High Speed Transmission Equipment
High Speed Transmission Equipment
High speed transmission equipment encompasses a broad range of transmission protocols
such as T1/E1, xDSL, and ISDN. Transmission equipment is located at the central office,
customer premises, and remote locations.
Protection Requirements
Transmission equipment should be protected against overvoltages that can exceed 2500 V
and surge currents up to 500 A. In Figure 3.7 through Figure 3.17, SIDACtor devices were
chosen because their associated peak pulse current (IPP) rating is sufficient to withstand the
lightning immunity tests of GR 1089 without the additional use of series line impedance.
Likewise, the fuse shown in Figure 3.7 through Figure 3.17 was chosen because the
amps2time (I2t) rating is sufficient to withstand the lightning immunity tests of GR 1089, but
low enough to pass GR 1089 current limiting protector test and power cross conditions
(both first and second levels).
The following regulatory requirements apply:
•
•
•
•
TIA-968 (formerly known as FCC Part 68)
GR 1089-CORE
ITU-T K.20/K.21
UL 60950
Most transmission equipment sold in the US must adhere to GR 1089. For Europe and
other regions, ITU-T K.20/K.21 is typically the recognized standard.
ADSL Circuit Protection
Asymmetric Digital Subscriber Lines (ADSLs) employ transmission rates up to 6.144 Mbps
from the Central Office Terminal (COT) to the Remote Terminal (RT) and up to 640 kbps
from the RT to the COT at distances up to 12,000 feet. (Figure 3.7)
Central Office Site
Local Loop
Remote Site
ADSL
transceiver
unit
ADSL transceiver unit
ATU-C
video
voice
Digital
Network
ATU-R
data
Splitter
PSTN
POTS
up to 12 kft
Figure 3.7 ADSL Overview
© 2002 Teccor Electronics
3 - 7
http://www.teccor.com
+1 972-580-7777
®
SIDACtor Data Book and Design Guide
TECCOR [ TECCOR ELECTRONICS ]
