Broadcast TV Audio Riding The IP Wave

Manufacturers of audio equipment for TV broadcasters are seeing steady adoption of IP networking technology that is enabling more flexible, cost-effective production workflows.

The audio-over-IP systems are also helping to pave the way for next-generation audio with the new ATSC 3.0 TV standard, including such features as immersive sound and object-based audio.

At the same time, wireless microphone vendors and their customers are tackling the present-day challenge of moving off of the 600 MHz UHF spectrum, which has long been used for news and sports production but has now been reassigned by FCC auction to wireless companies.

All will be hot audio topics at the NAB 2018 show in Las Vegas this April.

“The trend toward IP is definitely big and gaining momentum in the broadcast space,” says Joshua Rush, VP of marketing for Audinate, the New South Wales, Australia-based company that makes the popular Dante networking technology.

Audinate has seen a major increase in the adoption of audio-over-IP by the television industry in the past two years. It now licenses Dante to more than 350 companies that have built the audio networking technology into over 1,300 products.

“People’s comfort level in doing things over IP networks has really begun to settle in,” adds Gordon Kapes, president of Studio Technologies, which makes a variety of Dante audio-over-IP interfaces for intercoms, IFBs (interruptible fold-back) and consoles.

While different audio-over-IP protocols like Dante, Ravenna and WheatNet-IP have been used for years, the inclusion of the AES67 audio transport standard in the newly-published SMPTE ST 2110 suite of standards for handling media over IP networks helps ensure interoperability across a wide range of different vendors’ products. That becomes more important in remote production schemes where, for example, audio from a Dante-driven facility might be transported to a broadcaster that uses Ravenna.

The next step to fully exploiting audio-over-IP technology will be a standardized specification for sending control data over the IP network, says Dave Letson, VP of sales for audio console supplier Calrec, which counts NBC and Fox as major customers.

He notes that Calrec works with both the Ravenna and Dante protocols and has already been making AES67-compliant products for several years.

“Now that [AES67] is starting to be used and adopted by customers, the question has moved away from transporting audio and video over IP cable to controlling that,” says Letson. He thinks the NMOS (Networked Media Open Specifications) IS-04 for Discovery and Registration specification, developed by the Advanced Media Workflow Association (AMWA), is a likely candidate.

Rush says that functions beyond baseline transport, like discovery and registration — which allows a device to be plugged into a network and have its name automatically pop up — as well as monitoring and security are already built into Dante. But he says that Audinate will keep up with any new standards and likely “fold it into Dante.”

Sports production has been a major driver of audio-over-IP. Mobile truck vendors benefit from the weight and space savings of moving their audio networking from multiple analog cables to a single Ethernet cable. And the myriad audio feeds at a sports venue, from field mics to network commentators to half-time entertainment, are easier to manage with IP.

“IP makes those things a lot easier to interconnect,” Rush says.

Calrec customers are taking advantage of audio-over-IP transport to do more “remote” or “at-home” sports productions where on-site gear is minimal and live audio and video feeds are transported over telco lines to be produced in a distant studio, instead of being produced onsite in an expensive mobile truck.

“There are a couple of people really pushing the envelope,” says Letson. “I think this year people will really start to move forward from experiments to real-world applications.”

The main driver is cost savings, as broadcasters try to cheaply produce an ever-increasing number of local, college and niche sports programming. Transport technology from vendors like Net Insight has improved to the point “where people are no longer afraid of the telephone network,” says Letson.

And audio vendors are figuring out how to cope with the inherent latency problems of long-distance transport. For example, Calrec’s RP1 remote production unit provides local in-ear mixing for sports commentators, latency-free, that can be controlled by a console in a distant studio.

Intercom and IFB systems for everyday news production at the station level have also been steadily migrating to IP. Vendors like Telos Systems, Riedel and Clear-Com have sold wired IP intercom solutions running over Ethernet cable for years, and they are now bringing that capability into the wireless realm in different ways.

Riedel, for example, offers Bolero, a six-channel wireless intercom system that runs over an AES67 IP network and works with Riedel’s Artist digital matrix intercom platform.

Bolero is based on the Digital Enhanced Cordless Communications (DECT) standard and operates in the 1.9 GHz frequency band, and can be used as wireless beltpack, wireless keypanel or as a walkie-talkie radio.

Clear-Com sells several DECT-based digital wireless intercoms that operate in the 1.9 GHz and/or 2.4 GHz bands, and the company adds IP functionality through its Agent-IC Mobile App for iOS and Android devices. Agent-IC, which was introduced a couple years ago and is now used by several hundred stations, enables IFB, party-line and point-to-point communications over any internet connection including Wi-Fi, 3G, 4G and LTE.

The app is a free download, with the software license included with each frame (module) of intercom hardware. Some stations have over 40 Agent-IC apps deployed, while 10 to 12 in heavy use is typical, says John Kowalski, director of broadcast and network sales for Clear-Com. Some stations have even relied on the app during disasters such as hurricanes to maintain on-air communications, as it allows a station in duress to connect to a hub or sister station and maintain IFB and party-line communications.

“A news director can connect to the intercom and make rundown changes right there on their phone,” says Kowalski. “The mobile app for intercom has been one of the strongest products we’ve offered.”

While wireless intercom systems began moving out of the 600 MHz UHF TV spectrum to other frequencies years ago, notes Kowalski, the majority of wireless microphones still operate there today. But that will be changing soon, with 84 MHz of the 600 MHz band being sold in last year’s FCC incentive auction to companies including T-Mobile, Dish, Comcast and AT&T.

