Performance evaluation of bandwidth reservation for mmWave in 5G NR systems
Keywords:
millimeter wave, 5G networks, New Radio, session continuity, bandwidth reservation, new session drop probability, ongoing session drop probability, system resource utilizationAbstract
Introduction: In 3GPP New Radio (NR) systems, frequent radio propagation path blockages can lead to the disconnection of ongoing
sessions already accepted into the system, reducing the quality of service in the network. Controlling access to system resource by
prioritizing for the ongoing sessions can increase the session continuity. In this paper, we propose resource allocation with a reservation
mechanism. Purpose: Development of a mathematical model for analyzing the effect of this mechanism on other system performance
indicators – dropping probabilities for new and ongoing sessions and system utilization. The model takes into account the key features
of the 3GPP NR technology, including the height of the interacting objects, the spatial distribution and mobility of the blockers, as well
as the line-of-sight propagation properties between the transceivers for mmWave NR technology. Results: We analyzed the reservation
mechanism with the help of a developed model in the form of a resource queueing system with signals, where the base station bandwidth
corresponds to the resource, and the signals model a change in the line-of-sight conditions between the receiving and transmitting
devices. Creating a priority for ongoing sessions whose service has not yet been completed provides a considerable flexibility for
balancing the session continuity and dropping of a new session, with a slight decrease in the efficiency of the radio resource utility. With
the developed model, we showed that reserving even a small bandwidth (less than 10% of the total resources) to maintain the ongoing
sessions has a positive effect on their continuity, as it increases the probability of their successful completion. Practical relevance:
The proposed mechanism works more efficiently in overload conditions and with sessions which have a high data transfer rate
requirements. This increases the demand for the proposed mechanism in 5G NR communication systems.