Wavelength Division Multiplexing Three-Rate Combo PON
Combo PON integrates a WDM1r multiplexer within a single SFP+ optical module, combining four wavelengths—GPON (1490/1310nm), XG-PON (1490/1310nm), and XGS-PON (1577/1270nm)—into a single path for transmission over a single fiber. When three types of ONUs are connected simultaneously to a single Combo PON port, the total downlink bandwidth reaches 12.5Gbps (10G + 2.5G), and the total uplink bandwidth reaches 11.25Gbps (10G + 1.25G). The OLT automatically identifies the type of ONU connected and allocates the corresponding channel.
Comparison of selection risks for three mainstream technology standards
| Evaluation Dimension | XG-PON | XGS-PON | Combo PON Solution |
|---|---|---|---|
| ODN Reconstruction | Requires adjusting optical fibers or adding external WDM devices, with complex engineering | Requires adjusting optical fibers or adding external WDM devices, with complex engineering | No need to adjust ODN, directly replace the original GPON card to complete the upgrade |
| Optical Power Budget | External WDM introduces 1~1.5dB insertion loss, leading to tight power budget | External WDM introduces 1~1.5dB insertion loss, leading to tight power budget | No additional insertion loss, maintaining the original optical power budget |
| Equipment Room Space | Requires additional equipment or occupies more rack slots | Requires additional equipment or occupies more rack slots | Single-board single-port design, consistent with GPON card physical form, no extra space occupation |
| Operation & Maintenance Management | Multiple sets of equipment managed separately with high complexity | Multiple sets of equipment managed separately with high complexity | Unified network management, automatic channel adaptation, inheriting the original MIB library |
| Investment Protection | Requires phased replacement of existing GPON ONUs | Compatible with XG-PON, but requires replacement of existing GPON ONUs | Existing GPON ONUs can continue to be used, only need to upgrade the line side |
Common cofigulation examples:
Huawei MA5800 OLT with CGHF/CGUF 16 port card
ZTE C600 OLT with GFCH XGS-PON&GPON Combo
