Study of the Collision Resolution Method in New Radio Unlicensed Networks with Multichannel Access of Type A

New Radio Unlicensed (NR-U), a fifth-generation cellular communication technology, allows base stations to use multichannel transmissions in the unlicensed frequency band, which is of great practical interest. However, the simultaneous operation of several NR-U operators in the same frequency channels leads to an increase in the number of collisions in the network when gaining access to an unlicensed channel. In this paper, we study the effectiveness of the collision resolution method previously proposed for single-channel transmissions when base stations use the multi-channel access method of access of Type A defined in the NR-U specification. Scenarios of coexistence of two NR-U operators with a various choice of active channels are considered. The normalized network throughput and the uniformity of the distribution of channel resources between the base stations of operators are estimated. It is shown that the use of the collision resolution method makes it possible to increase the total throughput by up to 20% compared to the standard method.