In Building 101, Jack Daniel IWCE 2009

IWCE 2009
AGENDA
In-Building 101
A Primer for RF
Distribution Technology
Presented by
Jack Daniel, Jack Daniel Co.
Reasons Why In-Building Coverage is
Important:
Every Reason You Have an
Outdoor Radio System
applies equally to having
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Overview of Radio Propagation.
Common Reasons for “Dead Spots”.
Different Ways to Reduce Dead Spots.
Types of Signal Boosters
Distributed Antenna System designs
FCC Signal Booster Rules
Signal Booster Codes
New Signal Booster Developments.
Questions and Comments.
Every time a
First Responder
enters a
High Rise building,
basement, subway or
large mall chances are
Public safety
radio communications
may not be reliable.
In-Building communications as well.
In-building Industry Nomenclature
Typical In-Building Coverage Problem
In-building Industry Nomenclature
- The FCC Rules identify special in-building amplifiers
as “Signal Boosters”. Within the wireless industry,
a signal booster may also be called a “Bi-Directional
Amplifier or “BDA”. They are the same device.
DOWNLINK: The RF direction of flow FROM a base
station TO a radio inside the structure.
- Some rf distribution designs may use radiating
coaxial cables which are also called ‘leaky coax’.
DONOR SITE: A distant base or repeater location.
- A system that includes multiple inside antennas
is called Distributed Antenna System or “DAS”.
© Jack Daniel Co, 2008 800-NON-TOLL
UPLINK:The RF direction of flow TO a base station
FROM a radio inside the structure.
DONOR ANTENNA: The antenna (typically on the
roof) that connects the path to the Donor site.
SERVICE ANTENNA: Antennas used inside the
structure, or "in-door" antennas.
page 1
IWCE 2009
DONOR
SITE
Typical In-Building Coverage Problem
In-building Industry Nomenclature
COMPOSITE POWER: The total power of all
channels passed in a Class B signal booster.
Note that a Class B signal booster with a 10 watt
rated output amplifier will NOT provide 10 watts on
all the channels.
For example, 10 equal level channels input to a
10 watt broadband power amplifier will had 1 watt
out put power per channel.
In-building Industry Nomenclature
Decibels are mathematical values of RF power levels
or ratios. In RF system designs, watts and microvolts
are converted to dBm’s, a real amount relative to
1 milliwatt power level.
Once all values are converted to dBm,
calculations are simply add and subtract.
Gains and losses are stated as RATIOS in dB’s
(not dBm)
dB’s are logarithmic so, for example;
2x = 3 dB, 5x = 7 dB, 10x = 10 dB changes
In-building Industry Nomenclature
Distributed Antenna System “DAS”
The most commonly used term used to identify an inbuilding system consisting of multiple antennas
placed inside the structure.
Cellular system engineers often interpret DAS as
only a term that only applies to cellular systems.
“DAS” is used as verbal shorthand for almost all inbuilding RF distribution systems.
In-building Distribution Types
The cellular industry has established term that are
now being adopted by other in-building system
designers :
PASSIVE: The portions that have no active devices,
such as coax directly connected to a station or BDA
with no further amplifiers.
Radio Signal
Propagation
ACTIVE: A DAS system that includes rf amplification
or RF conversion, such as in-line boosters or RF over
fiber).
HYBRID: A system that has both Passive and Active
portions. This is the most common after Passive.
© Jack Daniel Co, 2008 800-NON-TOLL
page 2
IWCE 2009
Radio Signal Propagation
• Radio signals travel from point to point in a
fashion similar to light.
• Radio signals can ‘penetrate’ some distance
through many types of non-metallic
obstacles like glass, wood, bricks, trees, fog,
etc.
• As radio signals pass through ANY obstacle,
even air, they loose strength.
URBAN CLUTTER
Radio Signal Propagation
• When radio signals encounter metallic and
masonry obstacles the signal is attenuated
greatly and portions may be reflected away
from the desired path.
• Weakened radio signals reduce the range of
the radio system, both transmit and receive.
• Portables may receive in a structure but not
send because of their lower transmit power.
Typical Areas of Poor RF Coverage
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Buildings, especially basement levels.
Subways, mines.
Parking Garages.
Naturally Shadowed Areas :
(Canyons, behind hills, river bottoms, etc.)
In Public Safety
A dead Spot can be
a DEAD Spot!
© Jack Daniel Co, 2008 800-NON-TOLL
page 3
IWCE 2009
Typical Areas of Poor RF Coverage
Extending Radio System Range
NATURAL
• Mines.
(1st signalOBSTACLES
booster use: 1978)
• Inside Buildings, especially lower floors.
(City Halls, Hospitals, Colleges, Casinos)
• Convention Centers, Aquariums, Museums
• Basements, Tunnels, Underground Facilities.
(EOCs, Utility services, VIP access, etc.)
• Malls, Auditoriums, Stadiums, Theaters.
• Stairwells and elevators.
SIGNAL BOOSTERS ARE
NOT
INTENDED TO BE USED TO INCREASE
THE OUTDOOR RANGE OF A
RADIO SYSTEM,
BOTH BY DESIGN AND FCC RULES!
In-Building
Coverage Solutions
THE COVERAGE PROBLEM
Blocked Signal Solution #1
Increase Transmit Power
GOOD
COVERAGE
POOR
COVERAGE
© Jack Daniel Co, 2008 800-NON-TOLL
• Portable Transmit power wont be increased,
so only “Talk-Out” is improved.
• Will require FCC license modification.
• May have FCC ERP limitations.
• Will have to increase power by many
multiples to have any notable improvement.
• Provides NO improvement if signal is blocked
by a major obstacle. (Mtns, Basements, etc.)
page 4
IWCE 2009
Blocked Signal Solution #2
Build More Base Stations
• VERY expensive solution, especially when
problem is in many widely scattered areas.
• Multiple bases or repeaters require additional
equipment to ‘network’ them to work as an
integrated, manageable system.
• Control circuits (microwave, telco lines) are
required to link the sites together.
• Additional control console positions may be
required.
Blocked Signal Solution #3
Use Satellite Receivers
• Satellite receiver systems only address the
“talk-back” side of the radio conversation.
