BRKEWN 3016 Niehaus Finalone

8/3/2019 BRKEWN 3016 Niehaus Finalone

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Session ID-BRKEWN-3016

Understanding RF Fundamentals and theRadio Design of Wireless Networks



© 2010 Cisco and/or its aff il iates. Al l r ights reserved. Cisco PublicPresentation_ID 2

Session Abstract

This advanced session focuses on the deep-dive understanding ofthe often overlooked Radio Frequency part of the designing anddeploying a Wireless LAN Network. It discusses 802.11 Radio,

MIMO, Access Points and antenna placements, when to use a DASsystem, antenna patterns… It covers the main environments such ascarpeted offices, campuses and conference centers, and it providesfeedback based on lessons learned from challenging deploymentssuch as outdoor/stadium/rail deployments and manufacturing areas.




Session Agenda - Objectives

What is radio how did we get here and what is frequency?

Basic 802.11 RF terminology and radio hardware identification

802.11 Antenna Basics – Single & Diversity Antennas

Interpreting antenna patterns – Cisco Richfield Facility

Diversity, Multipath, and the technical elements of 802.11n

DAS (Distributed Antenna Systems) overview – how used

Access Point Models and Features

802.11n design and deployment

Installations – above ceiling (plenum) – installations that went wrong

Antennas for Rugged Access Points – MIMO antennas for ceilings and walls




What We Won‘t Be Covering

Mesh deployments

Clean-Air (separate session for that)

Interference mitigation

Specific site survey utilities

LBS (Location Base Services)

FCC rules and regulations

WLAN management

802.11n beyond RF characteristics




What is radio?How did we get here and what is frequency?




Basic understanding of Radio…

How fast the AC current goes is its ―frequency‖

AC is very low frequency 60 Hz (Cycles Per Second)

Radio waves are measured in kHz, MHz and GHz

The lower the frequency the physically longer the radiowave – Higher frequencies have much shorter waves assuch, they take more power to move them greaterdistances. This is why 2.4 GHz goes further then 5 GHz

(given same amount of RF power)

Popular Radio Frequencies:

AM Radio 650 kHz = WSM 650 AMShortwave 3-30 MHzFM Radio 88-108 MHzWeather Radio 162.40 MHzCellular Phones 800-900 MHzWiFi 802.11a 5 GHzWiFi 802.11b/g 2.4 GHz

Battery is DCDirect Current

Typical home is ACAlternating Current

AC Frequency 60 Hzor 60 CPS – CyclesPer Second

Waves travel back and forthso fast they leave the wire

Vintage RFTransmitter


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Each Frequency or sets offrequencies (channels) have differentservices such as Shortwave, FMradio, television, etc - Most of theseare licensed services however somelike ―Wi-Fi‖ are ―unlicensed‖

Rest assured your FederalGovernment knows these

frequencies well…

DC Light

Radio Spectrum goes almost from DC to LightYou just need a radio receiver to “tune them in”



The US Radio Spectrum (3kHz-300GHz)

Uncle Sam has allocated the entire usable RF spectrum from DC to LightSource: US Department of Commerce http://www.ntia.doc.gov/osmhome/allochrt.PDF

http://www.ntia.doc.gov/osmhome/allochrt.PDF

http://www.ntia.doc.gov/osmhome/allochrt.PDF



Wi-Fi Portion of the Radio Spectrum

Wi-Fi is ―unlicensed‖ so it doesn‘t show up in

the overall spectrum allocation as a service

But it has beginnings in the ISM (industrialScientific Medical) band where it was notdesirable or profitable to license such shortrange devices.

The first frequencies availablefor Wi-Fi use was in the 900MHz and 2.4 GHz range

As Wi-Fi popularity and usageincreased the FCC allocated

additional spectrum in the 5GHz band for (unlicensedusage)

Portions of the spectrum weuse today is licensed byAmateur (Ham Radio) and

other services such as radiolocation (weather radar)

There is more bandwidth in 5GHz and mechanisms are inplace to co-exist with radiolocation (radar) services

2.4 GHz 5 GHz



A radio needs a proper antenna

Cisco antennas areidentified by colorBlue indicates 5 GHzBlack indicates 2.4 GHz

As the frequencygoes up the radiatingelement gets smaller

Antennas are custom made and havefrequency ranges and specifications

Omni-Directional antennaslike the one on the left,radiate much like

a raw light bulb wouldeverywhere in all directions

Directional antennas like this―Patch‖ antenna radiate

forward like placing tin foil

behind the light bulb or tiltingthe lamp shade

Note: Same RF energy isused but results in greaterrange as its focused at thecost of other coverage areas



Complex Modulation Schemes

Radio technology has a lot incommon with that old twisted pairphone line that started out at 300baud and then quickly increased

In order to get faster data rates,(throughput) into the radio signal,complex modulation schemes asQPSK or 64 bit QAM is used.

Generally speaking, the faster thedata rate the more powerful the signalneeds to be (at the receiver) to be

successfully decoded.

Take-away here is that 802.11n is amethod of using special modulationtechniques and *not* specific to afrequency like 2.4 or 5 GHz

802.11n can be used in either band

QAM or Quadrature Amplitude Modulation is oneof the fastest modulation types actually sendingtwo signals that are out of phase with each otherand then somehow ―putting all the pieces back

together‖ for even greater throughput.

