Chapter 3: Introduction to Data Communications and Networking

clashjudiciousElectronics - Devices

Nov 8, 2013 (4 years and 4 days ago)

68 views

Chapter 3: Introduction to Data
Communications and
Networking



Data



information (knowledge or intelligence) that is stored in digital
form



Data Communication Circuit




equipment to transfer digital information from one place to
another


Data Communication Network



set of devices interconnected by media link



Data Communication Network Architecture



current



legacy



legendary


Data



frames, blocks or packets


Data Communication Network



broadcast ( messages for all subscribers on the network )



point
-
to
-
point



multicast ( messages for a specific group of subscribers )


Protocol



procedures
that the systems involved in the communications
process will use





Data Communications Circuits

Utilize electronic communications equipment and facilities to
interconnect digital computer equipment. There are




Source



Transmitter ( convert data to different and appropriate form )



Transmission medium



Receiver (convert the encoded signals to the original form )



Destination



Serial and Parallel Data Transmission





parallel by bit ( for
short

distance data line )



serial by bit (for
long
distance)



Data Communication Circuit Arrangements



Two
-
point



involve only two locations or stations



Multi
-
point



involve a host (such as mainframe computer) to many PCs




Transmission Modes




Simplex



data can be sent only one direction



Half duplex



data can be sent in both direction but not the same time



Full duplex



Full/full duplex



data transmission can be sent in both direction at the same
time but not between the same stations









Networking Applications



Standard office applications



E
-
mail, file transfers and printing



High
-
end office applications



Video imaging, CAD, software development



Manufacturing automation



Process and numerical control



Mainframe connectivity



PC, workstations, terminal support



Multimedia application



Live interactive video













Network Components, Functions, and Features


-
Servers (computers that hold shared files, programs and the
network operating systems)


-
Clients


-
Transmission media


-
Shared data


-
Shared printers and other peripherals


-
Network interface card


-
Local operating system


-
Network operating system








Network Classifications








LAN


10 to 40 computers


bit rates in the range of 10Mbps to 100Mbps


MAN


Similar to LAN but include larger area


Operate at speeds of 1.5 Mbps to 10 Mbps


Generally use one or two cables


Could be a single network such as a cable television network


Large companies often use their MAN to connect their LAN


WAN


GAN


the internet is a good example of GAN