Patent ID: 8139950
Filing Date: 2012-03-20
Classification: H04Q

Abstract:
1. A passive optical network system, in which fixed-length frames, each of the fixed-length frames including a plurality of variable-length frames, are transmitted from master stations to slave stations, the passive optical network system comprising: a first master station for communicating at a first transmission rate; a second master station for communicating at a second transmission rate different from the first transmission rate; a first slave station for communicating with the first master station at the first transmission rate; a second slave station for communicating with the second master station at the second transmission rate; and an optical fiber network having a first splitter and a second splitter, variable-length frames from the first master station and the second master station being time-division multiplexed via the first splitter, and multiplexed variable-length frames being transmitted to the first and second slave stations via the second splitter, wherein the first master station and/or the second master station include: queues corresponding to previously determined priority, and for storing data to be transmitted to one of the first slave station and the second slave station, a queue sorting watching section for obtaining priority information of the queues of the own master station, and obtaining priority information of the queues from the other master station, an adjustment section for determining transmission timing of the variable-length frames transmitted from the first and second master stations based on the priority information of the queues of the own master station and the priority information of the queues of the other master station, which are obtained by the queue sorting watching section, and priority instruction information of the master stations previously defining which of the own master station and the other master station has priority, so that the variable-length frames from the first master station and the variable-length frames from the second master station do not collide with each other in the optical fiber network, and a transmission section for retrieving the data stored in the queues to form variable-length frames, and transmitting the variable-length frames to the first slave station and the second slave station via the optical fiber network according to the transmission timing determined by the adjustment section, wherein the first master station and the second master station transmit (i) transmission timing information indicating determined transmission timing of variable-length frames in a first fixed-length frame to be transmitted, (ii) at least a part of transmission timing information indicating determined transmission timing of variable-length frames in a second fixed-length frame to be transmitted next to the first fixed-length frame, and (iii) transmission rate information for the variable-length frames to be transmitted at each determined transmission timing, to the first slave station and/or the second slave station, by adding them into a header of a first variable-length frame which the first master station transmits first in the first fixed-length frame and a header of a second variable-length frame which the second master station transmits first in the first fixed-length frame respectively, and wherein the first slave station and/or the second slave station acquire(s), according to the transmission timing information and the transmission rate information, the variable-length frames at the transmission timing in which the variable-length frames with the first transmission rate or the second transmission rate of the own slave station are received, among the variable-length frames input from the optical fiber network.