This is one of the advantages of 802.11n

Example of 802.11n Modulation Coding Schemes



Wi-Fi Radio Spectrum

Even today many portable devices in use are limited to 2.4GHz only including newer devices but this is changing

802.11b/g is 2.4 GHz802.11a is 5 GHz802.11n (can be either band) 2.4 or 5 GHz

The 2.4 GHz spectrum has only(three non-overlapping channels1,6 and 11 (US)

There are plenty of channels inthe 5 GHz spectrum and they donot overlap

2.4 GHz and 5 GHz are differentportions of the radio band andusually require separateantennas

Most if not all 5 GHz devices

also have support for 2.4 GHz

Note: There are still many2.4 GHz only devices todayprimarily because thosechipsets are less costly to

produce



Basic 802.11 RF terminology and RadioHardware Identification



Common RF terms Attenuation – a loss in force or intensity – As radio waves travel through objects or in media such as coaxial cable attenuation

occurs.

BER – Bit Error Rate - the fraction of bits transmitted that are received incorrectly.

Channel Bonding – act of combining more than one channel for additional bandwidth

dBd – abbreviation for the gain of an antenna system relative to a dipole

dBi – abbreviation for the gain of an antenna system relative to an isotropic antenna

dBm – decibels milliwatt -- abbreviation for the power ratio in decibels (dB) of the measured power referenced to one milliwatt oftransmitted RF power.

Isotropic antenna – theoretical ―ideal‖ antenna used as a reference for expressing power in logarithmic form.

MRC – Maximal Ratio Combining a method that combines signals from multiple antennas taking into account factors such assignal to noise ratio to decode the signal with the best possible Bit Error Rate.

Multipath – refers to a reflected signal that combines with a true signal resulting in a weaker or some cases a stronger signal.

mW – milliwatt a unit of power equal to one thousandth of a watt (usually converted to dBm)

Noise Floor – The measure of the signal created from the sum of all the noise sources and unwanted signals appearing at thereceiver. This can be adjacent signals, weak signals in the background that don‘t go away, electrical noise from electromechanicaldevices etc.

Receiver Sensitivity – The minimum received power needed to successfully decode a radio signal with an acceptable BER. This isusually expressed in a negative number depending on the data rate. For example the AP-1140 Access Point requires an RFstrength of at least negative -91 dBm at 1 MB and an even higher strength higher RF power -79 dBm to decode 54 MB

Receiver Noise Figure – The internal noise present in the receiver with no antenna present (thermal noise).

SNR – Signal to Noise Ratio – The ratio of the transmitted power from the AP to the ambient (noise floor) energy present.

TxBF – Transmit beam forming the ability to transmit independent and separately encoded data signals, so-called streams , fromeach of the multiple transmit antennas



Identifying different cable types

LMR- 400 Foil & shield

LMR – 1200

½ inch solid copper cable sometimescalled ―hardline‖ or ―heliax‖ trade

names (side can be milled to be leaky)

Leaky Coaxshield cut away on one side



Antenna Cables – LMR Series

This is a chart depictingdifferent types of TimesMicrowave LMR Seriescoaxial cable.

Cisco uses Times

Microwave cable and hasstandardized on two types:Cisco Low Loss (LMR-400)and Cisco Ultra Low Loss(LMR-600).

LMR-600 is recommended

when longer cable distancesare required

Larger cables can be usedbut connectors are difficultto find and install



Antenna Cables

LMR-400 is 3/8 inch Cisco Low LossLMR-600 is ½ inch Cisco Ultra Low Loss

Trivia: LMR Stands for Land Mobile Radio



Antenna Cables - Plenum

If the cable is ORANGE in color it is usuallyPlenum Rated.

Plenum is the air-handling

space that is found abovedrop ceiling tiles or belowfloors.

Because of fireregulations this type ofcable must burn with lowsmoke

The 3 Ft white cableattached to most Ciscoantennas is plenum rated.

Our outdoor cable (black)is not Plenum

Plenum cable is moreexpensive



802.11 Antenna basics




Antenna basics

Antenna - a device which radiates and/or receives radio signals Antennas are usually designed to operate at a specific frequency

Wide-Band antennas can support additional frequencies but it‘s atrade-off and usually not with the same type of performance.

Antenna Gain is characterized using dBd or dBi

Antenna gain can be measured in decibels against a reference antennacalled a dipole and the unit of measure is dBd (d for dipole)

Antenna gain can be measured in decibels against a computer modeledantenna called an ―isotropic‖ dipole <ideal antenna> and the unit ofmeasure is dBi (i for isotropic dipole) (computer modeled ideal antenna)

WiFi antennas are typically rated in dBi.

dBi is a HIGHER value (marketing folks like higher numbers)Conventional radio (Public safety) tend to use a dBd rating.

To convert dBd to dBi simply add 2.14 so a 3 dBd = 5.14 dBi

Again… dBd is decibel dipole, dBi is decibel isotropic.




How does a Omni-directional dipole radiate?

The radio signal leaves the center wire using the ground wire(shield) as a counterpoise to radiate in a 360 degree pattern




Antenna theory (Dipole & Monopole)

Dipole

A dipole does not require a

ground plane as the bottom half

is the ground (counterpoise).

Monopole

A Monopole requires a

ground plane – (conductive

surface)

808 Ft Broadcast Monopole WSM 650

AM - Grand Ole Opry (erected in 1932)




Antenna theory (dipole & monopole)

Monopoles were added to our

antenna line primarily for aesthetics

and require a metal surface to radiate




How does a directional antenna radiate?Although you don‘t get additional RF power with a directional antenna it does

concentrate the available energy into a given direction resulting in greater

range - much like bringing a flashlight into focus.Also a receive benefit - by listening in a given direction, this can limit thereception of unwanted signals (interference) from other directions for better

performance

A dipole called the ―driven element‖ is placed in front of other elements.

