Swisscom Goes the Other Way – GSM on the Way Out

In a previous post I wrote a bit about UMTS being switched-off in Germany by two network operators in mid-2021, less than a year from now. While other network operators have similar plans I found it quite interesting that Swisscom has decided to do the opposite. Instead of switching-off UMTS soon, they have decided to phase out GSM by the end of 2020.

I find that rather surprising because many operators argue that they rather want to leave GSM running because they still want to support GSM based m2m traffic. I also wonder if indoor penetration of the narrow GSM channels in the 900 MHz band is still superior to anything UMTS or even LTE can do in the same frequency band due to their much larger channel bandwidths? It looks like Swisscom will leave UMTS activated in the 900 MHz band instead of on the 2100 MHz band which will reduce the coverage issue somewhat. And the other benefit of leaving UMTS instead of GSM running is that data services will still work during voice calls. In theory this could also be done in GSM with the Dual Transfer Mode. However, few operators have deployed DTM and even if still used today, throughput is so low that it is more or less useless for most tasks anyway. So there’s good reasons for both options and I don’t see a clear winner here.