Mobile and wireless networking in mobile computing.pptx

Mobile and wireless networking in mobile computing

1. Mobile Computing Lecture #02 By Hannan Bin Liaqat Department of CS& IT University of Gujrat

2. Today’s Lecture Agenda What is Wireless Networks? Types of Wireless Networks History of Wireless Networks Advantages of Wireless Networks Disadvantages of Wireless Networks

3. What is Networks? Definition: Two or more computer or computing devices connected together through connecting devices Purpose of networking: 1- Communication 2- Sharing

4. Types of Networks There are mainly two types of networks 1- Wired networks 2- wireless networks Wired Networks: In which all computer or computing devices are connected through guided medium (cables)

5. Types of Networks Wireless Networks: in which all computers and computing devices are connected through unguided medium (radio waves)

6. Wireless Networks … Wireless Networks operate in almost the same way as wired Networks Using the same networking protocols Supporting almost the same applications

7. Types of Wireless Networks There are mainly two types of wireless networks 1- Infrastructural wireless networks 2- Infrastructure less wireless networks Infrastructural wireless networks: Definition: Infrastructure wireless networks are the wireless network that contains wireless router/access point and enables other computers connect to it wirelessly. This is the common deployment to build a home wireless network.

8. Infrastructural wireless networks: Diagram: Basics Elements 1- wireless router/Access point R esponsible for sending packets between wired network and wireless hosts in its “area” 2- computers (lap top)/other devices 3- applications running on the computers

9. Infrastructure less wireless networks Ah Hoc Networks Infrastructure less networks are also called Ah hoc networks In this type of communication devices or computers communicate directly with each other without the need for a wireless router or access point Basics Elements 1- computers (lap top)/other devices Each computer is responsible for sending/forwarding packets to other computers in its area (transmission range) 2- applications running on the computers

10. Infrastructure less wireless networks Ah Hoc Networks

11. Early history of wireless communication Many people in history used light for communication heliographs, flags 150 BC smoke signals are used for communication; (Polybius, Greece) 1794, optical telegraph Introduction of electromagnetic waves: 1831 Faraday demonstrates electromagnetic induction J. Maxwell (1831-79): theory of electromagnetic Fields, wave equations (1864 ) H. Hertz (1857-94): demonstrates with an experiment the wave character of electrical transmission through space

12. History of wireless communication I 1895 Marconi first demonstration of wireless telegraphy (digital!) long wave transmission 1907 Commercial transatlantic connections huge base stations 1915 Wireless voice transmission New York - San Francisco 1920 Discovery of short waves by Marconi reflection at the ionosphere smaller sender and receiver, possible due to the invention of the vacuum tube 1926 Train-phone on the line Hamburg - Berlin wires parallel to the railroad track

13. History of wireless communication 1928 many TV broadcast trials (across Atlantic, color TV, TV news) 1933 Frequency modulation 1958 A- Netz in Germany analog, 160MHz, connection setup only from the mobile station, no handover, 80% coverage, 1971 11000 customers 1972 B- Netz in Germany analog, 160MHz, connection setup from the fixed network too (but location of the mobile station has to be known) 1982 Start of GSM-specification 1983 Start of the American AMPS (Advanced Mobile Phone System, analog) 1984 CT-1 standard (Europe) for cordless telephones

14. History of wireless communication 1986 C- Netz in Germany analog voice transmission, 450MHz, hand-over possible, digital signaling, automatic location of mobile device 1991 Specification of DECT Digital European Cordless Telephone (today: Digital Enhanced Cordless Telecommunications) 1992 Start of GSM 1994 E- Netz in Germany GSM with 1800MHz, smaller cells, supported by 11 countries 1996 HiperLAN (High Performance Radio Local Area Network) 1997 Wireless LAN - IEEE802.11 1998 Specification of GSM successors for UMTS (Universal Mobile Telecommunication System 1.13.1

15. Advantages of Wireless Networks Minimum installation issues Freedom to roam Scalability No cables

16. Disadvantages of Wireless Networks Careful planning of network essential Environment generally unfriendly Security Safety S pectrum licenses P oor data rates