Zyxel VES-1624FT-55A [102/312] Impulse noise protection inp

Zyxel VES-1624FT-55A [102/312] Impulse noise protection inp
Chapter 16 xDSL Port Setup
VES-1624FT-55A User’s Guide
102
16.4.6 Impulse Noise Protection (INP)
Short impulses from external sources may cause bursts of errors which could impact the
multimedia (ex. voice, video, or picture) quality. VDSL2 supports Impulse Noise Protection
(INP) which provides the ability to correct errors regardless of the number of errors in an
errored DMT (Discrete Multi-Tone) symbol.
16.4.7 UPBO
In a network with varying telephone wiring lengths, the PSD on each line is different. This
causes crosstalk between the lines. Enable UPBO (Upstream Power Back Off) to allow the
device to adjust the transmit PSD of all lines based on a reference line length. This mitigates
the upstream crosstalk on shorter loops to longer loops. It allows the IP DSLAM to provide
better service in a network environment with telephone wiring of varying lengths.
An example is shown below. Line 1 and Line 2 are in the same cable binder. Crosstalk occurs
when the signal flows and is near to CPE (A)s location. Besides, higher Line 1 PSD causes
higher interference to the Line 2. CO receives signal with higher attenuation. With UPBO
enabled on the CPE (A), it decreases the PSD level and reduces the crosstalk impact on long
loops.
Figure 45 UPBO Resolves Upstream Far-End Crosstalk
16.4.8 DPBO
VDSL signal may interfere with other services (such as ISDN, ADSL or ADSL2 provided by
other devices) on the same bundle of lines due to downstream far-end crosstalk. DPBO
(Downstream Power Back Off) can reduce performance degradation by changing the PSD
level on the VDSL device(es) at street cabinet level.
ISDN in Europe uses a frequency range of up to 80 kHz, while ISDN in Japan uses a
frequency range of up to 640 kHz. ADSL utilizes the 1.1 MHz band. Both ADSL2 and ADSL
2+ utilize the 2.2 MHz band.
Central
CPE (A)
CPE (B)
Site (CO)
Line1 (150m)
Line2 (600m)
No-UPBO
UPBO

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