|
Category 1 Cable
Category 1 cable, also known as Cat 1, Level 1, or voice-grade copper, is a grade of unshielded twisted pair cabling designed for telephone A telephone, colloquially referred to as a phone, is a telecommunications device that enables two or more users to conduct a conversation when they are too far apart to be easily heard directly. A telephone converts sound, typically and most ... communications, and at one time was the most common on-premises wiring. The maximum frequency suitable for transmission over Cat 1 cable is 1 MHz, but Cat 1 is not currently considered adequate for data transmission (though it was at one time used for that purpose on the Apple Macintosh starting in the late 1980s in the form of Farallon Computing's//NetTopia's PhoneNet, an implementation of Apple's LocalTalk networking hardware standard). Although not an official category standard established by TIA/EIA, Category 1 has become the de facto name given to Le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unshielded Twisted Pair
Twisted pair cabling is a type of communications cable in which two conductors of a single Electronic circuit, circuit are twisted together for the purposes of improving electromagnetic compatibility. Compared to a Single-ended signaling, single conductor or an untwisted balanced pair, a twisted pair reduces electromagnetic radiation from the pair and crosstalk between neighboring pairs and improves rejection of external electromagnetic interference. It was invented by Alexander Graham Bell. For additional noise immunity, twisted-pair cabling may be Shielded cable, shielded. Cable with shielding is known as shielded twisted pair (STP) and without as unshielded twisted pair (UTP). Explanation A twisted pair can be used as a balanced line, which as part of a balanced circuit can greatly reduce the effect of noise currents induced on the line by coupling of electric or magnetic fields. The idea is that the currents induced in each of the two wires are very nearly equal. The twis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephone
A telephone, colloquially referred to as a phone, is a telecommunications device that enables two or more users to conduct a conversation when they are too far apart to be easily heard directly. A telephone converts sound, typically and most efficiently the human voice, into electronic signals that are transmitted via Electrical cable, cables and other communication channels to another telephone which reproduces the sound to the receiving user. The term is derived from and (, ''voice''), together meaning ''distant voice''. In 1876, Alexander Graham Bell was the first to be granted a United States patent for a device that produced clearly intelligible replication of the human voice at a second device. This instrument was further developed by many others, and became rapidly indispensable in business, government, and in households. The essential elements of a telephone are a microphone (''transmitter'') to speak into and an earphone (''receiver'') which reproduces the voice a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
On-premises Wiring
On-premises wiring (customer premises wiring) is customer-owned transmission or distribution lines. The transmission lines may be metallic (copper) or optical fiber, and may be installed within or between buildings. Premises wiring may consist of horizontal wiring, vertical wiring, and backbone cabling. It may extend from the point-of-entry to user work areas. Any type of telecommunications or data wiring is considered premises wiring, including telephone, computer/data, intercom, closed-circuit television. Premises networks are wired worldwide, across every industry, in both small and large-scale applications. Any type or number of topologies may be used – star, bus, ring, etc. In 1989, the United States Federal Communications Commission (FCC) deregulated charges for maintaining at home ''inside wiring''; the corresponding monthly charge was dropped January 1990. Ownership The ownership of on-premises wiring varies between jurisdictions: It depends on the location o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
McGraw Hill
McGraw Hill is an American education science company that provides educational content, software, and services for students and educators across various levels—from K-12 to higher education and professional settings. They produce textbooks, digital learning tools, and adaptive technology to enhance learning experiences and outcomes. It is one of the "big three" educational publishers along with Houghton Mifflin Harcourt and Pearson Education. McGraw Hill also publishes reference and trade publications for the medical, business, and engineering professions. Formerly a division of The McGraw Hill Companies (later renamed McGraw Hill Financial, now S&P Global), McGraw Hill Education was divested and acquired by Apollo Global Management in March 2013 for $2.4 billion in cash. McGraw Hill was sold in 2021 to Platinum Equity for $4.5 billion. History McGraw Hill was founded in 1888, when James H. McGraw, co-founder of McGraw Hill, purchased the ''American Journal of Railwa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apple Macintosh
Mac is a brand of personal computers designed and marketed by Apple Inc., Apple since 1984. The name is short for Macintosh (its official name until 1999), a reference to the McIntosh (apple), McIntosh apple. The current product lineup includes the MacBook Air and MacBook Pro laptops, and the iMac, Mac Mini, Mac Studio, and Mac Pro desktops. Macs are currently sold with Apple's UNIX-based macOS operating system, which is Proprietary software, not licensed to other manufacturers and exclusively Pre-installed software, bundled with Mac computers. This operating system replaced Apple's original Macintosh operating system, which has variously been named System, Mac OS, and Classic Mac OS. Jef Raskin conceived the Macintosh project in 1979, which was usurped and redefined by Apple co-founder Steve Jobs in 1981. The original Macintosh 128K, Macintosh was launched in January 1984, after Apple's 1984 (advertisement), "1984" advertisement during Super Bowl XVIII. A series of increment ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Farallon Computing
