In this section, we see how we can represent digital data by using digital signals. The conversion involves three techniques: line coding, block coding, and scrambling. Line coding is always needed; block coding and scrambling may or may not be needed.
With the development of computing technologies, digital media security becomes an ever
increasing issue of daily life. As computer software and hardware evolves and as more
of it becomes accessible as an Internet application or service, information security has
gone from initially protecting digital images, into the area of multimedia. This area of
multimedia includes computer graphics, images, digital video and digital audio. As the
Internet expands, so does the significance of multimedia security.
In the last two years, optical networking has risen into the public consciousness
in many different ways. It has become the next great technological
thing — businesses want it, service providers want to sell it, device
manufacturers want to provide equipment, and component manufacturers
are scrambling to supply pieces and parts to all of them. At the time of
this writing, an 18-month backlog on optical fiber and some optical amplifiers
exists because of the enormous and unanticipated demand for highbandwidth
Atlas DMT and Other Industry Leaders Prove the Effectiveness of Online Advertising
Online Advertising has been much maligned in recent months. Following the tumble of the NASDAQ, many in the industry are scrambling to prove the viability of their advertising-supported business models. Ironically, the Internet’s own accountability has been its downfall. Due to reports of declining click-through rates (CTR), banner advertising is suddenly the black-sheep marketing channel. The problem is that focusing on click-through rates misses the point of advertising.
Encryption is a widely used technique which involves
making information indecipherable to protect it from
unauthorised viewing or use, especially during
transmission or when it is held on removable magnetic
media. Encryption is usually based on a key(s)
without which the information cannot be decoded
(decrypted). The most widely used encryption system
is DES (Data Encryption Standard) although
increasingly this is being replaced commercially by
the more secure public key system RSA.