Wireless LANs December 2011 March 2012 IEEE 802.11 Overview (2) รศ. ดร. อน นต ผลเพ ม Assoc. Prof. Anan Phonphoem, Ph.D. anan.p@ku.ac.th Intelligent Wireless Network Group (IWING Lab) http://iwing.cpe.ku.ac.th Computer Engineering Department Kasetsart University, Bangkok, Thailand 1
Outline IEEE 802 Standards IEEE 802.11 Overview IEEE 802.11 Services History and present of IEEE 802.11 2
IEEE 802.11 Family Standards Band (GHz) Raw Throughput Typical Throughput 802.11 2.4 2 Mbps (Legacy) 1 Mbps 802.11a 5 54 Mbps 20 Mbps 802.11b 2.4 11 Mbps 5 Mbps 802.11g 2.4 54 Mbps 20 Mbps 802.11n 2.4 / 5 300, 600 Mbps 130 Mbps 802.11ac < 6 1 Gbps? 3
IEEE 802.11 Family Task Group Descriptions 802.11c Improves interoperability 802.11d Multiple Regulatory Domains (Improve Roaming; New country) 802.11e Quality of Service (QoS); prioritizing voice or video 802.11f Inter-Access Point Protocol (IAPP) 802.11h Supports measuring and managing the 5-GHz radio signals in 802.11a 802.11i Enhanced Security (repairs WEP weakness) 802.11j Extensions for Japan 802.11k Passing specific radio frequency health and management data to higher-level management apps. 4
IEEE 802.11 Family http://en.wikipedia.org/wiki/ieee_802.11 IEEE 802.11p - WAVE - Wireless Access for the Vehicular Env. (e.g. ambulances and passenger cars) (working - 09?) IEEE 802.11r - Fast roaming (08) IEEE 802.11s - Mesh Networking, Extended Service Set (ESS) IEEE 802.11T - Wireless Performance Prediction (WPP) (cancel?) IEEE 802.11u - Interworking with non-802 networks (for example, cellular) (proposal evaluation - March 2010?) IEEE 802.11v - Wireless network management (early stages - 2010?) IEEE 802.11w - Protected Management Frames (early stages - 2009?) IEEE 802.11y - 3650-3700 MHz Operation in the U.S. (2008) (from 802.11a to 3.7 GHz) IEEE 802.11z: Extensions to Direct Link Setup (DLS) (September 2010) 5
On the way http://en.wikipedia.org/wiki/ieee_802.11 IEEE 802.11aa: Robust streaming of Audio Video Transport Streams (~ March 2012) IEEE 802.11ac: Very High Throughput <6 GHz (~ December 2012) 802.11n improvement better modulation scheme (expected ~10% throughput increase) wider channels (80 or even 160 MHz) multi user MIMO IEEE 802.11ad: Very High Throughput 60 GHz (~ Dec 2012) IEEE 802.11ae: QoS Management (~ Dec 2011) IEEE 802.11af: TV Whitespace (~ Mar 2012) IEEE 802.11ah: Sub 1Ghz (~ July 2013) IEEE 802.11ai: Fast Initial Link Setup (~ Sep 2014) 6
Wireless System Roadmap Intelligent Wireless Network Group (IWING) http://www.dolcera.com/wiki/index.php?title=image:roadmap.jpg CPE Department, Kasetsart University
Other Security QoS Radio History: WLAN Technology Roadmap WLAN standards will emphasize throughput, QoS, security & management Wi-Fi 802.11b 802.11g 802.11a 802.11n Migration to dual-band Faster data rates with.11n WME (edcf) 802.11e VoIP & streaming support WEP 802.1x WPA (TKIP) 802.11i (AES) Strong AES encryption Port-based authentication Past Cisco CCXv1 CCXv2 2004 CCXv3 802.11d 802.11h 802.11k 2005 Cisco interoperability Measurements & regulatory 2006 By Randy Kendzior, Dell, Inc. September 24, 2004 8
WPAN WLAN BWA WWAN Increasing Range and Mobility History: Wireless Technology Roadmap GSM GPRS 115 kbps CDMA2000 1xRTT Wi-Fi 802.11b 11 Mbps 802.11g 802.11a 54 Mbps EDGE 384 kbps 1xEV-DO WCDMA (UMTS) 2 Mbps 802.11n 1xEV-DV 100+ Mbps HSPDA 144 kbps 2.4 Mbps 3.1 Mbps WiMAX 802.16a 2-60 Mbps 802.16e MobileFi 802.20 Bluetooth 1.1 1 Mbps Past Zigbee 802.15.4 Bluetooth 1.2 250 Kbps 2004 Bluetooth Bluetooth EDR 2.x 3 Mbps Zigbee 802.15.4 1 Mbps UWB 802.15.3a 100 Mbps+ 2005 2006 NG UWB 480 Mbps 2007+ By Randy Kendzior, Dell, Inc.September 24, 2004 9
