Geocasting in wireless sensor and ad hoc networks means delivering a message from a source node to all the nodes in a given geographical region. The objectives of a geocasting protocol are two-fold: guaranteed message delivery and low transmission cost. Most of the existing protocols do not guarantee message de-livery, and those that do, incur high transmission costs.   In this study, we propose the concept of Virtual Surrounding Face (VSF), and design a VSF-based geocasting protocol (VSFG). We also design a SKIP method and a local dominating set (DS) based restricted flooding technique to further reduce the cost of VSFG. Through mathematical analysis and comprehensive sim-ulations, we show that VSFG, together with SKIP and local DS based restricted flooding, guarantees message delivery and has a much lower transmission cost than the previous approaches. The reduction of cost can be up to 65% compared with the most effi-cient existing approach.
['Jie Lian', 'Yunhao Liu', 'Kshirasagar Naik', 'Lei Chen']
Virtual surrounding face geocasting in wireless ad hoc and sensor networks