mobile networks asst. prof. dr. mohammad kaleem computer engineering department, national university...
TRANSCRIPT
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.
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, ...
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
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.*