Student Workbook Presentation Graphics Notes Areas Glossary Presenter Keith R. Parsons, CWNE #3
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802.11n Planning and Optimization Workshop Outline Section I: 802.11 Fundamentals Review of Legacy 802.11a/b/g Section II: 802.11n Concepts, Terms, Features Section III: 802.11n Analysis Section IV: 802.11n Design Section I: 802.11 Fundamentals AirMagnet Product Family Evolution of 802.11 Standards
Comparison of 2.4GHz and 5GHz Radio Waves 2.4GHz Channel Overlap Want Don t Want Don t Care (Signal Strength)
RF Power and Distance So, What *is* an Access Point Anyway? Where 802.11 is in the OSI Model Physical and Data Link
802.11 MAC Header To DS and From DS Bits Diagram MAC Header Frame Details
802.11 classic, b, a, g Available Data Rates Protection Penalty for b/g Mixed Mode Effects of Multipath
Section II: 802.11n Overview 802.11n is Complex! How Detailed do you want to get?
PHY Enhancements Multiple Input, Multiple Output (MIMO) - My Moe
Spatial Division Multiplexing (SDM) Space-Time Block Coding (STBC) Transmit BeamForming (TxBF)
Antenna Selection (ASEL) Short Guard Interval (SGI) Maximum Ratio Combining (MRC)
More Subcarriers Available in 802.11n with 40MHz Channels Forward Error Correction (FEC) 40MHz Channels in the 2.4GHz Band 3 4 5 6 7 8 9 1 6 11 Channel 1 2 3 4 5 6 7 8 9 10 11 12 13 Center Frequency 2412 2417 2422 2427 2432 2437 2442 2447 2452 2457 2462 2467 2472 Channels defined for 2.4 GHz band, showing common 20 MHz channel plan and 40 MHz options
40MHz Channels in the 5GHz Band MAC Layer Enhancements Frame Aggregation
Frame Aggregation Examples Aggregation Analysis
Multiple Traffic ID Block Acknowledgements (MTBA) Power Save Methods Legacy Support Modes
High-Throughput Mode (Greenfield) Legacy Mode HT Mixed Mode L-SIG TxOP Protection
RTS CTS Mode Phase Coexistence Operation (PCO)
Legacy Protection Analysis Modulation and Coding Schemes Granulation and Additional Speeds with 802.11n
HT Informational Element 802.11n Decodes Section III: 802.11n Analysis
New Features of WiFi Analyzer (formally called Laptop Analyzer) New 802.11n Alarms
Affects of Channel Occupancy New Start Columns to Support 802.11 n Fields New 802.11n information in STA and AP detail
802.11n Efficiency Tool 802.11n Analysis Tool
802.11n WLAN Throughput Simulator 802.11n WLAN Throughput Simulator Results
802.11n Tools Device Throughput Calculator (Overhead) Device Throughput Calculator Results
Section IV: 802.11n Design Skills you ll need for 802.11n Deployments Migration Issues New Features of AirMagnet Survey PRO Throughput Simulator 802.11 n Heatmaps Color-coded by 'n' Channel Width Max MCS Operating Mode Measured PHY Data Predictive PHY Data Updated AirWise iperf Survey 'n' Active Survey 'n' Passive Survey Updated Heatmaps
@ 2008 - AirMagnet 9 Updated AirWISE Categories Open Source iperf Throughput Tester
Importance of an Active Survey
802.11n Design Issues Where to go from here? Further Questions?
