关键词: 无线传感器网络，增强树，单跳扩展，路由跳数，能量消耗

Abstract: AEnhanced tree routing (ETR) is a routing protocol proposed recently for wireless sensor networks, in addition to parent child links,EI}R also uses enhanced links to other onchop neighbors if it is decided that this will lead to a shortcut path than Tree Routing (TR). In order to explore as much potential shortcut routes as possible, this research proposed a One-hop Expansion Enhanced Tree Routing (OEETR) protocol for wireless sensor networks. For a node that is making the routing decision,OEEI}R not only takes the enhanced links built with its onchop neighbors but also takes the enhanced links built by its one-hop father and one-hop sons with their neighbors into account,to find a shortcut route for packet forwarding. So the scope of the optional shortcut routes is no longer limited to the enhanced links built between the node and its one-hop neighbors,but expands up to the enhanced links built by its father with its one-hop neighbors and down to the enhanced links built by its sons with their neighbors,and OEETR will choose the shortest shortcut route for packet forwarding. This research presented the decision process for OEETR, and applied this protocol to ZigBee network. Simulation results reveal that OEETR not only outperforms TR and ETR in terms of hop-counts, but also saves the energy consumption than that of TR and ETR.

Key words: Wireless sensor networks, Enhanced tree routing, One-hop expansion, Hop-counts, Energy consumption