How node mobility affects k-hop cluster quality in Mobile Ad Hoc NETworks: A quantitative evaluation

Recent research activities have recognized the relevant role of k-hop clustering in Mobile Ad Hoc NETworks (MANET). k-hop clustering determination and maintenance is especially crucial to achieve scalability in large MANET scenarios, where a high number of mobile terminals dynamically build collaboration communities in ad hoc mod. Some first solutions have recently appeared in order to exploit k-hop clustering to effectively build an optimal backbone (crucial to achieve scalability) connecting all determined clusterheads in fixed ad hoc networks. However, few papers in the literature have addressed the innovative issue of evaluating how node mobility quantitatively affects the degradation of clustering quality as time passes by. To the best of our knowledge, the most relevant contribution is (Bettstetter and Krausser, 2001), where the stability of DMAC single-hop clustering is evaluated via ideal coarse-grained discrete-step simulations, by neglecting low-layer communication issues. Our paper significantly extends that contribution, (i) by focusing on k-hop clustering; (ii) by proposing a simple updating protocol to maintain clustering quality notwithstanding node mobility; (iii) by introducing a novel intuitive metric to evaluate the effects of mobility on clustering consistency; and (iv) by reporting a relevantly wider set of more realistic simulations based on ns2.