COMMUNICATION DEVICE AND BANDWIDTH ALLOCATION METHOD

To obtain a communication device that provides a bandwidth allocation opportunity to an ONU having a plurality of data transmission rates, not depending on any specific bandwidth-request notifying method, thereby realizing fair upstream transmission data delay between data transmission rates of respective ONUs. The communication device includes a bandwidth-update-cycle division processor 13 that calculates a required bandwidth request amount ratio for each of the data transmission rates based on a communication quality set for each of slave station devices 20-1 to 20-n and divides the bandwidth update cycle into slots of each of the data transmission rates by using the ratio, a bandwidth-allocation-amount calculating unit 14 that allocates a bandwidth to the slave station devices 20-1 to 20-n having a corresponding data transmission rate in a slot of the data transmission rate, and a transmission-start-time calculating unit 15 that sets a transmission start time and a transmission time of data of the slave station devices 20-1 to 20-n, based on an overhead length of a data frame transmitted by the slave station devices 20-1 to 20-n.