5G New Radio (NR) has been a great success story since its introduction. It offers high reliability, low communication latency, flexibility, and efficiency that further enable 5G networks to be used for mission critical applications. Currently, there are specialized networks serving industry verticals that would benefit from the NR properties. Key use cases include communications for critical infrastructure such as railways, public safety, and smart energy and infrastructure. These networks often use dedicated spectrum allocations that are narrower than the original minimum operating bandwidth of NR. In this paper, we describe how new flexibility is being introduced into the NR design to allow operation with bandwidths between about 3 and 5 MHz. As a use case study, we focus on railway communications, and study the co-existence of the Global System for Mobile Communications–Railway (GSM-R) and Future Railway Mobile Communication System (FRMCS) based on NR during the decade-long migration period. We discuss the changes required for the NR control channels and signaling and study the effect of the changes on the system performance.

The efficient usage of power has become a matter of extreme importance in 5G New Radio. To enhance UE power saving, among other techniques of the 3GPP release 17, it is worth mentioning the relaxation of the measurements required for RLM (Radio Link Monitoring) and BFD (Beam Failure Detection). In this paper, we describe the design of the RLM and BFD measurements relaxation framework and evaluate the power saving gain provided by such relaxation for UEs in low mobility, at cell center and with a short DRX cycle. Our results show that the attainable power saving gain can be approximately between 5% and 40%. The gain greatly depends on factors such as the applied relaxation level, location in time of the reference signals used for the measurements, DRX configuration and whether the UE is also allowed to relax other measurement types (e.g. Radio Resource Management measurements). Furthermore, we study the impact of such relaxation on the mobility and QoS performance through numerical analysis. We conclude that the performance degradation due to relaxation can be bounded to acceptable levels if the applied relaxation level is limited and the UE is able to stop employing relaxation timely, whenever the radio quality deteriorates.