Prediction-based SQ-DRR scheme for QoS guaranteeing in E-PON systems

Abstract

Ethernet passive optical network (EPON) technology is being considered as a promising solution for next-generation broadband access network due to the convergence of low-cost Ethernet equipment and tow-cost fiber infrastructure. A major feature fur this new architecture is the use of a shared transmission media between all users. Medium access control arbitration mechanisms are essential for the successful implementation of EPON. This architecture uses the time-division multiplexing (TDM) approach to deliver data encapsulated in Ethernet packets from a collection of Optical Network Units (ONUs) to a central Optical Line Terminal (OLT) over the PON access network. The OLT, in turn, is connected to the rest of the Internet. In order to assign time slot to each ONU, a network management protocol has been devised - Multi-Point Control Protocol (MPCP). ONU can report its required bandwidth to OLT and then OLT grants bandwidth to ONU using MPCP messages. EPON also offer great flexibility in dynamic bandwidth allocation with MPCP messages. The main and most important feature of EPON is that it must support all existing services as well as of for new required service. In order to efficiently answer the various requirements for the multi-user and multi-services network, EPON must support quality of service (QoS) as part of their bandwidth allocation and scheduling schemes. This thesis proposes a new scheduling algorithm for EPON, prediction-based SQ-DRR(Short-term QoS Deficit Round Robin) scheme for QoS guaranteeing. The core of this algorithm is the combination of SQ-DRR and traffic prediction. SQ-DRR provides a method to guarantee QoS requirements and traffic prediction makes ONU get more bandwidth than the bandwidth which ONU requested.