Alcatel-Lucent 7330 - Figure 3-1 VDSL Termination Points

3 — ONT and MDU general and interface technical specifications
Alcatel-Lucent 7330/7302 ISAM FTTN R04.02.42a March 2011 3-9
3FE 54199 AAAA TCZZA Edition 01 ONT Product Information Guide
To ensure high quality delivery of SIP-based VoIP services in SIP Mode 2 (thick
client), Alcatel-Lucent recommends the following values for the bandwidth profile
for each POTS line:
• CIR of 250 Kb/s
• EIR of 250 Kb/s
• DT of 8
For multiple POTS lines providing SIP-based VoIP service in SIP Mode 2, use a
multiple of the recommended per-line EIR and CIR values. For example, with 4
POTS lines, use CIR of 1000 Kb/s, EIR of 1000 Kb/s, and DT of 8.
3.5 VDSL2 interface specifications
Similar to ADSL, VDSL2 operates over the copper wires in a telephone line to
provide both high-bandwidth service and POTS, and is asymmetric in its
downstream and upstream speeds. However, VDSL2 provides subscribers with a
higher bit rate than multi-ADSL and can achieve speeds over 57 Mb/s downstream
and 25 Mb/s upstream, compared with 24 Mb/s downstream and 1.3 Mb/s upstream
with multi-ADSL. The maximum bit rates supported depend on deployment, noise
environment, and Ethernet system restrictions. The high bit rate asymmetrical mode
can be used for high-bandwidth video service, while the symmetrical bit rate mode
can be used for business users or residential users who need symmetrical bit rate
access. The VDSL2 ports support loop lengths of 300 meters nominal.
VDSL allows very high speed data transmission on a metallic twisted pair between
the operator network and the customer premise. This service is provisioned by using
the existing unshielded copper twisted pairs, without requiring repeaters. By using a
Frequency Division Multiplexing technique, the existing POTS or BR ISDN services
can still be provided on the same wires. VDSL transceivers use Frequency Division
Duplexing (FDD) to separate upstream and downstream transmission.
Each end of the VDSL line is terminated by a VDSL Termination Unit (VTU), as
shown in 3-1. The unit at the (optical) network side is the VTU-O (MDU) and the
Remote or Customer Premises (CP) unit is the VTU-R.
The High Pass Filter (HPF) blocks the POTS/ISDN signals towards the VTU, and
the Low Pass Filter (LPF) blocks the VDSL signal towards the Local Exchange
(VTU-O side) or telephone set (VTU-R side).
Figure 3-1 VDSL Termination Points
Downstream
Metallic
twisted pair
Synchronization
signals
OAM
Data
signals
Data
signals
POTS signals
to CO
POTS
splitter
POTS
splitter
POTS signals
to CPE
Upstream
VTU-O
VTU-R
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