Wireless Networks - PDF Free Download

802.11 Wireless Networks Presentation for North Central Regional Meeting October 19, 2010 Tom Jones, PE, RCDD / NTS Field Sales Engineer, D-Link

Agenda Brief History of Wireless Networks 802.11b, 802.11g 802.11a New Features of 802.11n Wireless Site Surveys Wireless Design Legacy, Mixed, and Greenfield Modes PoE and Wireless Access Points Managing the Wireless Network

WLAN Brief History Late 1980s - High Cost, Proprietary 900MHz Systems, 860 Kbps Data Rate, Reliability Low 1992 - IEEE Begins Draft of 802.11 Spec July 1997-802.11 Released, 900MHz or 2.4GHz September 1999-802.11b Ratified, Covers Only DSSS; Reliable IMS Band, 2.4GHz, 11 Mbps - Now a Reasonable Priced Product 1999-802.11a Also Ratified for 54Mb In 5GHz Band, but No Products Available

WLAN Brief History 2001-802.11a Chipsets & Products Become Available 2001-802.11g Draft Spec, Similar il to 802.11b, but Higher Data Rates (54Mb) 2002-802.11i Draft Spec, Stronger Encryption for Wireless Networks 2003-802.11g Ratified in June 2004-802.11i Ratified in June 2006-802.11n Draft Spec Proposed for Higher Speed 2007-802.11n Draft 2.0 Released 2007 - Wi-Fi.org Began Certifying 802.11n Draft 2008 - Virgin America Launches In-Flight Wi-Fi 2009-802.11n Ratified in October

Wireless LAN 802.11 Choices 900MHz vs. 2.4GHz vs. 5GHz 900 MHz ISM 2.4 GHz ISM 5 GHz U-NII PROs IEEE 802.11 Global l Market Global l Market? Greater Range Than 2.4GHz for Internal LANs IEEE 802.11b, g IEEE 802.11a Higher Data Rates Higher Data Rates (11-54 Mbps) (22-54 Mbps) 8 Channels CONs Maximum Data Rate of 1 Mbps Limited Bandwidth Crowded Band Less Range Than 900MHz for Internal LANs Only 3 Channels Less Range Than 900MHz or 2.4GHz Higher Cost RF Components Larger Antenna ISM - Industrial, Scientific, & Medical Band U-NII - Unlicensed National Information Infrastructure Band

IEEE 802.11 Task Groups 802.11a - 5 GHz, 54 Mbps (1999/2001) 802.11b - 2.4 GHz, 11 Mbps (1999) 802.11c - MAC Layer Bridging (Now in 802.1d) 802.11d - Extending 802.11 in Other Countries (2001) 802.11e - Wireless QoS & Packet Bursting (2005) 802.11f - Roaming and Inter-Vendor Access, Inter-Access Point Protocol (2003) (withdrawn 2005) 802.11g - 2.4 GHz, 54 Mbps (2003) 802.11h - Adapt 802.11a for Europe Standards, d Dynamic Frequency Selection (DFS) and Transmit Power Control (TPC) (2004) 802.11i - Enhance 802.11 Security (*formerly part of 802.11e) (2004) 802.11j - 4.9-5.1 GHz Band for Japan (2004) 802.11k - WLAN Radio Resource Measurement 802.11m - Maintenance to Correct Editorial i and Technical Issues of 802.11 802.11n - Proposed (goal: fall 2008) 2.4 GHz and 5GHz, 100Mbps or better 802.11p - Support for mobile (<200 kph) 5 GHz connections up to 1 kilometer 802.11r - Fast roaming support for real-time applications such as VoIP 802.11s - Protocol for auto-configuring paths between APs for multicast, ESS Mesh Networking 802.11t - Performance metrics, measurement methodologies and test conditions 802.11u - Amend 802.11 MAC & PHY to support interworking with external networks 802.11v - Wireless Network Management enhancements 802.11w - Protected Management Frames 802.11y - Contention Based Protocol

