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

is the largest computer network in the world. Its predecessor, Advanced Research Projects Agency Network (ARPAnet), was born in 1969.

refers to communication between terminal devices through a computer network.

This refers to a sign or indication that conveys information about something or that tells someone to do something.

This refers to an event or act, which shows that something exists or that gives information about something.

This refers to a detectable physical quantity or impulse (as a voltage, current, or magnetic field strength) by which messages or information can be transmitted via telegraphy, telephony, radio, radar, or television.

voltages and currents

audio or speech signals

intensity variations in an image)

sequence of bases in a gene)

interference – undesired form of signal)

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

refers to the horizontal distance of a wave from a point to the corresponding point on the next wave. This is measured in meters (m) in SI.

refers to a vertical distance from a given point on the wave from the horizontal axis.

describes the position of the waveform relative to time zero; it is a measurement of the delay of the wave relative to some fixed reference point or another sine wave.

refers to the number of waves made per second or as cycles per second. It is the reciprocal of the period to complete one (1) wave cycle. The unit for frequency is in Hertz (Hz); 1 Hz means 1 cycle per second (cps).

refers to the amount of time (expressed in seconds) required to complete one (1) full cycle.

is a wave in which both the amplitude and time continuously vary over their respective intervals that results in a wavy characteristic.

is a wave with several discrete (jumpy) states, such as high or low, and on or off.

Computers facilitate information exchange and resource sharing from one location to another through some sort of wiring/cabling or waves that act as a physical path, which carries electrical or electromagnetic signals between a transmitter and a receiver.

These networking media use cables and are limited by physical geography.

In contrast to wired or bounded media, these networking media do not use any cables in transmitting data and is not bounded by physical geography.

is a connection wherein data flows in one (1) direction only (unidirectional). This type is either transmit-only or receive-only.

is a connection wherein data can flow in both directions, but not simultaneously (both at the same time) over a shared physical medium.

is a connection wherein data simultaneously flows in both directions

is a transmission in which data with each bit lining up in a series as the bits are sent over a single wire at a time.

is a transmission wherein a group of bits is sent simultaneously, but each uses a different channel.

The most widely used standard for serial data communications is which is intended to operate over distances of up to 50 feet and has a communication speed that is equal to or less than 20Kbps.

refers to two (2) conductors enclosed by an insulating protective coating.

is a flexible coaxial cable about 0.25 inches thick. It uses British Naval Connector (BNC)-T cable connector attached to LAN Card (NIC).

is a relatively rigid coaxial cable about 0.5 inches in diameter. It uses vampire tap or piercing tap as connectors.

consists of two insulated strands of copper wire that are arranged in a regular spiral pattern.

As the name implies, a UTP cable refers to a twisted pair cable that contains no shielding

As the name implies, an STP cable refers to a twisted pair cable that combines the techniques of twisting wires, cancellation, and shielding.

refers to signal loss due to impedance.

refers to the twisted-wire pairs producing a magnetic field cancellation effect, which limits signal degradation caused by interference from nearby twisted pairs.

refers to a bundle of extremely thin and cylindrically shaped glass fibers surrounded by a concentric layer of glass coating that can conduct modulated light transmissions.

refers to the innermost section that consists of one (1) or more very thin strands or fibers made of glass or plastic.

refers to an outer optical glass or plastic coating that surrounds and traps the light in the core by the principle of total internal reflection.

is made from plastic that helps to shield the core and cladding from damage.

stand as protection for the core against compressive forces or crushing and tension or excessive pulling.

refers to an outermost layer that protects a buffer or a bundle of buffer-coated fibers against moisture, abrasion, crushing, and other environmental dangers.

This fiber optic cable type allows light waves to travel along a single path or in only one mode. It is used for high-speed transmission over long distances.

This fiber optic cable type allows light waves to travel into numerous paths through the core of the fiber at various angles. It is often applied to local area networks which encompass a much smaller transmission range.

