Wireless lan duver oquendo

473 views
353 views

Published on

estas diapositivas muestran mejor como poder entender las nuevas tegnologias que nos traen día tras día las telecomunicaciones

Published in: Education, Business, Technology
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
473
On SlideShare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
8
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Wireless lan duver oquendo

  1. 1. INSTITUCION UNIVERSITARIA DE ENVIGADO Tecnología en Gestión de Redes 2012-1 31/08/2012
  2. 2. Wireless LAN
  3. 3. What Are Wireless LANs?They ARE: They ARE NOT:• Local, not wide area • Cellular phones• In-building or campus area • Pagers coverage • PCS• Up to several kilometers for point-to-point (LAN to LAN)• Radio or infrared• Mincomunicaciones licenses not required (ICM bands)• Customer owns the equipment (no usage charges)
  4. 4. ISM (ICM) UnlicensedFrequency Bands Short Wave Radio FM Broadcast AM Broadcast Television Infrared wireless LAN Audio Cellular (840MHz) NPCS (1.9GHz) Extremely Very Low Medium High Very Ultra Super Infrared Visible Ultra- X-Rays Low Low High High High Light violet 5 GHz 2.4 – 2.4835 GHz 902-928 MHz (IEEE 802.11) 83.5 MHz 26 MHz HyperLAN (IEEE 802.11) HyperLAN2
  5. 5. 900MHz v.s. 2.4GHz v.s. 5GHz 900MHz band 2.4GHz band 5GHz band Global market Global market Greater range than 2.4 GHz band ( for in- IEEE 802.11 IEEE 802.11PROs building LANs) Higher data rates Higher data rates (10+Mbps) (20+Mbps) Maximum data Much less Range rate than 900MHz or 1 Mbps Less range than 2.4GHzCONs 900 MHz (for in- Higher cost RF Limited building LANs) bandwidth components Crowded band Small objects interference
  6. 6. IEEE 802.11
  7. 7. Spread Spectrum ApproachesDirect Sequence Frequency Hopping 100 Mw Mhz P O W 1 Sec E R 1 Mw Mhz 1 Ms 222.402 GHz FREQUENCY 2.483 GHz Both technologies are viable.
  8. 8. DS Spread Spectrum
  9. 9. Channels- 802.11 DS Channel 1 2 3 4 5 6 7 8 9 10 11 10 5 9 4 3 8 2 7 1 6 11 2400 2441 2483 Frequency (11) 22 MHz wide stationary channels X “chips per bit” means each bit sent redundantly 11Mbps data rate 3 non-overlapping channels 3 Access Points can occupy same area
  10. 10. Frequency Hopping SpreadSpectrum
  11. 11. Frequency Hopping• 79 channels, 1MHz 9 each 8• Changes frequency 7 (hops) at least every 6 Time 0.4 seconds 5 4• Synchronized hopping 3 required 2 1 2.400 GHz 2.483 GHz Frequency
  12. 12. DS v.s. FH: A Summary on Interference Handling2.4835 GHz 2.4835 GHz Frequency Hopping Direct Sequence Channel 11 3 Frequency Frequency Channel 6 2 2.400 GHz 2.400 GHz Channel 1 1 Time FH system hops around Data may be decoded interference from redundant bits Lost packets are re- Can move to an alternate transmitted channel on next hop to avoid interference
  13. 13. Wireless “Ad Hoc” Network
  14. 14. Local Area Network (LAN) Wireless LAN (WLAN) as an extension to wired LAN Hub Hub Access PointServer Switch Internet Work Group Bridge
  15. 15. Access Point
  16. 16. Antennas
  17. 17. Radiation Pattern
  18. 18. Access Point Coverage 1Mbps DSSS 2Mbps DSSS 5.5Mbps DSSS 11Mbps DSSS
  19. 19. Channel Setup Site Survey Channel ExampleChannel 1 Channel 11 Channel 6 Channel 11 Channel 6Channel 6 Channel 1 Channel 11 Channel 1 Channel 11