• Additional equipment (voting panels, console
positions, etc.) will be required also.
• Links (microwave, telco lines, etc.) are
required to all satellite receiver sites, causing
higher monthly operating costs in most cases.
Blocked Signal Solution #4
Add Small “Fill-In” Repeaters
inside problem areas.
• May requires additional radio channels for
“cross-band” communications.
• Only one channel may be available.
• Will require additional FCC licenses & fees.
• Users have to know when to switch channels
when moving from inside to outside and vice
versa. A highly error prone procedure.
• A ‘jammed’ fill-in repeater can block the
whole radio system.
© Jack Daniel Co, 2008 800-NON-TOLL
Blocked Signal Solution #5
Install “Passive” Antennas
• Low cost, low maintenance choice but only
works well in less than 10% of cases.
• Requires VERY strong signals outside of the
blocked area.
• Generally, must be less than 2 miles from
base station/repeater site.
• User doesn’t have to switch channels.
• If planned properly, signal boosters can be
added if needed without wasted investment.
page 5
IWCE 2009
Blocked Signal Solution #6
Install “One-way” Signal Boosters
• Can solve many unbalanced system
problems where either the “talk-out” or “talkin” is OK but the other is unsatisfactory.
• Outside and Inside antenna system is similar
to passive antenna system.
• User doesn’t have to switch radio channels.
• Also applies to in-building 1 way paging.
• Most economical signal booster system.
Blocked Signal Solution #7
Blocked Signal Solution #8
Use Portable Repeaters
Install “TWOTWO-way”
way” Signal Boosters
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Used by some Fire Departments
Can improve coverage up to about 5 floors.
Requires logistical coordination to have at the
right place at the right time.
• Does not work for Simplex fire channels.
• Users may have to switch channels.
• Users may have to ‘learn’
learn’ this may not cover
higher floors in a high rise building.
© Jack Daniel Co, 2008 800-NON-TOLL
• Solves most obstructed site problems,
for “talktalk-out”
out” and “talktalk-in”
in” paths both.
• Outside and Inside antenna system is similar
to passive antenna system.
• Users doesn’
doesn’t have to switch channels.
• The most common signal booster application.
• Multiple Frequency bands can be handled.
• Costs vary, dependent upon frequencies
employed and complexity.
page 6
IWCE 2009
TYPES OF
SIGNAL BOOSTERS
Types of Signal Boosters
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Channelized (FCC Class A)
Broadband (FCC Class B)
One-Way or Two-Way
Single Band ( i.e. VHF, UHF, 800, 900 )
Multi-Band ( i.e. UHF AND 800 )
Customs: Made to specific requirement.
Less common types of signal boosters are;
CUSTOM configured signal boosters may:
- Serve more than one frequency band,
such as UHF + 800, or 450 + 480 MHz, etc.
(System designs may also use more than
one signal booster to obtain multiple bands)
- Used mixed signal booster types, such
as Class B for the Downlink path and
Class A for the Uplink path. These are
sometimes called hybrid signal boosters"
All Emergency Equipment is NOT Equal
_ IN-LINE signal boosters, which extend
distribution coax cable lengths by boosting the
signals at the end of a long coax cable.
Typically this is considered when the
distribution losses at the highest frequency
reach 25 to 30 dB loss.
- ONE WAY signal boosters maybe used for
paging or when only one direction needs
improvement.
© Jack Daniel Co, 2008 800-NON-TOLL
page 7
IWCE 2009
All Signal Boosters are NOT Equal
Cheap Signal Boosters
designed for Consumer
Applications Can and Will
Let you Down at the time
You Need Them Most !
FCC Class A Versus
FCC Class B
Signal Boosters
Basic Definitions:
Class A (channel selective) pass single channels.
Sometimes called ‘channelized’ or channel
selective.
Class B (band selective) pass a ‘window’ of
multiple channels. Sometimes called ‘broadband”
or band selective.
Class A : Primary Benefits
Common Mission Critical (NFPA)
Signal Booster Features:
- Non-vented housings; NEMA 4, 4X
- 12 hour Battery Back-up Compatibility
- Fail-safe redundancy and design.
- Remote Failure Alarming.
- Historical Performance Data.
- Non-Disruptive Testing while in Service.
- Factory Certified Technicians.
- Retuning and Band expansion compatibility.
- Radio technology compatibility; i.e. Delay
FCC Class A Versus FCC Class B
Signal Boosters
Broadband
• Amplifies everything
within a Passband.
• Low cost for many
channels.
• Moderate Output
Power levels.
• FCC Class B
Channelized
• Only amplifies
specific channel(s)
• Moderate cost for
few channels.
• Optional High
Output Power
• FCC Class A
Class A : Disadvantages
- Expensive when compared to Class B.
- Single Channel selectivity can reduce unwanted
signal amplification.
- Modern single channel signal boosters are software
programmable, but not always in the field.
- Gain and AGC can be channel specific
- Some models are available in high power versions,
up to about 25 watts per channel.
- Number of channels per signal booster can be limited,
especially when used in large urban systems.
- Propagation delays may result in poor performance
in signal overlap areas, especially outdoor fill-in
applications. Some models can be reprogrammed to
wider bandwidths and operate as Class B to reduce delay
- Higher back-up power requirements.
- High power models may require site specific FCC
licensing, RF exposure checks, higher antenna isolation.
© Jack Daniel Co, 2008 800-NON-TOLL
page 8
IWCE 2009
Class B : Primary Benefits
Class B : Disadvantages
- Most economical for multichannel systems, many
equipment sources.
- Most commonly used type of all signal boosters
- Very low delay makes ‘modulation transparent’.
- Quality brands compatible with refarming.
Cheap units cannot be retuned.
- Available in all bands including VHF and UHF.
- Bandwidth can allow undesired channels to be
amplified. This is a operational characteristic
that can be addressed in system designs.
- Very strong undesired channels may effect
performance and output power of desired
channels.
- Three grades: Public Safety, Enterprise, Consumer
Session Break
Please stay in the room.
