Latency Minimization Based Handover by using Floating Threshold Request

Abstract

Many research works carried out towards achieving faster and more reliable handover techniques in a Mobile WiMAX (Worldwide Interoperability for Microwave Access) network. Handover, also called handoff, is the critical mechanism that allows an ongoing session in a cellular mobile network like WiMAX to be seamlessly maintained without any call drop as the Mobile Station (MS) moves out of the coverage area of one base station (BS) to that of another. Mobile WiMAX supports three different types of handover mechanisms, namely, the hard handover, the Fast Base Station Switching (FBSS) and the Micro-Diversity Handover (MDHO). Out of these, the hard handover is the default handover mechanism whereas the other two are the optional schemes. Also, FBSS and MDHO provide better performance in comparison to hard handover, when it comes to dealing with the high-speed multimedia applications. However, they require a complex architecture and are very expensive to implement. So, hard handover is the commonly used technique accepted by the mobile broadband wireless user community including Mobile WiMAX users. Also call handover technique comes with some problem such as delay in response, loss of information, disturbance, insecure communication, and out of coverage area etc. creates inefficient communication and decreases QoS. The cause of problem can be due to overloaded BS, latency delay and inefficient handover decision. This produces poor end-to-end performance which future produces low throughput, less total packet received, high end-to-end delay etc. This level of QoS is not sufficient for good call handover in mobile WiMAX. In the Proposed scheme, the standby request based call or data handover mechanism has been proposed for the purpose of soft handover and to reduce the call drop rate during the process of changing the cell due to the movement of the user. The standby request mechanism has been designed to establish the semi-active connection with the non-active BTS within range. The semi-active connection is transferred to the active state once the connection is established between the cellular node and the in Range non-active base station. The intimation is given to the previous BTS to shift all active connections o the non-active base station, which minimizes the call drop rate. The experimental results have also revealed the efficiency of the proposed model in comparison with the existing model.