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Wireless 2.ppt

  1. 1. WIRELESS LAN Presented by Ching-Man Chong Tracy Tien Johnny Wong Zhong Wei Yu
  3. 3. WIRELESS LAN <ul><li>Introduction </li></ul><ul><li>Wireless Technology </li></ul><ul><li>Wireless LAN </li></ul><ul><li>Configuration </li></ul><ul><li>Differences between wired LAN vs wireless LAN </li></ul><ul><li>Cost-Benefit Study </li></ul><ul><li>Customer Considerations </li></ul>
  4. 4. INTRODUCTION <ul><li>Data communications system </li></ul><ul><li>Alternates wired LAN </li></ul><ul><li>Transmits and receives data over the air </li></ul><ul><li>Minimize the need for wired connections </li></ul><ul><li>Become more popular in general-purpose alternative of business customers. </li></ul><ul><li>Benefited several industries in productivity and mobility </li></ul>
  5. 5. WHY WIRELESS? <ul><li>Advantages: </li></ul><ul><li>MOBILITY </li></ul><ul><li>INSTALLATION </li></ul><ul><li>COST </li></ul><ul><li>SCALABILITY </li></ul>
  6. 6. MOBILITY <ul><li>Real-time information access from anywhere at any time </li></ul><ul><li>Increases productivity and flexibility </li></ul>
  7. 7. INSTALLATION <ul><li>Fast and easy </li></ul><ul><li>No cable needed </li></ul><ul><li>No frustration with wiring </li></ul><ul><li>Go where wires cannot go </li></ul>
  8. 8. COST <ul><li>Short run </li></ul><ul><ul><li>Initial investment is higher than wired LAN </li></ul></ul><ul><li>Long run </li></ul><ul><ul><li>Long-term costs is essentially lower than wired LAN </li></ul></ul><ul><ul><li>Long-term cost and benefits are very important in dynamic and ever-changing business environments </li></ul></ul>
  9. 9. SCALABILITY <ul><li>Can be configured in different topologies to meet the specification of applications and installations </li></ul><ul><li>Can be easily changed from peer-to-peer networks (small # of users) to full infrastructure networks (thousands of users) </li></ul>
  10. 10. IN THE REAL WORLD <ul><li>Not a replacement for the wired infrastructure </li></ul><ul><li>Great complement to what currently exists </li></ul><ul><li>Examples </li></ul><ul><ul><li>Doctors and nurses </li></ul></ul><ul><ul><ul><li>more productive in delivering patients’ information and status instantly </li></ul></ul></ul><ul><ul><li>Student </li></ul></ul><ul><ul><ul><li>access the Internet to consult the catalog of the Library of Congress </li></ul></ul></ul><ul><ul><li>Network managers </li></ul></ul><ul><ul><ul><li>provide backup for mission-critical applications </li></ul></ul></ul>
  11. 11. HOW IT WORKS <ul><li>Use electromagnetic airwaves to communicate information </li></ul><ul><li>Data imposed on radio carrier (radio wave) </li></ul><ul><li>RF electromagnetic wave can easily pass through ordinary wall, it needs to implement with heavy concrete or metal screening. </li></ul>
  13. 13. WIRELESS TECHNOLOGY <ul><li>Satellite-Based System </li></ul><ul><ul><li>Geosynchronous Earth Orbiting (GEO) </li></ul></ul><ul><ul><li>Low Earth Orbiting (LEO) </li></ul></ul><ul><li>Land-Based Network Access System </li></ul><ul><ul><li>Wireless WAN </li></ul></ul><ul><ul><li>Wireless LAN </li></ul></ul>
  14. 14. GEO SATELLITES <ul><li>Circle the earth from a height of 22,300 miles </li></ul><ul><li>3 satellites can be used to provide worldwide coverage </li></ul><ul><li>used for: </li></ul><ul><ul><li>television broadcasts, long distance telecommunications, and various science and military applications </li></ul></ul>
