Date Added: Oct 2012
Wireless sensor networks, have authorized data gathering from a vast geographical region, and for a wide range of tracking and monitoring application from both civilians and military domains, unprecedented opportunities is present. To the demands of the network users, it is expected that the WSNs would process, store and provide the sensed data to the users. As the most common communication pattern, it is expected that the network users issue the queries to the network before obtaining the information of their Internet. Moreover, in Wireless Sensor and actuator Networks (WSNs), commands to the network may be issued by the network users (probably based on the data he/she received from network).