Currently the advent of 5G technology, offering higher data rates, stricter latency requirements, and increased connectivity, is posing relevant challenges to the deployment of future communication networks. As traffic volumes increase, concerns regarding the energy consumption and efficiency of base station infrastructure in mobile access networks grow. These infrastructures are typically designed to meet peak demands, but they may remain underutilized for most of the time, resulting in significant energy waste and financial costs. This thesis addresses these challenges by proposing a novel strategy called network sharing (NS), in which two or more mobile network operators (MNOs) accept to share their own radio access network (RAN) infrastructure, coming to an agreement to collaboratively utilize portions of it to serve their customers.