Immersive Audio: Optimizing Infrastructure

Though a mainstay of the broadcast realm – namely, live sports – all but disappeared with the worldwide spread of the coronavirus, the industry has actually been making great strides in bringing viewers engaging content. Forced by circumstance to be more creative and innovative, broadcasters are testing and implementing new technologies they hope will keep them competitive until and beyond the return of sports live broadcasting.

Immersive audio is among the technologies gaining traction in broadcast. Thanks to the shift to IP, it is becoming easier for broadcasters to handle the signals necessary to offer viewers an immersive experience — be it the feeling of sitting at the center of the action or the ability to choose from additional audio elements such as mic’d up players, communications between driver and pit crew, etc.

IP makes broadcasters’ embrace immersive audio easier, but that doesn’t mean it’s simple. Like traditional sound fields, immersive audio uses left, center, right, left surround, right surround, and subwoofer/low-frequency effects — and then it adds a height layer and top layer. On top of that comes metadata that describes how audio should be reproduced within the sound field. To create “audio objects” that can be placed or moved around the listener, this metadata defines the position, spread, and motion characteristics for sound.

All of these new audio flows and associated metadata add up. While this may be manageable in early stages of adoption, the larger volume of sources, signals, and data will make scaling up a challenge as broadcasters increase their use of immersive audio.

Broadcasters can do several things to mitigate this challenge. Integrated with switching infrastructure, automation, control, and orchestration will be critical to managing the overall workflow and enable appropriate QoS treatment. Implementation of more comprehensive PTP network practices will help to ensure the integrity of timing/synchronization from end to end. Use of PTP-aware managed switches support this effort by exposing APIs for control and provisioning.

In fact, AoIP, managed, and PTP-enabled switches are a great solution for immersive audio workflows, as they supply robust traffic control/management and PTP functionality. With a switching infrastructure that can manage traffic adeptly, broadcasters can bring order to the signal flows and data associated with immersive audio.

A common approach is to bundle audio sources and objects according to preset categories, which might include the location of the source, the type of sound, or specific effect captured. The switching infrastructure can use VLANs to group flows and data while managing traffic and bandwidth — particularly when other types of traffic are present, as well.

Given the demands of live events, it also can be useful to deploy networks to accommodate the relationship of different switches to specific sources. And, using the boundary clock function of the switch, it’s possible to sectionalize the PTP network and attain even better performance.

Immersive audio offers broadcasters a valuable option for engaging audiences — new and old — as sports and other live events return. Thanks to audio over IP and advanced infrastructure (including Artel’s Quarra family of switches!), broadcasters have the tools and functionality they need to make more immersive live programming a success.

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