On the Flexible and Performance-Enhanced Radio Resource Control for 5G NR networks

The RRC machinery of 5G NR introduced a new RRC state, RRC Inactive, which enables to suspend and quickly resume a radio connection, thus reducing the delay and network signalling needed for connection establishment, which in turn reduces the UE battery consumption. This paper describes the design of the RRC Inactive state and analyses how it can be efficiently used in conjunction with DRX, under different traffic profiles.The aim of this study is to investigate the trade-off between latency, network signalling, and UE battery consumption to enable the envisioned wide range of services over 5G networks, comprising massive MTC, in the most flexible and efficient way. The simulation carried out in a dense urban macro scenario reveals that, adopting an optimal configuration of RRC Inactive state results in more than 200% latency reduction compared to RRC Idle and around 40% UE power saving compared to RRC Connected, under infrequent traffic. The results also confirm that with more frequent traffic it is more beneficial to maintain the UEs in RRC Connected state avoiding any state switching cost.