repeater doc
TRANSCRIPT
-
7/30/2019 Repeater Doc
1/37
Repeaters
Topics
1. Introduction to Repeaters
2. Repeater Setup Considerations3. Procedure in Repeater Cell Setup
4. Repeater Block Diagrams
5. Frequency Shift Repeater
6. Optical Repeater
Repeaters 2
-
7/30/2019 Repeater Doc
2/37
IntroductiontoRepeaters
Repeaters 3
RadioRepeaters
Radio repeaters, or Bi-Directional Amplifiers (BDA)
Works as a bi-directional amplifier to increase the signalbetweenmobiles and base stations, in uplink and downlink direction.
Used for an area with poor coverage in outdoor and indoorenvironment, or for coverage enhancements in areas
blocked byobstacles.
Uses a pick up (donor) antenna to receive and amplify theradio
signal from a donor cell, and then retransmit from anantenna
mounted near the area to be covered.
Complete local monitor function and powerful remoterepeater
network administration (OMC).
Typical applications include
Indoor : conference centre, shopping mall, office building.
Radio shadow areas : underground car parks, tunnels,
valleys. Coverage extension : motorways.
-
7/30/2019 Repeater Doc
3/37
Repeaters 4
-
7/30/2019 Repeater Doc
4/37
TypicalRepeaterSetup
BTS
Donar antenna
Repeater
Service area antenna
Repeaters 5
Off-AirRepeaterApplication
DonorANT
ServiceANT
BTSRepeater
RepeaterBTS Coverage Coverage
Extension of BTS Coverage
Repeaters 6
-
7/30/2019 Repeater Doc
5/37
BenefitsofaRepeater
Fast rollout and fast coverage leads to fast return on investment
Low build out costs
No microwave link and No 2 Mbit- connection needed Less antennas and cable usage, and smaller space required
for equipment.
Easy to locate site for installation & coverage
Expands coverage areas in: rural, tunnels, in-building, canyons and
highways
Platform for subscriber growth
Acts just like base station
Repeaters 7
TypesofRepeater
Band Selective / Broadband
Pico repeater - Good forproviding indoor coverage
such as office, meeting room,
function room and stairway
etc.
In-line Booster - Boost signal
power in feeder cables.
Bandwidth Adjustable
Suitable for Inbuilding
coverage. Outdoor coverage in rural and
sub-urban areas.
dB Typical7 MHz Typical 25 MHz
0 -3
-40
Centrefrequency
dB 390kHz Operator's band
0-3
-40
Centrefrequency
Typical7 MHz
Frequency
390kHz
Frequency
Repeaters 8
-
7/30/2019 Repeater Doc
6/37
TypesofRepeater
Channel Selective
Suitable for providing
coverage in high rise
buildings.
Outdoor coverage in urban
areas where frequencies
reuse is tight.
Hybrid Repeater
Suitable for use in
synthesize frequency
hopping network.
dB
0 -3
-40
dB
0-3
-40
approx200 kHz
190
approx200 kHz
190 190 FrequencykHz kHz
390 Operator's 390kHz TCH band kHz
Centre Frequency
190kHz kHz
frequency
Repeaters 9
RepeaterSystemComponents
BDA
To BTSYagi Panel
antenna antenna
To MSservice area
coaxial coaxial
Batterybackup
Repeaters 10
-
7/30/2019 Repeater Doc
7/37
DonorAntennas
Donor antenna must be directed towards the donor cell (LOS) so
that there is
stronger received downlink power from
BTS.
minimum downlink amplification needed.
minimum spurious or interfering signals;i.e. higher C/I.
stronger uplink signals to the BTS.
Repeaters 11
DonorAntenna
Popular belief that Yagis are best fitted as a donor antenna.
Yagis have low gains and high horizontal sidelobe
levels.
Radiation pattern of a typical 12 dBi Yagi antenna
Repeaters 12
-
7/30/2019 Repeater Doc
8/37
DonorAntenna
30 - 40 corner reflector or log-periodic antennas are better suited
with higher gain (~18dBi) and F/B ratio (> 40dB).