This motivates the signal to go forward into a given direction for gain.(inside view of the Cisco AIR-ANT1949 13.5 dBi Yagi)




Patch Antenna a look inside

9.5 dBi Patch, AIR-ANT5195-R

Patch antennas can have multiple radiating elements thatcombine for gain. Sometimes a metal plate is used behind theantenna as a reflector for more gain




Antennas identified by color

Blue indicates 5 GHzBlack indicates 2.4 GHz




Most common 2.4 GHz antennasfor Access Points (single and diversity)

Antenna Description

AIR-ANT4941

2.2 dBi Swivel-mount Dipole; most popularmounts directly to radio, low gain, indoor

AIR-ANT5959

2 dBi Diversity Ceiling-mount Omni

AIR-ANT1729

6 dBi Wall-mount Patch

AIR-ANT1728

5.2 dBi Ceiling-mount Omni

AIR-ANT3549

9 dBi Wall-mount Patch




Most common 5 GHz antennasfor Access Points (single and diversity)

Antenna Description

AIR-ANT5135D-R3.5 dBi Omni-directional Antenna; mounts directly to radio, low gain,indoor

AIR-ANT5145V-R

4.5 dBi Omni-directional Diversity Antenna; unobtrusive, ceilingmount, low gain, indoor

AIR-ANT5160V-R6 dBi Omni-directional Antenna; ceiling or mast mount, indoor/outdoor

AIR-ANT5170P-R7 dBi Patch Diversity Antenna;directional, small profile, wall mount, indoor/outdoor

AIR-ANT5195-R9.5 dBi Patch Antenna;directional, small profile, wall mount, indoor/outdoor




Understanding and interpreting antenna patterns

A quick peek at the Cisco Richfield Facility




Understanding antenna patternsDipole (Omni-directional)

Low gain dipolesradiate everywherethink ―light bulb‖




Understanding antenna patternsMonopole (Omni-Directional) MIMO

When three monopoles are next to eachother – the radiating elements interactslightly with each other – The higher gain4 dBi also changes elevation more

compared to the lower gain 2.2 dBi Dipole




Understanding antenna patternsPatch (Directional)

5 GHz Patch Antenna




Understanding antenna patternsPatch (Higher Gain Directional)

Four element Patch Array

Single Patch Antenna




Understanding antenna patternsSector (Higher Gain Directional)

AIR-ANT2414S-R14 dBi Sector 2.4 GHz

Elevation plane has nulls due to high gain 14 dBi




Understanding antenna patternsSector (Higher Gain Directional)

AIR-ANT2414S-R14 dBi Sector 2.4 GHz

Elevation plane has nulls due to high gain 14 dBibut antenna was designed with ―Null-Fill‖

meaning we scaled back the overall antennagain so as to have less nulls or low signal spotson the ground.




The Richfield Ohio (Aironet) facilityA quick peek where antennas are designed...




The Richfield Ohio (Aironet) facility designsantennas and qualifies 3rd party antennas

Satimo software compatible withStargate-64 System. Basicmeasurement tool is 8753ESNetwork Analyzer.

Cisco Anechoic chamber using an 18-inchabsorber all the way around 1-6 GHzAnechoic means ―without echo‖




FCC regulatory compliance testing is alsodone at the Richfield Ohio facility.




Yes we have just a few Access Points…




RF Screen rooms everywhereCopper shielding (Faraday Cage)




Cables are typically fiber and exitthrough well shielded holes

Doors have copper fingers andlatch tight forming an RF seal

RF Screen roomsCopper shielding on top metal on bottom




RF Screen roomsCopper shielding (Faraday Cage)




Cisco Richfield Facility




Understanding multipath and diversityand the technical elements of 802.11n




As radio signalsbounce off metalobjects they oftencombine at thereceiver

This often results ineither an improvement―constructive‖ or a

―destructive‖ type of

interference

Understanding MultipathMultipath can change signal strength

Note: Bluetooth type radios that ―hop‖ across the entire band can reduce multipath

interference by constantly changing the angles of multipath as the radio waveincreases and decreases in size (as the frequency constantly changes) howeverthroughput using these methods are very limited but multipath is less of a problem




Understanding MultipathMultipath reflections can cause distortion

As the radio waves bounce they can arriveat slightly different times and angles causingsignal distortion and potential signalstrength fading

Different modulation schemes fair better –802.11a/g/n uses a type of modulationbased on symbols and is an improvementover the older modulation types used with802.11b clients

802.11n with more receivers canuse destructive interference(multipath) as a benefit.

Tip: It is still best to reducemultipath conditions wheneverpossible – Keep antennas awayfrom metal objects




Antenna placement considerations

Never mount antennas nearmetal objects as it causesincreased multipath and

directionality

AP antennas need placements that are awayfrom reflective surfaces for best performance

Avoid metal support beams, lighting andother obstructions.

When possible or practical to do so, alwaysmount the Access Point (or remote

antennas) as close to the actual users asyou reasonably can

Avoid the temptation to hide the AccessPoint in crawl spaces or areas thatcompromise the ability to radiate well

Think of the Access Point as you would alight or sound source, would you really put a

light there or a speaker there?




Non-802.11n diversity Access Points use two antennas sampling eachantenna choosing the one with the least multi-path distortion

Cisco 802.11a/b/g Access Points start off favoring the right (primary

antenna port) then if multi-path or packet retries occur it will sample theleft port and switch to that antenna port if the signal is better.

Note: Diversity Antennas should always cover the same cell area

Understanding Diversity (SISO)802.11a/b/g diversity has just one radio




Receiver benefit as each antenna has a radio section

MRC is done at Baseband using DSP techniques

Multiple antennas and multiple RF sections are used in parallel

The multiple copies of the received signal are corrected and combined atBaseband for maximum SNR (Signal to Noise) benefit

This is a significant benefit over traditional 802.11a/b/g diversity where only oneradio is used

Understanding Diversity (MIMO)MRC Maximal Ratio Combining (three radios)



© 2010 Cisco and/or its aff il iates. Al l r ights reserved. Cisco PublicPresentation_ID 51Presentation_ID © 2006 Cisco Systems, Inc. All r ights reserved. Cisco Confidential 51

Understanding 802.11 MIMO terminology

MIMO (Multiple-Input-Multiple-Output)

Some RF components of 802.11n include:

MRC – Maximal Ratio Combining a method that combines signals from multiple antennas taking into accountfactors such as signal to noise ratio to decode the signal with the best possible Bit Error Rate.

