American Tower could look outside its traditional pool of wireless operators to boost business as more players express interest in the 3.5 GHz CBRS band and millimeter wave spectrum for next generation use cases.

That was the takeaway from an exchange between BTIG’s Walter Piecyk and American Tower CEO Jim Taiclet during last week’s second quarter earnings call. In response to a question from Piecyk about whether non-wireless operators have expressed interest in the company’s tower portfolio, Taiclet conceded those conversations are indeed “happening.”

“So we’ve been after this segment for a long time, the nontraditional segment,” Taiclet commented. “It’s a substantial amount of our domestic U.S. business, upwards of 15 percent, 20 percent, and it includes broadcast customers and others that will augment our sort of traditional mobile network operator customer base.”

In particular, Taiclet pointed to American Tower’s involvement in the CBRS Alliance as a potential “catalyst to bring other types of tenants into the business for us.” Members of the Alliance include traditional wireless carriers like AT&T, Sprint, T-Mobile, and Verizon, but also other companies like Comcast, Ligado Networks, Rivada Networks, Boingo Wireless, Telrad, Mobilitie, and SpiderCloud Wireless, among others. Though not part of the group, Google and Apple have also filed with the FCC to conduct tests on 3.5 GHz and 28 GHz, respectively.

Taiclet added that American Tower is also quietly working to develop a number of vertical markets as well. Those, he said, include WiFi (with customers like Gogo), finance, and government.

But any potential gains for American Tower could be in jeopardy if the sharing format of the 3.5 GHz band is changed.

Wireless incumbents like T-Mobile and industry group CTIA are lobbying the FCC to revise its existing rules for the CBRS band to include longer license terms and license areas that cover Partial Economic Areas rather than census tracts. T-Mobile also asked that the Commission open all 150 MHz of the 3.5 GHz band to priority access licensing rather than allowing just 70 MHz per market under the current rules.

The requests have sparked backlash from public advocacy and wireless internet service provider groups, which have called the proposals “ill-conceived,” “destructive,” and “self-serving.”

More on that debate here, here, and here.