Comcast will be launching a new streaming or WebTV service for Xfinity customers. For only $15 a month, customers will get access to live TV from all broadcast  networks such as NBC, Fox and HBO.

Clearly, it's competing with others such as HBO, Showtime, Dish and Sony in selling cable TV channels over the web that have been surfacing and spreading out toward customers within the past three years.

This new service, called Stream, will allow subscribers to access the content of its library on computers and mobile devices while at home, as reported by The Next Web. Movies on-demand, cloud-based DVR service and TV everywhere are also included in the subscription.

Take note: The shows for this subscription could not be watched on television, and they cannot be taken outside homes, contrary to the movies on-demand which can be watched "away" or "at home."

As stipulated, it works on mobile devices, which means broadband Internet is needed. This is true for every Web TV service, according to Record.

Comcast is planning to sell this to only 23 million people who havet Internet service, making it an add-on (not a package bundle) to an existing Comcast broadband subscription.

Whether Comcast's Stream could take down Sling TV (20 channels for $20 a month, with add-ons available at $5) and PlayStation Vue (for 50 channels at $49.99) is yet to be seen.

The beta will roll out in Boston by the end of summer, Slash Gear has learned. Then, it will expand to Chicago and Seattle.

HBO is actually the only premium cable network included in Stream. That's definitely good news for "Games of Thrones" fans out there.

The company is hoping that the service will be available across the United States by 2016.

Streaming services are being more mainstream as people shift toward Internet-based media for their entertainment needs.