Wireless evolution (2011) http://electronicdesign.com/article/communications/wireless-companies-follow-the-roadmap-past-4g-and-on-.aspx Louis E. Frenzel, June 01, 2011 10
IEEE 802.11 Standards 802.11s Mesh 802.11p WAVE MAC PHY 802.11 ( 99) MAC + 2Mbps PHY 802.11b ( 99) 11 Mbps 2.4GHz PHY 802.11h DFS & TPC 802.11i Security 802.11f Inter AP 802.11a ( 99) 54 Mbps 5GHz PHY 802.11g 54 Mbps 2.4GHz PHY 802.11r Fast Roam 802.11e QoS 802.11k RRM 802.11m Maint 802.11u WIEN SG 802.11v WNM 802.11n High Throughput (>100 Mbps) Current work 802.11T Test Methods CBP SG APF SG Study groups Published By Peng Yan, Tampere University of Technology, 12/4/2005 11
History: 802.11 Legacy 1997: First standard Standard name: IEEE 802.11-1997 Updated: IEEE 802.11-1999 Starting Point for Standard-based WLAN Radio and infrared medium For 2 Mbps: (fallback to 1 Mbps Noisy): Direct sequence Spread Spectrum (DSSS) modulation For 1-2 Mbps Frequency Hopping Spread Spectrum (FHSS) Both DSSS and FHSS operate in ISM band 2.4 GHz 12
802.11b 802.11b-1999 Range 50 100 m. (depends on obstacles) Omni-directional antenna Indoor / Outdoor / Point-to-point (high-gain external antennas) Max throughput of 11 Mbps fallback 5.5, 2 and 1 Mbps 13
802.11b Attenuation: Metal, Thick walls, Water, etc. ISM Band 2.4 GHz DSSS CSMA/CA 14 overlapping channels Different channels for different countries 3 simultaneously channels E.g. 1, 6, and 11 14
802.11b Channels http://www.air-stream.org/channel_802_11b Japan 12 & 13 Not for US 15
802.11a 2001 (802.11a-1999) Max throughput of 54 Mbps Typical throughput around 20 Mbps ISM Band 5 GHz OFDM CSMA/CA 16
802.11a 12 nonoverlapping channels, 8 dedicated to indoor 4 to point to point Not widely deployed (US. / Japan) 802.11b popularity Less range / More attenuation Lack of roll back compatibility (now support a,b,and g) In Europe considering HiperLan2 17
Unlicensed National Information Infrastructure (U-NII) Radio frequency spectrum used by 802.11a devices U-NII Low (U-NII-1) 5.15-5.25 GHz Require use of an integrated antenna Power limited to 50mW U-NII Mid (U-NII-2) 5.25-5.35 GHz Allow for a user-installable antenna (radar avoidance) Power limited to 250mW 18
Unlicensed National Information Infrastructure (U-NII) U-NII Upper (U-NII-3) 5.725 to 5.825 GHz Sometimes referred to as U-NII / ISM due to overlap with the ISM band Allow for a user-installable antenna Power limited to 1W U-NII Worldwide 5.47-5.725 GHz Both outdoor and indoor (radar avoidance) Power limited to 250mW 19
802.11a Channels http://transition.fcc.gov/pshs/techtopics/techtopics10.html 20
802.11g 3 rd quarter 2003 ISM Band 2.4 GHz Max throughput of 54 Mbps (Net 24.7 Mbps) Fully backwards compatible with 802.11b OFDM CSMA/CA 21
802.11g Channels Same as 802.11b http://en.wikipedia.org/wiki/802.11g 22
802.11n Established in Sep 2003 2 Competing Alliances (for the draft 802.11n) Task group n synchronization (TGn Sync) World Wide Spectrum Efficiency (WWiSE) Both agree on the usage of multiple input multiple output (MIMO) antenna technology Mostly differences on channel bandwidth allocation, PHY (OFDM) and MAC Max throughput (MAC SAP) 100 Mbps 23
