Highly Efficient Relay Routing Method for 5G Cellular V2V Communications

C-V2X (Cellular-Vehicle-to-Everything) is a radio communication system, standardized in 3GPP, for connecting vehicles. In particular, V2X using 5G New Radio (NR), standardized since Release 16, is examined to set up multiple Base Stations (BSs) for securing a wide communication area. However, practical and cost issues are associated with installing many BSs for V2X. Sidelink communication, which is a direct V2V (Vehicle-to-Vehicle) communication between the user equipment (UEs) aids in further expanding the communication area without increasing the BSs, and configures a relay route between the UEs via the BS and roadside unit (RSU). However, as no relay route construction method using the 5G NR control data exists, there is no evaluation of V2V communication’s transmission characteristics using the relay routing method. This study proposes a new relay routing scheme for 5G NR V2V wherein an effective distance based on the quality of communication among the BSs, RSUs, and terminals is provided. Moreover, a relay node for realizing a path with minimal number of frames required for end-to-end (E2E) communication from the source to the destination node is selected. The transmission characteristics of the proposed method were evaluated and verified in the 3GPP environment, where a packet reception ratio of 0.9 was achieved even when the number of BS to be installed was reduced by 1/6.