  In vehicle-to-everything (V2X) communications, reliability is one of the most
important performance metrics in safety-critical applications such as advanced
driving, remote driving, and vehicle platooning. In this paper, the link
reliability of unicast concurrent transmission in mode 1 (centralized mode) of
5G New Radio based V2X (NR-V2X) is analyzed. The closed-form expression of link
reliability for concurrent unicast transmission is firstly derived for a
highway scenario under a given interference distance distribution. On this
basis, according to the macroscopic configuration of the system, a method to
control the number of concurrent transmission nodes is proposed, including the
communication range, message packet size, and the number of lanes, etc. The
results indicate that the proposed method can maximize the system load on the
premise of satisfying the link reliability requirements.
