Tech Focus: Intercoms Move Deeper into Networked Mode

The broadcast sports community looks to finally make the transition to IP

Intercoms have been transporting audio over IP for a decade. Broadcast sports, however, has been playing catch-up in the category.

“We’ve been seeing this on the entertainment side for some time, where they’re more used to trying new things,” observes Vinnie Macri, product marketing manager, Clear-Com.

However, he adds, the sheer scale of intercom for sports productions puts IP bandwidth costs out of reach for all but the biggest, which require dedicated bandwidth from ISPs like Comcast. For the vast majority of broadcasts, such as the hundreds of collegiate games done each year, rented trunked IP would not be cost-effective.

The Internet is an alternative but not for complex productions. “You can’t put Dante or AES67 on the Internet; a Dante stream is 1 Gigabit,” Macri adds. “The benefit of the network is the ability to share [data] over LANs and WANs, especially from venue to venue, such as at the Olympics.”

Bexel’s Rod Allen sees in IP the potential for an intercom tool for budget-challenged sports distributors.

However, the use of Internet connections for moving comms audio on a larger scale appears inevitable, and Clear-Com is looking to its LQ Series interfaces, which can connect two-wire and four-wire audio and call signaling over IP networks as a solution. Macri cites Golf Channel proof-of-concept tests during a tournament at the Doral Golf Resort in Miami last year: eight IP interfaces sent four four-wire comms and IFB audio to the network’s broadcast facility in Orlando. Golf Channel tested a similar configuration of the LQ interfaces at the Masters Tournament in Augusta, GA, last April.

Spectrum Issues
Andy Cocallas, owner of Game Time Communications, sees IP-based intercoms as a solution to disappearing RF spectrum. Game Time has provided intercoms for all 32 NFL stadiums and London’s Wembley Stadium, as well as for numerous Division I, II, and III colleges and high schools.

“Aside from the lower latency and better sound we’re experiencing with audio-over-IP, it’s also more affordable because it eliminates the need for base stations: you can take a direct feed from the beltpack to a network switch,” he explains. “That helps sell it to high schools and smaller colleges and broadcasters, which accelerates its uptake.”

It’s not a perfect solution for large networks. Cocallas cites the need for IT knowledge to keep large networks up and running, as well as the fact that a full-duplex intercom system can cut into network bandwidth. However, each active source on a 100-Mbit VLAN network uses only a fraction of a percent of that bandwidth.

“A system can be used on an existing network and uses only a small part of available bandwidth and does not degrade the host network,” he points out. “It can be as simple or as complex as you want it to be.”

Loss of spectrum is a concern for wireless comms and IFB. Broadcasters and manufacturers alike are phasing out systems that use UHF spectrum, reserving what’s left for wireless microphones. “We’re looking at newer technologies, digital technologies, and higher frequency ranges to address the issue,” says Macri.

According to Rod Allen, senior project manager, Bexel — which sells, rents and manages communications systems for broadcast and other productions — migration to IP-based transport is taking place across the range of intercom types. Two-wire beltpack-based systems have been moved further in that direction by Clear-Com’s HelixNet partyline system, he says, adding that four-wire systems have been using IP-based systems from Clear-Com, Riedel, and Telex for various applications for some time. In particular, he notes how many organizations have been using RTS’s RVON interface to connect VoIP into their ADAM intercom frames.

In terms of wireless communications, Allen points out that the 1.9- and 2.4-GHz ranges are already proving to be viable alternatives to the disappearing UHF bands. He notes that such systems as Clear-Com’s recently upgraded FreeSpeak II wireless intercom system and CoachComm’s Tempest systems, which use an antenna system that can be rolled out over Cat 5 and Cat 6 cabling, can provide comprehensive wireless intercom systems for widely dispersed events.

Looking over the horizon at the potential for WiFi systems, Allen says that products like IntraCom’s V.Com system, which lets personal devices like smartphones plug into a network and act like beltpacks, point toward an intercom tool available to budget-challenged sports distributors, such as small and midsize collegiate and regional sports networks.

Intercoms are one more part of the broadcast-audio ecosphere that’s moving from the circuit to the network. And, even though it’s taking place as the price of copper drops to record levels, the upshot will be faster, simpler, clearer communications.