Science and Development Network (SciDev.Net)
Hierarchical Wireless Sensor Networks (HWSNs) composing of a large number of sensors can be quickly deployed in a target environment, such as forest monitor, ocean observation, and military battlefield. There are three kinds of participants, namely: Base Station (BS), Cluster Heads (CH) and sensor nodes. In general, sensor nodes have limited computation and communication capabilities and they are randomly deployed in their corresponding cluster heads. The basic function of a cluster head is to gather sense data for authorized users and it is more resource rich than normal sensor nodes. To prevent abusively, login users and sensor nodes should be authenticated by the base station.