Radiation pattern of a 30 degree, 18 dBicorner reflector antenna
Repeaters 13
DonorAntenna
Grid Parabolic Antennas are best suited for repeater applications.
Very high gain : 18 ~ 25 dBi Narrow beamwidth : < 10 deg
Radiation pattern of a typical 23 dBi
grid parabolic antenna
Repeaters 14
-
7/30/2019 Repeater Doc
9/37
ServiceAntenna
Planar antenna with broad radiation pattern, depending
on requirements
lower gain antenna gives broader vertical
beamwidth. use radiating cable for better vertical
fill.
Antenna is directed to the center of the coverage area.
For tunnels, use Yagi antennas.
For indoor, use special indoor antennas.
Use minimum 7/8" coaxial cable to minimize loss
Repeaters 15
OutdoorRepeaterApplications
Most Repeaters Systems are interfaced with the common Outdoor
and Indoor applications. We integrate Channel Selective Repeaters
and Band Selective Repeaters to give coverage in rural and urban
areas.
Repeater coverage for a main road Island Coverage when microwave linkis not possible / available
Repeaters 16
-
7/30/2019 Repeater Doc
10/37
TypicalCoverageImprovements
Blk
135
Blk
135
Before After
Repeaters 17
RepeaterSetupConsiderations
Repeaters 18
-
7/30/2019 Repeater Doc
11/37
AntennaIsolation
A repeater can act as an oscillator if the signal feedback is greater
than the gain.
Isolation between donor & service antenna should be atleast
10 - 15 dB more than system gain.
Fair distance from donor antenna for proper isolation is
estimated
to be 10-15m vertical spacing.
To measure, inject a known power into one antenna
(or use tracking
generator function),
& measure the
level received bythe other on aspectrum analyzer.
Donor
isolation
Spectrum ServiceAnalyzer
Repeaters 19
FactorsAffectingIsolation
Antenna Pattern
Antenna null should be pointing towards the other
antenna.
Donor and Service antennas should have high F/B
ratio.
Vertical Separation
Narrow vertical aperture in the vertical antenna pattern.
Environmental Separation
Reflection and attenuation properties of materials near the
antenna
can influence isolation drastically.
Concrete towers improves isolation as signals are attenuated
and
reflected.
-
7/30/2019 Repeater Doc
12/37
Repeaters 20
-
7/30/2019 Repeater Doc
13/37
EffectiveDonorPathLoss(EDoPL)
ERP Donor RepeaterService
PLBTS-RR
PLRR-MS(max)Lcoax Lcoax
PLRR-MS(min)EDoPL
BTS MSmin MSmax
This comprises all losses and gains between the BTS output and
the donor port of the repeater.
EDoPL is assumed to be equal for uplink and downlink.
EDoPL can be found by
checking with the Switch the BTS power setting, PBTS; connecting a spectrum analyzer to the end of the donot
cable
and reading the received level, Pin-rr;
EDoPL = PBTS - Pin-rr
Repeaters 21
EffectiveDonorPathLoss(EDoPL)
The uplink noise level arriving from the repeater to the BTSNu = Nth-rr + Grr + NFrr - EDoPLwhere
Nth-rr = thermal noise of a GSM channel (-121 dBm @ 20C)Grr = uplink gain setting of repeaterNFrr = repeater noise figure (typ 5 to 9 dB)
To minimize noise interference at the BTS, let Nu be 3 dB less than
thermal noise of BTS, Nth-bts;i.e. Nu = -(121+3) = -124 dBm.
Assuming NFrr = 7 dB,the maximum repeater gain setting is determined by
Nu = Nth-rr + Grr + NFrr - EDoPL-124 = -121 + Grr + 7 - EDoPL
Grr = EDoPL - 10
Repeaters 22
-
7/30/2019 Repeater Doc
14/37
RepeaterSaturation
Downlink
Repeater input power (Pin) is too strong
Pin (dBm) => Pout (dBm) - Minimum Gain(dB) May need external attenuator
Repeater Gain set too High
Maximum Gain (dB) 9dB or
delay spread is less than 15.5 s.