Glossary 802.11 Groups PHY/MAC Classic 1 & 2 Mbps, 2.4GHz FH, DS, and IR.a PHY up to 54 Mbps in the 5GHz band.b PHY up to 11 Mbps in the 2.4GHz band.c MAC MAC-layer Bridging.d PHY Additional Regulatory Domains for.11b.e MAC Quality of Service (QoS) Improvements.f MAC Inter-Access-Point Protocal IAPP.g PHY Up to 54 Mbps in the 2.4GHz band.h MAC Dynamic Frequency Selection/Transmit Power Control for.11a.i MAC Security Enhancements.j PHY 4.9GHz Regulatory Issues for Japan.k MAC Radio Resource Measurement.m PHY/MAC Maintenance and Technical Corrections.n PHY/MAC Performance and High Throughput - MIMO.p PHY/MAC Wireless Access in Vehicular Environment (WAVE).r MAC Fast Roaming reducing latency during handoffs.s MAC Mesh for both AP and STA.t MAC Testing and Performance Prediction.u MAC Interworking with External Networks.v MAC Network Management.w MAC Management Frame Security.y PHY Operation in the 3650-3700 MHz Band ACK Frame A-MPDU A-MSDU AP ASEL Block ACK BSA BSS CODEC CSD A short frame sent by the receiving station to the transmitting station to confirm the receipt of the frame. Aggregate MAC Protocol Data Unit Aggregate MAC Service Data Unit Access Point Antenna Selection Block Acknowledgement - a method of sending a single Acknowledgement frame to confirm receipt of multiple frames Basic Service Area Basic Service Set Coder/Decoder an algorithm implemented either in software or hardware to encode the digitized voice, video or image for optimum transmission over the network. Cyclic Shift Diversity
CSD ESS FEC Frame Aggregation GI HT HT-GF-STF HT-LTF HT-SFT HT-SIG Interframe Space LDPC L-LTF L-SIG L-STF LTF MCS MIMO MPDU MRC MSDU NAV Non-HT Cyclic Shift Diversity type of Transmit diversity used to spread spatial streams across multiple antennas. Extended Service Set Forward Error Correction a method to help with transmit diversity. A protocol for combining several frames into a single frame, thereby eliminates some inter-frame gaps to improve efficiency on the RF link. Guard Interval a period at the end of each OFDM symbol allocated to letting the signal dissipate prior to transmitting the next symbol to prevent overlap. Legacy devices 802.11 abg use 800ns. High Throughput High Throughput Greenfield Short Training Field High Throughput Long Training Field High Throughput Short Training Field High Throughput Signal Field Is the quiet time between packets transmitted on media Low Density Parity Check Non-HT - Long Training Field Non-HT - Signal Field Non-HT - Short Training Field Long Training Field Modulation Coding Scheme Multiple Input, Multiple Output My Moe MAC Protocol Data Unit Maximum Ratio Combining a technique used by a receiver that is working with two or more diversity antennas to optimally combine signals received taking into account the SNR of each of the received signals. MAC Service Data Unit Network Allocation Vector An indicator used by STA and AP to know time periods when the wireless medium will not be available. NAV information can be derived from announcements in packets concerning how long they intend to occupy the medium. Non-High Throughput legacy devices not capable of 802.11 n communications contained in the HT Information.
Non-HT Duplicate Mode OFDM PCO PSMP RFS RSSI SGI SISO SM STA STBC STBC/SM TPC TxBF WMM A method to protect legacy networks from disruption caused by 802.11 n protocols. Two packets are sent on both halves of the 40MHz channel simultaneously announcing the NAV to tell legacy STA how long to stay off the medium. Orthogonal Frequency Division Multiplexing Phased Coexistence Operation Power Save Multi-Poll Reduced Interframe Spacing Receive Signal Strength Indicator Short Guard Interval an optional use of 400ns GI in the 802.11 n specifications. Single Input, Single Output Spatial Multiplexing Station Client device Space-Time Block Coding Transmitter diversity technique of spreading the signal over multiple antennas to improve reception. STBC also incorporates Forward Error Correction (FEC) coding. Space-Time Block Code/Spatial Multiplexing Transmit Power Control Transmit Beamforming Wireless Multi-Media the WiFi Alliance QoS Protocol for defining different priority levels for Voice, Video, Background and Best Effort Traffic. Based on 802.11e and incorporated in the updated 802.11/2007 edition.
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