This paper describes a new ring-based Passive Optical Network（PON）technology which has the advantage of supporting physical layer LAN emulation and enhancing ability of Private Network due to some of the limitations of traditional PON technology supporting private networking.Many aspects have been discussed in detail such as the architecture

mechanism

key technologies and related verification experiment for ring-based TDM-PON

WDM-PON and Hybrid PON（H-PON）.In final the establishment of VPN virtual ring link by using hybrid PON（WDM/OFDM-PON）technology to solve the VPN emulation transport among intra PONs and inter PONs without change of traditional PON physical layer topology has been discussed.The ring-based PON technology is well suitable for the access network which needs the requirements of high reliability and high security.