ZyXEL Communications 871 Modem User Manual


 
Prestige 871
Benefits
VDSL, the fastest offering of DSL, provides
significantly higher bandwidth than other DSL
technologies. VDSL technology, which is similar to
that of ADSL, uses existing copper wires to deliver
high-speed data services.
The major issues with VDSL technology are the line
codes to be employed, which can be divided into
either single-carrier or multi-carrier modulation
schemes. For example, QAM is the most widely used
form of single carrier systems while DMT, the
standard line code for ADSL, is the primary form of
multi-carrier modulation. Both QAM- and DMT-
based systems can be designed for VDSL
applications. However, DMT modulation
dynamically adapts the bit rate to conditions on the
local loop and offers excellent performance even over
noisy lines.
To provide VDSL service to end users, Telcos in
different areas may have different deployment
strategies unique to their existing and future network
plans. Ethernet in the First Mile (EFM) is increasingly
being adopted by service providers and is being
evaluated by Telcos who have traditionally used ATM
networks in the past. Without the ATM layer,
networks become more cost-effective, flexible, and
efficient. The Prestige 871, which is built without
ATM, perfectly fits the network demands of today and
tomorrow.
ZyXEL's Prestige 871 DMT-based VDSL modem
supports a complete range of speeds ranging from
64Kbps to 25Mbps. Symmetric speeds for the Prestige
871 range up to 25Mbps at 64Kbps increments while
asymmetric speeds range up to 52Mbps downstream
and 26Mbps upstream at 64Kbps increments.
DMT 3/4/5-band,
IP-based VDSL Modem
DMT Modulation — Standard Compliance and Outstanding Performance
The Prestige 871 is a DMT (Discrete Multi-Tone)-based VDSL CPE. DMT
modulation dynamically adapts the bit rate to conditions on the local loop
and offers excellent performance even over noisy lines. Network
administrators become free from manually testing lines and from constantly
adjusting equipment to noise conditions. Both IEEE 802.3ah Ethernet in the
First Mile (EFM) Task Force and IEEE T1E1.4 Working Group selected DMT
as its worldwide VDSL line-coding standard.
Bandwidth of over 25 Mbps Per Port in Full Duplex
The high-bandwidth Prestige 871 allows service providers to simultaneously
deliver a variety of value-added services, such as broadband Internet access
and multiple streaming video channels. With the Prestige 871, small to
medium business users can have much higher bandwidth for both
symmetric and asymmetric applications while home users can enjoy
interactive media-rich entertainment which was previously unavailable.
Triple Play over Existing Copper Wires
With VDSL, traditional “copper wire” telecom operators may begin offering
“triple play” multimedia services such as multiple high-quality digital video
streams, high-speed internet access, and voice services in a way which
provides a user experience similar to today’s other existing distribution
systems (cable, terrestrial, satellite). New revenue can be generated with a
minimal amount of installation time and expense.
Co-existence with Plain Old Telephone Service (POTS), ISDN and Digital Phones
VDSL can be implemented quickly, even if there is only one phone line per
tenant. The existing POTS or ISDN services may be kept while adding new
broadband services.
Best CPE for EFM Applications
Due to Ethernet’s relatively low cost, simplicity, flexibility, ubiquity and
high bandwidth, there has recently been growing momentum in the use of
Ethernet in access networking. Such trends in access networking make the
Prestige 871 a perfect solution for EFM applications.