OPEN MIKE BY SCOTT BARELLA

Sorting Out The SDI-To-IP Migration Standards

The transition from baseband SDI to an open standard internet protocol is underway, aided by the Alliance for IP Media Solutions. But there’s some confusion about AIMS. Who are the standards players and what are their origins? Do they share common goals and objectives, and how do they interact? What is the latest progress on defining interoperability standards for IP-based operations? Here are some answers.

 

It’s hardly news that the broadcast industry is going through a major transition, from baseband serial digital interface (SDI) to internet protocol (IP) as the primary means of moving signals throughout an operation.

No one’s arguing the potential benefits or even the inevitability of the IP migration, but many broadcasters and operators are understandably balking at moving forward. Until the Alliance for IP Media Solutions (AIMS) initiative, an open standard for IP signal transport didn’t exist, and few broadcasters were willing to roll the dice on proprietary technologies for such an expensive and fundamentally disruptive undertaking.

The good news is that various standards efforts are underway thanks to the AIMS, but there’s a fair amount of confusion about their activities. Who are the standards players and what are their origins? Do they share common goals and objectives, and how do they interact? What is the latest progress on defining interoperability standards for IP-based operations?

In this article, we’ll break down the various IP standards initiatives and show how they’re coming together to shape the next generation of uncompressed video.

SDI: The Precedent

For over two decades, SDI — defined by SMPTE 259M for standard definition and SMPTE 292M/274M for high definition — has provided a common language for uncompressed video in media facilities by enabling all pieces of SDI-compliant equipment to share signals, regardless of the manufacturer.

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Another advantage of the SDI format is the ability to embed multiple audio signals with video in a single coax cable. The SDI formats and standards have served the industry so well and for so long because they’ve always been open; from the very beginning, no one ever had to question the interoperability of SDI solutions.

SDI does offer a good role model for adoption of IP standards, but things have gotten a bit more complex after nearly 25 years. For one thing, IP itself is such a broad and flexible concept, encompassing and redefining IT operations in virtually every industry. The technology industry itself is vastly more complex as well, with many more manufacturers offering competing solutions.

The challenge now is how to bring all of these players into step and figure out how to overlay a set of open standards onto an industry that is already becoming defined by proprietary solutions.

The Standards Trinity: VSF, AIMS And SMPTE

The IP standards story begins in 1997, when the Video Services Forum (VSF) was created as an association of service providers, users and manufacturers dedicated to interoperability, quality metrics and education for video networking technologies.

Fast forward to 2014, when the 77 member VSF companies and other industry leaders got together with the idea of recommending standard methods for uncompressed video over IP in a broadcast environment that has traditionally relied on SDI. They formed the Studio Video over IP (SVIP) activity group in April of 2014, and — very impressively — published two technical recommendation documents, TR-03 and TR-04, just over a year later.

It’s important to note that TR-03 and TR-04 are simply recommendations, and if the work stopped there, we might be left with chaos as each manufacturer tried to execute products based on its own interpretation. In other words, interoperability would be lost. Therefore, the two documents needed a push from other bodies to move them into the realm of working proposals and then finalized, adopted standards.

The next step in that continuum was the formation of the Alliance for IP Media Solutions (AIMS), which came together on Dec. 15, 2015, with a mission statement to implement TR-03 and TR-04. The 38 founding member companies of AIMS, of which Utah Scientific is one, are committed to delivering actual, working products based on open video-over-IP standards derived from the road maps established by the two VSF recommendation documents.

With VSF providing the recommendations and AIMS handling implementation and proof of concept, all that remains is to formalize a full-blown SMPTE standard — requiring the involvement of, well, SMPTE. The Society of Motion Picture and Television Engineers is, of course, a household name in our industry, and SMPTE standards have facilitated interoperability in motion imaging for a century — about as long as “motion imaging” has been in existence.

SMPTE has set up the 32NF60 Work Group for SVIP with the goal of codifying SMPTE Standard 2110, a true specification embodied by VSF TR-03 and TR-04. This draft group began work in earnest shortly before the 2016 NAB Show in April, and among its members are the VSF cohorts that authored the original recommendation documents along with members from AIMS as well.

Other Players

Along the way, other organizations are contributing important pieces to the IP standards puzzle. The Advanced Media Workgroup Alliance (AMWA), a group closely associated with AIMS, took the initiative to tackle a very fundamental requirement for IP solutions — the discovery and registration of IP addresses.

Not wishing to re-invent the wheel, AIMS has just adopted AMWA’s NMOS protocol, which will possibly be incorporated into SMPTE 2110. In another example, the Audio Engineering Society has gone to great lengths to create AES 67, a standard for uncompressed audio over IP that has been recently adopted by VSF and is also in TR-03 and TR-04. AMWA has been holding interoperability tests throughout the year.

The Joint Task force for Networked Media, JT-NM is also an organization that combines the VSF, SMPTE and the European Broadcast Union (EBU) and supports a number of interoperability events for companies to test and measure their works freely using these new standards.

One more effort worth mentioning is Adaptive Sample Picture Encapsulation (ASPEN), an IP system created and solely owned by Evertz. Late last year, Evertz submitted ASPEN to SMPTE as a Registered Disclosure Document. Think of this as an open standard developed without collaboration since it’s owned by a single company, of greatest value to operations that have standardized on Evertz equipment. Just before the NAB Show, Evertz and its close partner Sony joined the AIMS group. This eliminated any controversy in competing IP standards: AIMS or ASPEN.

What Happens Now?

With the industry coalescing around SMPTE 2110, momentum is building toward an open standard for IP signal transport. At this writing, the 32NF60 Work Group is making progress on SMPTE 2110, with possible completion by mid-2017.

A big milestone happened in August, when JT-NM staged one of the first SMPTE 2022-6 with TR-03 interoperability tests — giving more than 32 member manufacturers a chance to see how well their respective solutions work together in an IP setting.

The interop was successful and the results were later showcased at IBC so attendees could see the tangible audio and uncompressed video signals being sent and received via IP using COTS Ethernet fabric.

While the draft 2110 standard is still in progress, many vendors gained valuable insight to the usage of IP and the benefits it will soon bring to the broadcast industry.

There are no winners with chaos, but SMPTE 2110 will be a win-win for everyone — especially broadcast customers. Rather than having to take a big gulp and then proceed down an uncertain path to IP operations, media companies will be able to move forward with the confidence that an open, standards-based environment brings.

In the short term, this will take the form of interoperable, AIMS-compliant solutions that are battle-hardened by the August testing. In the longer term, we see a day when SMPTE 2110 will take its place alongside SDI as an uncompressed video format whose openness is a foregone conclusion.

As chief technology officer of Utah Scientific, Scott Barella is also deputy chair of AIMS and a member of VSF and SMPTE, where he plays an active role in development of IP broadcast standards.

Further reading: “An Argument for Open IP Standards in the Media Industry,” Alliance for IP Media Solutions, March 2016 


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