Preliminary Information
MH89790B
BIT
NAME
DESCRIPTION
7,
6,
5
A(N),
B(N),
C(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.
& 4
& D(N)
3,
2,
1
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 are associated. The associated channel is N+15.
& 0
& D(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 .
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
IU1
DESCRIPTION
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
ALM
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.
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
4-197
MITEL [ MITEL NETWORKS CORPORATION ]
