Posts Categorised: spectrum

Making the important decisions and executing the plan

This article is the second in a series about mitigating the impact of the spectrum repack, as told by iHeartMedia Los Angeles Vice President of Engineering Doug Irwin. Read the first installment here. 


Not long after this news about the Deer Park construction go-ahead came out, our SVP of Engineering Tom Cox let me know the basic framework of the project — what we wanted to achieve, and how much the budget was. It was up to me to meet the goals within the budget framework.

This room seemed tailor-made for our needs. Note the already-in-place ATS. Outside was its associated generator set. We did decide to replace the old air conditioner.

One question that needed to be addressed was just how long we had to put all of this together. I did reach out to local TV engineers, as I mentioned earlier, but none really had finalized plans. The best I could get was “We’ll be doing that over the summertime.” 

So — since summer officially starts on June 21 — I decided that the end of May was a reasonable goal for the new site to be ready. Somewhat random, I will admit, but there was very little else to go on.

Early in the project we worked on deciding if we wanted to use two antennas fed from two separate 2-channel star combiners; or alternatively, a single antenna with a 4-channel combiner. Eventually we decided to go with the single antenna. The reasons are quite, simple really.

CBS TV used to maintain some satellite uplinks up at CBS lane, and they had a special room built in “the house” to accommodate the control gear. Sometime earlier all of it had been abandoned in place. In typical CBS fashion, it was all put together very nicely, and seemed nearly custom made for our needs. 

It already had an ATS and generator outside, as well. The contacts in the ATS are limited to 150A though; and considering the ERP and antenna gain we would have to work with (for the single 8-bay antenna) the amount of current needed by the transmitters was going to fit comfortably within that limit. 

If I had opted for lower antenna gain, I would have needed more transmitter power, which would have necessitated an upgrade to the electrical system. For this reason we decided to go with the 8-bay antenna.

The old channel 2 batwing, and KCBS-FM’s tertiary antenna.


Once we had the antenna picked (an 8-bay, half-wave spaced ERI Axiom) we went back to ATC and let them do the mechanical study. Unfortunately, the results were not good: The tower as-it stood was not strong enough to hold up our chosen antenna.

However, ATC has all the resources at hand to study the issue and to come up with the fixes needed. In addition, since we had picked ERI already, the two engineering teams worked together to come up with the pole needed to hold up this rather large antenna, and the more specifically, the modifications needed to the tower to make it work for the application. The pole, the tower modifications, and installation of both were on ATC’s dime. 

The only real question was whether or not that part would get done on time.


Dielectric, ERI, and Shively were all solicited for bids for the antenna and combiner. Naturally, I had to consider pricing, but with the upcoming re-pack work, I also had to consider how long the various companies would take to deliver the antenna and/or combiner. In the end I ended up choosing Shively for the combiner, and (as I already wrote) ERI for the antenna. Both had good combinations of pricing and delivery time.

The transmitter choice was pretty easy for me, since we already had two Nautel GV-series transmitters in place and on-air (for KOST and KYSR). 

Clearly, Nautel isn’t the only brand that can do what it does; however, it’s easier from an on-going maintenance perspective to have the same transmitters across our stations —from spares to software updates to staff knowledge. 

Working backwards (from the antenna down) and knowing the ERP we were looking for on each station, I chose two GV10s, a GV5, and a VS2.5 with the VS-HD. Yes—we were adding HD to all the stations as well. The footprints of these transmitters would also be easily accommodated with the space in the old CBS satellite room, along with three racks.


Our stations on Mt Wilson each have three STLs to choose from (not including our VSAT system) and it was my intention to have all three of them also available at Deer Park.

Additionally, we have transmitter-site versions of our automation system — the idea being that they are ready to play-out audio in the event we have a system meltdown in Burbank— and I wanted that audio to be available at Deer Park as well. The reality is that I wanted to “copy” whatever I was doing up on Video Rd, and to “paste” it down at Deer Park.

At last year’s Radio Show, I was introduced to the newest member of GatesAir’s IP link family — the IP MPXp. By simply sampling the composite outputs of our current set of audio processors — with their custom settings are particular on-air qualities — we could literally do the “copy and paste” method I was after. 