Once those companies begin operations (even testing) in their newly acquired spectrum, wireless mic and IFB users who previously used those frequencies can’t interfere. While the official deadline for the transition is July 13, 2020, new 600 MHz licensees can start using the spectrum earlier and unprotected users — which include low-power TV stations and translators as well as wireless mics — have to clear out.

T-Mobile, which dominated the auction by spending $8 billion on spectrum, took some broadcasters by surprise by beginning testing last year in several markets. For example, 16 low-power stations in Arizona were notified by T-Mobile last summer that they had until Nov. 1, 2017, to clear out.

While T-Mobile eventually postponed operations until Dec. 1, and worked to accommodate the LPTVs, it was still a surprise to local users, says Karl Voss, chief engineer of KAET Phoenix and frequency coordinator for both the Society of Broadcast Engineers and the National Football League (Voss is in charge of frequency coordination for Sunday’s Super Bowl).

“Northern Arizona University had a whole boatload of 600 MHz mics, and they were absolutely clueless they had to move,” says Voss.

To address the 600 MHz issue, wireless microphone and IFB manufacturers like Lectrosonics, Sennheiser and Shure have developed gear that works on different frequencies, such as lower or higher UHF, VHF and unlicensed frequencies like the 1.9 GHz and 2.4 GHz bands. They are also offering trade-in and/or rebate programs to their customers to help speed the transition.

Karl Winkler, VP of sales for Lectrosonics, says that the total number of affected mics may number in the “hundreds of thousands” when considering the whole universe of wireless mic users.

“People are making the tough choice to potentially return them, or scrap them,” Winkler says. “There are a lot of different options.”

The replacement cost is not insignificant. Wireless mics run $1,500 to $3,000 per channel and an IFB channel is about $1,500, says Winkler, with a traditional live ENG truck typically using six mics and three or four IFB channels. Under Lectrosonics’ trade-in program, stations handing over their old gear can get up to 12% off the cost of a new mic.

The company is also offer a “reblocking” program for late-model mics, where the mic can be sent to Letrosonics and the circuit board can simply be replaced with one that operates on new frequencies, then shipped back. That process can cost from one-third to one-half the cost of a new mic.

“We’ve started getting flooded with those,” Winkler says.

Another solution to the 600 MHz situation is being offered by Alteros, an Audio-Technica spinoff that has developed an ultra-wideband digital wireless microphone system, the GTX Series, that operates on the unlicensed 6.5 GHz band.

The Alteros GTX system provides 24 audio channels and doesn’t require frequency coordination. An early adopter was ESPN, which used it successfully for its U.S. Open tennis coverage last summer.

The Alteros system isn’t cheap — it costs $5,000 per channel, roughly twice the cost of the wireless mics typically used for ENG. But Alteros President-CTO Jackie Green says investing in the GTX Series not only means getting superior performance, but also represents a smart hedge against further spectrum issues. While Green concedes there is “no totally safe spectrum,” she says the GTX Series operates in a relatively uncrowded swath of spectrum, as globally the spectrum that is being targeted by telcos is either below 6 GHz or above 10 GHz.

“If you’re going to invest money in a new system, why would you invest in something that might be obsolete in two to three years?” says Green.

Something that also might be obsolete in two to three years is a TV viewer’s notion of what constitutes great sound, given the next-generation audio capabilities of the new ATSC 3.0 standard.

At the Broadcast Engineering and Information Technology Conference at NAB on Tuesday, April 10, an entire day will be devoted to the possibilities of immersive audio, which includes Dolby Atmos 5.1.4, with four overhead channels that are fed to ceiling speakers; and object-based audio, which uses metadata to deliver personalized audio streams to a TV set or set-top box, such as a “home announcer” commentary feed for a sports broadcast.

ATSC veteran Jim Starzynski, director and principal audio engineer for NBCUniversal, will be moderating next-gen audio presentations from companies including Junger Audio, Avid, Fraunhofer and Genelec.

Vendors will also be exhibiting 3.0-compliant audio gear on the show floor, such as the Linear Acoustic AMS Authoring and Monitoring System from audio conglomerate The Telos Alliance.

The Linear Acoustic AMS system creates and monitors MPEG-H audio and metadata for ATSC 3.0 streams, as well as simultaneous 5.1 audio for ATSC 1.0 broadcasts, and is being used by NBC for its 4K coverage of the 2018 Winter Olympics in Korea this month.

Producing next-generation audio will take a little getting used to, says Larry Schindel, Telos Alliance TVSG/Linear Acoustic’s senior product manager. While today broadcasters send a complete audio mix, generally a 5.1 surround mix in English and a separate stereo mix for secondary audio programming (SAP) in Spanish, with next-gen audio a broadcaster would instead send out separate audio elements with descriptive metadata that would then be assembled in the consumer’s receiver.

Dolby Atmos 5.1.4 broadcasts are already offered by some pay-TV services, such as BT Sport in the United Kingdom, and Schindel thinks object-based audio may also be introduced in the next few years. That would mean personalized audio for viewers, such as a choice of commentators for a sports broadcast or a visually impaired descriptive service with true 5.1 surround sound instead of the mono audio offered today.

“I think you’ll start seeing it in the next year or two, and I really think sporting events will drive this,” Schindel says. “The nice thing about the way next-gen audio is set up is that you don’t have to retransmit it and take up valuable bandwidth in the audio stream.”

Read all of TVNewsCheck‘s NAB 2018 news here.