MOBILE AND ADHOC NETWORK(CSE901)

BY NEHA

CHOUDHARY ASST. PROFFESSOR

DEPT. OF CSE/IT LHST-A

INTRODUCTION TO WIRELESS

NETWORK

•A wireless network allows you to connect your computer to a network using radio waves instead of wires.•Mobility is possible within range.•Medium is wireless

TYPES OF WIRELESS NETWORKS

WLANS: Wireless Local Area Networks

WLANS allow users in a local area, such as a university campus or library, to form a network or gain access to the internet.

A temporary network can be formed by a small number of users without the need of an access point; given that they do not need access to network resources.

WPANS: Wireless Personal Area Networks

The two current technologies for wireless personal area networks are Infra Red (IR) and Bluetooth (IEEE 802.15).

These will allow the connectivity of personal devices within an area of about 30 feet.

However, IR requires a direct line of site and the range is less.

WMANS: Wireless Metropolitan Area Networks

This technology allows the connection of multiple networks in a metropolitan area such as different buildings in a city, which can be an alternative or backup to laying copper or fibre cabling.

WWANS: Wireless Wide Area Networks

These types of networks can be maintained over large areas, such as cities or countries, via multiple satellite systems or antenna sites looked after by an ISP. These types of systems are referred to as 2G (2nd Generation) systems.

UNDERSTANDING THE 802.11 FAMILY

The 802.11 standard first appeared in the 1990’s and was developed by the Institute of Electrical and Electronics Engineers.

802.11Using either FHSS or DSSS this provides a 1 to 2 Mbps transmission rate on the 2.4GHz band.

802.11aUsing the OFDM this provides up to 54Mbps and runs on the 5GHz band.

802.11bThis is also known as Wi-Fi or High Rate 802.11, uses DSSS and applies to wireless LANs.

It provides an 11 Mbps transmission802.11g

This provides a 20+ Mbps transmission rate, applies to LANs and runs on the 2.4GHz band.

EVOLUTION OF MOBILEThe first radiotelephone service was introduced in the US at the end of

the 1940s.In the 1960s, a new system launched by Bell Systems, called Improved

Mobile Telephone Service" (IMTS).The first analog cellular systems were based on IMTS and developed

in the late 1960s and early 1970s.(why cellular?)The evolution of mobile phones can be divided into four

stages:First Generation Second Generation2.5 GenerationThird Generation

First generation:- 1G analog system for mobile communications saw two key improvements during the 1970s:

invention of the microprocessor (why?)digitization of the control link between the mobile phone and

the cell site AMPS ( Advance mobile phone system ) was first launched by

US which is 1G mobile system.(It is based on FDMA technology which allows users to make voice calls within one country)

1G Phone

Second generation:- 2G digital cellular systems were first developed at the end of the 1980s( These systems digitized not only the control link but also the voice signal).

The first digital cellular phone call was made in the United States in 1990, and the first GSM network opened in Europe in 1991.

The new system provided better quality and higher capacity at lower cost to consumers.

GSM (Global system for mobile communication) was the first commercially operated digital cellular system which is based on TDMA.

2G Phone

2.5 Generation Mobile Systems (2.5G)These systems provide some of the features of 3G

without fulfilling the promised high data rates or full range of multimedia services.

These systems provide some of the features of 3G without fulfilling the promised high data rates or full range of multimedia services.

The move into the 2.5G world began with the General Packet Radio Service (GPRS)

GPRS is the most significant step towards the third generation of mobile systems because it supports flexible data transmission and it allows continuous connection to the network.

Third generation:- 3G systems promise faster communications services, including voice, fax and Internet, anytime and anywhere with seamless global roaming.

ITU’s IMT-2000 global standard for 3G has opened the way to enabling innovative applications and services (e.g. multimedia entertainment, infotainment and location-based services, among others).

The first 3G network was deployed in Japan in 2001. 2.5G networks, such as GPRS (Global Packet Radio Service) are already available in some parts of Europe.

3G technology supports 144 Kbps bandwidth, with high speed movement (e.g. vehicles), 384 Kbps (e.g. on campus) & 2 Mbps for stationary (e.g.in building )

http://www.5min.com/Video/The-Evolution-of-Mobile-Phones-19733841

3G Phone

THANKS!