Class continues in 10 minutes
With additional handouts
OVERVIEW OF IMPORTANT
SIGNAL BOOSTER
SPECIFICATIONS
Maximum Input power level
1 dB Compression point
3rd Order Intercept
Signal Booster Specifications Next
MAXIMUM INPUT POWER LEVEL
This specification may seem obvious
but cheap consumer signal boosters
often have very low input power limits.
In quality signal boosters this signifies
input power level where damage may
occur. (This especially applies to RF over
Fiber devices.)
The higher the input power rating the better
© Jack Daniel Co, 2008 800-NON-TOLL
Noise Figure
Propagation Delay
1 dB COMPRESSION POINT
The 1 dB compression point is the Output Level
where an increase of the input level resulted in 1 dB
less than the expected output level.
I.e.: A 2 dB input increase only causes 1 dB output
increase. This indicates the amplifier is no longer
operating in it's linear range.
The 1 dB compression level should be considered
the absolute maximum operating input level to the
signal booster to maintain lowest IM output, under all
input conditions.
The higher the 1 dB compression point the better.
page 9
IWCE 2009
3rd ORDER INTERCEPT POINT
1 dB COMPRESSION POINT EXAMPLE
The 3rd Order Output Intercept Point (3OIP) is a
theoretical level where the 3rd Order IM product
output levels equals the output level of two
fundamental input input carriers.
+ 50
+ 40
1 dB Comp = + 35
GAIN = 80 dB
OLC disabled
OUTPUT
+ 30
+ 20
The 3 OIP specification is needed to prevent IM.
+ 10
3 OIP IM’s are the 2A-1B, 2A+1B IM products.
Note: 2nd Order ( A+B, A-B) are negligible because
they fall outside the passband of the filters and are
attenuated greatly.
0
- 10
- 20
Maximum Input =
+35 - 80 = - 45 dBm
INPUT
-100
-90
-80
-70
-60
-50
-40
3rd ORDER INTERCEPT POINT
ALL amplifiers generate IM,
the challenge is to manage the IM levels.
-30
The higher the 3rd order Intercept point the better
3rd ORDER INTERCEPT POINT
Example: 80 dB gain signal booster
+ 60
3rd OIP = + 55 dBm
IM Level Falls when
the Input Level is
reduced.
Therefore, a 1 dB reduction of the 3rd OIP
specification will increase IM 2 dB.
vel:
3:1
Rat
io
+ 30
+ 20
+10
t
pu
In
0
1
1:
el
v
Le
tio
Ra
utpu
t Le
3 to 1 Rule: Third Order IM will go down 3 dB for
every 1 dB of carrier reduction.
Note how fast the
+ 40
IM O
IM(dBm) = 3*Pout (dBm) - 2*3rd OIP(dBm)
3OIP IM OUTPUT
+ 50
-10
-90
-80
-70
-60
-50
-40
-30
-20
INPUT
NOISE FIGURE
The ‘noise figure’ is a measurement of the
RF noise added to the output signals by
the amplifiers within the signal booster.
Caution: Some manufacturers specify the
ideal amplifier only specifications. Others
provide the ‘true’ input to output noise
figure, which has to be the higher.
The lower the Noise Figure the Better.
© Jack Daniel Co, 2008 800-NON-TOLL
PROPAGATION DELAY
Propagation delay is the time added to the
signal travel time within the signal booster.
High propagation delays can be destructive in
areas where the direct signal meets the signal
booster output signal. This is a primary
concern when using Class A signal boosters.
Propagation delays of 15 microseconds are
currently considered acceptable in any system.
The less the propagation delay the better.
page 10
IWCE 2009
CLASS B SIGNAL BOOSTER SENSITIVITY
Class B signal boosters do not have a input threshold
or 'sensitivity like a repeater has.
NF sets the minimum Input Level.
-174 dBm is the accepted reference for the minimum
natural noise level for 1 Hz bandwidth
Minimum Noise Level (dB) at Input =
- 174 + 10 log(BW) + NF(dB)
(BW = bandwidth in Hertz)
CLASS B SIGNAL BOOSTER SENSITIVITY
Example: Minimum Input for a single channel.
Signal Booster NF = 3.5 dB
Signal Booster Gain = 80 dB
CLASS B SIGNAL BOOSTER SENSITIVITY
The Noise limited minimum Input Level is the
“minimum sensitivity” of a signal booster,
without considering noise from the antenna.
You must add the desired S/N ratio to determine
the minimum possible input signal level.
NOTE: The ambient noise is often greater than
the minimum acceptable input signal level.
CLASS B SIGNAL BOOSTER SENSITIVITY
Output resulting from minimum Input level for a single
channel :
From the preceding example:
- 110.5 dBm Min. Acceptable Input Level
1 Channel Bandwidth = 25 KHz.
Minimum Acceptable S/N = 20 dB ( = 3.4 DAQ )
- 174 + 10 log (25,000) + 3.5 =
- 174 + 44 + 3.5 = - 130.5 dBm ‘noise threshold’
Signal Booster Output level = Input + Gain.
-110.5 + 80 = - 20.5 dBm Output level.
This is a usable signal level for nearby portables, but
marginal for a typical coax distribution system.
- 130.5 + 20 = - 110.5 dBm Minimum Input Level
CLASS B SIGNAL BOOSTER SENSITIVITY
The better way to calculate the ideal input signal level
is to estimate based on maximum output level:
A signal booster with 80 dB gain and +30 dBm output
level at the1 dB compression point ;
+30 - 80 = -50 dbm desired input level.
This input level may not always be achievable.
THE CLASS B
SIGNAL BOOSTER
SOLUTION
Industry practice has established approximately
-75 dBm as the lowest desired signal level.
© Jack Daniel Co, 2008 800-NON-TOLL
page 11
IWCE 2009
COMMON SYSTEM DESIGN COMPONENTS
THE STANDARD IN-BUILDING SOLUTION
ROOF
ANTENNA
DONOR
SITE
SIGNAL BOOSTER
COAX
CABLES
POWER
SPLITTERS
ANTENNA
TAPS
ANTENNAS
SYSTEM DESIGN: BEST PRACTICES:
SYSTEM DESIGN: BEST PRACTICES:
Minimum Signal Level to Portable : - 95 dBm or greater
Minimum Coverage: 90% overall, 95% in critical areas.
