Circuit Protection for T1/E1, T3/E3, xDSL, and POTS
T1/E1 and T3/E3 are the first and third generations of digitally multiplexed carrier signals. The T-carriers are prominent in N. America, Japan and S. Korea while the E carriers are used in the rest of the world. Maximum bit rates for these systems are shown in the table below.
DSL, ADSL, VDSL and various versions of these are concurrent standards for transmitting digital data on legacy phone lines. Voice (telephone) and xDSL signals are multiplexed on the same twisted pair using multi-tone frequency-division-multiplexing. An isolation transformer enables the translation of xDSL signals to the telephony voltage.
T1/E1 links (< 2Mbps) and T3/E3 links (< 43Mbps) are susceptible to ESD strikes, cable-discharge events and lightning-induced transients.
xDSL lines (< 52Mbps) are susceptible to ESD strikes, cable-discharge events and lightning-induced transients.
Tertiary & Secondary Protection Used: TSPDs
TVS - Transient Voltage Suppressors
TSPD - Thyristor Surge Protection Devices