Wireless Sensor Networks(WSNs) are composed of inexpensive, low powered microsensor nodes capable of sensing, processing and communicating with limited computational, low bandwidth and resources. WSNs are infra-structureless networks where the topology is based on the Type of Sink, number of hops, types of nodes and type of scheduling. The sensor nodes self-organize themselves dynamically to form a network and communications between nodes are established through broadcasting using radio signals. Research issues include connectivity, coverage, QoS, energy consumption, security and mobility of...