TxBF – Transmit beam forming – The ability to transmit independent and separately encoded data signals, so-called ―streams‖ from each of the multiple transmit antennas.

Channel Bonding – Use of more than one frequency or channel for more bandwidth.

Spatial Multiplexing – A technique for boosting wireless bandwidth and range by taking advantage of multiplexingwhich is the ability within the radio chipset to send out information over two or more transmitters known as ―spatial

streams‖.

Note: Cisco 802.11n Access Points utilize twotransmitters and three receivers per radio module.

MIMO is pronounced ―My Moe‖ not to be confused with this Moe.




MIMO 40MhzChannels

PacketAggregation

BackwardCompatibility

Technical Elements of 802.11n

MIMO 40Mhz ChannelsPacketAggregation





Aspects of 802.11n

Beam Forming Spatial MultiplexingMaximal Ratio Combining

MIMO (Multiple Input, Multiple Output)



Performed byTransmitter(Talk Better)

Ensures SignalReceived inPhase

IncreasesReceiveSensitivity

Works withnon-MIMO andMIMO Clients

Without Beam FormingTransmissions Arrive out ofPhase and signal is weaker

With Beam FormingTransmissions Arrive in Phase,

Increasing Signal Strength




Aspects of 802.11n



40Mhz ChannelsPacketAggregation


Performed byReceiver(Hear Better)

CombinesMultiple ReceivedSignals

IncreasesReceiveSensitivity

Works withnon-MIMO andMIMO Clients

Performance

Multiple Signals Sent;One Signal Chosen

Without MRC

Multiple Signals Sent and Combinedat the Receiver Increasing Fidelity

With MRC

MIMO AP




Aspects of 802.11n





Transmitter andReceiverParticipate

ConcurrentTransmission onSame Channel

IncreasesBandwidth

Requires MIMOClient

Performance

stream 1

stream 2

Information Is Split and Transmitted on Multiple Streams

MIMO AP




20-MHz

20-MHz

40-MHzGained Space

MIMO (Multiple Input, Multiple Output)40Mhz Channels

Aspects of 802.11n



Moving from 2 to 4 Lanes

40-MHz = 2 aggregated 20-MHz channels—takes advantage of thereserved channel space through bonding to gain more than double thedata rate of two 20-MHz channels




40Mhz Channels

Aspects of 802.11n

Packet Aggregation


MIMOBackwardCompatibility

Carpooling Is More Efficient Than Driving Alone

Without Packet Aggregation

DataUnit

Packet

802.11nOverhead

DataUnit

Packet

802.11nOverhead

DataUnit

Packet

802.11nOverhead

With Packet Aggregation

Data Unit

Packet802.11nOverhead

PacketPacket




Packet AggregationBackward Compatibility

Aspects of 802.11nPacketAggregation


MIMO 40Mhz Channels

2.4GHz 5GHz

802.11ABG Clients Interoperate with 11n ANDExperience Performance Improvements

11n Operatesin BothFrequencies




1 2 6 113 4 5 7 8 9 12 13 1410

2.402 GHz 2.483 GHz

40MHz 802.11n channel

Channel Bonding:Wider channels means more bandwidth per AP

Understanding MCS rates and Channel Bonding

20 MHz channel

MCS rates 0-15 applyRegardless of channelBonding.

MCS 0-7 is one Spatial Stream

When you bond a channelYou have a control channel and adata (extension) Channel

Legacy ABG clients use controlchannel for communication




2.4 GHz, 40 MHz Bandwidths

Tip: Channel bonding in 2.4 GHz should be avoided in enterprise deploymentsTip: Use 5 GHz as there are no overlapping channels to worry about




Example UNII-3 Channel Bonding

In 40-MHz you define the control channel this is the channel thatis used for communication by Legacy .11a clients.

The Extension channel is the bonded channel that HighThroughput ―HT‖ 802.11n clients use in addition to the controlchannel for higher throughput as they send data on BOTH

channels




Channel Bonding - Subcarriers

When using the 40-MHz bonded channel, 802.11n takes advantage of the fact that each 20-MHz channel

has a small amount of the channel that is reserved at the top and bottom, to reduce interference in thoseadjacent channels.

When using 40-MHz channels, the top of the lower channel and the bottom of the upper channel don'thave to be reserved to avoid interference. These small parts of the channel can now be used to carryinformation. By using the two 20-MHz channels more efficiently in this way, 802.11n achieves slightly more

than doubling the data rate when moving from 20-MHz to 40-MHz channels

802.11n uses both 20-MHz and 40-MHzchannels.

The 40-MHz channelsin 802.11n are two

adjacent 20-MHzchannels, bondedtogether.




Understanding Guard Interval

The guard intervalthat is part of eachOFDM symbol is aperiod of time that isused to minimizeinter-symbol

interference.

This type ofinterference iscaused in multipathenvironments whenthe beginning of anew symbol arrivesat the receiver beforethe end of the lastsymbol is done.