  15. 15. LEO SATELLITES <ul><li>Orbit no higher than 500 miles above the earth </li></ul><ul><li>Travel the earth in a couple of hours </li></ul><ul><li>Multiple satellites needed </li></ul><ul><li>Allow access to very low-power devices </li></ul>
  16. 16. WIRELESS WAN <ul><li>Provide nationwide or citywide coverage </li></ul><ul><li>Example: Ricochet Micro-Cell </li></ul>Source: http://dcs.umd.edu Coverage in Washington D.C., San Francisco, and Seattle
  17. 17. WIRELESS LAN <ul><li>Wireless LAN Topology </li></ul><ul><ul><li>2 main components </li></ul></ul><ul><ul><ul><li>Access Points </li></ul></ul></ul><ul><ul><ul><li>Adapters </li></ul></ul></ul><ul><ul><li>Roaming </li></ul></ul><ul><li>Wireless LAN Technology </li></ul><ul><ul><li>Types </li></ul></ul><ul><ul><li>Standard </li></ul></ul><ul><ul><li>Configuration </li></ul></ul>
  18. 18. ACCESS POINTS <ul><li>Connects to the wired network </li></ul><ul><li>single access point can support a small group of users within a range of several hundred feet </li></ul>Source: http://dcs.umd.edu Wireless Clients Connected to LAN via Access Point
  19. 19. ADAPTERS <ul><li>Users used wireless-LAN adapters to connect to access points </li></ul><ul><li>Implemented as : </li></ul><ul><ul><li>PC cards in notebook computers </li></ul></ul><ul><ul><li>ISA or PCI cards in desktop computers </li></ul></ul><ul><ul><li>Integrated within hand-held computers </li></ul></ul>
  20. 20. ROAMING <ul><li>Each access point can provide between 50,000 to 250,000 square feet of coverage </li></ul><ul><li>Example: Hospital Environment </li></ul>Source: http://dcs.umd.edu
  21. 21. WIRELESS LAN TECHNOLOGY <ul><li>Narrowband Technology </li></ul><ul><li>Spread Spectrum Technology </li></ul><ul><ul><li>Frequency-Hopping Spread Spectrum Technology </li></ul></ul><ul><ul><li>Direct-Sequence Spread Spectrum Technology </li></ul></ul><ul><li>Infrared Technology </li></ul>
  22. 22. NARROWBAND TECHNOLOGY <ul><li>Transmits and receives user information on a specific radio frequency </li></ul><ul><li>keeps the radio signal frequency as narrow as possible </li></ul><ul><li>Radio receiver filters out all radio signals except the ones on its designated frequency </li></ul><ul><li>Example: private telephone lines </li></ul>
  23. 23. SPREAD SPECTRUM TECHNOLOGY <ul><li>Mostly used in wireless LAN system </li></ul><ul><li>Trades of bandwidth efficiency for reliability, integrity, and security </li></ul><ul><li>Signal looks like background noise if not turned to the right frequency </li></ul>
  24. 24. FREQUENCY-HOPPING SPREAD SPECTRUM TECHNOLOGY <ul><li>Uses a narrowband carrier that changes frequency in a pattern known to both transmitter and receiver </li></ul><ul><li>Maintain a single logical channel </li></ul>
  25. 25. FREQUENCY-HOPPING SPREAD SPRECTRUM TECHNOLOGY (con’t) Source: www.wlana.com
  26. 26. DIRECT-SEQUENCE SPREAD SPECTRUM TECHNOLOGY <ul><li>Generates a redundant bit (chip) pattern for each bit to be transmitted </li></ul><ul><li>The longer the chip, the greater the probability that the original data can be recovered </li></ul><ul><li>To unintended receivers: </li></ul><ul><ul><li>Viewed as low-power wideband noise </li></ul></ul><ul><ul><li>Rejected by most narrowband receivers </li></ul></ul>
  27. 27. DIRECT-SEQUENCE SPREAD SPECTRUM TECHNOLOGY (con’t) Source: www.wlana.com
  28. 28. INFRARED (IR) TECHNOLOGY <ul><li>Little used in commercial wireless LANs </li></ul><ul><li>Use very high frequencies </li></ul><ul><li>Inexpensive, but provide very limited range (3ft) </li></ul><ul><li>Typically used for personal area networks </li></ul><ul><li>Used only to implement fixed subnetworks </li></ul>