By using the MPXp, we would have access to our main and backup audio processors, each of which is driven by the output of a 4X1 AES selector, thus:

  • Giving us access to all three STLs down at Deer Park
  • And making sure the Deer Park transmitters sound identical to the Video Rd. transmitters
  • By adding RDS to the appropriate inputs on the audio processors, we have access to it as well at Deer Park

So as you can see, there was no need to buy additional audio processors or RDS generators. The MPXp units are configured to use a 132 KHz sample rate, thus giving them an audio bandwidth of 60 KHz — more than enough to include all the stereo information and RDS.


Since Deer Park is .6 miles west of the main sites at Video Rd., we clearly needed some way of making them communicate. I opted for a licensed radio solution; however, the time to implement such a system ended up being more than we had to work with. For that reason, we opted to install a parallel 5.8 GHz radio link between the buildings as well.

Three of our four stations are in the Post Office building on Video Rd.; however, KBIG is next door in the Poole building. We had no fast communications between the buildings (though they are on the same AT&T switched Ethernet circuit — thus providing 10 mbps of connectivity between the two). 

Since we had the IP MPXp to pass information from the Poole building to Deer Park, it was clear we needed to connect the Poole building to the Post Office before anything else. We ended up doing that with yet another unlicensed radio — this time at 60 GHz. It was an experiment that worked out well enough for us to keep it going. To be fair, this radio includes yet another 5.8 GHz radio, embedded, so that it can keep passing data even if the 60 GHz portion fades or fails.

Next time: we start putting it all together.

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After the Incentive Auction

Doug Irwin explains what really happened to some radio stations affected by the spectrum repack

The author is vice president of engineering for iHeartMedia’s Los Angeles region and a regular contributor to Radio. This is the first in a series about how Doug and his colleagues are handling the repack.

Not long after the incentive auction came to a close last year it started to become obvious that we — iHeartMedia Los Angeles cluster — would be adversely affected by changes occurring in our immediate area on Video Rd (on Mt Wilson). 

We have three stations in the Post Office building, making use of three towers that surround the building. These include:

  • The KIIS-FM main, auxiliary and an aux used by our HD Radio transmitter
  • The KRRL main and its aux (also used for HD)
  • The KOST main antenna and its aux antenna

Additionally, immediately next door, to the west at the Poole building (now owned and operated by Insite), we have KBIG’s main and aux, and our auxiliary site for KYSR.

In the immediate neighborhood to our four stations on Mt Wilson are various FM stations, including Entercom’s 97.1 (Amp) and KRTH at 101.1. Cumulus’ KLOS (95.5) is also close by.

The TV stations directly affected by the incentive auction results are:

  • KDOC, which is moving down the road to Deer Park, to the new DTV site on the tall tower
  • KOCE, which is going off-air
  • KJLA, which is going off-air
  • KXLA, which is staying
  • KCBS-TV, which is moving from RF channel 43 to channel 31, and thus changing antennas
  • KTLA, which is going from RF channel 31 to channel 35, and likely changing antennas (full plan not known at this time, at least by me)

As time went by late last year, we asked the TV engineers for more details on their plans, but for the most part, they were not forthcoming. The reality is that not all of the plans were in place, so they couldn’t tell us what they were. We knew something was going to happen, we just didn’t know exactly what or when.


The group of stations that I’ve discussed has been very cooperative, among the ad-hoc group, with power reductions when the need arises. Many times one of the stations needed scheduled maintenance, which was usually preceded by an announcement one or two weeks in advance. Everyone prepared for it ahead of time. Occasionally, some sort of failure would necessitate an immediate repair, again accommodated well by the group, with everyone in the neighborhood going down in power by 50%. (Radio stations insisted that power reductions not occur prior to 10 a.m., and if at all possible, end by 3 p.m.)

