802.11 Wireless Networks - bicsi.org · 802.11 Wireless Networks ... IEEE 802 11 Gl b l M k t Gl b l M k t? ... • For Any Wireless Network Design, a Site Survey Is the

802.11 Wireless Networks

Presentation forNorth Central Regional Meeting

October 19, 2010

Tom Jones, PE, RCDD / NTS

Field Sales Engineer, D-Link

AgendaAgenda• Brief History of Wireless Networks• 802.11b, 802.11g• 802.11a• New Features of 802.11n • Wireless Site Surveysy• Wireless Design• Legacy, Mixed, and Greenfield ModesLegacy, Mixed, and Greenfield Modes• PoE and Wireless Access Points• Managing the Wireless NetworkManaging the Wireless Network

WLAN Brief HistoryWLAN Brief History• Late 1980s - High Cost, Proprietary 900MHz Systems,

860 Kb D t R t R li bilit L860 Kbps Data Rate, Reliability Low• 1992 - IEEE Begins Draft of 802.11 Spec• July 1997 802 11 Released 900MHz or 2 4GHz• 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 Availablebut No Products Available

WLAN Brief HistoryWLAN Brief History• 2001 - 802.11a Chipsets & Products Become Available

2001 802 11 D ft S Si il t 802 11b b t• 2001 - 802.11g Draft Spec, Similar to 802.11b, but Higher Data Rates (54Mb)

• 2002 - 802.11i Draft Spec, Stronger Encryption for p g ypWireless Networks

• 2003 - 802.11g Ratified in June• 2004 802 11i 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• 2009 - 802.11n Ratified in October

Wireless LAN 802 11 ChoicesWireless LAN 802.11 Choices• 900MHz vs. 2.4GHz vs. 5GHz

900 MHz

ISM

2.4 GHz

ISM

5 GHz

U-NII

IEEE 802 11 Gl b l M k t Gl b l M k t?

PROs

•IEEE 802.11

•Greater Range Than 2.4GHz for Internal LANs

•Global Market

•IEEE 802.11b, g

•Higher Data Rates (11-54 Mbps)

•Global Market?

•IEEE 802.11a

•Higher Data Rates (22-54 Mbps)( p ) ( p )

•8 Channels

•Maximum Data Rate of 1 Mbps

•Less Range Than 900MHz for

•Less Range Than 900MHz or 2.4GHz

CONs •Limited Bandwidth

•Crowded Band

Internal LANs

•Only 3 Channels•Higher Cost RF Components

•Larger Antenna

ISM - Industrial, Scientific, & Medical Band U-NII - Unlicensed National Information Infrastructure Band

IEEE 802 11 Task GroupsIEEE 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)• 802.11c - 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 Ad t 802 11 f E St d d D i F S l ti (DFS) d T it P C t l• 802.11h - Adapt 802.11a for Europe Standards, 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 11 M i t t C t Edit i l d T h i l I f 802 11• 802.11m - Maintenance to Correct Editorial 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

f• 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 Band802.11b/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

Freq enc Band Cro ded ith Other Apps• Frequency Band Crowded with Other Apps– Bluetooth– Cordless Home Phones & Stereo Earphones– Wireless Mice & Keyboards– Microwave Ovens

802 11b/g Throughput802.11b/g Throughput• 802.11g Performance Decreases When 802.11b

Devices Enter Network

Approximate Max Data Rate (Mbps)

Approximate Max Throughput

(Mbps)

802 11b802.11b 11 6802.11g (802.11b clients in cell)

54 8clients in cell)

802.11g (no .11b clients in cell)

54 22


802 11a In the 5 GHz Band802.11a 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 Allowed Channelsp g g

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 MHz183 4915 No No No Yes No No No No No184 4920 No No Yes Yes No No No No No185 4925 No No No Yes No No No No No187 4935 No No No Yes No No No No No188 4940 No No Yes Yes No No No No No189 4945 No No No Yes No No No No No192 4960 No No Yes No No No No No No196 4980 No No Yes No No No No No No7 5035 No No No Yes No No No No No8 5040 No No No Yes No No No No No8 5040 No No No Yes No No No No No9 5045 No No No Yes No No No No No11 5055 No No No Yes No No No No No12 5060 No No No No No No No No No16 5080 No No No No No No No No No34 5170 No No No No No No Yes Yes Yes36 5180 Yes Yes Yes No Yes No Yes Yes Yes38 5190 No No No No No No Yes Yes Yes40 5200 Yes Yes Yes No Yes No Yes Yes Yes42 5210 No No No No No No Yes Yes Yes44 5220 Yes Yes Yes No Yes No Yes Yes Yes46 5230 No No No No No No Yes Yes Yes48 5240 Yes Yes Yes No No No Yes Yes Yes52 5260 Yes Yes Yes No No No Yes Yes Yes52 5260 Yes Yes Yes No No No Yes Yes Yes56 5280 Yes Yes Yes No No No Yes Yes Yes60 5300 Yes Yes Yes No No No Yes Yes Yes64 5320 Yes Yes Yes No No No Yes Yes Yes100 5500 Yes Yes Yes No No No No Yes No104 5520 Yes Yes Yes No No No No Yes No108 5540 Yes Yes Yes No No No No Yes No112 5560 Yes Yes Yes No No No No Yes No116 5580 Yes Yes Yes No No No No Yes No120 5600 No Yes Yes No No No No Yes No124 5620 No Yes Yes No No No No Yes No128 5640 No Yes Yes No No No No Yes No132 5660 No Yes Yes No No No No No No136 5680 Yes Yes Yes No No No No No No

