Accton Technology VM2548 - Manual (Page 14)

About the VDSL Switch-VS2512A
1-2
VDSL Technology
VDSL (Very High Bit-Rate Digital Subscriber Line) is at the high-end of all the DSL
technologies, offering the best combination of fiber optics and copper to provide
high-speed broadband Internet access. VDSL’s primary application is in providing a
broadband data service to multi-tenant residential or commercial buildings. In this
implementation, fiber optic cable carries data from an Internet Service Provider to
the building; then the installed telephone copper wires take the data and deliver it to
individual units within that building.
Figure 1-1. VDSL Application
VDSL provides high-speed Internet access over existing phone lines by making use
of previously unused frequency bandwidth above the voice band. By placing VDSL
signals above the frequency of the voice signal, a VDSL service can coexist on the
same line as other telephone services. VDSL can operate symmetrically, providing
the same data rate in both directions, or asymmetrically, providing a higher data rate
in the downstream (receive) direction than in the upstream (transmit) direction.
VDSL can deliver high-performance online applications, such as high-quality video
and other switched multimedia services. Accton's Ethernet-over-VDSL system
provides robust performance, with a symmetric data rate up to 15 Mbps, and a range
up to 1525 m (5000 ft). Accton’s system is based on advanced VDSL QAM
(Quadrature Amplitude Modulation) technology with adaptive channel equalization
that overcomes bridge taps and other line distortions. Reed-Solomon Forward Error
Correction and interleaving protects against errors due to impulse noise and enables
recovery from signal interruptions. Frequency Division Duplexing (FDD) separates
downstream and upstream channels and allows VDSL signals to coexist with regular
telephone services. A power back-off mechanism is also implemented to reduce
noise from crosstalk in line bundles.
ISP
(Internet)
Central Office
(PSTN)
Punch Down
Blocks /
Patch Panels
PBX
Telephone/Fax
Telephone
ES2002-TS
VDSL CPE
VDSL
Splitter-VM2524
VDSL
Switch-VS2512A
Telephone Line from Central Office
Fiber Optic Link to ISP
Local Servers
(Locally Hosted Services,
Video Servers, Billing)
Existing Phone
Lines to Clients
Multi-dwelling/Multi-tenant Building
Floor 2
Floor 1
Rooms/Clients
Rooms/Clients
VDSL Lines
Line Line
VDSL Spl itter -VM252 4 VDSL Spl itter -VM252 4
VM2524 VM2524
Phone Lines
VM2512 A-4FX-M TRJ-S VM2512 A-4FX-M TRJ-S 100BAS E-FX S inglemo de Mod ule 100BASE- FX Singlemo de Mod ule Expansi on Module
VDSL S witch -VS 2512A VDSL S witch -VS 2512A Reset Reset Power Power Stackin g Stacking Diag Diag Master Master On On
Off Off Up Up Down Down Stackin g Stackin g
VS2512A Conso le Consol e 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 10 10 11 11 12 12 VDSL VDSL 1 1 Activity Activity Link Link Activity Activity Link/Sp eed Link/Spe ed 1 1 2 2 3 3 4 4 Ethern et Ethern et 100-24 0V ~ 5 0-60 H z 1A
ES2002-TS
VDSL CPE