XGS-PON is the symmetric 10 Gbps PON defined by ITU-T G.9807.1 — both downstream and upstream run at 9.953 Gbps. That symmetry is the whole point: where GPON's 1.244 Gbps upstream gets shared and saturated by dozens of subscribers doing cloud backups and surveillance backhaul, XGS-PON lifts upstream to the same 9.953 Gbps as downstream, which is why it wins in high-upload scenarios like enterprise cloud, video backhaul, and 5G fronthaul.
XGS-PON is symmetric 10 Gbps (9.953 Gbps each way); GPON is 2.488 down / 1.244 up and chokes on upstream.
It coexists with GPON on the same fiber and ODN via Combo PON (WDM at 1577/1270 nm vs 1490/1310 nm), so you upgrade without touching splitters or outdoor fiber.
One PON port supports up to 1:256 split at ~20 km, roughly doubling the subscribers per OLT versus GPON's 1:128.
GPON's real bottleneck is the upstream. When users stream 4K, push surveillance footage, or run backups, that 1.244 Gbps upstream is carved among many households. XGS-PON pulls upstream up to 9.953 Gbps, so even a crowded PON port never collapses under upload contention. At the standard level, XGS-PON and XG-PON (G.987) share the same OS2/OM4 fiber and ODN — the only difference is symmetry: XG-PON is asymmetric 10 Gbps down / 2.5 Gbps up, while XGS-PON is symmetric 10/10.
| Standard | Downstream | Upstream | Wavelength (down/up) | Split ratio |
|---|---|---|---|---|
| GPON (G.984) | 2.488 Gbps | 1.244 Gbps | 1490 / 1310 nm | 1:128 |
| XG-PON (G.987) | 10 Gbps | 2.5 Gbps | 1577 / 1270 nm | 1:256 |
| XGS-PON (G.9807.1) | 9.953 Gbps | 9.953 Gbps | 1577 / 1270 nm | 1:256 |
Note: Both XG-PON and XGS-PON use 1577 nm downstream / 1270 nm upstream — distinct from GPON's 1490 / 1310 nm — which is what lets WDM multiplex them on one fiber.
XGS-PON runs 1577 nm down / 1270 nm up, offset from GPON's 1490 / 1310 nm. Through WDM, XGS-PON and GPON coexist on the same fiber and the same ODN — that is the Combo PON idea: one OLT line card emits both wavelengths, legacy ONUs stay on GPON, new ONUs move to XGS-PON, and you never touch the splitters or outdoor fiber. For an operator already running GPON, this is the smooth upgrade path.
Rayin's GPON product line is already live at the edge FTTH, typified by the GPON OLT L102P: 2 GPON ports, 1:128 split per port, 2×GE + 1×SFP+ 10GE uplink, compliant with ITU-T G.984 and interoperable with mainstream ONUs. The XGS-PON OLT sits in Rayin's roadmap; once it lands, symmetric 10G edge access gets simpler. To judge 10G readiness today, walk through the four steps below.
Step 1 — Is upstream the bottleneck? If users do 4K cloud sync, surveillance回传, and enterprise backups, and the 1.244 Gbps upstream stays full, stop deliberating — symmetric 10G XGS-PON solves it directly where GPON cannot.
Step 2 — Can the ODN be reused? If you already have GPON splitters and fiber, prefer Combo PON (same-fiber coexistence) and add the XGS-PON wavelength without re-cabling outdoors. A greenfield deployment can be designed for XGS-PON from day one.
Step 3 — Check split ratio and optical budget. Target 1:256 or beyond 20 km, and verify Class N1/N2 transmit and receive sensitivity. If the budget is short, reduce the split ratio or add an optical amplifier — do not force it.
Step 4 — Confirm ONU interoperability. The XGS-PON OLT must interoperate with the ONUs you will deploy; confirm both honor ITU-T G.9807.1 on OS2/OM4 and the wavelength plan to avoid vendor lock-in.
Can XGS-PON and GPON share the same fiber? Yes. XGS-PON uses 1577 / 1270 nm and GPON uses 1490 / 1310 nm; WDM lets both coexist on one fiber (Combo PON). Legacy ONUs stay on GPON while new ONUs move to 10G, with no change to splitters or outdoor cable.
Why does symmetric upstream matter so much? Surveillance backhaul, enterprise cloud backup, and 5G fronthaul are upload-heavy. GPON's 1.244 Gbps upstream is shared by many users and saturates first; XGS-PON's symmetric 9.953 Gbps upstream removes that contention on a crowded PON port.
What split ratio does XGS-PON support? A single XGS-PON port supports up to 1:256 splitting at a typical 20 km reach. That is double GPON's 1:128, so one OLT serves roughly twice the subscribers and lowers cost per home — at the price of a tighter optical power budget.
Is XGS-PON compatible with my existing ODN? In most cases yes. XGS-PON reuses the same OS2/OM4 fiber and ODN as GPON and XG-PON; via Combo PON you add the XGS-PON wavelength on the existing plant. Just confirm Class N1/N2 optical budget for long reach or high split ratios.
What is Combo PON? Combo PON is a single OLT line card that emits both GPON (1490/1310 nm) and XGS-PON (1577/1270 nm) wavelengths on one fiber through WDM. Legacy ONUs keep running on GPON while new ONUs are cut over to 10G, enabling a non-disruptive upgrade.
XGS-PON is the symmetric 10G step up from GPON, and Combo PON is what makes the migration painless. If upstream is your bottleneck and your ODN can be reused, the case for XGS-PON is straightforward.
About the author: Sara — Sara is a Customer Manager at Rayin with over 10 years of experience in the communications field. In her free time, she enjoys badminton and swimming.
About Rayin: Shenzhen Rayin Technology Co., Ltd. — Company Profile
