Patent ID: 7457542
Filing Date: 2008-11-25
Classification: H04B,H04J,H04L

Abstract:
1. An optical access network system where a central office side apparatus and a plurality of subscriber connection apparatuses connected to subscriber terminals are connected through a Passive Optical Network (PON), each subscriber connection apparatus transmitting data during a transmission grant period assigned from said central office side apparatus, said central office side apparatus comprising: a main controller to notify each subscriber connection apparatus of a transmission grant period; an equalizer of a tap gain adaptive control type to correct waveform distortions of signals received from the subscriber connection apparatuses; an equalizer controller for setting initial values of tap gains to said equalizer; and a parameter table for storing the initial values of the tap gains to be set to said equalizer, in association with identifiers of said subscriber connection apparatuses; wherein said main controller issues a switchover request for switching an equalization characteristic to said equalizer controller, designating the identifier of a subscriber connection apparatus each time notifying the subscriber connection apparatus of a transmission grant period, and said equalizer controller retrieves, in response to said switchover request, the initial values of the tap gains corresponding to the designated identifier from said parameter table and sets the initial values of the tap gains to said equalizer.