Video: BBC Cardiff Central Square – Update

It’s being closely watched throughout the industry, a long-in-the-making project to deploy SMPTE ST 2110 throughout a fully green-field development. Its failure would be a big setback for the push to a completely network-based broadcast workflow.

The BBC Cardiff Central Square project is nearing completion now and is a great example of the early-adopter approach to bringing cutting-edge, complex, large-scale projects to market. They chose a single principle vendor so that they could work closely in partnership at a time when the market for ST 2110 was very sparse. This gave them leverage over the product roadmap and allowed to the for the tight integration which would be required to bring this project to market.

Nowadays, the market for ST 2110 products continues to mature and whilst it has still quite a way to go, it has also come a long way in the past four years. Companies embarking similar projects now have a better choice of products and some may now feel they can start to pick ‘best of breed’ rather than taking the BBC approach. Whichever approach is taken there is still a lot to be gained by following and learning from the mistakes and successes of others. Fortunately, Mark Patrick, Lead Architect on the project is here to provide an update on the project.

Mark starts by giving and overview of the project, its scale and its aims. He presents the opportunities and challenges it presents and the key achievements and milestones passed to date.

Live IP has benefits and risks. Mark takes some time to explain the benefits of the flexibility and increasingly lower cost of the infrastructure and weighs them agains the the risks which include the continually developing standards and skills challenges

The progress overview names Grass Vally as the main vendor, control via BNCS having being designed and virtualised, ST 2110 network topology deployed and now the final commissioning and acceptance testing is in progress.

The media topology for the system uses an principal of an A and a B network plus a separate control network. It’s fundamentally a leaf and spine network and Mark shows how this links in to both the Grass Valley equipment but also the audio equipment via Dante and AES67. Mark takes some time to discuss the separate networks they’ve deployed for the audio part of the project, driven by compatibility issues but also within the constraints of this project, it was better to separate the networks rather than address the changes necessary to force them together.

PTP timing is discussed with a nod to the fact that PTP design can be difficult and that it can be expensive too. NMOS issues are also actively being worked on and remains an outstanding issue in terms of getting enough vendors to support it, but also having compatible systems once an implementation is deployed. This has driven the BBC to use NMOS in a more limited way than desired and creating fall-back systems.

From this we can deduce, if it wasn’t already understood, that interoperability testing is a vital aspect of the project, but Mark explains that formalised testing (i.e. IT-style automated) is really important in creating a uniform way of ensuring problems have been fully addressed and there are no regressions. ST 2110 systems are complex and fault finding can be similarly complex and time consuming.

Mark leaves us by explaining what keeps him awake at night which includes items such as lack of available test equipment, lack of single-stream UHD support and NMOS which leads him to a few comments on ST 2110 readiness such as the need for vendors to put much more effort into configuration and management tools.

Anyone with an interest in IP in broadcast will be very grateful at Mark’s, and the BBC’s, willingness to share the project’s successes and challenges in such a constructive way.

Watch now!

Speaker

Mark Patrick Mark Patrick
Lead Architect,
BBC Major Projects Infrastructure

Video: ST 2110 Test and Measurement Super Session

This IP Showcase super session consists of six presentation from six different vendors which focus on specific aspects of test or measurement that is unique for ST 2110 environment. It is worth noting that these are technology presentations, not product presentations.

The session is led by Willem Vermost from EBU. He describes what kind of issues we need to solve in a SMPTE ST 2110 environment in terms of testing and monitoring. He speaks about PTP accuracy, traffic shaping (SMPTE ST 2110-21) and SMPTE ST 2022-7 redundancy.

Next, Michael Waidson from Tektronix focuses on Precision Time Protocol (PTP) which is a cornerstone of synchronisation of IP media networks. He walks us through Best Master Clock algorithm, boundary and transparent clocks plus PTP fault finding. (You might also want to watch the Monitoring and Measuring IP Media Networks presentation by Michael which we recently published on The Broadcast Knowledge.)

Furthermore, Jack Douglass from PacketStorm talks about ST 2110-21 traffic shaping measurements. He also shows how to use network emulation tools for testing ST 2022-7 link redundancy (the same data is sent through two separate paths of network emulation that are synchronised together, then burst loss are generated using RTP sequence number, with the least important bit different on both paths).

