IEC TS 61873:2001 pdf download
IEC TS 61873:2001 pdf download.State of the art for symmetrical pair/quad cables with transmission characteristics beyond category 5.
3.2.5 Mutual capacitance
The mutual capacitance is not specified but may be indicated, for information purposes. in the
appropriate detail specification.
32.6 Pair to earth capacitance unbalance
When measured at a frequency of 1 kHz, the maximum pair to earth capacitance unbalance shall not exceed 1 600 pFkm.
3.2.7 ResIstance of the screen
The d.c. resistance of the screen is not specified but may be indicated in the appropriate detail specification.
3.3 TransmissIon characteristics
All the tests shall be carried out on a cable length of 100 m, unless otherwise stated.
3.3.1 VelocIty of propagation
The minimum phase velocity of any pair within the cable shall not be less than 0,6 c for all frequencies from 4.0 MHz to the maximum referenced frequency.
3.3.2 Phase delay Under consideration.
3.3.3 Differential delay (skew)
3.3.3.1 Maximum differential delay
When the phase delay is measured at —20 C ± 2 C, 20 C ± 3 C and 60 C ± I °C, the maximum differential phase delay (skew) at a given temperature shall not exceed 25 ns for 100 m, for frequencies from 4,0 MHz to the maximum referenced frequency. As an exception, the differential delay for C-120 shall not exceed 45 ns for 100 m.
3.3.3.2 Environmental effects
The differential delay (skew) between all pair combinations due to the temperature shall not vary by more than ±10 ns over the temperature range from —20 °C to +60 C.
3.3.4 Impedance
3.3.4.1 Input impedance
The impedance measured in a swept frequency mode (open, short Circuit method of 3.3.6.1 of IEC 61158.1) shall meet the requirements Indicated in table 2 for all frequencies from 1.0 MHz to the maximum referenced frequency.
The cables referenced in this technical specification are intended for generic cabling systems. having solid conductors and with a pair count of four pairs or less, Their electrical perlormance requirements are laid out such that a margin of 3 dB is guaranteed for the channel, which approximately corresponds to 10 dB per 100 m of cable, it the connecting hardware and the patch cords are taken into account.
The cables may be provided without a screen, with a common screen or with individual screens over the pairs.
These cables are intended for various new communication systems, which are under development, and which may use as many as four pairs simultaneously. In this sense, the present specification is intended as a working document for system developers, to allow the evaluation of complete systems from a technical and also from an economic point of view.
The cables covered by this specification are intended to operate with the voltage and current levels normally encountered in communication systems. These cables are not intended to be used in conjunction with low impedance sources, for example the electric power supplies of public utility mains.
The recommended temperature range during installation may be indicated in the detail specification.
The operating temperature range is at least —20 C to +60 °C in order to ensure that a connected link remains operational under normal temperature variations, (The output and receive amplifiers go, upon power-up, through a training which takes the line condition into account and compensates for it, After training, the amplifiers are locked, to maintain the established parameters. If the line conditions are changed beyond the specified level, then the bit error rate of the linecard exceeds the permissible threshold and the link is interrupted.)
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this Technical Specification. For dated references, subsequent amendments to. or revisions of, any of these publications do not apply. However, parties to agreements based on this Technical Specification are encouraged to Investigate the possibility of applying the most recent editions of the normative documents Indicated below. For undated references, the latest edition of the normative document referred to applies. Members of IEC and ISO maintain registers of currently valid International Standards.
IEC 60344:1960, Guide to the calculation 01 resistance of plain and coated conductors of low- frequency cables and wires
IEC 61156-1:1994, Multicore and symmetrical passr/quad cables for digital communications — Part 1: Generic specification.
