Analysis on DV-Hop Algorithm and its variants by considering threshold

Wireless Sensor networks is a network of lowpriced, small sized and energy constraint sensor nodes where each sensor node is programmed to sense the events and send it to the Base station using multi-hop communication. In almost all applications of Wireless Sensor Networks, event detection information is required along with the location of the event. Thus, to find the location of event, node localization plays an important role. Many researchers have put tremendous efforts in designing localization algorithms. In the literature, it is confirmed that DV-Hop algorithm and its variants are the most suitable range-free based algorithms for node localization, due to its cost effectiveness, simplicity and feasibility for medium to large scale networks, but these algorithms consume very high energy. The DV-Hop algorithm works in three phases. The first phase allows all the nodes to get their distance from few localized nodes called anchors in terms of hop. The hop is the count of neighboring nodes between two nodes. Then in second phase, the anchor nodes find out their approximate distances from every node. The third phase computes the location of node using the information obtained from first two phases and by applying trilateration method. The high energy is consumed due to transmission of large number of packets in the first two phases by anchor nodes. In order to reduce communication overhead of the first two phase of DV-Hop, an improved DV-Hop is proposed that considers only k-hop transmission of the anchor packet which reduces the communication overheads to the large extent. Simulation experiments and results prove that the proposed method reduces the energy consumption by approximately 50% compare to the traditional DV-Hop algorithm.