NFS: A new DBA to alleviate channel idle time in heterogeneous WDM-EPONs

Several dynamic bandwidth allocation (DBA) protocols have been introduced to utilize upstream channel in Ethernet Passive Optical Networks (EPONs). In this paper, a novel MAC protocol, called Nearest First Scheme (NFS) is introduced. NFS can minimize end to end delay and packet drop ratio at ONUs. Additionally, NFS can relive the common drawback of offline scheduling, i.e., channel idle time. NFS schedules ONU by taking RTT's dissimilarities into account and improves network performances.