•12

136 5680 Yes Yes Yes No No No No No No140 5700 Yes Yes Yes No No No No No No149 5745 Yes No No No Yes Yes No Yes Yes153 5765 Yes No No No Yes Yes No Yes Yes157 5785 Yes No No No Yes Yes No Yes Yes161 5805 Yes No No No Yes Yes No Yes Yes165 5825 Yes No No No Yes Yes No Yes Yes


New in 802 11n StandardNew in 802.11n Standard• MIMO

2 3 or 4 Simultaneous Spatial Streams– 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 effectgy

• Frame Aggregation• Block Acknowledgements (ACKS)

802 11n Certification802.11n 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

B I E l 2010Began In Early 2010• “Vendor products certified 802.11n Draft 2.0 …

ill interoperate ith the ne Wi Fi CERTIFIEDwill interoperate with the new Wi-Fi CERTIFIED 802.11n products in the same frequency band, even if they use different features”even if they use different features

AgendaAgenda• Brief History of Wireless Networks• 802.11b, 802.11g• 802.11a• New Features of 802.11n • Legacy, Mixed, and Greenfield Modesg y, ,• Wireless Site Surveys• Wireless DesignWireless Design• PoE and Wireless Access Points• Managing the Wireless NetworkManaging the Wireless Network

Wireless Network ModesWireless 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

M id i t f /b/ li t b t– May provide some improvement for a/b/g clients, but 802.11n clients will not see maximum potential

• Greenfield Mode• Greenfield Mode– No legacy support for 802.11a/b/g clients– Best throughput for 802.11n clientsest t oug put o 80 c e ts


Site SurveySite Survey• For Any Wireless Network Design, a Site Survey Is the

O l W t I C I All D i d AOnly Way to Insure Coverage In All Desired Areas• Proper Site Survey Includes Spectrum Analysis and

Detailed ReportDetailed 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/g802.11b/g– 802.11n

• Not a Site Survey if Not Done Properly


Wireless DesignWireless 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 CCoverage

• 802.11n AP Should Be Connected to Gigabit Ethernet SwitchEthernet Switch

Wireless DesignWireless Design• Factors to Consider Should Include:

– Speed / Throughput RequirementsConsider Applications to be UsedConsider Expected Number of UsersConsider Expected Number of Users

– Future Requirements– Security Requirementsy q– Aesthetic Considerations– Environmental Considerations

Indoor or OutdoorPlenum Rated or Plastic Case

– AP Mode or WDS Mode or Both– AP Mode or WDS Mode or Both

Thick or Thin Access PointsThick 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 ApsWi l C t ll M AP C fi ti– Wireless Controller Manages AP Configurations

Standalone Controller or Built Into a SwitchSeamless Roaming for Client– Seamless Roaming for Client

Client Associates with Controller, not AP– More Expensive Initial Costo e pe s e t a Cost


Power Over EthernetPower 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

injectorinjector– Standard maximum power draw at device: 12.95w

• Be Careful to Look at Overall PoE Power Budget• Be Careful to Look at Overall PoE Power Budget for the Switch– Most switches do not provide enough power for fullMost 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 NetworkManaging 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 APsdone on a controller that manages multiple APs– Some APs can function either way

• Management Software Can Help with Thick• Management Software Can Help with Thick Access Points– May support automated firmware upgrade orMay support automated firmware upgrade or

configuration changes– Some third party software packages support products

f lti l dfrom multiple vendors

Fully Managed Wireless NetworkFully 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 channel selection– Automatic transmit power settings– Fast Roaming capability– Captive Portal feature– Visual “Heat Map”– Rouge detection and mitigationg g– Wireless Intrusion Detection System (WIDS)

Note: WIDS for 802.11n must support both 20 MHz and 40 MHz channelsMHz channels

For More DetailsFor 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?Questions?

Tom Jones, PE, RCDD / NTS, , /

Field Sales Engineer, D-Link

Tom Jones@dlink [email protected]

Documents

802.11 Wireless Networks - bicsi.org · 802.11 Wireless Networks ... IEEE 802 11 Gl b l M k t Gl b l M k t? ... • For Any Wireless Network Design, a Site Survey Is the