NT1 PRELIM

Communication

The act of transmitting and exchanging information between people, people and objects, and objects and objects through various media and actions.

Internet

The largest computer network in the world, originating from ARPAnet in 1969.

Network Communication

Communication between terminal devices through a computer network.

Signal

A means of communication that conveys information about something or tells someone to do something.

Communicated Information

An event or act that shows existence or gives information about something.

Electronics Transmitted Information

A detectable physical quantity or impulse for transmitting messages or information via various communication technologies.

Electrical Signals

Voltages and currents in a circuit that convey information.

Acoustic Signals

Audio or speech signals used in communication.

Video Signals

Intensity variations in an image used for conveying visual information.

Biological Signals

Sequences of bases in a gene that convey biological information.

Noise

Unwanted and undesired forms of signal interference.

Waves

Disturbances in energy that travel through a medium from one location to another.

Wavelength

The horizontal distance of a wave from a point to the corresponding point on the next wave.

Amplitude

Vertical distance from a given point on the wave from the horizontal axis.

Phase

Describes the position of the waveform relative to time zero.

Frequency

The number of waves made per second; measured in Hertz (Hz).

Period

The amount of time required to complete one full cycle of a wave.

Analog Wave

A wave where both amplitude and time continuously vary over intervals.

Digital Wave

A wave with discrete states such as high or low, on or off.

Network Media

Physical paths for transmitting electrical or electromagnetic signals between a transmitter and a receiver.

Wired Media

Networking media using cables, limited by physical geography.

Wireless Media

Networking media that do not use cables and are not bound by physical geography.

Simplex Mode

A connection where data flows in one direction only.

Half-Duplex Mode

A connection where data can flow in both directions, but not simultaneously.

Full-Duplex Mode

A connection where data simultaneously flows in both directions.

Serial Transmission

Data transmission where each bit is sent over a single wire, one at a time.

Parallel Transmission

Data transmission where a group of bits is sent simultaneously over different channels.

Serial Cable

A standard for serial data communications operating over distances up to 50 feet.

Coaxial Cable

A cable consisting of two conductors enclosed by a protective coating.

Thin (Thinnet) Cable

Flexible coaxial cable about 0.25 inches thick.

Thick (Thicknet) Cable

Rigid coaxial cable about 0.5 inches in diameter.

Twisted Pair Cable

Consists of two insulated strands of copper wire arranged in a spiral pattern.

Unshielded Twisted-Pair (UTP) Cable

Twisted pair cable that contains no shielding.

Attenuation

Signal loss due to impedance.

Crosstalk

Magnetic field cancellation effect produced by twisted-wire pairs.

Shielded Twisted-Pair (STP) Cable

Twisted pair cable that combines twisting, cancellation, and shielding.

Fiber Optic Cable

A bundle of thin glass fibers that conduct modulated light transmissions.

Core

The innermost section of fiber optic cable made of glass or plastic.

Cladding

An outer coating that traps light in the core through total internal reflection.

Coating

Plastic material that protects the core and cladding from damage.

Strengthening Fibers

Protective fibers against compressive forces and tension.

Cable Jacket (Sheath)

Outermost layer protecting optical fibers from environmental dangers.

Single-Mode Fiber Optic Cable

Allows light to travel along a single path for high-speed, long-distance transmission.

Multimode Fiber Optic Cable

Allows light to travel in multiple paths through the fiber's core.

Radio Wave

A wireless medium for multicast communications and paging systems.

Antenna

A structure that converts electrical energy to electromagnetic energy.

Line of Sight

Method by which radio waves travel directly from one antenna to another.

Ground Wave

Radio waves radiated directly towards the earth’s surface.

Sky Wave

Radio waves that radiate upwards toward the ionosphere.

Space Wave

Radio waves exceeding 30 MHz up to 300 GHz.

Infrared

A wireless medium for short-range communication using line-of-sight propagation.

Microwave

A wireless medium used for unicast communication.

Bluetooth

Short-range wireless technology for data or voice transmission.

Network Topology

A schematic description of a network connecting various nodes.

Star Topology

Computers connected to a single hub, which acts as the central node.

Bus Topology

All computers connected to a single cable.

Ring Topology

Each computer connected to two others, forming a ring.

Tree Topology

A hierarchical structure with a root node and connected nodes.

Mesh Topology

A point-to-point connection among all network nodes.

Partial Mesh Topology

Some nodes connected in a mesh fashion while others connect to fewer devices.

Full Mesh Topology

Each node connected to every other node.

Hybrid Topology

A mix of two different types of topologies in one network.

Terminal Device

The end-device in a data communication system.

Network Interface Card (NIC)

A component that connects a device to a network.

Switch

A device used to access the network and switch data frames.

Broadcast Domain

A set of nodes that can receive broadcast packets from a node.

Router

A device that forwards data packets on the Internet.

Modem

A device that connects a network to the Internet.

Gateway

A router providing functions like protocol conversion and data exchange.

Firewall

A network security device ensuring secure communication between networks.

Wireless Devices

Devices using radio waves, laser, and infrared signals for data transmission.

Fat Access Point (Fat AP)

A standalone access point for homes that operates independently.

Fit Access Point (Fit AP)

An access point for enterprises managed by a central controller.

Access Controller (AC)

A device that provides wireless data control services.

Local Area Network (LAN)

A network covering a small geographical area, connecting terminals closely.

Metropolitan Area Network (MAN)

A large-sized LAN that covers a city or university campus.

Wide Area Network (WAN)

A network covering larger areas connecting multiple LANs or MANs.

Open Systems Interconnection (OSI) Model

A descriptive network scheme for how data travels through a network.

Application Layer

Layer closest to the user providing network services to applications.

Presentation Layer

Ensures information is readable between different systems.

Session Layer

Controls and manages sessions between applications.

Transport Layer

Regulates end-to-end connectivity and data flow between applications.

Network Layer

Defines delivery of packets and routing functions.

Data Link Layer

Provides access to networking media and transmission across it.

Physical Layer

Deals with the physical characteristics of the transmission medium.

TCP/IP Model

A networking model with communication protocols for the Internet.

Transmission Control Protocol (TCP)

Provides key functions required for data delivery.

Application Layer( TCIP MODEL)

Represents an interface through a variety of protocols that enable services to be applied to end-user application processes.

Transport Layer (TCIP MODEL)

Responsible for reliable end-to-end data delivery from the source host to the destination host.

Internet Layer (Network) (TCIP MODEL)

Responsible for delivery of service requests from the transport layer and having them arrive at their destination through the 'virtual network' image of the Internet.

Network Access Layer (TCIP MODEL)

Also called the host-to-network layer, concerned with all the issues that an IP packet requires to make a physical link to the network media.