Introduction
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Introduction NES440 Wireless Networks NES440 Wireless Networks 1 NES440 Wireless Networks 3 Outline What is “Wireless and Mobile Networking”? What is wireless networking? What is Mobility? Degrees of Mobility History of Wireless Types of Wireless Networks Categories of Wireless Networks Comparison among the types of wireless networks Wireless Spectrum Why go wireless? Ubiquitous computing Benefits of Wireless Networking Applications of Wireless networks Statistics and Trends of Wireless Networks NES440 Wireless Networks 5 What is “Wireless and Mobile Networking”? NES440 Wireless Networks 6 What is Wireless Networking? NES440 Wireless Networks 7 What is Wireless Networking? Enabling people to communicate and access applications and information without wires Information is transmitted using electromagnetic (EM) waves Providing people with the freedom of movement and ability to easily and dynamically extend applications to different parts of a building, city, or anywhere in the world Also called tether-less (or tether-free) communication Characteristics on an EM wave: Travels in the air at the speed of light (c = 3x108 m/s) Has a frequency (f) and wavelength (l) l is the distance occupied by a single cycle of the signal l = c / f Example: for the 2.4GHz Wi-Fi signals, l = 12.5 cm NES440 Wireless Networks 8 What is Mobility? Initially, the Internet and Telephone Networks were designed assuming that the user terminals are stationary. That is: No change of location during a call or connection User terminals access the network always from fixed locations Mobility vs. portability Mobility means changing the point of attachment to the network online (a user property) The user can communicate with anyone, from anywhere, at anytime Portability means changing the point of attachment to the network offline (a device property) The device can be connected to the network from anywhere at anytime NES440 Wireless Networks 9 Degrees of Mobility Walking Users o Low speed o Small roaming area o Usually uses high-bandwidth/low-latency access Vehicles o High speeds o Large roaming area o Usually uses low-bandwidth/high-latency access NES440 Wireless Networks 10 History or Wireless NES440 Wireless Networks 11 Early forms of wireless communications NES440 Wireless Networks 12 Early forms of wireless communications Wireless communication and networking have been around for many years Native Americans waving buffalo skins over a fire to send smoke signals over big distances The use of pulsing lights carrying information through Morse code between ships E.g.; SOS (Save-Our-Ship or Save-Our-Souls) NES440 Wireless Networks 13 History of the Wireless Technologies (1) 1831: Faraday demonstrates electromagnetic induction 1864: Maxwell develops the theory of EM field 1880: Hertz discovered the electromagnetic waves 1896: Guglielmo Marconi First demonstration of wireless telegraphy Built on work of Maxwell and Hertz to send and receive Morse Code (first radio broadcasts were digital!) Based on long wave (>> 1 km), spark transmitter technology, requiring very large, high power transmitters First used by British Army and Navy in the Boer War (first research funding by the military!) 1907: Commercial Trans-Atlantic Wireless Service Huge ground stations: 30×100m antenna masts Beginning of the end for cable-based telegraphy NES440 Wireless Networks 14 History of the Wireless Technologies (2) WW I: Rapid development of communications intelligence, intercept technology, cryptography 1920: Marconi discovers shortwave (<100 m) radio Longwave follow contour of earth Very high transmit power, 200 KW+ Shortwaves reflect, refract, and absorb, like light Bounce off ionosphere Higher frequencies made possible by vacuum tube (1906) Cheaper, smaller, better quality transmitters 1920: First commercial radio broadcast (Pittsburgh) 1921: First Mobile Radio Wireless dispatch system for Detroit Police 1946: First Mobile Telephone Service by AT&T Half-duplex (Push to talk) NES440 Wireless Networks 15 History of the Wireless Technologies (3) 1970: First Cellular Phone Service by AT&T Cell, handoff, and roaming 1971: First Wireless Data Network Aloha at University of Hawaii 1974: FCC allocates 40 MHz for cellular telephony 1982: European GSM and Inmarsat established 1984: Breakup of AT&T 1984: Initial deployment of AMPS cellular system 1990: First Commercial Wireless LAN Product AT&T WaveLAN 1997: First Wireless LAN Standard IEEE 802.11, 2Mbps NES440 Wireless Networks 16 Types of Wireless Networks NES440 Wireless Networks 17 Categories of Wireless Networks Wireless networks are categorized depending on the size of the physical area that they cover. The following categories of