OPTICAL SUBSCRIBER DEVICE AND FRAME TRANSMISSION AMOUNT SPECIFYING METHOD

PROBLEM TO BE SOLVED: To specify a transmission request amount of which an optical line terminal is to be notified, from a frame length of each frame accumulated in a plurality of queues without increasing a circuit scale of a cumulative data amount search unit and a memory size of a cumulative data amount table.SOLUTION: An optical subscriber device includes a transmission request amount search unit 18 that, on the basis of a queue length that serves as a total data amount of each frame in a queue, calculated from a cumulative data amount in a cumulative data amount table corresponding to the queue, selects a queue in which a cumulative queue length obtained by accumulating the queue length from the highest priority queue becomes a minimum equal to or more than a data amount threshold, as a search object queue, searches the cumulative data amount table corresponding to the search object queue to search for a frame segment of a frame in which a total data amount becomes a maximum equal to or less than the data amount threshold, and thereby specifies the total data amount to the end of the frame segment as a transmission request amount.