Relay-aided Slotted Aloha for Optical Wireless Communications

TL;DR

This paper proposes a relay-aided Slotted ALOHA protocol for optical wireless IoT networks, analyzing its throughput performance over combined indoor optical wireless and outdoor RF channels, highlighting the benefits of relay deployment.

Contribution

It introduces a novel relay-assisted uplink access scheme for OWC-based IoT, combining indoor optical wireless and outdoor RF links, and evaluates its performance under various conditions.

Findings

Relay deployment improves throughput under certain conditions.

Performance depends on channel quality and traffic load.

Relay-aided scheme outperforms non-relay schemes in specific scenarios.

Abstract

We consider a relay-aided Slotted ALOHA solution for uplink random access for an Optical Wireless Communications (OWC)-based Internet of Things (IoT). The first phase of uplink, the one between IoT devices and the relays, is realized using indoor OWC, while the second phase, between the relays and a base station, represents the long-range RF transmission based on low-power wide area network such as LoRaWAN and occurs outdoors. The throughput performance dependence on the OWC and RF channel conditions is observed. The behavior of the performance gain due to adding relays is highlighted and investigated under different channel and traffic conditions.