A Fixed Channel Assignment Scheme for Multihop Cellular Network
Xue Jun Li, Peter Han Joo Chong · 2006
Multihop Cellular Network (MCN) has been proposed to incorporate the flexibility of ad hoc networks into traditional cellular networks. Little work has been reported on the channel assignment for MCN. In this paper, we investigate the feasibility of applying the characteristics of the hierarchical overlaid microcell/macrocell architecture and the clustering of MANETs for channel assignment in TDMA-based MCN. Based on our deliberated clustered MCN (cMCN) structure with virtual microcells, we propose a fixed channel assignment (FCA) scheme for uplink transmission. An exact Markov chain model is developed to analyze its performance. In addition, an approximated model, which can reduce the computational load greatly, with much fewer states is also found. The analytical models are validated through computer simulation. From the results, our proposed FCA scheme can reduce the call blocking probability significantly as compared with the FCA for conventional single-hop cellular system. The salient contribution is that our proposed FCA scheme can increase the spectrum efficiency and the system capacity without increasing infrastructure cost by introducing the structure of cMCN with virtual microcells. We also provide some recommendations for future work on this topic. This paper makes one major contribution to propose a channel assignment scheme for MCN. We introduce a clustered MCN (cMCN) architecture and propose a FCA scheme for use in cMCN. The proposed FCA makes use of the characteristics of both microcell/macrocell and clustering in mobile ad hoc networks (MANETs). The analytical models based on Markov chains for uplink transmission are developed. The analytical results are validated through computer simulation. The results show that the proposed FCA scheme in cMCN can increase the frequency reuse and system capacity without increasing the infrastructure cost. For example, it does not require any additional installation of new hardware's such as relay station or base station (BS). To the authors' best knowledge, this study could be the first approach to provide a solution for channel assignment scheme in MCN, as well as to provide detailed analytical and simulation results on the proposed channel assignment scheme.