6 — LP MDU, MDU, and modular ONT hardware functional blocks
6-10 July 2008 Alcatel-Lucent 7342 ISAM FTTU ONT R04.05.06
ONT Product Information Manual Edition 01 3FE 51892 AAAA TCZZA
Assumptions for the RF measurements:
• Channel load = 80 analog and 33 QAM
• Digital channel backoff = 6 dB
• Video TX OMI = ~3.4%
• RF optical range = + 1.0 dB to - 6.0 dB
SWRD
Figure 6-3 illustrates the SWRD functional blocks.
Figure 6-3 SWRD functional blocks
Use of a Single Wire Return Device (SWRD) is recommended when a customer with
LP MDU ONTs featuring RF video requires upstream connectivity to implement a
video return channel.
The SWRD has two 10/100 Ethernet ports and 2 RF ports. The SWRD is powered
from the ONT by an Ethernet cable once the SWRD is installed and an Ethernet UNI
is provisioned. An Ethernet UNI connection provided by the optional SWRD is used
for the video return channel. Used in conjunction with an SWRD, the STB
communicates upstream using traditional QPSK RFV transmission instead of
sending all upstream communication using an Ethernet transport.
A single CATV-compatible RF interface is used to provide CATV service. For
CATV service, an RF video signal is passed in the downstream direction to external
video distribution equipment. In the upstream direction, the return channel is carried
over an Ethernet port to the ONT.
6.3 O-00240V-A MDU ONT functional blocks
The O-00240V-A MDU ONT consists of a single board that provides 24 VDSL2
ports supporting all ETSI 17a/30a VDSL2 band plans. The O-00240V-A MDU ONT
employs an architecture that is based on the first generation modular GPON MDU
reusing some of the primary core blocks. The use of the Ethernet switch to perform
packet forwarding between the GPON MAC FPGA and the VDSL2 chips is the
major difference between the O-00240V-A MDU ONT and earlier GPON MDU
implementations.
1958
GPON
PCI
MII
ODB
GPON
MAC
PHY
BCM 5696
12G PORTS
SWRD
UNI
SWRD Upstream data path
OBC
MPC 8347
BCM 5464
QUAD PHY
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