Abstract
Wireless sensor networks can be thought as wireless ad hoc networks with limited energy supply and restricted computation ability. However, unlike traditional local area networks or wireless networks, sensor networks should take these constraints into consideration. Energy limitation and routing fidelity are two of the most concerns in developing protocols and algorithms for wireless sensor networks. To achieve these two goals, many researches focus on how sensor nodes coordinate with each other to turn off their radio intermittently, thus reduce their energy consumption. For example, Geographical Adaptive Fidelity (GAF) [1] conserves energy by using geographic location information to identify the equivalence between nodes then turn off redundant nodes. In this thesis, a grouping GAF method is proposed. It replaces GAF virtual grid with hexagonal cell first, and periodically rotates the active nodes between several groups (partition of nodes). Theoretically the proposed method wakes up only 51.96% of nodes that GAF does without losing the property of network connectivity. The simulation results show that with our algorithm, we awake only 50.69% of the nodes compared to GAF with additional 1.16% packet delivery delay.