Voice and digit compatible fully automatic radio paging system

A voice and digit compatible fully automatic radio paging system capable of transmitting both voice and digit code signals within a single paging call, said system comprising a central radio paging station and a plurality of pagers, wherein said central radio paging station comprises a telephone line interface through which the central radio paging station is connected to a telephone line, a voice and digit processing means connected with the output of the telephone line interface, and a transmitter connected with the voice and digit processing means, said voice and digit processing means including a central processor, a disc storage, a program memory, a voice and digit interface unit, a voice and digit encoding unit connected to a bus, and the input of said transmitter being connected with the voice and digit encoding unit;

• and said pagers include voice and digit compatible pagers capable of receiving voice and digit code signal, pure digit code signals and pure voice code signals, and capable of storing voice and digit information, pure digit pagers capable of receiving only pure digit code signal, and pure voice pagers capable of receiving only pure voice code signals;
• wherein the voice and digit interface unit is connected to said telephone line interface, for, under the control of the central processor, reading from said disc storage a voice prompt signal, sending the voice prompt signal to the telephone line, then receiving digital code and analog voice signals issued from a telephone, converting the received digital code to computer inner code, converting the received analog voice signal into a corresponding digitized signals and storing the converted code and digitized signals in the disc storage;
• said central processor hybridly encodes the converted code and digitized voice signals to produce a digital paging signal, to establish a paging information queue and storing the same in the disc storage;
• said voice and digit encoding unit converts the digital paging signal produced by the central processor into a radio paging code signal and transmits the radio paging code signal via the transmitter under the control of the central processor, and wherein the paging signal output from said voice and digit processing means is constituted by a prefix code T1, digital information frames T2 led by a frame synchronization code, and analog information frames T3 led by an idle code, the length of the analog information frames T3 being variable;
• the order of the paging signal is:
• T1, T2, - - - T3, - - - T1, the analog information frames being followed by another prefix code T1 indicating the end of the analog information frame;
• and the length of the analog frame T3 may be zero, the address code of said digital information frame T2 including functional bits indicating whether it is followed by analog information frame and the type of the paging information.