Computers also facilitate information exchange and resource sharing from one location to another through waves which act as physical paths that carry current or series of electromagnetic energy pulses at various frequencies.

refers to a wireless medium that is used for multicast communications (e. g. radio and TV broadcasting, wireless local loop, mobile communications, and amateur radio) and paging systems over long distances.

which is also known as aerial, refers to a metallic structure that acts as a transducer that converts electrical energy to electromagnetic energy (upon transmission of signal) and vice-versa.

It is a method by which radio waves travel from the transmitting antenna to the receiving antenna.

It is a method by which radio waves are radiated directly towards the earth’s surface. It is used for:

It is a method by which radio waves radiate upwards from the transmitting antenna of the earth into a direction towards the ionosphere.

It is a method by which radio waves radiation exceeds 30 MHz up to 300 GHz.

refers to a wireless medium that is used for short-range communication in a closed area using LOS propagation.

refers to a wireless medium that is used for unicast communication such as wPAN, WiMAX, wireless WAN (2G/3G), satellite networks, and Wi-Fi.

allows devices to transmit data or voice wirelessly over a short distance. It uses the same 2.4GHz frequency.

It is a schematic description of a network arrangement, connecting various nodes (sender and receiver) through lines of connection.

in this type of topology, the computers are connected to a single hub through a cable.

a network type in which every computer and network device is connected to a single cable.

All nodes are connected through a bus (ex. coaxial cable).

forms a ring as each computer is connected to another computer, with the last one (1) connected to the first —exactly two (2) neighbors for each device.

has a root node and all other nodes are connected to it forming a hierarchy.

a point-to-point connection to other nodes or devices.

in this topology, some systems are connected in the same fashion as mesh topology, but some devices are only connected to two (2) or three (3) devices.

each node or device is connected.

it consists of a mix of two (2) different types of topologies merging as one network.

It is the end-device of the data communication system.

This includes___ Such as a pc, phone, handsets, printers, and servers

is a key component that connects directly to a device that allows access to a network such as an internet or a local network.

It is the device closest to end-users, used to access the network and switch data frames.

Switches belonging at the access layer are usually Layer 2 switches, also known as

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

It is a network-layer device that forwards data packets on the Internet.

is a device that connects a network to the Internet.

takes signals from your___ and translates them into signals connected to the local devices.

is a term for a router that provides functions such as protocol conversion, route selection, and data exchange when networks using different architectures or protocols communicate with each other.

It is a network security device used to ensure secure communication between two networks.

It is a network that uses radio waves, laser, and infrared signals to replace some or all transmission media in a wired LAN.

applies to homes. It works independently and needs to be configured separately. It has simple functions and low costs.

applies to medium- and large-sized enterprises. It needs to work with the AC and is managed and configured by the AC.

is generally deployed at the aggregation layer of the entire network.

* generally covers an area of a few square kilometers. * The main function is to connect several terminals that are close to each other (within a family, within one or more buildings, within a campus, for example).

is a large-sized LAN, requiring high costs but can provide a higher transmission rate.

generally covers an area of several kilometers or larger (thousands of kilometers for example).

is a descriptive network scheme. Describes how information or data makes its way from application programs through a network medium to another application program located on another network.

OSI layer that is closest to the user.

ensures that the information that the application layer of one (1) system sends out is readable by the application layer of another system.

defines how to start, control and end conversations (called sessions) between applications.

regulates information flow to ensure end-to-end connectivity between host applications reliably and accurately.

defines end-to-end delivery of packets. It defines how routing works (identifying endpoints) and how routes are learned so that the packets can be delivered.

provides access to the networking media and physical transmission across the media and this enables the data to locate its intended destination on a network.

The data link layer provides reliable transit of data across a physical link by using the

deals with the physical characteristics of the transmission medium.

It is a networking model with a set of communication protocols for the Internet and similar networks.

provides basic communication.

provides key functions that applications need.

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

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

is responsible for the delivery of service requests that respond from the transport layer and have them arrive at their destination through the "virtual network" image of the Internet.

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