Handoff Architecture for Heterogeneous Wireless Environment

Future wireless networks must be able to coordinate services within a diverse network environment. Next generation wireless network is envisioned as a convergence of different wireless access technologies providing the user enhanced connection any where any time to improve the systems resource utilization. In such converged systems, co-existence of heterogeneous access technologies with largely different characteristics like data rate for cellular network (2 Mbps), WLAN 802.11b (11 Mbps) and HIPERLAN (54 Mbps) results in handoff asymmetry that differs from the traditional intra-network handoff (horizontal handoff). The seamless and efficient handoff between different access technologies (vertical handoff) is essential and remains a challenging problem. In this paper, we are trying to focus mainly on the handoff for the heterogeneous environment. Key WordsHeterogeneous Networks, WLAN, Vertical Handoff (VHO), Horizontal Handoff (HHO), Quality of Service (QoS).