  20. 20. RF BarriersRF Barrier Attenuation ExampleAir minimumWood Low PartitionsPlaster Low Office partitionsSynthetic Material Low Office patitionsGlass Low WindowsWater Medium Damp wood, aquariumBricks Medium WallsMarble Medium WallsPaper High Paper rollsConcrete High Floors / WallsMetal Very High Desk / partitions / elevator
  21. 21. Outdoor Wireless Bridges:Applications Companies •Connect buildings on corporate campus •Cheaper than E1 (fast ROI) •Cheaper than fiber •Backup system for when cables get cut Education •Public school system sharing WAN link •Colleges expanding into leased facilities •Connecting temporary classrooms Municipal governments •Connect police, fire, city hall •Public transportation (e.g. buses, metro cars, cable cabins) Temporary broadband link •Construction sites •Outdoor events
  22. 22. Interbuilding BridgesWireless LAN-to-LAN • Wire line bypass • Up to 54Mbps • Faster than E1 • Line-of-sight up to 40 kms • Point-to-Point OR • Point-to-Multipoint • Supports Repeaters Cost effective alternative to leased line/E1 Rapid, simple deployment and re-deployment No government license required
  23. 23. Point-to-Point Configuration Building A Building BDirectional DirectionalAntenna Antenna 0 to 40 kms Bridge (Line of Sight) Ethernet
  24. 24. Point-to-MultipointConfiguration Ethernet Building A Bridge Omni-Directional Antenna Building B Building C Directional Antenna Bridge Bridge Ethernet Ethernet
  25. 25. WLAN “Alphabet Soup”:IEEE 802.11 Standards Activities 802.11a: 5 GHz, 54 Mbps 802.11b: 2.4 GHz, 11 Mbps 802.11d: Multiple regulatory domains 802.11e: Quality of Service (QoS) 802.11f: Inter-Access Point Protocol (IAPP) 802.11g: 2.4 GHz, 54 Mbps 802.11h: Dynamic Frequency Selection (DFS) and Transmit Power Control (TPC) 802.11i: Security 802.11k: Measurement
  26. 26. WECA www.wirelessethernet.org WECA certifies Interoperability between products. This provides assurance to customers of migration and integration options. Several Vendors are members of WECA. Certified products can be found at www.wi-fi.com
  27. 27. WLAN Speeds & Frequencies 802.11g 2.4 GHz – OFDM/CCK 54 Mbps 802.11a 5 GHz – OFDM 54 Mbps 802.11b 2.4 GHz – CCK 11 MbpsProprietary  IEEE 802.11a/b Ratified Jan’99 Jan’00 Jan’01 Jan’02 Jan’03 Jan’04
  28. 28. 802.11a Data rates supported: 54, 48, 36, 24, 12, and 6 Mbps •Client will automatically “downshift” to lower data rate when it gets further from AP 5 GHz band has more channels than 2.4 GHz band •UNII-1 + UNII-2 = 8 channels (vs. 3 channels for 2.4 GHz) •However, depending on distance between APs, you may only be able to use half of the 5 GHz channels due to adjacent channel interference 5 GHz band subject to less interference than 2.4 GHz band •However, 2.4 GHz interference not a major problem in most business environments
  29. 29. BW vs Distance
  30. 30. 802.11g 2.4 GHz, up to 54 Mbps, Full forward/backward compatibility with 802.11b
  31. 31. Wireless Technologies WAN (Wide Area Network) MAN (Metropolitan Area Network) LAN (Local Area Network) PAN (Personal Area Network) PAN LAN MAN WAN 802.11 802.11 GSM, GPRS,Standards Bluetooth HiperLAN2 MMDS, LMDS CDMA, 2.5-3GSpeed < 1Mbps 11 to 54 Mbps 11 to 100+ Mbps 10 to 384KbpsRange Short Medium Medium-Long Long Peer-to-Peer Enterprise T1 replacement, Mobile Phones,Applications Device-to-Device networks last mile access cellular data
  32. 32. IEEE WLAN Standandards
  33. 33. IEEE 802.11 vs HiperLAN 2
  34. 34. Sitios de Interés www.wlana.org www.wirelessethernet.org www.cwne.com www.54g.org www.hiperlan2.com

×