05.24.2011 11:35 AM
Audio over IP Ready For Prime Time

While Audio over IP (AoIP) is being promoted by some as the future of broadcasting, in truth, it’s already here for many. For audio distribution, network and STL applications, a sampling of involved manufacturers reveals that AoIP offers some significant benefits over TDM and other solutions, including—but by no means limited to—flexibility, scaleability and cost efficiencies.

Just because IP stands for Internet Protocol does not mean that the public internet is involved, however. “There’s a tendency to confuse IP (internet protocol) and internet,” observes Clark Novak, marketing director for Axia Audio, part of the Telos Alliance (which also includes Telos, Omnia and Linear Acoustic). “The public internet is a pretty messy place. Transmitting broadcast-quality programming using the public internet is like sending drinking water down the street using the gutter.”

Axia was launched in 2004 built around the idea that broadcast quality audio could be digitized, packetized and sent over an Ethernet network, says Novak. With the advent of switched Ethernet, he continues, “Instead of the shotgun effect of sending data to every station on the network, we could now send it only to the places that required it and maximize the throughput, the quality of service and the deliverability of that data.”

Now, he says, “Nearly every product among all of our divisions is equipped to send native audio and control over Ethernet connections.”

There are certainly cost savings involved with AoIP, advises Kelly Parker, applications engineer and radio product manager for Wheatstone. “You’re not buying proprietary switching at the core of your system. You can use off-the-shelf equipment from Cisco, HP, Juniper, a number of manufacturers, at lower cost.” A TDM switch from Wheatstone’s Bridge system is $20,000, he reports, versus a $3,000 IP switch.

Plus, “It cuts down on your wiring costs, and your total cost of ownership. That’s another big thing that’s driving people in this direction,” says Parker.

Wheatstone also produces TDM products, says Parker, “But IP is an integral part of what we do. The bulk of our incoming calls, at least on the radio side, are definitely IP-related. So the interest is there now.” Although, he allows, “It’s taken years to get there.”

Glenn Davies with Australian audio codec and STL specialists Tieline Technology, also notes that the hardware required for IP broadcasting is cheaper: “A single IP audio codec can send multiple streams of audio to multiple points, so less hardware is required than over traditional synchronous networks like ISDN and X.21. “Further, an IP network infrastructure is cheaper since it can use existing broadband networks such as DSL/ ADSL, which are generally much cheaper than analog leased lines and synchronous data networks like ISDN (which are being phased out in many regions of the world).

Although Axia encourages clients to keep their audio networks separate from their business systems in order to ensure quality of service (QoS), Novak notes that the system is eminently suited to interacting with third-party equipment. “What good is a network if you can’t plug things into it and make it work? We’ve actively solicited and recruited third-party manufacturers to include Livewire, which is what we call our networking standard, in their products on a native basis,” says Novak. Switch manufacturers tend to support a lot of the IP standards, which allows Wheatstone to tie into third-party devices, says Parker. “For instance, one of the things that we work with is Crestron. They make a lot of controllers for home automation; we have full interfaces to those devices, so you can take your iPhone or iPad and control mixers within our system right from your hand.”

Since IP is just data it can be run through Cat-5e/Cat-6 cables. That provides a lot of flexibility, notes Parker, and allows users to install accessories and control panels for themselves, without having to call on the manufacturer’s support. “You can just sprinkle these controllers and other things around your network and put them in places that you could not put them before.”

Adding a piece of Wheatstone gear is simple, says Parker: “We spent a huge amount of time on the setup wizard that we have built into the devices. We have custom templates in the boxes for audio, so if you want to get one up and running really, really quickly, you select one of our generic templates and it creates the audio and the logic signals for you, and you can start passing audio within a few seconds.”

On the distribution and contribution side, things are just as easy, notes Davies. “There is no longer any need for remote vans and cumbersome microwave links. And a single codec can be preprogrammed to connect to a wired or wireless broadband network very simply.”

Two of Tieline’s newest products will debut at NAB: Genie and Bridge-IT, which are designed to create multiple connections over IP networks. Genie is an STL-grade audio codec for studio-to-transmitter links and audio-distribution applications. Bridge-IT offers a costeffective, high-performance codec solution in point-to-point and multi-point applications.

IP-based systems offer a scalability that cannot be equaled by TDM systems, says Parker. Wheatstone’s WheatNet-IP utilizes a series of Blade units that house the DSP and I/O for the various components on the network. Two new Blades will be introduced at NAB that promise to increase the system’s reach. The company is also launching a new radio console, the IP-12.

IP is far more scaleable than TDM, says Parker. “We could take that up to several thousand by several thousand. But we designed this IP system to take over four billion signals in and out; we have a 32-bit ID. The limit is really only the size of your network.” The flexible and scalable nature of IP hardware offers economies of scale through the consolidation and centralization of a radio network’s audio distribution. Certainly IP allows audio to be sent over significant distances, if necessary. “We have a number of clients who send things not only across campus but across the street or across town. It’s simple to use Ethernet radios, which have a wide enough bandwidth to transmit multiple channels of audio data or to use fiber links or an OC3-dedicated IP channel,” says Novak.

Not that distribution has to be wired. Tieline’s Report-IT Live Enterprise Edition for iPhone has brought a novel newsgathering paradigm to the radio world, turning the iPhone into a portable 15 kHz live IP audio codec and ultra-slim, high-fidelity, 20 kHz audio recorder.

“Wireless IP networks deliver flexible broadcast connections from anywhere at anytime,” observes Davies. Available wireless networks include 3G, BGAN satellite connections and WiMAX, which supports distribution over distances of 2 to 100 km (62 miles).

Novak is pleased that more and more people are at least thinking about AoIP. “They can make their user experiences faster, simpler. They can eliminate redundant I/O and put it all on one little cable, and therefore give a better cost to the end-user for their product.”

More specifically, in the radio studio, says Novak, in the IP network all of the equipment can be controlled from the console, where the operator can focus on the job in hand. “You can eliminate errors in program generation because the operator isn’t casting their gaze all over the studio, just on one area where everything occurs. The show is run more smoothly and more efficiently. It’s a quantum leap, I think.”

-- Steve Harvey, Pro Sound News



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