Reducing handover latency using cross layer protocol in MIPV6-based wireless local area networks

Abstract

The rapid development of wireless technologies has resulted in a movement towards total mobility. Mobility is an essential and necessary feature for roaming users who connect to different wireless networks via APs. Mobility provides users with the freedom of movement and real-time communication such as VoIP and video between mobile and stationary users. The application of such communication requires an efficient protocol to provide seamless connections. Existing protocols such as MIP, MIPv6, FMIPv6 and HMIPv6 provide mobility to users. These protocols suffer from handover latency, delivery ratio, packet loss and signal overhead due to data link and network layer process execution. Besides these problems, wireless networks also suffer from unnecessary handovers due to the mobility pattern, cell structure and variable mobile node speed. However, handover latency has become an important issue in the research world that needs to be resolved through the design of an efficient cross layer protocol and topology by considering wireless network characteristics. This research first proposed an enhancement to the Layer 2 reassociation signal based on passive scanning called Enhanced Reassociation (EN-ReAS). The enhancement will allow a mobile node to transmit a previous IP address during the reassociation process. Secondly, an Efficient Mobile IPv6 (EF-MIPv6) is proposed in order to reduce the average delay, packet loss and total handover latency by enhancing the router advertisement and router solicitation signals. Finally, an Efficient Wireless Topology Design (EF-WTD) is proposed based on cell structure and minimum overlapping area to enable the mobile node to make a proper handover decision. The designed EnReAS, EF-MIPv6 and EF-WTD solutions were implemented and then compared with standard and cross-layer mobility solutions. Multiple practical test-bed and simulation experiments were carried out with different scenarios at Layer 2, Layer 3 and in the topology design. The simulation results showed that EN-ReAS performed better than the standard Layer 2. Secondly EF-MIPv6 improved handover latency and packet drop rate in comparison to MIPv6, FMIPv6, SFMIPv6 and EnFMIPv6. Thirdly, the EF-WTD model provides better handover rate, less packet loss, while keeping the same handover latency. The proposed design has proven that the handover latency could be reduced significantly and this would lead to the enhancement of mobility in wireless networks.