RU2486703C1 - Routing method for wireless self-organising mobile data networks - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: records in routing tables in each network node are updated by exchanging network topology information contained in service packets. Service packets which do not require fragmentation are transmitted over first layer low-speed communication channels, characterised by a first metric, and user packets are transmitted over second layer high-speed communication channels, characterised by a second metric. Network node communication update information is transmitted by first-type service packets, and after establishing a new connection with a node which is not included in the network or between two nodes belonging to different networks, information from the communication table is transmitted by second-type service packets. The lifespan of service packets depends on the network topology known to the network node, and time intervals between sending service packets are directly proportional to the total number of connections between network nodes.

EFFECT: shorter time for searching for an optimum route.

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Description

The invention relates to the field of communication and can be used to build a wireless self-organizing peer-to-peer mobile network (mobile ad hoc network - MANET) for transmitting data in the form of digital information.

A known routing method (https://datatracker.ietf.org/doc/rfc3561/), based on the establishment of a route from the sender to the addressee on demand.

A disadvantage of the known routing method is the long period of time required to establish a route, which is unacceptable in wireless data networks, the nodes of which have high mobility. In addition, the known method is not applicable in networks in which it is necessary to ensure the minimum time intervals between the passage of the first packet from the sequence of packets from the sender to the addressee, because it requires more time to pass the first packet, since at this time the route is established.

Closest to the proposed invention is a routing method (http://datatracker.ietf.org/doc/rfc3626/), we have chosen for the prototype. The method is based on the principle of proactive routing, in which each network node (hereinafter referred to as the node) collects information on the network topology in advance and determines the optimal routes to all reachable nodes. To implement this principle, the OLSR routing protocol is used, in which each node periodically sends information about the connections between nodes, and also updates the routing table entries using the information currently available on the connections between nodes.

The disadvantage of this method is the long search for the optimal route due to the possibility of its use only on single-level communication channels. In addition, the packages have a format that does not depend on the characteristics of the network equipment.

The main technical problem solved by the claimed invention is to create a routing method for wireless mobile self-organizing data networks, reducing the time to find the optimal route.

The main technical problem is achieved by the fact that in the routing method for wireless mobile self-organizing data transmission networks, which consists in updating entries in the routing tables in each of the network nodes by exchanging network topology information contained in service packets, including transmitting information over communication channels contained in user packets, from the network sending node to the network destination node, periodical broadcast by each network node in the broadcast mode of communication information, outgoing x from each node of the network, assigning them a limited lifetime, and forming from the whole set of neighboring network nodes a subset of neighboring network nodes relaying service packets, according to the proposed solution, communication channels made by two-level channels are spatially separated using the multisector structure of network nodes, and service packets that do not require fragmentation are transmitted over low-speed communication channels of the first level, characterized by the first metric, and user packets are transmitted over high-speed channels second-level ides, characterized by a second metric, moreover, information about communication updates of a network node is transmitted by service packets of the first type, and after establishing a new connection with a node 2 not included in the network or between two nodes belonging to different networks, information from the communication table is transmitted by service packets of the second type, while the service packet lifetime depends on the network topology known to the network node, and the time intervals between service packet distribution are directly proportional to the total number of connections between nodes with Networks, when relaying service packets of the first type, network nodes transmit in one sector only one copy of the service packet, which is saved by the receiving nodes, while discarding the received service packets of the first type identical to any of the available copies accepted earlier, and service packets containing a note about the need for relay.

The invention is illustrated in the figure, which shows a network diagram for implementing the inventive method.

A network for transmitting information consists of three nodes 1 of the network and a new node 2 of another network. Network nodes 1 and 2 have a spatial separation of two-level channels into four sectors, which are organized on the basis of separate sets of communication equipment. Between nodes 1 of the network, information on low-speed channels 3 is transmitted by service packets of the first type, and between nodes 1 of the network and new node 2 of another network - by low-speed channels 3, service packets of the second type.

The method is as follows.

When exchanging information about network topology between network nodes in accordance with the routing protocol, the routing tables are automatically built and records are updated in them.

Information is transmitted as part of routing protocol service packets:

- service packs of the first type “Updates of node connections”;

- service packs of the second type “Link Table”.

