A wireless sensor network contains a large number of tiny sensor nodes that are densely deployed either inside the phenomenon to be sensed or very close to it. Sensor nodes consist of sensing, data processing, and communicating components.

The position of sensor nodes need not be engineered or predetermined. This allows random deployment in inaccessible terrain or disaster relief operations. This also means that sensor network protocols and algorithms must possess self-organizing capabilities.

Another unique feature of sensor networks is the cooperative effort of sensor nodes. Sensor nodes are fitted with an inboard processor. Instead of sending the raw data to the nodes responsible for the fusion, they use their processing abilities to locally carry out simple computations and transmit only required and partially processed data.

Since large numbers of sensor nodes are densely deployed, neighbor nodes may be very close to each other. Hence, multihop communication in wireless sensor networks is expected to consume less power than traditional single hop communication.

Furthermore, the transmission power level can be kept low, which is highly desirable in covert operations. Multihop communication can effectively overcome some of the signal propagation effects experienced in long-distance wireless communication.

One of the most important constraints on sensor nodes is the low power consumption requirement. Sensor nodes carry limited, generally irreplaceable power sources. Therefore, while traditional networks aim to achieve high quality of service (QoS) provisions, wireless sensor network protocols must focus primarily on power conservation. They must have built-in trade-off mechanisms that give the end-user the option of prolonging network lifetime at the cost of lower throughput or higher transmission delay.