Planning rules for split ratio selection in building GPON-based access networks

A dimensioning process of Gigabit Passive Optical Network (GPON) involves the selection of a split ratio that determines the allocated bandwidth per subscriber sharing a single passive optical network (PON) link (Optical Line Terminal (OLT) port). The selection of a small split ratio can be costly, whereas the selection of a higher split ratio can reduce the bandwidth allocated per subscriber and subsequently subscribers may quickly experience less quality in provisioned services. This paper aims to introduce planning rules and a mathematical model which can enable network planners, from day one, to optimally dimensioning GPON access network resources (PON link capacity, OLT´s ports, splitter´s ports). The mathematical model considers four parameters for optimal dimensioning GPON access network: Number of subscribers and their type, busy hour, service penetration rate and bandwidth requirement. The planning rules and mathematical model have been integrated into a software utility which we have developed to evaluate the support of next-generation services in GPON access network.