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.
