example, consider the case where source node A attempts to find a route to destination node E. Source node A disseminates a route request (RREQ) message with an “IR” flag set in the wireless mesh / ad hoc network. The intermediate node B already has an effective path B-C-D-E to the destination node E. When the intermediate node B receives the RREQ, the intermediate node B generates a reverse path to the transmission source node. From the source node, the intermediate node B receives the RREQ as the next hop (source node A) of the reverse path / path. Since intermediate node B has a valid path to destination node E and the RIR “IR” flag is set, intermediate node B responds to RREQ with a unicast RREP. RREP establishes a forward path in source node A to destination node E. As soon as the source node A generates a path / path to the destination node E by RREP from the intermediate node B, the source node A sends the data packet / to the destination node E via the path A-B-C-D-E. You can start sending frames. Intermediate Node B resets the “IR” flag in the RREQ message and forwards the message further. The reason for resetting the “IR” flag is to limit responses to RREQs that are distributed only to the first intermediate node that has a valid path to the destination node. Other intermediate nodes downstream, eg C and D, do not need to respond to this RREQ by RREP because the “IR” flag is not set. Assume that intermediate nodes F, G, and H do not have a valid path to destination node E. When the intermediate nodes F, G, and H receive the distributed RREQ message, they generate a reverse path to the source node A. From source node A, each of intermediate nodes F, G, and H receives RREQ as the next hop in the reverse path. Each of the intermediate nodes F, G, and H then forwards further RREQ messages.

  In this example, the destination node E receives two copies of this RREQ that carry different paths A-B-C-D-E and A-F-G-H-E. Assuming that two RREQs arrive at the destination node E in the order A-B-C-D-E and A-F-F-G-E, the destination node E first has the intermediate node E route the RREQ to the path / path. As soon as it is received by A-B-C-D-E, a route to the source node A passing through the intermediate node D is created. At this time, reverse paths to the source node A are established in the intermediate nodes B, C, and D. The destination node E transmits RREP along the route E-D-C-B-A. RREP only refreshes the path A-B-C-D-E. If there is some other destination node in the RREQ destination list, for example node I, destination node E deletes itself from the destination list and forwards the RREQ further (eg to node I). If there are no other destination nodes in the RREQ destination list, the RREQ is not forwarded.

  Referring to FIG. 3, a wireless local area mesh network is shown, where destination node E (1) returns RREP upon receipt of RREQ through ABCDE, and (2) new Send RREP and establish better forward path / path after receiving RREQ through A-F-G-H-E. When the destination node E receives an incoming RREQ along A-F-G-H-E, the destination node E has a better metric than the current forward path / path A-B-C-D-E. Determine that it has arrived along the path to A. Accordingly, destination node E changes / updates the next hop from intermediate node D to intermediate node H and updates the metric. Destination node E then returns a unicast RREP to source node A through intermediate node H and updates and forwards the RREQ if one or more other destination nodes exist in the RREQ destination list. RREP establishes a route to source node A via intermediate nodes H, G, and F. When the source node A receives the RREP, the source node A changes / updates the next hop from the intermediate node B to the intermediate node F. The route to the destination node E is changed to A-F-G-H-E.

