Continuous data collection applications in wireless sensor networks require sensor nodes to continuously sample the surrounding physical phenomenon and then return the data to a processing center. Battery-operated sensors have to avoid heavy use of their wireless radio by compressing the time series sensed data instead of transmitting it in raw form. One of the most commonly used compacting methods is piecewise linear approximation. Previously, Liu et al. proposed a greedy PLAMLiS algorithm to approximate the time series into a number of line segments running in Θ(n{sup}2logn) time, however this is not appropriate for processing in the sensors. Therefore, based on our study we propose an alternative algorithm which obtains the same result but needs a shorter running time. Based on theoretical analysis and comprehensive simulations, it is shown that the new proposed algorithm has a competitive computational cost of Θ(nlogn) as well as reducing the number of line segments and so it can decrease the overall radio transmission load in order to save energy of the sensor nodes.
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