 A hundred-kW analog station on TV channels 2 to 6 would therefore be faced with the choice of either lowering its power by 80% (to the twenty kilowatt limit of low-VHF DTV) or abandoning a frequency which it occupied since the 1950s in order to transmit more power (up to 1000 kW) on the less-crowded UHF TV band.Such stations can keep the same channel number, however, because of ATSC virtual channels.Unfortunately, the higher frequencies are challenged in areas where signals must travel great distances or encounter significant terrestrial obstacles.