Opensignal just released a new report on the performance of U.S. wireless networks. The report ranks major U.S. networks in five categories based on crowdsourced data:

4G availability

Video experience

Download speed experience

Upload speed experience

Latency experience

Verizon took the top spot for 4G availability and video experience. T-Mobile came out on top for both of the speed metrics. T-Mobile and AT&T shared the top placement for the latency experience metric.

Selection bias

I’ve previously raised concerns about selection bias in Opensignal’s data collection methodology. Opensignal crowdsources data from typical users. Crowdsourcing introduces issues since there are systematic differences between the typical users of different networks. Imagine that Network A has far more extensive coverage in rural areas than Network B. It stands to reason that Network A likely has more subscribers in rural areas than Network B. Lots of attributes of subscribers vary in similar ways between networks. E.g., expensive networks likely have subscribers that are wealthier.

Analyses of crowdsourced data can capture both (a) genuine differences in network performance and (b) differences in how subscribers on each network use their devices. Opensignal’s national results shouldn’t be taken too seriously unless Opensignal can make a compelling argument that either (a) its methodology doesn’t lead to serious selection bias or (b) it’s able to adequately adjust for the bias.

Speed metrics

Opensignal ranks carriers based on average download and upload speeds. In my opinion, average speeds are overrated. The portion of time where speeds are good enough is much more important than the average speed a service offers.

Opensignal’s average download speed results are awfully similar between carriers:

Verizon – 22.9 Mbps

T-Mobile – 23.6 Mbps

AT&T – 22.5 Mbps

Sprint – 19.2 Mbps

Service at any of those speeds would be sufficient for almost any activities people typically use their phones for. Without information about how often speeds were especially low on each network, it’s hard to come to conclusions about differences in the actual experience on each network.