AT&T and Verizon are trying to convince the Federal Communications Commission that mobile broadband is good enough for Internet users who don't have access to fiber or cable services.

The carriers made this claim despite the data usage and speed limitations of mobile services. In the mobile market, even "unlimited" plans can be throttled to unusable speeds after a customer uses just 25GB or so a month. Mobile carriers impose even stricter limits on phone hotspots, making it difficult to use mobile services across multiple devices in the home.

The carriers ignored those limits in filings they submitted for the FCC's annual review of broadband deployment.

FCC’s annual broadband review

If the FCC decides that broadband is being deployed to all Americans in a reasonable and timely fashion, the agency isn't required to do as much to accelerate deployment or promote competition. Treating mobile and fixed broadband as substitutes for each other would effectively lower the bar in the FCC's analysis of whether the current state of broadband deployment is good enough. Even areas that lack fiber or cable service are likely to have mobile access.

In January 2018, the FCC concluded that broadband deployment is happening quickly enough for the first time since the Bush administration. But Chairman Ajit Pai stopped short of declaring mobile access a full substitute for fixed broadband services such as fiber and cable.

AT&T and Verizon want that to change when the FCC releases the next version of the report, likely early next year. Pai's FCC previously "refused to acknowledge mobile broadband as a substitute for fixed," AT&T complained in an FCC filing this week.

AT&T continued, citing data from an industry-funded group:

Even today, a recent study by the Internet Innovation Alliance (IIA) demonstrates that significant numbers of consumers are using mobile devices for activities that were once dominated by personal computers and larger-screen televisions. For example, the study shows that a clear majority of consumers use mobile devices for "bandwidth and data-intensive applications" like streaming multimedia content—including watching news and sports, as well as streaming movies and television shows from services like Netflix, Hulu, etc. Notably, these results are consistent across different racial groups, different residential areas, and different income levels. The study also demonstrates that mobile broadband has a prominent role in American education, reporting that "nearly half of all US households with school age children have relied on mobile devices to complete homework assignments in the past year." With 5G services offering speeds of up to 1 Gig and beyond, consumers will undoubtedly view wireless services as an even more compelling alternative to fixed.

Verizon told the FCC that its annual analysis should be "broad enough to account for broadband deployment overall... including how consumers may use mobile broadband to supplement or substitute for fixed broadband."

"[A]ny analysis of broadband availability based on the number of providers... should reflect the number of fixed and mobile broadband providers (i.e., the number of providers offering some form of broadband, regardless of technology)," Verizon also said.

Verizon noted that Comcast and Charter are offering mobile broadband as resellers of Verizon service and that various messaging and VoIP apps compete against the major carriers' voice and text services.

NCTA, the cable lobby that represents Comcast, Charter, and other ISPs, made a similar argument:

In the 2018 Report, the Commission found that mobile service is not a complete substitute for fixed service, but it acknowledged that both fixed and mobile broadband services "clearly provide[] capabilities that satisfy the statutory definition of advanced telecommunications capability." We note that services need not have identical characteristics to be considered substitutes, but at a minimum the Commission should take into account that millions of consumers choose to rely solely on mobile broadband services even where they have the option to purchase fixed services, and that this number appears poised to increase as 5G wireless services are deployed.

Pai’s FCC changed course after criticism

Pai's FCC last year drew criticism by initially suggesting that mobile Internet might be all that Americans need. By contrast, the Obama-era FCC concluded that Americans need home and mobile access because the two types of services have different capabilities and limitations.

Pai's FCC faced a backlash from Internet users who pointed out that mobile connections are hindered by data caps, limits on tethering, and reliability problems that make it fall short of a wired Internet connection. Pai's FCC eventually acknowledged that mobile broadband is not a full substitute for home Internet services.

The FCC kicked off its current broadband analysis last month with a Notice of Inquiry that proposes to maintain the commission's fixed broadband standard at the current level of 25Mbps downstream and 3Mbps upstream.

The FCC notice also sought comment "on whether and to what extent fixed and mobile services of similar functionality are substitutes for each other." While the 2018 report found that mobile is not a full substitute for fixed home broadband, "we seek comment on whether since the 2018 Report there have been developments that would support a different conclusion about substitutability," the FCC's notice said.

Advocates say mobile serves different needs

Consumer advocacy groups urged the FCC to reject the notion that mobile broadband is a full substitute for home Internet services.

"[T]he technological characteristics combined with consumer expectations make fixed and mobile services distinct, complementary products," Common Cause and Public Knowledge wrote in an FCC filing. "For example, mobile broadband services typically come with data caps where the mobile network operator places a limit on the amount of data a customer can use over their Internet connection. Once a customer reaches that limit, the mobile carrier engages in certain actions such as slowing down data speeds or charging fees for data overages. This makes it difficult for consumers to continuously use data-intensive applications like video streaming or file downloads on a mobile connection, compared to a fixed connection where large amounts of data usage are generally permitted and speeds are typically not throttled for heavy usage."

Fixed and mobile also differ when it comes to "pricing models, variability of speed, and reliability," and thus serve different needs, the groups said.

New America's Open Technology Institute similarly wrote that mobile broadband plans "include data caps, limited bandwidth capacity, and unique pricing models that are foreign to the market of fixed [broadband] providers because the two services meet different consumer needs."

The Open Technology Institute also urged the FCC to raise its fixed broadband speed standard and to require greater competition levels before declaring that broadband is being deployed in a reasonable and timely manner.

The FCC's 2018 report measured deployment by summing the populations of census blocks with at least one provider, the Open Technology Institute said. Instead, the FCC should put a greater emphasis on how many Americans have a choice of high-speed providers, the group said.

"A one-provider threshold wrongly suggests that one provider is an adequate baseline for reasonable and timely broadband deployment," the Institute said. "Competition is an important indicator of network investment and quality. The Commission's previous methodology obscured this fact by only measuring the number of Americans with at least one [broadband] provider."

Disclosure: The Advance/Newhouse Partnership, which owns 13 percent of Charter, is part of Advance Publications. Advance Publications owns Condé Nast, which owns Ars Technica.