Another day, another little trace session in the London tube when coming home from a event in the evening at 9 pm. In Part 2 of this series I’ve taken a look at one network operator’s LTE/5G coverage on London’s Central underground line and came away quite impressed. 5G NR n78 on the platforms with massive bandwidth, and 5G NR n8 together with LTE in the tunnels. From what I can tell by press reports, the cellular network is deployed by a 3rd party company, so there was the odd chance that all network operators would use the same spectrum. This would of course significantly limit the capacity. So I decided to have another look with a SIM card of a different operator.
It turned out that this operator has a similar approach as the other operator I had a look at in the previous post, and also deploys 5G NR n78 together with LTE band 1 as an ENDC anchor on platforms. Instead of 50 + 40 MHz non-contiguous 5G CA, however, they are using their 80 MHz channel in the n78 band. Inside tunnels, they are also using LTE band 1 as anchor, but 5G band n28 (700 MHz) instead of band n8 (900 MHz) like the other network operator. Also, throughput on the platforms was well over 400 Mbps and inside tunnels, I could still get high double digit megabits per second in the downlink direction. But this was of course at night. Next time, I’ll have another look during daytime to see how the network performs under load.