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Holding cable TV signals accountable to DTV carriage agreements

For years over-the-air broadcasters have complained that the local cable company carrying their signal was reducing the bit rate, and thus the on-air quality, of their high-definition channel when delivering it to subscribers. Triveni Digital — a subsidiary of LG Electronics that develops and markets broadcast stream analysis products — can prove it using specific data stream information about a television signal. (Of course, simply hooking up an antenna to a DTV set often reveals the difference in picture quality between the cable and off-air signals to the naked eye.)

Indeed, many are saying that all new carriage agreements should have clauses to determine at what bit rate a particular channel will be delivered into subscribers’ homes. To date, some cable operators, in an effort to conserve bandwidth for more channels, have “stomped on” broadcasters’ channels. With the industry’s move to digital broadcasting, this has been less of an issue, but there’s still no industry standard way of delivering HD content over a cable system. It’s left to the cable operator’s discretion, and broadcasters have little recourse.

“Terrestrial broadcasters have a easy and quantifiable way to hold cable operators to their carriage agreements, and they should,” said Ralph Bachofen, vice president of sales and head of marketing at Triveni Digital. “Stations should specify specific guidelines and thresholds for their HD channel when they sign carriage contracts, and they then need to monitor their channel closely after it is passed through the local cable or satellite TV service to see if it complies.”

The company’s StreamScope RM-40 stream monitoring appliance offers a series of digital video troubleshooting tools to help engineers isolate a problem (e.g., dropouts, uneven audio levels, image freezing or no picture at all) within an ATSC digital broadcast stream and make appropriate corrections to fix it. The system is designed to remotely monitor, measure, record and analyze digital broadcast streams in order to ensure compliance with the ATSC DTV specification and with whatever guidelines a particular station might have to ensure the highest quality.

It does this via an Automated Stream Comparison feature that gives stations the proof they need to ensure that signal quality, services and components are in line with business or contractual agreements. By automating this process, the RM-40 allows straightforward DTV carriage auditing and, in turn, faster resolution of impairments to the signals ultimately delivered to the viewer.

The latest software (v2.0) for the StreamScope RM-40 are Live Services Monitor and thumbnail views that make it easy to see if there’s a video picture present with a quick glance. Also, closed-captioning data decoding — with rule-based alerts — has been added to simplify operations and reduce the manual workload necessary to maintain required closed-captioning information. The RM-40 is part of a line of products that range from low-cost rack-mounted 1RU boxes to a high-end router embedded StreamScope eRM application available from Juniper Networks.

The new software also supports decoding of Active Format Description (AFD) data to indicate the proper aspect ratio conversions between formats. Automatic transport-type detection allows rule clusters to be applied based on transport type (MPEG-only, ATSC, DVB-SI, etc.). The software also includes improved stream status reporting. If the encryption state changes, or if anticipated messages such as SCTE-35 messages for digital program insertion (DPI) do not arrive, the system immediately alerts the operator.

These real-time monitoring and alert capabilities can also be valuable in DTV carriage auditing and in maintaining service level agreements.