wireless networks satisfy diverse user requirements: Wireless Personal-Area Network (WPAN) E.g.; Bluetooth and Zigbee Wireless Local-Area Network (WLAN) E.g.; Wi-Fi Wireless Metropolitan-Area Network (WMAN) E.g.; WiMax Wireless Wide-Area Network (WWAN) E.g.; GPRS NES440 Wireless Networks 18 Another Classification of Wireless Networks Wireless networks can also be classified as: Infrastructure-based Wireless Networks Cellular Networks Wireless LANs Infrastructure-less Wireless Networks Wireless PANs Mobile Ad hoc Networks (MANETs) Wireless Sensor Networks (WSNs) NES440 Wireless Networks 19 Comparison of Wireless Network Types Type Coverage Performance Standards Applications WPAN Within reach Moderate Bluetooth, UWB Cable of a person IEEE 802.15, replacement for and IrDa peripherals WLAN Within a High IEEE 802.11, Mobile extension building or Wi-Fi, of wired networks campus and HiperLAN WMAN Within a city High Proprietary, Fixed wireless of IEEE 802.16, homes and and WiMAX businesses to the Internet WWAN Worldwide Low CDPD and Mobile access to Cellular 2G, the Internet from 2.5G, and 3G outdoor areas NES440 Wireless Networks 20 Comparison of Wireless Technologies (1) NES440 Wireless Networks 21 Comparison of Wireless Technologies (2) NES440 Wireless Networks 22 Wireless Spectrum (1) Broadcast TV • VHF: 54 to 88 MHz, 174 to 216 MHz • UHF: 470 to 806 MHz 30 MHz 300 MHz 3 GHz 30 GHz FM Radio • 88 to 108 MHz Digital TV • 54 to 88 MHz, 174 to 216 MHz, 470 to 806 MHz NES440 Wireless Networks 23 Wireless Spectrum (2) Wireless WAN 3G Broadband Wireless • 746-794 MHz, 1.7-1.85 GHz, 2.5-2.7 GHz 30 MHz 300 MHz 3 GHz 30 GHz Wireless WAN Cellular Phone • 800-900 MHz Wireless WAN Personal Communication Service (PCS) • 1.85-1.99 GHz NES440 Wireless Networks 24 Wireless Spectrum (3) Wireless LAN Wireless LAN (IEEE 802.11b/g) (IEEE 802.11a) • 2.4 GHz • 5 GHz 30 MHz 300 MHz 3 GHz 10 GHz Wireless PAN Wireless MAN (Bluetooth) (WiMAX) • 2.4 GHz • 10-16 GHz NES440 Wireless Networks 25 Why Go Wireless? NES440 Wireless Networks 26 The Need for Wireless and Mobile Networking Demand for Ubiquitous (or Pervasive) Computing Anywhere, anytime computing and communication You don’t have to go to the computer lab to check your email Pushing the computers more into the background Focus on the task and life not on the computer Use computers seamlessly to help you and to make your life much easier Computers should be location-aware Adapt to the current location Discover location-dependent services NES440 Wireless Networks 27 Sample Applications of Ubiquitous Computing You walk into your office and your computer automatically authenticates you through your active badge and logs you into the system You go to a foreign building and your PDA automatically discovers the closest public printer where you can print your documents The technician gets close to a malfunctioning machine in the factory and his tablet PC brings up the diagnostics screen and downloads the engineering drawing and specs of the machines NES440 Wireless Networks 28 Benefits of Wireless Networking Increasing Efficiency and Accuracy Individuals can communicate no matter where they are, within range of communication Team-based workers can access network resources while collaborating in a team environment Easier and less expensive installation: Installing network cabling in older buildings is difficult and costly Wireless networking is an ideal solution Eliminating cabling saves money and time Allows offices to reorganize easily Increased reliability: Eliminates certain types of cable failures Increases overall network reliability NES440 Wireless Networks 29 Application: Efficient Workflow Security Server Machine Controller Access to multiple sources Minimize travel No 2nd party involvement Paperless information entry Status update Auditing Alerts NES440 Wireless Networks 30 Application: Retrofits Wires can be less expensive if they are all run at one time when the facility is built New applications such as maintenance sensing Experimental deployment for process optimization Commissioning new equipment Vibration? Pressure? NES440 Wireless Networks 31 Application: Cable Replacement Moving machinery Festoon cables Reaching great distances SCADA: Supervisory Control And Data Acquisition Crossing electrical and physical barriers NES440 Wireless Networks 32 Statistics and Trends of Wireless Networks NES440 Wireless Networks 33 Worldwide Mobile Subscriber Penetration NES440 Wireless Networks 34 Worldwide Wireless Telecom Spending Forecast Growth Spending ($B) Source: IDC's Worldwide Black Book Query Tool, Version 03, 2010 (IDC #225505, October 2010) Estimated Wireless Subscriber Connections NES440 Wireless Networks 36 Wireless Service Revenue NES440 Wireless Networks