Planning 10G PON migration strategies JU LY/ A UG 201 2 5 ® DAVID RUSSELL is solutions marketing director at Calix . By DAVID RUSSELL The right strategy depends significantly on whether you expect to use 10G EPON or GPON. C OMMERCIAL deployments of 10- Gbps passive optical networks ( 10G PONs) are just in their infancy. But all service providers need to plan now how they will deploy these new technologies on top of their existing networks. Luckily, the working groups that created these standards, the ITU ( FSAN) and IEEE, took into account carriers’ network migration concerns. A few simple planning steps today should eliminate a lot of headaches down the road when service providers are ready for 10G PONs. 10G PON standards To understand the 10G PON migration strategies, it is helpful to have a basic understanding of the 10G PON standards. 10G EPON. The first completed 10G standard was IEEE 10G EPON ( 802.3av) in September 2009. The vendor community has completed technology development based on this standard, and products are now commercially available. IEEE 10G EPON supports both 10G downstream/ 10G upstream as well as a 10G downstream/ 1G upstream formats. In both cases, the downstream transmission uses a 1577- nm wavelength. In the upstream, the 10G version uses 1270 nm and the 1G uses 1310 nm ( from 1260 nm to 1360 nm). 10G GPON ( G. 987). The ITU ratified the 10G GPON standard, officially known as XG- PON (“ X” being Roman numeral 10), in June 2010. There are as yet no known commercial deployments. The IEEE and the ITU coordinated on their wavelength selection, so XG- PON uses 1577 nm in the downstream and 1270 nm for the upstream. Figure 1 diagrams the 10G EPON and GPON standards. FSAN, which acts as a working group for the ITU on PON standards, continued to work on a standard beyond XG- PON. This standard is referred to as NG- PON2. A variety of technologies have been