decis execut committe april schengen acqui relat telecommun sch execut committe regard articl convent implement schengen agreement regard articl abovement convent decid tactic oper requir futur cross border digit radio system polic custom servic schengen state defin accord mandat pursuant articl rule manufactur administ uniform encrypt algorithm agreement establish remit subgroup telecommun set document approv sch telecom rev june quot definit telecommun equip polic custom servic quot sch telecom june quot digit radiocommun system secur organis tactic oper requir quot sch telecom rev novemb quot requir termin user interfac schengen state futur digit trunk radio system quot sch telecom rev decemb quot request etsi studi european norm meet schengen function requir quot sch telecom novemb quot schengen commun requir tetra standard quot sch telecom crypto rev juli quot digit radio commun network secur organis secur requir quot sch telecom crypto rev februari quot agreement custodi schengen algorithm quot sch telecom crypto rev februari quot criteria manufactur schengen specif algorithm quot sch rev quot amend mandat subgroup telecommun examin interoper aspect digit radio commun system quot luxembourg april chairman schapper restrict document