How is EPON OSP different from a GPON OSP in terms of planning. what additional considerations must be kept in mind?

Ok ... There are also many differences between EPON and GPON. EPON, based on Ethernet technology, is compliant with the IEEE802.3ah Ethernet in the First Mile standard that is now merged into the IEEE Standard802.3-2005. It is a solution for the "first mile" optical access network. GPON, on the other hand, is an important approach to enable full service access network. Its requirements were set force by the Full Service Access Network (FASN) group, which was later adopted by ITU-T as the G.984.x standards–an addition to ITU-T recommendation, G.983, which details broadband PON (BPON).