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2114 West 7th Street • Tempe, Arizona 85281 USA
Telephone 1.480.333.2200 • Fax 1.480.333.2540

Comtech EF Data Announces High Volume Production Availability Of The Next Generation Satellite Modem

Advanced, Flexible & Combines LDPC with DoubleTalk® Carrier-in-Carrier®

TEMPE, Arizona, May 19, 2008 – Comtech EF Data Corporation announced today its CDM-625 Advanced Satellite Modem is now in high volume production. The CDM-625 builds on Comtech EF Data’s tradition of providing bandwidth and power efficient satellite modems, and is the first modem to combine the Low Density Parity Check (LDPC) Forward Error Correction (FEC) with the DoubleTalk® Carrier-in-Carrier® bandwidth compression. This new platform is suited for mobile and telecommunications operators, satellite service providers, government and military entities, and enterprise users.

DoubleTalk Carrier-in-Carrier, based on the patented “Adaptive Cancellation” technology, allows the transmit and receive carriers of a duplex link to share the same transponder space. LDPC is an advanced FEC capable of providing performance much closer to the Shannon limit compared to any other technique. The combination of LDPC and DoubleTalk Carrier-in-Carrier can enable savings in transponder bandwidth and power utilization, as well as earth station BUC/HPA size.   

The CDM-625 includes a number of other advanced features. Supporting 70/140 MHz and L-Band capability in the same unit with independently selectable transmit and receive IF, it simplifies sparing and stocking in networks requiring both frequencies. It features data rates from 18 kbps to 25 Mbps and symbol rates of 18 ksps to 12.5 Msps. The unit supports Viterbi, Concatenated Reed Solomon, and TCM Forward Error Correction plus an integrated TPC and LDPC codec. Providing ultimate flexibility for diverse environments, the CDM-625 offers a wide range of data interfaces, including EIA‑422/530, V.35, G.703 T1, G.703 E1, G.703 T2, G.703 E2, Quad G.703 E1, ASI, LVDS, HSSI, and 4-port 10/100BaseT Ethernet for traffic bridging.

For telecommunications and high speed trunking applications, the CDM-625 supports a Quad E1 interface that can aggregate up to four full or fractional E1s into a single carrier with very low overhead, significantly reducing multi-carrier power backoff requirements. This allows users to reduce the number of modems required while simultaneously reducing their BUC/HPA power requirements.

The CDM-625 provides several options for local and remote management. The modem can be managed via the front panel, the remote monitor and control port or the 10/100BaseT Ethernet port.  With support for SNMP, http and Telnet, the modem can be easily integrated into an IP-based management system.

The CDM-625 is also backwards compatible with the CDM-600/L Satellite Modems. It even supports a CDM-600/L emulation mode that makes it easy to deploy in existing networks using CDM-600/L without changes to the 1:N redundancy switches or the management platform.

 "The addition of the CDM-625 to our modem product line is complementary to the CDM-Qx/L and
CDM-600/L Satellite Modems," said Daniel Enns, senior vice president strategic marketing and business development for Comtech EF Data. "The combination of advanced technologies in the CDM-625 will enable users to realize multi-dimensional optimization of their satellite links."

General Communication, Inc. (GCI) is a regional integrated communication provider serving the state of Alaska. The company invests in integrated communication assets to create value for customers, opportunities for employees and growth for shareholders. With a company culture of utilizing the latest technologies for their network infrastructure, GCI recently conducted performance testing of the CDM-625.

"We conducted extensive performance tests on the new CDM-625," said Jimmy Sipes, vice president network services for GCI. "Based on the advanced feature set, performance and the prospect of additional operating expense savings, we will begin immediate deployment of Comtech’s CDM-625 modems in our satellite network."

Comtech EF Data is now accepting orders for the CDM-625 Advanced Satellite Modem. Please visit for additional information and technical specifications.

About General Communication, Inc.
GCI is the largest telecommunications company in Alaska. A pioneer in bundled services, GCI provides local, wireless, and long distance telephone, cable television, Internet and data communication services throughout Alaska. More information about the company can be found at

About Comtech EF Data Corp.
Comtech EF Data Corp. manufactures a broad spectrum of satellite communications products, including Satellite Modems, Bandwidth & Capacity Management, TCP/IP Performance Enhancement Proxies, Encapsulators, Receivers, Converters, Amplifiers, Transceivers and Terminals.  All products meet or exceed the standards published by worldwide and regional satellite networks. Please visit for more information.


Media Contact:
Sue Wilcox
Comtech EF Data
Voice: 480.333.2200
Fax: 480.333.2540