US Telco Support > AT&T > AT&T U-verse > Review AT&T U-Verse

reply to justin

Re: Review AT&T U-Verse

There's a lot of chatter about Dish HD quality better than U-Verse. Its not clear to me how that is possible unless it is simply broadcast in lesser format (e.g. 1080i vs p vs 780i or p). Does anyone have the facts?

We get approx 170 HD channels on Dish which far surpasses the approx 50 on U-Verse, but I suppose they'll keep adding.

Both U-Verse and Dish use MPEG-4 compression.

There's a lot more to it than just broadcast format.

U-verse has a 25mbps pipe to the home, that also has to carry up to 10mbps internet. AT&T is not currently doing any "mixed-use" of their streams, I've personally tested that I get my full 10mbps when I'm using all 4 streams.

So, that leaves 15mbps for TV. Within that 15mbps, they fit 2 HD and 2 SD TV streams. I have yet to see hard facts about their HD data rates, but you can do a little calculating. They advertise that their DVR holds 133 hours of SD and 37 hours of HD. That means HD streams are 3.6x the size of the SD streams.

So:

x + x + 3.6x + 3.6x = 15
x(1+1+3.6+3.6) = 15
x = 15 / 9.2
x = 1.63

Using these calculations, SD is 1.63mbps and HD streams are 5.86mbps.

For comaprison, someone posted the file sizes for shows captured from their DISHnetwork box at MPEG-4. Their recorded "Battlestar Galactica" in HD was at 7.7mbps. Their local MPEG-4 NBC was a whopping 11.2mbps!

So, given that Dish is delivering higher MPEG-4 data rates, it's easy to see why they might have better picture quality. Interestingly, the most common complaint about U-verse is not breakup during high action scenes, but rather a "stepping" motion in the background of practically still video. Seems like that's something that could be improved in the compression algorithms.