Mobile Networks Asst. Prof. Dr. Mohammad kaleem Computer Engineering Department, National University of Sciences and Technology, Islamabad.

Mobile Networks

Asst. Prof. Dr. Mohammad kaleemComputer Engineering Department,

National University of Sciences and Technology, Islamabad

Text Book

•Wireless Communications and Networks, by William Stallings, Prentice Hall, 2nd Edition, 2005 •This textbook will be followed for most of the course.  •The material on multihop and sensor networks will be taken from research papers, and other collections.

Prerequisites Computer Communications And Networks Digital Communications

Introduction

Chapter 1

Wireless Comes of Age Guglielmo Marconi invented the wireless telegraph in

1896 Communication by encoding alphanumeric characters in

analog signal Sent telegraphic signals across the Atlantic Ocean

Communications satellites launched in 1960s Advances in wireless technology

Radio, television, mobile telephone, communication satellites More recently

Satellite communications, wireless networking, cellular technology, ad hoc networks, Sensor networks

Broadband Wireless Technology Higher data rates obtainable with broadband

wireless technology Graphics, video, audio

Shares same advantages of all wireless services: convenience and reduced cost Service can be deployed faster than fixed service No cost of cable plant Service is mobile, deployed almost anywhere

Future Generations

Rate

Mobility

2G

3G

4G

802.11b WLAN

2G Cellular

Other Tradeoffs: Rate vs. Coverage Rate vs. Delay Rate vs. Cost Rate vs. Energy

Fundamental Design Breakthroughs Needed

802.11n

Wimax/3G

Evolution of Current Systems Wireless systems today

3G Cellular: ~200-300 Kbps. WLANs: ~450 Mbps (and growing).

Next Generation is in the works 4G Cellular: Likely OFDM/MIMO 4G WLANs: Wide open, 3G just being finalized

Technology Enhancements Hardware: Better batteries. Better circuits/processors. Link: Antennas, modulation, coding, adaptivity, DSP,

BW. Network: more efficient resource allocation

Application

Transport

Network

Data Link

Physical

Medium

Data Link

Physical

Application

Transport

Network

Data Link

Physical

Data Link

Physical

Network Network

Radio

Scope of this course:

Anything above and related protocols

Wireless communication systems Target information systems: “Anytime,

Anywhere, Anyform” Applications: Ubiquitous computing and

information access Market in continuous growth:

35-60% annual growth of PCS (Personal Communications Services) Number of subscribers:

by 2001: over 700M mobile phones by 2003: 1 billion wireless subscribers (source Ericsson)

300% growth in wireless data from 1995-1997 Large diversity of standards and products Confusing terminology

Mobile Subscribers in Pakistan       Customers of Mobile Service Providers in Pakistan*

 YearMobilin

kUfone Paktel

Instaphone

Telenor

Warid Total Growth Rate

2000 114,272   80,221 112,000     306,493 15.39

2001 309,272116,71

196,623 220,000     742,606 142.29

2002 800,000 350,00

0218,53

6330,000     1,698,53

6128.73

20031,115,00

0 550,00

0319,40

0 420,000     2,404,40

041.56

20043,215,98

9801,16

0470,02

1535,738     5,022,90

8108.90

20057,469,08

5 2,579,1

03924,48

6454,147

835,727

508,655

12,771,203

154.26

Jul-05

Company wise Data is updated on Quarterly Basis

14,119,257

10.56

Aug -0515,511,0

459.7

More than 15,511,045 subscribers of Cellular Networks

*From Telecom Indicators section of PTA Website

Mobile Subscribers in Pakistan

0 2,000,000 4,000,000 6,000,000 8,000,000

Mobilink

Ufone

Paktel

Instaphone

Telenor

Warid2005

2004

2003

2002

2001

2000

Limitations and Difficulties of Wireless Technologies Wireless is convenient and less expensive Limitations and political and technical difficulties

inhibit wireless technologies Lack of an industry-wide standard Device limitations

E.g., small LCD on a mobile telephone can only displaying a few lines of text

E.g., browsers of most mobile wireless devices use wireless markup language (WML) instead of HTML

Wireless around us…

WLAN, DAB, GSM, etc…

Personal Travel Assistant,PDA, Laptop, GSM, cdmaOne,WLAN, Bluetooth, ...