  29. 29. WIRELESS STANDARD <ul><li>IEEE 802.11 </li></ul><ul><ul><li>represent the 1st standard for wireless LAN </li></ul></ul><ul><ul><li>standardize radio equipment and networks operating system for wireless LAN </li></ul></ul><ul><ul><li>Addresses for: </li></ul></ul><ul><ul><ul><li>Physical (PHY) layer </li></ul></ul></ul><ul><ul><ul><li>Media Access Control (MAC) </li></ul></ul></ul>
  30. 30. CONFIGURATION <ul><li>Peer-to-peer network </li></ul><ul><li>Client and Access point </li></ul><ul><li>Multiple access points and roaming </li></ul><ul><li>Using an extension point </li></ul><ul><li>Using directional antennas </li></ul>
  31. 31. PEER-TO-PEER NETWORK <ul><li>Wireless adapter cards </li></ul><ul><ul><li>Connect 2 PCs </li></ul></ul><ul><li>Client access only to each other, not with a central server </li></ul>Source: http://www.proxim.com
  32. 32. CLIENT & ACCESS POINT (AP) <ul><li>Access point </li></ul><ul><ul><li>Must be wired to the network </li></ul></ul><ul><ul><li>Extend the range of the network </li></ul></ul><ul><ul><li>Allow access from client-to-server and among each workstation </li></ul></ul><ul><ul><li>Real-world: each Access Point can accommodate from 15-50 client devices </li></ul></ul>Source: http://www.proxim.com
  33. 33. MULPTIPLE AP & ROAMING <ul><li>In large facility, more than one AP might be needed to coverage the whole area </li></ul><ul><li>Access Point range: </li></ul><ul><ul><li>Indoor = 500 ft; Outdoor = 1,000 ft </li></ul></ul>Source: http://www.proxim.com
  34. 34. EXTENTION POINT (EP) <ul><li>EP can be connected to the network without wiring. </li></ul><ul><li>EP extend the range of the network by relaying signals from a client to an AP or another EP. </li></ul>Source: http://www.proxim.com
  35. 35. DIRECTIONAL ANTENNAS <ul><li>Extend the wireless networks between buildings </li></ul><ul><li>Antenna must be connected to an AP of the network </li></ul>Source: http://www.proxim.com
  37. 37. MEDIUM ACCESS CONTROL <ul><li>A collision may occur when 2 stations transmit data simultaneously </li></ul><ul><li>Detects the collision and ignores the message </li></ul><ul><li>Each station that wants to transmit waits a random amount of time and then attempts to transmit again </li></ul><ul><li>The random transmission delays reduce the probability that the stations will transmit simultaneously again. </li></ul>
  39. 39. WIRED vs. WIRELESS LAN <ul><li>Wired </li></ul><ul><ul><li>Link clients, printers, and network equipment using cables </li></ul></ul><ul><li>Wireless </li></ul><ul><ul><li>Basic building block is the Cell </li></ul></ul>Source: www.breezecom.com WIRED WIRELESS
  40. 40. WIRE vs. WIRELESS (con’t) <ul><li>Bridging </li></ul><ul><ul><li>Wired </li></ul></ul><ul><ul><ul><li>Access point connects to the backbone of a wired Ethernet LAN via a simple cable </li></ul></ul></ul><ul><ul><li>Wireless </li></ul></ul><ul><ul><ul><li>can be mounted back-to-back with an access point </li></ul></ul></ul><ul><ul><ul><li>Able to link buildings that are miles apart </li></ul></ul></ul>Source: www.breezecom.com
  41. 41. WIRED vs. WIRELESS (con’t) <ul><li>Cells </li></ul><ul><ul><li>Linked Cells (Wired) </li></ul></ul><ul><ul><ul><li>user can walk from Cell A to overlap Cell B without interrupting a work session </li></ul></ul></ul><ul><ul><li>Multi-cells (Wireless) </li></ul></ul><ul><ul><ul><li>Position Access Points at different locations in the coverage areas with their directional antennas </li></ul></ul></ul>Source: www.breezecom.com
