Power Consumption Optimization in 5G/6G mmWave Networks with User Multi-Connectivity

In the fifth generation (5G) and the upcoming sixth generation (6G) millimeter wave (mmWave) networks, the recent emerging ultra-reliable low-latency (URLLC) applications such as telemedicine and self-driven vehicles require strict availability and reliability requirements. Using user multi-connectivity (i.e., connecting each user to multiple base stations (BSs) simultaneously) has emerged as an efficient solution for providing such high-availability requirements. However, this approach results in higher power consumption over the network, driven by the need to activate larger numbers of BSs. In this paper, we focus on optimizing the power consumption in 5G and beyond mmWave networks, considering four user connectivity levels: quadruple, triple, dual, and single. We propose an adaptable multi-objective integer linear program (ILP) that considers BSs switching on-off and user-multi-connectivity strategies. We compare the network power consumption, the number of switched-off BSs, and the energy efficiency of the four levels of connectivity. The numerical results show that our optimization results in power consumption reduction of 62.6%, 55%, 52.76%, and 52.05% when considering single, dual, triple, and quadruple connectivities, respectively. Moreover, quadruple, triple, and dual connectivity result in more power consumption and less energy efficiency than single connectivity, highlighting the importance of the trade-off between the level of connectivity and the network power consumption. Additionally, the Quadruple connectivity demands 1.5%, 6.8%, and 28.16% more power consumption compared to triple, dual, and single connectivity, respectively.