ALWAYS USE THE MINIMUM GAIN
AND LOWEST POWER LEVELS
NECESSARY TO
MAINTAIN RELIABLE COVERAGE.
Public Safety “Must Cover” areas:
Fire Prevention and suppression Facilities.
Underground areas Such as parking and basements.
Emergency exit routes, especially stairwells in
high rise structures.
INTERFERENCE MANAGEMENT PRACTICES
INTERFERENCE IN
SIGNAL BOOSTER
SYSTEMS
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Use filters optimized for your system bandwidth.
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Use filters with at least 35 dB rejection of adjacent
bands. i.e. +/- 1 MHz.
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Use directional antennas to reduce signal levels from
other directions and increase desired levels.
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Use the structure to add blockage from unwanted
directions.
Tip: Undesired channels that are -20 dB or more
lower than yours has minimal impact on Class B
signal booster performance.
© Jack Daniel Co, 2008 800-NON-TOLL
page 12
IWCE 2009
Filter Best Practices
Specify the Filter bandpass as narrow as practical.
A 15 or 18 MHz passband used for a 5 MHz
requirement is an invitation for future problems.
Use high performance filters with high selectivity.
A low selectivity 5 MHz filter offers minimal
improvement over 10, 15 or 18 MHz filters.
High Performance bandpass filters are large.
It's physics.
High Performance bandpass filters cost more.
The long term benefits outweigh initial cost.
DONOR ANTENNA
Filter Best Practices
Cheap, consumer grade signal booster
filters are seldom re-tunable.
Signal boosters with 15 or 18 MHz
passbands defeat the effect of 800
rebanding.
FCC Rules may be revised to limit signal
booster bandpasses to the service they
can support. (i.e. Sprint Nextel and other
800 services cannot share the same signal
booster.)
INTERFERENCE FROM OTHER SITES
SELECTION
Always use directional antennas even
when the donor site is near.
The following slides show the advantages
OVER THE AIR INTERFERENCE IMPACT TO YOU:
If system is designed properly, external interference
is not a problem in all but a few extreme situations.
Directional Roof antenna and placement can
dramatically reduce interference.
Public Safety grade Signal Boosters use high
performance filter designs with pass bandwidths
that match your radio system.
Signal boosters that amplify public safety and
cellular at the same time are problematic.
© Jack Daniel Co, 2008 800-NON-TOLL
The impact of undesirable signals on Class
B (band selective) is often exaggerated.
Assuming multiple signal levels of the same level,
here is the relative impact on your output levels
if you have a 10 channel trunked system:
Your 10 channels. Output per channel: + 23 dBm
Add 10 unwanted channels: +20 dBm per channel
Add 30 unwanted channels: + 17 dBm per channel
These are example levels but the impact is the
same relationship for any Class B signal booster.
The desired signals are reduced 3 dB for each
doubling of total channels.
page 13
IWCE 2009
Impact of number of equal power
carriers on a typical Class B signal booster
INTERFERENCE FROM OTHER SITES
1 Carriers: +30.0 dBm per channel
2 Carriers: +27.0 dBm per channel
4 Carriers: +24.0 dBm per channel
8 Carriers: +20.0 dBm per channel
16 Carriers: +18.5 dBm per channel
32 Carriers: +14.0 dBm per channel
40 Carriers: +13.0 dBm per channel
50 Carriers: +10.0 dBm per channel
Tip: Always design for future increases in
undesired carriers within the filter passband.
BEST PRACTICES
DONORSITES
ANTENNAS
INTERFERENCE
FROM :OTHER
INTERFERENCE IMPACT ON OTHERS:
If system is designed properly, external interference
is a non-problem in all but a few extreme situations.
Nearby receiver desense biggest potential problem.
> 500 ft separation eliminates almost all problems.
INTERFERENCE TO OTHERS
CALCULATING BDA NOISE LEVEL IMPACT
REMEMBER, IT IS THE NOISE WITHIN THE RECIEVERS
CHANNEL BANDWIDTH THE RECEIVER SEES, NOT
THE WHOLE BDA BANDWIDTH.
EXAMPLE: BDA WITH 6 DB NF, 60 DB GAIN AND
NO INPUT SIGNAL WILL OUTPUT A TOTAL
BANDWIDTH NOISE POWER OF ~ - 43 DBM
Multi-BDA composite power can only impact nearby
sites normally, using minimum gain and low NF.
THAT CONVERTS TO ~ - 64 DBM IN A 25 KHZ PASSBAND
FCC RULE: ALL In-building is 'secondary' and cannot
cause OBJECTIONABLE interference.
A FREE SPACE SEPARATION OF 60 FEET WILL PROVIDE
-110 DB ISOLATION TO A NEARBY RECEIVER.
© Jack Daniel Co, 2008 800-NON-TOLL
page 14
IWCE 2009
BEST PRACTICES
MULTI-BDA COMPOSITE NOISE TO DONOR
AS THE USE OF BDAS INCREASES SO DOES THE
NUMBER OF BDAS DIRECTED TO THE SAME
DONOR SITE.
THE COMPOSITE (TOTAL) NOISE LEVELS CAN BE
HIGH ENOUGH TO DESENSE A NEARBY DONOR SITE
COMPLEX CALCULATIONS ARE REQUIRED TO PREDICT
THE IMPACT OF COMPOSITE NOISE LEVELS.
SOLUTIONS: LOWER LEVELS AND FEWER BDAS
USING THE NULLS IN
DIRECTIONAL ANTENNA
PATTERNS TO REDUCE
INTERFERENCE
BEST PRACTICES
Directional
Antenna Use
DIRECTIONAL
ANTENNA
CHARACTERISTICS
AND TERMINOLOGY
USING AVAILABLE
PATH BLOCKING TO
REDUCE INTERFERENCE
© Jack Daniel Co, 2008 800-NON-TOLL
page 15
IWCE 2009
USE AVAILABLE
INTERFERENCE
BLOCKING
USE AVAILABLE INTERFERENCE BLOCKING
Panel
Antenna
LOW SITES MAY
BE BETTER THAN
ROOFTOPS
USE AVAILABLE INTERFERENCE BLOCKING
NUMBER ONE CAUSE OF
DESTRUCTIVE
INTERFERENCE TO OTHERS
FROM IN-BUILDING SYSTEMS:
OSCILLATIONS CAUSED BY FEEDBACK.
