Twisted-pair wire
Characteristics, advantages, disadvantages, Differences between Category 1, 2, 3, 4, 5, 5e, 6, and 7.
Shielded vs Unshielded twisted pair wire
Coaxial cable & Fiber-Optic cable
Microwave systems
Terrestrial & Microwave
Basics of cellular telephones
Short-range transmission technologies (Bluetooth)
Characteristics, advantages, and disadvantages of:
Wireless Application Protocol (WAP),
Broadband wireless systems, and
Various wireless local area network transmission techniques
The world of computer networks would not exist if there were no medium by which to transfer data
The two major categories of media include:
Conducted media
Wireless media
One or more pairs of single conductor wires that have been twisted around each other
Twisted pair wire is classified by category.
Currently Category 1 through Category 7
Categories 1, 2 and 4 are nearly obsolete
Twisting the wires helps to eliminate electromagnetic interference between the two wires
Shielding can further help to eliminate interference
Media selection criteria of cost, speed, right-of-way, expandability and distance, environment, and security to various media in a particular application
A single wire surrounded by a braided shield
Because of shielding, can carry a wide bandwidth of frequencies
Thus is good with applications such as cable television
Not as easy to install as twisted pair
More expensive than twisted pair
Land-based, line-of-sight transmission
Approximately 20-30 miles between towers
Transmits data at hundreds of millions of bits per second
Signals will not pass through solid objects
Popular with telephone companies and business to business transmissions
Fiber optic cable can carry the highest data rate for the longest distances
Initial cost-wise, more expensive than twisted pair, but less than coaxial cable
But when you consider the superiority of fiber, initial costs outweighed by capacities
Need to fibers for a round-trip connection not affected by electromagnetic noise and cannot be easily wiretapped, but still noise
Several basic groups of wireless media exist: terrestrial microwave transmissions, satellite transmissions, cellular telephone systems, infrared transmissions, WiMAX,
Bluetooth, Wi-Fi, free space optics, ultra-wideband, near-field communications, and ZigBee
Each of the wireless technologies is designed for specific applications
When trying to select particular medium for an application, it helps to compare the different media using these six criteria: cost, speed, expandability and distance, right-of-way, environment, and security.