  43. 43. WHEN? <ul><li>When you truly need mobility </li></ul><ul><li>When you plan to move or remodel soon </li></ul><ul><li>When set up a portable buildings for temporary use </li></ul><ul><li>When you don’t have time to configure and maintain a wiring scheme </li></ul><ul><li>When running cable is too expensive </li></ul>
  44. 44. Cost-Benefit Study
  45. 45. COST-BENEFIT STUDY <ul><li>89% successful implementation </li></ul><ul><li>92% of respondents believe the definite economic and business benefit after installation </li></ul><ul><li>92% continue to deploy wireless technology in their network </li></ul><ul><li>Payback was less than 1 year across all industries surveyed. </li></ul>Source: www.wlana.com
  46. 46. COST/BENEFIT STUDY (con’t) <ul><li>Economic Benefits </li></ul><ul><ul><li>Payback </li></ul></ul>Source: www.wlana.com
  47. 47. COST/BENEFIT STUDY (con’t) <ul><li>Broad cross-section of the representative industries with successful implementation of wireless LAN </li></ul><ul><ul><li>Education: 23% </li></ul></ul><ul><ul><li>Healthcare: 23% </li></ul></ul><ul><ul><li>Manufacturing/Warehouse: 21% </li></ul></ul><ul><ul><li>Retail: 15% </li></ul></ul><ul><ul><li>Financial/Office Automation: 18% </li></ul></ul>Source: www.wlana.com
  48. 48. Wireless LAN Market
  49. 49. WIRELESS LAN MARKET <ul><li>Customer considerations </li></ul><ul><ul><li>Range and coverage </li></ul></ul><ul><ul><li>Throughput </li></ul></ul><ul><ul><li>Compatibility </li></ul></ul><ul><ul><li>Interoperability </li></ul></ul><ul><ul><li>Interference and Coexistence </li></ul></ul><ul><ul><li>Licensing issues </li></ul></ul><ul><ul><li>Simplicity </li></ul></ul><ul><ul><li>Security </li></ul></ul><ul><ul><li>Cost </li></ul></ul><ul><ul><li>Major vendors </li></ul></ul><ul><ul><li>Scalability </li></ul></ul>
  50. 50. Customer Considerations
  51. 51. CUSTOMER CONSIDERATIONS <ul><li>Range and coverage </li></ul><ul><ul><li>Mostly use Radio Frequency because it can penetrate most indoor walls and obstacles </li></ul></ul><ul><ul><li>Range varies from under 100 feet to more than 300 feet </li></ul></ul><ul><ul><li>Coverage can be extended </li></ul></ul>
  52. 52. CUSTOMER CONSIDERATIONS (con’t) <ul><li>Throughput </li></ul><ul><ul><li>Actual throughput is product and set-up dependent </li></ul></ul><ul><ul><li>Affecting factors: </li></ul></ul><ul><ul><ul><li># of users </li></ul></ul></ul><ul><ul><ul><li>Range and multipath </li></ul></ul></ul><ul><ul><ul><li>Type of wireless LAN system used </li></ul></ul></ul>
  53. 53. CUSTOMER CONSIDERATIONS (con’t) <ul><li>Compatibility with existing network </li></ul><ul><ul><li>Most wireless LANs provide industry-standard interconnection with wired networks such as Ethernet or Token Ring. </li></ul></ul><ul><ul><li>Wireless LAN nodes are supported by network operating systems through uses of appropriate drivers. </li></ul></ul>
  54. 54. CUSTOMER CONSIDERATIONS (con’t) <ul><li>Interoperability of wireless devices </li></ul><ul><ul><li>Different vendors might not be interoperable </li></ul></ul><ul><ul><ul><li>Three reasons </li></ul></ul></ul><ul><ul><ul><ul><li>System based on spread spectrum frequency hopping (FHSS) will not communicate with direct sequence (DSSS). </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Different frequency bands will not interoperate even with same technology. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Differences in implementation. </li></ul></ul></ul></ul>
  55. 55. CUSTOMER CONSIDERATIONS (con’t) <ul><li>Interferences and Coexistence </li></ul><ul><ul><li>Unlicensed wireless transmitting energy in same frequency spectrum can provide interference. (ex. Microwave oven) </li></ul></ul><ul><ul><li>Co-location of multiple wireless LANs: more wireless LANs, more interferences. </li></ul></ul>