Status 802.11n June 2007 Draft 2.0 (Official device) Draft N, Pre-N May08 Draft 4.0, Jan09 Draft 7.0, May09 Draft 10.0 (Working) Qualcomm introduces WCN1312 (June 2009) Single-Chip 802.11n Wireless LAN Solution for Handsets and Mobile Devices 2.4 GHz, data rates up to 72 Mbps Data rates up to 600 Mbps Achieved with max of four spatial streams using a 40 MHz-wide channel 24
MIMO MIMO encoder divides 108 Mbps 2 x 54 Mbps Stream One antenna / stream on same radio channel 25
MIMO-OFDM based IEEE802.11n http://www.merl.com/areas/images/adaptation.jpg MCS: modulation and coding schemes 26
Example of Max data rates http://en.wikipedia.org/wiki/802.11n Data rate (Mbit/s) MCS index Spatial streams Modulation type Coding rate 20 MHz channel 40 MHz channel 800 ns GI 400 ns GI 800 ns GI 400 ns GI 0 1 BPSK 1/2 6.50 7.20 13.50 15.00 1 1 QPSK 1/2 13.00 14.40 27.00 30.00 9 2 QPSK 1/2 26.00 28.90 54.00 60.00 10 2 QPSK 3/4 39.00 43.30 81.00 90.00 15 2 64-QAM 5/6 130.00 144.40 270.00 300.00 21 3 64-QAM 2/3 156.00 173.30 324.00 360.00 31 4 64-QAM 5/6 260.00 288.80 540.00 600.00 GI: Guard interval 27
802.11n Channel Bandwidth TGn Sync uses 40 MHz channels in the 5 GHz spectrum, the same one used by 802.11a WWiSE prefers 20 MHz channels in the 2.4 GHz consistently used 802.11b/g spectrum 28
Application Comparison 802.11a/b/g focus on computer networking 802.11n interests on broad communication and entertainment areas Consumer applications like HDTV Streaming video Regular use for today 29
Non-overlapping Channels (2.4 GHz) http://en.wikipedia.org/wiki/list_of_wlan_channels 30
802.11 comparison Family 802.11 802.11b 802.11a 802.11g 802.11n Frequency 2400-2483.5 MHz 2400-2483.5Hz 5150-5250 MHz 5250-5350 MHz 5725-5825 MHz 2400-2483.5 MHz 2.4GHz and 5 GHz Band ISM ISM UNII ISM ISM, UNII Bandwidth 83.5 MHz 83.5 MHz 300 MHz 83.5 MHz Same Allocation Number of Channels FHSS: 79 ch DSSS: 3 or 6 3 12 3 Same as 802.11b/a/g Channel Width 20 MHz 20 MHz 20 MHz 20 MHz 20 MHz or 40MHz Standard year July 1997 Sep. 1999 Sep. 1999 March 2002 started Expected in October 2008 Modified from http://transition.fcc.gov/pshs/techtopics/techtopics10.html 31
802.11 comparison Family 802.11 802.11b 802.11a 802.11g 802.11n Max PHY rate 2 Mbps 11 Mbps 54 Mbps 54 Mbps 144 Mbps Up to 600 Data Throughput Mbps <1.2 Mbps < 5 Mbps < 32 Mbps < 32 Mbps <80Mbps, 11g <160 Mbps, 11a Fall-back 1, 2 1, 2, 5.5, 11 6, 9, 12, 18, 1, 2, 5.5, 11 NG WiFi Data Rate 24, 36, 48, 54 MAC CSMA/CA CSMA/CA CSMA/CA CSMA/CA CSMA/CA Modulation Technology FHSS DSSS DSSS OFDM DSSS OFDM DSSS OFDM/OFDMA With MIMO Max. Power 1000mw 1000mw 50, 250, 1000 mw Same (normal) (30mw) (30mw) 1000mw Modulation BPSK BPSK,QPSK, CCK BPSK, QPSK, 16-64 QAM CCK, QAM Same Modified from http://transition.fcc.gov/pshs/techtopics/techtopics10.html 32
802.11 Wi-Fi Specification defined by IEEE (not compatibility guarantee) A special group, Wi-Fi Alliance Group of manufacturers Test compatibility Guarantee interoperability (by issue Wi-Fi Trademark) Start with 802.11b Dual band/tri mode (a, b, or g) or more n Security standard Wi-Fi Protected Access (WPA) 33
802.11e MAC Enhancements for Quality of Service in the capabilities and efficiency of the protocol VoIP, Video conferencing, Movie, 34
IEEE 802.11i Weakness reports in the WEP Create a larger number of initialization vectors for encryption Dropping WEP2 Change to Temporal Key Integrity Protocol (TKIP) a key retains its security over a period of time Need 802.1x Authenticating method Some weaknesses (man-in-the-middle interception) 35
MeshDynamics Since 2002, www.meshdynamics.com/mdperformanceanalysis.html 36