fsr training material_1

7/28/2019 FSR Training Material_1

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Repeater Training

(Frequency Shift Repeater)

December, 2004

Leading the Way to a Wireless Worl


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2http://www.mtico.co.kr

ContentsContents

Repeater Overview

BTS & Repeater

VFSR-C20 Overview

Pre-installation

Installation

Engineering and Optimization

Application Guideline


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RF Basic TerminologiesRF Basic Terminologies

How to minimizeHow to minimize

degradation of BTSdegradation of BTS

capacity ?capacity ?

FSR, OR, RF,FSR, OR, RF,

M/W, Laser ...M/W, Laser ...

Complex interaction influencing system - wide capacity, coverage and voicequality

Technical Consideration for Repeaters

RX DiversityRX Diversity RX SensitivityRX Sensitivity

MaximumMaximum

Output PowerOutput Power

How to monitor ?How to monitor ?

How to optimizeHow to optimize

BTS ParameterBTS Parameter

Noise FigureNoise Figure

TX SaturationTX Saturation

ReliabilityReliability


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Repeater OverviewRepeater Overview

Repeater Appearance Background

There are lots of advantages of deploying repeaters as :

Cell enhancing solution with lower cost

Many kinds of cell enhancing applications available from small room to

large coverage

Lower cost cell coverage extension solution than BTS

Traffic capacity of BTS can be highly utilized

Flexible cell coverage planning


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Example of Shadow area and Repeater Solution

Wide spaced building

(Penetration loss is large)

.

High building around BTS

Repeater

Repeater

Shadowarea

Shadow area

Shadow area


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Coverage Hole between cells

Repeater

Good Rx level Weak Ec/Io No dominant pilot Rapid fluctuation of pilot power Frequent handoff High call drop rate

=> On these areas, add repeater from Low-traffic BTS

Shrinking area


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Relocation/Cell addition neededbecause of RF signal degradationdue to new buildings or mountains

Coverage hole due to terrains

=> Use repeaters to resolve

coverage holes

Coverage Hole between cells

Repeater

Mountains

New

buildings

Repeater

Fiber Optic Cable


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Re-allocation of Traffic

load with repeaters

Optic Repeater

Hot Spot

Re-allocation of Traffic load among cells


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Re-allocation of Traffic load among sectors

mBS

Relatively high traffic(causes handoff)Relatively small

traffic

High traffic on Sector causes SoftBlocking. Sectors Traffic is relativelylow

In a HOT SPOT inside Sector, installa repeater connected to Sector

Solves Soft Blocking problem

Increases Channel Element usage

Hot Spot/In-Building Solution


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Basement

Tunnel,Underground

Feed Line(7/8")

Repeater

Building

FeedLine

(7/8")

Repeater

BTS

BTS

Isolation

Isolation

TunnelLength


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Introduction of Repeater System

The repeater system enhances the cell coverage in the radio-shadow

area where similar RF performance to the base station is required.

Classification (By the application type and Link)

- On-Frequency Repeater

- Frequency Shifting Repeater : Use unoccupied FA as Link Channel

- Microwave Repeater : Use Microwave Frequency

- Fiber Optic Repeater

- Small Repeater for in-Building

BTS RepeaterMobileStation

Donor Cell

Pick upAntenna

Service

Antenna


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On-Frequency Repeater

Merits

- Use same TX/RX Frequency

- Multi FA is available

Demerits

- Repeater output power is limited

- High antenna Isolation between RX/TX Antenna is required.

- High gain, Low side/back lobe antenna is required

- Difficult installation of antennas ( Accurate direction setting is required)

Base StationRepeater

Mobile

Station

Donor Cell

Pick upAntenna

ServiceAntenna

F1

F1


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Frequency Shifting Repeater

Merits

- Utilize unoccupied FA as Link FA

- High antenna isolation between a link antenna and a service antenna is not required

Demerits

- limited Service FA.

- Likely to degrade performance of a BTS due to using adjacent FA

BaseStation

Base Station Donor

MobileStation

Donor Cell

Link

Antenna

F1

F1

Repeater

LinkAntenna Service

Antenna

F2


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Microwave Repeater

Merits

- Use Microwave Link between a Donor unit and a Remote unit

- Multi FA is available

Demerits

- Line-of-sight between DU and RU is required

- Accurate antenna tilting is necessary

- Susceptible to radio environment

BaseStation

Base Station Donor

Mobile

Station

Donor Cell

M/W LinkAntenna

servicefrequency

F1

Repeater

ServiceAntenna

Microwave

Link

M/W Link

Antenna


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Fiber Optic Repeater

The fiber optic cable links a Donor unit to a Remote unit. A single fiber may

be used to interconnect the units using WDM(Wavelength Division Multiplex).

Merits

- No Limits of FAs

- Long link distance

- Independent of Air interface : Not degrade the BTS performance

- High reliability which has excellent electrical characteristics.

