This document discusses computer communication and networks. It defines computer communication as the process of exchanging data, instructions, and information between two or more computers or devices. It also lists the key components required for successful communication, including a sending device, communication devices, a communication channel, and a receiving device. The document then discusses various uses of communication technologies like email, instant messaging, wireless messaging services, collaboration tools, and voice mail. It defines a network as a collection of connected computers and devices that allows for sharing of hardware, data, information, software, and funds. Finally, it outlines different network types, communication software, and transmission media used for computer networks.

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