Our corporate engineering asked about the possibility of power reductions, or worse, in the near future, to satisfy the needs of TV stations making substantial changes. I responded that the 50% power reduction had, up to that point, been good enough, and “likely” would continue to be. After all, everyone had an ox to be gored — so everyone was incentivized not to change the way we’ve been doing things. But clearly, I couldn’t guarantee the same process would always work.

Eventually, in the fall of last year (and especially after the infamous article about the repack that specifically mentioned KIIS-FM and KOST) the corporation decided that we needed to take a far more proactive approach and to build an entirely different site, in order to minimize the impact of the upcoming work. 

I was tasked with finding the site.


Every year (almost without fail) the Southern California Frequency Coordinating Committee puts on the Christmas party at Mt Wilson, during July. Yes, a bit early, but it’s a real tradition. 

Naturally, the weather is great (as opposed to Christmas time), and in 2017, representatives from American Tower Corp were on site to update the Mt Wilson crowd on what was coming up with respect to the repack. 

At the same time, a couple of their guys were going to show us two sites, either of which they thought would work for our repack site: Mt Harvard, and Deer Park. Having not been to either, I very much looked forward to the opportunity.


This site is about two miles southeast of Mt Wilson at about 5,000 feet of elevation, so it covers the greater Los Angeles and Orange county area similarly. It’s not a popular site for FM, though. The major tenant is KUSC radio.

In my “discovery trip” email, I wrote the following: “This tower and antenna [shown at right] belong to KUSC radio, even though KUSC’s transmitter is up in the ATC building. It’s a curious arrangement. The building directly below this tower (which we believe belongs to ION media) has the space I mentioned above. As you can see, there’s an old transmission line running up the tower; some station removed a TV antenna evidently.” It’s a great looking tower, and there is physical space directly below that of KUSC; however, being that low to the ground could present a problem with NIER levels.

Another tower at Mt Harvard looked good but had little-to-no available space (left):

At that time I wrote: “This is the tower currently with the ION antenna. Below that you can see a 4-bay dielectric, the KLOS aux. Below that, a channel 6 basket; and below that, the old FLO antenna, which could be removed. Unfortunately this space isn’t that large or high AGL. The tower is triangular, and the most favorable leg is the one that the FLO antenna is on. So, for us, the best aperture is unfortunately adjacent to the ION antenna.” The tower looks great but there’s no space on it.

There’s also a very large candelabra-type tower on Mt Harvard (right):

I wrote: “This picture shows the structure for all the various TV antennas. Some of these are going, but it’s pretty clear that using any available space on this tower would subject us to repack work at this site.”

So, while Mt Harvard had some potential, the reality is that antenna space was at a premium (at the time) and, just like our situation on Video Rd., the TV stations didn’t have their plans in place.


The ATC guys were very interested in showing us what ATC had available at Deer Park, which is a site they bought out from CBS TV.

Formerly known as “123 CBS Lane,” Deer Park at that time was really only hosting its main tenant: KCBS-FM. It’s about .6 miles west of the main grouping of antennas on Mt Wilson; there’s an 800-ft tower there, along with a shorter one, which at one point was used by KCBS-TV for their aux antenna on channel 2, and was still in place.

At the time, I wrote: “The short tower [right] is ASR 1229046…It’s 245 feet to the very top. The last section of the tower is a pylon which is currently holding an old channel 2 batwing, obviously abandoned. What we’re thinking is that the batwing would come down, and we’d re-use the space for at least one of our antennas. Now, notice the 2-bay Jampro; that belongs to KCBS-FM.

“There’s a virtually empty building near the base of this tower — so space is abundant. The building doesn’t look great but evidently isn’t suffering too much for leaks. The roof actually looks new. There’s a generator available as well, but it appears to be only a 50 KVA set.

“If I had to pick between Deer Park and Mt Harvard, I would definitely pick Deer Park. Coverage considerations aside (since I can’t study them), I would say it would be easier, cheaper and faster to make use of this (relatively) small tower. I would also gauge that the ATC guys would prefer this solution as well, for what that’s worth.”

Next time: How I designed our new site.

