Data sheet
MH89790B
BIT
NAME
DESCRIPTION
7,
6,
A(N),
B(N),
Receive Signalling Bits for Channel N: These are the bits which are received from the CEPT 2048 kbit/s
link in bit positions 1 to 4 of timeslot 16 in frame N (frame #), and are the A, B, C and D signalling bits
associated with telephone channel N. The value of N lies in the range 1 to 15 and refers to the channel on
the CSTo stream on which the bits are output, the telephone channel with which the bits are associated and
the frame on the CEPT link on which the bits are received. For example, the bits output on the CSTo stream
on channel 3 are associated with telephone channel 3, which is timeslot 3 of the CEPT link, and are
received on bits positions 1 to 4 of timeslot 16 in frame 3 of each multiframe on the CEPT link. If bits B, C
or D are not used they should have the values ‘1, 0‘ and ‘1’, respectively. The combination ‘0000‘ for
ABCD bits should not be found for telephone channels 1 to 15 as this implies interference with multiframe
alignment.
5
C(N)
& 4
& D(N)
3,
2,
A(N+15),
B(N+15),
C(N+15)
Receive Signalling Bits for Channel N+ 15: These are the bits which are received from the CEPT 2048
kbit/s link in bit positions 5 to 8 of timeslot 16 in frame N, and are the A, B, C and D signalling bits
associated with telephone channel N+15. The value of N lies in the range 1 to 15 and refers to both the
channel on the CSTo stream where the bits are output and the frame on the CEPT link on which the bits are
received, and indirectly indicates the telephone channel with which the bits are associated. The associated
channel is N+15.
For example, the bits output on the CSTo stream on channel 3 are associated with telephone channel 18,
which is timeslot 19 of the CEPT link, and are received on bits positions 5 to 8 of timeslot 16 in frame 3 of
each multiframe on the CEPT link.
1
& 0
& D(N+15)
Table 11 Received Channel Associated Signalling: Data Format for CSTo Channels 1 to 15
BIT
7
NAME
IU0
DESCRIPTION
International Use 0: This is the bit which is received from the CEPT 2048 kbit/s link in bit position 1 of
timeslot 0 of frame-alignment frames. It is reserved for the CRC remainder or for international use.
6-0
FAF2-8
Frame Alignment Signal Bits 2 to 8: These are the bits which are received from the CEPT 2048 kbit/s
link in bit positions 2 to 8 of timeslot 0 of frame-alignment frames. These bits form the frame alignment
signal and should have the values of ‘0011011‘.
Table 12 Received Frame Alignment Signal: Data Format for CSTo Channel 16
BIT
7
NAME
DESCRIPTION
IU1
International Use 1: This is the bit which is received from the CEPT 2048 kbit/s link in bit position 1 of
timeslot 0 of non-frame-alignment frames. It is reserved for CRC framing bits or international bits.
6
5
NFAF
Receive Non-Frame Alignment Bit: This is the bit which is received from the CEPT 2048 kbit/s link in
bit position 2 of timeslot 0 of non-frame-alignment frames. This bit should be ‘1‘ in order to differentiate
between frame-alignment frames and non-frame-alignment frames.
ALM
Non-Frame Alignment Alarm: This bit is received from the CEPT 2048 kbit/s link in bit position 3 of
timeslot 0 of non-frame-alignment frames. It is used to signal an alarm from the remote end of the CEPT
link. This bit should have the value ‘0‘ under normal operation and should go to ‘1 ‘to signal an alarm.
4-0
NU1-5
National Use: These are the bits which are received on the CEPT 2048 kbit/s link in bit positions 4 to 8 of
timeslot 0 of non-frame-alignment frames. These bits are reserved for national use, and on crossing
international borders they should have the value ‘1‘.
Table 13 Received Non-Frame Alignment Signal: Data Format for CSTo Channel 17
Zarlink Semiconductor Inc.
11
ZARLINK [ ZARLINK SEMICONDUCTOR INC ]