FEEDBACK MECHANISM: AUDIO SYSTEMS:
FEEDBACK MECHANISM: IN-BUILDING
DONOR
SITE
© Jack Daniel Co, 2008 800-NON-TOLL
page 16
IWCE 2009
FEEDBACK PREVENTION: BEST PRACTICES
ANTENNA ISOLATION TESTING USING SPECTRUM
ANALYZER WITH TRACKING GENERATOR
ROOF
ANTENNA
SPECTRUM ANALYZER
INDOOR
ANTENNA
FEEDBACK PREVENTION : BEST PRACTICES
The MINIMUM Roof Antenna to any inside
antenna isolation must be at least
15 dB greater than the highest operating
gain setting of the signal booster:
Example: Signal Booster gain = + 70 dB
+ 15 dB
Minimum Antenna Isolation read on
spectrum analyzer should be > 85 Db
Newer Digital system designers are specifying
16 to 20 dB isolation.
BEST FEEDBACK PREVENTION REVIEW
- Use minimum reliable gain settings and power levels.
- Use Directional antenna on roof (Donor antenna).
- Don’t place inside antennas near windows or doors.
- Do not use excessive bandwidth, such as public
safety + cellular in one signal booster.
- Select signal boosters with overall low Noise Figures.
ALWAYS HAVE GAIN + 15 dB MINIMUM ANTENNA
TO ANTENNA FEEDBACK PROTECTION.
NEVER RELY ON AGC CIRCUIT OPERATION AS A
SUBSITUTE FOR GOOD SYSTEM DESIGN PRACTICE.
Always Be a Good RF Neighbor
The output noise level of signal boosters can
impact other nearby receivers operating within
the uplink passband.
Some of these receivers may be your own.
If you receive a complaint, be sure everyone is
using appropriate measurement techniques.
A spectrum analyzer based noise power
measurement is only valid if the measurement
bandwidth is equal to the receivers bandwidth
and on the receivers frequency.
Session Break
Please stay in the room.
DESIGN AND
Class continues in 10 minutes
IMPLEMENTATION OF
With additional handouts
IN-BUILDING WIRELESS
DISTRIBUTION SYSTEMS
Signal Booster System Design Next
© Jack Daniel Co, 2008 800-NON-TOLL
page 17
IWCE 2009
THE NEED FOR WIRELESS SIGNAL ENHANCEMENT
IN OBSTRUCTED LOCATIONS HAS BECOME
ROUTINE WITH OTA BDA SOLUTIONS USUALLY
THE "BDA" TECHNOLOGY AND PRACTICE HAS
BECOME MORE PROFESSIONAL AND EXACTING
PROFESSIONAL INTEGRATOR TRAINING HAS
GROWN, WITH FORMAL CERTIFICATION SCHOOLS
OVER THE LAST 3 YEARS, SUCH AS THE GES
PROGRAM
THE OBJECTIVE IS BETTER
WIRELESS COVERAGE
THE CHALLANGE IS TO USE THE
MINIMUM
RELIABLE SIGNAL LEVELS
EVERYWHERE YOU NEED IT
http://www.bird-technologies.com/training/inbuilding_coverage.pdf
BASIC SYSTEM DESIGN CONSIDERATIONS
1. SUFFICIENT SIGNAL LEVELS
FROM DONOR TO BDA - DOWNLINK
FROM INDOOR ANTENNA TO PORTABLES
FROM PORTABLES TO BDA - UPLINK
FROM BDA TO DONOR SITE
2. EFFICIENT IN-BUILDING DISTRIBUTION
DISTRIBUTED ANTENNA (DAS)
ADVANCED SYSTEM DESIGN CONSIDERATIONS
- BROADBAND DISTRIBUTION SYSTEM CAPABILITY
FOR MULTI-BAND AND FUTURE CHANGES
- INTERFERENCE TO YOU
UNDESIRED INBAND CARRIERS
INPUT OVERLOAD (3IOP POINT, AGC RANGE)
- INTERFERENCE FROM YOU
FEEDBACK - OSCILLATIONS
OUT OF BAND NOISE
BDA GENERATED I.M.
3. MINIMUM RF POWER REQUIREMENTS
THE OLD “BDA” INDUSTRY HAS CHANGED.
MODERN IN-BUILDING SYSTEMS
ARE CALLED
DISTRIBUTED ANTENNA SYSTEMS
OR “DAS” INSTALLATIONS
CHANGES IN SYSTEM DESIGNS
- Distributed Antenna Systems (DAS) now dominate
over Radiating cable.
- Indoor antenna patterns are better controlled.
- Broadband and multiband passive distribution
components (antennas, splitters, decouplers, etc)
- Signal boosters are more serviceable and rugged.
- "Smart" BDAs are becoming common.
- RF over Fiber use is expanding rapidly.
© Jack Daniel Co, 2008 800-NON-TOLL
page 18
IWCE 2009
CHANGES IN SYSTEM DESIGNS
Mission Critical applications are now
demanding RF distribution system designs
including:
- Compatibility to Current and future digital
Modulation types (Including TDMA)
- 800 Retuning capability
- Minimized Multipath delay, especially for data
- Remote Control , Test and Alarms via PSTN,
modems and Internet type protocols.
In DAS, standard non-radiating cable is used
and antennas are placed at intervals using
decouplers.
DAS antennas have less loss than radiating
coax due to high 'coupling loss' of radiating
cables.
Radiating cable can be cheaper than DAS
but more cable may be required to get
coverage equal to DAS.
RADIATING COAX CONSIDERATIONS
Radiating cable installations can be less expensive
than DAS due to the cost of decouplers, antennas
and connectors used in DAS.
Radiating cable is often the best choice when
coverage is 'linear' as in a tunnel.