Netopia, Inc., formerly Farallon Computing, Inc., was an American computer networking company that produced a wide variety of products including bridges, repeaters and switches, and in their later Netopia incarnation, modems, routers, gateways, and Wi-Fi devices. The company also produced the NBBS (Netopia Broadband Server Software) and, as Farallon, Timbuktu remote administration software, as well as the MacRecorder, the first audio capture and manipulation products for the Macintosh (later sold to Macromedia). Farallon originated several notable technologies, including: * PhoneNet, an implementation of AppleTalk over plain ("Cat-3") telephone wiring or, more commonly, EIA-TIA 568A/B structured cabling systems. Many versions of the product were produced, but the original product was a commercialized version of a kit developed and produced by BMUG, the Berkeley Macintosh Users Group in 1986. * The StarController, a line of LocalTalk and Ethernet bridges and switches released ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anixter International
Anixter International Inc. is a company based in Glenview, Illinois, United States and founded in 1957. The company supplies goods and services for communications, security, networking, audio-visual, and industrial control applications. The company operates with three major divisions: Network & Security Solutions, Electrical and Electronic Solutions, and Utility Power Solutions. Aerospace Hardware, once considered the fourth division, was sold by Anixter in 2011 to Greenbriar Equity, which formed Align Aerospace. In 2002 Anixter was named as a Forbes "Platinum 400" company. On January 13, 2020, Anixter agreed to be acquired by WESCO International for $4.5 billion in cash and WESCO stock. Anixter's shares ceased trading as of June 22, 2020. History Anixter was started in 1956 by brothers Alan and Bill Anixter. Known originally as Anixter Brothers, the two opened Anixter as a wholesale distribution company that resold cable. The two brothers received a $20,000 loan from their ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TIA/EIA-568
ANSI/TIA-568 is a technical standard for commercial building cabling for telecommunications products and services. The title of the standard is ''Commercial Building Telecommunications Cabling Standard'' and is published by the Telecommunications Industry Association (TIA), a body accredited by the American National Standards Institute (ANSI). , the revision status of the standard is ''ANSI/TIA-568-E'', published 2020, which replaced ANSI/TIA-568-D of 2015, revision C of 2009, revision B of 2001, and revision A of 1995, and the initial issue of 1991, which are now obsolete. Perhaps the best-known features of ANSI/TIA-568 are the pin and pair assignments for eight-conductor 100-ohm balanced twisted pair cabling. These assignments are named ''T568A'' and ''T568B''. History ANSI/TIA-568 was developed through the efforts of more than 60 contributing organizations including manufacturers, end-users, and consultants. Work on the standard began with the Electronic Industries Alliance (EI ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Category 3 Cable
Category 3 cable, commonly known as or station wire, and less commonly known as VG or voice-grade (as, for example, in 100BaseVG), is an unshielded twisted pair (UTP) cable used in telephone wiring. It is part of a family of standards defined jointly by the Electronic Industries Alliance (EIA) and the Telecommunications Industry Association (TIA) and published in TIA/EIA-568-B. Although designed to reliably carry data up to , modern data networks run at much higher speeds, and or better cable is generally used for new installations. Cat 3 cables may have 2, 3, 4, or more pairs. Networking was widely used in computer networking in the early 1990s for 10BASE-T Ethernet and, to a much lesser extent, for 100BaseVG Ethernet, Token Ring and 100BASE-T4. The original Power over Ethernet 802.3af specification supports the use of cable, but the later 802.3at Type 2 high-power variation does not.IEEE 802.3at-2009, clause 33.1.1c In some use cases and for short distances, Cat 3 may ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signal Cables
Telecommunications cable is a type of guided transmission medium. Telecommunications are based on transmitting and receiving modulated waves/signals through a medium. Types of telecommunications cable include: electrical cables when electric current is carried; transmission lines and waveguides when electromagnetic waves are transmitted; optical fibers when light signals are transmitted. When the distances involved are very short, the term ''signal cable'' may be used, for analog or digital communication. A ''data cable'' is used in digital data communications. Data cabling must conform to certain standards and best practices to ensure reliable performance and safety. When the distance between the transmitter and receiver is very far, an unguided or wireless medium transmission may be used, based on antennas. Examples include: * Ethernet cables ( Cat 5, Cat 5e, Cat 6, Cat 6A) * Token Ring cables ( Cat 4) * Coaxial cable mainly used for analog communication, sometimes used as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
