You're sitting in a coffee shop, your eyeballs glued to the phone. YouTube is open, and you're waiting for the latest comic-book movie trailer to load. Instead, you get the oh-so-familiar circular loading icon instead.
And it keeps spinning and spinning.
It's at these moments that you wonder if the time has come to switch wireless carriers. But which carrier? Each of them claims to be some variation of fastest, most reliable or even newest. It's tough to cut through the noise.
Testing firm OpenSignal has some answers, with a surprising contest for the top spot.
T-Mobile earned top honors in the firm's first US-dedicated report, released Tuesday. It took home awards for the speed and responsiveness of its 3G network. Verizon won for 4G coverage, and both carriers shared 4G speed honors.
AT&T, the nation's second-largest carrier, walked away with no awards, while Sprint won for the responsiveness of its 4G network.
These tests are increasingly critical as consumers get more discerning about which service they sign up for, with every carrier offering some discount or promotion to lure them over. The results also form the basis for a torrent of advertising as the carriers play up their finest bragging point.
OpenSignal collects its data from regular people who download its app, similar to Speedtest.net by Ookla, and for this study boasted more than 180,000 participants. That's in contrast to data collected from drive tests, in which firms send out drivers to monitor devices using different networks, such as the studies done by RootMetrics.
T-Mobile's network tested at an average speed of 12.3 megabits per second, just above the 12 megabits-per-second speed offered by Verizon's. But because of the slight difference, OpenSignal declared it a statistical dead heat and gave each the 4G speed award. The firm noted that T-Mobile "barely edged out" Verizon in the 11 largest cities.
"The key here is that the past year has been the year of coverage growth for us," said a T-Mobile spokeswoman.
Verizon, meanwhile, downplayed the methodology of the test. "Studies that use crowd-sourced data sound cool, but they can easily be misleading -- when you can't reliably connect to a network, there's no way to measure its performance or speed," said a spokesman.
Sprint pointed to another study performed by Nielsen that showed it delivered the highest speeds. "We'll keep working hard to be provide the best experience for our customers, but we also know that network performance differences are often indiscernible to most customers in most markets," the company said.
A spokesman for AT&T wasn't available for comment.
These are average figures based on a sampling of data, so coverage and speed will vary depending on where you live.
Overall, OpenSignal also concluded that the US carriers had lost their edge around the world, with many overseas service providers offering faster networks. "The US is falling far behind globally in LTE speed," the study said.
The average speed in the US is 9.9 megabits per second, while many other countries offer a consistent connection at twice the speed.
Updated at 4:44 a.m. PT: To include a comment from T-Mobile, Sprint and Verizon.