  Referring to FIG. 4, a flowchart for processing an RREQ message is shown. When a node receives a RREQ message, it first creates / establishes or updates a reverse path to the previous hop from which the node received the RREQ message, as needed, 410. The intermediate / receiving node may then generate or update the reverse path to the RREQ generator as follows. At 415 and 420, if the reverse route to the source of the RREQ message does not exist in the route selection table or is invalid, the reverse route is generated or updated. The next hop in the routing table for the reverse route to the RREQ generator will be the previous hop (RREQ message received from this node). If there is a valid reverse path to the RREQ source, then at 425, the source sequence number in the RREQ message is compared with the sequence number of the path entry in the reverse path path selection table. If the sequence number in the RREQ message is old, the sequence number is removed at 445 and further processing is performed. Otherwise, at 430, if the new metric is better than the metric of the current route to the origin in the route selection table, the current reverse path to the origin is changed. The new metric is determined by adding the link metric between the node that transmitted the RREQ message and the node that received the RREQ message to the metric in the RREQ message. If the new metric is better than the current reverse path metric in the routing table, but at 435, the source sequence number in the RREQ is greater (newer) than the sequence number in the reverse path routing table 450 The intermediate node checks whether the mesh network supports arbitrary history processing and the best route candidate cache function. If these arbitrary processing functions are not supported, the reverse path to the RREQ generator is updated at 455. When a reverse route is created or changed, the sequence number in the route selection table of the reverse route is set to the source sequence number in the RREQ message, the next hop becomes the node that sent the RREQ message, and the metric Is set to a new metric, and the hop count is set one more than the hop count in the RREQ message.

  If a reverse path to the source node is created or changed at 420 and 440, or if the RREQ message is the first duplicate of a new RREQ message (no previous RREQ ID from source) 475 The RREQ transfer and RREP generation routine described in this specification is executed. In other cases, the RREQ transfer and RREP generation routines described herein may be executed by the node. For example, in certain best route candidate caching methods, RREQ messages may be stored in a queue with a timer while caching route candidates. When the queue timer expires, the RREQ transfer and RREP generation routine is executed.

  The source node may send a periodic maintenance RREQ message to refresh its active forward and reverse paths. Each time the source sends a maintenance RREQ message, the route refresh period is invoked. In some cases, a node that already has the best reverse path to the source node has a new sequence number but the worst metric path to the source node before receiving the RREQ message through the current best metric path. RREQ message with is received. In addition, copies of RREQ messages propagated along the current best metric path may be lost during distribution. These events can cause route flapping. In order to reduce route flapping and select the best route during each route refresh period, some sort of history and best route candidate cache mechanism may be used. If it is determined at 460 that the history and best route candidate cache option is implemented in the mesh network, the intermediate node updates the route selection table and the source sequence number in the RREQ message is the sequence in the route selection table. If the number is larger (newer), the reverse path is changed by a value larger than the threshold. Otherwise, at 465, the reverse route is cached as a potential alternative route candidate.

  If the node then learns that the current reverse path is degraded and worse than the reverse path candidate, it can change to a path candidate learned earlier within the same refresh period. The present invention has described a method and system for forwarding RREQ messages and generating RREP messages to find the best route in a wireless mesh network without long route discovery delay / latency. The method of the present invention operates with or without history and candidate / alternate path caches.

  Referring to FIG. 5, a flowchart of the RREQ transfer and RREP generation method of the present invention is shown. At 505, the node determines whether the node is a destination node, that is, whether one or more addresses (self_addr) of the node matches the requested destination address rreq.dest in the destination list of the RREQ message. . It should be noted that a node itself may have multiple addresses, or a node may be a proxy for another node. For example, a node is an access point and may generate / manage routing messages instead of the traditional station associated with that node (the proxy for that station). The function in this case is similar to the situation where a node has multiple addresses. The destination address of the associated station may be treated as an access point alias address. If one or more addresses specified in the destination list of the RREQ message belong to the node, or if one of the nodes uses the node as a proxy, the node is a destination node. In the RREQ message, the destination node is a node proxied by a certain node, and when the node receives the RREQ message, the node sends the RREQ message as if the destination node address is the address of the node itself. May be processed. Further, the node may be a destination node for a request address in the destination list of the RREQ message, but may be an intermediate node for another request address in the destination list of the RREQ message. If the node's address or addresses match the requested destination address in the RREQ message destination list, at 510, the node generates a unicast RREP message and to the originator of the RREQ message for these matched destination addresses. Send. At 515, the destination node deletes its address / proxy address from the destination list of the RREQ message. Thereafter, at 520, if no request address remains in the destination list of the RREQ message, at 525, the RREQ message is discarded. If the node is not the destination node for any request address in the RREQ message destination list, or if there is no other request address in the RREQ message destination list other than the address of the node, that is, the node is the RREQ message. If it is an intermediate node for one or more addresses in the destination list, the node checks the remaining addresses in the destination list of the RREQ message as follows. Assume that rreq.dest [i] represents the (i + 1) th address in the destination list of the RREQ message. At 545, the node initializes an index (eg, i) and at 550 examines rreq.dest [i], the first address in the destination list of the RREQ message, represented by rreq.dest [i]. Determine if there is an active forward path to the destination node. If the intermediate node has an active route to the destination, the route to the destination node is valid (555) and has at least the same size as the sequence number indicated in the original RREQ message (560) (IR) "flag is set (570), and at 575, the intermediate node generates an RREP message to this requested destination address, and unicasts the generated RREP message to the source of the RREQ message along the current reverse path. To send. At 580, the “IR” flag for this request destination in the RREQ message is reset. At 590, the node increments the index (eg, by 1) to see if there are more addresses in the destination list of the RREQ message. If there are additional addresses in the destination list of the RREQ message, the above loop starting at 550 is repeated. That is, if the RREP message needs to be sent to the next request destination, the loop is repeated. The loop is repeated until all addresses in the RREP message destination list have been examined.

