Sidelink Technologies Comparison for Highway High-Density Platoon Emergency Braking

We present a benchmarking framework for different radio access technologies (RATs) in a high density platooning (HDPL) emergency braking use case. We assess the performance of IEEE 802.11p as well as LTE-V managed mode (mode 3) and unmanaged mode (mode 4) for sidelink communications. The performances are studied in terms of delays, packet error rates (PERs) and functional safety indicators. We first vary the number of vehicles, the surrounding traffic and the inter-vehicle distance. Multiple traffic scenarios are then investigated for the most challenging conditions. We find that for reasonable surrounding traffic, the platoon is generally safe in this emergency scenario, although packet error rates are growing for IEEE 802.11p and LTE-V mode 4 as the traffic intensifies, along with delays for the former technology. Thanks to scheduling, LTE-V mode 3 is not affected by this increasing PER and shows a large constant delay: the scheduling delay. With this study, we pave the way for a further study of these radio technologies with more accurate channel models as well as including new 5G components in our benchmarking.