Despite the onus of being parceled up and sold off to Time Warner Cable and Comcast, Adelphia has forged ahead this year with its digital simulcast plans.
Basil Badawiyeh, Adelphia's manager of advanced video engineering and development, said Adelphia will be in eight to 10 markets, which represent 5 million homes passed, by the end of the year.
"As part of migrating to the digital domain, we're using a couple of things," Badawiyeh said. "One of them is called open-loop encoders, and the other is closed-loop encoders. The difference between the two is that the open-loop encoder is usually a single task, analog on one side, or baseband, and MPEG-2 on the other side. It's a one-pass type device that converts things into the MPEG-2 domain."
"For the closed-loop encoders, we have multiples of them, in general 14, and they're interconnected into a single statistical multiplexer, which makes up the closed-loop encoding solution. The advantage of that solution is that you have certain settings for how you want particular analog content encoded. When the encoders do their job, MPEG-2 comes out on the output side that goes into the statistical multiplexer."
At the next stage, the statistical multiplexer looks at the video bit rates and the complexity in all 14 encoders and compares them against each other. If there is one piece of content that can get by with fewer bits, the statistical multiplexer robs those bits and gives them to a piece of content that needs more. Then the statistical multiplexer gives that information back to the encoders, which then re-encode the content based on the new information.
"The output of this entire process is a very efficient 14 or 16 services on a QAM-256 multiplex," Badawiyeh said. "That's how we gain efficiency on bandwidth, as well as a lot of video quality improvements with the better front end processing that is associated with these encoders and that system."
Adelphia slated its over-the-air core channelsthe most watched channels such as CBS, NBC, etc.to go through the closed loop solutions.
Adelphia uses Harmonic, Motorola, EGT and Scientific-Atlanta for its encoders, and Terayon and BigBand for the statistical multiplexers. RGB Networks and VCom are the decoder vendors.
"We wanted to make sure we got out of the gate with the best video quality possible on those channels," Badawiyeh said. "As far as numbers, we have about 28 services in each of our five regions. In Los Angeles, we have four super headends, two primaries and two secondaries, so we have set of 28 in two locations because we're running things in a redundant configuration."
Tracking video content
Adelphia has large regional transport rings in each of its five regions that are Gigabit Ethernet-based, and currently it's in the process of attempting to identity the video quality of a piece of video content as it runs from the East Coast to the West Coast.
"The reason this is attractive to us is because we don't want to have to go in and encode a common piece of content five different times," Badawiyeh said. "If it's common across everyone, then we can further augment it based on that specific region's needs. We can encode it once and then ship it across our backbone network, which covers the East Coast to the West Coast.
"It's a lot cheaper and it allows us to eliminate a lot of redundant hardware. It's easer to manage because we have centralization in a way we haven't had before."