Over the next few years, we will all hear a lot about “packet-based facilities” or the “all-IP plant.” It seems like the next big thing, but really this is just the continuation of a long, steady migration that has been going on since the late 1990s.
There is no question that IT technology has slowly taken a strong foothold in broadcast plants over the past decade. Previous to this, it was considered only for financial and administrative tools — certainly not for on-air operations, much less studio and production work. Both NLEs and video servers were radical shifts for broadcasters to not only grasp, but also trust since they use IT technology. (See Figure 1.)
At the same time, the broadcast world was wrestling with consolidating multiple functions into the baseband router that historically were performed by external equipment. Analog-to-digital audio and video conversion equipment was integrated into the core I/O of the broadcast router. Coaxial and fiber interfaces are equally available to provide for any desired connectivity. Mux/demux technology allows the creation of embedded audio infrastructures with the functionality of discrete audio plants. Integration of multiviewers into the core capability of the router functionality produced a radical shift in the design of monitor walls and how they were used.
Video-over-IP first began with compressed video, typically in bit rates suitable for consumer delivery of SD video signals using MPEG-2 (around 3Mb/s). At these rates, consumer television services could be offered over ADSL technology, and telecom operators in many areas began offering consumer services based on SD and MPEG-2. Supercomm in 1999 featured demonstrations of this technology from several vendors. The deployment of HDTV in the U.S. actually slowed down ADSL-based video, as ADSL technology needed to evolve enough bandwidth for HD services to homes; H.264 compression also helped to close that gap through increased coding efficiency.
The rise of digital cable TV deployments in the late 1990s provided a large digital pipe to the home. While not IP-based in the (256QAM) delivery system, the digital cable infrastructure drove a need for switching and routing of compressed video signals into every cable headend and many satellite uplink infrastructures as well. These headends began with vendor-specific bespoke interfaces but rapidly evolved to standards-based TS over IP in order to save cost and provide interoperability among vendors.
Today, most compressed video signals in headends worldwide (IPTV, digital cable, satellite and even digital terrestrial broadcasters) are switched, routed and transported using RFC2250/SMPTE 2022-formatted data over IP on Ethernet. This is now regarded as a mature stable technology with high reliability and reasonable cost structure, and coaxial DVB-ASI is relegated to special cases and test equipment.
Meanwhile, over the past 10 years, Ethernet interfaces and their related packet switching technologies have undergone extreme capability growth. Twelve years ago, GigE was mostly on fiber, and fairly expensive. Today, 10GigE on Cat 6A copper is widely available, and highly capable Ethernet switches with hundreds of 10GigE ports are available from multiple vendors at reasonable (for what they are) prices. Fiber-based 40Gb/s — and even 100GigE interfaces — are available in these same switches. This capability growth, and the large marketplace of high-capacity switches, is driven by the rise of large-scale datacenters and cloud/virtualization centers, a demand generator that is larger than the broadcast equipment industry and likely to continue for many years.