ES 202 971 : 1.2.1

Intellectual Property Rights
Foreword
Introduction
1 Scope
2 References
3 Definitions, symbols and abbreviations
   3.1 Definitions
   3.2 Symbols
   3.3 Abbreviations
4 General
5 Physical connections
   5.1 Mechanical aspects
   5.2 Support of more than one terminal
6 DC feed conditions
   6.1 Polarity
   6.2 Quiescent state
   6.3 Loop current
7 Seize signal
   7.1 Must not seize condition
   7.2 Must seize condition
8 Clear signal
   8.1 Clear signal generated by TE
   8.2 Clear indication from the network
   8.3 Seizing the line for a new call
9 Impedance
   9.1 Impedance at the R interface
   9.2 Balance about earth
10 Transmission
   10.1 Relative level
   10.2 Variation of gain with input level
   10.3 Frequency response
   10.4 Coding law
   10.5 Noise
   10.6 Echo and stability
   10.7 Crosstalk
   10.8 Total distortion including quantizing distortion
11 DTMF Dialling
12 Ringing
   12.1 Ringing drive capability
   12.2 Ring cadence
   12.3 Ring trip
   12.4 False ring trip
13 Supervisory signals
   13.1 Supervisory tones
   13.2 Tone levels
   13.3 Cadences and frequencies
14 Optional functions
   14.1 Loop disconnect dialling
   14.2 Register recall
   14.3 Metering
   14.4 Supplementary and other enhanced services
   14.5 Polarity reversal
   14.6 End of call signal ("K-break")
   14.7 Payphones
Annex A (informative): Test set-up for the change from DC
        to ringing voltage
Annex B (informative): Bibliography
History

Describes the physical and electrical characteristics at an analogue interface. It also specifies characteristics of the interface to enable it to operate with most existing national PSTN TE, and especially with PSTN TE designed according to the European standards for analogue presented TEs.