A Novel Multi-hop B3G Architecture for Adaptive Gateway Management in Heterogeneous Wireless Networks

In this paper, a multi-hop B3G architecture, which is a heterogeneous wireless network (HWN) architecture, integrating MANET, infrastructure WLAN with 3G UMTS network, is considered for the purpose of providing anytime, anywhere data access as it utilizes the higher bandwidth rates of MANET and WLAN networks and wider range of communication of 3G network. The issues of gateways in HWN, which serve as a liaison between the MANET/WLAN and UMTS, are analyzed in this paper. A multi-metric gateway selection mechanism using simple additive weighting (SAW) of MANET node metrics such as residual energy, 3G signal strength and mobility speed, is used to select an optimal gateway from the dual-interface-enabled gateway candidates. As transaction progresses, when the above-mentioned metrics of the gateway reach their respective pre-defined threshold values, thereby, affecting optimality of the current gateway, a multi-metric adaptive gateway migration mechanism (MAGMM) is proposed, which migrates the responsibility of the current gateway to a newly-selected optimal gateway, in order to sustain connectivity of the integrated network. This MAGMM is incorporated in the considered multi-hop B3G architecture and hence it is termed as adaptive gateway management-based multi-hop B3G network (AGMMB3G) architecture. In addition to MAGMM, this paper also compares AGMMB3G with the other existing HWN architectures. Simulations are carried out in HWN environment using NS2 and the results show how MAGMM enhances the overall HWN performance in terms of transaction duration, packet delivery ratio and control packet overhead parameters.