Demerits

- High rental cost by using optical fiber

- Time delay for CDMA

BaseStation

Base Station

MobileStation

Donor Cell

F1

F1

OpticRepeater

ServiceAntenna


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Small sized & Low output powered Repeater

Applicable to the service inside a building

Limited output power

REM.

BASE

STATION

[Application of a small sized & low output powered repeater]


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DONOR

BASE

STATION

REMOTE

OPT

ICC

ABLE

Undergroung

[Application of small sized & low output powered Repeater (Optical Link)]

Small sized & Low output powered Repeater


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BTS & RepeaterBTS & Repeater

Optic Cableor RF Link

BTS

Rx sensitivitytest

Rx sensitivitytest

Repeater

Cell coverage and capacity degradation by RX sensitivity degradation due to improperrepeater installment

BTS Rx Sensitivity degradation by reverse link of repeater


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Noise level rise of unoccupied WalshCode by amplitude nonlinearity

IMD on Frequency Domain and Code Domain



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PilotPaging

Synch

BB

R R R R

B B B

R : traffic Ch through repeaterB : traffic Ch through BTS

5dB

Trafficcapacity

BTS HPAmax ouput

Repeater HPAmax output

BTS / Repeater HPA level

Maxcapacity

BTSHP

Aoutput

RepeaterHP

Aoutput

BTS

Repeater

BTS forward

capacity degration

BTS / Repeater HPA level

BTS HPA

max ouput

Repeater HPA

max output

Traffic

capacity

Max

capacity

Ec/Io degradation by Forward Link saturation causes severe forward link capacitydegradation.

Lower Ec/Io mobile requires more forward traffic CH power by Forward Power Control.

BTS connected with a repeater in urban area is easy to be saturated and to be degradedin forward link capacity.

Forward Link capacity degradation by Repeater


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Mobiles for each FA => Hash free mobiles => One mobile for all FAs Inaccuracy of measurement by traffic => Compensation by considering traffic loading factor Automatic measurement of Main TX/RX, Diversity and M+D path Manual FA setting

Rx sensitivity & diversity gain measurement with CLM


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What is FSR?

VFSR-C20 OverviewVFSR-C20 Overview

First donor near the BTS receives signal and converts it into unavailable

signal and transports to remote. Then the remote receives signal and converts

it into original frequency, and service after amplifying

Purpose

- Traffic dispersion in dense urban areas

- Cover the shadowed area/Small-size area

- Seamless Service provided in rural areas or on highways


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Antenna IsolationI = SG + PL + LGWhere:I = Antenna Isolation in dB.SG = Service Antenna Gain, in the direction of the Link Antenna (vertical gain)LG = Link Antenna Gain, in the direction of the Service Antenna (vertical gain)PL = Path Loss, i.e., the amount of attenuation due to the distance between the antennas.

For example, FSR needs a minimum isolation value of at least 70dB.Rearrange the equation to compute for path loss : PL = I - SG - LG

Question)

1) Service Antenna : BXA-80040/8CF (Amphenol Actel, Inc.)Gain : 20dBi, Electrical Down tilt : 0,Side lobe Suppression at 90 : -26dB

2) Link Antenna : HTPS-08-18/1.2 (Xi'an Haitian Antenna Tech)Gain : 18dBi

Side lobe Suppression at 270 : -28dB

Pathloss ?


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Answer)Accordingly, the isolation can be calculated as follows :

I = -70dB Required IsolationSG = -6dB Service Antenna Gain [20dBi gain. 26dB side lobe suppression]LG = -10dB Link Antenna Gain [18dBi gain . 28dB side lobe suppression]

Next we insert the above numbers into our formula and calculate the path loss required:PL = -70 - (-6) - (-10) = -54dB of Path Loss

Distance :For 850Hz Cellular band: 1 meter of separation = 31dB of lossEach doubling of the distance thereafter adds an additional 6dB of loss.Therefore, the Cellular Band repeater in our example would need more than 16 meters of antennaseparation:

1 meter = 31dB2 meters = 6dB (37dB)4 meters = 6dB (43dB)8 meters = 6dB (49dB)16 meters = 6dB (55dB)

-----------------------------------Total = 55dB of path loss

Note that this is only an estimate. The isolation value will vary based on tower type, system

configuration, nearby obstructions, and wind loading of the tower.


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Connect a signal source to the service antenna cable and inject a CW signal.Connect a spectrum analyzer to the link antenna cable.Measure the power level of the injected signal with the spectrum analyzer.Check the difference between the injected power level and the received signal strength.

For example,A signal source to the service antenna = +10dBmInjected signal with the spectrum analyzer = -70dBmAntenna Isolation : +10dBm - (-70dBm) = 80dB.