Placing the repeater between the donor BTS and theservice
area satisfies this requirement.
-
7/30/2019 Repeater Doc
15/37
Repeaters 24
-
7/30/2019 Repeater Doc
16/37
Interference&Handover
Band selective repeaters must be used with caution onsites close to the cell border
Signal strength of donor and adjacent cells are close. May result in some calls being originated at an adjacent
cell
but outside its cell borders.
Donor antenna performance is important.
Problem do not occur for channel selective repeaters
Only the chosen GSM channels are repeated.
Superior to band selective for outdoor large area coverage.
Repeaters 25
ImportantRepeaterSpecifications
Broadband, Band Selective, Channel Selective, Hybrid.
Number of channels.
Output power per carrier.
Maximum gain and adjustable range.
Noise figure.
Automatic gain control.
Spurious emission : 36 dBm in G9 band (ETS 300342).: 30 dBm in G18 band
Mean Time Between Failure (MTBF).
Other features remote connection via PSTN or GSMmodem. Interface to OMC.
Repeaters 26
-
7/30/2019 Repeater Doc
17/37
RepeaterSiteSelection
Good LOS (Line Of Sight) with donor cell and intendedcoverage
area.
Good donor signal level received at site.
Example: A repeater with maximum 95dB gain and 37dBmoutput
power requires a minimum input signal of -58dBm toproduce max
output power.
Sufficient antenna mounting space for good isolation.
Good air ventilation with shelter (preferred).
Easy access to repeater.
Repeaters 27
ProcedureinRepeaterCellSetup
Repeaters 28
-
7/30/2019 Repeater Doc
18/37
StepsInSettingUpRepeaterCell
Pre-Installation Drive Test
Repeater Design
Repeater Installation
Repeater Commissioning
Post-Installation Drive Test
Optimization
Repeaters 29
Pre-InstallationDriveTest
Determine drive test route for existing coverage area.
Identify weak spots. Repeater Coverage Design
Before
Repeaters 30
-
7/30/2019 Repeater Doc
19/37
RepeaterInstallation
Optimize Donor Antenna
Spectrum Analyzer Service
Donor
Isolation Measurement
isolation
Configure Repeater
Test Calls
Optimize Coverage
Repeaters 31
RepeaterInstallation
Optimize Donor Antenna
Direct Donor antenna towards donor cell. Scan for optimum donor carrier strength using spectrum
analyzer.
Adjust antenna until maximum donor signal strength is
achieved.
Measurement of Coupling Loss (Isolation)
Measure the signal received by the other antenna on aspectrum
analyzer.
Isolation (coupling loss) is the difference between the 2power
levels.
Inject a signal of known power level into one antenna.
Configure Repeater
Set to carrier frequency/bandwidth.
Adjust Attenuation to achieve optimum DL & UL output
power. Set appropriate threshold for alarms.
-
7/30/2019 Repeater Doc
20/37
Repeaters 32
-
7/30/2019 Repeater Doc
21/37
RepeaterInstallation
Test Calls
Calls set up and voice quality.
Test for any abnormal drop calls.
Handovers between neighbour cells.
Optimize Service Antenna Orientate antenna to achieve desired network coverage.
Repeaters 33
Post-InstallationDriveTest
Perform drive test on pre-determined route.
Verify coverage enhancement at weak spots. Optimize repeater coverage
Repeater Cell
Blk135
After
Repeaters 34
-
7/30/2019 Repeater Doc
22/37
ImpactonDonorCell
Enhanced network coverage at affected areas.
Increase in cell traffic.
Possible congestion due to increase in traffic. Higher handover in donor cell due to increase in traffic.
Higher drop calls due to more handover and traffic congestion.
