Classical Mode A - 8 us P1 P2 P3 (P2 is sent on omni channel)
Classical Mode C - 21 us P1 P2 P3 (P2 is sent on omni channel)
Mode A + short P4 - Makes classicals reply but adds in P4 - Classical tranpsonders ignore P4 (P2 is sent on sum or beam channel)
Mode C + short P4 - Makes classicals reply but adds in P4 - Classical tranpsonders ignore P4 (P2 is sent on sum or beam channel)
Mode S ALL CALL - P1 P2 P6 (short 56 bits DPSK) UF11 (P2 is sent on sum or beam channel)
Mode S ROLL CALL - P1 P2 P6 (short 56 bits or long 112 bits DPSK) UF4 or UF5 (Altitude or Identity) (P2 is sent on sum or beam channel)