A transmission medium is any material substance, such as fiber-optic cable, twisted-wire pair, coaxial cable, dielectric-slab waveguide, water, or air, that can be used for the propagation of signals, usually in the form of modulated radio, light, or acoustic waves, from one point to another. Fiber Optic strands An optical fiber in American English or fibre in British English is a transparent thin fiber for transmitting light. ... Coaxial cable is an electrical cable consisting of a round conducting wire, surrounded by an insulating spacer, surrounded by a cylindrical conducting sheath, and usually surrounded by a final insulating layer. ... The electrons in the molecules shift toward the positively charged left plate. ... In physics, optics, and telecommunication, a waveguide is a structure that confines and guides a propagating electromagnetic wave. ... The word propagation can mean: Multiplication or increase, as by natural reproduction. ... Prism splitting light Light is electromagnetic radiation with a wavelength that is visible to the eye, or in a more general sense, any electromagnetic radiation in the range from infrared to ultraviolet. ...

Coaxial Cable, one example of a transmission medium

Note: By extension, free space can also be considered a transmission medium for electromagnetic waves, although it is not a material medium. Photo of RG-59 cable, taken and annotated by Heron 20:15, 6 Oct 2004 (UTC). ... Photo of RG-59 cable, taken and annotated by Heron 20:15, 6 Oct 2004 (UTC). ... Coaxial cable is an electrical cable consisting of a round conducting wire, surrounded by an insulating spacer, surrounded by a cylindrical conducting sheath, and usually surrounded by a final insulating layer. ... In physics, free space is a concept of electromagnetic theory, corresponding roughly to the vacuum, the baseline state of the electromagnetic field, or the replacement for the electromagnetic aether. ... In communications, transmission is the act of transmitting electrical messages (and the associated phenonomena of radiant energy that pass through media). ... The word medium has a number of uses:ukahsbd The most common meaning of the word medium is an average or mean in a range of sizes or conditions. ...

Source: From Federal Standard 1037C Federal Standard 1037C entitled Telecommunications: Glossary of Telecommunication Terms is a U.S. Federal Standard, issued by the General Services Administration pursuant to the Federal Property and Administrative Services Act of 1949, as amended. ...

Transmission media can be classified in two kinds: guided (or bounded) media in which waves are guided along a solid medium, and wireless (or unguided) media in which transmissions and receptions are achieved by means of an antenna.

See also

• Communications
• Physical layer