Modeling and Analysis of Handoffs in Cellular and WLAN Integration

In this paper, we propose an integrated service-based handoff scheme with (ISBQ) and without queue capability (ISB) for the cellular and WLAN integration. The proposed handoff schemes take into account the different services supporting ability, user mobility and vertical handoffs in the integrated network. The system is modeled using multidimensional Markov chain and a numerical analysis is presented to evaluate the most important performance metrics such as the blocking probability of originating calls, dropping probability and average transfer time. The effects of data user mobility are also studied in the paper. It is shown through comparisons with the conventional WLAN first (WF) handoff scheme that the ISB and ISBQ scheme can provide better quality of service (QoS) for mobile subscribers. Especially, the ISBQ outperforms other schemes in reducing the blocking probabilities of originating data calls and dropping probabilities of data calls, as well as guaranteeing the performance of voice calls.