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Shannon–Fano coding. In the field of data compression, Shannon–Fano coding, named after Claude Shannon and Robert Fano, is one of two related techniques for constructing a prefix code based on a set of symbols and their probabilities (estimated or measured). Shannon's method chooses a prefix code where a source symbol. i {\displaystyle i}
The encoding/decoding model of communication emerged in rough and general form in 1948 in Claude E. Shannon 's "A Mathematical Theory of Communication," where it was part of a technical schema for designating the technological encoding of signals. Gradually, it was adapted by communications scholars, most notably Wilbur Schramm, in the 1950s ...
After line coding, the signal is put through a physical communication channel, either a transmission medium or data storage medium. [3] [4] The most common physical channels are: the line-coded signal can directly be put on a transmission line, in the form of variations of the voltage or current (often using differential signaling).
Cryptography or cryptographic coding is the practice and study of techniques for secure communication in the presence of third parties (called adversaries). [8] More generally, it is about constructing and analyzing protocols that block adversaries; [ 9 ] various aspects in information security such as data confidentiality , data integrity ...
Data compression. In information theory, data compression, source coding, [1] or bit-rate reduction is the process of encoding information using fewer bits than the original representation. [2] Any particular compression is either lossy or lossless. Lossless compression reduces bits by identifying and eliminating statistical redundancy.
Delay-tolerant networking. Delay-tolerant networking (DTN) is an approach to computer network architecture that seeks to address the technical issues in heterogeneous networks that may lack continuous network connectivity. Examples of such networks are those operating in mobile or extreme terrestrial environments, or planned networks in space.
Differential Manchester encoding (DM) is a line code in digital frequency modulation in which data and clock signals are combined to form a single two-level self- synchronizing data stream. Each data bit is encoded by a presence or absence of signal level transition in the middle of the bit period, followed by the mandatory level transition at ...
Entropy coding. In information theory, an entropy coding (or entropy encoding) is any lossless data compression method that attempts to approach the lower bound declared by Shannon's source coding theorem, which states that any lossless data compression method must have an expected code length greater than or equal to the entropy of the source.