The advancement in wireless networking and wireless device technology are paving the way for bringing the vision of ubiquitous communication to reality. This vision will be enabled by the interworking of existing wireless multihop wireless networks. However, the diversity in the design and operation of these wireless networks may not enable users to enjoy continuous network service as they traverse between networks. This paper presents a framework which ensures continuous service and sustains

more »

... acceptable service level quality for network users transiting between multiple multihop wireless networks. The focus is on the scenario where a user utilizes multiple hops to access any of the multiple networks. We classify the components of the framework into link discovery, resource optimization and routing Network Protocols and Algorithms ISSN 1943-3581 2012 www.macrothink.org/npa 6 processes. A set of analytical models and metrics are defined for these processes and the framework evaluated with simulations. The findings show that despite an increase in simultaneous network users, which degrades network performance, the framework is able to support quality continuous service for users transiting between networks. 7 provides a review of interworking wireless networks. Section 3 explains the challenges of traffic engineering in interworking multihop wireless networks. Section 4 illustrates the deployment scenario considered in this research. Sections 5 and 6 present the analysis of the link availability and non-impairment probability models. The connectivity model is presented in section 7 while section 8 analyzes the simulation performance of the framework. Review of interworking wireless networks A lot of research work has gone into the interworking of single-hop WWAN (e.g. 3G) and single-hop WLAN (e.g. IEEE802.11). Standardization groups such as the Third Generation Partnership Project (3GPP) [5] and 3GPP2 [6] have dealt with the interworking of 3G and WLANs. The interworking of heterogeneous IEEE 802 networks and between IEEE 802 networks and cellular networks has also been dealt with by standardization groups. However, they have only considered the single-hop mode of operation, where only two connection options are available. These options are: 1) direct connection between a mobile terminal and a cellular Base Station (BS) or 2) direct connection between a mobile terminal and an Access Point (AP). The paradigm of multihop communication was not exploited. Even though coverage extension and relaying via multihop communication is an old concept, it has become practical only recently [7] . Practitioners expect that in the future, wireless networks will not be limited to cellular systems [8] . It is envisaged that parts of the access domain in next generation wireless networks will not be centrally organized, instead they will be infrastructure-less and provide multihop communication for nodes that cannot reach their destination with a single hop transmission [9] . Mobile terminals (nodes) may access network services by forming alliance with other nodes any time and any place. Such nodes could be a part of the personal, local and wide area sphere of wireless networking. The nodes would temporarily co-operate to provide ubiquitous access and service continuity for each other [9] . In addition, to reduce the problem of dead spot in cellular networks, multihop cellular networks are also being considered [10]. .macrothink.org/npa 15 positioned nodes in the network is represented by (2). The probability that a communication link is available for any node is related to the link distance distribution [22] . A link is a 1-hop communication connection between node pairs and a route is a last mile multihop communication connection. Also, the probability that a last mile multihop communication path is available is related to the availability of the individual links that make up the path. As long as β T,R ≤R o , a link is available (exists) between any two arbitrary nodes. Therefore, the CDF of the link distance β T,R can be taken as the probability that at least a link is available for transmission. Thus, the availability of a link in a network is a function of R o , β T,R and µ Net . If P link represents the availability of a 1-hop link, then, P link is: (3) 0 Copyright Disclaimer