Passive optical network(PON)

as the major technology solution of the access network

provides higher bandwidth utilization efficiency

supports for farther transmission distance and has the stronger anti-interference capability than the traditional access network technology.According to the development of PONs

this paper firstly summarizes the background and features

sorts out relationship and main standards.Secondly

the frame structures of various PONs are introduced and a noble table containing the main parameters of PONs is presented.Based on the current hot spots of researches at home and abroad

the overview is focused on the media access control protocols

frame structures

dynamic bandwidth allocation algorithms

energy saving

and so on.Finally

we show the idea about the future development trends of PONs.