IP has brought innovation to programme makers and viewers, but do the benefits outweigh concerns about the effort required to make a broadcast-ready network, asks regular IBC365 columnist John Maxwell Hobbs.
This year’s IBC and NAB shows were full of vendors touting their latest IP-based products. With major broadcasters around the world in various stages of rolling out shiny new all IP facilities, we’re clearly experiencing a gold rush, a watershed moment, a tipping point, a paradigm shift – choose your favourite metaphor for radical change.
IP has brought flexibility, innovation, and promise to an industry in transition. It’s also creating significant concern in areas such as unpredictable latency, complex system interactions, and security vulnerability.
Sometimes all the mitigation being put in place to address these issues begins to feel as if we are spending a huge amount of time, effort, and money to force IP to behave exactly like SDI.
The move to IP feels like a natural progression from the move to digital that began in 1986 with the D1 videotape format, but is that actually the case?
The steps taken in the transition of the production and transmission workflow have primarily been to solve longstanding problems. The move to digital videotape solved the problem of the generation loss inherent in editing and duplicating.
Disk-based digital audio and video enabled practical, affordable non-linear editing, and very importantly, allowed for non-destructive editing without the having to deal with the compromise of generation loss.
IP: the superior option?
The move to widespread adoption of HD was made possible by the image compression schemes afforded by digital video. Analogue HD transmission required a minimum of four times the amount of spectrum required by analogue SD, so it was impractical for over the air transmission. Digital transmission then made it possible to not only deliver HD signals, but to also deliver far more channels than was practical with analogue.
And now we come to IP.
As we now have all our media in file format, it’s only natural to move them around using the most common digital networking protocol, right? However, the use of IP networks for this purpose was not necessarily fait accompli.
As a matter of fact, throughout the 1990s and into the early 2000s, the smart money was on ATM (Asynchronous Transfer Mode) as the network protocol of choice for digital media. It offered configurable QoS, (Quality of Service) predictable latency, multicasting, flexibility, and high levels of security. In fact, a significant number of xDSL broadband networks still use ATM to deliver IP services to subscribers.
On paper, ATM is arguably superior to IP in many ways, particularly in the ways a data network is used for media.
”There’s no doubt that IP-based broadcasting workflows will be successful but we have to acknowledge it’s not going to be a smooth ride”
So, how did we end up with IP instead of ATM? Simple – the market made the decision for us. But it was the IT market and not the media market that made it - it’s a legacy of the dotcom boom of the late 1990s. Broadcasting’s embracing the world of IT means that we must play by Silicon Valley’s rules now, and that means embracing IP as well.
IPs big advantage is that it’s a dumb network – it does one thing, moves data packets, and it doesn’t care what those packets contain or how they’re going to be used. This means that all logic and functionality is implemented in the applications that sit on the network.
This allows for the almost instantaneous rollout of new services without requiring any reconfiguration of the existing network. All you need to do is keep throwing more bandwidth at it to support all traffic coming from the new services.
With the rough and ready ethos of “move fast and break things” driving internet businesses, it’s easy to see how this sort of a network gained traction. ATM, on the other hand, uses a virtual circuit model which requires all new services to be provisioned. This is far more efficient because the virtual circuits are guaranteed to be fit for purpose, but it’s a much more expensive network to operate, requiring more engineering expertise to run.
Read more Making the case for investment in IP
Compared to IP networks, the provisioning needed in an ATM network is perceived as a hindrance to the rapid deployment of new services. Essentially, ATM is a network engineer’s dream, while IP is a product developer’s dream.
It’s clear that IP has brought a lot of amazing innovation to broadcasting, for both viewers and programme makers – catch up and OTT services, on the fly newsgathering using mobile data networks, live contribution over consumer-grade xDSL connections - even email and instant messaging have revolutionised the way we work. But we have to ask ourselves – just because something is good for a number of things, is it actually good for everything?
The efforts that are required to make an IP network meet the reliability and security needed for broadcast workflows – VPNs, encryption, multi-factor authentication, QoS schemes, buffers, proxies, and gateways – begin to look like the sort of engineering effort required to manage ATM networks and seriously compromise the ability to “move fast and break things.”
There’s no doubt that IP-based broadcasting workflows will ultimately be successful - we’re too far down that road to turn back - but we have to be truthful with ourselves and acknowledge that it’s not going to be a smooth ride.
As well as being a music producer and composer, John Maxwell Hobbs is a course leader at the National Film and Television School, media consultant and the former Head of Technology at BBC Scotland.