Default mode for 802.11n is 800 nanosecondsIf you set a shorter interval it will go back to long

in the event retries occur




54 48 36 24 Mbps

54 Mbps MRC

TxBF

Spatial Multiplexing

802.11a/g AP(non-MIMO)

802.11n AP(MIMO)

802.11a/g client(non-MIMO)

802.11a/g client(non-MIMO)

300 Mbps802.11n AP

(MIMO)

802.11n client(MIMO)

MRC

TxBF


MRC

TxBF


802.11n OperationThroughput improves when all things come together

Channel Bonding




MCS index of 802.11n rates




Understanding DAS Antenna SystemsOverview – How used

Antenna Technologies ―DAS‖




Antenna Technologies ―DAS‖Traditional DAS deployments over coaxial cable

DAS – Distributed Antenna System Mostly seen in healthcare, higher education & hospitality

Major benefits of DAS include:

Carry multiple wireless signals simultaneously (cellular, paging, etc)

Consolidates work above ceiling – fewer cables

Aggregates majority of active components in closet for easy replacement

Disadvantages

Usually one antenna per AP – lack of MIMO and diversity support

Cisco TAC will not support RF signal when radio is separated from theantenna on non-Cisco equipment

Compromises the benefits of CUWN‘s advanced features including RRM,Location, VoFi, etc.

Reduced technology migration paths - 802.11n can be more difficult tosupport

Large solid copper cable once installed, is difficult to move if changes arelater required (remodeling etc).




How does DAS work?

DAS works by placing multiple radio services on a common cableor antenna system using selective filters and/or a low gainmultiband antenna.

Two methods are typically used ―Leaky coax‖ and ―discretewideband antennas‖ or sometimes a combination of both.

Tip: Avoid daisy-chaining antennas as this breaks key features

like location/voice based services – use only discrete widebandantennas (one antenna per AP) with this type of DAS

Leaky ―radiating‖ coaxial cable

Bad for location based applicationsWide-Band antenna




Leaky coax DAS

Leaky coaxial systems are sometimes used in mining applications and assembly lines(think above assembly work benches)

For leaky coax to be effective, it needs to be installed in very close proximity to the actual WLANusers (distances are short typically 5-20 Ft) and will not work reliably at higher 5 GHz

frequencies. Limited to single channel - high potential for co-interference issues

Note: Leaky coax should be used for only the most basic Wi-Fi scenarios, i.e. light connectivityfor low bandwidth apps. Not recommended for features such as voice or location

Cable has shielding removedon one side – center radiates




Traditional coaxial DAS solutions

Depending on the type of ―wide band antenna‖ DAS system used, signalsleave the Access Point‘s antenna port and go through RF filters

(passive) and/or bi-directional amplifiers (active) circuitry

While better then a leaky coaxial system, it is not a simple installation andrequires professional installers with experience cutting and terminatingthe expensive (solid copper shielded) cable. Connector termination can

be a point of failure and cable moves can be expensive

Note: Unused antenna ports should be terminated to avoid interference toAccess Points that are co-located

RP-TNCTerminator

New approach




New approachIn-building cellular – CAT 5e/6/6a

Cisco has a Solutions Plus Resell partnership with Mobile Access

Whereas Cisco resells the MA branded and supported product

Mobile Access active indoor cellular over same UTP

cable that can be shared with Cisco Access Points

New approach




New approachIn-building cellular – CAT 5e/6/6aMobile Access Pod using one UTP cable from the cellular controller

can filter the cellular signals from the cable and pass GigE PoEto the Cisco Access Point

• Eliminates the need for expensive solid copper cabling and the complexities of same• Enables quicker and cost effective deployment with common UTP cabling• Allows MA solution & Wi-Fi to co-exist on one single UTP cable• No modifications or wide band antennas, no terminators are required on the AP

Note: Cisco Access Points with integrated antennas can also be used with this solution.

Cellular and Wi-Fi sharing CAT-5e/6/6a




Cellular and Wi-Fi sharing CAT-5e/6/6a

WLAN APSwitch

New / Existing Cat-5/6 Ethernet GigE

POE Alt A

WLAN “802.11n”

Ethernet-LANTraffic Passes

Over

0 to ~100 MHz

MobileAccessVEShifts Carrier to

IntermediateFrequencies

FrequenciesStarting at

140 MHz andAbove

Shared StructuredCabling System isPassive to WLAN

and Cellular

Cellular “Cell, PCS”

BDA, BTS,Pico, Femto

AccessPodCellular

Controller

2 Cellular Bands or 1 MIMO Service

POE Alt B

Co-existence of




Wi-Fi and Cellular Antenna

Wi-Fi overTraditional DAS

Shared Coax cablingAPs in closet

No Cisco RF Support

Likely no MIMO, MRCor ClientLink, RRM,Poor roaming, Location

Overlay

No Wi-Fi limitations

Expensive cabling

Duplicate cabling

Cellular over CAT5

No Wi-Fi limitationsCheap UTP cables

RF signals limited by

UTP cabling two forCAT5 more with CAT6a




Access Point Models and Features

Introduction of new Access Points




C a r p e t e d

R u g g

e d i z e d

11abg 11n + CleanAir11n

1130

12401260

3500e

3500i1140

Introduction of new Access Points

1250

Ai t I d A P i t C i




AP 1130 AP 1140 AP 3500i AP 1240 AP 1250 1260 3500e

Integrated CleanAir No No Yes No No No Yes

Data Uplink (Mbps) 10/100 10/100/1000 10/100/1000 10/100 10/100/1000 10/100/1000 10/100/1000

Power Requirement 802.3af 802.3af 802.3af 802.3afE-PoE

802.3af*802.3af 802.3af

Installation Carpeted Carpeted Carpeted Rugged Rugged Rugged Rugged

Temp Range 0 to +40°C 0 to +40°C 0 to +40°C -20 to +55°C -20 to +55°C -20 to +55°C -20 to +55°C

Antennas Internal Internal Internal External External External External

Wi-Fi standards a/b/g a/b/g/n a/b/g/n a/b/g a/b/g/n a/b/g/n a/b/g/n

DRAM 32 MB 128 MB 128 MB 32 MB 64 MB 128 MB 128 MB

Flash 16 MB 32 MB 32 MB 16 MB 32 MB 32 MB 32 MB

Aironet Indoor Access Point Comparison

•802.3af fully powers single radio AP1250 or provides 1x3 performance on a dual radio 1250

