CDM-600 Satellite Modem Revision 7
Open Network Operations MN/CDM600.IOM
9–2
9.2.1 IBS Clock/data recovery and De-jitter
Performs clock and data recovery on the G.703 format. Clock de-jitter and data
encoding/decoding is done as with the IDR configuration.
9.2.2 IBS Framing
Multiplexes/demultiplexes the primary data in compliance with the standard IESS-309
overhead ratio of 1/15 (4 overhead bytes per 60 data bytes) and provides the rate
exchanged transmit clock to the modulator portion of the base modem.
9.2.3 IBS Engineering Service Channel
Bi-directional processing of the components of the ESC channel, including the ASYNC
or SYNC EIA-232 data channel, and fault/alarm indications.
For units with FW version 1.3.1 or greater a second high-rate ESC channel, at up to 1/20th
of the primary data rate, is available, using async EIA-232 format.
9.2.4 IBS Scrambling
Provides the synchronous scrambling/descrambling of the satellite-framed data specified
in IESS-309. Base modem scrambling/descrambling is disabled in this mode.
9.3 Drop and Insert
Primary Data Rates Supported
G.703, EIA-422, V.35 and
Serial LVDS
1544 kbps SD, RD, DDO, IDI
2048 kbps SD, RD, DDO, IDI
Satellite Data Rates Supported
(all have 16/15 overhead)
N x 64 kbps
N = 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, or 24 (T1)
N = 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, 24, or 30 (E1-CCS)
N = 1, 2, 4, 6, 8, 12, 16, 24, 30 (E1-CAS)
Terrestrial Framing Supported G.732/G.733, G.704
Satellite Overhead Rate 16/15 of data rate per IESS-308 Rev. 6 and IESS-309 Rev. 3,
or higher
Timeslot Selection Range 1 to 24 (all T1 modes)
1 to 30 (E1-CAS and E1-CCS)
Arbitrary order, non-contiguous available
Plesiochronous Buffer Sizes Selectable size of 64 to 262,144 bits, in 16-bit steps (with
added limitations for G.704 frame boundaries)