In order to optimize cost and decrease complexity with a delay upper bound, the delay-constrained Steiner tree problem is addressed. Base on the new delay-constrained MPH (DCMPH_1) algorithm and through improving on t...In order to optimize cost and decrease complexity with a delay upper bound, the delay-constrained Steiner tree problem is addressed. Base on the new delay-constrained MPH (DCMPH_1) algorithm and through improving on the select path, an improved MPH-based delay-constrained Steiner tree algorithm is presented in this paper. With the new algorithm a destination node can join the existing multicast tree by selecting the path whose cost is the least;if the path’s delay destroys the delay upper bound, the least-cost path which meets the delay upper bound can be constructed through the least-cost path, and then is used to take the place of the least-cost path to join the current multicast tree. By the way, a low-cost multicast spanning tree can be constructed and the delay upper bound isn’t destroyed. Experimental results through simulations show that the new algorithm is superior to DCMPH_1 algorithm in the performance of spanning tree and the space complexity.展开更多
Many Wireless Sensor Network (WSN) systems are deployed in unattended areas using non-rechargeable batteries.To enable sustainable operations,most WSN systems employ duty-cycling mechanisms,such as Low Power Listening...Many Wireless Sensor Network (WSN) systems are deployed in unattended areas using non-rechargeable batteries.To enable sustainable operations,most WSN systems employ duty-cycling mechanisms,such as Low Power Listening (LPL).For reliable delivery of each packet with LPL,the sender has to transmit a preamble that is long enough to span over a complete sleep interval of the receiver.In this way,the sensor nodes avoid idle listening,however,at the cost of remarkably increased end-to-end delay of multi-hop packet transmissions.To address this issue,in this paper we propose a new duty-cycling mechanism called DC-Gear.DC-Gear exploits a "sleep less but save more" phenomenon,which means increasing the duty cycle in a timely and appropriate manner whileminimizing the overall energy cost and satisfying the end-to-end delay constraint.We have implemented DC-Gear with TelosB motes and demonstrated its performance advantages through extensive experiments.展开更多
文摘In order to optimize cost and decrease complexity with a delay upper bound, the delay-constrained Steiner tree problem is addressed. Base on the new delay-constrained MPH (DCMPH_1) algorithm and through improving on the select path, an improved MPH-based delay-constrained Steiner tree algorithm is presented in this paper. With the new algorithm a destination node can join the existing multicast tree by selecting the path whose cost is the least;if the path’s delay destroys the delay upper bound, the least-cost path which meets the delay upper bound can be constructed through the least-cost path, and then is used to take the place of the least-cost path to join the current multicast tree. By the way, a low-cost multicast spanning tree can be constructed and the delay upper bound isn’t destroyed. Experimental results through simulations show that the new algorithm is superior to DCMPH_1 algorithm in the performance of spanning tree and the space complexity.
基金supported by the National Basic Research Program of China(Grant No.2011CB302705)the National Natural Science Fourdation of China(60970123)
文摘Many Wireless Sensor Network (WSN) systems are deployed in unattended areas using non-rechargeable batteries.To enable sustainable operations,most WSN systems employ duty-cycling mechanisms,such as Low Power Listening (LPL).For reliable delivery of each packet with LPL,the sender has to transmit a preamble that is long enough to span over a complete sleep interval of the receiver.In this way,the sensor nodes avoid idle listening,however,at the cost of remarkably increased end-to-end delay of multi-hop packet transmissions.To address this issue,in this paper we propose a new duty-cycling mechanism called DC-Gear.DC-Gear exploits a "sleep less but save more" phenomenon,which means increasing the duty cycle in a timely and appropriate manner whileminimizing the overall energy cost and satisfying the end-to-end delay constraint.We have implemented DC-Gear with TelosB motes and demonstrated its performance advantages through extensive experiments.
