Distributed DBA Scheme for Fog Node Equipped LR-EPON Based FiWi Network

To cater a large number of wireless and wireline users distributed over a large area, long-reach Ethernet passive optical network (LR-EPON) can be used as the mobile backhaul for fiber-wireless (FiWi) networks. In LR-EPON based FiWi network, a wireless base station (BS) is connected to an optical network unit (ONU). The centralized dynamic bandwidth allocation (DBA) schemes used for upstream traffic transmission in conventional EPON cannot be efficiently utilized in LR-EPON due to inefficient bandwidth utilization caused by increased round-trip time (RTT) between OLT and ONU. We propose a distributed DBA scheme for LR-EPON based FiWi network whereby the bandwidth allocation decision is taken by the ONUs themselves instead of OLT to mitigate the dependency on large RTT. Through simulation study, we show that our proposed distributed DBA scheme performs better than the centralized and other existing distributed DBA schemes in terms of the average delay and average queue occupancy. Using our proposed distributed DBA scheme, we also explore three architectures for the placement of fog node at different locations in LR-EPON based FiWi network. We show performance of the different architectures along with using our proposed distributed DBA scheme for different offered traffic load conditions.