Network infrastructure sharing models fall into two main categories: passive sharing (sharing the site, tower, antennas and feeder cables) and active sharing (sharing of electronic equipment such as switches and sometimes spectrum).
Passive site sharing refers to the sharing of non-active equipment. The potential advantages with passive sharing are that costs are shared for the acquisition of sites, for infrastructure, lease, maintenance and power. With passive site sharing, each operator maintains their own core network, backhaul and radios, but they share the sites, towers, power, antennas, feeders, HVAC and security.
Passive backhaul sharing is similar to passive site sharing, but the mobile network operators (MNOs) also share the backhaul links (the connection from the wireless cell tower to the core network). There are obvious advantages in equipment costs with passive backhaul sharing, plus big savings to be made in deployment. Passive backhaul sharing results in reduced license fees for microwave links and because 70-80 percent of costs come from the digging of trenches, these costs can be significantly reduced for all infrastructure sharing participants.