How to Resolve Incompatibility Between GPON and XG-PON ONTs When They Share the Same ODN

Tx and Rx wavelengths

Type Downstream Direction Upstream Direction
GPON Center wavelength: 1490 nm
Wavelength range: 1480-1500 nm
Center wavelength: 1310 nm
Wavelength range: 1290-1330 nm
XG-PON Center wavelength: 1577 nm
Wavelength range: 1575-1580 nm
Center wavelength: 1270 nm
Wavelength range: 1260-1280 nm

From wavelengths of XG-PON (asymmetric system with upstream rate 2.5 Gbit/s and downstream rate 10 Gbit/s) and GPON ONTs, if they share the same ODN, GPON ONTs (Table 51-2 lists compatibility) in the earlier stage require wavelength block filter (WBF) for downstream isolation because they are in poor performance in downstream optical signal isolation from XG-PON ONTs. Otherwise, packet loss or even disconnection may occur caused by signal interference. Therefore, the WBF needs to be added on the ONT or optical splitter.
Solution
The WBF is added on the optical splitter for GPON ONTs that are incompatible with XG-PON ONTs sharing the same ODN. Specifically,

  • Male and female connectors.
  • Can be externally connected to the SC/UPC (Shown in the following figure) or AC/APC connector.

SC/UPC connector
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Figure 51-2 and Figure 51-3 show specific solutions for live networks.
Figure 51-2 ONTs of different types are connected to the same optical splitter
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Figure 51-3 Only early-stage GPON ONTs are connected to the same optical splitter
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Table 51-2 lists compatibility between GPON ONTs and XG-PON ONTs.

  • The time in Compatibilityis calculated from the ONT replacement. Detailed markets and BOM codes needed to be queried.
  • For details, collect the ONT SN and provide it to the Huawei technical support engineer for querying.

Table 51-2 Compatibility between GPON ONTs and XG-PON ONTs

Model Compatibility
HG810/HG810A/HG850 Supported from the delivery in June 2012.
HG865/HG866 Supported from the delivery in January 2011.
HG851/OT550 Not supported.
HG813/HG850A/HG851A Supported from the delivery in June 2011.
HG860/HG861 Supported from the delivery in January 2011.
HG863 Replaced from June 2010.
HG8240/HG8240B/HG8240R/HG8240S/HG8240T/HG8240W/HG8245
/HG8245T/HG8010/HG8110/HG8247/HG8247A/HG8447
/HG8120/HG8120R/HG8242/HG8242B/HG8040/HG8247T/HG8045
/HG8244T
Replaced from June 2010.
HG8010A/HG8010H/HG8010U/HG8245A/HG8245H/HG8110H/HG8240A
/HG8240H/HG8240S/HG8240T/HG8240u/HG8045A/HG8012H/HG8247H
/HG8242H/HG8040H/HG8045H/HG8045D/HG8245D/HG8245V/HG8245W5
Supported by all models.