Go to Radio Magazine Online

Commission alleges 65 AV transmitters intended to relay video to UAS can transmit in unauthorized radio frequency bands

WASHINGTON — The Federal Communications Commission is proposing to come down hard on a manufacturer whose devices could potentially transmit without authorization in certain radio frequency bands.

The FCC proposed a $2.8 million penalty against HobbyKing, a provider of audio/video transmitters that are intended to relay video to unmanned aircraft systems and other devices. According to the commission, 65 of these devices have the alleged capacity to transmit in unauthorized radio frequency bands, including some models that could allegedly operate at what the FCC called “excessive transmission power levels.”

According to the commission, transmissions such as these could potentially interfere with key government and public safety services like aviation systems and weather radar systems.

The FCC did not detail any specific incidents in its announcement.

Through its website , the Hong Kong-based company markets devices that the commission said provides a video link between transmitters that are mounted on unmanned aircraft systems and users who are flying drones. According to the commission, HobbyKing represented that its transmitters operated in designated amateur radio bands; an investigation by the FCC’s Enforcement Bureau found that 65 models could also apparently operate outside those bands.

FCC authority is required for users operating a radio frequency-emitting device that could potentially operate outside of the designated amateur-use radio frequency bands. The commission said that none of the devices in question marketed by HobbyKing were certified by the commission. In addition, the FCC said that all amateur equipment used to telecommand model crafts are limited to 1,000 mW of power. The commission said in its announcement that three HobbyKing transmitter models allegedly operate at 1,500 mW and 2000 mW.

Following complaints to the FCC, the bureau opened an investigation in 2015 into the company’s marketing of radio frequency devices and issued a formal citation in 2017 to warn the company that it must comply with FCC requirements.

The steep proposed penalty is not only for marketing noncompliant radio frequency devices but also for failing to comply with commission orders. According to the commission, HobbyKing failed to respond to the enforcement bureau’s previously issued a citation notifying HobbyKing of its legal and regulatory obligations. The company also failed to stop marketing the alleged noncompliant equipment despite a cease and desist order from the FCC. Current law requires companies to respond to requests from the FCC after being warned of possible violations.

The FCC said that HobbyKing has an opportunity to respond to the proposed assessment, and reminded the public that the commission will consider submitted evidence and legal arguments before taking further action.

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In a letter CTIA President calls for making July into “mid-band spectrum month”

WASHINGTON — Wireless carriers want the FCC to add a vote on opening up the 3.5 GHz band at its July meeting, and an auction of that spectrum by next year.

That is according to a letter from CTIA President Meredith Attwell Baker.

“The wireless industry urges the Commission to move forward in July on key mid-band spectrum opportunities—the 3.5 GHz band and the 3.7-4.2 GHz band—to address the United States’ international deficit with respect to mid-band spectrum availability,” She wrote to the FCC.

The commission is already planning to vote on opening up the 3.7-4.2 GHz mid-band spectrum at the meeting, which CTIA is all for. But Attwell Baker wants to turn July into “mid-band spectrum month” by moving on the 3.5 GHZ band as well as the rest of the world races toward 5G.

To help light a fire under the proceeding, Attwell Baker pointed out that the U.S. is ranked sixth in mid-band spectrum availability, while South Korea plans to auction 3.5 GHZ spectrum next month.

Specifically, Attwell Baker wants the FCC to finalize its 3.5 GHZ band rules by July, and announce a 2019 auction of 70 MHz of licensed spectrum.

CTIA cited the compromise it had reached with the Competitive Carriers Association on license sizes as paving the way for the FCC to wrap up optimization of the licensing regime to make sure the licenses are investment and innovation friendly.

CTIA and the Competitive Carriers Association have agreed that the FCC should issue MSA (Metropolitan Statistical Area) licenses in the top 306 cellular markets, but smaller, county-based licenses for the remaining 428.

It argues that using census tracts as the license sizes would lead to unprecedented complexity.

The FCC voted last October on a proposed framework for freeing up the 3.5 GHz spectrum — it would be shared with incumbent government users — for wireless broadband that could encourage cable and telco broadband players to use, and bid on, that spectrum in the race to 5G.

