wlan - 1 Wireless LAN EL536 Principles of Communication...

Info iconThis preview shows pages 1–10. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 1 Wireless LAN EL536: Principles of Communication Networks © Kang Xi, Polytechnic University 2 Overview of Wireless LAN ¡ Main Advantage: ¢ Freedom ¡ Main Challenges: ¢ Shared transmission medium ¢ Transmission impairments EL536: Principles of Communication Networks © Kang Xi, Polytechnic University 3 Infrared, Optics, Radio ¡ Infrared ¢ Huge spectrum, potential high data rate ¢ Line-of-sight ¡ Free space optics ¢ At the speed of light ¢ Line-of-sight ¡ Radio (narrow/wide band) ¢ Real freedom ¢ High speed ¢ Limited frequency resource EL536: Principles of Communication Networks © Kang Xi, Polytechnic University 4 Wireless LAN -- IEEE 802.11 ¡ Replacement for Ethernet: ¢ wireless channel ¢ Frequency band: unlicensed radio spectrum of 2.4GHz and 5GHz ¡ Data rates: ¢ 1, 2, 5.5, 11, 54 Mbps ¡ Range: transmission power up to 100mW ¢ indoor: 20 - 25 meters ¢ outdoor: 50 - 100 meters EL536: Principles of Communication Networks © Kang Xi, Polytechnic University 5 IEEE 802.11 Protocols ¡ IEEE 802.11b: 5, 11Mbps ¡ IEEE 802.11a: 6, 9, 12, 18, 24, 36, 48, 54Mbps ¡ IEEE 802.11g: 54Mbps ¡ IEEE 802.11i: security ¡ IEEE 802.11f: Inter Access Point Protocol ¡ IEEE 802.11e: Quality of Service enhancement EL536: Principles of Communication Networks © Kang Xi, Polytechnic University 6 Basic Service Set (BSS) Architecture ¡ Infrastructure Mode ¢ No direct communication is allowed between stations ¢ An access point (AP) communicate with all the stations and relay messages ¡ Ad Hoc Mode ¢ Peer-to-peer direct communication EL536: Principles of Communication Networks © Kang Xi, Polytechnic University 7 Extended Service Set ESS: a set of BSSs interconnected by a distribution System – ESS and all of its stations appear to be in a single MAC layer – AP communicate with each other to forward traffic – Station mobility within an ESS is invisible to the higher layers EL536: Principles of Communication Networks © Kang Xi, Polytechnic University 8 Example Access Point + Router EL536: Principles of Communication Networks © Kang Xi, Polytechnic University 9 Protocol Stacks 802.3 PHY 802.3 MAC LLC IP 802.11 PHY 802.11 MAC EL536: Principles of Communication Networks...
View Full Document

{[ snackBarMessage ]}

Page1 / 27

wlan - 1 Wireless LAN EL536 Principles of Communication...

This preview shows document pages 1 - 10. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online