Comtech EF Data CDM-570L L-Band satellite Modem

Overview
The CDM-750 Advanced High-Speed Trunking Modem was designed to be the most efficient, highest
throughput, point-to-point trunking modem available. The CDM-750 accommodates the most demanding
Internet Service Provider (ISP) and telco backhaul links by offering users the most advanced combination
of space segment saving capabilities while minimizing the need for unnecessary overhead. With the
ability to process packets at line speed, the CDM-750 will not throttle throughput due to
processing limitations. Beginning with the most efficient coding and modulation available, the CDM-750
leverages the DVB-S2 EN 302 307 LDPC/BCH standard to provide the best possible combination of
coding and forward error correction ensuring that the maximum amount of satellite traffic is transported for
a given signal to noise capacity.
Implementing Adaptive Coding and Modulation (ACM) operation (in packet-based applications) allows link
margin to be converted to user capacity during non-faded conditions by taking advantage of the actual
signal to noise ratio rather than calculated worst case signal to noise. This technology transforms link
margin, implementation margin and margin for antenna pointing directly to improved throughput.

Typical Users

• Mobile Operators
• Telecom Operators
• ISPs
• Government & Military

Common Applications

• IP Trunking
• G.703 Trunking
• High-Speed Content
Delivery
• Disaster Recovery &
Emergency
Communications

By using the best encapsulation methods, the CDM-750 further increases throughput by using minimal
overhead. In G.703 synchronous mode, users can implement monitor and control over the satellite with
no additional overhead. When using Ethernet bridge mode, less than 1% overhead is used for
encapsulation.
The optional K4 GZIP lossless compression engine performs real-time compression of Ethernet traffic and
is capable of running at the full rate of the modem. Offering 52% to 59% compression rates at random
packet sizes using the Calgary Corpos bitstream, K4 GZIP can greatly increase the throughput of the
satellite link, or reduce required bandwidth.
Additionally, the CDM-750 leverages Comtech EF Data’s powerful DoubleTalk® Carrier-in-Carrier®
“Adaptive Cancellation” technology. With the ability to overlay TX and RX carriers, Carrier-in-Carrier
enables the operator to establish the perfect balance between bandwidth and power, enabling the best
possible use of the satellite resource and reducing operating expenses (OPEX).
These technologies alone offer enormous savings to the ISP and telco operator. When used in
combination, however, the savings are astronomical. The innovative high-performance architecture of the
CDM-750 allows efficient networking and transport over satellite links while supporting a wide range of
applications and network topologies.

Features