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imized Link State Routing Protocol (OLSR).
Message Size - The size of this message, including message header, counted in bytes.
Originator Address – Originator Address is the main address of the originator of this message.
Time To Live - The maximum number of hops this message can be forwarded. Using this field one can control the radius of flooding.
Hop Count - The number of times the message has been forwarded.
Message Sequence Number - A sequence number incremented by one each time a new OLSR packet is transmitted by this host.

3.3.2 Message types

The core functionality of OLSR defines three message types, which will all be described in detail later. All core functionality of OLSR is based on processing and generation of these messages. However, the OLSR protocol packet format allows for a wide variety of custom packets to be transmitted and flooded to the needs of the designer. OLSR will forward unknown packet types according to the default forwarding rule as explained later. The MPR optimization used in OLSR makes this possibility for message flooding a great asset to anyone in need of net-wide broadcasting of traffic in the ad-hoc network.

26. Hipercom Project: T. Clause and, P.Jacquet.”Optimized Link State Routing Protocol (OLSR).

3.4 Multipoint Relaying:

OLSR uses flooding of packets to circulate topology information throughout the network. All nodes retransmit received packets in the flooding, in its simplest form. In order to avoid the loops, a sequence number is normally carried in those packets. The receiving node then registers the sequence number to make sure that a packet is only retransmitted once. The packet will not be retransmitted, if a node receives a packet that have the sequence number lower or equal to the last registered retransmitted packet from the sender.

Other methods are added on the wired network such as there will be no retransmission on the interface on which the packet is already arrived whereas on the wire less multi hop network, node must have to retransmit packet on the interface on which it has arrived since this is the very nature of wireless multi-hop networks. .

This whole process again causes each re-transmitter to receive a duplicate packet from every symmetric neighbor which again transmits that packet.

The Wireless flooding structure is shown in figures: 3-2a

3.4.1 Multipoint relaying

The concept of multipoint relaying (MPR) is to reduce the number of duplicate retransmissions while forwarding a broadcast packet. MPR limitizes set of nodes retransmitting a packet from all nodes to a subset of all nodes. Size of the subset is depending upon the topology of the network.

Restriction of retransmission of a packet is gained by making neighbors to act as Multipoint relays (MPRs). Set of MPRs is calculated by every node itself so that all Two Hop neighbors are reached through one MPR. This means that for every node n in the network that can be reached from the local node by at minimum two symmetric hops, there must exist a MPR m so that n has a symmetric link to m and m is a symmetric neighbor of the local node. The scenario shown in figure 3-5, the black node will be selected by Node as MPRs. All the nodes will be reached through MPR in that way. The retransmission of the traffic from node “a” will not本论文由英语论文网提供整理，提供论文代写，英语论文代写，代写论文，代写英语论文，代写留学生论文，代写英文论文，留学生论文代写相关核心关键词搜索。