Patent ID: 6269106
Filing Date: 2001-07-31
Classification: H04J,H04N

Abstract:
A method for use in a communication access network, said communication access network including a plurality of terminals (T12, T12, T13, . . . , T31, . . . ) and a head-end (HE) which includes a plurality of transceivers (TRX1, TRX2, TRX3, . . . ), said head-end (HE) being downstream coupled to each one of said plurality of terminals (T12, T12, T13, . . . , T31, . . . ) via a downstream common link (Lc) and a tree-like distributive network, each one of said plurality of transceivers (TRX1, TRX2, TRX3, . . . ) providing one of a plurality of downstream signals (Sd1, Sd2, Sd3, . . . ), in one of a plurality of frequency bands (CH1, CH2, CH3, . . . ) associated to said one of said plurality of transceivers (TRX1, TRX2, TRX3, . . . ) to a combiner (COMB) included in said head-end (HE), said plurality of downstream signals (Sd1, Sd2, Sd3, . . . ) being together combined by said combiner (COMB) into a downstream modulated signal (S-MOD), said downstream modulated signal (S-MOD) being broadcasted from said head-end (HE) to said plurality of terminals (T12, T12, T13, . . . , T31, . . . ), a first one (T12) of said plurality of terminals being upstream coupled to a first one (TRX1) of said plurality of transceivers via an upstream link, said method being to provide information to said first terminal (T12) concerning a filter frequency band (CH1) being a first one of said plurality of frequency bands (CH1, CH2, CH3, . . . ) and to be used by said first terminal (T12) to filter out of said downstream modulated signal (S-MOD) a first regenerated downstream signal associated to a first one (Sd1) of said downstream signals provided by said first transceiver (TRX1), and characterized in that said method includes the steps of:a) inserting at least one pilot tone signal (P1i, P1j, P1k) in said downstream modulated signal (S-MOD), each pilot tone signal (P1i) of said at least one pilot tone signal (P1i, P1j, P1k) being inserted in a predefined pilot tone frequency band (CHp1i) of at least one pilot tone frequency band (CHp1i, CHp1j, CHp1k), said at least one pilot tone signal (P1i, P1j, P1k) including said information concerning said first frequency band (CH1); andb) filtering out of said downstream modulated signal (S-MOD) by said terminal (T12) with a derived frequency band (CHd1i, CHd1j, CHd1k) said at least one pilot tone signal (P1i, P1j, P1k), said derived frequency band (CHd1i, CHd1j, CHd1k) being derived from said at least one predefined pilot tone frequency band (CHp1i, CHp1j, CHp1k).