Nortel Networks 1000 - Manual (Page 877)

Architecture 877
NTBK50 interfaces to one DS-30X bus which contains 32-byte interleaved
timeslots operating at 2.56 Mb. Each timeslot contains 10 bits in A10
message format; eight are assigned to voice/data (64 Kbps), one to
signaling (8 Kbps), and one is a data valid bit (8 Kbps).
The incoming serial bit stream is converted to 8-bit parallel bytes to be
directed to padding control. The signaling bits are extracted and inserted
by the A07 signaling interface circuitry. Timeslots 0 and 16 are currently
unused for PCM.
Digital PAD
The software selects A-Law or µ-Law and one of 32 possible PAD values
for each channel. These values are provided in a PROM through which
the data is routed. The idle code for A-Law is 54H and for µ-Law is 7FH.
The unequipped code is FFH for both A-Law and µ-Law.
As the idle code and unequipped code can be country dependent, the
software instructs the NTBK50 to use different codes for each direction.
The 32 digital pads available are illustrated in
Table 370 "Digital Pad
- values and offset allocations" (page 877) . The values shown are
attenuation levels (1.0dB is 1 dB of loss and –1.0 dB is 1 dB of gain.
Table 370
Digital Pad - values and offset allocations
PAD SET 0 PAD SET 1
Offset PAD Offset PAD
0 0.6 dB 0 0.0 dB
1 1.0 dB 1 -1.0 dB
2 2.0 dB 2 -2.0 dB
3 3.0 dB 3 -3.0 dB
4 4.0 dB 4 -4.0 dB
5 5.0 dB 5 -5.0 dB
6 6.1 dB 6 -6.0 dB
7 7.0 dB 7 -7.0 dB
8 8.0 dB 8 -8.0 dB
9 9.0 dB 9 -9.0 dB
10 10.0 dB 10 -10.0 dB
11 11.0 dB 11 spare
12 12.0 dB 12 spare
13 13.0 dB 13 spare
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 02.06 Standard
27 August 2008
Copyright © 2003-2008 Nortel Networks
.