The Impact of the Physical Layer on the Performance of Concurrent Transmissions

TL;DR

This study investigates how different physical layer properties influence the performance of concurrent transmissions in low-power wireless protocols, combining simulations and real hardware experiments to provide comprehensive insights.

Contribution

It is the first extensive analysis of the impact of physical layer characteristics on CT-based solutions using IEEE 802.15.4 and BLE 5, including experimental validation.

Findings

Performance highly depends on physical layer choice

Errors from de-synchronization and beating vary with physical layer

Physical layer affects protocol dependability under interference

Abstract

The popularity of concurrent transmissions (CT) has soared after recent studies have shown their feasibility on the four physical layers specified by BLE 5, hence providing an alternative to the use of IEEE 802.15.4 for the design of reliable and efficient low-power wireless protocols. However, to date, the extent to which physical layer properties affect the performance of CT has not yet been investigated in detail. This paper fills this gap and provides the first extensive study on the impact of the physical layer on CT-based solutions using IEEE 802.15.4 and BLE 5. We first highlight through simulation how the impact of errors induced by de-synchronization and beating on the performance of CT highly depends on the choice of the underlying physical layer. We then confirm these observations experimentally on real hardware through an analysis of the bit error distribution across received packets, unveiling possible techniques to effectively handle these errors. We further study the performance of CT-based flooding protocols in the presence of radio interference on a large-scale, and derive important insights on how the used physical layer affects their dependability.