Relay-aided Random Access for Energy-Limited Devices in the IoT

TL;DR

This paper introduces a relay-aided random access scheme for energy-limited IoT devices, enabling reliable transmission with high throughput by offloading retransmissions to relay nodes and utilizing multipacket reception.

Contribution

It proposes a novel relay-assisted random access method where relays handle retransmissions, improving efficiency and allowing simple, energy-constrained devices to achieve reliable communication.

Findings

Throughput approaches 1 with many relays

Devices can transmit reliably with low energy and complexity

Multipacket reception enables simultaneous decoding of collided packets

Abstract

In the Internet-of-Things (IoT), random access is employed for devices to share a common access channel in packet transmission with low signaling overhead. Although a retransmission strategy is necessary for packet collision resolution, it might be prohibitive for some devices due to energy and complexity constraints. In this paper, we consider a novel relay-aided random access (RARA) scheme where re-transmissions are carried out by relay nodes, not devices. Thanks to multipacket reception with multiple copies of collided signals forwarded by relay nodes, a receiver is able to recover multiple collided packets simultaneously in RARA. As a result, devices of limited complexity and energy source can enjoy reliable transmission using RARA, and the throughput can approach 1 with a large number of relay nodes.