With Shane Tove

Digital Networks Must Facilitate Operations

But the modern digital network can do much more by Anke Schneider

The author is sales, marketing and PR manager for 2wcom Systems GmbH.

These days most studios run their AoIP networks to produce audio content. In theory, keeping the studio’s contribution separate from distribution offers flexibility at all sites; and separating the audio portion from transmitting sources such as satellite, DAB+ or IP provides various benefits.

Practically speaking, it’s now necessary to change perspective: IP offers broadcasters significantly more flexibility for the transmission of content, so more and more broadcasters A typical facility distribution following the audio, left to right, from a studio and recording studios are deciding to expand through 2wcom digital audio IP encoders into the 2wcom multimedia over IP IP-based networks. network cloud (MoIN). It then moves into available distribution channels — internet, DAB multiplex or satellite — and then onto broadcast transmitters.

But broadband and fiber optic are growing at very different rates internationally. So in addition to the use of IP-based structures, flexible alterMoreover, compatibility of the different frame sizes of native distribution paths must be available. AAC Profiles and Opus is important. Put each manufac

This leads to the question of how best to link contributurer through its paces to ensure that its products suption and distribution. The answer is to keep it in segments, port all possible variants of an audio algorithm. because an increasing number of stations are multimedia, Third, the codec must support all common protocols streaming audio and video along their facility’s networks. as well as standards for internet interoperability such as Livewire+, Ravenna, AES67, EBU Tech 3326 or SMPTE FIRST SEGMENT: STUDIO SITES ST2110 full-stack. To connect the studio’s networks with the headend and Fourth, flexible stream management must be possible finally all transmitter sites, we should consider several in means of channel scalability and MPEG multiplexing aspects for our audio setup. The AoIP codec chosen for facilities. This includes perfect network synchronization this should meet at least five key requirements. by supporting PTPv2 and 1PPS. Especially for audio

First, it must be stable even when operating in WANs. description of live events, synchronization down to the This can be achieved by providing features for transmismicrosecond is essential. sion robustness like redundant internal or external power Fifth, management and control of each audio over supplies; software redundancy, e.g. forward error correcIP codec of all studios in a network should be available tion or SRT; and dual streaming or parallel streaming with remotely via PC web interface, supporting SNMP, Ember+, different audio bitrates. Also, please consider a backup JSON or NMOS. The main system control should be acceswith an alternative source to ensure that your content is sible hands-on via local hardware control in case a WAN transmitted, say, via satellite in case IP lines fail. becomes inaccessible.

Second, the codec must provide all audio formats norAs a result of the above, all studios in a static or mobile mally used in a studio, like Enhanced aptX, most ACC pronetwork can fall back on a unified codec solution while files or MPEG formats, Opus, Ogg Vorbis, PCM and Dolby. keeping their independence. From a budgetary point of

view, a system as described above provides the chance for all studios of a network to rely on existing AoIP setups.

SECOND SEGMENT: HEADEND

The demand for the perfect link at the headend implies all of the requirements mentioned above, plus NTP (Network Time Protocol) for network synchronization. Moreover, the solution should just collect the forwarded studio programs to make them available by simply transcoding the streams respectively to the different distribution sources — audio over IP, DAB+ or satellite. This could be achieved by a multimedia-over-IP network server software, flexible, integratable into existing structures in hardware, VMs or as a containerized cloud service.

A system setup that fulfills the requirements described above ensures a “non-locked-in” arrangement. The headend/multiplexing system and studio systems are not hosted on the same network but kept separate from each other; thus, it is possible to replace one or the other if needed without bringing the companion operation down.

An aside about virtualization. We are at the beginning of the use of virtualized products. Be aware that virtualization counts on maintenance. This goes along with the wishes I have often heard from our customers that a broadcast network should be expandable as easily as possible, add new services with a mouse click and mirror the configuration of one device to another.

Scalability can be notably improved by using virtualization strategies. The possibilities that have been introduced by Docker or VMware to copy instances, take snapshots or run them across multiple hardware devices are a great improvement to scale and maintain networks.

That also has a major impact on needed rack space. Thanks to virtualization, applications can share the same hardware or even run as a swarm across multiple hardware units with different hardware configurations.

