Recently, some engineers at Georgia Tech undertook a detailed analysis of broadband performance — studying in particular the concept of "Traffic Shaping."
The Georgia Tech paper talks about something called "PowerBoost™," of which I was a co-inventor in 2003. PowerBoost is a tool that cable companies have deployed that lets our high-speed Internet customers dynamically tap into excess capacity in the DOCSIS network. In other words, a subscriber to a specific speed-tier (e.g. our Performance 12 Mbps tier) can attain significantly higher speeds for periods of time whenever excess network capacity is available.
As Georgia Tech points out, PowerBoost "[allows] a user to exceed the service rate that he/she paid for, for a limited burst size," and "is marketed as a free service enhancement." The researchers specifically measured Comcast's PowerBoost performance, using the ShaperProbe tool hosted by an organization called Measurement Lab. You can see the results summarized below (and detailed here):
There are a number of observations you can take away from Georgia Tech's independent analysis:
PowerBoost significantly increases a customer's speed performance - at least 56% higher, according to the ShaperProbe testing.
Comcast customers frequently have access to higher PowerBoost speeds. In fact, the Georgia Tech paper indicates that Comcast customers see PowerBoost speeds in the downstream about 73.5% of the time, and in the upstream about 71.5% of the time. And these results are similar to the performance characteristics of other cable operators utilizing PowerBoost.
PowerBoost speeds tend to last tens of seconds at a time, not just one or two seconds. This demonstrates that Powerboost provides significant acceleration of digital media downloads and uploads, including rapidly filling playback buffers for streaming video services.
The Georgia Tech researchers aren't the only ones who have noticed the benefits of PowerBoost. As we have noted, the FCC's recent analysis of broadband performance in the U.S. found that cable companies that use PowerBoost "consistently exceed 100 percent of advertised speeds across all speed tiers.....achieving as high as 152 percent of advertised speed..."
The recent research at Georgia Tech and the FCC make clear that PowerBoost is a great tool not only for improving our customers' online experience but also for making more efficient use of our broadband networks. We will keep on investing and innovating to provide more broadband speed to more Americans than any other company.