In 2022 DB/Neovendi together with Thales France (now Hitachi) conducted field tests with the Adaptable Communication System (ACS) on DB’s test track in Scheibenberg (Ore Mountains in Saxony). This was part of the X2Rail-5 WP3 activities, a European Shift2Rail project (see https://projects.shift2rail.org/s2r_ip2_n.aspx?p=X2RAIL-5). The goal of the ACS is to allow bearer switching, the seamless handover between different mobile telecoms networks. The idea is to be able to increase the availability of railway applications in case of network coverage issues. For examples, if the GSM-is not available the system can switch to a public mobile operator’s 4G or 5G network without impact on the application. The system consists of a track side and an on-board system. In order to not only measure but also visualise the quality of the handover, video was used as an application (a camera filmed the surrounding area). The impact on ETCS and voice was also tested. The networks available at the DB test track were Edge from Vodafone (used to simulate GSM-R), a private 5G SA (Stand Alone) network from DB in the middle of the 24 km track and 4G as well as 5G NSA (Non Stand Alone) networks from Vodafone and Deutsche Telekom. The project showed that the ACS could support bearer switching between all networks including the handover from private 5G SA to public 5G NSA networks.