Radio frequency spectrum

Wireless technologies have gradually migrated to higher frequencies

Wireless & Mobility Wireless:

Limited bandwidth Broadcast medium: requires multiple access schemes Variable link quality (noise, interference) High latency, higher jitter Heterogeneous air interfaces Security: easier snooping

Mobility: User location may change with time Speed of mobile impacts wireless bandwidth Need mechanism for handoff Security: easier spoofing

Portability Limited battery, storage, computing, and GUI

Challenges in Mobile Networking

Three major challenges: Wireless Channel Mobility Device Limitation

Part One: Background Provides preview and context for rest of

book Covers basic topics

Data Communications TCP/IP

Chapter 2: Transmission Fundamentals Basic overview of transmission topics Data communications concepts

Includes techniques of analog and digital data transmission

Channel capacity Transmission media Multiplexing

Chapter 3: Communication Networks Comparison of basic communication

network technologies Circuit switching Packet switching Frame relay ATM

Chapter 4: Protocols and the TCP/IP Protocol Suite Protocol architecture Overview of TCP/IP Open systems interconnection (OSI)

reference model Internetworking

Part Two: Wireless Communication Technology Underlying technology of wireless

transmission Encoding of analog and digital data for

wireless transmission

Chapter 5: Antennas and Propagation Principles of radio and microwave

Antenna performance Wireless transmission modes Fading

Chapter 6: Signal Encoding Techniques Wireless transmission

Analog and digital data Analog and digital signals

Chapter 7: Spread Spectrum Frequency hopping Direct sequence spread spectrum Code division multiple access (CDMA)

Chapter 8: Coding and Error Control Forward error correction (FEC) Using redundancy for error detection Automatic repeat request (ARQ) techniques

Part Three: Wireless Networking Examines major types of networks

Satellite-based networks Cellular networks Cordless systems Fixed wireless access schemes

Use of mobile IP and Wireless Access Protocol (WAP) to provide Internet and Web access

Chapter 9: Satellite Communications Geostationary satellites (GEOS) Low-earth orbiting satellites (LEOS) Medium-earth orbiting satellites (MEOS) Capacity allocation

Chapter 10: Cellular Wireless Networks Cellular wireless network design issues First generation analog (traditional

mobile telephony service) Second generation digital cellular networks

Time-division multiple access (TDMA) Code-division multiple access (CDMA)

Third generation networks

Chapter 11: Cordless Systems and Wireless Local Loop Cordless systems Wireless local loop (WLL)

Sometimes called radio in the loop (RITL) or fixed wireless access (FWA)

Chapter 12: Mobile IP and Wireless Access Protocol Modifications to IP protocol to

accommodate wireless access to Internet Wireless Application Protocol (WAP)

Provides mobile users access to telephony and information services including Internet and Web

Includes wireless phones, pagers and personal digital assistants (PDAs)

Part Four: Wireless Local Area Networks Examines underlying wireless LAN

technology Examines standardized approaches to local

wireless networking

Chapter 13: Wireless LAN Technology Overview of LANs and wireless LAN

technology and applications Transmission techniques of wireless LANs

Spread spectrum Narrowband microwave Infrared

Chapter 14: IEEE 802.11 Wireless LAN Standard Wireless LAN standards defined by IEEE

802.11 committee

Chapter 15: Bluetooth Bluetooth is an open specification for

wireless communication and networking Personal computers Mobile phones Other wireless devices

Internet and Web Resources Web page for this book

WilliamStallings.com/Wireless1e.html Useful web sites, errata sheet, figures, tables, slides,

internet mailing list, wireless courses Computer Science Student Support Site

WilliamStallings.com/StudentSupport.html Newsgroups

comp.std.wireless comp.dcom.*