  At 530, the original incoming RREQ message is examined to determine if the time to live (TTL) value is greater than one. At 535, if the TTL value is greater than 1, the information in the original RREQ message is updated and the TTL value in the outgoing RREQ message is decreased, for example, by one. At 535, the source sequence number, metric and hop count are set to the corresponding information in the updated route entry for the source. At 540, the updated RREQ message is forwarded.

  It should be noted that the destination node may process / proxy one or more addresses and the intermediate node may have a valid path to one or more destination addresses. The RREQ message may carry one or more destination addresses in its own destination address list. The processing / intermediate / destination node may satisfy the above condition and send an RREP message to multiple request addresses in the destination list of the RREQ message. When transmitting a RREP message to a plurality of destinations, the node may transmit a plurality of RREP messages, one message for each destination. Alternatively, the node may send a single aggregated RREP message with multiple addresses in the address list.

  FIG. 6 is a block diagram illustrating in detail the node 600 of the present invention. The node includes a connection quality and load measurement module 605, a path metric calculation module 610, a path selection module 615, and a communication module 620. The connection quality and load measurement module 605 measures connection / channel quality and load to each of its neighbors. The connection quality and load measurement module 605 provides the measurement result to the path metric calculation module 610. Thereby, the path metric calculation module 610 may determine the connection cost / metric to each of its neighbors. It should be noted that a node may have multiple neighbors, multiple wireless interfaces, and multiple physical / logical channels / connections. All of them need to be measured. The path metric calculation module 615 of each node calculates the path metric of each node with which the node communicates using the measurement result and other information generated by the connection quality and load measurement module. The route metric is updated periodically. The route selection module 615 determines the route / path and forwards / communicates data to the destination node based on the calculated route metric. The route selection module 615 exchanges route selection control messages and data with other nodes in the mesh network via the communication module 620. It should be noted that a node may have one or more wireless communication interfaces and other communication interfaces. It should be understood that the routing module may actually have some smaller units or may be combined with other modules described herein. It should be further understood that (especially in connection with FIGS. 3 and 4) the software, hardware, firmware, or the process described herein is performed within or by the routing module, or Any combination of these may be used.

  It should be understood that the present invention can be implemented in various forms of hardware, software, firmware, special purpose processors, or combinations thereof, such as in a mobile terminal, access point, or cellular network. is there. Preferably, the present invention is implemented as a combination of hardware and software. Further, the software is preferably implemented as an application program that is explicitly incorporated into the program storage device. The application program can be uploaded and executed on a machine having any suitable architecture. Preferably, the machine is implemented on a computer platform having hardware such as one or more central processing units (CPUs), a random access memory (RAM), and input / output (I / O) interfaces. The computer platform also has an operating system and microinstruction code. The various processes and functions described herein can either be part of the microinstruction code or part of the application program (or any combination thereof) that can be executed via the operating system. In addition, various other peripheral devices may be connected to the computer platform such as an additional data storage device and a printing device.

