- ATSC-M/H
ATSC-M/H is a future standard currently (
as of 2008 ) under consideration, to allowATSC digital television broadcast signals to be received bymobile device s. [ [http://www.atsc.org/news_information/press/2007/Mobile_07.html ATSC to Develop Standard for Mobile and Handheld Services] ]While
DVB-H and1seg were built-in to their respective standards, ATSC was never designed to servemobile TV viewers. In particular, theproprietary 8VSB modulation used causes problems withmultipath radio interference even in stationary receivers. It also lackshierarchical modulation , which in DVB allows higherscreen resolution s to be received as low-definition still suitable for handheld devices, in marginal signal conditions such as mobile reception, or at the edge of aTV station 'sbroadcast range .Ten systems were proposed, and two systems have been considered. MPH (an
acronym for [mobile] /pedestrian /handheld , andmiles per hour ), was developed byLG Electronics andHarris Broadcast . (Zenith, asubsidiary of LG, developed much of the original ATSC system.)A-VSB (Advanced-VSB ) was developed bySamsung andRohde & Schwarz . Both systems require stations to use their limitedbitrate s to duplicate programming, once for existing viewers and once for mobile viewers.While
MediaFLO has become available in parts of theU.S. , it is a completely closed and proprietary system, locked to amobile phone and itsmobile phone company , even though the signal is separate and does not use thecellular network . ATSC-M/H would befree to air , like regular broadcast signals are. However, ATSC places a greater burden on the receiving device than either MediaFLO or theopen standard DVB-H , which is also in use in the U.S.As of July 2008 , it has been decided that ATSC-M/H will be ahybrid , consisting mainly of MPH and partly of A-VSB. [http://broadcastengineering.com/products/harris-mobile-platform-albavision-0707/index.html] It does not appear thatE-VSB , approved in 2004, will be included.References
External links
* [http://gamdala.blogspot.com/2007/04/new-us-mobile-tv-standard-under.html New US Mobile TV Standard Under Development] , April 12, 2007
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