Technology Used Primarily for Next Generation Network/FTTH:
The progress in the technology, the need for larger bandwidths and the complexity of ATM forced the FSAN group to look for better technology. Gigabit Passive Optical Network(GPON) standardization work was initiated by FSAN in the year 2001 for designing networks over 1Gbps. GPON architecture offers converged data and voice services at upto 2.5 Gbps. GPON enables transport of multiple services in their native format, specifically TDM and data. In order to enable easy transition from BPON to GPON, many functions of BPON are reused for GPON. In January 2003, the GPON standards were ratified by ITU-T and are known as ITU-T Recommendations G.984.1, G.984.2 and G.984.3. The GPON’s uses Generic Framing Procedure (GFP) protocol to provide support for both voice and data oriented services. A big advantage of GPON over other schemes is that interfaces to all the main services are provided and in GFP enabled networks packets belonging to different protocols can be transmitted in their native formats. EPON:
Ethernet equipment vendors formed Ethernet in the First Mile Alliance (EFMA) to work on a architecture for FTTH as Ethernet is a dominant protocol in Local Area Network. EPON based FTTH was adopted by IEEE standard IEEE802.3ah in September 2004. Adopting Ethernet technology in the access network would make uniform protocol at the customer end simplifying the network management. Single protocol in Local Area Network, Access Network and Backbone network enables easy roll out of FTTH. EPON standards networking community renamed the term ‘last mile’ to ‘first mile’ to symbolize its importance and significance access part of the network. EFM introduced the concept of Ethernet Passive Optical Networks (EPONs), in which a point to multipoint (P2MP) network topology is implemented with passive optical splitters. EPON, is largely vendor-driven standard and it is fundamentally similar to ATM-PON but transports Ethernet frames/packets instead of ATM cells. It specified minimum standardization and product differentiation, also it has decided not to standardize the Bandwidth allocation algorithm (DBA), TDM and ATM support, Security, Authentication, WDM Overlay Plan, support for Analog Video Protection, Diagnostics, Monitoring,, Compliance with existing OSS leaving these to the vendors to choose the best.