Here are options for communicating.
D000401:Aircraft; D004189:Disaster Planning; D004631:Emergency Medical Service Communication Systems / Q000592:standards*; D006747:Hospital Communication Systems / Q000592:standards*; D006801:Humans; D008402:Mass Media; D009519:New York City; D011641:Public Relations; D013685:Telecommunications / Q000295:instrumentation*; D023481:Terrorism; D014481:United States; D014768:Virginia