19 February 2016
Written by IABM APAC Director Peter Bruce
This article originally appeared on the APB Website, click here to view
The computer industry has been eyeing the broadcast and media technology sectors for many years and asking why the baseband guys have avoided the IP world for so long. The wider world of moving data has long been dominated by IP, in which routing and connectivity are managed by standard IT solutions. So why has baseband video escaped for so long?
Let’s look at the initial problems of moving from our beloved 75-ohm coax cable to a twisted pair IP workflow. The reason the move has taken so long is because of not only a deep suspicion based on past bitter experience of anything IT from the hardened broadcast engineer, but also real and perceived limitations of IT-based solutions.
Reaching the limits
There is some justification for this mistrust — engineers are being asked to move from the reassurance of a solid point-to-point cable to the world of “IP addresses” and “pinging”, in which the signal will move into the unknown — and the undeterministic!
Moreover, there have historically been limitations in IT technology compared to the dedicated hardware that the broadcast supplier has been providing. The problem was that when IT routers were boasting 100Mbps speeds, the SDI digital stream was far ahead at 270Mbps. Then, as the next generation of affordably priced IP routers were offering 1Gbps, the HD-SDI stream raised its game to 1.5Gbps and 3Gbps.
Now, 10Gbps IP routers are where the 1Gbps routers were only a few years ago, and this certainly meets the requirement for HD routing.
But now that the world is starting to eye up 4K/Ultra HD (UHD) video signals, and 12Gbps to deliver 4K/UHD uncompressed video, this is now beginning to exceed the capabilities of the broadcaster’s coax cable — and is also beyond current generation IP switches.
The real cost
At Inter BEE 2015 in Japan, it was clear from what many exhibitors were promoting that the move to IP workflows is happening. However, as 4K/UHD is starting to be implemented, there was also a clear and apparent movement to retain traditional workflows, with many solutions promoting 12G-SDI interfaces.
It is clear that at this data rate — pushing the “envelope”, or in this case “Bit Error Rate”, down an SDI cable — is starting to test the limits of the beloved baseband cable.
Meanwhile, the IP world is preparing itself for 40/100Gbps and on to 250Gbps. But when broadcast project managers look at implementing IP workflows, they are often surprised that the expected cost benefits are not always there.
There are several reasons for this. As we are still living in a hybrid world, often the IP network must live alongside the baseband and those interfaces cost money; professional IP routing solutions are also not yet at the price point that broadcast engineers might have been led to believe.
The standards question
Additionally, the debate on IP standards has not yet settled, with some of the major players forming AIMS, (the Alliance for IP Media Solutions) supporting VSF TR-03/-04, SMPTE 2022-6 and AES67 standards, while other manufacturers go their own way, especially if they are looking to supply 4K/UHD-ready solutions. This causes the broadcast project manager to hold off and stick with what they know, until a clear direction can be established.
Many manufacturers and solutions suppliers in the broadcast world are promoting the IP route. I have no doubt of the long-term benefits for IP routing. However, before you start sending the broadcast signal down the IP line, you must review the technical requirements, costs, interoperability and change of workflow benefits. Once it all stacks up for your project, then it is the right time to move on to the IT/IP world.