Comtech EF Data CDM-625A - Manual (Page 598)

CDM-625A Advanced Satellite Modem MN-CDM625A
Appendix E Revision 3
E–8
E.7 Timeslot Selection
Selection of the transmit and receive data rates may be made in certain 64 kbps increments and
may be independent of each other. The actual satellite rates for open network D&I are 16/15 of
the transmit or receive data rate to include IBS overhead per IESS
-
309, although this is
transparent to the user.
For E1, you can select any timeslot (TS) from 1 to 31. Selection of TS 0 is permitted (on the front
panel menus, use ‘z’ to add to the list of timeslots to be dropped/inserted).
For T1, you can select any timeslot (TS) from 1 to 24. You may also select “N/A” to leave a
satellite channel unused.
The configuration menu allows timeslots to be selected for transmission or reception up to the
maximum dictated by the selected transmit or receive data rate, and may be selected in
arbitrary order. For example, if the data rate is set to 256 kbps, the maximum number of
timeslots that can be dropped or inserted is 4 (being 4 x 64 kbps).
Note that, for 1920 kbps data rate, the timeslots may not be manipulated. This is the ‘fixed
channel’ mode where Timeslot 1 is assigned to Channel 1, and so on.
For D&I++ framing, all increments of 64 kbps are allowed up to a maximum of 31 (1984 kbps).
For this mode, the satellite rate is 46/45 of the front panel data rate (2.22%).