User's Manual

Technical specifications

Tabel 7: Wavelength planning

In order to accomplish to that plan, the upstream wavelength for GPON must be restricted to ONU (ONT)

equipment based on the ordinary DFB lasers, while the XGPON downstream signal range is defined

from 1575 nm to 1580 nm and the XGPON upstream signal from 1260 nm to 1280 nm. For the

coexistence of XGPON and GPON over the same fiber, the CO requires a WDM filter that combines the

downstream signal (1490 nm, 1555 nm and 1577 nm), isolating the 1310 nm and 1270 nm upstream

signal, with the video signal. Also the wavelength of 1650 nm, used for fiber monitoring, has to be

handled.

In addition, ONT devices require the use of a triplexer type transceiver that include an integrated filter

or a discrete WDM filter to distinguish the different signals that may be present on the fiber. The current

networks, equipped with ONT in accordance with the current ITU-T Rec. G984.5, will be easily updated

to XGPON.

Class B+ optical budget are the nominal requirement for coexistence of GPON and XGPON over the

same optical fiber. Taking this requirement into account, the fiber network architecture will not limit the

future of the service provider business since GPON architectures, respecting B+ class of the GPON,

are easily updated by placing newest terminal equipments, namely XOLT and XONT, and by replacing

the current WDM filter by the new one in order to handle the new XGPON signals.

XGPON must support/emulate all GPON legacy services in case of total migration.

Like GPON, XGPON is required to support triple play services (data, voice and video), as well as

mobile backhauling (accurate frequency/phase/time synchronization) application through its high quality

of service and high bit rate feature capabilities. Access to Ethernet services such as point-to-point,

multipoint-to-multipoint and rooted-multipoint Ethernet Virtual Connection services should be provided.

Finally, as a global requirement, XG-PON needs to support IPv6.

3.6 GPON/Ethernet characteristics

GPON/Ethernet characteristics supported, both functional level and GTC-OMCI configuration,

corresponds with the general mandatory characteristics defined in ITU-T G.984.3, G.984.4 and G.988

Recommendation:

• PON interface: downstream operating rate 2.488 Gbits/s, upstream operating rate 1.244

Gbits/s;

• 32 T-CONT and 256 simultaneous GEM ports;

• 1:64 SR is granted once optical power transmission from the OLT side is up from -27/30dBm;

• Unmarked or marked bandwidth management;

• Upstream and downstream FEC;

• Downstream AES encryption;

• Ethernet flow control in client´s port: 802.3x and 802.3ab;

• Ability to classify and modify VLAN labels (single or double labeling);

• Ability to support multiple VLAN tags per service (Internet, IPTV, VoIP, ACS, etc) from

Residencial Gateway. And ability to translate those VLAN to one specific service VLAN on OLT