METHOD OF TRANSMISSION OF MESSAGES FOR CENTRALIZED SECURITY SYSTEMS OF VEHICLES AND IMMOVABLE PROPERTY Russian patent published in 2004 - IPC

FIELD: security systems. SUBSTANCE: in case of violation of protection of object under protection serial binary code message is transmitted to centralized security station with number of M control bits at constant duration T_BIT of symbols. Depending on adopted code, light and sound signals are generated and/or warning is transmitted by communication line. At transmission of first symbol for instance "I'm random or pseudorandom frequency F_R is used at beginning of transmission of message, and at transmission of second symbol, for instance, "O", frequency F_R+ΔF, is used where ΔF is fixed internal. At centralized security station, sections of channels are selected being spaced integer number K less than internal ΔF. In each channels, P additive functions of message are determined within T_BIT duration at uniform displacement of moment of finishing of determination of each additive function per interval T_BIT/P. Additive functions coinciding with moments of finishing of their determination are compared and it is conventionally set that first of symbols is adapted in those channels for which value of additive functions exceeds value of additive functions of channels whose number is greater by K, and second symbol, in the rest of channels. Comparison with tolerable for reception message codes is effected for sequences of conventionally set symbols in each channel and for each moment of finishing of determination of additive functions at total number of symbols in sequence equal to M. EFFECT: increased cover range and interference protection of centralized security system. 6 cl, 4 dwg