  In this paper, a cooperative localization algorithm is proposed that
considers the existence of obstacles in mobilityassisted wireless sensor
networks (WSNs). In this scheme, a mobile anchor (MA) node cooperates with
static sensor nodes and moves actively to refine location performance. The
localization accuracy of the proposed algorithm can be improved further by
changing the transmission range of mobile anchor node. The algorithm takes
advantage of cooperation betweenMAs and static sensors while, at the same time,
taking into account the relay node availability to make the best use of beacon
signals. For achieving high localization accuracy and coverage, a novel convex
position estimation algorithm is proposed, which can effectively solve the
localization problem when infeasible points occur because of the effects of
radio irregularity and obstacles. This method is the only range-free based
convex method to solve the localization problem when the feasible set of
localization inequalities is empty. Simulation results demonstrate the
effectiveness of this algorithm.
