Broadcast technology – media distribution using Internet Protocol (IP) Networks


“The future of all communications is here, and its name is Internet Protocol.”

“…the move away from SDI to IP-based workflows isn’t only about a single specification or industry-imposed technology like the move to 4K. It’s also about a fundamental change in the way video is produced.”

For the past few decades, the television industry has been dominated by two major technology transitions. In the 1980’s it was the transition from analogue to digital video signals. A decade later the move from Standard Definition (SD) to High Definition (HD) began. Following the turmoil of these transitions, the television industry is now faced with a third technology upheaval: migrating from SDI to IP-based studio infrastructure quickly, cost effectively and within a common standard.

The future of all communications is here, and its name is Internet Protocol (IP). Originally regarded as an IT-only transport technology suitable for data and email traffic, IP has quickly become the dominant standard for all types of communications. This change is largely due to the inherent flexibility of IP transport, its cost efficiencies and the universal availability of IP networks. Traditionally, broadcasters had been reluctant to consider IP technology for “mission critical” real-time video services. While IP networks have played a role in contribution and production processes, they were typically reserved for non-real-time applications and there were many vendors developing their own protocols. Today, IP network technology has evolved, and concerns about its ability to support the stringent quality and resiliency demands of real-time video have been addressed. As a result, IP has emerged as a viable technology, and IP-based transport networks are finally being adopted by broadcasters and production services around the globe.

2017 should go down in history as a watershed year for broadcasting. Since its inception there has been division between working groups, equipment vendors and broadcasters alike as to which standard of IP should be adopted and a battle of control had arisen that threatened to stall the implementation of a common working method. Out of the blue, the fairies of good reason waved their magic wands at NAB 2017 and suddenly there were open talks about compatibility and harmony between all the main user groups with the Alliance for IP Media Solutions (AIMS) coming out the clear leader. Finally, the industry agrees, to adopt a set of open standards, (documented as SMPTE 2110) that broadcast and media companies can use to move from legacy Serial Digital Interface (SDI) systems to a virtualised, IP-based future—quickly and profitably.

Behind the scenes

For many years now, SDI has been the common standard for transporting uncompressed video within facilities, and has allowed post-production companies and broadcasters to connect equipment together via routers and switchers. When IP contribution emerged, standards were agreed for the transport of SDI signals over IP – most notably the Society of Motion Picture and Television Engineers (SMPTE) 2022 standards for transport and protection, and the JPEG and MPEG standards for compression. As a result, IP contribution networks can feature a variety of equipment from different vendors with seamless integration and operability. As IP made in-roads into the studios, it became necessary for the industry to agree on standards that will provide that same flexibility all round and avoid vendor lock-ins. The Video Services Forum (VSF), with the support of organisations such as SMPTE and the European Broadcasting Union (EBU) jointly worked hard on developing a series of technical recommendations for standards that would ensure full interoperability over IP. SMPTE began work in January 2016 to develop a complete set of standards specifying the carriage, synchronisation, and description of separate elementary essence streams over IP, based on the VSF Technical Recommendations, resulting in it being documented as SMPTE 2110.

Delivering Next Generation IP-based Post Production Studios

Thanks to the SDI-to-IP bridging support provided by SMPTE 2110, broadcasters and production houses alike can take an incremental approach of the IP transition by building new islands of IP-centric operations while continuing to rely on legacy equipment elsewhere. It’s a scary journey, with many opposing the idea just as vehemently as those who opposed the move away from tape-based workflows with the advent of file-based workflows. Today, tape hardly exits at all. And like that example, the move away from SDI to IP-based workflows isn’t only about a single specification or industry-imposed technology like the move to 4K. It’s also about a fundamental change in the way video is produced. Many people in our industry view the difference between SDI and IP as just replacing one cable for another, they both essentially connect something to something else in a workflow. But an IP workflow is far, far more than that. SDI can only run parallel to, but cannot talk directly to other devices connected on a network whereas IP makes your production house part of a network infrastructure that is technically connected to every computer and cell phone in the world and more – even the facility light bulbs can be connected and controlled on the same network! One of the greatest motivators for choosing IP-based routing is to accommodate 4K production. Currently it takes four HD-SDI cables to carry a single 4K signal. A single 10Gb Ethernet cable can take that same signal with a light compression. 40Gb and 100Gb interoperable switches are being developed now that would enable even more signals or greater resolutions.

This advancement in interoperability is especially timely as the industry prepares to adopt next-generation formats such as Ultra HD (4K), UHD-HDR and 1080p HDR as successors to HD formats. As a format-independent superset of multiple protocols, SMPTE 2110 is ideally suited for production of any video format, including flows enhanced with any of the HDR formats. It’s also important to note that SMPTE 2110 has been designed to accommodate 8K UHD whenever the market is ready to move in that direction.

IP beyond 4k

IP infrastructure development leaders Sony have shown their development strengths whilst working with NHK (Japan) on 8K IP outside broadcast vans for the 2020 Olympics to be held in Japan, and pushing the boundaries further, the Poznań Supercomputing and Networking Center in Poland has installed a unique system to do IP-based 8K 3D production as a reference laboratory and experimental space for UHD technology. It has built a 17,382km 100Gbps test optical loop, making it possible to simulate real applications of 8K 3D live transmission, consuming only 30Gbps of bandwidth with only 85ms delay.

How long to switch over?

So, the technology is there but unlike the switch from SD to HD there is no mandate by any government or organisation that is compelling anyone to make the switch to IP in a hurry. In real terms, no broadcaster is going to move from traditional coax-based SDI infrastructure to IP overnight. SDI is simply too embedded — there is a lot of SDI gear in the field, from cameras to switchers to routers, production and playout applications. Just like moving from analogue to digital and from SD to HD, in each case, most broadcasters constructed islands of the new technology and routed appropriate workflows into and out of them. Media over IP will be no exception. While the HD transition began for many in 1998, it is just wrapping up in some places almost 19 years later. The transition to IP, given the rapidly decreasing cost of development of new technology, should take a lot less time, some even predicting it will be accomplished in or under five years.

Of interest to me is that this major technology shift has merged the disciplines of broadcast engineering and IT, requiring cross functional skills and knowledge from both sectors and is sure to keep the industry very busy for many years to come. Today, there isn’t a camera, production switcher, standards convertor, audio mixer or lighting system that doesn’t have IP connectivity. The move away from proprietary and bespoke broadcast technology will eventually change the approach for many types of productions, creating new workflows that until now have been difficult to envision: control room in London, studio in Cape Town, recording facility in LA – no problem, thanks to Internet Protocol and those clever engineers who think in ones and zeros.


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