WMC630 Wireless and mobile computing: Introduction

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(WMC-630) Wireless and mobile computing
Introduction

• Summarized by
• Neetesh Purohit
• Lecturer, IIIT,
• Allahabad, UP, India
• http//profile.iiita.ac.in/np/

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Various streams in wireless/mobile domain

• Mobile Communication
• (Developing wireless n/w e.g. WLAN, WLL, GSM,
  bluetooth etc and related protocols for their
  proper working)
• Mobile Computing
• (Developing applications for wireless networks
  e.g. SMS, hello tunes etc)
• Pervasive Computing
• (Developing context aware applications for
  wireless networks)

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Requirements of the course

• Fundamentals of digital comm. theory
• Fundamentals of antenna theory
• Modes of propagation in space
• Fundamentals of Computer n/w
• (layered architecture, protocols, service
  primitives, service types, multiple access etc.)

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The syllabus

• Unit I
• Basic concepts of communication and antenna
  theory, Various modes of wireless transmission,
  Multiple access techniques, Spread spectrum
  techniques, Capacity allocation in satellite
  communication.
• Unit II
• Principles of cellular mobile systems -
  Architecture, Channel assignment, Interference
  and system capacity, Repeaters, Cell sectoring,
  Cell splitting, Microcell zone concept, Erlang
  B and Erlang C formula, handoff considerations,
  Prioritizing handoffs.
• Unit III
• Large scale path loss models, Small scale fading
  and multipath, Modulation techniques for mobile
  communication, Equalization, Diversity

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• Unit IV
• Speech coding techniques, Global System for
  mobile (GSM), GPRS, EDGE,
• Unit V
• Mobile IP, WAP, DECT Cordless systems, IS-95
  (CDMA Mobile)
• Unit VI
• Wireless LAN and IEEE 802.11, Fixed WLL and
  802.16 standard, UMTS, cdma2000, SS7, Bluetooth
  technology

• Text Book
• (i) Wireless Communication T S Rappaport PE
• (ii) Wireless Communication and networks W
  Stallings PE
• Reference books
• 1. Mobile cellular Telecomm W C Y Lee MH
• 2. Mobile Communications Schiller PE
• 3. Wireless and Mobile network Architecture Y B
  Lin JW
• 4. Fundamentals of mobile Pervasive computing
  F A delstein TMH
• 5. UMTS The fundamentals B Walke JW
• 6. GSM, GPRS and EDGE Performance T Halonen JW

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The Architecture of cellular network
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Figure 1.6 Timing diagram illustrating how a
call to a mobile user initiated by a landline
subscriber is established.
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Figure 1.7 Timing diagram illustrating how a
call initiated by a mobile is established.
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Evolution of cellular system

• In 1946, the first mobile telephone service was
  introduced in 25 American cities.
• Each system used a single, high powered
  transmitter and large tower to cover distances
  over 50 Km with 120Khz RF bandwidth half duplex
  channels.
• Problems
• Bulky mobile unit
• low battery life
• poor service performance (high blocking rate,
  inefficient spectrum utilization)

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The solutions

• Cellular architecture
• Hexagonal cells (min BS, easier HO)
• Very high blocking and dropping rate
• Frequency reuse concept (improved blocking,
  cochannel interference)
• Cluster size (N) i2j2ij
• Introduction of handoff (improved dropping)

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Analog cellular system

• In 1983, first analog cellular system was
  deployed in Chicago, USA with 30Khz RF bandwidth
  full duplex channels (first generation system).

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Second generation systems

• In 1990, GSM was introduced by European countries
  which supports 8 users in 200Khz RF bandwidth (25
  khz per user)
• In 1991, the US Digital Cellular system (IS- 136)
  was installed which supports 3 users in 30 khz RF
  bandwidth ( 10Khz per user)
• In 1993, Qualcomm developed an CDMA mobile system
  (IS-95).

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Cellular service in India

• 31st July 1995, Indias first mobile service was
  launched in Calcutta.
• It was a GSM network (why India adopted GSM?)
• Reliance group had launched first CDMA service in
  India.