The next speaker is Ståle Kristoffersen from Bridge Technologies. He focuses on live performance monitoring in a ST 2110 network – does the signal make sense? (IP headers, RTP headers, ST 2110-20/30/40 essences), do all of the signals arrive? (packet loss, monitoring packet loss on 2022-7 links), does the signal arrive on time? (late can be just as bad as a packet loss) amongst others.

Moreover, Kevin Salvidge from Leader shows the differences in monitoring in an SDI and an all-IP facility. He compares single essence per BNC with multiple essences per fibre, synchronous and asynchronous transport and causes for errors (cable loss and impedance mismatch vs error packet loss and network overload). He also emphasises the need for accuracy of PTP and explains how to measure it.

Last but not least, Adam Schadle from Video Clarity walk us through video / audio performance and quality methods. He shows how to use picture and sound quality objective tests to understand network behaviour.

The presentations are followed by Q&A session.

See the slides here.

Watch now!

Speakers

Willem Vermost Willem Vermost
Senior IP Media Technology Architect
EBU
Michael Waidson
Application Engineer
Tektronix
Jack Douglass
VP Marketing and Business Development
PacketStorm
Ståle Kristoffersen Ståle Kristoffersen
Lead Software Developer
Bridge Technologies
Kevin Salvidge
European Regional Development Manager
Leader
Adam Schadle
Vice President
Video Clarity

Video: Transporting ST 2110 Over WAN

Is SMPTE ST 2110 suitable for inter-site connectivity over the WAN? As ST 2110 continues to mature and the first facilities are going live bringing 2110 into daily use, there are a number of challenges still to be overcome and moving a large number of essence flows long distances and between PTP time domains is one of them.

Nevion’s Andy Rayner presents the work the VSF is doing to recommend transport of ST 2110 over WAN outlining where they have got to and what has been recommended to date.

The talk starts with SMPTE 2022-7 seamless protection which is recommended for dealing with path breaks. For compensating for transmission errors, FEC is recommended and Andy explains the parameters needed.

Key to the inter-site transport is trunking whereby the individual essences are mixed down to one flow. This has a number of advantages: Reducing the number of flows makes life simpler for service providers, all essences will now share the same signal path from site to site and it FEC protection can be more efficiently applied.

The trunks are made using GRE – Generic Routing Encapsulation – which is a pre-existing IT standard for grouping lots of traffic into a single tunnel whilst preserving the data inside. This then appears at the other end of the trunk with the same IP information as if nothing had happened. Andy looks at the extra encapsulation headers needed to make this work and goes on to discuss payload lengths as we need to keep them short so as not to result in fragmented packets.

Timing, as ever, is important meaning that the recommendation is to align all essences before sending them in to the trunk, though Andy looks at alternatives. Also of key concern is compression as there will be times when uncompressed video is simply too high a bandwidth to be carried on the WAN. JPEG 2000 and, now, JPEG XS are available for this task.

Andy covers timing, discovery, control, security and conversion to and from 2022-6 before finishing the talk by taking questions.

Watch now!
Speaker

Andy Rayner Andy Rayner
Chief Technologist,
Nevion

Video: ST 2110-30 and NMOS IS-08 — Audio Transport and Routing

Andreas Hildebrand starts by introducing 2110 and how it works in terms of sending the essences separately using multicast IP. This talk focusses on the ability of audio-only devices to subscribe to the audio streams without needing the video streams. Andreas then goes on to introduce AES67 which is a standard defining interoperability for audio defining timing, session description, encoding, QOS, transport and much more. Of all the things which are defined in AES67, discovery was deliberately not included and Andreas explains why.

Within SMPTE 2110, there are constraints added to AES67 under the sub-standard 2110-30. The different categories A, B and C (and their X counterparts) are explained in terms how how many audios are defined and the sample lengths with their implications detailed.

As for discovery and other aspects of creating a working system, Andreas looks towards AMWA’s NMOS suite summarising the specifications for Discovery & Registration, Connection Management, Network Control, Event & Tally, Audio Channel Mapping. It’s the latter which is the focus of the last part of this talk.

IS-08 defines a way of defining input and output blocks allowing a channel mapping to be defined. Using IS-05, we can determine which source stream should connect to which destination device. Then IS-08 gives the capability to determine which of the audios within this stream can be mapped to the output(s) of the receiving device and on top of this allows mapping from multiple received streams into the output(s) of one device. The talk then finishes with a deeper look at this process including where example code can be found.

Watch now!

Speaker

Andreas Hildebrand Andreas Hildebrand
Senior Product Manager,
ALC NetworX