CDM-600 Satellite Modem Revision 7
Clock Modes and Drop and Insert (D&I) MN/CDM600.IOM
10–7
10.5 Frame Formats
The E1 and T1 frame formats that are supported are shown in Figure 10-3:
Figure 10-3 Supported T1 and E1 Framing formats
Note that for D&I++, the smaller overhead frame structure does not support CAS
signaling, although E1 timeslot 16 may still be one of the channels transmitted.
123456789101112131415 161718192021222324252627282930
012345678910111213141516171819202122232425262728293031
123456789101112131415 161718192021222324252627282930
012345678910111213141516171819202122232425262728293031
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E1-CCS (Common Channel Signalling)
2048 kbps E1 Frame Maximum channels to drop = 30 = 1920 kbps n x 64 kbps, n = 1, 2,3,4,5,6,8,10,12,15,16,20,24,30
Time
Slot
No.
Time
Slot
No.
Reserved for
Framing
Reserved for
Framing
May be reserved for Signalling. All signalling
information is common to all 30 TS and no signalling is
transmitted.
Reserved for Signalling. All signalling is transmitted
for TS's dropped in IBS overhead (500Hz per TS)
Signalling information in TS 16 is associated to
specific TS's.
E1-CAS (Channel Associated Signalling)
2048 kbps E1 Frame Maximum channels to drop = 30 = 1920 kbps n x 64 kbps, n = 1,2,4,6,8,12,16,24,30
Time
Slot
No.
Time
Slot
No.
T1-D4 (D4 Framing)
1544 kbps T1 Frame 12-Frame multi-frame structure. No IBS multi-frame signalling will be transm itted.
Maximum channels to drop = 24 = 1536 kbps n x 64 kbps, n = 1,2,3,4,5,6,8,10,12,15,16,20,24
T1-ESF (Extended Super Frame)
1544 kbps T1 Frame 24-Frame multi-frame structure. No IBS multi-frame signalling will be trans mitted.
Maximum channels to drop = 24 = 1536 kbps n x 64 kbps, n = 1,2,3,4,5,6,8,10,12,15 ,16,20,24