Experimental Trials on Sidelink Multi-hop Communications

Cellular vehicle-to-everything (C-V2X) is an emerging technology to realize autonomous driving and Mobility as a Service (MaaS). In C-V2X communications, direct device-todevice communication without passing through the mobile core network, called Sidelink, is employed in vehicle-to-vehicle or vehicle-to-infrastructure communication scenarios. To extend the network coverage and improve the system performance, multihop Sidelink communication has attracted a lot of attention recently. In this paper, the performance of multi-hop communication using V2X Sidelink is evaluated by over-the-air experimental trials conducted in an anechoic chamber. The packet forwarding and routing functions are implemented by software in off-theshelf V2X modules, and the end-to-end latency and the packet reception interval jitter are evaluated. The trial results show that the 99 percentile of the end-to-end latency is less than 100 milliseconds, even with 3 hops.