Two ID-Free Distributed Distance-2 Edge Coloring Algorithms for WSNs

One of the most important problems for Wireless Sensor Networks (WSNs) is energy consumption since it ultimately determines the lifetime of the system. Medium Access Control (MAC) protocols based on schedules (e.g., TDMA) play an important role, since collisions and idle listening can be avoided, effectively reducing energy consumption. The problem of determining good transmission schedules for WSNs can be mapped to the distance-2 edge coloring problem in graphs, where edge colors represent slots in a TDMA-based MAC protocol, for example. In this paper, we propose and evaluate two new probabilistic and distributed distance-2 edge coloring algorithms that require no global node identifiers. We obtain analytical results for the worst-case convergence time. Moreover, we use simulations to evaluate the performance of the algorithms with respect to several metrics. Our findings indicate a tradeoff between convergence time and message overhead versus number of colors used.