As T-Mobile works to convince regulators to OK its proposed merger with Sprint, the company is revealing more details about its upcoming pay TV service.

In a filing (PDF) with the FCC, T-Mobile explained how its Layer3 TV acquisition combined with its proposed Sprint acquisition will allow it to offer TV service to a larger number of subscribers.

The company said its 5G network will help the company launched “wireless first” TV in 4K definition for both urban and rural customers. T-Mobile said it will be able to sell the first wireless-only bundle for TV and broadband, and that by owning Sprint will be able to sell to 2x the customer base and more quickly scale the benefits.

The comments within the filing suggest that T-Mobile’s TV service will only be available to T-Mobile and, if the merger is approved, Sprint customers. That would differ from mobile competitor AT&T, which sells its virtual MVPD DirecTV Now and streaming bundle Watch TV to anyone regardless of their wireless provider.

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T-Mobile’s Un-carrier event in August ended up not being about the company’s TV service, but T-Mobile has promised it will launch the service in 2018. Colby Synesael, an analyst at Wall Street research firm Cowen and Company, said T-Mobile’s TV service will be “initially used to reduce churn and longer-term to continue to effectively compete across a growing number of companies we expect to offer a quad play of video, in-home BB, mobile BB and voice.”

Earlier this summer, T-Mobile told the FCC that having both Layer3 and Sprint would allow the company to reduce content costs.

“In the near term, the customer and retail scale created by the transaction will enable New T-Mobile to more rapidly expand the current Layer3 model than possible without the transaction,” said T-Mobile in a filing. “This scale should allow the company to acquire content at lower rates and on better terms than T-Mobile and Layer3 can do on their own.”