Triple-Play Service Deployment

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Troubleshooting Video in the Headend
Over a decade ago, the advent of digital television in the broadcast
industry prompted a complete paradigm shift in both broadcast
equipment and test practices. What once was a linear, continuous
analog signal became a fragmented, nonlinear string of digital
packetized data that contained a fraction of the original video
information. Modulators were pushed to the perimeter of the
broadcast rack—almost an afterthought to digital broadcast’s
essential digital encoders and multiplexers. The antenna and
television found their once direct union completely separated by
a revolutionary device—the set top box. The network itself
effectively went “dark”because programs were no longer visible at
any point in the broadcast chain—they were hidden in transport
streams, obscured by MPEG, ATSC, and/or DVB transport protocols.
Technicians managing this network learned to rely on
sophisticated test equipment more like protocol analyzers than
video monitors or RF devices. The broadcast video network
transformed into one that looked more like an IP network.
Monitoring and troubleshooting this network required a new
approach that carried with it a steep learning curve.
Today, digital television service delivery is again prompting
sweeping changes as traditional telecom service providers
strategize to include IPTV in their triple-play service offerings.
Bundled service delivery is bringing with it a new class of test
equipment and supporting test methods. While telecommunication
networks historically have relied on protocol analysis for
efficient packet-based transport, IPTV delivery introduces new
challenges and considerations. Delivery of packet-based video
over these networks is not necessarily a natural progression.
Examined more deeply, IPTV service delivery entails more than the
primary obstacle of getting the sheer volume of video payloads