Throughput and Framing Efficiency
GPON provides 2.488 Gbps downstream and 1.244 Gbps upstream using proprietary GEM (GPON Encapsulation Method) framing, achieving an impressive 92% bandwidth efficiency.
In contrast, EPON provides a symmetrical 1.25 Gbps downstream and upstream using standard Ethernet frames with 8b/10b line coding, yielding roughly 72% payload efficiency.
| Parameter | GPON (ITU-T G.984) | EPON (IEEE 802.3ah) |
|---|---|---|
| Downstream Speed | 2.488 Gbps | 1.25 Gbps |
| Upstream Speed | 1.244 Gbps | 1.25 Gbps |
| Max Split Ratio | 1:64 or 1:128 | 1:32 or 1:64 |
| Downstream Wavelength | 1490 nm | 1490 nm |
| Upstream Wavelength | 1310 nm | 1310 nm |
| Video Overlay | 1550 nm (RF CATV) | 1550 nm (RF CATV) |
| Framing Efficiency | 92% | 72% |
Splitter Budgeting in CoreMap
Because GPON offers higher optical power classes (Class B+ with 28 dB budget, Class C+ with 32 dB budget), operators can comfortably cascade 1:64 splits across multiple junction boxes.
CoreMap's Signal Engine dynamically flags when a 1:128 split in GPON pushes customer optical power below -25 dBm, preventing technician over-splitting.