Multi-connectivity in 5G and Beyond

Full title—Online Control of Traffic Split and Distributed Cell Group State Decisions for Multi-connectivity in 5G and Beyond

The emergence of new radios (NRs) including mmWave in 5G necessitates multi-connectivity to enable a robust control plane as well as a faster user plane to satisfy stringent mobile service requirements.

In multi-connectivity, a mobile user equipment (UE) communicates with multiple base stations simultaneously, where each base station provides a cell group as radio resources to the UE. In this paper, we design an online control policy for downlink transmission in a multi-connectivity environment. Incoming traffic is split across multiple base stations, and each base station determines each cell group’s state. As design constraints, traffic splitting and cell group state decisions can only be performed in certain cases.

Furthermore, cell group state control should be implemented in a distributed manner between base stations. Designing control policies that meet these constraints poses significant challenges. By applying the Lyapunov optimization method, we develop a joint control algorithm for real-time traffic splitting and cell group state decisions to satisfy the imposed constraints.

Our proposed algorithms are robust and simple enough to be implemented in a real network. We confirm through analysis and simulation that our algorithm achieves optimal performance and outperforms other competitive schemes in terms of the balance between power consumption and queue length.

Full Article: IEEE Transactions on Vehicular Technology, December 2021, Early Access