Energy consumption is among the major problems faced by cellular operators. In metropolitan areas, cellular network is divided into smaller cells due to high traffic. During low traffic period e.g., at midnight, Base Stations are underutilized but remain active and consume energy. In this paper, we propose two signaling frameworks for pooling the Base Stations of different cellular operators in a single cell during low traffic. The first Framework can be deployed rapidly with existing infrastructure. While the second framework can be used with Base Stations with enhanced capabilities. We consider cellular network with real Base Stations location in Paris region. We have taken blocking probability as Quality of Service parameter. Proposed signaling frameworks take into account call processing, subscribers soft handover between different operator's Base Station. In this way, up to 66% energy saving can be achieved for three different service providers in a single cell at low traffic period which also helps in the reduction of cellular radiation.