Repeaters 35
RepeaterBlockDiagrams
Repeaters 36
-
7/30/2019 Repeater Doc
23/37
ChannelSelectiveRepeater
ALC
C-ATT
PA1
M-ATT
LNA1
40dB
Downlink
-30dBTest
Donor Ant
DT
C-ATT
PA3 20dB
PA4 C-ATT
20dB
OMT UL Freq SelectComputer with Data card Module
Alarm
Modem IndicatorWireless Modem
OMC
Channel Filter 20dB
f1 f1
ALC
C-ATT PA2
20dBChannel
f2 Filter f2 DLF req Select Module Mobile
ALC MT Ant
-30dB Test
Channel Mobile
f1 Filter f1 M-ATT
ALC 40dB LNA2
Uplink
Channel
f2 Filter f2
Main Control Unit Power Li-ionSupply BATT
External Power
OMT
Repeaters 37
BandwidthAdjustableRepeater
ALC
M-ATT C-ATT
LNA1 PA1
Band Band
Test Downlink f1 Filter f1 f2 Filter f2Donor DL Freq Select Module Mobile
Ant Ant
DTALC Test MT
C-ATT M-ATT
PA2 LNA2
Band BandUplink Mobile
f2 Filter f2 f1 Filter f1UL Freq Select Module
OMT Alarm Power Li-ionComputer with Indicator Main Control Unit Supply BATT
Data card Modem
Wireless Modem
External Power
OMC OMT
Repeaters 38
-
7/30/2019 Repeater Doc
24/37
BandSelectiveRepeater
ALC
M-ATT C-ATTCDMA Freq
CDMA Freq LNA1 PA1 FC1, FC2FC1, FC2 30dB Band 15dB
-30dB Downlink f1 Filter f1fC1, fC2 Test fC1, fC2
Donor DL Freq Select MobileAnt Module Ant
ALC -20dB Test
C-ATT M-ATT Mobile
PA3 LNA2
15dB Channel 30dB
f2 Filter f2 Uplink
UL Freq Selectand PA Module
OMT Computer withData card Alarm Power Li-ion
Modem Indicator Main Control Unit Supply BATT
Wireless Modem
External Power
OMC OMT
Repeaters 39
HybridRepeater
ALC
C-ATTPA1
-
7/30/2019 Repeater Doc
25/37
-30dBTest
-
7/30/2019 Repeater Doc
26/37
M-ATT
LNA1
40dB
Downlink
-
7/30/2019 Repeater Doc
27/37
20dB
C-ATT
20dB
-
7/30/2019 Repeater Doc
28/37
f1
-
7/30/2019 Repeater Doc
29/37
Band BandFilter f1+fo f2 Filter f2+fo
DL Band Freq Select Module
ALC
PA2
Channel
f3 Filter f3+fo DL Channel Freq
OMTComputer with
Donor Ant
DT
PA3
ALC
Band Band
f2+fo Filter f2 f1+fo Filter
UL Band Freq Select Module
ALC
PA4
Channel
UL Channel Freq f3+f o F il ter
f1
Select Module
C-ATT
20dB
C-ATT
20dB
M-ATT
LNA2
40dB
Downlink
-30dBTest
MT
Mobile Ant
Mobile
Data card Select Module f3
Wireless Alarm IndicatorMainControl Unit
P owe r S uppl y L i- io nBAT T
Modem Modem
External Alarm Sensors
OMC
External Power
OMT
Repeaters 40
-
7/30/2019 Repeater Doc
30/37
IndoorBandSelectiveRepeater
ALC
M-ATT
LNA1 PA1
30dB Band
-30dB Downlink f1 Filter f1+fo
DonorTest
DL Freq Select and PA Module Mobile
Ant Ant
DT ALC MT
M-ATT
PA2 LNA2
Band 30dB Mobile
f1+fo Filter f1 Uplink
UL Freq Select and PA Module
OMT Computer with Power Li-ionData card Alarm Indicator Main Control Unit Supply BATT
Wireless Modem
Modem
External Alarm Sensors
OMC External Power 220VAC
OMT
Repeaters 41
IndoorWidebandBooster
ALC
M-ATT
LNA1 PA1
Downlink
Donor Mobile
Ant Ant
DT MTALC
M-ATT
PA2 LNA2
Uplink Mobile
Alarm Main Control Power Li-ion
Modem Indicator Unit Supply BATT
Computer with OMTData card
Wireless Modem
Power 220VAC External
OMT
OMC
Repeaters 42
-
7/30/2019 Repeater Doc
31/37
FrequencyShift Repeater
Repeaters 43
LimitationsofaConventionalRepeater
High uplink noise, especially for band-selective and wideband
repeaters
Repeater coverage is uplink limited, based on thermal noiselevel
reaching the BTS
Requires careful uplink gain setting
Difficulty in deploying high power repeaters
Minimum isolation requirements or risk of
oscillation
Requires careful choice of donor and service
antenna
Requires large tower for effective implementation
Dependent on best donor traffic conditions
Mainly suited for use in indoor coverage
Repeaters 44
-
7/30/2019 Repeater Doc
32/37
FSR vsRepeater
A conventional repeater can act as an oscillator if
the signal feedback is greater than the gain.
