hat
Estasyon televizyon analog pa kapab genyen menm chanèl menm si opoze (pèpandikilè) itilize polarizasyon, akòz pwoblèm senkronizasyon videyo tankou fantom. Nan peyi Etazini an, pa gen okenn nouvo sou-chanèl ranfòse siyal UHF yo te otorize depi jiyè 11, 1975. estanda a ATSC pase ak COFDM itilize nan Ewopeyen an ak Ostralyen DVB-T estanda. Estasyon difizyon ameriken yo pa gen tradiktè oswa rapèl; menm si yon SFN se aktyèlman pi fasil yo kreye nan bann frekans yo, li se lajman nesesè kòm longèdonn yo pi long nan siyal sa yo yo pi kapab bay ase pwoteksyon sou pi long distans malgre yon mank de liy-nan-vi transmisyon kondisyon.
eng
Analog TV stations cannot have same-channel boosters unless opposite (perpendicular) polarisation is used, due to video synchronization issues such as ghosting. In the US, no new on-channel UHF signal boosters have been authorized since July 11, 1975.[1] Digital TV stations are technically capable of sharing a channel, however this is more difficult with the 8VSB modulation and invariable guard interval used in the ATSC standard than with COFDM used in the European and Australian DVB-T standard. US AM broadcasting stations do not have translators or boosters; though an SFN is actually easier to create in their frequency band, it is largely unnecessary as the longer wavelengths of these signals are more able to provide adequate coverage over longer distances despite a lack of line-of-sight transmission conditions.