When there are sufficient RF levels, Radiating cable
can cover large distances perpendicular to the cable.
it is not limited to 20 feet. For example,
20' coupling loss = -65 dB
40' adds 6 dB = -71 dB
80' adds 12 dB = -77 dB
© Jack Daniel Co, 2008 800-NON-TOLL
COAXIAL CABLE
DAS
TECHNIQUES
RADIATED POWER COMPARISON
DAS VESRSUS RADIATING COAX
> Radiating Cable: - 65 dB coupling loss at 20 feet.
> DAS using -10 dB decoupler :
- 10 dB plus 20 ft. free space loss = 10 = 46 = 56 dB
The DAS -10 dB decoupler reduces through loss by
-1 dB each and Radiating cable through loss is
at least -1 dB /100 ft more than non-radiating cable,
DAS will have 10 dB advantage when DAS antennas
are placed at 100 ft intervals. (Based on 800 MHz)
The DAS advantage is even greater at VHF and UHF.
IN-BUILDING ANTENNAS
Antenna types and location can greatly influence
how a DAS works.
Past techniques are often compromises that are
no longer necessary.
The driving coverage concept is;
Put just enough signal level to have reliable
coverage every place you need it.
Brute force designs are wasteful and often give
inadequate coverage and create interference.
page 19
IWCE 2009
IN-BUILDING ANTENNAS
IN-BUILDING ANTENNAS
One common mistake is the location of antennas.
Placing the antenna at user height can cause the
uplink signals to exceed the dynamic range of a BDA
as the user moves from the end of the path to near
the antenna.
Raising the Antenna as much as possible increases
the distance to the user near the antenna and stabilizes
RF levels over the whole coverage pattern.
WAVE FRONT REINFORCEMENT
2
1
LOW ANTENNA: #1 = 200' = - 66 dB #2 = <20' = - 46 dB
DYNAMIC RANGE = 20 dB
2
1
HIGH ANTENNA: #1 = 200' = -66 dB #2 = 40' = - 52 dB
DYNAMIC RANGE = 14 dB
IN-BUILDING ANTENNAS
TOWER
INSIDE ANT
- Multiband : VHF + UHF + 800
- Low Profile : Garages, Tunnels, etc.
- Very low profile : Centaurian
INSIDE ANT
- Indoor Panel
- Indoor Directional
POWER DIVIDERS, COUPLERS AND TAPS
The old practice of using 50:50
power splitters to branch off a
coax cable is an obsolete
practice.
Different ratios are available that
will better distribute even power
levels.
POWER DIVIDERS, COUPLERS AND TAPS
- Available in many different values, split ratios;
- 3 dB = 5O:50 % split
- 4.8 dB = 33:67 % split
- 6 dB = 25: 75 % split.
- 10 dB = 10: 90 % split
- 20 dB = 1: 99% split
- 2 way power splitting may be wasting RF power.
- Broadband and Harmonic Hybrid decouplers.
- Taps, impact on in-line losses:
- 10 dB = 0.5 dB thru loss
NEVER USE "T" CONNECTORS AS SPLITTERS.
© Jack Daniel Co, 2008 800-NON-TOLL
page 20
IWCE 2009
Basic RF over Fiber Distribution Advantages
1. Lower installation costs compared to coax.
Materials
Routing
Haz Mat avoidance
RF-OVER-FIBER
TECHNOLOGY
2. Lower RF loss than coaxial cable:
Increases the area of coverage per BDA
Can feed distant buildings
3. Very Broadband:
Can be RF frequency insensitive.
Expansions easily accommodated.
122
Definitions
RF Over Fiber Basics: Transmitters
1310 and 1550 nm:
Optical frequency in nanometers. 1310 and 1550 are
the most common and economical for RF over Fiber
circuits.
DATA IN
FO OUT
RF IN
ANALOG FIBER OPTICS, NOT DIGITAL
123
Basic BDA/Fiber DAS System
RF Over Fiber Basics: Receivers
RF to FO
DATA OUT
FO Cables
RF OUT
FO to RF
FO IN
© Jack Daniel Co, 2008 800-NON-TOLL
page 21
IWCE 2009
Basic BDA/Fiber DAS System
Basic Fiber Distribution Concepts
Point to Point system: 2 fibers
1310 nm
Uplink OUT
Optical TX
Uplink IN
Optical RX
fiber optic cables
Optical RX
Downlink IN
Optical TX
1310 nm
Downlink OUT
INTERFERENCE
YOU
Basic Fiber FROM
Distribution
Concepts
Basic Fiber Distribution Concepts
Point to Point system: 1 fiber
An in-building fiber based BDA- DAS system
does NOT :
Uplink OUT
1310 nm
Optical TX
WDM
1310 nm
Optical RX
fiber optic cable
Optical RX
Downlink IN
1550 nm
Uplink IN
WDM
- Solve the feedback concerns.
- Solve Interference issues.
Optical TX
1550 nm
Downlink OUT
And it may not be the most cost effective
solution for general applications.
The TX , RX and WDM are in a common housing.
(WDM = Wavelength Division Multiplexer)
Basic Fiber Distribution Specifications
Basic Fiber Distribution Specifications
Approximate End-to-end Distances:
RF Power Levels: In and Out
~ - 75 to + 6 dBm
Total allowable loss : 10 dB
Connector loses: 2 dB
Net Gain, end-to-end: +/- 3 db, typical
Fiber loss budget: - 9 to - 10 dB, typical
Dynamic Range : 85 dB
Noise Figure 45 dB
3rd OIP: + 29 dBm
© Jack Daniel Co, 2008 800-NON-TOLL
Fiber allowance: 8 dB loss
Fiber attenuation:
- 1310 nm : 0.8 - 1.2 dB/mile (0.5 - 0.8/Km)
- 1550 nm : 0.3 - 0.5 dB/mile (0.2 - 0.3 dB/Km)
Fiber length for 8 dB loss:
- 1310 nm @ 0.8 nom. = 10 miles (16 Km)
- 1550 nm @ 0.4 nom. = 20 miles (32 Km)
page 22
IWCE 2009
Basic Fiber Distribution Specifications
Basic Fiber Distribution Specifications
Propagation Delay has become an important
Specification for simulcast and digital systems.
