Joint-Task Force on Networked Media (JT-NM) assumed of path of networked media development as of April 2017. It will evolve over time.
SMPTE ST 2110 is currently in final draft and possibly will soon be published. Different from previous SMPTE standards, SMPTE 2110 is a Family of Standards covering live production based on IP. However, because it is still under wraps in the secret world of committee, there is scant information on where things stand This article will provide some important background.
In this article I will explain of what a Family of Standards is and provide an explanation of who are the immediate family members of ST-2110.
First, let’s review the protocols, technical references and other standards involved in the formation of the ST-2110 family. It’s an impressive list. Consider this a list of characters and relationships, much like an author might describe at the beginning of a novel to help set the stage for the story that follows.
- SMPTE 2022-1/2 – MPEGTS - the first encapsulated IP video stream standard, MPEG2
- SMPTE 302 – Audio over MPEGTS 2022 1/2
- SMPTE ST 2038 – Ancillary data over 2022 1/2
- SMPTE ST 291 – Ancillary data using RTP (Real Time Protocol)
- SMPTE – ST 2022-6/7 –Encapsulated SDI complete with embedded audio
- SMPTE ST 2059 1/2 – IEEE 1588, IP Genlock and Timecode or timing reference, Black Burst for IP
- IEEE1588– PTP (Precision Time Protocol) a more precise network time reference that uses timestamp packets enabling network endpoints to generate synchronized timestamps for frame accuracy in transport applications
- VSF TR-04 – Technical Reference – SMPTE 2022-6 encapsulated with SMPTE 2059 -2
- VSF TR-03 – Technical Reference – RFC4175 with AES67 for audio and SMPTE ST 2059 1 and 2
- RFC 4175 – Request for Comments is an IETF (Internet Engineering Task Force) open format concept for IP streaming
- AES67 – Audio Engineering Society Standard for IP audio
- DANTE – Digital Audio Network Through Ethernet – Audio over IP. While Dante technology is not part of AES67, the company behind Dante, Audinate, has chosen to implement an AES67 mode as part of their interfaces.
- IS- 04 – NMOS (Networked Media Open Specifications) – discovery and registration – think of this as SNMP with a longer name.
SMPTE ST 2110 Family
- SMPTE ST 2110 -10 – Timing: SMPTE ST 2059 Parts 1 and 2
- SMPTE ST 2110 -20 – Uncompressed Video: IETF RFC 4175, VSF TR-03
- SMPTE ST 2110 -21 – Video packet shaping
- SMPTE ST 2110 -30 – PCM Digital Audio: AES67
- SMPTE ST 2110 – 40 – Ancillary Data: SMPTE ST 291, RTP
- SMPTE ST 2110 - 50 – Video: SMPTE 2022 part 6, VSF TR-04
After successful IP-technology demonstrations with multiple participating vendors at InterOp events (Interoperability Testing) and at last IBC, there was a fair amount of consensus of what the new standard for IP should include. The new standard would represent a set of common interoperable SMPTE rules for live production based on an IP stream and compatible with commercial off-the-shelf (COTS) Ethernet technology. The agreed upon philosophy was to move away from embedding signals and return to using discreet signals for each signal type – video, audio, timing and ancillary data. The standard would also provide for future technology innovations.
The early development of Live IP was challenging. To bring order to this new world SMPTE 2110 was born. After many committees, meetings and testing, a path forward was identified. Historically, all signals travelled on their own wire and had their own connectors. Switching was segregated by signal type. In this new world, the goal was to keep the signal segregated at the device but share the transport.
There were many competing concepts on which current and legacy signals should be considered and how would that work. Multiple solutions and paths were proposed: AIMS, ASPEN, NMI, VSF and NDI. Because NDI is a highly compressed format, it really belongs with J2K if comparisons are being made.
When SMPTE first introduced ST 2022 parts 1 and 2, it became affectionately known by its other name, MPEGTS. MPEGTS was happy playing in the Ethernet LAN and WAN worlds. It played in the DVB sandbox along with IPTV. ST 2022 wasn’t looking to upset the current technology, SDI, it just wanted to get along.
Introducing SMPTE 2110
There are six members of the 2110 standard’s family. Most of the siblings came from other places like IETF, AES and IEEE. Some came from the broader SMPTE family of standards. As a family, SMPTE 2110 will evolve. One can hope that as each new member (standard) is introduced, the other members of the standards family will accept them and play nicely together.
One other note is that each member of the family is now called essence. Essentially all production devices will originate and process all ST2110 essences (audio, video, timing and ancillary data). These signals will be compatible with commercial off-the-shelf commercial (COTS) Ethernet IP switching and routing equipment.
SMPTE ST – 2110-10 is timing and sync, master clock reference. This was previously called SMPTE 2059, which was first created as IEEE 1588. This provides the frame accurate time reference needed for live switching. All devices and networks will have ST 2110-10 as part of their signal complement.
SMPTE 2110 – 50 is the first member of the family. This is our old friend SDI packaged as IP in SMPTE 2022 Part 6. It includes only video, no more embedded audio or ancillary data. This is what VSF TR-04 was promoting. This is the type of signal that, for example, will be present at the output of a camera or the input to a production switcher.
SMPTE ST 2110 – 30 is the audio formerly known as AES67. Now that audio is no longer embedded in SDI or removed during the encoding process to ST 2022, the essence of audio, AES67, is what audio production devices will originate and process.
SMPTE ST 2110 – 40 is ancillary data. It represents all the ANC’s HANC, VANC and AUX, Line 21, etc. and was formerly known as SMPTE ST 291 or RTP (Real Time Protocol).
SMPTE ST 2110 – 20 is where future standards get interesting. When the video essence changes from ST 2022 part 6 to IETF RFC 4175, bowing to VSF and TR-03, we need to ask, what will this mean to all the earlier devices that were based on ST 2110-50? Will SMPTE 2110-20 be backwards compatible with SMPTE 2110-50? Or, will this be a disruptive system upgrade? Users will want to know if moving to ST 2110-20 will require another round of middleware converters or the ubiquitous gateway.
SMPTE ST 2110 – 21 video packet shaping. This is a new and positive addition. Media moving over networks put a considerable burden on the network and adding more bandwidth doesn’t solve that problem. Traffic shaping or network optimizing is a critical consideration when designing an IP infrastructure.
IS-04 has not yet been given a SMPTE 2110 designation, it is just IS-04. This is how production devices are recognized and registered in the IP ecosystem. Ultimately this will facilitate how signals know where to go and the best path to get there. When real SDN (Software Defined Networking) arrives that’s where discovery and registration will be managed, but we are not quite there yet.
This is a lot to digest and there remains a lot of standards work still underway. The next challenge is ensuring interoperability. I will address this aspect in my next article.
Questions? Ping me in the box below.
Editor’s Note: Gary Olson has a book on IP technology, “Planning and Designing the IP Broadcast Facility – A New Puzzle to Solve”, which is available at bookstores and online.
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