PASSIVE OPTICAL SUBSCRIBER NETWORK TO WHICH CODE DIVISION MULTIPLEX ACCESS METHOD IS APPLIED

PROBLEM TO BE SOLVED: To provide a passive optical subscriber network not using a complex MAC (Media Access Control) by using wavelength-division multiplexing for a downward transmission and using code division multiplex access method for an upward transmission. SOLUTION: The passive optical subscriber network is provided with ONTs 101-116, WDM filters 20, 26 which separates between the upward wavelength and the downward wavelength, OLTs 301-30N which transfer upward signal to a higher network and transmit a transfer signal from the higher network as a downward signal to the ONT, and an optical coupler 200 which combines the upward signals. Each ONT is provided with a switching section 10 for a lower interface, a level converter 12 which converts an ethernet (R) signal into -1, +1 levels, a code generator 24 which generates an unique CDMA code for each ONT, a multiplier 14 which performs spectrum spread, and optical modulators 16, 18 which perform optical modulation. In addition, an OLT is provided with an optic receiver 28 which photo-converts the upward signal, a demultiplexer 29 which demultiplexes the signal, a code generator 34 which generates the CDMA code, a multiplier 32 which performs back spread, and a data discriminator 36 which extracts data through correlated calculation. COPYRIGHT: (C)2005,JPO&NCIPI