Facebook asked the FCC for permission to test a "converged wireless system" that could potentially support simultaneous communications across Wi-Fi and cellular networks. However, the company's application raises more questions than it answers.

In its filing, Facebook said it is researching a "proof of concept for a converged wireless system that will operate at the 2.4GHz Wi-Fi band and at Band 3."

Continued the company: "The goal of the proof of concept is to create a demonstration and see if such a system may be viable. The system that will be tested will have a simple radio head that will be able to operate as a Wi-Fi Radio at 2.4GHz and as a Band 3 cellular radio concurrently. We will wirelessly connect dedicated client devices to demonstrate performance."

The company's application – filed under the "FCL Tech" name that Facebook has used in the past for other wireless tests – mentions equipment supplied by electronics component supplier AVX. The company plans to conduct the tests at its Menlo Park, California, headquarters.

According to Brian Goemmer, founder of spectrum-tracking company AllNet Insights, Facebook's mention of Band 3 is noteworthy because that band is only used in Europe. He said Band 3's downlink runs in 1805-1880MHz and is roughly comparable to the PCS band in the US, which is Band 2 and runs across 1930-1990MHz in the downlink.

"I'm not sure why they don't test a PCS-Wi-Fi device," he wrote in response to questions from Light Reading.

To be clear, Facebook routinely tests new wireless technologies. That's because the company's Facebook Connectivity operation for years has been working to expand Internet coverage globally – and therefore the reach of the company's social network – through various wireless technologies ranging from Magma to Terregraph. Further, Facebook's Telecom Infra Project serves as one of several organizations where wireless network operators, vendors and others work together on new wireless technologies and network designs.

But what Facebook might intend to do with AVX equipment in Band 3 and 2.4GHz is unclear. Companies typically do not discuss their wireless networking research and development plans.

Importantly, there is precedent for cellular communications in the unlicensed bands typically used for Wi-Fi. After all, the US wireless industry pushed hard for regulatory approval for License Assisted Access (LAA) technology, which allows wireless network operators to expand their 4G communications into the unlicensed 5GHz band in order to improve their network capacity. Operators ranging from T-Mobile to Verizon have employed LAA technology in order to offer faster speeds to customers.

Further, there's new technology in the 3GPP's new 5G specifications designed to allow operators to deploy a 5G network in unlicensed spectrum, like they would a Wi-Fi network.

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— Mike Dano, Editorial Director, 5G & Mobile Strategies, Light Reading | @mikeddano