Partner Link

Cheap Mobile Phones
- Cheap Mobile Phones - Best Mobile Phone Deals, Laptops, Sat Nav Devices, Cordless Phones, Internet Phones, Broadband Internet Deals from leading retailers of UK. Choose Products and Compare Prices for best deals.

||

Mobile Phones
- Offers mobile phones on contract, pay as you go, sim free deals with free gifts. We compare latest phone deals from leading retailers of UK.

. ||

Custom logo design
Get your company a logo design. Professional logo designs by expert logo designers. Call 0208 133 2514 for custom logo design packages.

||

Top Site

Flyer Printing Flyer Printing – Print your flyers on latest design. We offer cheap flyer printing services in all over UK. Full color flyer printing & art work in your own budget. Order for online flyer printing from your home.
Mobile Broadband Deals  Mobile Broadband - Buy Mobile Broadband Deals, Best Mobile Internet Offers With Free Line Rental, USB Modem and Cheapest Network Connection Offers from 3 Mobile in UK
Mobile Upgrades Upgrade Mobile Phone Deals – upgrade your mobile phones from o2, orange, virgin, vodafone, t-mobile and all Manufacturers Nokia, Samsung, Sony Ericsson, LG ,Blackberry and Motorola. Mobile Broadband Deals Mobile Broadband - Buy Mobile Broadband Deals, Best Mobile Internet Offers With Free Line Rental, USB Modem and Cheapest Network Connection Offers from 3 Mobile in UK.

Components of a Data Comm. Systems


Components of a Data Com Systems
Components of a Data Com Systems
Any system is made up of more than one component. Similarly, a data communication
system is made up of 5 components as shown in the fig:

  • Message
  • Sender
  • Receiver
  • Medium
  • Protocol
MESSAGE
  • Information or Data to be communicated
  • Can be text, numbers, video or any combination of these
  • In short anything that can be represented using binary bits
Data Communication Messages
Files (meaningful collections of records)
Data/information requests (database queries, Web page requests,
etc.)
Responses to requests and commands or error messages
Status messages (about the network’s functional status)
Control messages transmitted between network devices to control
network traffic
Correspondence among network users

MESSAGE TYPES
SENDER
  • Device that sends the data message
  • Can be a Computer , Workstation, Video camera etc
  • As already discussed, the data from the sender might not be in the appropriate format for the transmission medium and will need to be processed
RECEIVER
  • Device that receives the message
  • Can be a computer, workstation, Television etc
  • At times, the data received from the transmission medium may not be in a proper form to be supplied to the receiver and it must be processed
MEDIUM
  • Physical path that a message uses to travel from the Sender to the Receiver
  • Can be a Copper Cable (Telephone), Coaxial Cable (Cable TV), Fiber Optic Cable, LASERS or Radio Waves (Wireless Medium)
  • We will see that Data needs to be transferred in the form of ELECTROMAGNETIC signals and The Transmission Medium should be capable of carrying these EM Signals
Transmission Media

PROTOCOL
  • Set of Rules Governing Communication
  • Represents an Agreement between communication devices
  • Without Protocol, two devices may be connected but they will not be able to communicate
EXAMPLE: Consider the communication between two
individuals. They can only communicate provided they
both speak the same language.