Load-balancing and Inter-domain Mobility for Wireless Mesh Networks

Abstract —This paper proposes a scheme for domain partition to achieve the tradeoff between load-balancing and inter-domain mobility to reduce the negative impact of the host mobility. The load-balancing scheme for domains includes: an initialization procedure to divide a mesh network into domains, and a load adjustment procedure to rebalance the traffic load of neighboring domains when required. Moreover, the proposed scheme provides inter-domain mobility in support of multi-hop communication with the Multi-hop cellular IP (MCIP) mobility protocol. Our experimental results show that the proposed protocol effectively controls the migration of mesh routers as well as mobile stations. Keywords-Domain, Mobility, Load-balancing, Mesh Network I. I NTRODUCTION Wireless Mesh Router Wireless mesh networks have been increasingly gaining attention in the last few years. Mesh networks not only provide high bandwidth Internet access, but also offer low-cost and flexible deployment from commercial market perspective. One of the typical applications is mesh community networks to provide Internet connections with shared broadband, in place of cables and DSLs with which the network service is expensive for users. Rather than a community, with complicated routing technologies, wireless mesh networks (i.e., enterprise networks) can be built in larger areas such as airports, hotels, shopping malls, or office buildings, etc. Different from pure ad hoc networks, mesh networks are tightly integrated with the Internet through Internet Gateways (IGWs) that act as Internet attachments for mesh routers as well as their associated mobile stations (MSs). The wireless link capacity of IGWs will be the bottleneck for a mesh network. Therefore, in order to reduce the domain congestion, a load-balancing approach is needed to direct the router traffic toward a light-loaded IGW. When a router changes its IGW, it incurs the inter-domain mobility of its associated MSs [1]. The process of inter-domain mobility may seriously degrade network performance in the case of the inter-domain migration of mesh router frequently happens between two neighboring domains. The focus of this paper is to build a load-balancing approach that provides the tradeoff between load-distribution among IGWs and Internet mobility of MSs. The proposed approach for load-balancing not only balances the traffic load among domains, but also accordingly executes appropriate mobility operations to support the desirable inter-domain mobility. It effectively reduces the negative impacts caused by inter-domain mobility. The rest of this paper is organized as follows: the background is discussed in Section II. Then, Section III describes our domain partition and adjustment algorithms. The enhancement of Multi-hop cellular IP further implements the inter-domain mobility of MSs in Section IV. In Section V, experiments illustrate the tradeoff between domain partition and inter-domain handoff. Section VI concludes the paper. II. B