An Analytical Model of Channel Preemption Mechanism for WLAN-embedded Cellular Networks
The rapid growth of wireless and cellular technologies in recent years has brought in various applications in our daily life. Thus, the integration between WLAN and cellular networks has attracted more and more attention to researchers.
In this Thesis, we proposed a preemptive channel allocation mechanism for WLAN-embedded cellular networks. In such integrated networking environments, frequent handoffs may result in dramatic performance degradation. In our model, a mobile node first utilizes the cellular network for supporting high mobility. However, the capacity of a BS is easily saturated. To minimize session blocking, a mobile node outside the WLAN coverage can preempt the channel(s) occupied by a mobile node inside the WLAN coverage. The preempted mobile node can still get access to the Internet through the AP of WLAN. For the purpose of performance evaluation, we build a three-dimension Markov Chain to analyze the proposed mechanism. We derive the residence time inside the WLAN coverage and outside the WLAN coverage, respectively. Finally, we evaluate the overall network performance in terms of the number of active sessions over WLAN, the channel utilization of a BS, the probability of session blocking, the preemption probability, and the preempted probability. From the evaluation, we observe the relative performance improvements of our proposed channel preemption mechanisms.
Advisor:Wei-Kuang Lai; Tsang-Ling Sheu; Tsung-Chuan Huang; Sheau-Ru Tong; Rung-Hung Gau
School:National Sun Yat-Sen University
School Location:China - Taiwan
Source Type:Master's Thesis
Keywords:cellular markov chain preemption mobility vertical handoff wlan
Date of Publication:06/28/2007