  56. 56. CUSTOMER CONSIDERATIONS (con’t) <ul><li>Licensing </li></ul><ul><ul><li>Federal Communications Commission (FCC) </li></ul></ul><ul><ul><li>Wireless LANs operate in portions of radio spectrum: end user does not require license. </li></ul></ul><ul><ul><li>Manufacturer must ensure certification by agency in that country to distribute the use of wireless LANs. </li></ul></ul><ul><ul><li>In US: broadcast over ISM (Instrumentation, Scientific, and Medical) bands. </li></ul></ul><ul><ul><ul><li>Bands: 902-928MHz, 2.4-2.483 GHz, 5.15-5.35 GHz, 5.725-5.875 GHz. </li></ul></ul></ul>
  57. 57. CUSTOMER CONSIDERATIONS (con’t) <ul><li>Simplicity </li></ul><ul><ul><li>Wireless is transparent to users. </li></ul></ul><ul><ul><li>Applications is same with wired LANs. </li></ul></ul><ul><ul><li>Only access points is require cabling. </li></ul></ul><ul><ul><li>Portable from place to place after configured. </li></ul></ul>
  58. 58. CUSTOMER CONSIDERATIONS (con’t) <ul><li>Security </li></ul><ul><ul><li>Complex encryption techniques is used. </li></ul></ul><ul><ul><li>Individual nodes must be security enable before they are allowed to participate in network traffic. </li></ul></ul>
  59. 59. CUSTOMER CONSIDERATIONS (con’t) <ul><li>Cost </li></ul><ul><ul><li>Infrastructure costs </li></ul></ul><ul><ul><ul><li>Wireless access points. </li></ul></ul></ul><ul><ul><ul><li>Number of access points deployed ($1,000 to $2,000). </li></ul></ul></ul><ul><ul><ul><li>Coverage region/type of users serviced. </li></ul></ul></ul><ul><ul><li>User costs </li></ul></ul><ul><ul><ul><li>Wireless LAN adapters. </li></ul></ul></ul><ul><ul><ul><li>Price range from $300 to $1,000. </li></ul></ul></ul>
  60. 60. CUSTOMER CONSIDERTAIONS (con’t) <ul><li>Cost of Installation and Maintenance </li></ul><ul><ul><li>Lower direct cost </li></ul></ul><ul><ul><ul><li>Eliminates direct costs of cabling, labor associated with installing and repair. </li></ul></ul></ul><ul><ul><li>Lower indirect cost </li></ul></ul><ul><ul><ul><li>Reduce indirect costs of user downtime and administrative overhead as it simplify moves, adds, and changes </li></ul></ul></ul>
  61. 61. CUSTOMER CONSIDERATIONS (con’t) <ul><li>MAJOR VENDORS </li></ul><ul><ul><li>6 major vendors for the wireless LAN </li></ul></ul><ul><ul><ul><li>Aironet </li></ul></ul></ul><ul><ul><ul><li>AMD </li></ul></ul></ul><ul><ul><ul><li>Digital Equipment Corporation </li></ul></ul></ul><ul><ul><ul><li>Harris Semiconductor </li></ul></ul></ul><ul><ul><ul><li>Intermec Technologies Corporation </li></ul></ul></ul><ul><ul><ul><li>Lucent Technologies </li></ul></ul></ul>
  62. 62. CUSTOMER CONSIDERATIONS (con’t) <ul><li>Scalability </li></ul><ul><ul><li>Adding access points: to extend coverage. </li></ul></ul>
  63. 63. SUMMARY OF THE PROJECT <ul><li>More to discover about wireless LAN </li></ul><ul><li>Wireless is very popular and exciting </li></ul><ul><li>Much knowledge was gained through this project </li></ul>
  64. 64. References <ul><li>dcs.umd.edu/telecom/library/paper.html </li></ul><ul><li>www.biz.uiowa.edu </li></ul><ul><li>www.blackbox.com </li></ul><ul><li>www.breezecom.com/TechSupport/brztov.htm </li></ul><ul><li>www.geocities.com/CapeCanaveral/Orbit/2694/wlanl.htm </li></ul><ul><li>www.k12.hi.us.htm </li></ul><ul><li>www.proxim.com </li></ul><ul><li>www.wirelesslan.com </li></ul><ul><li>www. wlana .com </li></ul>
  65. 65. Take Me Home
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