▁to ▁data ▁support . ▁( Ph ase ▁ 1 ▁P 2 5 ▁radio ▁systems ▁operate ▁in ▁a ▁ 1 2 . 5   k Hz ▁analog ue , ▁digital ▁or ▁mixed ▁mode , ▁and ▁ ▁P 2 5 ▁Ph ase ▁II ▁will ▁use ▁a ▁ 2 - times lot ▁T D MA ▁structure ▁in ▁ 1 2 . 5   k Hz ▁channels . ▁ ▁Currently , ▁ ▁P 2 5 ▁deployed ▁to ▁more ▁than ▁ 5 3 ▁countries ▁and ▁T ET RA ▁deployed ▁to ▁more ▁than ▁ 1 1 4 ▁countries . ▁ ▁See ▁also ▁▁ ▁Digital ▁mobile ▁radio , ▁a ▁T D MA ▁digital ▁radio ▁standard ▁from ▁E T SI ▁ ▁Digital ▁private ▁mobile ▁radio , ▁an ▁F D MA ▁digital ▁radio ▁standard ▁from ▁E T SI ▁ ▁N X DN , ▁a ▁two - way ▁F D MA ▁digital ▁radio ▁protocol ▁from ▁I com ▁and ▁J VC ▁Ken wood ▁ ▁P 2 5 , ▁( project ▁ 2 5 ) ▁a ▁T IA ▁AP CO ▁standard ▁( USA ) ▁▁ ▁T ET R AP OL ▁( pre viously ▁M AT RA ) ▁ ▁* d PM R ▁ ▁References ▁ ▁External ▁links ▁▁ ▁Report ▁on ▁the ▁health ▁effects ▁of ▁T ET RA ▁by ▁NR P B ▁ ▁T ET RA ▁in ▁use ▁by ▁radio ▁am ateurs ▁T ET RA ▁and ▁Crit ical ▁Communic ations ▁Association ▁( T CC A ) ▁ ▁Radio communic ation ▁object ives ▁and ▁requirements ▁for ▁Public ▁Prote ction ▁and ▁Dis aster ▁Rel ief ▁( PP DR