Isolation between donor and service antennashould be at least 10 - 15 dB more than systemgain.
Fair distance from donor antenna for properisolation; e.g. 15-20 m vertical separation and atleast 120 degree horizontal separation fornormal repeater setup for high gain operation
The FSR works on the principle that the outputsignal frequency of a channel selective repeater is
shifted from the input frequency
lower antenna isolation requirement (e.g. 70dBfor inband FSR regardless the system gain)
Fair distance from donor antenna for properisolation; e.g. 1-2 m vertical separation; lessstringent horizontal separation requirement
Isolation
Vertical
Separation
Repeater
Repeaters 45
FrequencyShiftRepeater(FSR)
The FSR is a point-to-multipoint, frequency-shifting repeater system
that overcomes antenna isolation problem in conventional repeatersystem.
Supports 2 or 4 channel frequencies.
Available in 2W, 10W or 20W.
Comprises of Master Unit (Direct or Wireless Coupling) and Remote
Unit.
Available in GSM-DCS, GSM-GSM, DCS-DCS, GSM-CDMA,
GSM-1.5GHz.
Wireless remote and local monitor function (OMT).
Optional powerful remote repeater network administration (OMC).
Repeaters 46
-
7/30/2019 Repeater Doc
33/37
SystemApplications
Point-to-Point using Direct Coupling Main Unit.
1800MHz
RU
MU
900MHz
900MHz
GSM BTS
900MHz
Repeaters 47
SystemApplications
Point-to-Point using Wireless Coupling Main Unit.
Internal or ExtAntenna Internal or Ext
Antenna
Wireless CouplingMain Unit Remote
UnitGSM Mobile
GSM BTS
Repeaters 48
-
7/30/2019 Repeater Doc
34/37
SystemApplications
Point-to-Multipoint using Direct Coupling Main Unit.
RUF1
F2MU
F2 F1
F1 F2
GSM BTS F1RU RU
F1
F1 F1
F1
F1 F1
Repeaters 49
SystemApplications
Point-to-Multipoint using Wireless Coupling Main Unit.
WC MU RU
F1 F1
F2
F1
F2F2
F1
GSM BTS RU RU
F1
F1 F1
F1
F1 F1
Repeaters 50
-
7/30/2019 Repeater Doc
35/37
Optical Repeater
Repeaters 51
SystemBlockDiagram
Repeaters 52
-
7/30/2019 Repeater Doc
36/37
MainUnitBlockDiagram
Repeaters 53
RemoteUnitBlockDiagram
Repeaters 54
-
7/30/2019 Repeater Doc
37/37
OpticalRepeaterApplications
Fiber optic coupled Repeaters are often used for In- Buildings and
also for some outdoor systems.
Airports and underground exhibition halls are some of the common
areas where fiber optic repeaters are used.
Repeaters 55
Summary
1. Introduction to Repeaters
2. Repeater Setup Considerations3. Procedure in Repeater Cell Setup
4. Repeater Block Diagrams
5. Frequency Shift Repeater
6. Optical Repeater