When I had my first Three phone in late 2005, they had an agreement which let them use ALL of the other networks’ 2G capacity. I cannot remember when those agreements expired, but it became very difficult to sustain calls when the local 3 masts had any problems.
They had a unique USIM which gave ‘video’ calls but didn’t work in other ‘unlocked’ phones. I didn’t really understand the technology involved, but it must have had something to do with bandwidths supported or software?
🤡