  It should be further understood that some of the components that make up the system and the method steps shown in the drawings are preferably implemented in software and the actual connections between the system components (or between processing steps). Can vary depending on how the invention is programmed. With the teachings herein, one of ordinary skill in the art will be able to perform these and similar implementations or settings of the invention.

Claims (14)

Discovering an effective route between a source node and a destination node in a wireless network , wherein a first intermediate node having the effective route receives the route request based on a state of an intermediate response flag in a route request message Responding to messages ;
Establishing a communication between the source node and the destination node by using the valid path;
The transmission is a step of finding a better route between the source node and the destination node, the better path, step based on the end-to-end metrics; the sender using and the better route Establishing communication between a node and the destination node;
Having a method. Said transmitting the better path between the source node and the destination node, the destination node by selected based on end-to-end metrics, process of claim 1.   Establishing communication between the source node and the destination node using the effective path comprises:
  Receiving a response to the route request message from the first intermediate node; and
  Establishing a temporary path between the source node and the destination node based on the response;
  The method of claim 1, comprising: Discovering the effective path between the source node and the destination node comprises:
Step of setting said intermediate reply flag of the route request message by the source node;
Transferring the route request message through the wireless network ;
In response to the route request message from said first intermediate node having a valid route to the destination node, step receives the route reply message; and
Establishing a temporary path between the source node and the destination node based on the response;
The method of claim 1, comprising : Transferring a maintenance route request message to the wireless network;
Was further Yes,
The forwarding step comprises disseminating the maintenance route request message to the wireless network in order to maintain a best route between the source node and the destination node and to adapt to changes in wireless network conditions. In addition,
The method of claim 4, wherein the best path is based on an end-to-end metric. Receiving a response to the maintenance route request message as if it were the route request message;
6. The method of claim 5, further comprising: The method according to any one of claims 4 to 6, wherein the route is a best route and the route response message is a first route response message. A means for finding an effective route between a source node and a destination node in a wireless network , wherein a first intermediate node having the effective route receives the route request based on a state of an intermediate response flag in a route request message. Means to respond to the message ;
It means for establishing a communication between the source node and the destination node by using the valid path;
The transmission is a means for finding a better route between the source node and the destination node, the better path, means based on the end-to-end metrics; the sender using and the better route Means for establishing communication between a node and said destination node;
Having a device. It said transmitting the better path between the source node and the destination node, the destination node by selected based on end-to-end metrics, according to claim 8.   Means for establishing communication between the source node and the destination node using the effective path;
  Means for receiving a response to the route request message from the first intermediate node; and
  Means for establishing a temporary path between the source node and the destination node based on the response;
  9. The apparatus of claim 8, comprising: Means for discovering the effective path between the source node and the destination node;
It means for setting the intermediate reply flag of the route request message by the source node;
Means for transferring the route request message via the wireless network ;
In response to the route request message from said first intermediate node having a valid route to the destination node, means for receiving a route response message; and
Means for establishing a temporary path between the source node and the destination node based on the response;
9. The apparatus of claim 8, comprising: Means for transferring a maintenance route request message to the wireless network;
Was further Yes,
The means for forwarding comprises means for disseminating the maintenance route request message to the wireless network in order to maintain a best route between the source node and the destination node and to adapt to changes in wireless network conditions; In addition,
The apparatus of claim 11, wherein the best path is based on an end-to-end metric. Means for receiving a response to the maintenance route request message as if it were the route request message;
The apparatus of claim 12, further comprising: The apparatus according to claim 11, wherein the effective route is a best route, and the route response message is a first route response message.

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