What is Passive optical network?

A passive optical network (PON) is a fiber-optic telecommunications technology for delivering broadband network access to end-customers. Its architecture implements a point-to-multipoint topology, in which a single optical fiber serves multiple endpoints by using unpowered (passive) fiber optic splitters to divide the fiber bandwidth among multiple access points. Passive optical networks are often referred to as the "last mile" between an Internet service provider (ISP) and its customers.

Components and characteristics

A passive optical network consists of an optical line terminal (OLT) at the service provider's central office (hub) and a number of optical network units (ONUs) or optical network terminals (ONTs), near end users. A PON reduces the amount of fiber and central office equipment required compared with point-to-point architectures. A passive optical network is a form of fiber-optic access network.

In most cases, downstream signals are broadcast to all premises sharing multiple fibers. Encryption can prevent eavesdropping.

Upstream signals are combined using a multiple access protocol, usually time division multiple access (TDMA).