A new study finds that wireless carriers continue to cramp the resolution of streaming video, and they do so unevenly and often unnecessarily, as their bandwidth routinely exceeds speeds necessary for high-definition streaming.
“We find different network providers using different rate limits (e.g., 1.5 Mbps and 4 Mbps) and targeting a different set of apps (e.g., YouTube vs. Netflix),” summed up the paper titled “A Large-Scale Analysis of Deployed Traffic Differentiation Practices.”
Perhaps the carriers engage in this unnecessary throttling because customers have become so accustomed to it that it doesn't affect their behavior.
The study by researchers David Choffnes, Fangfan Li and Alan Mislove of Northeastern University as well as Phillipa Gill and Arian Akhavan Niaki of the University of Massachusetts Amherst collected 1,045,413 measurements generated by that group’s Wehe app for Android and iOS on the instruction of 126,249 users using 2,735 ISPs in more than 180 countries.
The app compared how those providers treated video from YouTube, Netflix, Amazon Prime Video, NBC Sports, Vimeo, Spotify, and Skype and found 30 providers in seven countries engaged in at least some throttling--including all four U.S. carriers.
But the big four didn’t practice this uniformly. A table on the report shows that while AT&T, Sprint, T-Mobile and Verizon all throttle Netflix and YouTube, AT&T left Netflix alone and everyone but T-Mobile let Vimeo stream unimpeded.
The study cross-checked streaming performance by using virtual-private-network services to cloak the identity of these streaming sites and found that all four carriers “support much higher throughput than the throttling rate.”
The study further detected that Amazon and Netflix’s mobile apps constrained their own resolution to a level well below the 480p limits advertised by the big four carriers.
In 2016, Netflix admitted to cutting back the resolution of its own mobile streams to protect users from data caps; at the time, AT&T pronounced itself “outraged” by the practice.
Wave7 Research lead analyst Jeff Moore suggested these findings and earlier coverage of video throttling would not change subscriber behavior—for now.
“Video compression by carriers is not a major factor in consumers’ choices of carriers and plans,” he wrote in an email. “However, several factors are converging that could change this to a small degree”—in particular, higher video viewing by younger compression and carrier plans that offer different levels of throttling, such as those just introduced by Verizon.
(Disclosure: This post’s author also writes for Yahoo Finance, a Verizon media property.)