Research On Load Balancing Scheme In Ieee802.11s Wireless Mesh Network

Wireless Mesh network, one of the key technologies of the"last mile"broadband access problem, is a multi-hop, high-speed, and high-capacity wireless network, which combines the characteristics of wireless LAN and Ad hoc networks. As a distributed network, how to carry out the distribution of tasks dynamically among multiple nodes is significant for the performance of the network. Currently, a couple of technologies are developed, but still many challenges exist in throughput and resources allocation, so it is worthy further study in this field.Due to the specificity of nodes and the networking in wireless mesh network, its load-balancing strategy is different from the traditional wireless LAN or Ad hoc Network. In this paper, the layered load balancing concept of the wireless Mesh network is proposed for the hierarchical characteristics of the wireless Mesh network.Firstly, the conception, load balancing causes and status quo of wireless mesh network are introduced briefly in this paper; then,through the comparison of different algorithms and protocols, the requirements of terminal access algorithm and load balancing routing protocol are derived. Secondly, LBAA (Load Balanced Access Algorithm) is proposed according to the defects of traditional access algorithm. The loads of mesh access points are considered in the proposed algorithm, in advantage of utilizing network resource and balancing network loads. Meanwhile, DLB-HWMP is presented as the backbone WMN routing protocol to compensate HWMP, which is the standard routing protocol of IEEE 802.11s wireless mesh network, for the lack of load balancing scheme. In DLB-HWMP, hop-count load constraint weight function and middle nodes message controlling rules are applied. Mesh routers loads and the current channel quality are comprehensive considered in the improved protocol; also, messages among intermediate nodes can be shielded in the network when the network is to be found busy. Compared with HWMP, the use of network resources are optimized, congestions are well solved, and throughputs are improved. At the end of this paper, the designed load balancing scheme and the corresponding new NS2 models are described, following the analysis on simulation results for LBAA and DLB-HWMP. The experiments results show that LBAA and DLB-HWMP have excellent performance in prompt network throughputs and reduce end-to-end delay, etc.