It’s no secret that Verizon is gearing up for pre-commercial fixed wireless 5G trials using 28 GHz spectrum, but it seems the carrier is seeking to supplement those trials with a new series of tests.

In an application filed at the end last week, Verizon asked the FCC for permission to conduct tests in the 28 GHz band in Euless, Texas and South Plainfield, N.J. over the next six months. Verizon said the tests would utilize equipment from five different vendors, including Ericsson, Intel, Qualcomm, Samsung, and Nokia.

Verizon said the Texas location is a Verizon Mobile Switching Center with apartments nearby, while the New Jersey site is a “developed urban area with adjacent buildings and trees.”

According to Verizon, the purpose of the tests is to “understand the characteristics of mmWave operating bands, specifically 28 GHz, including channel bandwidths, and U/L ratios for residential/commercial deployments.” And it looks like Verizon is planning to play with 256-QAM again in addition to 16- and 64-QAM in the proposed trial at the Texas location.

Last year, Verizon applied to conduct nearly an identical set of tests, 256-QAM included, though Nokia was not among those on the vendor list. That application came shortly after Verizon announced its deal to acquire XO Communications and lease 28 GHz spectrum from the company's affiliate with an option to buy down the line.

It’s interesting, but not surprising that Verizon is looking at 256-QAM in the tests. The technology is one of the many stepping stones to 5G, and helps increase download speeds by boosting the number of bits delivered per transmission.

A Verizon spokeswoman on Monday confirmed the technology is already live in "some parts" of the carrier's network. And fellow carriers T-Mobile and Sprint have previously touted their work with 256-QAM.

In September, T-Mobile announced the launch of 256-QAM and 4x4 MIMO on its network. Un-carrier CTO Nevill Ray said the combination of those technologies offers download speeds of up to 400 Mbps. And last month at CES, Ray said 256-QAM was one of the tools T-Mobile will use to hit gigabit speeds.

Back in December, Sprint executives also said 256-QAM was a step on the ladder to hitting 1 Gbps. During the launch of its High Performance User Equipment (HPUE) technology, Sprint CTO Jon Saw said 256-QAM will be used in conjunction with carrier aggregation, 4x4 MIMO, and HPUE to hit the gigabit milestone on its licensed spectrum.

AT&T, however, has been mum on the subject and could not immediately be reached for a comment Monday.