Distributed initialization algorithms for single-hop ad hoc networks with minislotted carrier sensing

An ad hoc network is a self-organized and distributed entity, consisting of n mobile stations (MSs) without the coordination of any centralized access point. Initialization is one of the fundamental tasks to set up an ad hoc network, which involves assigning each of the n MSs a distinct ID number from 1 to n, distributedly. In Nakano et al. (2000), randomized initialization protocols are developed for single-hop ad hoc networks under different conditions. However, carrier sensing has not been utilized and suitable acknowledgment schemes for the algorithms are not developed. Moreover, the assumption taken by Nakano et al. about MSs being able to listen while transmitting is not valid for ad hoc networks. In this context, we describe two algorithms for initializing an ad hoc network with carrier sensing capability. First, a novel acknowledgment scheme is proposed for notifying a transmitting MS whether its transmission is successful during the initialization. Then, two distributed and randomized initialization algorithms are developed and analyzed, under the assumptions of a known and unknown number of users in the network, respectively. Both algorithms are obtained based on optimizing some key parameters to minimize the total time required to complete the initialization. Both theoretical analysis and simulations indicate that the proposed initialization algorithms outperform the existing methods, in the sense that they take much less time to complete the initialization and the average number of transmission attempts before success is much smaller.