TVN TECH

Temporary Antennas Could Aid Repack Work

The FCC can take several more steps to expedite the TV spectrum repack and increase the likelihood of achieving its aggressive timeline, including authorizing the use of temporary side-mount antennas, says Dan Fallon, senior RF engineer at antenna vendor Dielectric.

Completing the repack of TV spectrum within the FCC’s aggressive 39-month timeline will require several significant do-overs by the agency — chief among them an accommodation for temporary TV transmit antennas — but even then meeting the schedule will be dicey.

That’s the bottom line of a presentation by Dan Fallon, senior RF engineer at Dielectric, during a presentation last week at the 2016 NAB Show.

“If everyone tries to build their full replication facility, it can’t be done in three years,” Fallon said during a telephone interview about his “OK, I Have A New Channel. What Now?” NAB presentation.

Putting up a temporary antenna — most likely a side-mount unit with an omnidirectional pattern — as a sort of placeholder to get on air on a newly assigned channel offers a more achievable path forward.

Once the repack dust settles, broadcasters and tower owners can begin the lengthy build-out of beefed-up structures and antennas designed to replicate today’s coverage pattern, he said.

“If the majority of broadcasters approach the problem this way, it is more likely that we are going to meet the tighter time constraint in the three to four years that the wireless guys really want,” he said.

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Adding even greater urgency to the process is the fact that 39 months is a maximum — some stations are likely to be required to vacate their channels far sooner to make way for the new wireless industry spectrum owners.

However, as the rules are written, broadcasters are expected to file for reimbursement from the $1.75 billion TV Broadcaster Relocation Fund for their final covered repack expenses by the end of the three-year relocation process at the latest.

That simply won’t do for the two-step process Fallon envisions because installation of permanent replication facilities could go on for years after a move expedited by side-mount antennas is complete.

As Fallon said during his NAB presentation, “reasonable transition deadlines” are achievable if “everyone realizes full replication facilities may need to be built and paid for after the transition date.”

What makes this approach more reasonable involves many interrelated factors that tip the scale in favor of the one-two punch of first installing a temporary antenna and a permanent antenna later.

For instance, a top-mount permanent antenna replicating an existing antenna pattern can take up to 45 days longer to deliver than a side-mount omnidirectional antenna used on a temporary basis, Fallon said.

Today, 35% of antennas on the 1,663 TV broadcast structures in the United States are top-mount, he said during his presentation. Satisfying channel repack demands from the outset with temporary side-mount antennas could shave 10,000 days or more in the aggregate off the delivery process.

Top-mount antennas also take longer to install, he said. The gin pole alone used by the winch that lifts the new antenna into place can take more than a week to install, Fallon added.

Modifying the reimbursement schedule to accommodate this two-step strategy isn’t the only rule or repack strategy adjustment needed, Fallon said.

Currently, stations must submit an overall estimate of the cost of completing their relocation within three months of receiving a new channel assignment. “I honestly don’t believe, nor do others in the industry, that three months is sufficient time for everybody to do all of that planning,” said Fallon. Six months to a year is a more realistic, he said.

Making precise estimates will require the help of antenna manufacturers, structural engineers and others who are in relatively short supply, especially if their services are needed by everyone all at once.

“Having 800 to 1,000 stations doing all of this [the structural analysis of their towers and consultations on antenna requirements] at the same time makes three months untenable to get a final answer,” he said.

A more workable approach would be to allow stations to treat FCC Form 399, which they must use to submit estimated costs, as a working document that can be updated over time.

“If all the FCC is expecting stations to do is go through the form, check the boxes, and say, ‘OK, I need a new top-mount antenna, and I want a side-mount to get started,’ then three months is fine,” Fallon said.

This approach would, for instance, allow stations to “go through the real planning process with the structural engineers” and submit their budgets for the work as limited industry resources become available, thus sidestepping the logjam Fallon otherwise anticipates.

A hopeful sign of the FCC’s willingness to recognize and begin addressing these types of regulatory hurdles became public on April 18 during the NAB Show. The commission released a declaratory ruling to clarify that it would reimburse TV station owners for relocation expenses incurred before and during the spectrum auction.

Broadcasters should use this opportunity to begin working with structural engineers to determine what sorts of enhancements will be required under newer, more stringent code adopted since their towers were erected, Fallon said.

Steps that can be done right now, he said, include collecting the information antenna manufacturers will need to create an antenna proposal (including the existing coverage pattern to replicate) as well as determining the impact anticipated tower work will have on other tower tenants, such as FM stations on the structure, and hiring a field engineer to do a sweep of existing rigid transmission line.

The line sweep is particularly important because an investment of a few thousand dollars now to characterize what channels an existing line can support could possibly save more than $100,000 for new line to support future operations on a new channel, he said.

Further changes to repack rules to smooth out the kinks in the process — particularly in terms of the timeline the agency has established and the $1.75 billion allocation for the relocation fund — are in the crosshairs of the NAB, said Dennis Wharton, the association’s EVP of communications. The broadcast association is at work lobbying the commission and Congress to modify the repack process to make it successful, he said.

“I think the key to making the whole thing work in a timely manner is managing the 21 or so tower crews available to do the work,” said Fallon.

A critical part of doing so will be further rule changes that allow the most effective use those crews and the limited time allocated for the project.

Read all of TVNewsCheck‘s NAB 2016 news here.

To stay up to date on all things tech, follow Phil Kurz on TVNewsCheck’s Playout tech blog here. And follow him on Twitter: @TVplayout.


Comments (1)

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Ben Gao says:

April 29, 2016 at 2:59 pm

Side-mount tends to induce a tower-shadow zone on VHF in some cases compared to a top-mount antenna. Also, you still need a tower crew, so do you want to pay the tower crew twice (if you can even schedule them) to install a temporary side mount then a permanent top-mount antenna?


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