Tech Focus: Networked Audio, Part 1: For AoIP, the Future Has Arrived
Consoles are remotely commissioned; comms span continents; production is seamless from truck to studio
In retrospect, audio over IP networks was inevitable. The migration from a dedicated cable/channel-signal environment to a network-based model over the past 10 years was on the same track that the shift from analog to digital was on three decades earlier. But a few things happened to accelerate the trend.“It was a nitro explosion,” says Tim Casey, support technician, Calrec Audio, choosing a not-inapt metaphor to describe how the conventional field production model for broadcast was suddenly rendered moot by the COVID pandemic. “If [a broadcaster] wanted to televise a sporting event, it couldn’t send hundreds of people to a location and had to find other ways to do all that. I think the networks were building up to a future where they could remotely control cameras and microphones and switch and route
remotely, but it was going to be probably 10 years away. Then, when COVID came along, it was like, let’s make this work now! Everybody had to make it work by necessity.”
From Toll Road to Open Road
However, a fundamental shift like this has a lot of moving parts, and, serendipitously, many of those parts were already in motion. Two in particular were critical: the widespread adoption of Dante, Audinate’s proprietary network protocol that took advantage of the innately slow-turning gears of standards-based technology codification with aggressive marketing, and the rolling arrival of AES67 and the SMPTE ST 2110 group of networking standards.
The path to networked signal transport had already developed a number of proprietary or hybrid toll roads, so to speak: Lawo participated in the development of RAVENNA; Calrec had its Hydra network; Wheatstone had WheatNet; QSC was seeing success with its Q-SYS system deployed in broadcast and sports facilities on the installed-AV side. What could have been a multi-fronted Edison-vs.-Tesla–scale tussle (with enough drama to perhaps warrant its own cinematic version) was instead channeled by a combination of Dante’s rapid success in gaining adherents (licensees, in its case); the pandemic’s acceleration of the need for centralized remote operations; and the arrival of a suite of standards that encouraged cooperation — in the form of enhanced interoperability and intercompatibility — into a kind of model for a United Nations of technology.
“ST 2110 codified how all the vendors are supposed to interact with each other. Before, it was kind of like one of those standoffs where whose chicken and whose egg is going to come along first?” says Casey. “Once the 2110 standards were codified, the manufacturers and vendors could adhere to them and then do their plugfests” — gatherings where manufacturers’ engineering representatives, overseen by recently established organizations such as the Alliance for IP Media Solutions (AIMS) and the AVnu Alliance, could iron out discrepancies between applications that might meet on an IP network in the field.
(AIMS hosted its first live interoperability demonstration of Internet Protocol Media Experience (IPMX), a set of standards-based protocols designed to ensure interoperability for AV over IP, at InfoComm 2022 in Las Vegas last week.)
In the slow and uneven retreat of the COVID pandemic, the broadcast business is formalizing the use of remote operations, via REMI or at-home workflows. Calrec’s Casey cites the ability to commission new audio consoles remotely, instead of having to send engineers onsite.
“As many of the newer products are already IP-based,” he says, “it became easier than ever to go that route. For very large broadcast [operations], it might still make sense to have people onsite, but smaller operations, such as regional sports networks, will be prime candidates for remote commissioning.”
For intercoms, which have migrated rapidly to networked environments in recent years, the future has already arrived. For instance, during the 2022 Beijing Olympics broadcasts last winter, RTS’s ODIN and ADAM matrix frames were deployed to create a seamless global communications network.
“I would type in an alpha on my RTS keypanel in Connecticut, and it would pop up like it always does,” said Jeremy Katz, who worked as the audio guarantee on the production, first on location from Beijing and then from NBC Sports’ Stamford, CT, facility. “Even though we were literally a world apart, operationally, it felt like we were just on a normal remote, working in an OB truck together. The director would say something, and the camera guy in Beijing would react in real time, just like on any other broadcast.”
Microphones have moved into networks. Both Audio-Technica’s ATND971A cardioid condenser boundary microphone and Sennheiser’s TeamConnect Ceiling 2 microphone have Dante network outputs.
Interestingly, both were originally developed for the corporate/conference-room market but may eventually migrate to broadcast sports, as Shure’s MXA710 steerable linear array did. The array’s steerable transducers, guided through Shure’s proprietary IntelliMix DSP and Autofocus technology, are compatible with both Dante and AES67 audio-networking protocols and were used by TNT Audio Supervisor Dave Grundtvig for coverage of this year’s NBA All-Star Game.
“Using this, we can create steerable lobes and point them in different directions as needed, remotely,” says Grundtvig, who has also experimented with network-controlled microphones for baseball and NBA Summer League. “This is a whole new category of microphone for broadcast applications. We’re in uncharted territory with this.”
In the House
At the facility level, CP Communications and its subsidiary Red House Streaming have converted their St. Petersburg, FL, headquarters into a specialized broadcast and production center that can seamlessly manage live content coming from and going to any location globally, without leaving the IP domain. The operation comprises a varied network infrastructure of 1-Gb and 10-Gb pipes interface with its two RHS studios and extends to its new RHS-36 truck. The facility has already hosted several REMI productions, including the Bermuda Track and Field Championships and two ACC Golf Championship events.
“Regardless of which production service is used, we acquire in IP, produce in IP, and distribute in IP,” said Kurt Heitmann, CEO, CP Communications and Red House Streaming, in a prepared statement. “We can keep it all in IP with our vMix workflows or also decode content for a traditional SDI workflow onboard RHS-36. We can then encode it back to IP for distribution [using IP compression standards in ways that allow clients to capture, edit, process, and deliver programming in their preferred formats]. We work in compressed environments, instead of moving uncompressed content around the facility on network cable. Working in compressed environments gives our clients the freedom to manage content to and from anywhere globally over IP in a variety of formats, including RTMP, RTSP, SRT, and NDI.”
AoIP was never not going to happen, but the swiftness with which it has arrived and been integrated into broadcast-audio workflows, combined with broadcasting’s need for ever greater efficiencies, suggests that the trend will only get more deeply embedded.
Click here for Tech Focus: Networked Audio, Part 2: Standards Bring Order to a Profusion of Formats.