Patent ID: 7706416
Filing Date: 2010-04-27
Classification: H04J

Abstract:
1. An optical communication system for providing a broadcasting service and a data communication service to a plurality of subscribers, the optical communication system comprising: an OLT (Optical Line Terminal) for generating a digital downlink telephone voice data in response to analog telephone voice signals from the plurality of subscribers via a PSTN (Public Switched Telephone Network), for multiplexing the generated digital telephone voice data together with a broadcasting data and a communication data into a multiplexed downlink data, and for converting the multiplexed data into optical signals for a subsequent transmission to the plurality of subscribers, wherein the OLT being further configured for converting optical signals transferred upward into electric signals, demultiplexing and converting the uplink telephone voice data into analog telephone voice signals for a subsequent transmission to the PSTN; a plurality of ONTs (Optical Network Terminals) for converting the optical signals transferred from the OLT into electric signals, for demultiplexing the broadcasting data, the communication data, and the digital-converted downlink telephone voice data, and for converting the demultiplexed downlink telephone voice data into downlink analog signals for subsequent transmission to the plurality of subscribers, wherein the ONTs being further configured for generating digital uplink telephone voice data by converting the analog voice data from the plurality of subscribers into the digital telephone voice data, multiplexing the digital uplink telephone voice data together with the uplink communication data of the OLT for a subsequent transmission to the OLT; and an optical branching filter for branching the signals from the OLT to the plurality of ONTs, and combining and transferring the signals from the plurality of ONTs to the OLT; wherein the OLT comprises: a telephone switching system for receiving analog telephone voice data of the plurality of subscribers from a public switched telephone network (PSTN), separating the analog telephone voice data by subscribers, and transferring uplink analog voice data transferred from the ONTs to the PSTN; a plurality of first telephone data processing units, connected to the telephone switching system, for converting the transferred analog telephone voice data into digital telephone voice data in order to generate and transfer downlink telephone voice data, and converting the uplink telephone voice data into analog telephone voice data in order to generate and transfer the uplink analog voice data to the telephone switching system; a plurality of first broadcasting/communication/telephone multiplexers for multiplexing the downlink telephone voice data from the first telephone data processing unit together with broadcasting data for the broadcasting service and communication data for the data communication service; a plurality of first optical transmitters for performing an electrical/optical conversion of optically converting the multiplexed data output from the first broadcasting/communication/telephone multiplexer that is separately provided for each of the plurality of subscribers, into a optical signal with a different wavelength; a WDM multiplexer for multiplexing and outputting the optically converted signals from the first optical transmitter and outputting the multiplexed converted signals to the optical branching filter; a WDM demultiplexer for separating the optical signals from the ONT that are transmitted via the optical branching filter, based on a wavelength of the optical signals; a plurality of first optical receivers for receiving and converting the separated optical signals from the ONTs into electric signals, the first optical receiver being provided for each of the plurality of subscribers; and a telephone demultiplexer for demultiplexing the electric signals transferred from the first optical receiver, separating and transferring the uplink telephone voice data to the first telephone data processing unit, the telephone demultiplexer being provided for each of the plurality of subscribers; a broadcasting switch for switching and outputting MPEG (Motion Picture Experts Group) broadcasting data input by a plurality of broadcasting channels; a controller for supplying the broadcasting switch with a signal that is used to select a broadcasting channel based on a service user's demand; a first Ethernet switch for switching a direction of a communication/broadcasting/telephone multiplexer of communication data in order to determine which one among the uplink IP network or the ONT the communication data is transmitted to; and a second Ethernet switch for separating channel information data of a service user's preferred digital broadcasting from communication data of a service user and switching the channel information data and the communication data, wherein the telephone demultiplexer demultiplexes an electrical signal from the first optical receiver and supplies the second Ethernet switch with the demultiplexed electrical signals together with a signal for selecting a broadcasting channel and IP communication data: the second Ethernet switch supplies the controller with the input signal for selecting a broadcasting channel in order to control the broadcasting switch and supplies the first Ethernet switch with the input signal for selecting a broadcasting channel in order to transfer the input IP communication data to uplink IP network; the first telephone data processing unit divides a respective subscriber's analog telephone voice data outputted from the telephone switching system into analog voice data and signaling data, digitally converts the analog voice data and the signaling data, and transfers the converted digital telephone data to respective communication/broadcasting/telephone multiplexers provided for respective subscribers; the optical branching fitter comprises a first optical branching filter for branching signals from the OLT and transferring the branched signals to the plurality of ONTs and a second branching filter for combining signals from the plurality of ONTs and transferring the combined signals to the OLT.