Patent ID: 6519255
Filing Date: 2003-02-11
Classification: H04J,H04L,H04Q

Abstract:
An optical network unit (ONU) connectable between an optical fiber and a plurality of twisted pairs, the optical fiber carrying data between a host digital terminal (HDT) and the ONU, the data consisting of broadband and narrowband data destined for the twisted pairs in a downstream direction and originating from the twisted pairs in an upstream direction, the ONU comprising:an optoelectronic transceiver connectable to the optical fiber, for receiving a downstream optical signal on the optical fiber and converting it into a downstream electronic signal for transmission to a downstream outstation, wherein the downstream electronic signal comprises frames sent by the HDT, each frame comprising a plurality of subframes, each subframe comprising a plurality of fields including an address field, a control field and a traffic field, each field comprising a respective plurality of traffic elements each having a header and a body, the address field of a subframe indicating a destination ONU for that subframe; a downstream outstation connected to the optoelectronic transceiver for receiving the downstream electronic signal from the optoelectronic transceiver and producing therefrom a downstream data stream, the downstream outstation including circuitry for reading the address field of each subframe in the downstream electronic signal and determining, for each subframe, whether the ONU in which the downstream outstation is located is the destination ONU as indicated in the address field of the subframe and, if so, transmitting the traffic elements in the traffic field of that subframe, thereby to produce the downstream data stream, a demultiplexer connected to the downstream outstation, for receiving the downstream data stream from the downstream outstation and controllably separating it into a plurality of downstream broadband data streams destined for respective ones of the twisted pairs and a plurality of downstream narrowband data streams also destined for respective ones of the plurality of twisted pairs; and for each twisted pair: a respective broadband processing unit connected to the demultiplexer comprising circuitry for receiving the respective downstream broadband data stream from the demultiplexer and converting it into a respective downstream broadband analog signal destined for said twisted pair; a respective narrowband processing unit connected to the demultiplexer comprising circuitry for receiving the respective downstream narrowband data stream from the demultiplexer and converting it into a respective downstream narrowband analog signal destined for said twisted pair; and a respective combiner connected to the respective broadband and narrowband processing units and connectable to the twisted pair, comprising circuitry for combining the respective downstream broadband analog signal and the respective downstream narrowband analog signal into a respective downstream composite analog data signal destined for said twisted pair.