Details of Research Outputs

In wireless sensor networks (WSNs), energy efficiency and low delay are two pivotal issues for data collection. Wireless sensor networks are composed of energy-constrained sensor nodes. While sensing the environment, the rapid transmission of data to the sink is critical for many applications. In order to save energy, the duty cycle based mode is adopted in most studies, but this method increases the data transmission delay. Thus, an Adding Duty Cycle Only in Connected Dominating Sets (ADCOCDS) approach is proposed in this paper, which can effectively reduce network energy consumption and delay. The main innovations of the ADCOCDS scheme are as follows: (1) Unlike the mode of the duty cycle for all nodes in the previous WSNs, in ADCOCDS scheme, we choose a part of nodes to construct as a connected dominating set, and these nodes adopt the mode of duty cycle. For other nodes in the network, the radio transmitter is turned off to save energy when there is no data to transmit, and when these nodes have data to send, they turn on the radio transmitter and send the data to nodes in the dominating set, then nodes in the dominating set transfer the data to sink. In ADCOCDS scheme, since only a small number of nodes adopt the duty cycle mode, the energy efficiency of the network is high; (2) In WSNs, we observed that the energy consumption of nodes in the near-sink area is higher than that in the far-sink area. Therefore, in the ADCOCDS scheme, we increase the duty cycle of nodes according to their energy consumption to reduce the delay. Through theoretical analysis and experimental results, the ADCOCDS scheme can effectively reduce energy consumption and delay by 12.09%-43.17% and 21.85%-57.96%, respectively, while improving network lifetime by 10.71%-24.13% compared with previous strategies.