Optimal Energy Supplementary and Data Transmission Schedule for Energy Harvesting Transmitter With Reliable Energy Backup

Abstract

For the Energy harvesting (EH) transmitter equipped with a Reliable Energy Backup (REB), the following problem is challenging and important: how to minimize the amount of energy supplied by the REB, such that the harvested energy is efficiently utilized for transmitting a given amount of data within a fixed delay constraint. In this paper, we first develop a stochastic model for this problem. We then discuss the optimization issue of delay-constrained data transmission over a fading wireless channel. We transform the delay constraint into the penalty function, and then the energy constrained control problem is modeled as a Markov decision process (MDP) without constraint, by which we obtain the optimal energy supplementary policy and the minimum of the expected energy consumption from REB. In the special case that the energy of the transmitter is supplied by REB alone, we find that the optimal energy supplementary policy is non-decreasing in the elapsed transmission time and for the remaining task of data transmission. This substantially reduces the computational complexity required to implement the optimal energy supplementary policy for a general EH wireless device. Numerical studies validate the theoretical findings, and observations are outlined to demonstrate the characteristics of the optimal energy supplementary policy and the minimum expected energy expenditure from the REB.

Optimal Update for Energy Harvesting Sensor with Reliable Backup Energy

“…Based on this unique threshold structure, we propose a modified value iteration algorithm to solve the optimal policy, as shown in Algorithm 1. Specifically, We first iterate the Bellman equation (11) to obtain the value function. Then based on the threshold structure, the optimal policy can be obtained without calculating the equation (13) in each state, which reduces the computational complexity.…”

“…[8]- [10] investigate AoI-minimal status updating policies for sensor networks that rely solely on harvested energy. In [11]- [13], although the sensors can use both harvested energy and reliable energy, the authors only optimize for delay or throughput and ignore the timeliness of the system. Based on our settings, we will minimize the long-term average weighted sum of the AoI and the paid reliable energy cost to find the optimal information updating policy.…”

Optimal Information Update for Energy Harvesting Sensor with Reliable Backup Energy

“…Hence, in this case, the reliable energy can serve as backup energy. The design of the coexistence of reliable backup energy and harvested energy has been researched and promoted in academia and industry [ 8 , 11 , 12 , 13 , 14 ]. The mixed energy supply mode can enhance the reliability of the system.…”

Optimal Update in Energy Harvesting Aided Terahertz Communications with Random Blocking

“…Nevertheless, at the same time, this also brings about the problem of energy management. Since harvested energy is free to use while the use of reliable energy requires a price, the wireless sensor should make full use of the harvested energy and minimize the backup energy consumption [11]- [13]. However, in the information update system, keeping the data fresh while minimizing the cost of using reliable energy is still an open problem.…”