MANETs demand Distance Vector Routing (Ad hoc On-Demand Distance Vector Routing, AODV) is applied to the wireless mesh network (also referred to as Ad hoc wireless network) routing protocol in routing, it is possible to unicast and multicast routing. The agreement protocol is typically generated on-demand in the Ad Hoc Network Routing mode.
It is a reactive routing protocol, which means that when sending packets to the destination node, the original node before routing lookup process initiated in the network, find the appropriate route. On the contrary, many ordinary Internet routing protocols are a priori type, meaning that they are not dependent on the routing node on the path is to be contracting, but each node maintains a routing information contains the arrival of other nodes routing table. Between nodes by periodically exchanging routing information to continuously update its own routing table, in order to be able to timely reflect changes in the network topology and to maintain a consistent, timely and accurate routing information. As the name of the protocol, the MANETs demand Distance Vector routing protocol is a distance vector routing protocol plane.
In AODV, the entire network are static unless there is a demand connection is established. This means that when a network node to establish a connection to broadcast a request to establish a connection. Other AODV nodes forward the request messages and record the source node, and back to the source node of the temporary route. When a connection request receiving node to know the route to the destination node, the routing information is put as previously recorded temporary routes back to the source node back to the source node. So start using this source node to other nodes via the shortest route and has a number of hops. When the link is broken, routing error was sent back to the source node, the source node will then initiate the process of re-routing lookup.
Most complex protocol in order to ensure that the network performance and reduce the number of messages. For example, each route request will have a serial number, the node uses this number to avoid their repetition forward the route request. There is a route request "time to live" number, which will reduce the number of times they were retransmitted. There is, if after routing request fails, another route request will be twice the previous routing request message timeout after the "survival time", was sent.
There are several solutions to AODV in this regard. Another routing protocol is Dynamic Source Routing (DSR), the network routing protocol traffic fully optimized. The other is optimized link state routing protocol (OLSR) also solve the problems in this area. OLSR can continue to collect data between the nodes communicate with each other, and each node maintains a routing table optimization. So the connection can be established quickly. But OLSR is a relatively large and complex, it requires a large complex computer, a lot of memory and computing. While the frequent discovery of other network node is a huge burden. Alternatively other methods may refer to the list of wireless ad hoc network protocol.