Comcast just launched Stream TV, its live streaming TV service, in the Chicago and Boston areas (including eastern Massachusetts, New Hampshire and Maine), and plans to debut the service in all its territories by early 2016. What makes Stream TV of interest is that its usage does not count against the 300GB data plans available in some Comcast territories or use a customer’s Internet bandwidth measured in bits per second. Stream TV is an IP cable service delivered over Comcast’s managed network rather than the public Internet.

According to Ars Technica, the launch comes as Comcast gained 320,000 broadband subscribers and lost 48,000 cable TV subscribers. In Q3 2015, Comcast had a total of 22.87 million Internet subscribers and 22.26 million cable TV subscribers.

Stream TV, which costs $15 a month, is aimed at Comcast’s Internet-only customers, with in-home streaming video working “similarly to cable TV — despite not requiring a cable TV subscription or set-top box.” It offers live programming from HBO, ABC, CBS, CW, Fox, NBC, PBS, Telemundo, Univision and some local channels.

Ars Technica wondered if the potentially better video quality would provoke dissent from streaming competitors. “There is no specific rule preventing an Internet service provider from exempting its own streaming video from data caps,” but the FCC’s net neutrality rules “allow for complaints against so-called zero-rating schemes,” which will be judged on a case-by-case basis.

Neither the FCC nor Netflix, a competitor potentially impacted by Stream TV, would comment. When it bought NBCUniversal, Comcast signed an agreement that, if it offers capped Internet service, it won’t treat its own traffic differently from that of rivals. That does not apply to Stream TV, which doesn’t travel over the public Internet.

Related:
Comcast May Have Found a Major Net Neutrality Loophole, Wired, 11/20/15