Dynamic bandwidth allocation of both upstream and downstream in Orthogonal Frequency Division Multiplexing Passive Optical Network

Recently, more and more attention has been paid to the Orthogonal Frequency Division Multiplexing Passive Optical Network (OFDM-PON). And more importance has been attached to the algorithm achieving dynamic bandwidth allocation (DBA) by researchers. In this paper, an algorithm which aims at achieving multi-granularity DBA based on OFDM-PON is proposed. With the change of bandwidth needs, the number of subcarriers and their modulation formats can be adjusted adaptively. To efficiently utilize the bandwidth, the algorithm introduces a scheme from TDM-PON based on cyclic rotation and polling mechanism. An inner ONU queue is also proposed and multiple subcarrier channels are established in both upstream and downstream. Both simulation and analysis show that the bandwidth utilization of OFDM-PON is efficient.