On Optimal Infrastructure Sharing Strategies in Mobile Radio Networks

The rapid evolution of mobile radio network technologies poses severe technical and economical challenges to Mobile Network Operators (MNOs); on the economical side, the continuous roll-out of technology updates is highly expensive, which may lead to the extreme where offering advanced mobile services becomes no longer affordable for MNOs which thus are not incentivized to innovate. Mobile infrastructure sharing among MNOs becomes then an important building block to lower the required per-MNO investment cost involved in the technology roll-out and management phases. We focus on a Radio Access Network (RAN) sharing situation where multiple MNOs with a consolidated network infrastructure coexist in a given set of geographical areas; the MNOs have then to decide if it is profitable to upgrade their RAN technology by deploying additional small-cell base stations and whether to share the investment (and the deployed infrastructure) of the new small-cells with other operators. We address such strategic problem by giving a mathematical framework for the RAN infrastructure sharing problem which returns the "best" infrastructure sharing strategies for operators (coalitions and network configuration) when varying techno-economic parameters such as the achievable throughput in different sharing configurations and the pricing models for the service offered to the users. The proposed formulation is then leveraged to analyze the impact of the aforementioned parameters/input in a realistic mobile network environment based on LTE technology.