On the Scalability of the 5G RAN to Support Advanced V2X Services

Cellular networks currently support non-safety-critical Vehicle to Everything (V2X) services with relaxed latency and reliability requirements. 5G introduces novel technologies at the radio, transport and core networks that are expected to significantly reduce the latency and increase the flexibility and reliability of cellular networks. This has raised expectations on the possibility for 5G to support advanced V2X applications, including connected and automated applications such as advanced ADAS services, cooperative driving and remote driving. At the radio access network (RAN), 5G introduces the New Radio (NR) interface that incorporates flexible numerologies and new slot formats, channel coding schemes, and radio resource management processes. Previous studies have reported latency values of 5G NR below 2 ms when considering scenarios with limited users in the cell and with unlimited bandwidth. Supporting advanced V2X services using 5G requires a scalable network capable to support a larger number of users without degrading the required service level in scenarios with potentially limited spectrum. This study advances the current state of the art with the evaluation of the scalability of the 5G NR RAN. As a case study, the paper evaluates the capacity of 5G RAN to support the latency and reliability requirements of the cooperative lane change use case as the network load varies. The results show that the capacity of the 5G RAN to support advanced V2X services depends on the system configuration, network load and service requirements. These results call for a careful design, configuration and planning of 5G networks to support V2X services.UMH work was supported in part by the Spanish Ministry of Science and Innovation (MCI), AEI and FEDER funds under Project TEC2017-88612-R, and the Ministry of Universities (IJC2018-036862-I)

Analysis of 5G RAN Configuration to Support Advanced V2X Services

5G offers high flexibility at the radio, transport and core networks to support various services of critical verticals such as connected and automated driving. At the Radio Access Network (RAN), 5G defines a New Radio (NR). 5G NR utilizes different subcarrier spacing, slot durations, modulations and channel coding schemes. This flexibility offers the possibility to support automotive services with different and demanding requirements, such as Advanced Driver-Assistance System (ADAS), cooperative driving, and remote driving. Previous studies showed that 5G NR can be configured to achieve latencies below 2 ms. However, existing studies are generally restricted to scenarios with a limited number of users and unlimited bandwidth. Therefore, it is important to analyze whether 5G NR can effectively support these services as the network scales under limited spectrum allocations. This study advances the current state of the art to demonstrate that the capability of 5G NR RAN to support advanced V2X services depends on the RAN configuration (subcarrier spacing, slot duration and error protection) and network loadUMH work was supported in part by the Spanish Ministry of Science and Innovation (MCI), AEI and FEDER funds under Project TEC2017-88612-R,and the Ministry of Universities (IJC2018-036862-I), and the Generalitat Valencian

V2X Communications for Maneuver Coordination in Connected Automated Driving: Message Generation Rules

Connected automated vehicles (CAVs) can use vehicle-to-everything (V2X) communications to exchange their driving intentions and coordinate their maneuvers. Message generation rules are necessary to decide when and how maneuver coordination messages (MCMs) should be generated. The design of these generation rules must consider the critical nature of maneuver coordination and the limited bandwidth available for V2X communications. This study proposes the first two sets of V2X message generation rules for maneuver coordination between CAVs. The Risk proposal increases the rate at which vehicles generate MCMs when vehicles detect a potential safety risk. With the Tracking Trajectories proposal, vehicles generate a new maneuver coordination message when they significantly modify their planned trajectory. For both proposals, the messages include the planned and possible desired trajectories of the ego vehicle. The evaluation shows that the proposed generation rules efficiently support maneuver coordination and offer a balance between more frequent updates of the driving intentions of CAVs and lower coordination time and better control of the V2X communications channel load. This study also reveals that congestion control protocols can significantly impact maneuver coordination