PEF2091 Siemens Semiconductor Group, PEF2091 Datasheet - Page 246

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

Semiconductor Group
6.8.8
The following example shows the procedure for deactivating the S-interface only while
leaving the U-interface active.
<–––––
–––––>
<–––––
–––––>
<–––––
6.8.9
For LT and NT the activation procedure with a repeater between exchange and network
is identical to that described at the beginning of this chapter. The repeater transforms the
received U-signals into C/I-codes and monitor messages. These codes and messages
pass the repeater control unit (e.g. µP). In this control unit a number of adaptations are
made to comply with a specific national specification.
In this section only C/I-codes are considered which need to be transformed by the control
unit such that the repeater counterpart will operate correctly. In addition overhead bits
and the specified 2B+D data needs to be transferred for a correct repeater
activation/deactivation.
In order to recognize the dependence of LT-RP and NT-RP-signals more easily, the
arrows point towards the middle.
When activating the repeater unit from the exchange side, the UAI-code issued by the
LT-RP needs to be converted into AI for the NT-RP.
C/I DC
C/I DI
C/I AR
C/I AR
C/I ARM
C/I UAI
C/I AI
LT-RP
NT
C/I AI
C/I AI
C/I DR
C/I DI
C/I DC
Deactivating S/T-Interface Only
Activation Initiated by LT with Repeater
(1111
(1111
(1000
(1000
(1001
(0111
(1100
B
B
B
B
B
B
B
)
)
)
)
)
)
)
(1100
(1100
(0000
(1111
(1111
<––––– <––––– C/I PU
–––––> –––––> C/I TIM
<––––– <––––– C/I DC
–––––> <––––– C/I AR
–––––>
–––––> –––––> C/I AI
–––––> <––––– C/I AI
B
B
B
B
B
)
)
)
)
)
LT
C/I AI
C/I AR
C/I UAR
C/I UAI
[C/I DC
NT-RP
(1100
(1000
(0111
(0111
(1111
246
B
B
B
B
B
)
)
)
)]
)
–––––> ; Initial state: layer 1 activated
<–––––
<––––– ; Deactivate S-interface only
–––––> ; S-interface is deactivated
<––––– ; Exchange retains no control
(0111
(0000
(1111
(1000B)
(1100
(1100
B
B
B
B
B
) ; Initial state "Power Up" to
)
) ; Activation started by LT
)
) ; Activation complete
; Activation proceeds
provide timing
Data Sheet 01.99
Programming
PEB 2091
PEF 2091