QoS and Burst Transmission Enabled MAC Protocol for Ambient IoT

Abstract

Energy harvesting technology enables Internet of Things (IoT) devices to harvest energy from ambient sources like the sun, radio signals, and others. However, due to the uncertainty in available energy caused by surrounding conditions, these devices may face energy scarcity issues. This can be addressed by devising energy harvesting-aware schemes, such as Medium Access Control (MAC) protocols and task scheduling algorithms, to meet the desired application performance. For instance, a monitoring application generates periodic (low priority) and event-based (high priority) data traffic with different transmission requirements. Thus, such application requires minimum delay for high-priority packets under dynamic harvesting conditions. Nevertheless, the existing protocols for ambient-powered IoT have limited consideration in supporting low-priority packets, which often remain in the queue. As a result, these packets suffer longer delays and may even be dropped. This work proposes a Quality of Service (QoS) and burst transmission enabled protocol called QBT-MAC. QBT-MAC utilizes separate queues for both high and low priority data packets and introduces a burst transmission technique to minimize the delay and maximize the packet delivery ratio for low-priority packets. Simulation results show that QBT-MAC achieves better performance in terms of average delay, packet delivery ratio, and energy efficiency with improvements of up to 69.3%, 15.8%, and 13.6%, respectively when compared with QPPD-MAC and EEM-MAC protocols.