802.11b/g In the 2.4GHz Band b or b/g Most Common For Almost a Decade FCC Allocated 11 Channels in USA Use 1, 6, 11 for 3 Non-overlapping Channels Frequency enc Band Crowded with Other Apps Bluetooth Cordless Home Phones & Stereo Earphones Wireless Mice & Keyboards Microwave Ovens

802.11b/g Throughput 802.11g Performance Decreases When 802.11b Devices Enter Network Data Rate (Mbps) Approximate Max Throughput (Mbps) 802.11b 11 6 802.11g (802.11b clients in cell) 54 8 802.11g (no.11b 54 22 clients in cell)

802.11a In the 5 GHz Band Devices Took Longer to Get to Market Faster Speed than 11b, but Less Range More Channels and No Overlap Issues Less Congestion From Other Applications FCC Keeps Changing g Allowed Channels Data Rate (Mbps) Approximate Max Throughput (Mbps) 802.11a 54 25

channel frequency (MHz) United States Europe Japan Singapore China Israel Korea Turkey 40/20 MHz 40/20 MHz 40/20 MHz 10 MHz 20 MHz 20 MHz 20 MHz 20 MHz 20 MHz 183 4915 No No No Yes No No No No No 184 4920 No No Yes Yes No No No No No 185 4925 No No No Yes No No No No No 187 4935 No No No Yes No No No No No 188 4940 No No Yes Yes No No No No No 189 4945 No No No Yes No No No No No 192 4960 No No Yes No No No No No No 196 4980 No No Yes No No No No No No 7 5035 No No No Yes No No No No No 8 5040 No No No Yes No No No No No 9 5045 No No No Yes No No No No No 11 5055 No No No Yes No No No No No 12 5060 No No No No No No No No No 16 5080 No No No No No No No No No 34 5170 No No No No No No Yes Yes Yes 36 5180 Yes Yes Yes No Yes No Yes Yes Yes 38 5190 No No No No No No Yes Yes Yes 40 5200 Yes Yes Yes No Yes No Yes Yes Yes 42 5210 No No No No No No Yes Yes Yes 44 5220 Yes Yes Yes No Yes No Yes Yes Yes 46 5230 No No No No No No Yes Yes Yes 48 5240 Yes Yes Yes No No No Yes Yes Yes 52 5260 Yes Yes Yes No No No Yes Yes Yes 56 5280 Yes Yes Yes No No No Yes Yes Yes 60 5300 Yes Yes Yes No No No Yes Yes Yes 64 5320 Yes Yes Yes No No No Yes Yes Yes 100 5500 Yes Yes Yes No No No No Yes No 104 5520 Yes Yes Yes No No No No Yes No 108 5540 Yes Yes Yes No No No No Yes No 112 5560 Yes Yes Yes No No No No Yes No 116 5580 Yes Yes Yes No No No No Yes No 120 5600 No Yes Yes No No No No Yes No 124 5620 No Yes Yes No No No No Yes No 128 5640 No Yes Yes No No No No Yes No 132 5660 No Yes Yes No No No No No No 136 5680 Yes Yes Yes No No No No No No 140 5700 Yes Yes Yes No No No No No No 149 5745 Yes No No No Yes Yes No Yes Yes 153 5765 Yes No No No Yes Yes No Yes Yes 157 5785 Yes No No No Yes Yes No Yes Yes 12 161 5805 Yes No No No Yes Yes No Yes Yes 165 5825 Yes No No No Yes Yes No Yes Yes

New in 802.11n Standard MIMO 2, 3, or 4 Simultaneous Spatial Streams Maximal Ratio Combining (MRC) Antenna Diversity for MIMO Channel Usage and Channel Bonding 20 MHz channel with 52/56 vs. 48/52 sub-carriers 40 MHz channel with 108/114 sub-carriers Reduced Guard Interval 400 nanosecond vs. 800 nanosecond Transmit Beamforming Smart antenna technology to aim MIMO effect Frame Aggregation Block Acknowledgements (ACKS)

