1U:Abbreviation for "one unit""U"
= 1.75 inches. |
| 4B5B
Encoding: A signal modulation scheme
in which groups of four bits are encoded and
transmitted in five bits in order to guarantee
that no more than three consecutive zeroes ever
occur; used in FDDI. |
| 4:1:1: The set of sampling frequencies used to digitize
the luminance and color difference components
(Y, R-Y, B-Y) of a video signal. The four represents
13.5 MHz, the sampling frequency of Y, and the
ones each 3.75 MHz for R-Y and B-Y. |
| 4:2:0: A sampling system used to digitize the luminance
and color difference components (Y, R-Y, B-Y)
of a video signal. The four represents the 13.5
MHz sampling frequency of Y, while the R-Y and
B-Y are sampled at 6.75 MHz ?effectively
between every other line only (one line is sampled
at 4:0:0, luminance only, and the next at 4:2:2). |
| 4:2:2: A commonly used term for a component digital
video format. It is generally used as shorthand
for ITU-R 601. 4:2:2 is the
standard for digital studio equipment. |
 |
| 4fsc: Abbreviation for four times the frequency of
SC (subcarrier). The sampling rate of
a D2 digital video signal with respect to the
subcarrier frequency of a video signal. The
4fsc frequency is 14.3 MHz
in NTSC and 17.7 MHz in PAL. |
8B10B Encoding: A signal modulation scheme in which eight
bits are encoded in a 10-bit word to ensure
that too many consecutive zeroes do not occur;
used in ESCON and fibre channel. |
802.3 Network: A 10 Mb/s CSMA/CD bus-based network;
commonly called Ethernet. |
802.5 Network: A token-passing ring network operating
at 4 Mb/s or 16 Mb/s. |
10BASE-F: A fiber optic
version of an IEEE 802.3 network. |
| 10BASE-FB: That portion
of 10BASE-F that defines the requirements for
a fiber backbone. |
| 10BASE-FL: That portion
of 10BASE-F that defines a fiber optic link
between a concentrator and a station. |
| 10BASE-FP: That portion
of 10BASE-F that defines a passive star coupler. |
| 10BASE-T: A twisted-pair
cable version of an IEEE 802.3 network. |
| 10BASE-2: A thin-coaxial-cable
version of an IEEE 802.3 network |
| 10BASE-5: A thick-coaxial-cable
version of an IEEE 802.3 network; very similar
to the original Ethernet specification. |
