Recently, I’ve been on a two week skiing trip in Bad Gastein, a small village in the Austrian alps. As usual and also because my default cellular connectivity did not meet my needs, I had a closer look at the local connectivity options and gained some interesting insights.
For testing purposes and of course for redundancy, I have subscriptions of two premium mobile network operators in Germany, and both usually also provide excellent service while roaming. During the day, LTE data rates in the automatically selected roaming network were well beyond 100 Mbps in the downlink and well over 80 Mbps in the uplink. 5G was not yet available on the local cell tower, but at those data rates, I didn’t really mind. In the evenings, however, the automatically selected network got more and more loaded, and by 8 pm, downlink speeds consistently slowed to 1-2 Mbps. Also, round trip times increased from 100 ms to well over 200 ms. In the uplink direction, however, I still got 50 Mbps. A clear sign of congestion and totally unusable for many things.
Bad Gastein is a small town, but a major tourist destination in Austria, so I was a bit surprised. I then had a look at how much capacity was actually rolled out in that network and was disappointed to only see LTE bands 3 and 1 active at that site. With such a configuration, it’s no wonder the site gets congested in the evening with thousands of tourists in town. So I switched to manual network selection to have a look if I could get a better service on one of the other cellular networks. To my great dismay, the two other networks on air were barred from roaming, I consistently got reject causes #17 and #15 to force me back into the only network that seems to have been selected for roaming by my home network operator.
Fortunately, I could switch over to the SIM card of my second home network operator, which seems to have had a different roaming setup with Austrian network operators. With this SIM card in the other SIM slot, I could also roam to one of the another local mobile networks. Here, the situation looked entirely different. Instead of two meager LTE carriers, they had a 100 MHz 5G n78 carrier on air and 3 LTE carriers on top. With this deployment, I could still get well beyond 100 Mbps in the downlink direction during evening hours and 40+ Mbps in the uplink direction. It’s a prime example of how the 5G n78 band in the 3.5 GHz range helps to keep ahead of the rising bandwidth requirements of customers.
Side note 1: For most people, the 10 Mbps down / 5 Mbps up performance of the hotel’s Wi-Fi network will probably do. As it was consistent throughout the day and only reduced to about half these values in the evening, they most likely apply bandwidth limits per device. Usable, but not ideal, as every now and then I’d like to transmit a few GB at a time, for which such speeds are obviously not sufficient.
Side note 2: In the second week, I could suddenly roam to that n78 network with my both SIM cards again. From an end user point of view, it’s unfortunately not possible to tell blocking two of the three available roaming networks was a commercial decision or a network problem. In any case, I was glad I had my personal redundancy.