How to optimize the use of the Routing Protocol

As one of the most important protocols in wireless networks, the routing protocol of the same type of network is greatly improved in wireless sensor networks and self-organizing networks. This article will focus on some improvements in use. We hope that this will help you and provide some understanding reference.

Although the Protocol has a routing maintenance mechanism, due to node mobility, sometimes the routing repair fails. In this case, the upstream node can only re-run the routing discovery process to the source node to complete the communication between nodes ｡

In the process of rebuilding a route for the source node, because of the routing discovery method, flood mode, and Protocol principle, the routing is established, because the TTL value of the source node cannot directly reach the target node in most cases, you need to re-run the route discovery process and continuously run the process until the destination node location is finally found ｡

The routing latency and overhead rate will be greatly increased when the routing discovery process is run again and again. Therefore, the researchers have proposed the technology for backing up routing and use the traditional circuit switching network and grouping network ideas for reference, multiple paths are provided to the source node to reach the target node. Therefore, when the main route is interrupted, nodes can use other Backup Paths to communicate. Typical backup routing technologies include AODV-BR and AODV-ZHBR ｡

After carefully analyzing and studying the backup routing technology, this paper proposes an improved method to construct a backup routing by using the improved hello message of timed transmission, when the primary route is disconnected, the data packet can arrive at the destination from the path provided by the backup route, reducing the packet loss rate and latency ｡

The new protocol is based on the addition of the Hello message function. In the classical put-in-line routing protocol, the function of the Hello message in the put-in-line routing protocol is to detect the interruption of the activation link, it forms the connectivity Management Mechanism of the routing protocol ｡

This mechanism maintains a list of nodes that are adjacent to each other and are in communication status, this list is called the neighbor list. If no data is sent to nodes that are in communication for a period of time, the system actively broadcasts Hello messages to notify neighboring nodes of their own existence within the scope of their direct communication. The nodes that receive the message extend the survival time of the neighboring nodes. If it comes from a new neighboring node, add a record to the neighbor list. The Node periodically checks the validity of the adjacent node. If the node times out, the node is considered to have left the original position ｡

This article proposes a new method. When the interval ends to the time when the Hello message is to be sent, the node first looks for the route option with the longest lifetime from its route table, add the route Destination Address in the route entry of the route entry to the Hello message, so that the Hello message contains an accessible route contained by the sending node, after the neighbor node receives the Hello message, it finds its route table. If no route entry exists, it is added to its route table. The reachable address of the route entry is the reachable route contained by the sending node, the next hop address is the sending node. If this route entry exists, it is updated according to the condition. The Routing backup process from A to E is shown in 1 ｡

Figure 1backup route generated by Hello Message

When the current valid path is interrupted, the node sends a broadcast group with 1 hops during route resolution, this broadcast group has a special flag marking it as the main route to interrupt the broadcast. Then it starts to repair the routing corruption mechanism. When the surrounding nodes receive such a broadcast group, if your route table contains a destination route entry in the group, the route entry is forwarded to the group. If no route entry exists, ignore the route entry generated by the Hello message, A neighbor node may have a route entry to the destination around the disconnected node. Therefore, the broadcast group will be resolved after it is sent, without delay. The routing protocol of the OCTA 7 protocol is followed by the repair of the route corruption mechanism, because of the existence of backup routes, the damaged routes are repaired, and the subsequent groups can reach the destination smoothly. When Node B moves, the links of Node B and node C are interrupted, the routing process 2 that re-generates to E after route repair is shown in ｡

Figure 2 data transmission and restoration using backup routes