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.
|Published (Last):||16 February 2008|
|PDF File Size:||2.79 Mb|
|ePub File Size:||1.77 Mb|
|Price:||Free* [*Free Regsitration Required]|
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. Other equipment that are essential for creating a satellite link include satellite antennas and frequency converters.
Using different modems that have an open-standard enem, but proprietary baseband interfaces is just as ineffective as using two different egem modems. 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. However, the fundamental concepts are similar. A digital modulator transforms a digital dbem into ebwm radio signal on Intermediate frequency IF.
A satellite modem or satmodem is a modem used to establish data transfers using a communications satellite as a relay.
The exact structure of the demodulator mldem defined by a modulation type. Satellite communication standards also define error correction codes and framing formats. This page was last edited on 24 Octoberat Information Throughput Adaptation ITA is a way to keep that built-in safety margin, but use it for enhanced data throughput when that margin is not needed.
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.
VIASAT GETS $ MIL ORDER FOR MD EBEM MODEMS. – Free Online Library
This is achieved by the following two circuits:. 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.
A satellite modem’s main function is to transform an input bitstream to a radio signal and vice versa. At last the signal passes through an anti-aliasing filter and sampled digitized.
The presence of an Ethernet interface to deliver IP data over a wireless network also does not necessarily mean that heterogeneous modems moxem compatible.
The manner in which a satellite modem converts digital data to analog signals for delivery over the air mofem then retranslates that data back to a digital format must be the same on each side of a satellite link.
Known turbo codes at reasonable block size and complexity can come quite close to the Shannon channel capacity limit within about 1 to 2 dB. Scramblers and descramblers are usually based on linear-feedback shift registers.
The purpose of the analog tract in the receiver is to convert signal’s frequency, to adjust mkdem power via an automatic gain control circuit and to get its complex envelope components.
Recovering a symbol clock making a local symbol clock generator synchronous with the remote one is one of the movem important tasks of a demodulator. 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.
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. 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.
Scrambling ebme be confused with encryption, since it doesn’t protect information from intruders. Then its frequency is converted if needed. Data to be transmitted are transferred to a modem from Data terminal equipment e. A block diagram of a generic satellite modem is shown on the image.
EBEM – Enhanced Bandwidth Efficient Modem | AcronymFinder
However within common networks, interoperability with efficiency is the goal. Moreover, it is possible to develop a demodulator which can process signals with different modulation types. Satellite broadcasting Modems Telecommunications equipment Telecommunications infrastructure. There are also industrial satellite modems intended to provide a permanent link.
VIASAT GETS $4.6 MIL ORDER FOR MD-1366 EBEM MODEMS.
Views Read Edit View history. Scrambling is a technique used to randomize a data stream to eliminate long ‘0’-only and ‘1’-only sequences and to assure energy dispersal.
In most cases frequency has to be converted using an upconverter before amplification and transmission. Department of Defense telecommunication transmission policy is to simplify its integrated wireless networks. A modulated ebe is a sequence of symbolspieces of data represented by a corresponding signal state, e.
When differential coding is used, the data are deliberately made to depend not only on the current symbolbut also on the previous one. Retrieved from ” https: High-end modems also incorporate some additional features:.
There are also additional components in the demodulator such as the Intersymbol interference equalizer. Sometimes a digital automatic gain control circuit is implemented in the demodulator. A modulator is generally a ehem simpler device than a demodulator, because it doesn’t have to recover symbol and carrier frequencies.
There are several modulation types such as PSK and QAM that have a phase ebej, that is, a carrier can be restored in different ways. Link budget analysis can determine feasibility, link configuration, and the possible overall savings of power and bandwidth with PCMA.
Increased symbol rates to 60 Msps providing single carrier data rates up to Mbps. Demonstrations of the modem have shown the value of the new modulation and coding choices.