DirecTV hasn't said what new channels it plans to add later this year to bring its HDTV total up to 100. But competitors say they doubt the satellite operator will be able to find many more HDTV channels worth watching. Some of the HDTV channels that DirecTV offers today don't give it much of a competitive advantage. For example, the satellite operator offers both an East Coast and a West Coast transmission of HBO, meaning a subscriber can watch programs like "The Sopranos" at two different times. But DirecTV does offer a number of popular networks on HD that most cable systems don't. For example, Comcast's flagship system in Philadelphia, its headquarters city, doesn't offer channels such as Bravo, Animal Planet, USA Network, the History Channel and the Weather Channel on high-definition. DirecTV does. Meanwhile, in rural areas, DirecTV subscribers can watch high-definition broadcasts of major networks like CBS and ABC from Los Angeles and New York when local affiliates don't broadcast in HD.