Patent ID: 7773880
Filing Date: 2010-08-10
Classification: H04J

Abstract:
1. An optical access system, comprising: an optical network terminal connected to a user terminal, an optical line terminal connected to the optical network terminal and a network, wherein the optical access system transmits to the network time-division multiplexed signals sent from the user terminal via the optical network terminal and the optical line terminal using cyclic frames, the optical access system performs a ranging during a ranging time period for measuring a distance between the optical line terminal and the optical network terminal, when the optical network terminal transmits the time-division multiplexed signals received from the user terminal to the network via the optical line terminal using the cyclic frames, the optical network terminal stores signals of the time-division multiplexed signals that would be transmitted to the optical line terminal using the cyclic frames during time cycles of a storing time period that includes the ranging time period and that is either equal to or longer than the ranging time period, and transmits the signals of the time-division multiplexed signals that would be transmitted to the optical line terminal using the cyclic frames during the time cycles of the storing time period during a time cycle that is subsequent to the storing time period, and when the optical line terminal transmits the time-division multiplexed signals received from the optical network terminal to the network, the optical line terminal transmits the time-division multiplexed signals in a continuous periodic manner using the cyclic frames by temporally storing the signals of the time-division multiplexed signals which are transmitted from the optical network terminal during the time cycle that is subsequent to the storing time period, sequentially transmitting the signals of the time-division multiplexed signals that are transmitted from the optical network terminal during the time cycle that is subsequent to the storing time period, and, during the ranging, transmitting to the network to be signals of the time-division multiplexed signals which were transmitted from the optical network terminal before the storing time period.