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Tandberg Addresses Non-Linear MediaPath Capabilities, MPEG-4 Transition Challenges

By | January 16, 2009
      [Satellite News 01-16-09] Tandberg Television kicked off 2009 with a content delivery deal with Starz Entertainment intended to promote Tandberg’s next-generation MediaPath system as a non-linear distribution platform, Tandberg Vice President of business development, Lisa Hobbs told Satellite News.
          "We are trying to make the market understand that while the next-generation MediaPath has, to date, been used solely for distribution of video-on-demand (VOD) content, any non-linear content can be distributed using that mechanism," said Hobbs.
          Non-linear content includes advertising, music and games, which Tandberg, in an effort to expand its customer base, is interested in distributing. "The first system was very specifically geared toward cable VOD specifications. This system is much more open and we do want more customers and perspective customers to understand that if they have any type of non-linear content that needs to be distributed to many different locations, that MediaPath is in fact, a viable option for them," said Hobbs.
          Tandberg’s plans to roll out with a diverse content distribution platform also centers on how efficiently the company manages its bandwidth. Tandberg is managing their satellite transmissions with a two-fold solution that yields 20 percent to 30 percent more bandwidth efficiency, said Hobbs. The first part of that system is DVB-S2 modulation technology, which not only allows for more bits to be packed into the same bandwidth but also creates increased margins on the satellite link. "If our customers have been operating on the edge of a satellite link, they can give themselves more of a buffer to make sure they maintain their signals," she said.
          The second part of the system is an optional add-on dubbed Prekor, a digital pre-correction technology. "When you just use DVB-S2 technology, and especially if you use the higher-order modulation schemes, what you end up finding is that there are distortions on the satellite transponder," said Hobbs. "Non-linearity is then introduced to the transmission. Those non-linearities can translate into a reduction in the amount of bits available for use. So we can linearize the transponder for the transmissions as a digital pre-correction. It is something that is only done on the uplink. It doesn’t impact any downlink receiver at all and also adds to the increased efficiency of the transmission."
          For now, the bread and butter for the next-generation MediaPath system is VOD distribution services, a platform for which Tandberg won industry awards from the Technology and Engineering Emmys in 2008. "Clearly, [VOD] has changed the way Americans watch television," said Hobbs, "Especially in a time of an economic downturn, where consumers spend more time at home and view pay-TV as a necessity more than a luxury."
          Tandberg has also recently won an HDTV award, in conjunction with DirecTV, for the development of its MPEG-4AVC system. The transition to MPEG-4 has provided several growth opportunities, as well as some tough challenges, for Tandberg.
          Hobbs said that transitioning from MPEG-2 to MPEG-4 affects programmers and broadcast networks differently. For programmers, whose target audience is U.S. cable headend sets that can only handle MPEG-2 transmissions, the transition can be expensive. "From a technology perspective, the switch to MPEG-4 saves the programmers money, but it means that a more expensive receiver device at the headend will need to transcode that video from MPEG-4 back to MPEG-2 so that the cable operators can use it," said Hobbs. "If they are targeting a telecom headend and they are already using MPEG-4, they won’t have that same issue." 
          For the telecoms, issues over what bit rate is coming over satellite and whether that bit rate can be used by the telecom become a concern. "They would have to figure out what kind of trans-rating has to be done to lower the bit rate if necessary," said Hobbs. "Programmers are having to weigh the financial savings from potentially using less transponder capacity for the same amount of data by going to MPEG-4 versus the higher cost of the headend for the receiving equipment."
          For broadcast networks, the transition problems are a little easier to solve, said Hobbs. "Because of all the local content that has to be inserted into the stream and then re-encoded at the station level, it is a little bit easier because they always decode back to an uncompressed signal anyway. So from their perspective, they simply needed a new receiver to be sent out," she said.
          Consistency of signal quality is the biggest concern for broadcast networks as well as, according to Hobbs, "maintaining what they consider to be true broadcast quality so that the consumer at home would not be able to discern any difference whatsoever in the video quality before the transition to MPEG-4, as opposed to after."

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