CN104754686B - Optimization DSDV method for routing based on vehicle-mounted short haul connection net - Google Patents

Abstract

The invention discloses an optimized DSDV routing method based on a vehicle-mounted short-distance communication network. Nodes regularly send heartbeat information including vehicle position, driving direction, etc., and update and maintain environmental information columns including related information of surrounding nodes. The method It is: the vehicle-mounted node near the first roadside node broadcasts the routing table of the node along the driving direction of the vehicle. After the vehicle-mounted node in this direction receives the routing table through the heartbeat information, it updates the routing table of the node according to the received routing table, and then sends The updated part of the routing table is broadcast along the driving direction of the vehicle; when the vehicle node near the second roadside node receives the broadcasted routing table, it first updates the routing table of the node according to the received routing table, and then sends the complete routing table to to the second roadside node. The present invention makes full use of the characteristics of the V2X network, so that the DSDV protocol can be applied to the rapidly changing V2X network.

Description

Optimal DSDV Routing Method Based on Vehicle Short Distance Communication Network

technical field

The invention relates to an optimized DSDV routing method based on a vehicle-mounted short-distance communication network, and belongs to the technical field of vehicle-mounted communication networks.

Background technique

Vehicle to X (Vehicle to X: V2X) network is the communication within the vehicle, vehicle road, workshop, outside the vehicle, and between people and vehicles through short-range communication technologies such as wireless communication, GPS/GIS, and sensors. Each node in the network is in a state of rapid movement, and its network switches frequently, so the network communication between nodes needs to use special routing discovery, establishment and maintenance methods.

DSDV (Destination Sequenced Distance VectorRouting) is a table-driven routing protocol suitable for mobile ad hoc networks. The DSDV routing algorithm saves a routing table at each node, and each entry in the table records a sequence number. An even serial number indicates the existence of the connection, which is generated by the node corresponding to the destination address. An odd serial number indicates that the connection has been broken, and is generated by the node that found the broken connection; nodes will send routing information to each other, and this routing information can be divided into two types , one contains all available routing information, and the other contains only the updated portion of the routing table. DSDV requires frequent updates of the routing table, which still consumes energy and network bandwidth when the network is idle. Once the network topology changes, a new serial number will be generated; thus standard DSDV cannot be applied to the rapidly changing V2X network.

Contents of the invention

In view of the above-mentioned reasons, the purpose of the present invention is to provide a kind of optimization DSDV routing method based on vehicle-mounted short-distance communication network, this method makes full use of the characteristic that node sends heartbeat information regularly, simplifies the routing broadcast of DSDV, can effectively reduce the management of DSDV routing protocol The consumption of information on system resources makes the DSDV protocol suitable for rapidly changing V2X networks.

To achieve the above object, the present invention adopts the following technical solutions:

Based on the optimized DSDV routing method of the vehicle-mounted short-distance communication network, the nodes regularly send heartbeat information including vehicle position, driving direction and other information, and update and maintain the environmental information column including related information of surrounding nodes. It is characterized in that the method is:

The on-vehicle nodes near the first roadside node broadcast the routing table of the node along the driving direction of the vehicle. After receiving the routing table through the heartbeat information, the on-board nodes in this direction update the routing table of the node according to the received routing table, and then update the part The routing table of the node is broadcast along the driving direction of the vehicle; when the vehicle-mounted node near the second roadside node receives the broadcast routing table, it first updates the routing table of the node according to the received routing table, and then sends the complete routing table to the second roadside node. Second road side node.

further,

The second roadside node directly sends the received routing table to the first roadside node through a high-bandwidth link, and the first roadside node sends the routing table to its nearby vehicle nodes to start the next cycle of routing table broadcasting, update process.

After the second roadside node receives the routing table, it sends the routing table to the vehicle-mounted nodes traveling in the opposite direction nearby, and each vehicle-mounted node in the opposite direction broadcasts the route to update part of the routing table until the vehicle-mounted nodes near the first roadside node Node, the on-board node sends the complete routing table to the first roadside node, and the first roadside node sends the routing table to the nearby on-board nodes, and starts the next cycle of routing table broadcasting and updating process.

When the vehicle node passes the coverage of the roadside node, it can request the roadside node to send routing table information of other road sections.

In the process of route selection, when multiple nodes are optional, the geographical location is used, and the priority is selected based on the principle of the average distance between nodes.

The advantages of the present invention are:

The optimized DSDV routing method based on the vehicle-mounted short-distance communication network of the present invention makes full use of the characteristics of nodes regularly sending heartbeat information, simplifies DSDV routing broadcasting, and can effectively reduce the consumption of system resources by the management information of the DSDV routing protocol, making the DSDV protocol It can be applied to the rapidly changing V2X network.

Description of drawings

Fig. 1 is a schematic diagram of an actual application scenario of a specific embodiment of the present invention.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings and embodiments.

In the V2X network, each node regularly broadcasts heartbeat information including vehicle location, status, IP address and other self-status information to surrounding nodes, and each node receives heartbeat information sent by other surrounding nodes at the same time. Based on the received heartbeat information, update and maintenance include: The environment information column of the surrounding node related information.

The method for optimizing the DSDV protocol disclosed by the present invention is: the vehicle-mounted node near the first roadside node broadcasts the routing table of the node along the vehicle traveling direction (from the first roadside node to the second roadside node), and the vehicle-mounted node in this direction passes through After the heartbeat information receives the routing table, update the routing table of the node according to the received routing table, and then broadcast the updated part of the routing table along the driving direction of the vehicle; when the vehicle-mounted node near the second roadside node receives the broadcasted routing table After that, first update the routing table of this node according to the received routing table, and then send the complete routing table to the second roadside node;

The second roadside node sends the routing table received directly to the first roadside node (first and second roadside nodes are adjacent) through a high-bandwidth link, and the first roadside node sends the routing table to its nearby The on-vehicle node starts the routing table broadcasting and updating process of the next cycle.