Service packs of the first type have a format that prescribes the following fields:

- type of package (Type = 1);

- packet relay flag (Relay);

- owner of communications (Originator);

- the number of connections (Total);

- version (Version);

- communication lifetime (TTL);

- a list of link descriptors (LinkInfo).

The number of elements in the list of link descriptors corresponds to the number of links specified in the Total field.

The link descriptor list element contains the following fields:

- neighbor identifier (Neighbor);

- The first metric of the low-speed channel (MetricSlow);

- The second metric of the high-speed channel (MetricFast).

Service packs of the second type have a format that prescribes the following fields:

- type of package (Type = 2);

- a list of tuples (Tuples).

Each tuple contains information about relationships belonging to one owner.

The list of tuples contains from one to several elements, each of which contains the following fields:

- owner of communications (Originator);

- the number of connections (Total);

- version (Version);

- communication lifetime (TTL);

- a list of link descriptors (LinkInfo).

The format of the list of tuple link descriptors is identical to the format used in the service package of the first type.

The format of service packets of the second type allows various options for the placement of information, which avoids fragmentation of packets and minimize their number, thereby eliminating additional overhead during transmission.

When determining the time interval between transmissions of service packets of the first type, the limited bandwidth of a network built on low-speed channels is taken into account and its overload is prevented. Each network node transmits service packets of the first type with information about its connections, and network nodes that receive this information transmit these service packets without waiting. The value of the “Version” field is incremented the next time the service packet of the first type is transferred with information about its relationships. When the maximum possible value of the "Version" is reached, it is reset to zero, and the process of incremental increase of the "Version" begins again. The "Version" field allows when receiving service packets of the first type to discard service packets with outdated information.

The lifetime of a service packet of the first type depends on the topology of the network known to the node at the time of its calculation and allows the service packet to reach the most distant network node, while the service packet lifetime should be as small as possible. Based on the lifetime of the service packet of the first type, the storage time of the communication information by the node is calculated.

When transmitting service packets of the first type from a network node, many nodes are determined for relaying, which includes a minimum number of neighboring network nodes. When transmitting information through them, service packets of the first type reach all nodes located at a distance of two intervals from the transmitting node. The relay of the service packet relay of the first type is set when it is transmitted in the sector of the network node in which communication with the relay node is established, and is reset if there is no communication with the relay node in the sector.

Service packets of the second type “Link Table” are transmitted after establishing a new connection with a node that is not part of the network, i.e. is a new network node, or after the establishment of communication between two nodes belonging to different networks. This reduces the time required to route user packets from new nodes to any of them.

Service packets of the second type are not relayed.

When finding the shortest route in a low-speed network, the first metric is used, which is an estimate of the communication on the low-speed channel between two nodes connected by this connection.

When finding the shortest route in a high-speed network, a second metric is used, which is an estimate of the communication on the high-speed channel between two nodes connected by this connection.

When forming each of the metrics, it is taken into account:

- node load;

- connection quality;

- direction and speed of the node.

The method can be used both for single and multi-path routing.

Claims (1)

Routing method for wireless mobile self-organizing data transmission networks, which consists in updating entries in the routing tables in each of the network nodes by exchanging network topology information contained in service packets, including transmitting information over communication channels contained in user packets from the network sending node to the network destination node, periodically broadcasting by each network node in broadcast mode information about the connections coming from each network node, assigning them a limited time I’m living, and the formation of a subset of neighboring network nodes relaying service packets from the whole set of neighboring network nodes, characterized in that the communication channels made by two-level ones are spatially separated by the multisector network structure of the network nodes, and service packets that do not require fragmentation are transmitted at low speed first-level communication channels characterized by a first metric, and user packets are transmitted via second-level high-speed communication channels characterized by a second metric, and Information on communication updates of a network node is transmitted by service packets of the first type, and after establishing a new connection with a node that is not part of the network or between two nodes belonging to different networks, information from the communication table is transmitted by service packets of the second type, while the service packet lifetime depends on the known network node network topology, and the time intervals between the distribution of service packets are directly proportional to the total number of connections between network nodes, when relaying service packets of the first type, network nodes are not edayut in one sector only one copy of the service pack, which took retain nodes, the service discards the received packets of the first type, identical to any of the available copies of earlier, and are subject to relay service packs, containing a note of the need to relay.