Parameters which are Approved by TRCSL for Mobile Phone

Genaral Requirment

1. DC resistance

Justification:  Inter-working with the PSTN is assured by requiring the TE to present a sufficiently high DC resistance in quiescent state so as not to disturb the basic call control and to prevent the malfunction of network call control equipment.

Requirement: The current drawn by the TE when connected to a source of:

- 100 VDC;
- 50 VDC;
- 25 VDC,

 shall not exceed that which would be drawn by a 1 MΩ resistor replacing the TE. This requirement applies 30 seconds after the voltage has been applied.

2. Impedance

Justification: Inter-working with the PSTN is assured by requiring the TE to present an impedance to ringing signals that is sufficiently high. 

Requirement: The impedance of the TE at frequencies of 25 Hz and 50 Hz shall not be less than 4 kΩ when tested at 30 V rms.