Study Hall

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State Of The Union: The RF & Wireless System Picture Heading Into 2018

Time is no longer on our side as change is coming rapidly in the 600 MHz spectrum.

One year ago, the U.S. pro audio industry was anxiously awaiting the impending outcome of the 600 MHz auction. We didn’t know much except that RF products operating in the 600 MHz band would likely be phased out over the next three years.

When the auction was completed in April 2017, the big winner was T-Mobile, which spent just under $8 billion for its share of radio spectrum across the country and immediately announced plans to start testing by year’s end.

As many in our business now know, T-Mobile is making good on that promise, currently commencing services in more than 300 counties across the U.S. Once any auction winner begins testing in the 600 MHz spectrum, it becomes illegal to operate wireless microphone, in-ear monitoring, and intercom systems in that cellular block. The fine for doing so is more than $10,000 per day (per frequency!).

In discussions with T-Mobile’s internal 600 MHz group, we’ve learned the company is planning to commence services in most major markets, including the metropolitan areas, beginning in the second quarter of 2018. Only one or two of their licensed pair of 5 MHz blocks will be used, with the remaining block pair(s) going live in 2019 after the Institute of Electrical and Electronics Engineers (IEEE) finalizes the 5G Standard.

And because T-Mobile – and any other auction winner for that matter – may test in any block of frequencies above 600 MHz in any open TV channel in the U.S. at any point in time, wireless system users all must assume that open channels above 600 MHz are not usable (unless you know for a fact that an auction winner is not testing).

To simplify what this means: I’ve done my last show using equipment that operates above 608 MHz, except for the 653-663 MHz duplex gap. If there are no DTV stations in the duplex gap, then we can be assured that those frequencies will remain clean for wireless system usage, as long as the special restrictions for that band are met, until we get a better sense for the RF out of band emissions by the adjacent LTE downlink and uplink.

In addition to auction winners energizing and testing, the great television repack will begin in earnest in 2018. The Federal Communications Commission (FCC) has a 10-phase plan to move all the UHF TV stations above 600 MHz to below the auctioned spectrum. Most of these TV stations will move to a lower band UHF TV channel.

Out of nearly 2,000 UHF TV stations above 600 MHz, only 13 will be moving to the high VHF band (174-216). However, it’s also important to note that in its quest for a fast rollout, T-Mobile, with cash in hand, is actively working with TV stations to move earlier than their phase assignment where possible.

This means that those of us that utilize wireless systems and other RF equipment now have the knowledge to make good purchasing and budgeting decisions for new equipment that will be necessary by the end of 2018.

For my events, I’m reserving what little is left of the traditional UHF spectrum for wireless microphones and IEMs. This is primarily due to current manufactured equipment availability, although several companies are making headway in this area.

One entity of note is Audio-Technica-owned Alteros, which has introduced a wireless microphone system that operates at 6.5 GHz. I’ve tested it many times in the harshest environments and intend to make use of this band now that professional level equipment is available, in addition to keeping an eye on other product developments as well.

As far as communications and IFB equipment is concerned, I’ll operate all in alternate radio spectrum such as VHF or above 1 GHz. These radio bands, most of which are new to the wireless operator, require a bit of a learning curve. Radio waves behave differently in both VHF and high-band UHF, and for some bands, there are some additional regulatory matters to consider.

Do your homework when making a purchasing decision. Know that time is no longer on our side. We need to make alternative plans for all equipment operating in 600 MHz by the end of 2018.



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