Research On Multicast Problem In Duty-Cycled Wireless Sensor Networks

Sensor nodes in wireless sensor networks usually use batteries to provide energy.It is difficult to replace batteries for all nodes deployed in the monitoring area.It is very important to reduce the energy consumption of data communication.Thus,reducing the energy consumption of data communication in wireless sensor networks is an important research issue.The duty-cycled model is usually used to reduce the energy consumption of multicasting in data communication.However,with duty-cycled model,due to the sleep delay,the delay of data transmission between nodes will be greatly increased.In wireless sensor networks,it is necessary to publish the important information of the sink node to the sensor nodes as soon as possible,so that the relevant sensor nodes can adjust.Therefore,it is very meaningful to reduce the transmission delay of multicasting in dutycycled wireless sensor networks.The problem of minimum energy multicasting in duty-cycled wireless sensor networks is to select suitable forwarding nodes and transmission schedule to reduce the energy consumption of multicasting.For the minimum transmission delay multicasting problem in duty-cycled WSNs,a multicast tree is usually constructed and the nodes in the tree are scheduled to reduce the multicasting transmission delay without interference.This paper focuses on the minimum energy multicasting problem and the minimum transmission delay multicasting problem in duty-cycled wireless sensor networks.For the minimum energy multicasting problem,this paper proposes an ATPM(Adjustable Transmission Power Multicasting)algorithm,which combines duty-cycled model and adjustable transmission power of node.In the algorithm,an auxiliary graph is constructed to select the appropriate forwarding nodes and transmission schedule,because the auxiliary graph shows the corresponding relationship between the possible working time slots and transmission power of nodes in original graph and the neighboring nodes that can transmit data.Based on the previous solution to the minimum energy multicasting problem,a WPI(Without Protocol Interference)algorithm is proposed to reschedule the relevant nodes to resolve protocol interference.Simulation results show that ATPM algorithm outperforms other algorithms in energy consumption under different network parameters.ATPM compares other algorithms in terms of transmission delay,protocol interference ratio.The performance of minimum energy multicasting algorithms without protocol interference are verified.For the problem of minimum transmission delay multicasting,this paper studies the transmission delay of broadcasting.A minimum transmission delay broadcasting tree constructed and scheduled algorithm MLB(Minimum Latency Broadcasting)is proposed.This algorithm starts from the source node and expands the broadcasting tree layer by layer by adding nodes.When adding nodes,the broadcast tree takes reducing the transmission delay from source node to each node as the standard,and ensures that there is no protocol interference between the node and any node in the broadcast tree.When the newly added nodes interference with the nodes already in the broadcast tree,PIABS(Protocol Interference Avoid Broadcasting Scheduling)algorithm shows that the transmission schedule of the node with small add in transmission delay is first modified to reduce the transmission delay of the broadcast tree.Simulation results show that the MLB algorithm outperforms other algorithms in terms of transmission delay under different network parameters.