|−|==External links== |+|
|−|* [http://www. sarc-wv. com Steganography Analysis and Research Center] The Steganography Analysis and Research Center is a Center of Excellence within Backbone Security focused exclusively on steganography research and development of steganalysis products and services. |+|
|−|===Steganalysis Training=== |+|
|−|* [http://www.sarc-wv.com/training.aspx Steganography Examiner Training] |+|
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|−|===Algorithms and Tools=== |+|
|−|* [http://www. sarc-wv.com/safdb.aspx Steganography Application Fingerprint Database] A fundamental goal of the SARC is to collect steganography, watermarking, and other data-hiding applications from various sources and incorporate file profiles computed from them into the SAFDB. The SAFDB can be used to review files on seized media by matching file profiles in the SAFDB. SAFDB is the most extensive steganography hash set publicly available. The file profiles contain identifying information such as filename, associated application name, file size, and several unique hash values. These hash values may be used to determine the presence of a steganography application or artifact of a steganography application on the media being examined. The SAFDB is available for download in formats compatible with most of the popular digital forensic tools and utilities: EnCase, Forensic Toolkit (FTK), HashKeeper, ILook, and ProDiscover. |+|
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|−|* [http: //www. sarc-wv. com/stegalyzeras.aspx Steganography Analyzer Artifact Scanner (StegAlyzerAS)] StegAlyzerAS gives you the capability to scan the entire file system, or individual directories, on suspect media for the presence of steganography application artifacts. And, unlike other popular forensic tools, you can perform an automated or manual search of the Windows Registry to determine whether or not any Registry keys or values exist that can be associated with a particular steganography application. |+|
|−|* [http://www.sarc-wv.com/stegalyzerss.aspx Steganography Analyzer Signature Scanner ( StegAlyzerSS) ] StegAlyzerSS gives you the capability to scan every file on the suspect media for the presence of hexadecimal byte patterns, or signatures, of particular steganography applications in the files. If a known signature is detected, it may be possible to extract information hidden with the steganography application associated with the signature. |+|
|−|* [http:// www. sarc-wv. com/ stegalyzerrts.aspx Steganography Analyzer Real-Time Scanner (StegAlyzerRTS)] StegAlyzerRTS is the first commercially available network security appliance in the world capable of detecting the fingerprints and signatures of digital steganography applications in real-time. |+|
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Revision as of 03:01, 29 September 2006
TDMA - Time Division Multiple Access
TDMA (Time Division Multiple Access), has the largest network in the US.
TDMA is a digital wireless communication method allowing many users to access a single radio frequency without interference. Every individual user is given a unique time slot within each channel.
Why use TDMA? IT increases the efficiency of transmission and offers a number of other advantages. A major pro is it can be easily adapted to transmission of data as well as voice communication. It offers the ability to carry date rates of 64 kbps to 120 mbps, which enables options of communication such as fax, voiceband data, sms, as well as bandwidth intensive apps. TDMA allows the user to have extended battery life since the mobile is only transmitting a portion of the time during conversations. Furthermore, it is the most cost effective technology for upgrading a current analog system to digital.
How it works:
It’s necessary for TDMA to rely upon that fact that the audio signal has been digitized. These signals are divided into a number of milliseconds. TDMA is also the access technique used in the European digital standard, GSM, and the Japanese digital standard, personal digital cellular (PDC). The reason for choosing TDMA for all these standards was that it enables some vital features for system operation in an advanced cellular or PCS environment. Today, TDMA is an available, well-proven technique in commercial operation in many systems.
A single channel can carry all four conversations if each conversation is divided into relatively short fragments, is assigned a time slot, and is transmitted in synchronized timed.