802.11n Certification Wi-Fi Alliance Announced Phased-in Approval of Pre-standard 802.11n Products Certification Based on Draft 2.0 Started In Summer of 2007 Certification Based on Final 802.11 Standard Began In Early 2010 Vendor products certified 802.11n Draft 2.0 will interoperate with the new Wi-Fi CERTIFIED 802.11n products in the same frequency band, even if they use different features

Agenda Brief History of Wireless Networks 802.11b, 802.11g 802.11a New Features of 802.11n Legacy, Mixed, and Greenfield Modes Wireless Site Surveys Wireless Design PoE and Wireless Access Points Managing the Wireless Network

Wireless Network Modes Legacy Mode APs are 802.11n capable, but no 802.11n clients yet 802.11n APs could give slightly better throughput Mixed Mode Mixed environment of 802.11a/b/g/n clients May provide some improvement for a/b/g clients, but 802.11n clients will not see maximum potential Greenfield Mode No legacy support for 802.11a/b/g clients Best throughput for 802.11n clients

Site Survey For Any Wireless Network Design, a Site Survey Is the Only Way to Insure Coverage In All Desired Areas Proper Site Survey Includes Spectrum Analysis and Detailed Report Cannot Be Done Without Proper Tools Site Surveys Must be Done Specifically for the Type of Access Points and Client Devices 802.11a 802.11b/g 802.11n Not a Site Survey if Not Done Properly

Wireless Design Site Survey Is First Step In Good Design Design Must Be Tailored to Wireless Mode Legacy, Mixed, or Greenfield Design Must Be Tailored to Wireless Type(s) 802.11a/b/g/n Just Replacing old APs with 802.11n APs Is Not a Good Design and Will Not Likely Give Best Coverage 802.11n AP Should Be Connected to Gigabit Ethernet Switch

Wireless Design Factors to Consider Should Include: Speed / Throughput Requirements Consider Applications to be Used Consider Expected Number of Users Future Requirements Security Requirements Aesthetic Considerations Environmental Considerations Indoor or Outdoor Plenum Rated or Plastic Case AP Mode or WDS Mode or Both

Thick or Thin Access Points Standalone or Thick APs Individually Configured Roaming Client Must Re-Associate to Next AP Cost Effective for Small Number of APs Managed or Thin Aps Wireless Controller Manages AP Configurations Standalone Controller or Built Into a Switch Seamless Roaming for Client Client Associates with Controller, not AP More oeexpensive einitial ta Cost

Power Over Ethernet 802.3af PoE Standard Provides 48v DC Power Up To 15.4w at the Source Source can be the switch itself or a mid-span power injector Standard maximum power draw at device: 12.95w Be Careful to Look at Overall PoE Power Budget for the Switch Most switches do not provide enough power for full 15.4w on all ports New 802.3at PoE Plus Standard for 25w at the Source

Managing the Wireless Network Two Basic Categories of Access Points Thick AP is standalone and each must be configured Thin AP is pass-through device and configuration is done on a controller that manages multiple APs Some APs can function either way Management Software Can Help with Thick Access Points May support automated firmware upgrade or configuration changes Some third party software packages support products from multiple l vendors

Fully Managed Wireless Network System with Controller(s) and Thin APs Controller May be Separate Box or Built Into a Switch Can Provide Many More Features Automatic channel selection Automatic transmit power settings Fast Roaming capability Captive Portal feature Visual Heat Map Rouge detection and mitigation Wireless Intrusion Detection System (WIDS) Note: WIDS for 802.11n must support both 20 MHz and 40 MHz channels

For More Details This Presentation Was Intended to Only Provide a High Level View of Wireless LAN Features Much More Detail Available in BICSI Wireless Design Reference Manual

Questions? Tom Jones, PE, RCDD / NTS Field Sales Engineer, D-Link Tom.Jones@dlink.com