Changes to the priority access license in the band are meant to incentivize faster network broadband deployments of fixed and mobile service. Those include longer license terms and contemplating different sized licenses.

NCTA-The Internet & Television Association has been pushing for smaller sized licenses —its compromise between partial economic areas and census tracks is county-sized licenses . Cable ops are eyeing that swath of spectrum for their own wireless and mobile services.

But it does not want them too small either. NCTA member Charter has advocated for license areas bigger than census tracts but no bigger than counties.

NCTA has told the FCC it is also ready and willing to find compromise to avoid delay.

Go to Radio Magazine Online

The company is asking for Special Temporary Authority to advance its understanding of 5G and network potential in the millimeter wave bands

STAMFORD, Conn. — Charter Communications is going ahead with more tests of fixed wireless in the 28 GHz band, in and around the Los Angeles area. The cable company is asking the FCC for Special Temporary Authority to advance its understanding of 5G technology and network potential in the millimeter wave bands, according to . The application lists Ericsson as the manufacturer of 25 units to be tested.

The company is asking for the STA for 180 days, starting at the end of March. The goal of the tests is to develop techniques and to gain a greater understanding of fixed wireless broadband systems in the millimeter-wave bands.

Charter is also seeking permission to conduct more tests to study coverage, capacity and propagation in the 3550-3700 MHz CBRS band. Their latest application calls for outdoor fixed wireless experiments in Lexington, Kentucky, using 19 different models of equipment, according to the same article. “Charter plans to continue testing in rural communities to investigate further how to expand the speeds and services it delivers,” the company said.

Charter has also shown its support to the FCC for the opening of the 5.9 GHz band for unlicensed use as soon as possible, noting the 5.9 GHz band’s size, location and capacity would be ideal for “next-gen” technologies.

Go to Radio Magazine Online

Pai Welcomes NTIA Spectrum Study

Will explore 3450-3550 MHz band’s suitability for commercial wireless services

WASHINGTON — “We are fully committed to collaborating with NTIA to ensure that the U.S. continues to lead the world in advanced wireless technologies as we chart the course to our 5G future,” FCC Chairman Ajit Pai said in a statement Monday.

Pai was reacting to the announcement that the U.S. Department of Commerce’s National Telecommunications and Information Administration’s has selected the 3450-3550 MHz band for a feasibility study exploring the band’s potential for commercial wireless services; this spectrum is currently used for federal purposes, according to Pai’s statement.

[Read more: “NTIA Offers Expanded Federal Government Spectrum Use Reports ”]

“The commission, working together with NTIA, has already made the 3.5 GHz band available for wireless services and we recently initiated a process to consider whether all or parts of the adjacent satellite spectrum can also be made available. Altogether, this could unleash a contiguous block of hundreds of megahertz of valuable spectrum for new technologies and services, including 5G,” Pai said.

Go to Radio Magazine Online

Lawyer Peter Tannewald says the commission has proposed to regular, unlicensed and experimental licensing

WASHINGTON — The Federal Communications Commission has signaled its intent to look into issuing licenses for frequencies above 95 GHz with recent vote to issue a Notice of Proposed Rulemaking and Order.

“That’s GigaHertz, not MegaHertz — way up there, beyond the highest frequencies that are commonly used today, at least by the private sector,” Peter Tannenwald points out in his latest CommLawBlog entry .

Tannewald says the commission “has proposed to authorize three types of operations: regular licensing, unlicensed systems and experimental licensing.” Also, the FCC proposes “to permit the sale of new equipment during market trials.”

He adds that this is a shift in part driven by ham radio operators, who have long been allowed to operate above 95 GHz.

This is likely good news for those concerned about the spectrum crunch, since the “amount of available bandwidth is enormous; so if the high frequencies can be used, the possibilities for ever-faster wireless broadband and backhaul speeds are significant.”

These moves are also in the context of a vote to propose rules to implement the requirement that the FCC “act on petitions or applications for new technologies and services within one year of receipt.” The commission suggests the Office of Engineering and Technology recommend within 90 days whether “a new technology should be put on a one-year track or processed normally.”

Read the full article at CommLawBlog.

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