Lowering the cost of broadcast channel delivery
May 1, 2011 12:00 PM, BY JOHN WADLE
Switching to an IT/software-based system reduces complexity and increases flexibility.
Broadcasting has passed a key milestone where many processes, formerly based heavily on specialized hardware components, are now more focused on generic IT components. The emergence of IT as a key platform for new broadcast systems has not only defined a new direction for stations, but is also changing the mix of system providers as well. As a result, broadcasters today have a wide selection of products available, spanning conventional broadcast hardware, IT/software-based systems and hybrids that combine both technologies.
Broadcast workflow
The adoption of IT-based systems has changed the broadcast workflow in a predictable way. Upstream processes, such as content production, provided a lower-risk opportunity for the introduction of the new file-based workflows with “all software” editing systems operating on standard IT workstations. Scheduling (traffic) and program management systems followed on their own parallel path, moving from older mainframe or minicomputer systems to modern IT client-server architectures. (See Figure 1.)
Figure 1. A typical IT-based broadcast workfl ow
An obvious next step in the progression of IT within broadcast was content acquisition. The advent of video servers and content delivery services opened the door to file-based systems that leveraged existing IT tools.
These three processes — production, scheduling and content acquisition — cover much of the broadcast workflow, and all have been largely moved to IT-based systems. The next process, transmission, is a real-time function that requires IT performance based on the latest generation of processors and bus architectures. With the availability of multicore processors, DSP extensions and enhanced PCI bus speeds, real-time, frame-accurate video/audio processing on standard IT hardware is well within reach.
For linear transmission (scheduled playout), broadcasters have been cautious in adopting major technology changes for this unforgiving process on which their revenue depends. Simply stated, during transmission there are no “do-overs.” A spot lost due to a transmission system failure is time and revenue that cannot be recovered. As a result, the transmission process has been the last frontier for IT/software-based systems in the broadcast workflow. At the same time, it is the process that offers the most potential for cost saving with a more efficient system.
Software-based system
The advantages of moving the signal processing to a software process are compelling. Most significant is a dramatic reduction in complexity, coupled with increased flexibility to accommodate new requirements. (See Figure 2 on page 44.) These benefits are seen in several ways:
Fewer hardware components requiring less rack space, power and cooling;
Fewer connections among separate components, reducing possible points of failure;
Enhanced flexibility via “plug-in” software modules, and the scalability of IT hardware;
Enhanced integration with other IT-based systems with standard technologies such as XML Web services;
An open platform with available software tools for implementation of new features and custom enhancements.
Cost of transmission
The cost of a transmission system includes both capital and operating costs, offset by potential new revenues from added or upgraded channels.
The capital costs for equipment, software, installation and training are usually well-defined by vendors, and can generally be held within budget by careful planning and execution.
Figure 2. A single-channel IT-based transmission system
Operating costs for a transmission system include predictable, recurring costs such as space, power and cooling. Human resources costs including operations, engineering and management are likewise predictable after the initial start-up period or transition. However, the magnitude of all these operational costs is directly affected by the physical and operational complexity of the transmission system.
Comparing the costs between a conventional and an IT/software-based transmission system requires a detailed assessment of the capacity, redundancy and features required for the services to be hosted. Some questions include: How many channels? SD or HD? Full redundancy, N+1 or none? How much content must be stored? Is the pass-through of satellite or live sources required? What graphics and branding are required? Are there requirements for Dolby or multilanguage audio? What about closed captions?
Each of these capabilities requires associated hardware and/or software components. Moreover, the requirements may be different for each channel, even if all channels are hosted on the same multichannel transmission system. As a result, the configuration and pricing of a multichannel transmission system is a complex process.
Nevertheless, it is possible to compare the base (infrastructure) and incremental (per channel) costs of alternative systems for a typical set of requirements. Such a comparison can provide the approximate relative costs of these two system alternatives.
As an example, we can define the requirements for a multichannel transmission system to include the following capabilities for each channel:
HD transmission (1080i or 720p);
Redundant (mirrored) playout of content;
Video mix effects (transitions);
Two-dimension DVE (squeezebacks);
Logo insertion with animations;
Text overlays and crawls;
Dolby Digital audio (AC-3);
Closed caption insertion.
These requirements define typical full-featured channels, although additional demands such as multilanguage audio, 3-D graphics and SCTE triggering are not uncommon.
Based on these stipulated requirements, we can project both the capital costs and operating resource requirements (space and power) for conventional, hardware-based and IT/software-based transmission systems.
For an example, consider currently available hardware and software systems. To simplify the example, components such as routers and shared content storage common to both systems are excluded from the comparisons.
In this comparison, the IT/software-based system provides a lower acquisition cost at list prices. More significantly, the IT/software-based system requires significantly less space and power for its operation. This results in lower ongoing costs for floor space, power and cooling.
While this comparison is generic and based on assumptions that will likely differ for any specific transmission facility, the resultant operating resource reductions provided by an IT/software-based system compared with a conventional hardware-based system are significant. This means a substantially improved return on investment (ROI) for new channel deployments.
Adapting to new requirements
Beyond these quantifiable costs, one of the potential cost implications of a new transmission system is its ability to support new service requirements. These changes might include upgrading existing channels from SD to HD or the addition of secondary DTV, mobile or Web channels. In each case, a low-cost expansion of an existing transmission system is the optimal system, but limitations in system scalability or feature set — or the requirement for costly new hardware — can make this option unfeasible.
This leaves two options: install additional transmission system(s) dedicated to the new services, or cancel plans for new services and forgo the potential revenue. Either of these choices has an associated opportunity cost incurred as a result of a transmission system's limitations.
This means adaptability should be a major criterion in choosing a new transmission system. In this context, IT/software-based systems have inherent technology benefits that provide the flexibility to adapt to new requirements more quickly and at less cost than conventional systems. These include:
Adding a new channel by installing one or two extra 1RU servers and software;
Upgrading an existing SD channel to HD with only a simple software reconfiguration;
Adding new features such as DVE or Dolby audio through software plug-ins.
In today's changing broadcast landscape, the true ROI for a transmission system includes more than the basic costs of deployment and operation. Because traditional advertising revenues continue to be under pressure, broadcasters must find new ways to reduce costs and to enhance and expand services. The cost-effectiveness and adaptability of your playout system are an essential component to this objective.
John Wadle is director sales engineering at Miranda Technologies.
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