Research On Bulk-data Dissemination Protocols In Duty-cycled Wireless Sensor Networks

Wireless sensor networks are multiple hops, self-organizing networks, which consists of a large number of sensors deployed in the designated area though wireless communication.The sensors are battery-powered,which makes it very hard to replace the battery after power being exhausted. The nodes always work with duty-cycle mode which always makes nodes switch between the dormant state and working state for energy-saving.During the networks' running processes, users may modify the error codes run in the sensor nodes or part of function software of the node, which may lead to update the whole system of sensor nodes.it is impossible to update the software of every node for the large-scale sensor networks.Under this circumstances, bulk-data dissemination can be a more effective way to update the whole sensor networks.Bulk-data dissemination is a crucial subject of wireless sensor network field,which attracts widely attention.But now data dissemination protocols available do not work with duty cycle mode,that is the nodes are always in the working state,which goes against duty cycle mode that nodes should work with.This paper introduces a study of data dissemination protocol of duty cycle network.Main contents:1) Propose channel reservation and hardware response technology for higher effeciency and reliability2) Propose a dissemination protocol based-on the waking time of neighbor nodes to reduce the waiting-time of the data dissemination in which nodes work in a asynchronous-sleep scheduling scheme.In this case,nodes send data with higher priority to the neighbor who wakes up earlier, and utilize the channel reservation and hardware response technology at the same time to enhance the effeciency of transmission. Moreover, node can obtain the dissemination data by overhearing the data to decrease the redundancy.3) The dissemination protocol based on waking time of neighbor nodes reduces the latent delay, but such a protocol does not consider how to disseminate data quickly. To reduce the completion time of dissemination, we further propose a dissemination protocol based on the priority of nodes, where the priority of the node can be determined according to the depth and height of the node, which are the distance to the sink node and the distance to its farthest leaf node respectively.4) Finally, we make a simulation and analysis to compare our protocol with Deluge. The simulation results show that with the increasing of data, the cost time of the dissemination protocol proposed is similar to the cost time of Deluge protocol,in addition its the energy cost is less than Deluge's energy cost dramaticaly.