
PEB 80900
Part II
’
IEC-T
’
: General Description
Data Sheet
70
2001-04-02
5.1
Basic System Functions
Full duplex transmission and reception of the Uk0 interface signals according to the
FTZ Guideline 1 TR 220 of the Deutsche Bundespost (DBP).
–
144 kbit/s user bit rate over standard local telephone loops.
–
1 kbit/s maintenance channel for transmission of data loop back commands and
detected transmission errors.
–
4B3T ternary block code (subscriber line symbol rate 120 kbaud).
–
Monitoring of transmission errors.
–
Subscriber loop length without repeater:
up to 4.2 km on 0.4 mm wire
up to 8.0 km on 0.6 mm wire
Adaptive echo cancellation.
Adaptive equalization.
Automatic polarity adaption.
Clock recovery (frame and bit synchronization) in all applications.
Transposition of ternary to binary data and vice versa (coding, decoding, scrambling,
descrambling, phase adaption).
Built in wake-up unit for activation from power-down state.
Activation and deactivation procedure according to CCITT I.430 and to FTZ Guideline
1 TR 210 of the DBP.
Adaption of internal interfaces to the current signal direction by programmable
operation modes:
–
LT:
Line termination in public or private exchange
–
NT:
Network termination connected to SBC
–
NT-PABX:
Trunk module (TMD)
–
NT-TE:
Terminal equipment
–
LT-RP:
U Repeater unit subscriber side
–
NT-RP:
U Repeater unit exchange side
Optimized for working in conjunction with SBC and ICC telecom IC's via IOM
interface.
Data speed conversion between the Uk0 frames and the IOM
frames. In the LT and
NT-PABX modes, absorption of received phase-wander of up to 18 μs peak to peak
(CCITT Rec. Q.512).
Handling of commands and indications contained in the IOM
C/I channel for (de-)
activation, supervision of power supply unit and equipment for wire testing.
Data availability via the MONITOR channel:
–
accumulated RDS transmission errors; in the LT mode for the whole Uk0 link, in the
NT mode only for those detected in the circuit itself.
–
measurement value of the loop current.
–
Echo canceller coefficients and status values, which can be used to indicate the
state of the Uk0 interface.