Fiber Optic Cables do NOT radiate RF.
Fiber Delay: ~ 5 uS/Km ~ 8 uS/mile
(60% speed of light)
Single Mode type fiber is used in
almost all RF over Fiber systems.
RF - Fiber Transceivers: ~ 5 uS total, end-to end.
APC (Angle Polished Connectors) are
always used and not mixed with any
other type anywhere in the system.
Fiber transceivers have sub-microsecond delays,
therefore the maximum fiber length that keeps delay
less than 15 uS is approximately 2miles.
Basic RF Over Fiber Transceiver
RF over Fiber Transceivers
RF In
Fiber Out
Power, Data,
Alarms
Fiber In
RF Out
Most Common Arrangement
TX & RX may be in common case
Note: Can Use Same Optical Freq. Both ways.
RF over Fiber Transceivers
Fiber Distribution Components
Splice Tray
Protects Splices
Patch Panel
Protects Main Cable
Facilitates Testing
Note: Different Optical TX Freq.s
© Jack Daniel Co, 2008 800-NON-TOLL
Splice Tray and Patch Panel can be one assembly
page 23
IWCE 2009
Multiple Transceiver Shelves
RF over Fiber Distribution Connectors
Cable Connectors are always Males
SC-APC Type
FC-APC Type
Important Color Codes:
Cables: Yellow = SM / Orange = MM
Connectors Body: Green = APC / Blue = PC
Head end unit: supports 1 to 5 remote units
ALWAYS USE SM CABLE !
Multiple Transceiver System
Direct To Donor Interface
TX Ant
RX Ant
-50 dB Directional
Coupler
Repeater
TX’s
Repeater RX’s
Special Systems: Remote BDA
Optical
TX
Optical RX
-80 dB Directional
Coupler
Special Systems: Campus
Direct
to Donor
DONOR
SITE
No outside
Interference
No Blockage
Resolves
Interference
Feedback
& Blockage
© Jack Daniel Co, 2008 800-NON-TOLL
No Feedback
page 24
IWCE 2009
Special Systems: Campus
Special
Systems:
Campus
96 DAS
Antennas
900 MHz
two-way &
paging
First of two
towers
DEFINITION: NEUTRAL HOST SYSYEM
Neutral host is a term used to describe
Wideband DAS systems that have the
Capability to be ‘neutral’ to several
different cellular, PCS, WiFi carriers
SHARED SYSTEMS
a.k.a Neutral Host Systems
In this context “carrier” is a for-profit
service provider, not private licensees.
147
148
"Neutral Host" Systems
NEUTRAL HOST SYSTEM
Large privately owned buildings may have an
elaborate cellular, PCS and WiFi distribution system.
These system are designed to make a profit for
the system owners based on the air time used by
The public (consumers) within the building.
Antenna 1
Cellular A
There is nothing wrong with this type of system
HOWEVER, there may be problems when you try
to add private radio/ public safety channels
to existing neutral host systems.
Cellular B
Common
PCS
Distribution
Wi Fi
149
© Jack Daniel Co, 2008 800-NON-TOLL
This is a system designed to reduce costs by
sharing the distribution system with multiple
cellular and PCS services. Some are trying to
adapt this concept to public safety.
Antenna 2
Antenna 3
150
page 25
IWCE 2009
"Neutral Host" Systems
Neutral Host Priority : Profit
Basic Rule:
Use the minimum amount of equipment investment
and cover the least amount of area that will provide
The maximum income per investment dollar.
Using this concept for Public Safety becomes
more difficult when VHF and UHF channels are
distributed.
Common
UHF
This means NOT having back-up power or covering
areas where there is little routine public travel.
Antenna 1
800
NPSPAC
Antenna 2
Distribution
VHF
Antenna 3
After hours maintenance is not required or offered.
Tomorrow is considered good repair service for
Consumers.
System can be altered to make more profit.
151
Mission Critical Priorities
152
Technical Incompatibilities
Basic Public Safety Rule: Providing life critical
coverage is more Important than costs.
The way cellular systems operate is much
different than public safety radio systems.
Coverage is needed where first responders, employees
and the public go, including emergencies.
Reliability and survivability requires power back-up,
Redundancy, and public safety grade equipment.
Serviceability includes 27/7 access to the system. the
ability to alter the system in an emergency and
pre-incident fault monitoring.
Cellular has relatively low power handsets and
Some ‘drop-outs’ are accepted.
Public safety handsets are much more powerful
and can overload a system designed for cellular.
Overloading can generate interference (IM),
distortion and loss of data.
153
Technical Incompatibilities
Operational Incompatibilities
The frequencies used can interact.
Mission Critical users on shared systems should:
For example, the high end of NPSPAC channels
are immediately adjacent to Cellular A band and
parallel signal boosters will disrupt both systems.
- Be aware of system accessibility. A Shared system
may require coordination and approval of multiple
carriers, building owners, etc. Access may take days or
weeks.
After 800 rebanding there will be interaction
between Cellular B and public safety.
Filters in cellular signal boosters are lower
performance than those used in public safety rated
signal boosters. (That’s one reason consumer
grade cellular boosters are cheaper)
Combinations of the two bands can generate
destructive intermodulation.
155
© Jack Daniel Co, 2008 800-NON-TOLL
154
- System coverage maintenance. Cellular engineers
may change coverage to meet their needs without
notification or agreement with the non-cellular user,
losing critical non-cellular coverage.
- In an extreme situation, the mission critical user
should be able to shut down the system when it causes
interference.
156
page 26
IWCE 2009
Common "Neutral Host" Systems
Outdoor Fill-In Coverage
The majority of new Neutral Host systems use
fiber distribution because of the bandwidth.
When industrial and/or public safety channels
are required, it is becoming best practice to
install a separate DAS system at the same time.
Remember: Signal Boosters may NOT
be used to extend coverage legally.
Separate DAS system antennas are spaced 50’
or more apart.
157
Fill-In Coverage
OUTDOOR COVERAGE ANTENNA ISOLATION
© Jack Daniel Co, 2008 800-NON-TOLL
BEST PRACTICES
Fill-In Coverage Optimization
page 27
IWCE 2009
BEST PRACTICES : FILL-IN COVERAGE
Fill-In Coverage
- Use Directional antennas for better vertical
antenna-to-antenna isolation.
