Saving Energy in Cellular Networks with National Roaming: A Data-Driven Analysis

Ensuring reliable and ubiquitous mobile network coverage is critical for user experience and competitiveness of mobile network operators (MNOs). To meet varying service demands, MNOs typically over-provision their infrastructure, leading to an increased energy consumption and operational costs. National roaming (NR), a form of cooperation between MNOs, enables infrastructure sharing to reduce redundancy in network infrastructure and improve efficiency by allowing each mobile user to be connected to a base station that provides the best connectivity irrespective of which MNO the user is subscribed to. In this paper, we analyse real-world data from three Dutch municipalities to assess NR’s impact on operational power consumption as well as coverage and throughput relative to the current de-facto operation mode where MNOs operate in an isolated way with no cooperation (NC). We propose an energy-aware user association scheme (EA) with polynomial complexity for the studied NR scenario and compare it to a load-balancing, energy-oblivious alternative. Our results show that NR can reduce power consumption in the radio access network by up to 30%, reduce the fraction of disconnected population (FDP) by 95%, and raise the fraction of satisfied population (FSP) by 50%. Our analysis suggests that energy savings are most significant in dense, overprovisioned networks, while FDP and FSP gains are most notable in sparse deployments. Moreover, we observe that EA outperforms our comparison baseline for both NR and NC scenarios, which implies that current MNOs can decrease their power consumption significantly by following an energy-aware user association scheme that facilitates putting some more BSs in sleep mode without compromising FDP and FSP.