Efficient energy management policies for networks with energy harvesting sensor nodes

Abstract

Abstract-We study sensor networks with energy harvesting nodes. The generated energy at a node can be stored in a buffer. A sensor node periodically senses a random field and generates a packet. These packets are stored in a queue and transmitted using the energy available at that time at the node. For such networks we develop efficient energy management policies. First, for a single node, we obtain policies that are throughput optimal, i.e., the data queue stays stable for the largest possible data rate. Next we obtain energy management policies which minimize the mean delay in the queue. We also compare performance of several easily implementable suboptimal policies. A greedy policy is identified which, in low SNR regime, is throughput optimal and also minimizes mean delay. Next using the results for a single node, we develop efficient MAC policies.

Joint power control, scheduling and routing for multihop energy harvesting sensor networks

“…We have seen in [13], [26], [27] that for energy neutral operation in steady state, it is necessary and sufficient for the nth node to use average power < P av n . In the following, we will address the optimality problem for two scenarios: Given the traffic requirements dn of each sensor node n, obtain policies which satisfy these requirements.…”

“…The inequalities (4) state that the average power consumed for transmission, reception and sensing at each node n should be slightly less than P av n . This ensures energy neutral operation at each sensor node ( [26], [27]). We do not consider any power constraints on the fusion node whose main activity is reception (we assume that it has enough power to receive data in every slot).…”

“…It was found that having energy storage allows a larger stability region as well as a lower mean delay. Efficient Multiple Access (MAC) protocols for such sensor nodes have also been developed in [26]. In [13], we obtained optimal and easily implementable suboptimal sleep-wake policies.…”

“…In [13], [26] and [27], stochastic queuing models of data and energy generation and storage processes are considered. Stable throughput optimal and mean delay optimal energy management policies are obtained which also provide energy neutral operations.…”

Capacity and fairness of the multiple access channel in energy harvesting wireless networks

“…In this approach, only the user that enjoys the best channel gain is allowed to transmit and the assigned power is computed by temporal water-filling, similar to the single user scenario [11]. In [13], opportunistic scheduling is considered in energy harvesting networks with emphasis on queue stability rather than sum-of-rates capacity. The variation of mean delay with the packet arrival rate is characterized for certain decentralized algorithms.…”