Integrated antenna? – External antenna?




g

Integrated antenna versions

are designed for mountingon a ceiling (carpeted areas)where aesthetics is aprimary concern

Use for industrial applications

where external or directionalantennas are desired and orapplications requiring highertemperature ranges

Carpeted areas Rugged areas

Wh i d




When to use integrated antennas

When there is no requirement for directionalantennas and the unit will be ceilingmounted

Areas such as enterprise carpeted officeenvironments where aesthetics areimportant

When the temperature range will notexceed 0 to +40C

Wh l




When to use external antennas

Reasons to consider deploying a rugged AP

When directional ―focused‖ coverage is desiredor greater range is needed

The environment requires a more industrialstrength AP with a higher temperature rating of-20 to +55 C (carpeted is 0 to +40 C)

The device is going to be placed in a NEMA

enclosure and the antennas need to beextended

You have a desire to extend coverage in twodifferent areas with each radio servicing anindependent area - for example 2.4 GHz in theparking lot and 5 GHz indoors

Requirement for outdoor or greater rangeBridging application (aIOS version)

Requirement for WGB or mobility applicationwhere the device is in the vehicle but antennasneed to be mounted external

Rugged AP in ceiling enclosure

Wh t AP 1240 d AP 1250




When to use AP-1240 and AP-1250

Reasons to consider the AP-1240 or AP-1250

The AP-1240 and AP-1250 support highergain antennas - a benefit only if a high gainantenna already exists or is required

Higher gain (up to 10 dBi) can improveWGB and outdoor Bridging distances

Recommend the AP-1240 if theinfrastructure is older 10/100 ports andthere is no interest in upgrading to 11n

AP-1240 will work with older Cisco PoEswitches (Cisco proprietary power)

AP-1240 draws less power so better forsolar applications

AP-1240 supports Cisco Fiber injectors

Tip: Higher than 10 dBi antenna gains aresupported with the 1300 Series Bridge/AP




802.11n Design and Deployment




Phases of 802.11n deployment

Design Considerations

•Which AP to choose

•1:1 Replacement Strategy for Capacity

•5 GHz Strategy

•11n Clients

Planning

•WCS Planning Tool

•Infrastructure Considerations

Deployment

•Site Survey

Operation

•Configuration (40 MHz RRM, Data Rates, Security, etc.)

•Tracking and augmenting controller capacity

Whi h 802 11 A P i t i i ht?




Which 802.11n Access Point is right?

AP-3500i and AP-3500e have the verylatest Cisco features such as Clean AirCisco‘s spectrum intelligence

AP-1140 and AP-1260 are of similar

design less Cisco Clean Air features andcan also run autonomous code (aIOS)for stand alone or Workgroup Bridgeapplications.

Note: 3500 Series does not support theolder aIOS autonomous mode

All the Access Points were designed tohave similar coverage for ease ofdeployment




AP1140 AP1250

AP3500i AP3500e

Coverage Comparison – 5GHz

1130 Access Point




1130 Access PointPlacement

1130 Access Point Placement1 per 5,000 sq feet for data only

1 per 3,000 sq feet for voice, location

SeveralSupported Apps

Email

Web

Radio Resource Management

Adaptive channel / power coverage

Operational simplicity

1140, 3500i Access Point




1140, 3500i Access PointPlacement

Improved coverage at

higher data rates

1 for 1 replacementAP1140, 3500i reuses existingAP1130 T-Rail Clip

More Applications Supportedat Any Given Location

Email

WebVoice

Video

Backup

ERP

ABG

ABG

ABG

ABG

Access Points (Internal Antenna Models)




Access Points (Internal Antenna Models)Designed Primarily for ceiling (carpeted) Installations

Access Point has six integrated802.11n MIMO antennas

4 dBi @ 2.4 GHz3 dBi @ 5 GHz

Note: Metal chassis andinverted ―F‖ antenna

elements were designed tobenefit ceiling installations asthe signal propagatesdownward in a 360 degreepattern for best performance

Antenna element

Antenna Patterns




Antenna PatternsAzimuth and Elevation Patterns for 2.4 GHz & 5 GHz

2.4 GHzAzimuth

5 GHzAzimuth

5 GHz

Elevation

2.4 GHz

Elevation

AP Placement – Wall Mounting




AP Placement Wall Mounting

Wall mounting is acceptablefor small deployments suchas hotspots, kiosks, etc butradiation is better on ceiling

Best for enterprise deployments ascoverage is more uniformespecially for advanced featuressuch as voice and location

AP-1140 and AP-3500i AP-1260 and AP-3500e

What about mounting options?




What about mounting options?Different mounting options for ceiling APs

Cisco has options to mount tomost ceiling rails and directly intothe tile for a more elegant look

Locking enclosures and differentcolor plastic ―skins‖ available from

third party sources such aswww.oberonwireless.comwww.terrawave.com

AP Pl t E l t P bl A

http://www.oberonwireless.com/

http://www.terrawave.com/

http://www.terrawave.com/

http://www.oberonwireless.com/




AP Placement—Evaluate Problem Areas

Object in Signal Path

Plasterboard wall

Glass wall with metal frame

Cinder block wall

Office window

Metal door

Metal door in brick wall

Phone and Head position

3 dB

6 dB

4 dB

3 dB

6 dB

12 dB

6 dB

SignalAttenuation

Clips adapt Rail to ―T‖ bracket.




p pAttaching to fine line ceiling rails

If the ceilingrail is not wideenough or toorecessed forthe ―T‖ rail this

can beresolved usingthe optionalclips

Part number for ceiling clips is AIR-ACC-CLIP-20=This item is packaged in 20 pieces for 10 Access Points

Effective Frequency Use—5GHz and 2.4GHz




q yCreate a 5GHz Strategy

5GHz Recommended for 802.11n• More available spectrum—greater number of channels

• Reduced interference (no Bluetooth, Microwave Ovens, etc.)

