In making a case for merging with Sprint, T-Mobile said in May that it hoped to leverage the smaller carrier’s network to offer “fixed 5G” service — home broadband internet — in a challenge to cable companies. Now the carrier is telling the FCC (via FierceWireless) that it’s planning to challenge top cable internet providers Charter and Comcast on pricing, service levels, and scale.

According to T-Mobile’s FCC filing, the company’s fixed 5G push will begin in earnest, initially winning 1.9 million customers by 2021, then 9.5 million by 2024 — enough to make it the country’s fourth-largest home ISP. By 2024, the company expects to be offering home internet service in 52 percent of U.S. zip codes — which equates to 64 percent of Charter’s territory and 68 percent of Comcast’s — while also using network optimization technologies to serve more households per area than the cable companies.

One interesting data point is T-Mobile’s planned home broadband service level: a nationwide average download speed of 100Mbps. While that’s 3 times faster than standard residential broadband today, it’s only one-third the speed Verizon is calling typical for the 5G home broadband service it will launch next month and one-tenth Verizon’s promised peak of 1Gbps.

T-Mobile expects to increase its speeds by 2024, offering 300Mbps downloads to over 250 million potential customers and over 500Mbps downloads to another 200 million people, depending on region. It remains to be seen whether that will be enough to compete with Verizon, to say nothing of the cable companies, which are now looking at 10Gbps wired solutions as a way to retain customers.

Aggressive pricing and greater convenience may help T-Mobile win over broadband users. Company COO Mike Sievert suggests research “has confirmed that there is a large market for New T-Mobile’s in-home broadband offering at the anticipated pricing and service levels” and said that the company’s wireless hardware will let customers self-provision in-home equipment, rather than waiting on and paying for in-home installation.

Sievert also expects that some of T-Mobile’s smartphone customers — 5.8 million households by 2021, 6.3 million by 2024 — will be using their mobile service for all of their broadband needs, rather than subscribing separately to “home” and “mobile” service. That could work for some customers — particularly less bandwidth-demanding individuals and couples, rather than larger families with higher collective service needs.

If the Sprint merger is approved, T-Mobile has said it will build the core of its nationwide 5G network using Sprint’s 2.5GHz spectrum holdings, augmented with both lower- and higher-frequency spectrums. Though the 2.5GHz band has certain advantages, including range and ease of implementation for equipment makers, it may be saddled with lower speeds and higher latency, depending on how T-Mobile and its competitors execute on their 5G strategies.