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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The purpose of the analog tract in the receiver is to convert signal’s frequency, to adjust its power via an automatic gain control circuit and to get its complex envelope components. Similarly, a signal received from a satellite is firstly downconverted this is done by a Low-noise block converter – LNBthen demodulated by a modem, and at last handled by data terminal equipment. 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.

Then its frequency is converted if needed.

Scramblers and descramblers are usually based on linear-feedback shift registers. Articles lacking sources from October All articles lacking sources.

Washington Technology

Other equipment that are essential for creating a satellite link include satellite antennas and frequency converters. Moreover, it is possible to develop a demodulator which can process signals with different modulation types. A modulator is generally a much simpler device than a demodulator, because it doesn’t have to recover symbol and carrier frequencies. List of communications satellite firsts List of communication satellite companies. A FEC decoder decodes the Forward error correction code that is used in the specific signal.

They are appropriate only when certain conditions apply: Moddm communication standards also define error correction codes and framing formats. Information Throughput Adaptation ITA is a way to keep that built-in safety margin, but use it mdem enhanced data throughput when that margin is not needed. Unsourced material may be challenged and removed. 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 with other similar network devices.

The bottom line advantage of the MD efficiency is that more carriers can be placed on a single satellite transponder and those carriers can be better utilized, enabling more warfighters to gain access to more data when and where they need it.


Then the signal is either sampled or processed by the four-quadrant multiplier which produces the complex envelope components I, Q through multiplying it by the heterodyne frequency.

For well-groomed transponders, PCMA can be of value, but to a lesser degree.

However within common networks, interoperability with efficiency is the goal. There are several modulation types such as PSK and QAM that have a phase ambiguity, that is, a carrier can be restored in different ways. Interoperability and an open-standard approach has great advantages, but those responsible for military SATCOM still need to be sure eem choose the hardware that delivers the biggest and most efficient data pipe to the warfighter in the field.

Error correction works by adding an artificial redundancy to a data stream at the transmitting side, and using this redundancy to correct errors caused by noise and interference. However, the fundamental concepts are similar. The input signal for the analog tract is at the intermediate frequency or in the L-bandin the second case it must be firstly converted to IF.

The objective is to field fewer types of wireless network devices, while providing improved network interoperability to accommodate the emergence of Internet Protocol IP as a connectivity standard. Together, the features maximize overall network throughput across the satellite link when little or no margin is needed. After a digital-to-analog conversion in the transmitter the signal passes through a reconstruction filter. Generally, a demultiplexer is a device which transforms one multiplexed data stream to several streams which it consists of.

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 commercial technology.

Please help improve this article by adding citations modsm reliable sources. The primary additions to the new standard include government approved TRANSECadvanced modulation and forward error correction techniques, and enhancements specific to IP network-centric operation. There are also additional components in ebfm demodulator such as the Intersymbol interference equalizer.

This page was last mocem on 24 Octoberat 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. While most satellite transmissions require separate frequencies to transmit and receive, ViaSat PCMA technology enables one simplex carrier to be superimposed on another carrier, potentially decreasing the bandwidth required by as much as 50 percent.



A modulated signal is a sequence of symbolspieces of data represented by a corresponding signal state, e. In traditional fixed-channel military satellite communication environments, where a dB link margin is typical, these features can provide more than a percent improvement in data throughput.

At the same time, the Department of Defense wants to eebem to encourage innovation. A satellite modem is not the only device needed to establish a communication channel. The primary additions to the midem standard include government approved TRANSEC, advanced modulation and forward error correction techniques, and enhancements specific to IP network-centric operation.

Satellite modem – Wikipedia

Using different modems that have an open-standard waveform, but proprietary baseband interfaces is just as ineffective as using two different proprietary modems.

The ESEM module, used in conjunction with Information Throughput Adaptation, ramps up the satellite link data rate, and then a feature called Radio Aware Routing advertises that throughput potential to a network router. Scrambling is a technique used to randomize a data stream to eliminate long ‘0’-only and ‘1’-only sequences and to assure energy dispersal. Increased symbol rates to 60 Msps providing single carrier data rates up to Mbps.

Link budget analysis can determine feasibility, link configuration, and the possible overall savings of power and bandwidth with PCMA.

Satellite modem

High-end modems also incorporate some additional features:. At last the signal passes through an anti-aliasing filter and sampled digitized.

This module provides a basis for Ethernet interface interoperability amongst satellite modem vendors. Probably the best way of understanding modem’s work is to look at its internal structure. Demonstrations of the modem have shown the value of the new modulation moddm coding choices.