1. Communications and
Networks
Lecture 23
Zikria Mian

2. • Computer communication
– A process in which two or more computers or
devices exchange data, instructions and
information.
– For successful communications, following are
required
• Sending device
• 2 Communication devices
• Communication channel
• A receiving device

3. • Most computer users require a
subscription to an internet service provider
• An organisation may provide
communication services to employees,
students, customers etc

4. Previously discussed uses of
communication
• E-mail
• Instant messaging
• Chat rooms
• Newsgroups
• Blogs
• Wikis
• RSS
• VoIP
• FTP
• Video conferencing etc

5. Other uses of communication
• Wireless messaging service
– Text messaging
– Instant messaging
– Multimedia messaging
• Wireless internet access points
– A ‘Hot spot’
– Mobile wireless network

6. • Global positioning system (GPS)
– A navigation system that consists of one or
more receivers that accept and analyse
signals sent by satellites, mainly for
determining geographical location
• Collaboration
– Collaborative software e.g. Acrobat connect,
Microsoft Office Live Meeting etc
– Via e-mail
– Document management system e.g. google
docs

7. • Voice Mail
• Web Services
– Software to communicate with other remote
computers
– Business usage
– Personal usage

8. Networks
• A network is a collection of computers and
devices connected together via
communication devices and transmission
media
– Network can be internal to an organisation or
worldwide through internet

9. Advantages
• Facilitating communications
• Sharing hardware
• Sharing data and information
• Sharing software
• Transferring funds

10. Types of Networks
• Local Area Network (LAN)
• Metropolitan Area Network (MAN)
• Wide Area Network (WAN)
• 802.11 (Wi-Fi)
– Wireless ethernet standard
– Wi-Fi mesh network
• Bluetooth
• UWB

11. • IrDA (line of sight transmission)
• Radio Frequency Identification (RFID)
• Worldwide Interoperability for Microwave
Access (WiMax)
• Wireless Access Protocol (WAP) and
General Packet Radio Service (GPRS)

12. Communications Software
• Help users to establish connection with
another computer or network
• Manage the transmission of data,
instructions and information
• Provide an interface for users to
communicate with one another

13. Transmission Media
• Physical Media
– Twisted-pair cable
– Coaxial cable
– Fiber-optic cable
• Wireless Media
– Infrared
– Broadcast Radio
– Cellular radio
– Microware radio
– Communication satellite