Premier Mounts CDM-600 specifications Standard Features, Aupc

CDM-600 Satellite Modem	Revision 7
Introduction	MN/CDM600.IOM

1.1Standard Features

The CDM-600 provides a wealth of standard features which go far beyond the basic requirements of the Intelsat specifications.

•Low rate variable data rates – 2.4 kbps to 5.0 Mbps

•Mid-rate variable data rates – 2.4 kbps to 10.0 Mbps

•High-rate variable data rates – 2.4 kbps to 20.0 Mbps

•Embedded Distant-end Monitor and Control (EDMAC) (see Note)

•Selectable 50Ω / 75Ω IF port impedance

•Asymmetric Loop Timing

•Automatic Uplink Power Control (AUPC)

•Software – Flash Upgrading

•Modulation Types –BPSK, QPSK, and OQPSK

•1:1 and 1:10 redundancy switches

Note: In this mode, an additional 5% overhead is combined with the traffic data,

(1.5% in Turbo BPSK modes, Turbo Rate 1/2 QPSK/OQPSK, and all data rates greater than 2 Mbps) which permits Monitor & Control (M&C) information to be added (transparently to the user), allowing access to the distant-end modem. This mode does not require any additional cabling at either the local or distant-end Modems - access to EDMAC is via the standard M&C control port. Full M&C is possible, and importantly, the on/off status of the carrier at the distant-end carrier can be controlled. In addition, for firmware version 1.5.0 and higher, the proprietary D&I++ framing mode is available. This combines Drop & Insert (D&I) operation with a similar EDMAC link and a 2.2% overhead.

1.1.1AUPC

An important innovation in the CDM-600 is the addition of Automatic Uplink Power Control (AUPC). This feature enables the modem to automatically adjust its output power to maintain the Eb/No of the remote end of the satellite link constant. This provides protection against rain fading, a particularly severe problem with Ku-band links.

To accomplish this, either the EDMAC or D&I++ framing types may be used, and the distant end modem constantly sends back information about the demodulator Eb/No using reserved bytes in the overhead structure. Using the Eb/No, the local modem then adjusts its output power, and hence, a closed-loop feedback system is created over the satellite link.

A benefit of this feature is that whenever EDMAC or D&I++ with AUPC operation is selected, the remote demodulator’s Eb/No can be viewed from the front panel display of the local modem. Note that EDMAC and D&I++ can be used in conjunction with either framing type.

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