PON Split Ratios and Splitter Loss
| Split Ratio |
Theoretical (dB) |
Real-World (dB) |
| 1:2 |
-3 |
-3.7 |
| 1:4 |
-6 |
-7.2 |
| 1:8 |
-9 |
-10.7 |
| 1:16 |
-12 |
-14.1 |
| 1:32 |
-15 |
-17.4 |
| 1:64 |
-18 |
-20.8 |
| 1:128 |
-21 |
-24.2 |
Single-Mode Fiber Loss by Distance
| Distance |
Loss @ 1310 nm |
Loss @ 1550 nm |
| 1 km |
-0.35 dB |
-0.20 dB |
| 2 km |
-0.70 dB |
-0.40 dB |
| 3 km |
-1.05 dB |
-0.60 dB |
| 5 km |
-1.75 dB |
-1.00 dB |
| 10 km |
-3.50 dB |
-2.00 dB |
| 15 km |
-5.25 dB |
-3.00 dB |
| 20 km |
-7.00 dB |
-4.00 dB |
| 50 km |
-17.50 dB |
-10.00 dB |
| 100 km |
-35.00 dB |
-20.00 dB |
PON and BiDi Wavelengths
GPON and XGS-PON
| Technology |
Downstream (OLT → ONU) |
Upstream (ONU → OLT) |
Standard |
| GPON |
1490 nm |
1310 nm |
ITU-T G.984 |
| XGS-PON |
1577 nm |
1270 nm |
ITU-T G.9807.1 |
| EPON |
1490 nm |
1310 nm |
IEEE 802.3ah |
| 10G-EPON |
1577 nm |
1270 nm |
IEEE 802.3av |
Common BiDi SFP Wavelength Pairs
| Pair Type |
Side A TX |
Side A RX |
| 1310/1490 |
1310 nm |
1490 nm |
| 1310/1550 |
1310 nm |
1550 nm |
| 1270/1330 |
1270 nm |
1330 nm |
| 1490/1550 |
1490 nm |
1550 nm |
PON Link Budget Classes
GPON (ITU-T G.984.2)
| Class |
Min Loss (dB) |
Max Loss (dB) |
OLT TX (dBm) |
| A |
5 |
20 |
+2 to +7 |
| B |
10 |
25 |
+2 to +7 |
| B+ |
13.5 |
28 |
+1.5 to +5 |
| C |
15 |
30 |
+3 to +7 |
| C+ |
17 |
32 |
+3 to +7 |
XGS-PON (ITU-T G.9807.1)
| Class |
Min Loss (dB) |
Max Loss (dB) |
OLT TX (dBm) |
| N1 |
14 |
29 |
+2 to +6 |
| N2 |
16 |
31 |
+4 to +8 |
| E1 |
18 |
33 |
+6 to +9 |
| E2 |
20 |
35 |
+8 to +11 |
Fiber Color Codes
| Fiber Number |
Color |
| 1 |
Blue |
| 2 |
Orange |
| 3 |
Green |
| 4 |
Brown |
| 5 |
Slate |
| 6 |
White |
| 7 |
Red |
| 8 |
Black |
| 9 |
Yellow |
| 10 |
Violet |
| 11 |
Rose |
| 12 |
Aqua |