Analysis of FiWi networks to improve TCP Performance

Hybrid Fiber-Wireless access networks aim at combining optical subnetwork and wireless subnetwork with the objective to reduce their complexity and cost. In wireless subnetwork multipath routing is applied in order to improve throughput. Because of different delays along multiple paths, packets may arrive out of order, which may cause TCP Performance degradation. As all traffic in a FiWi network is sent to the OLT, the OLT serves as a convergence node which naturally makes it possible to re-sequence packets at the OLT before they are sent to the internet. To overcome this problem, Scheduling Algorithms (FIFO, DRR, and Modified Deficit Round Robin) at Optical Line Terminal (OLT) is used effectively to reduce Packet Reordering and to improve TCP Performance. Simulation results show that the MDRR scheduling algorithm provides scalable solution to mitigate the side-effect of packet reordering caused by multi-path routing.