It's part of a new space race to bring Web access to the entire planet.
The government said in a lawsuit that the companies had illegally shared ad sales data in violation of antitrust law.
Comcast is "a much greater threat" than AT&T-Time Warner, the American Cable Association claims.
Dish blames the blackout on AT&T's merger with Time Warner, but the telecom giant says it has nothing to do with the situation.
Voatz, the start-up behind the pilot, says its system is secure. But election integrity experts say the technology remains potentially vulnerable.
The appeal brought by the telecom industry challenged federal rules that were against the blocking or slowing down of websites.
The government has been looking into the matter for months.
Supporters say so-called 'stablecoins' may fulfill much of bitcoin's original promise.
The move is a blow to Internet activists who sought tougher state rules.