论文部分内容阅读
Wireless sensor networks promise a new paradigm for gathering data via collaborationamong sensors spreading over a large geometrical region.Many applications impose delay requirementsfor data gathering and ask for time-efficient schedules for aggregating sensed data and sending tothe data sink.In this paper,the authors study the minimum data aggregation time problem undercollision-free transmission model.In each time round,data sent by a sensor reaches all sensors withinits transmission range,but a sensor can receive data only when it is the only data that reaches thesensor.The goal is to find the method that schedules data transmission and aggregation at sensorsso that the time for all requested data to be sent to the data sink is minimal.The authors propose anew approximation algorithm for this NP-hard problem with guaranteed performance ratio (7Δ)/(Iog_2|S|)+c,which significantly reduces the current best ratio of Δ-1,where S is the set of sensors containingsource data,Δ is the maximal number of sensors within the transmission range of any sensor,and c is aconstant.The authors also conduct extensive simulation,the obtained results justify the improvementof proposed algorithm over the existing one.
Wireless sensor networks promise a new paradigm for gathering data via collaborationamong sensors spreading over a large geometrical region. Many applications impose delay requirements for data gathering and ask for time-efficient schedules for aggregating sensed data and sending tothe data sink. In this paper, the authors study the minimum data aggregation time problem undercollision-free transmission model. each time round, data sent by a sensor reaches all sensors withinits transmission range, but a sensor can receive data only when it is the only data that reaches thesensor. goal to find the method that schedules data transmission and aggregation at sensorsso that the time for all requested data to be sent to the data sink is minimal. These authors propose a new approximation algorithm for this NP-hard problem with guaranteed performance ratio (7Δ) / ( Iog_2 | S |) + c, which significantly reduces the current best ratio of Δ-1, where S is the set of sensors containing source data, Δ is the ma ximal number of sensors within the transmission range of any sensor, and c is aconstant. The authors also conduct extensive simulation, the result results justify the improvement of proposed algorithm over the existing one.