Question 21/V - Test to be carried out on repeaters or regenerators to
check
the efficiency of protection from external interference with local or
remote power feeding
(Continuation of Question 21/V, 1985-1988; revised title and wording)

The study of this Question may entail amendments to Recommendation K.17
based on problems listed below:

-are there any reasons for modifications of existing specifications for
tests on coaxial-pair and symmetric-pair repeaters or regenerators?

-is it useful to extend specifications given in
Recommendation K.17 for power feeding paths and power feeding equipments
of optical fibre systems due to modifications in existing systems.

Note - Broadband ISDN systems with optical fibres may need reconsidering
of existing specifications.

-is it useful to specify testing methods and limits for interference
sources causing no damage but malfunction of power- fed repeaters or
regenerators?

If so, which of the transient sources should be considered:

- transients due to switching operations in power network?

- transients due to discharge of static electricity?

-transients due to partial discharges caused by power feeding voltages
or induced voltages of power lines?

-transients due to operation of lightning arresters in adjacent
telecommunication lines?

-is it necessary to consider the interfering effect of transients only
for digital systems?

-is it advisable to study the interfering effect of steady-state of
electromagnetic fields to power-fed repeaters or regenerators?