After the second roadside node receives the routing table, it may not directly send the routing table to the first roadside node, but send the routing table to the vehicle traveling in the opposite direction (the direction from the second roadside node to the first roadside node) near it. node, each on-vehicle node in the opposite direction performs route broadcasting for updating part of the routing table, until the on-board node near the first roadside node, the on-board node sends the complete routing table to the first roadside node, and the first roadside node Send the routing table to its nearby vehicle nodes, and start the next cycle of routing table broadcast and update process.

When the vehicle node passes the coverage of the roadside node, it can request the roadside node to send routing table information of other road sections.

If the heartbeat information of the adjacent node cannot be received for two consecutive heartbeat cycles, it can be inferred that the link is broken, and the metric value of the broken link is equal to ∞, and a new sequence number is assigned. In this case, the sequence number is an odd number to distinguish the sequence number allocated by the destination node for the update message.

After the above route is established, the criterion for route selection is: the sequence number is new or the metric value is small. Compare the updated information with the routing table of the node, and select the routing information with a large serial number value, so as to ensure that the routing information to the destination node is up-to-date; when the serial number values are equal, choose the best metric value (such as the minimum hop number ) routing information.

Fig. 1 is a schematic diagram of an actual application scenario of a specific embodiment of the present invention. As shown in the figure, RS1 and RS2 are roadside nodes deployed at two adjacent intersections, and V1-V7 are vehicle-mounted nodes on the road between the two roadside nodes;

The vehicle-mounted node V7 near the roadside node RS1 broadcasts the routing table of this node. Since V7 can receive the heartbeat information of nodes V6 and V5, the routing table broadcast by V7 includes the information of V6 and V5.

V6 can receive the heartbeat information of V7, V5, and V4. V6 senses the existence of these two nodes through the heartbeat information of V7 and V5. Therefore, when V6 broadcasts the routing table, it only broadcasts the information of node V4 that V7 cannot perceive. After the V7 node receives the routing information broadcast by V6, it adds the V4 route in its own routing table. The V5 node senses the existence of these three nodes through the heartbeat information of V7, V6, and V4, so it only broadcasts the routing information of the V3 node that the V6, V7 nodes cannot feel. Add the information of V3 nodes to the respective routing tables.

In the process of route selection, when multiple nodes are optional, the geographical location is used, and the priority is selected based on the principle of the average distance between nodes. For example, there is a hop between node V6 and node V3. You can choose node V5 or node V4 for the first hop. According to the above-mentioned principle of average distance between nodes according to geographical location, choose node V4 as the next hop node.

After node V1 establishes its own node routing table, when node V1 passes roadside node RS2, V1 sends its own node routing table to roadside node RS2, and RS2 transmits the routing table to RS1 through the high-bandwidth network connected to the roadside node , and then RS1 transmits to node V7, starts V7 to initiate the second round of routing broadcast, V7 will broadcast the routing information of V2 and V1 nodes that do not exist in itself, and add it to its own routing table, similarly, V6, V5, V4 will also increase the routing table of its own node.

The above are the preferred embodiments of the present invention and the technical principles used therefor. For those skilled in the art, without departing from the spirit and scope of the present invention, any technical solution based on the present invention Obvious changes such as equivalent transformation and simple replacement all fall within the protection scope of the present invention.

Claims (2)

1. Based on the optimized DSDV routing method of the vehicle-mounted short-distance communication network, the heartbeat information including vehicle position and driving direction is regularly sent between nodes, and the environment information column including the relevant information of surrounding nodes is updated and maintained. It is characterized in that the method is: The on-vehicle nodes near the first roadside node broadcast the routing table of the node along the driving direction of the vehicle. After receiving the routing table through the heartbeat information, the on-board nodes in this direction update the routing table of the node according to the received routing table, and then update the part The routing table is broadcast along the direction of vehicle travel; When the vehicle-mounted node near the second roadside node receives the broadcasted routing table, it first updates the routing table of the node according to the received routing table, and then sends the complete routing table to the second roadside node, wherein the second roadside node The side node directly sends the received routing table to the first roadside node through a high-bandwidth link, and the first roadside node sends the routing table to its nearby vehicle nodes to start the next cycle of routing table broadcasting and updating process. Among them, after the second roadside node receives the routing table, it sends the routing table to the vehicle-mounted nodes driving in the opposite direction nearby, and each vehicle-mounted node in the opposite direction broadcasts the routing table to update part of the routing table until the route near the first roadside node The vehicle-mounted node, the vehicle-mounted node sends the complete routing table to the first roadside node, and the first roadside node sends the routing table to its nearby vehicle-mounted nodes, and starts the routing table broadcasting and updating process of the next cycle; Among them, when the vehicle node passes the coverage area of the roadside node, it can apply for the roadside node to send the routing table information of other road sections; If the heartbeat information of the adjacent node cannot be received for two consecutive heartbeat periods, the link is broken, and a new sequence number is reassigned to the link, and the routing selection criterion is: the sequence number is new or the metric value is small. 2. the optimized DSDV routing method based on the vehicle-mounted short-distance communication network as claimed in claim 1, is characterized in that, in routing selection process, for the optional situation of a plurality of nodes, utilize geographical position, with the average distance between nodes Prioritize for principles.