• Maximum throughput in a 40MHz channel

• Many 11n devices only support 40MHz in 5GHz

2.4GHz still benefits from MIMO and packet aggregation

1

6 11

2

1 3 5 7 9 11

4 6 8 10

5GHz 40MHz Channels2.4GHz 20MHz Channels

11n




Client Adapters

Make sure adapter is 11n Draft 2.0 or better certified by WiFiAlliance - http://www.wi-fi.org

802.11n adapters have a major influence on performancelevels that can be achieved

Built-in 11n adapters out perform add-on• USB and PCMCIA 11n adapters have less than optimal antennaplacement as those form factors have less then ideal antenna spacing

Not realistic to upgrade most older laptops with internal 11nadapters

• Need three antennas connectors

11n Client Adapter

http://www.wi-fi.org/








pRecommendations

Update 802.11n client drivers to the latest revision

Cisco-Intel relationship means that the Intel 11n adapterwith Cisco‘s APs have had the most test time

WCS Planner




1140 and 11n Support

Set AP type

Select ‗Enable 11n support‘

Select protocol‗802.11a/n, b/g/n‘

Select optimize for HT

Select Voice & location if desired

Calculate/Apply/Add APs to Map

WCS Planner




Data Rate Heat Map

Add APs to map

Set Heat Map type to Data Rates

Set Cutoff to desired minimum data rates

WCS Planner




Proposal

Generate proposal

Use proposal for budgetary estimates Use proposal with survey to create final install

AP count and placement design

Recommend survey to validate and calibrate proposal results

Third Party Survey Tools




There are many and I believe they are all good

Airmagnet

EDX

Ekahau

Helium Networks

Wireless Valley

… and many others

Tip: Survey and use Cisco antennas

If you contract this out, some companies use theirown antennas and then lock you into them saying―that‘s what we surveyed with‖… if in doubt use

Cisco Advanced Services as they also performsite surveys

Site SurveyS S




Site Survey Recommendations

Use ―Active Survey‖ tools

• Example - AirMagnet 6.0 uses Iperf tosend traffic when surveying to measureactual data link speeds

Survey for lowest commonclient

• Once for 11a/g clients

• Once for 11n clients (optional)

Survey at intended AP power levels

11n Deployment ExpectationsD S i




Data Services

Range• 10-15% increase in maximum range versus a non-N AP

• Recommended 1:1 replacement of an 802.11a/g deployment

Coverage• 10-20% increase in 802.11a/g high data rate coverage

• More uniform coverage and consistent coverage (MIMO)

Capacity

• Largest gain for 802.11n capable clients

• Maximum data rates of 144Mbps in 2.4GHz

• Maximum data rates of 300Mbps in 5GHz

Improved 802.11g Coverage1130 1140 11G A ti S




1130 11G Survey

48 Mbps Coverage

86 Feet

1140 11G Survey

48 Mbps Coverage

102 Feet

1130 vs. 1140 —11G Active Survey

18% Increase in 802.11g Coverage

Note the more uniform coverage of high (green) data rates

5GHz - Maximum Range




5GHz Maximum Range

AP1130 – 5GHz AP1140 – 5GHz

802.11n DeploymentDesigning Around 5GHz 40MHz Channels




Designing Around 5GHz 40MHz Channels

One APData Rate vs. RSSI

Full DeploymentContiguous 5GHz Coverage

5 GHz Dynamic Frequency Selection




5 GHz Dynamic Frequency Selection

When Radar IsPresent

APs ShiftChannels—

Results in LowerAvailable Channels

and Loss of UNI 2and UNI 2e Bands Radar

Available40MHzChannels

No DFSSupport

DFSSupport

4 11

5 GHz Frequency

UNI 1 UNI 2 UNI 2 Ext. UNI 3UNI 2 UNI 2 Ext.

DFS and Available Bandwidth




DFS and Available Bandwidth

Full DFS support is required forcomplete use of channels in 5GHz

Limited DFS support directlyimpacts available bandwidth

Limited bandwidth restrictsapplication support andnegates investment in 11n

Available Channels per Region Theoretical Cisco Meru/Aruba

United States

11n 5GHz

20MHz

24 21 8

11n 5GHz40MHz

11 9 4

Europe

11n 5GHz20MHz

19 19 4

11n 5GHz40MHz

9 9 2

Available Bandwidth in 5GHz for 11n

0

150

300

450

600

750

900

1050

1200

1350

Meru/Aruba Meru/Aruba Cisco Cisco

* 40 MHz Channels in 5GHz

600Mbps

300Mbps

1350Mbps 1350Mbps

US Europe

USEurope

Tuning RRM 5GHz Channel SelectionUNII 2 Extended Channel Considerations




UNII-2 Extended Channel Considerations

Wireless ->802.11a/n -> DCA

Uncheck channels 100-140

(UNII2-Extended)

Some older clientscannot utilize UNII-2Extended Channels

The 5GHz radio couldbe ‗invisible‘ to the client

If your clients do notsupport these channelsthey can be disabledsee below

Utilizing 11n Wide Channels20MHz vs 40MHz Considerations




20MHz vs. 40MHz Considerations

The 40MHz mode of 802.11n provides the highest throughput withdata rates of 300Mbps

