A Passive Optical Network (PON1) is an access technology based on the specification developed by the Full Service Access Network (FSAN) vendor consortium. The ITU-T subsequently ratified PONs in the G.983.1 Recommendation.

Passive is the key word here: PON uses small, inexpensive optical splitters, rather than the relatively large, expensive, and power-hungry optical repeaters used in more traditional optical networks.