When Ethernet needs to be expanded to add a new medium or capability, the IEEE issues a new supplement to the 802.3 standard. The new supplements are given a one or two letter designation such as 802.3u. An abbreviated description (called an identifier) is also assigned to the supplement.

The abbreviated description consists of:

• A number indicating the number of Mbps transmitted.
• The word base, indicating that baseband signaling is used.
• One or more letters of the alphabet indicating the type of medium used (F= fiber optical cable, T = copper unshielded twisted pair).

Ethernet relies on baseband signaling, which uses the entire bandwidth of the transmission medium. The data signal is transmitted directly over the transmission medium. In broadband signaling, not used by Ethernet, the data signal is never placed directly on the transmission medium. An analog signal (carrier signal) is modulated by the data signal and the modulated carrier signal is transmitted. Radio broadcasts and cable TV use broadband signaling.

The IEEE cannot force manufacturers of networking equipment to fully comply with all the particulars of any standard. The IEEE hopes to achieve the following:

• Supply the engineering information necessary to build devices that comply with Ethernet standards.
• Promote innovation by manufacturers.

Interactive Media Activity Drag and Drop: IEEE 802 Standards This activity tests familiarity with all the IEEE 802 Standards.

Web Links IEEE 802 Committee Standards http://www.usyd.edu.au/is/comms/ networkcourse/ USydNet_mod1_ introduction&osimodel.html#tocIEEE