Address Assigning Strategy And Routing Algorithm For Wireless Mesh Networks

Wireless Mesh Network(WMN) is a new type of network architecture, in which more than one links exist between neighboring nodes and the reliability of the packet delivery from the source node to the destination node is relatively high. WMN is widely used in industry, agriculture, military, health-care and more. Mesh networking is provided in IEEE 802.15.5 standard, which allocates nodes’ logical addresses such that routing is conducted without routing table and delay and energy consumption are reduced. Although the 802.15.5 standard introduced a distributed address assigning scheme, it exhibits the following shortcomings: 1) in a dynamic Mesh network, the joining/departing nodes bring with the “orphan node problem”, i.e., the new coming node is unable to join the WMN due to no available address in its parent node; and 2) the routing algorithm of IEEE 802.15.5 standard does not consider the quality of wireless link, which results in that the packets transmitted over low quality links have to be retransmitted due to packet loss, leading to high energy consumption.In the process of assigning address when forming Mesh network, the Mesh coordinator conserve an address block for the node that requests to do so for future use. However, the topology of Mesh network is random and changeable, which may cause new-coming nodes unable to join the WMN due to theirs father running out of preserved address. This is so-called “orphan node problem”. This paper intends to study the problem of address assigning scheme to cope with the orphan node problem and energy consumption of routing algorithm in IEEE 802.15.5 protocol. The main contributions are as follows:1. A two-hop neighbor address borrowing scheme is designed to solve the “Orphan Node”problem so that more nodes are allowed to join the mesh network. By changing theHello frame, the proposed scheme can improve the probability of successful joining(PSJ) of node and ratio of used addresses to total addresses and reduce the energyconsumption of borrowing process;2. Two kinds of procedure of handling a node leaving the mesh network with proposedscheme is presented. one is called active leaving and the other is called passive leaving.3. Improved Mesh routing algorithm which is more energy efficient; Compressed childrennumber report frame;Theoretical analysis and simulations are conducted to show the proposed borrowing scheme and routing algorithm outperforms the basic address assignment scheme introduced in IEEE 802.15.5 standard.