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Channel # 1 Satellite Data Rates
Channel # 1 Terrestrial Framing
Channel # 1 Satellite Overhead
Channel # 1 Timeslot Selection
Channel # 1 Plesiochronous Buffer Sizes
Channel # 1 Buffer Clock Reference
User Channel # 2 ADPCM Audio Channel
Channel # 3 and # 4 Data Interface (Synchronous
mode)
Channel # 3 and # 4 Data Interface
(Asynchronous mode)
Channel # 3 and # 4 Clock Output
A–82
Table A-25. Demultiplexer Specific Specifications
Demultiplexer Specific Specifications
E1 Data Rates (N x 64 kbit/s)
N = 1 through 6, 8, 10, 12, 15, 16, 20, 24 or 30 (E1_CCS)
N = 1, 2, 4, 6, 8, 12, 16, 24, 30 (E1_CAS)
E1 (2048 kbit/s)
T1 Data Rates
N = 1 through 6, 8, 10, 12, 15, 16, 20 or 24 (T1)
(add 9 or 18 for T1, using special IBS superframe)
T1 (1544 kbit/s)
G.732, G.733 and G.704
16/15 of data rate per IESS-308, Rev. 6 and IESS-309, Rev. 3.
Applies when only Channel # 1 is selected, all other channels are "disabled".
1 to 24 (All T1 modes)
1 to 15, 17 to 31 (E1_CAS and E1_CCS)
1 to 31 (E1_31TS)(Slot 16 available)
Arbitrary order, non-contiguous available.
7.5, 15 and 30 ms (E1_CAS)
1, 2, 4, 8, 16 and 32 ms (E1_CCS)
6, 12, 24 and 32 ms (T1_S and T1_ESF_S)
1, 2, 4, 8, 16 and 32 ms (all other modes)
Driven from Insert Data In (Insert Clock)
Receive Satellite Clock
External Clock
SCT from Modulator
32 kbit/s audio channel 600Ω, balanced 4-wire.
The demultiplexer supports synchronous data for each tributary. The tributary
interfaces use DCE conventions with data (Receive data) and clock (Receive
clock) sourced by the demultiplexer.
The demultiplexer supports asynchronous data interface for each tributary. The
tributary data interface used (DCE) conventions with data (Receive data)
sourced by demultiplexer. Asynchronous mode at the demultiplexer is really no
different from synchronous mode, because the multiplex equipment does Async
to sync conversion prior to transmission over the satellite channel. The
asynchronous data is passed in a virtual transparent mode and retains the same
framing and formatting including start/stop and parity as the transmitting
equipment.
50% duty clock ± 10%, clock (Receive Timing) is phase locked to aggregate
clock recovered by the modem.
SDM-300A Satellite Modem
Rev. 4
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