The Technical Trends Committee

FCC Update

At the beginning of June 2018, T-Mobile announced that they are ahead of schedule in the testing of their Extended LTE operations in the 600 MHz band, and they expect to have active testing of the C, D, and E bands on line by the last quarter of 2018, in almost a thousand counties across the USA. This will render the bands between 627 MHz and 642 MHz, and between 673 MHz and 688 MHz unusable and against the law to operate in. This equates to approximately the upper half of Lectro Block 24, and most of Lectro Block 26.

A list of areas expected to be up and running in these bands, listed by state and county, is available via the T-Mobile web pages at: https://howmobileworks.com/spectrum/

The 600 MHz band is no longer referenced by UHF TV stations 38 through 51 (614 MHz to 698 MHz). 614 MHz to 617 MHz is the GUARD BAND between UHF 36, reserved for radio astronomy, and the DOWNLINK bands, 5 MHz each, A through G (617 MHz to 652 MHz). An 11 MHz band, the DUPLEX GAP, is between 652 MHz and 663 MHz, followed by the UPLINK bands A through G (663 MHz to 698 MHz).

What does this mean for wireless microphone use?

First, a reminder that any transmitter working at 698 MHz or above has been unlawful to use for over a decade. Do not go there…

In 2020, it will be unlawful to operate transmitters in the 600 MHz band, with a few exceptions—limited use of the GUARD BAND and limited use of the DUPLEX GAP. Note that areas in the old VHF band have been made available for wireless mic use, along with a few slices of the 900 MHz band (941 MHz and 944 MHz). An in-depth review of these new areas will be the subject of an upcoming tech trends column. It is important to note that a good chunk of the DUPLEX GAP will be reserved for licensed users.

Till then, transmitters operating between 614 MHz and 698 MHz are allowed unless T-Mobile is testing operations on those frequencies. Scan the bands intended to be used before turning transmitters on; if the cell system is operating in one or more of the cell bands, it will be obvious in the scan. If a cell band is active, it may not be used for wireless mic operation.

If you hold a Part 74 license, continue to operate, but be aware that operation in 600 MHz could go away overnight. If you do not hold a license, don’t get caught operating where you shouldn’t. No one has been fined for unlawful operation yet, but the penalties can be significant—$11,000/transmitter/day with a cap at $82,000, and up to six months in jail.

Currently, the Local 695 web pages for applying for a Part 74 license are down. We are in the process of vetting new applications under the new “post incentive auction” rules; when we are sure the process is working, the web pages will go back online.  

In other news from the Local 695 Technical Trends Committee, plans are underway for an up-to-date reboot of the Local’s Survival Guide pages, where one can brush up on the operation of unfamiliar recorders, mixers, and control surfaces.

Also, the Technical Trends Committee is participating in the growing cross-departmental “Voluntary Stewardship of the
2.4 GHz and 5 GHz Bands” program that aims to establish protocols for interdepartmental coordination of the Wi-Fi bands in the production environment, and to make the AMPTP and producers aware of the need for coordination in these bands during pre-production.

Questions or comments – [email protected]