- Control service area antenna pattern to reduce
out of area signals.
- When using Class A (channelized) signal boosters,
propagation delay differential in coverage
overlap zones can be excessive. Differential delays
over 15 uS can be problematic.
- Use minimum gain and minimum output power
to obtain antenna – antenna isolation.
What is a Signal Booster (BDA) ?
FCC RULES FOR
PART 90
LICENSEES
FCC Rule Summary : Part 1
• A Signal Booster is a highly specialized R.F.
Amplifier designed to boost weak radio
signals and distribute radio signals within an
otherwise obstructed area of coverage.
• FCC Rules (90.219) allow Part 90 licenses
to use Signal Booster without additional
licensing, subject to certain conditions.
FCC Rule Summary : Part 2
The FCC has two classes of Signal Boosters;
1. Only users with FCC licenses are
authorized to use signal boosters.
Class A: Commonly called Channelized or
channel selective.
2. The maximum output power under this
rule is 5 watts ERP. Higher power
must be licensed as a station.
Class B: Commonly called Broadband or
band selective.
ALL signal boosters used in Part 90 must be
FCC certified.
© Jack Daniel Co, 2008 800-NON-TOLL
3. Mobile signal boosters are NOT
authorized.
4. Signal Boosters are ‘secondary’ use
and must not cause interference.
page 28
IWCE 2009
Codes and Ordinances
Used to Provide In-Building
Wireless Communications
For Public Safety Agencies
within Privately Owed
Structures.
Jurisdictions with Local Signal Booster Codes
- City of Burbank
- City of Roseville CA
- City of Scottsdale AZ
- City of Ft. Lauderdale FL
- Hampshire (Illinois) FPD
- City of Broomfield CO
- City of West Hartford CT
- City/County of Sacramento
- City of Riverside CA
- City of Sparks NV
- Mercer Island WA
- Muskego WI
- City of Folsom
- City of Ontario
- City of Tempe AZ
- Grapevine TX
- City of Sparks NV
- City of Boston MA
- City of Irvine CA
- City of Tempe AZ
- Sarpy County NE
- City of Glendale CA
- City of San Jose CA
- Richmond VA
Local Ordinances and Codes requiring
In-Building coverage is no longer
unusual.
An estimated 200 jurisdictions have
some form of local requirement with
more under development.
As a result, de facto standards are
being established and nation wide
codes are not too distant in the future
National In-Building Code Developments
Driver:
NIST Post 9-11 WTC report Recommendation # 22;
Installation, inspection and testing of ….radio
communications...: (1) are effective for large scale
emergencies in buildings with challenging radio
frequency propagation environments.
This report, and other factors such as fire responders
input, are driving rapid efforts towards common,
nationwide in-building communications standards.
and more
National Fire Protection Association (NFPA)
- NFPA has developed national in-building codes.
- Codes enable local adoption and uniformity.
International Code Council (ICC)
- These new codes appear as International Fire
Code (IFC)
- Nationwide impact
- These codes are the primary fire code for
almost every city in the U.S.
- Signal booster hardware to meet minimum
standards and operational specifications.
- Signal booster hardware to meet minimum
standards and specifications.
- Primary fire codes effected: NFPA-1 and NFPA 72
- Compatible with NFPA code.
- Compatible with IFC codes (next slide)
- Code effected: New IFC Section 511 and
Appendix I.
© Jack Daniel Co, 2008 800-NON-TOLL
page 29
IWCE 2009
New Code Provisions
Newer Code Provisions
Qualified design and installation personnel
- 12 hour battery or local generator backup.
- Must be certified by the equipment
manufacturer or some recognized authority,
subject to the agencies approval.
- Non-interference.
Prequalified equipment manufacturers
Other in-building wireless systems cannot
degrade public safety communications.
- Must meet tighter technical specifications.
New Code Provisions
Public Safety Frequency changes, expansions.
- Owner is advised public safety spectrum
changes may occur over time due to FCC rule
changes and the public safety in-building
system must be modified or replaced as
required.
Notable examples are;
- 800 MHz 'rebanding'. Shifts many 800 MHz
public safety frequencies.
- New 700 MHz public safety channels. Will be
added eventually to almost every urban public
safety system.
Costs to Private Property Owners
New Code Provisions
NFPA code: alarms sent to local fire panel:
- Amplifier failure.
- AC power failure.
- DC power failure.
- Antenna circuit failure.
Optional Remote Access Capability:
- Pager alert of failure or oscillation.
- Dial-up control.
- Intranet/Internet control and alarms.
- Remote adjustments.
National Public Safety Telecommunications
Council (NPSTC)
Exact costs are dependent upon many variables;
size and type of structure, frequencies required,
local electrical/union codes, etc.
This group is NOT writing codes, but has issued
an In-building “Best Practices” White paper last fall.
The Building Owners and Managers Association
(BOMA) recently cited costs up to $1.50/sq ft.
These are usually neutral host type systems.
The NPSTC paper reflects much of the new code
requirements and endorses the efforts of NFPA
and ICC.
More typically, public safety only system costs
range down to as low as $0.25 per square foot.
© Jack Daniel Co, 2008 800-NON-TOLL
The NPSTC paper is widely accepted within the
Public Safety community and by others, such as
federal groups.
page 30
IWCE 2009
Additional Resources………..
- FCC : www.fcc.gov
- National Fire Protection Association (NFPA)
www.NFPA.org
- International Code Committee (ICC)
www.ICCsafe.org
- National Public Safety Telecommunications Council
www.NPSTC.org
- Free material available from Jack Daniel Company
www.RFSolutions.com:
* 40 + On-line local code examples
* In-Building code white paper
* Model universal in-building code
* Signal booster educational material
© Jack Daniel Co, 2008 800-NON-TOLL
Thank You
Jack Daniel, member;
APCO International
NFPA In-Building Code task force
ICC In-Building Code task force
Vice-Chair, NPSTC In-Building committee
800-NON -TOLL
www.RFSolutions.com
© 2008 All rights reserved
page 31