Balancing Latency and Energy Efficiency in mmWave 5G NR Systems With Multiconnectivity

Abstract

Multiconnectivity is a vital option in 5G New Radio (NR) systems allowing user equipment (UE) to maintain multiple links to nearby base stations (BS) improving service reliability. However, this functionality is very power-hungry prohibiting its application in practice. To alleviate this shortcoming discontinuous reception (DRX) mechanism can be utilized. The latter requires careful parameterization as it may drastically increase latency at the air interface. In this letter, we develop a mathematical model to characterize the trade-off between energy efficiency and latency in millimeter wave (mmWave) 5G NR systems under micromobility and blockage impairments. We then utilize it to determine the optimal type of DRX timers scaling. We show that micromobility has a positive impact on energy efficiency. For low micromobility speeds (<0.2°/s) proportional DRX scaling scheme with the scaling coefficient <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$k &lt; 1.0$ </tex-math></inline-formula> , provides the best performance in terms of considered metrics while for higher speeds it leads to a compromise between them. The optimal value of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$k$ </tex-math></inline-formula> depends on design preferences.