Swiss operators Salt and Sunrise are preparing to significantly expand their existing mobile network-sharing relationship, with the companies planning to assess broader use of multi-operator core network (MOCN) technology across rural and less densely populated parts of Switzerland.
The operators announced today that they have signed a memorandum of understanding (MoU) covering a planning and technical study to determine whether their existing cooperation at selected mobile sites can be extended. The objective is to improve coverage and network quality while reducing the cost and duplication associated with operating separate networks in areas with relatively few mobile users.
The companies have not disclosed how many sites could ultimately be included or what proportion of their rural networks might eventually be shared, but the proposal does go beyond passive infrastructure sharing. Salt and Sunrise say the focus will be on closer cooperation in the Radio Access Network (RAN) using a form of the architecture known as Multi Operator Core Network (MOCN). Under this model, the same radio units can be connected to both operators’ core networks, allowing customers of each operator to use parts of the other’s RAN.
The companies say the arrangement could give customers in rural areas access to a broader range of mobile sites, improving coverage, reception and reliability. Approximately 70% of their combined mobile-network sites are located in medium-density and rural areas, while more than half of Switzerland’s population also lives outside urban centres, according to the companies.
A recent OpenSignal report places both operators behind Swisscom on its coverage experience metrics, exposing at least some of the motivation to expand sharing.
In Switzerland, operators are moving decisively towards 4G and 5G networks, with Sunrise having shut down its 3G network in 2025 and Salt planning to retain 3G only until the end of 2026. That creates an opportunity to reconsider how radio infrastructure is deployed as older technologies are switched off and spectrum and sites are repurposed for newer networks.
A specific limitation in Switzerland is the country’s limitation on transit power levels, which can benefit those operators with lower spectrum bands. Salt and Sunrise are affected in-market by a very unequal spectrum holding share, with Swisscom holding far more spectrum than its two rivals. At 700 MHz, Salt has a useful 20 MHz block in the 700 MHz band, while Sunrise has only a 10 Mhz block. Swisscom has 30 MHz as well as a 5 MHz supplemental downlink block
When it works well, network sharing separates the part of the network where greater cooperation can deliver economies of scale – the RAN – from the parts of the business where they compete. Rather than each operator maintaining separate radio infrastructure at every location, a shared RAN can serve subscribers from both networks while the operators retain their individual cores.
Salt and Sunrise already have experience with this model, having first started network sharing in 2014 with a framework agreement for passive sharing at antenna-site locations, alongside a limited active network-sharing pilot with Salt. Today’s MoU provides a framework for examining whether that cooperation can be extended more systematically across rural and less densely populated areas.
The initiative also reflects a broader economic problem facing mobile operators. Rural networks can be expensive to build and operate because substantial infrastructure is required to cover large geographic areas, while the number of customers generating revenue from individual sites can be relatively small.
