Page 38 of 290
Description
553-3001-105
Standard 5.00
June 1999
Figure 14
Battery reversal answer and disconnect supervision sequence
Meridian 1
High-
resistance
loop
Line card unit idle
(2-way voice
connection)
Remarks
Ground on tip/
battery on ring
Signal/direction
State
Ground on tip/
battery on ring
High-
resistance
loop
Ground on tip/
battery on ring
Far-end station
on hook
Near-end station
on hook
If near-end station hangs up first, a high-resistance loop is
presented to the Meridian 1.
If far-end station hangs up first, the Meridian 1 detects
disconnect signalling from the far end, removes timeslot
assignments, and restores normal ground/battery polarity
to the near-end station.
No battery current drawn.
Near-end station goes off hook. Battery current is drawn
causing detection of off-hook state. Meridian 1
determines unit terminal number (TN) and assigns
message timeslots.
Low-resistance loop
Dial tone is applied to the near-end station from the
Meridian 1.
Call request
Dial tone
Addressing signals
Outpulsing
Near-end station dials number (loop pulsing or DTMF
tones).
Dial tone removed
Meridian 1 detects start of dialing and removes dial tone.
Ringback (or busy)
Meridian 1 decodes addressing, routes call, and supplies
ringback tone to near-end station if far-end station is on
hook. (Busy tone supplied if far-end station is busy.)
When call is answered (either absolute or assumed
answer, as programmed), ringback tone is removed, call
is cut through to far-end station, and battery is reversed
to near-end station for duration of call.
Meridian 1 detects drop in loop current, removes timeslot
assignments, sends disconnect signal to far-end station,
and restores normal ground/battery polarity to the near-
end station. Line card unit is then ready for the next call.
High-
resistance
loop
Near-end station detects battery reversal and goes on
hook. Line card unit is then ready for the next call.
High-
resistance
loop
Line card unit idle
Line card unit idle
Low-
resistance
loop
Line
card
Near-end
station
Far-end
station
Battery on tip/
ground on ring
Low-
resistance
loop
Battery on tip/
ground on ring
Ground on tip/
battery on ring
Note 1:
Battery reversal signalling is a supervisory feature that is only used when the near-end station
originates the call.
553-7517
Содержание NT1R20
Страница 2: ......
Страница 4: ...iv 553 3001 105 Standard 5 00 June 1999 iv ...
Страница 12: ...xii Contents 553 3001 105 Standard 5 00 June 1999 ...
Страница 76: ...Page 52 of 290 Description 553 3001 105 Standard 5 00 June 1999 ...
Страница 98: ...Page 74 of 290 NT1R20 Off Premise Station Analog Line Card 553 3001 105 Standard 5 00 June 1999 ...
Страница 154: ...Page 130 of 290 NT5D11 Line side T1 Interface Card 553 3001 105 Standard 5 00 June 1999 ...
Страница 216: ...Page 192 of 290 NT5D33 and NTRB34 Line side E1 Interface Cards 553 3001 105 Standard 5 00 June 1999 ...
Страница 264: ...Page 240 of 290 QPC192 Off Premise Extension OPX Analog Line Card 553 3001 105 Standard 5 00 June 1999 ...
Страница 276: ...Page 252 of 290 QPC452 Basic 500 2500 Analog Line Card 553 3001 105 Standard 5 00 June 1999 ...
Страница 302: ...Page 278 of 290 QPC789 16 port Message Waiting Analog Line Card 553 3001 105 Standard 5 00 June 1999 ...
Страница 306: ...Page 282 of 290 List of terms 553 3001 105 Standard 5 00 June 1999 ...
Страница 314: ...Page 290 of 290 553 3001 105 Standard 5 00 June 1999 ...
Страница 315: ......