XGS-PON, the 10 Gbps symmetric successor to both GPON and EPON, is now the architecture of choice for new FTTH deployments across North America. The FBA FiberConnect community has tracked this shift across multiple deployment cycles, and the economics that once favored GPON in large-scale builds have changed materially in the last 18 months.
Where GPON and EPON Still Appear
GPON (Gigabit Passive Optical Network) and EPON (Ethernet Passive Optical Network) remain in service across millions of existing subscribers. GPON dominated large telco builds in the 2010s due to lower OLT port costs and mature vendor ecosystems. EPON, with its Ethernet-native architecture, found stronger adoption among cable operators and enterprise network builders who prioritized integration simplicity.
Neither technology is being replaced in existing infrastructure. The economic question is which architecture to specify for new builds and overbuild projects starting today.
The XGS-PON Case
XGS-PON delivers 10 Gbps symmetric to the subscriber on the same G.652.D fiber plant as GPON or EPON. The outdoor infrastructure, the fiber itself, does not change. What changes is the OLT hardware in the headend and the ONT at the subscriber premises.
OLT port costs for XGS-PON have declined significantly since 2023 as vendor competition has increased and component volumes have scaled. For new builds, the incremental cost of specifying XGS-PON over GPON is now small relative to the total project cost, while the capacity headroom is substantial. A subscriber on XGS-PON today will not require a field truck roll for a service upgrade for the foreseeable future [FBA, Fiber Broadband Scalability and Longevity, 2024].
What This Means for Network Architecture Decisions
For ISPs evaluating a new build or overbuild, specifying GPON in 2026 means locking in a technology ceiling that most residential subscribers will hit within a single contract renewal cycle. The OLT upgrade path from GPON to XGS-PON is straightforward technically, but it requires a planned headend visit and creates a customer-facing service window.
Specifying XGS-PON from the start eliminates that upgrade cycle and positions the network for multi-gigabit residential tiers without additional outside plant work.
The economics of XGS-PON have reached the point where the case for deploying legacy PON architecture in new construction requires specific justification. That justification should appear in your cost model before it appears in your design.