基于接收信号强度指示,提出一种无线传感器网络节点定位的伪节点规划算法FNP(Fake node and programming).算法假设网络中有部分已知位置的锚节点,并将RSSI值转化为未知节点与锚节点间的距离.在区域内插入若干伪节点,利用0-1规划选出满足可通信节点间的距离约束的伪节点,得出未知节点的位置.该算法设计简单,节点间只需广播一次,通信开销少.仿真结果表明,该算法具有较小的节点定位误差.
Opportunistic routing(OR) could adapt to dynamic wireless sensor networks(WSNs) because of its inherent broadcast nature.Most of the existing OR protocols focus on the variations of propagation environment which are caused by channel fading.However, a few works deal with the dynamic scenario with mobile nodes.In this paper, a mobile node(MN) aware OR(MN-OR) is proposed and applied to a WSN in the high-speed railway scenario where the destination node is deployed inside a high speed moving train, and the MN-OR not only considers the mobility of node but also utilizes the candidate waiting time induced by the timer-based coordination scheme.Specifically, to reduce the number of duplicate transmissions and mitigate the delay of information transmission, a new selection strategy of the candidate forwarders is presented.In addition, two priority assignment methods of the candidate forwarders are proposed for the general relay nodes(GRNs) and the rail-side nodes(RSNs) according to their different routing requirements.Extensive simulation results demonstrate that the proposed MN-OR protocol can achieve better network performances compared with some existing routing schemes such as the well-known Ad-hoc on-demand distance vector routing(AODV) and the extremely opportunistic routing(ExOR) protocols.
