Computer viruses have been around just about as long as the personal computer has existed. With the advent of the Internet, the ability of viruses to rapidly spread has increased substantially. Despite this increase in capability to infect large numbers of computers across international borders, the definition of a computer virus has not substantially changed …
A DBS, or Direct Broadcast Satellite, is a type of satellite that is used to broadcast data directly to a residence or commercial office, without the use of intermediary cables or other routing equipment. DBS systems are most commonly used for direct broadcast television and Internet access, in which users from anywhere in the world …
Hertz is the International System of Units (SI) base unit of measurement for frequency. Hz is the standard abbreviation for hertz. One hertz is defined as “one complete cycle per second,” and can be applied to any periodic event, but is usually applied to sound waves, electrical current, and radio waves. The hertz is the …
ICMP is the Internet Control Message Protocol. ICMP is a complementary protocol to IP (Internet Protocol). Like IP, ICMP resides on the Network Layer of the OSI Model. ICMP is designed for sending control and test messages across IP networks. Unlike the Transport Layer protocols TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) which …
A retrograde orbit is an orbit where the satellite travels in an East to West direction instead of the common West to East orbit. The normal West to East orbits are known as prograde orbits. Retrograde orbits are uncommon due to the much higher velocities necessary for successful launch and the associated higher costs. During …
Hard drive data recovery is the process of recovering lost data from a hard drive when the data cannot be readily accessed through normal retrieval methods. Whether the hard drive has locked up or has completely crashed, there is a good chance the data can be recovered with a variety of hard drive data recovering …
MCPC stands for Multiple Channel Per Carrier. MCPC is a form of satellite transmission where each carrier is utilized to transmit multiple channels. MCPC transmits multiple video or audio channels on one carrier by utilizing Time Division Multiplexing (TDM). The alternative to MCPC is SCPC (Single Channel Per Carrier). MCPC is used much more than …
ADSL Internet Access Asynchronous Digital Subscriber Line (ADSL) is a broadband Internet option that is commonly available in many locations. Asynchronous only means that the download speeds and the upload speeds are different (with the upload speeds usually being significantly lower) and provides a fast option to browse the web. Internet access through ADSL requires one …
The PSP (PayStation Portable) is a popular, hand-held gaming console that the Sony Corporation produced in 2004. The PSP was the first portable gaming device that used an optical disc format as the primary storage medium for its video games. The PSP is the primary competition for Nintendo DS and the updated version includes additional …
Pulse Code Modulation (PCM) was pioneered by the British engineer Alec Reeves in 1937. The first transmission of a message using PCM was the SIGSALY voice encryption equipment used in high-level Allied communications during World War II starting in 1943. The original primary application for PCM was to convert analog signals into digital format by …