Research Of Energy-efficient Transmission Scheduling Protocols Based On Vertex Coloring For Wireless Sensor Networks

Energy control is one of the key issues need to be solved in the applications of wireless sensor networks. This paper aims at controlling of data transmission energy which is remarkable in energy consumption of wireless sensor networks. An improved sleep/wakeup protocol and a vertex coloring based link scheduling protocol are proposed in this paper. The sleep/wakeup protocols reduce transmission energy cost by decrease idle listening frequency. STEM (Sparse Topology and Energy Management) protocol is a typical distributed, on-demand sleep/wakeup protocol which uses two radios in its applications. The paper improves the STEM protocol using time division method and proposed STEM-TDV (STEM-Time Division Variation) protocol, which makes the original STEM protocol suitable for single radio networks. To avoid transmission conflict in wireless sensor networks, the paper further proposes a high energy-efficient link scheduling protocol VCLS (Vertex Coloring based Link Scheduling). The VCLS protocol adopts vertex coloring method in link scheduling of wireless networks, and can obtain conflict-free timeslot allocation for wireless links. A distributed implementation of the VCLS protocol is show in this paper, which can avoid delay and packet loss problems caused by long-distance multihop forwarding in centralized implementation. Simulation results show that the improved sleep/wakeup protocol STEM-TDV has a low energy cost than the original double-radio scheme, and the proposed VCLS protocol has better performance than conventional scheduling protocols such as IHLS and DRAND in energy consumption, space reuse rate and packet loss rate.