1 / 19

Wireless LAN Technology

Wireless LAN Technology. Introduction. Why look at WLANs? Who Cares? Maybe he hasn’t noticed, but we develop software for a living, not wire up networks…. Topics of Discussion. What is a Wireless LAN How does a WLAN work? Differing Technologies within the implementation of WLANs

ray
Download Presentation

Wireless LAN Technology

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Wireless LAN Technology

  2. Introduction • Why look at WLANs? • Who Cares? • Maybe he hasn’t noticed, but we develop software for a living, not wire up networks…

  3. Topics of Discussion • What is a Wireless LAN • How does a WLAN work? • Differing Technologies within the implementation of WLANs • Advantages/Disadvantages • How do I steal my rich stock broker neighbor’s weekly stock tips?

  4. What is a Wireless LAN • A network of computers and other devices not bound by the normal constraints and costs that a traditional LAN involves

  5. How does a WLAN work? • Data sent through the air using radio frequency • Broken down into two basic components: Transmitter/Transceiver • Transmitters/Transceivers transmit data at the same radio frequency

  6. Transmitters • Access Points(AP) • Network device responsible for converting wired LAN signal into radio frequency • Good for supporting users within a couple of hundred feet without degradation of signal

  7. AP Usability • Up to three Access Points may be combined to create larger field • Automatic strongest field detection allows user to wander around with changeovers staged transparently • If longer range is necessary, directional antennae can be substituted in place of AP

  8. Transceivers • Wireless Ethernet cards • Manufactured for both PCMCIA/PCI slots • Installs just like regular LAN adapters • Be careful for the antennae…

  9. The 802.11/11b Standard • Standard developed for WLAN technologies • Lays out: • FH – Frequency Hopping • DSSS – Direct Sequence Spread Spectrum • Diffused infrared

  10. Frequency Hopping(FH) • Uses Bursts of signals • Maintains a single logical channel • Is one of the two recommended RF platforms found in the 802.11 standard, has been omitted for new 802.11b platform

  11. Direct Sequence Spread Spectrum(DSSS) • Has been adopted in both the 802.11/11b standard • The use of a wider frequency range while sending data allows for higher bandwidth • Breaks up data into small pieces, then transmits through a range of frequencies

  12. Security • RF signals are unfortunately prone to interception by unwanted parties(intentional/unintentional) • FH quickly switches from frequency to frequency making it hard to keep up • DSSS is scrambled, reducing risk of unintentional interception(900 mhz phones, military comm, etc…)

  13. The Big Gun • WEP – Wired Equivalent Privacy • Uses a key on each end, much like an RSA model • This implementation is the answer to a lot of firms crying out for privacy • Allows for Geographically dependent security

  14. Performance • 802.11 used to sustain at most a 6mb/s connection • New 802.11b standard commands closer to 11mb/s • Signal degrades with distance depending primarily on environment(open field vs. lead shielding)

  15. Disadvantages • Limited range(500 ft, up to 1500 with additional AP hardware) • Bandwidth quickly eaten by too many machines(load balancing has not yet fully matured within this technology) • Limited Maximum Bandwidth (11mb/s)

  16. Advantages • Easy, convenient setup • Highly cost effective for small to mid-range shops, or as add-ons to large enterprise networks • Minimal downtime for relocation of computer away from cubicle with annoying person next door

  17. Get Rich Quick Scheme • Now… How to get those stock quotes…

  18. Use a Hidden Web Cam • Or just go ask him, either way, it is substantially easier and cheaper than trying to hack into a wireless LAN using DSSS combined with WEP

  19. Any Questions?

More Related