TAILIEUCHUNG - Lecture Wireless and mobile computing – Chapter 9: Communication networks

The following will be discussed in this chapter: Wireless communication? Why use wireless communication? Wireless is different than wired why? Modern cellular standards, underlying concepts, enabling technologies, overview of wireless LANs, single cell LAN extension, nomadic access,. | Communication Networks Lecture 9 1 Wireless Communication? Any form of communication that does not require the transmitter and receiver to be in physical contact through guided media Electromagnetic wave propagated through free-space Radar, RF, Microwave, IR, Optical Simplex: one-way communication (., radio, TV) Half-duplex: two-way communication but not simultaneous (., push-to-talk radios) Full-duplex: two-way communication (., cellular phones) Frequency-division duplex (FDD) Time-division duplex (TDD): simulated full-duplex 2 2 Why Use Wireless Communication? Provides mobility A user can send and receive messages no matter where he/she is located Added convenience / reduced cost Enables communications without adding expensive infrastructure Can easily setup temporary wireless LANs (disaster situations) Developing nations use cellular telephony rather than laying wires to each home Use resources only when sending or receiving signal 3 3 Wireless is Different Than Wired Why? Noisy, time-varying channel BER varies by orders of magnitude Enviromental conditions affect transmission Shared medium Other users create interference Must develop ways to share the channel Bandwidth is limited TÜK, FCC determines the frequency allocation ISM band for unlicensed spectrum (902-928 MHz, GHz, GHz) Requires intelligent signal processing and communications to make efficient use of limited bandwidth in error-prone environment 4 4 Modern Cellular Standards First generation (1G) systems (analog) 1979: NTT (Japan), FDMA, FM, 25 kHz channels, 870-940 MHz) 1981: NMT (Sweden and Norway), FDMA, FM, 25 kHz, 450-470 MHz 1983: AMPS (US), FDMA, FM, 30 kHz channels, 824-894 MHz 1985: TACS (Europe), FDMA, FM, 25 kHz channels, 900 MHz Second generation (2G) systems (digital) Supported voice and low-rate data (up to kbps) 1990: GSM (Europe), TDMA, GMSK, 200 kHz channels, 890-960 MHz 1991: USDC/IS-54 (US), TDMA, π/4 DQPSK, 30 kHz channels, 824-894 MHz 1993: IS-95 .

• Quản trị mạng
• Mobile computing
• Wireless and mobile computing
• Services data
• Wireless communication
• Communication networks
• Modern cellular standards
• Transmission fundamentals
• Mobile computing transmission fundamentals
• Mobile computing simulations
• Network simulation
• Addressing routing
• Visualization tool
• Signals for conveying information
• Digital data transmission
• Mobile systems
• Mobile services
• Lecture Electronic commerce
• Electronic commerce
• Define mobile commerce
• Personal digital assistant
• Wireless mobile computing
• Lecture Mobile applications overview
• Mobile applications overview
• Mobile computing devices
• Mobile applications becoming ubiquitous
• Mobile cloud computing
• Mobile web services
• Cloud computing
• Medical cloud multi agent system
• New mobile medical
• Introduction to Mobile Cloud Computing
• MCC Architecture
• Advantages of MCC
• MCC Applications
• MCC Issues
• Error control
• Digital communication system
• Error detection
• Cyclic Redundancy Check
• Software defined radio
• Satellite communications
• Satellite foot print
• Wireless LAN technology
• Electromagnetic radiation spectrum
• Wireless media standards
• Requirement of protocol
• OSI model
• Protocol suit
• Network access layer
• Transport layer