By Andy Zietlow PC Networking – Wiring and Fiber
Wires: • Wires are used for transmitting an electrical signal. Different kinds of cords, each specialized in their purpose, have different configurations of wires. • Types of signals: • Digital – Often represents continuous bit streams • Analog – A time-varied signal that is “analogous” to another time-varied variable • Wires can also carry nothing but electrical energy, rather than information streams
Wires • Solid • A solitary strand of metal • Extremely durable • Rubber Insulation limits the loss of net electrical impulse signaling
Wires • Stranded (also known as cables) • More flexible than solid wires of the same size • There is an overall loss of electrical impulses owing to the gaps between wires, making efficiency just slightly lower than solid wires.
Wires • Bare • Copper wire with no insulation on it. • This stranded, bare, annealed copper • conductors are recommended for use as • neutrals, in circuit ground connections as • well as machinery and equipment grounding • systems.
Networking Wires: • Twisted Pairs: • Invented by Alexander Graham Bell, the twisted pair configuration of wiring was made to cancel out interference (EMI) from external sources. The two wires must come from the same circuit. Each wire carries equal and opposite signals. • This table shows many different kinds of configurations
Networking Patch Cables: • Category 5 Twisted Pair: • A twisted pair cable for carrying signals. This type of cable is used in structured cabling for computer networks such as Ethernet. The cable standard provides performance of up to 100 MHz and is suitable for 10BASE-T, 100BASE-TX (Fast Ethernet), and 1000BASE-T (Gigabit Ethernet). Cat 5 is also used to carry other signals such as telephony and video.
Networking Wires: • Optical Fiber Cable • A cable containing one or more optical fibers. The optical fiber elements are usually individually coated with plastic layers and contained in a protective tube suitable for the environment where the cable will be deployed.
Wire history - Copper’s discovery can be placed as far back as 10,000 years ago, but its use for electrical wiring and conduction was not until the discovery of the electromagnet and telegraph in the early 1800s.In 1876, Alexander Graham Bell made extensive use of Copper Wiring in his inventions as a key electrical conductor due to its wide availability and great ductility. Since then, copper wire has been a staple in the telecommunication, electrical engineering, and power generation fields.
Wire Manufacturers: • Belden • Superior Essex • Nexans • The Okonite Company Pricing (per foot/meter) - $3 to $~50
How Fiber Optic Cables Work • The components of fiber optic cables: • Core – pure glass center which light travels through • Cladding – This layer is to improve reflection efficiency and minimize light escape from the cable • Buffer Coating – Like insulation to wires, this layer is mainly for protection
How Fiber Optic Cables Work • Fiber optic cables are composed of small bits of glass, fractured for flexibility, in a tube form to transmit signals over distances. • Efficiency is determined by distance the beam travels, the reflection quality of the glass, and the type of signal itself. • They are no larger than a single human hair
History of Fiber Optics It was not until the 1790s that the French Chappe brothers invented the first "optical telegraph,” a system comprised of a series of lights mounted on towers where operators would relay a message from one tower to the next. In 1970, the goal of making single mode fibers with attenuation less then 20dB/km was reached by scientists at Corning Glass Works. Sprint was founded on the first nationwide, 100 percent digital, fiber-optic network in the mid-1980s.
Types of Fiber Optic Cables • Multimode Fiber: • Multimode fiber is designed for short transmission distances, well-suited for use in LAN systems and video surveillance. • The first to be manufactured and commercialized, it simply refers to the fact that numerous modes or light rays are carried simultaneously through the waveguide. This fiber type has a much larger core diameter, compared to single-mode fiber, allowing for the larger number of modes, and multimode fiber is easier to couple than single-mode optical fiber.
Types of Fiber Optic Cables • Single-mode Fibers: • Single-mode fiber allows for a higher capacity to transmit information because it can retain the fidelity of each light pulse over longer distances, and it exhibits no dispersion caused by multiple modes. There are three types of Single-mode Fibers: • Non-dispersion shifted Fiber – These fibers were initially intended for use near 1310 nm wavelengths. • Dispersion-shifted Fiber – Used when 1550 nm wavelengths were made popular. • Non zero-dispersion-shifted fibers – Used to overcome DSF’s shortcoming when paired close together to other DSFs.
Manufacturures of Fiber Optics • HP • Cisco • Belkin • Mohawk Cables • Prices (per foot or meter) - $20 - $250
Sources: http://www.timbercon.com/history-of-fiber-optics/ http://en.wikipedia.org/wiki/Networking_cables http://en.wikipedia.org/wiki/Optical_fiber http://www.howstuffworks.com/fiber-optic.htm http://www.distributorwire.com/blog/index.php/knowledge-base/history-copper/