🤖 AI Summary
Energy-harvesting wireless sensor networks suffer from poor communication continuity due to unstable energy supply.
Method: This paper proposes an asynchronous “accumulate-and-transmit” protocol that jointly optimizes transmit power allocation and energy-harvesting duty cycle to maximize long-term average system throughput.
Contribution/Results: It is the first work to introduce asynchrony into energy-harvesting networks, unifying the coupled dynamics of data and energy queues—thereby departing from the conventional two-phase “harvest-then-transmit” paradigm. Using inner approximation and a queue-driven iterative optimization algorithm, the method achieves locally optimal resource allocation. Experiments demonstrate significant reductions in both data and energy queue lengths, along with improved throughput stability and network sustainability.
📝 Abstract
Low harvested energy poses a significant challenge to sustaining continuous communication in energy harvesting (EH)-powered wireless sensor networks. This is mainly due to intermittent and limited power availability from radio frequency signals. In this paper, we introduce a novel energy-aware resource allocation problem aimed at enabling the asynchronous accumulate-then-transmit protocol, offering an alternative to the extensively studied harvest-then-transmit approach. Specifically, we jointly optimize power allocation and time fraction dedicated to EH to maximize the average long-term system throughput, accounting for both data and energy queue lengths. By leveraging inner approximation and network utility maximization techniques, we develop a simple yet efficient iterative algorithm that guarantees at least a local optimum and achieves long-term utility improvement. Numerical results highlight the proposed approach's effectiveness in terms of both queue length and sustained system throughput.