|Ali Sehati||University of Calgary, Canada|
|Majid Ghaderi||University of Calgary, Canada|
This paper considers energy management on LTE-enabled Internet of Things (IoT) devices. A characteristic feature of IoT applications is the periodic generation of small messages, whose transmission over LTE is highly energy inefficient. In this paper, we consider application message bundling to alleviate the effect of short message transmissions on energy consumption. Specifically, we model the interplay between energy consumption and the extended DRX mechanism introduced in LTE to deal with IoT traffic. We formulate bundling as a cost minimization problem and develop an online algorithm to solve the problem. Detailed analysis shows that, depending on DRX and application parameters, our algorithm is 1, 2, or 4-competitive with respect to the optimal offline algorithm that knows the entire sequence of application messages a priori. We evaluate the performance of the proposed algorithm and the accuracy of our analysis in a range of realistic scenarios using both model-driven simulations and real experiments on an IoT testbed. Our results show that, i) depending on application requirements, energy savings ranging from zero to about 100% can be achieved using our algorithm, and ii) ignoring DRX could significantly overestimate or underestimate energy consumption.