• Should not be utilized in the 2.4GHz band

• Not enough channels for 40 MHz mode

The 5GHz band has enough spectrum to make 40MHz feasible

• Use 20MHz for 802.11a voice deployments

• Use 40MHz for maximum data throughput with 802.11n clients

Use RRM for 40MHz

Mixed ModePerformance




Performance

11n

300 Mb54 Mb

WLAN Controller

11n

11g

Mixed mode experiences slightperformance impact due to ABGclients

11n clients still transmit at fullperformance

PHY and MAC for 11n provides co-existence and protection for ABGclients

Move 11n clients to 5GHz, keep

legacy clients at 2.4GHz

Improving Mixed Mode PerformanceDisabling Unnecessary Data Rates




Disabling Unnecessary Data Rates

Benefit: Beacons and Broadcast traffic utilizeless ―airtime‖

For 802.11b/g deploymentsDisable: 1, 2, 5.5, 6 and 9Mbps

For 802.11g-only deployments

Disable: 1, 2, 5.5, 6, 9 and 11Mbps

For 802.11a deploymentsDisable: 6 and 9 Mbps

Higher rates can also be disabled (ex. 12,

18Mbps) – dependant on deployment

Tuned 802.11b/g Data Rates:




Installations – Above Ceiling (Plenum)When they must be invisible

AP Placement in Plenum Areas




When placing the Access Point above theceiling tiles (Plenum area) Ciscorecommends using rugged Access Pointswith antennas mounted below the Plenumarea whenever possible

Cisco antenna have cables that are plenumrated so the antenna can be placed below

the Plenum with cable extending into theplenum

If there is a hard requirement to mountcarpeted or rugged Access Points usingdipoles above the ceiling – This can bedone however uniform RF coveragebecomes more challenging especially if

there are metal obstructions in the ceiling

Tip: Try to use rugged Access Points andlocate the antennas below the ceilingwhenever possible

Installation above the ceiling tilesA ti l il b th til b d




An optional rail above the tiles may be used

Note: The AP should be as close to the tile as practical

AP bracket supports this optional T-bar box hanger item 2(not supplied) Such as the Erico Caddy 512 or B-Line BA12.

Installation above the ceiling tilesM t AP l t th til d f bj t




Mount AP close to the tiles and away from objects

Installing Access Pointsabove the ceiling tilesshould be done only whenmounting below the ceilingis not an option.

Such mounting methodscan be problematic foradvanced RF featuressuch as voice and locationas they depend on uniformcoverage

Try to find open ceiling areas away frommetal obstructions (use common sense)

Tip: Mount antennas eitherbelow ceiling tile or the APas close to the inside of thetile as possible

Plenum installs that went wrongYes it happens and when it does its bad




Yes it happens and when it does its bad…

When a dipole is mountedagainst a metal object youlose all Omni-directionalproperties.

It is now essentially adirectional patch sufferingfrom acute multipathdistortion problems.

Add to that the metal pipesand it is a wonder it worksat all.

Dipole antennas up against a metal box create apatch like antenna - that plus metal pipes createunwanted Multipath Destructive Interference

Tip: Try to get Access Pointsclose to the actual users – Thisantenna is radiating forwardhigh in the ceiling where thereare no users - try to avoid thesetypes of installs

Plenum installs that went wrongHuh?? You mean it gets worse?




Huh?? You mean it gets worse?

Antennas cannot radiate well with all this mess – someone went to a lot of―trouble‖ to mount this -- just to encounter even more connectivity ―trouble‖.

Installations that went wrong




Ceiling mount AP up against pipe not goodAntennas are obstructed

Metal duct blocking antenna causingMultipath interference





Mount the box ―lid down‖ withthe antennas pointingdownward – Tip: Antennas donot work well against metal

Patch antenna - Shooting across a metalfence – Put it on a cross arm away from fenceor find a better location





Sure glad this particular model runs abit on the warm side --- ―Chirp Chirp‖

I guess most dry wall guysare not radio engineers –

Exactly how did this happen?

Minimize the Impact of Multipath




p p

Temptation is to mount on beams orceiling rails

This reflects transmitted as well asreceived packets

Dramatic reduction in SNR due to

high-strength, multipath signals

Minimize Reflections When Choosing Locations




Antennas for Rugged Access Points802.11n options for ceilings and walls

Guide to Antenna part numbers




p

MIMO Ceiling Antenna 2.4 GHzAIR-ANT2430V-R (3 dBi ceiling mount Omni)




( g )

Antenna has threemonopole elements

MIMO Ceiling Antenna 5 GHzAIR-ANT5140V-R (4 dBi ceiling mount Omni)




( g )

Antenna has threemonopole elements

AIR-ANT2451NV-R




2.4 GHz (2.5 dBi) & 5 GHz (3.5 dBi) dual band ceiling omni

Six leads - 5 GHz antennas have blue

markings (shrink wrap)

AIR-ANT2460NP-R




2.4 GHz 6 dBi Three Element Patch

AIR-ANT5160NP-R




5 GHz 6 dBi Three Element Patch

AIR-ANT2450NV-R= & AIR-ANT5140NR-RMIMO “Multi-mount” Omni 2.4 GHz and 5 GHz




MIMO Multi mount Omni 2.4 GHz and 5 GHz

New 3 in 1 Antenna for 2.4 GHz and 5 GHz.

Gain should be 4 dBi for each antenna – but

may be higher depending on how much

gain we can achieve.

New Cisco Antenna part numbers




Outdoor weatherproofing




Outdoor weatherproofingCoax-Seal can be used with

or without electrical tape.

Taping first with a qualityelectrical tape like Scotch 33+vinyl allows the connection tobe taken apart easier.

Many people tape then useCoax-Seal then tape againthis allows easy removal witha razor blade.

Note: Always tape from thebottom up so water runs overthe folds in the tape. Avoidusing RTV or other causticmaterial.www.coaxseal.com




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