PEF2091 Siemens Semiconductor Group, PEF2091 Datasheet - Page 245

• Manufacturer Part Number: PEF2091
• Description: ICs for Communications(ISDN Echocancellation Circuit)
• Manufacturer: Siemens Semiconductor Group

6.8.7
When the terminal requests to activate the S-interface (U-interface already active) two
cases can occur:
In the first case the exchange has retained control over the S-interface activation. Then
S-activation can proceed only after the explicit permission by the exchange with AR. This
situation is discussed in this section under "case 1". In the second case the exchange is
not requested to send AR in order to continue activation. This situation is described in
"case 2" of this section.
The terminal recognizes no difference between the two types, the procedure on NT side
consequently is identical in both cases.
Case 1 (controlled by exchange)
<–––––
–––––>
–––––>
<–––––
–––––>
<–––––
Case 2 (no control by exchange)
<–––––
–––––>
–––––>
<–––––
–––––>
<–––––
Semiconductor Group
NT
C/I DC
C/I DI
C/I AR
C/I AR
C/I AI
C/I AI
NT
C/I DC
C/I DI
C/I AR
C/I AR
C/I AI
C/I AI
Complete Activation Initiated by TE with U Active
(1111
(1000
(0011
(1111
(1000
(1100
(1100
(1111
(1000
(1000
(1100
(1100
B
B
B
B
B
B
B
B
B
B
B
B
)
)
)
)
)
)
)
)
)
)
)
)
LT
C/I UAR
C/I UAI
C/I AR
C/I AR
C/I UAI
C/I AI
LT
C/I DC
C/I UAI
C/I AR
C/I UAI
C/I AI
(0111
(0111
(1000
(1000
(0111
(1100
(0111
(1000
(0111
(1100
245
B
B
B
B
B
B
B
B
B
B
)
)
)
)
)
)
)
)
)
)
–––––> ;
<––––– ;
–––––>
–––––> ; Exchange is notified of
–––––>
<––––– ; U only is activated
–––––>
–––––> ; Activation complete
<––––– ; U only is activated
–––––>
–––––> ; Activation complete
;
;
;
;
;
;
;
;
; proceeding S-activation
;
;
activation
Exchange is notified of
request
Exchange permits
S-activation
Confirm that terminal is
active
Terminal requests
activation
Confirm that terminal is
active
Terminal requests
Data Sheet 01.99
Programming
PEB 2091
PEF 2091