October 9, 2020

Enhanced Bandwidth Efficient Modem. (EBEM) Cryptographic Module. Non- Proprietary Security Policy. Document Number , Rev. ViaSat will provide the Army with MD(U) strategic EBEM and This modem uses advanced modulation and coding technology to. ViaSat Inc. (Nasdaq:VSAT) demonstrated its DISA certified MD Enhanced Bandwidth Efficient Modem (EBEM) to members of the U.S.

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A digital modulator transforms a digital stream into a radio signal on Intermediate frequency IF.

Information Throughput Adaptation ITA is a way to keep that built-in ebeem margin, but use it for enhanced data throughput when that margin is not needed.

Sometimes a digital automatic gain control circuit is implemented in the demodulator. Scrambling is a technique used to randomize a data stream to modrm long ‘0’-only and ‘1’-only sequences and to assure energy dispersal. The technology uses an adaptive self-interference cancellation technique to subtract the transmitted signal and recover the desired signal. Moxem most cases frequency has to be converted using an upconverter before amplification and transmission.

Then its frequency is converted if needed. From Wikipedia, the free encyclopedia. Generally, a demultiplexer is a device which transforms one multiplexed data stream to several streams which it consists of. Satellite modem doesn’t have so many outputs, so a demultiplexer here performs a drop operation, allowing to choose channels that will be transferred to output. Link budget analysis can determine feasibility, link configuration, and the possible overall savings of power and bandwidth with PCMA.

The purpose of the analog tract in the receiver is to convert signal’s frequency, mldem adjust its power via an automatic gain control circuit and to get its complex envelope components. Recovering a symbol clock making a local symbol moxem generator synchronous with the remote one is one of the most important tasks of a demodulator. A FEC decoder decodes the Forward error correction code that is used in the specific signal.

Satellite modem

Digital demodulation implies that a symbol clock and, in most cases, an intermediate frequency generator at the receiving side have to be synchronous with those at the transmitting side. This is often referred to as ‘Muxing. However, the fundamental concepts are similar. This is achieved by the following two circuits:. A modulator is generally a much simpler device than a demodulator, because it doesn’t have to recover symbol and carrier frequencies.


Scrambling shouldn’t be confused with encryption, since it doesn’t protect information from intruders. There are some devices that include only a demodulator and no modulator, thus only allowing data to be downloaded by satellite that are also referred to as “satellite modems. Unsourced material may be challenged and removed.

Articles lacking sources from October All articles lacking sources. Satellite communication standards also define error correction codes and framing formats.


Retrieved from ” https: Department of Defense telecommunication transmission policy is to simplify its integrated wireless networks. If the analog signal was digitized without a four-quadrant multiplier, the complex envelope has to be calculated by a digital complex mixer.

Almost all parts are optional. Moreover, it is possible to develop a demodulator which can process signals with different modulation types. Interoperability and an open-standard approach has great advantages, but those responsible for military SATCOM still need to be sure they choose the hardware that delivers the biggest and most efficient data pipe to the warfighter in the field. Mpdem Read Edit View history. This article does not cite any sources. If downlink power decreases, ITA then automatically and dynamically decreases the link data rate using more robust waveforms to maintain the link connection.

Other equipment that are essential for creating a satellite link include satellite antennas and frequency converters. Interoperability does not mean that SATCOM users should be faced with only a plain vanilla set of choices for their networking, rather that those choices should meet an underlying ability to interoperate eem other similar network devices. Demonstrations of the modem have moden the value of the new modulation and coding choices.


A multiplexer transforms several digital streams into one stream. During a demonstration, the EBEM has shown its seamless, error-free adaptation to data rates from 28 to over Mbps without operator intervention. Together, the features maximize overall network throughput across the satellite link when little or no margin is needed. A demodulator is one of the most important parts of the receiver.

There are also additional components in the demodulator such as the Intersymbol interference equalizer. This module provides a basis for Ethernet interface interoperability amongst satellite modem vendors.

At the same time, the Department of Defense wants to continue to encourage innovation. Differential coding is used to resolve this ambiguity.

At last the signal passes through an anti-aliasing filter and sampled digitized. A descrambler restores the original stream from the scrambled one. moddem

By using this site, you agree to the Terms of Use and Privacy Policy. There are also industrial satellite modems intended to provide a permanent link. Scramblers and descramblers are usually based on linear-feedback shift registers.

Providing an open standard for this enhanced forward error correction technique means that efficiency and interoperability can finally coexist. These new capabilities enable you to manage your communications resources and choose whether you maximize data throughput, enable more users to access the network, or decrease networking costs.

Though this new standard is often thought of as catching the military up to commercial standards and technology, the new B standard is actually enhanced beyond pure omdem technology.

Washington Technology

Satellite broadcasting Modems Telecommunications equipment Telecommunications infrastructure. Egem turbo codes at reasonable block size and complexity can come quite close to the Shannon channel capacity limit within about 1 to 2 dB. When differential coding is used, the data are deliberately made to depend not only on the current symbolbut also on the previous one.