The satellite connection from the ground station to the satellite.
The portion of a communications link between a satellite and a ground
station in which data travels from the satellite down to the earth.
The time it take
Carrier sense multiple access collision detect. Media-access mechanism
wherein devices ready to transmit data first check the channel for a
carrier. If no carrier is sensed for a specific period of time, a device can
transmit. If two devices trans
Corporation for Research and Educational Networking. The result of a
merger of BITNET and CSNET. CREN is devoted to providing Internet
connectivity to its members, which include the alumni, students, faculty,
and other affiliates of participating edu
Count to Infinity
Problem that can occur in routing algorithms that are slow to converge,
in which routers continuously increment the hop count to particular
networks. Typically, some arbitrary hop-count limit is imposed to prevent
Cells per second.
Central Processing Unit. The main processor in the
computer'sconfiguration that handles processing tasks or directs
auxiliaryprocessors (coprocessors) to perform them.
A computing activity or network interaction whose s
In a packet-switched star topology, a router that is part of the backbone
and that serves as the single pipe through which all traffic from
peripheral networks must pass on its way to other peripheral networks.
1. Class of service. Indicat
In SNMP (Simple Network Management Protocol), a software program
that has the capability of interacting with an agent, including examining
or changing the values of the data objects in the agent's Management
Information Base (MIB).
In data networks, a type of computer relationship in which the network
equipment constructs a circuit between the two devices for the duration
of their relationship. Once the circuit is established, the devices pass
information back an
The physical link (such as wire or a telephone circuit) that connects one
or more devices to one or more other devices.
In SNMP, a logical group of managed devices and NMSs in the same
Geosynchronous-Earth-Orbit Satellites - GEO
Satellites that are found 22,300 miles from the earth and are always over
the same point on earth.
Highly Elliptical Orbit Satellites - HEO
A satellite that follows an elliptical pattern and is designed to perfo
A thin glass cable, approximately a little thicker than a human hair,
surrounded by a plastic coating. Fiber-optic cables transmit light pulses,
can transfer data at billions of bits per second, experience very low
noise, and are not sus
A special form of radio transmission that uses a focused ray of light in
the infrared frequency range, 1012-1014 Hz
A wireless transmission technology for the transfer of data between
smaller, often imbedded devices that requi
Universal Mobile Telecommunications Systems - U M T S
A third-generation cellular telephone technology that is capable of
supporting data transmission in 100's of kilobits per second.
1 x Enhanced Version - 1 x E V
A third generation cellular telephone te
The group of 100-Mbps Ethernet standards designated by the IEEE
100 Base TX
An 802.3 standard, created by IEEE for Ethernet, or CSMA/CD local
area networks, that incorporates 100-Mbps baseband, digital, signaling
Time Division Multiple Access - T D M A
A multiplexing technique used with PCS cell phones based upon time
division multiplexing that divides the available user channels by time,
giving each user a time to transmit.
Code Division Multiple Access - C D M A
Shared Segment Network
A local area network, or part of one, in which hubs interconnect multiple
workstations. When one workstation transmits, all workstations hear the
signal and thus all are sharing the bandwidth of the network segment.
Permission to install a medium across public or private property.
The first orbiting satellite in 1962.
Energy propagated through space and, indirectly, through solid objects
in the form of an advancing disturban
Spanning Tree Protocol, STP
An algorithm used by local area network switches that looks at all
possible paths within a network and creates a tree structure that includes
only unique paths between and two points. Switches use this algorithm
to avoid sendin
When a light wave bounces off a surface.
The change in direction experienced by a light wave as it passes from
one medium to another.
A fiber-optic transmission technique that sends a tightly focused stream
Logical Link Control, LLC, Sublayer
A sublayer of the data link layer of the OSI model that is primarily
responsible for logical addressing, and for providing error control and
flow control information.
Frames on a CSMA/CD local area network that ar
An alteration performed on a unit of information intended to increase it
density during storage of transmission.
A synonym for a multi-port repeater that may also perform bridging and
An electrical cable in which the conductors share a common axis.
Coder-decoder. Device that typically uses PCM to transform analog
signals into a digital bit stream and digital signals back into analog.
Electrical techniques use
A MAC method in which any node may take control of the networkwhen
it is not in use by another node. While transmitting, stationscontinue to
listen for incoming signals (collisions) and emit a jamming signal to notify
all other station
The transmission media of a network.
Range of network numbers that is valid for use by nodes on an extended
AppleTalk network. The cable range value can be a single network
number or a contiguous sequence of several network numbers. Node
A wireless technology that transfers signals over short distances of 10
meters or less, through non metallic objects.
Another term for a personal area network. A collection of one or more
devices interconnected in a small area via wirel
A type of coaxial cable system that uses a digital signaling/transmission
technique in which the cable carries only channel of digital data.
A coaxial cable technology that transmits analog signals and is capable
A designation for twisted pair wiring that can support analog telephone
systems, rarely used today.
A designation for twisted pair wiring that can support digital telephone
systems such as T-1 and I S D N; rarely used today.
Category 2 Cabling
One of five grades of UTP cabling described in the EIA/TIA-586
standard. Category 2 cabling is capable of transmitting data at speeds
up to 4 Mbps. Compare with Category 1 cabling, Category 3 cabling,
Category 4 cabling, and Category 5
Content-addressable memory. See associative memory.
A circuit board that plugs into a computer's bus to extend the computer's
Electromagnetic wave or alternating current of a single frequency,
suitable for modulation by anothe
10 Base 2
An 802.3 standard, created by IEEE for Ethernet, or CSMA/CD local
area networks, that incorporates 10-Mbps baseband, digital, signaling
for transmitting data over coaxial cable for a maximum segment length of
185 or 200 meters.
1 Base 5