Ch 9 Communications and Networks

Router

A communications device that connects multiple computers together and transmits data to its correct destinations on a network

Adapter card

A dial-up modem usually is in this form, which is inserted in an expansion slot on a computer's motherboard.

Cellular radio

A form of broadcast radio that is used widely for mobile communications.

802.11

A series of network standards that specifies how two wireless devices communicate over the air with each other

3G

Examples of standards in this category include GSM and UMTS and can transfer data at speeds from 144Kbps to 2.4 Mbps.

Communications satellite

Space station that receives microwave signals from an earth-based station, amplifies the signals, and broadcasts the signals back over a wide area

Infrared

Wireless data transmission standard that transfers data at rates from 115 Kbps to 4 Mbps between their IrDA ports and requires a line-of-sight transmission

Hot spots

A wireless network that provides Internet connections to mobile computers and devices. Three common technologies used are Wi-Fi, WiMAX, and Bluetooth.

Broadcast radio

A wireless transmission medium that distributes radio signals through the air over long distances.

Global Positioning System (GPS)

A navigation system that consists of one or more earth-based receivers that accept and analyze signals sent by satellites in order to determine the receiver's geographic location.

Server

The host computer that controls access to the hardware, software, and other resources on the network and provides a centralized storage area for programs, data, and information.

Ultra-wideband (UWB)

A network standard that specifies how two devices use short-range radio waves to communicate at high speeds with each other such as wirelessly transferring video from a digital video camera

Transmission Control Protocol/Internet Protocol (TCP/IP)

A networks standard that defines how messages (data) are routed from one end of a network to the other, ensuring the data arrives correctly.

Online meeting

Allows participants to have the ability to open a separate window and type messages to one another.

2G

Category of cellular transmission that transmits digital data at speeds from 9.6 Kbps to 19.2 Kbps.

4G

Category of cellular transmission that transmits digital data at speeds up to 15 Mbps.

Wireless Access Point

Central communications device that allows computers and devices to transfer data wirelessly

Coaxial

Consists of a single copper wire surrounded by at least three layers: 1)an insulating material, 2) a woven or braided metal, and 3) a plastic outer coating

Dedicated server

Performs a specific task and can be placed with other servers to perform multiple tasks.

Latency

The time it takes a signal to travel from one location to another on a network. Can be negatively affected by the distance between two points, the type of transmission media, and the number of nodes through which data must travel.

Twisted-pair

Kind of cable designed to reduce noise and consists of one or more pairs of insulated copper wire bundled together

Clients

Other computers and mobile devices on the network that rely on the server for its resources.

bandwidth

The amount of data, instructions, and information that can travel over a communications channel

Fiber-optic

The core of this kind of cable consists of dozens or hundreds of thin strands of glass or plastic that use light to transmit signals.

Bluetooth

This kind of device uses short-range radio waves to transmit data and contains a small chip that allows it to communicate with other similar devices.

Wireless

Transmission media that sends communications signals through the air or space using radio, microwave, and infrared signals.

Physical

Transmission media that uses wire, cable, and other tangible materials to send communications signals.

Dedicated line

Type of always-on connection established between two communications devices that can be either analog or digital.

P2P

Type of peer-to-peer internet network that is sometimes called a file sharing network.

Transmission media

When you send data from a computer, the signal that carries the data may travel over this type of Materials or substances capable of carrying one or more signals.