應用於實際無線網路幾何繞徑的調變式合作循環橫掃方法

An effective approach to bypassing holes and recovering from greedy forwarding failure is vital for geographic routing in wireless networks. Existing localized approaches can guarantee delivery generally under the assumption of unit disk network graphs. Rotational sweep algorithms based on a circular arc, the state-of-the-art recovery method, can be employed to achieve low routing path stretch as well. However, the assumption is inappropriate for realistic wireless channels. Those approaches are thus impractical. Instead, we propose an adaptive and cooperative rotational sweep algorithm taking into account practically imperfect wireless connections. The algorithm involves a regular rotational sweep procedure and a cooperative one both making use of iterative sweepings with adaptive circular arcs. Essentially, the cooperative rotational sweep procedure resolves a potentially hidden node issue while iterative sweeping reduces the possibility of missing pivotal relays. Furthermore, to reduce futile transmissions on a routing loop, we introduce a two-dimensional routing lifetime region delimited by a total angle movement entailed by hole boundary traversal and by a maximum hop count used traditionally. Simulation results show that an extremely high end-to-end routing success probability with ingenious loop stopping can be achieved at the cost of packet header overheads for memory.