Chapter 6 : Data communication Flashcards
What is the goal of data communication
To process information so that it is useful to specific users.
What is data communication
Using Computers to transfer data from one place to another.
Bandwidth
The amount of data that can be transferred from one point to another in a certain time period.
Example of and E- Collaboration tool
GoToMeeting
Components of a data communication system
- Sender and receiver devices
2.Modems or routers) - Communication medium (channel)
Attenuation
Signal decreases as distance increases
The two types of data transmission channels
- Broadband
- Narrowband
Broadbrand
Multiple pieces of data are sent simultaneously to increase transmission rate
Narrowband
Voice generated transmission medium channel capable of transmitting a maximum of 56 000bps, Therefore only a limited amount of information can be transferred in a specific period of time.
Sender and Receiver devices
- Input/output devices = thin clients
- Smart terminal
- Intelligent terminal
- Netbook computer
- Minicomputers, mainframes, and supercomputers
Smart terminal
An input / output device that can preform certain processing tasks but not a full featured computer.
Intelligent terminal, workstation, or personal computer
Input/output devices or stand alone systems. ( a step up a smart terminal.
Netbook computer
A low cost, diskless computer used to connect to the internet or a LAN.
What is DSL (Digital subscriber line)
- Makes use of normal telephone lines
- provides high speed transmission
-Modems need DSL to access the internet
Router
Connect network systems and control traffic flow between them.
Medium or data channel can either be:
- Wired = cabled
- Wireless = no cables
Purpose of the OSI Model
to standardize the transmission of data so that computers may communicate regardless of hardware and software.
How many layers in the OSI Model
7 layers
Going down the OSI Model means
Transmitting data
Going up the OSI Model means
Receiving data
Types of network divided by geographical area
- LAN
- MAN
- WAN
WAN
Spread over different countries
MAN
Same country different cities e.g Wllington, Paarl, Stellenbosch
Topology
refers to how the devices in the network are set up.
Protocol
A standard for processing and formatting data
Routing
route by which packets of data are delivered
Horizontal scalability
More clients
Vertical scalability
more servers
What is the role of the client in a client server model?
local computer that communicates with and requests information from server
What is the role of the server in a client server model
remote computer on network
Mobile networks
Operate on radio frequencies, consist of 3 parts:
1. Base stations
2. Mobile telephone switching offices
3. Subscribers