As a result, the number of devices needed is reduced to a minimum, because server hardware has in most cases a lot more processing power than the specialized hardware of codec manufacturers. Thanks to AES67 and

Audio is directly fed into the 2wcom MoIN digital multimedia network, where it can be routed to a streaming encoder or directly to a content delivery network and then into web streaming. The author says solutions that support standards, protocols, multiple audio formats and redundancy enable the most use cases.

other AoIP standards, the requirements for real hardware interfaces are slowly disappearing, and that is opening the door for virtualized solutions dependent on an all-IP infrastructure. With high bandwidth and robust IP lines, audio processing in the cloud becomes possible. In consequence, manufacturers have to pick up the pace and offer their solutions as virtualized software.

THIRD SEGMENT — IMAGINATION

With a little imagination such networks have been utilized for a variety of transportation duties. Here’s a beginning list.

Icecast/HLS to DVB Transport Stream Transcoding: This is used by a number of customers who want to make webstreams available on a DVB transport stream that can be sent in cable networks or via satellite.

Streaming Encoder: Software can also be used to feed a streaming encoder, for example, the Wowza streaming cloud; or the solution transcodes the audio signals to adaptive bitrate protocols like HLS that can be distributed to the end customer by using a CDN.

AES67 to WAN Bridge: With a great number of supported audio over IP protocols, a “multimedia over IP” network server can transcode signals from studio networks that use AES67, Dante, WheatNet, Ravenna or Livewire+ to a format that is suitable for wide-area networks. For example, the studio signals can be transcoded to Opus for a low-bitrate transmission with SMPTE 2022 conform error protection or using Secure Reliable Transport (SRT). That enables a studio-to-studio bridge that can overcome even stressful network conditions.

On-Demand Transcoders: The multimedia over IP network server software offers scalable activation of codecs in means of number and time. This allows flexible handling of alternative audio streams such as an audio description of a video, to guarantee accessibility for blind and visually handicapped persons. Or, when a multimedia contribution is produced, operators are enabled to process simultaneous audio commentaries for the video, station website, social media and the radio broadcast.

Use Case: Four Programs to 14 Locations

ANTOFAGASTA 106.3 COPIADO 97.7

Integrator puts Barix and Wheatstone gear to work

by Alfonso O. Lopez

OVALLE 96.7

Signal 1 Signal 2 Signal 3 Signal 4

PNCGUIPULLI 92.3 OSORNO 89.1 VALDIVIA 105.7

WHEAT-IP AES/EBU

WHEAT-IP AES/EBU WHEAT-IP AES/EBU WHEAT-IP AES/EBU

NORTH ZONE

DOWNTOWN AREA CONNECTION VIA PUBLIC INTERNET

CONNECTION VIA PUBLIC INTERNET

WHEATSTONE SWITCHBLADE

OPEN INTERNET DEDICATED 5MB CONNECTION, TRANSMISSION VIA SIP

PUBLIC

CONNECTION VIA PUBLIC INTERNET

CONNECTION VIA PUBLIC INTERNET SOUTH ZONE

SOUTH ZONE

SAN FELIPE 92.7 SAN ANTONIO 89.1 CONSTITUCION 92.9

Chillan 88.7

Summary:

Distribution of four audio sources streaming WheatNet-IP audio to 14 locations using Wheatstone SwitchBlade, decoding signal via SIP protocol / OPUS codec with Barix M400 Opus Decoders.

Hardware required:

4 Channel WheatNet-IP license for audio servers 1 Wheatstone SwitchBlade 14 Barix M400

Minimum internet requirements:

Head-end 5 MB Each remote site 512 K

CASTRO 97.9 PUERTO AYSEN 94.1 COYHAIQUE 89.5 PUNTA ARENAS 90.7

The application uses 14 Barix M400 units and Wheatstone WheatNet-IP and SwitchBlade to serve 14 transmission sites via the internet.

The author is president of 305 Broadcast.

For 26 years I have been working as an integrator specializing in Latin America. My career started at a small company called Digital Link, then I became the owner of 305 Broadcast in Miami, where we distribute more than 150 brands in our industry, among them Barix.

In today’s chaotic situation with COVID-19, codecs have become an essential tool to every broadcaster both for remote and distribution unicast/multicast. We as integrators have found that many infrastructures were already prepared to receive and send audio via IP, but not to the extent needed in these circumstances.

A project that caught our attention to share for this ebook was in Chile. This customer needed to distribute four different programs to 14 locations. We suggested using a new Wheatstone SwitchBlade distribution 16-channel system together with the new Barix Opus Decoder. The combination of these units allowed the customer to have control of each stream individually from the main headquarters.

The diagram above tells the whole story. This configuration is not only cost-effective but also allows a level of independent control on each stream and studio.