Antenna Isolation Test

Output Level: 10dBm

Received Level: -70dBm

Isolation : 10-(-70)=80dB

Isolation(dB)= S/G S/A

Gain(Repeater)Isolation 15dB



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Main Features Input overload protection in DU

- If DU forward input level is over +20dBm, DU will shutdown automatically- If DU reverse input level is over -30dBm, DU will shut down automatically

Auto Shutdown for Output power

- When Over Power Alarm occurs, shutdown & retrial of enabling is repeated five times

RX Diversity

- Time Diversity method is adapted in the FSR system

Interface with Duplex type and Simplex type of BTS

- Input and output of Donor Unit is fit for interface with either duplex type or simplex

type BTS

External Alarm port

- the FSR provides an external alarm port to support interface of four alarms

ALC for FWD Output power

- Optimum forward RF output level for the DU is approximately +33dBm(+37dBm max)

ALC for REV Output power

- Optimum reverse RF output level for the RU is approximately +32dBm (+35dBm Max)


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Mechanical Description


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Module of the Donor Unit


1. PSU (Power Supply Unit)

Input :- 48VDC 20% Low limit shutdown

High limit shutdown

Electrical Power cable connection status indicator

(Green LED)

Output : +27V/4A, +8V/6A

2. FWD UDC (FWD Up Down Converter)

Fwd SVC freq. converts to Fwd link freq.

Inputted forward service freq. converts to IF Freq.

IF Freq. is 160MHz

Consists of Down Conversion circuitry, SAW Filter, Up

Conversion circuitry, Local oscillator.


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Module of the Donor Unit

7. FEU (Front End Unit)

Consists of a BTS duplexer, a simplexer BPF, a REV LNA

and a FEU connector board.

REV LNA which amplifies and detects reverse link signal.

8. DPX (LinkDuPleXer)

DPX consists of a link duplexer which filters forward

link output signal and reverse link input signal, an

Arrestor.


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VFSR C20 O iVFSR C20 O i


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Module of the Remote Unit


1. PSU (Power Supply Unit)

Input :- 48VDC 20% Low limit shutdown

High limit shutdown

Electrical Power cable connection status

indicator (Green LED)

Output : +27V/13A, +8V/8A

2. FWD UDC (Fwd Up Down Converter)

Fwd link freq. converts to Fwd SVC freq.

Inputted forward service freq. converts to IF Freq.

IF Freq. is 160MHz

Consists of Down Conversion circuitry, SAW Filter, Up Conversion

circuitry, Local oscillator.


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VFSR C20 O iVFSR C20 Overview


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Module of the Remote Unit

5. FWD HPA (FWD High PowerAmplifier)

Maximum output power is 44.5dBm (About 28W)

Input voltage is 27VDC.

Gain is 50dB

FWD HPA has alarm for high temperature and VSWR.

6. REV HPA (REV High PowerAmplifier)

Maximum output power is 37dBm (8W)

Input voltage is 27VDC.

Gain is 50dB

FWD HPA has alarm for high temperature and VSWR.


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VFSR C20 OverviewVFSR C20 Overview

FSR - Reverse Gain Budget of DU


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Donor Unit _ RF Specifications


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Remote Unit _ RF Specifications (Cont.)


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Frequency Allocation



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Frequency Allocation (Cont.)


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Donor Unit _ Commissioning Test



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Remote Unit _ Commissioning Test



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IS-95A/B Standard

Pre-InstallationPre-Installation


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Site Selection

Easily installed antenna with proper height Less interference from other BTS Cells Easy access and maintenance of the equipmentAvoiding direct sunlight to protect equipment

Easy access to electrical powerA dry and cool environment



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Check List for Donor Unit

Check physical damage on the packing box and the Unit

DC input cable

Ground wire with terminal lug

RS-232 serial cable

Screw M6, M8

RF cable connection

Directional Coupler (connection, rated power, coupling value)

Electrical Power (-48Vdc)



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Check List for Remote Unit Check physical damage on the packing box and the Unit

DC input cable

Ground wire with terminal lug

RS-232 serial cable

Screw M6, M8

Door lock key

Antenna port cable connection

Service Antenna installation, Antenna Type, Antenna Direction Service Antenna VSWR / DTF(Distance To Fail)

Power Divider status

(Connection, rated power,number of divide and divide rate)

Electrical Power (-48Vdc)

InstallationInstallation


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Installation procedure overview

() varies with environmental conditions

DU forward input level check

> +20dBm?

Coupler, Cable & Connection Check

Not OKOK

Start

End

Set DU FWD path gain. Input : +11dBm1dB. Output : +33dBm1dB

Set RU FWD path gain setting

Reverse path gain optimization

Set DU REV path gain (Min.)

Set RU REV path gain setting (100 ~ 110dB)



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Forward Path Output Power Setting

Input Power MeasurementOf the Donor Unit

+11dBm1dB/Total?

- Coupling Port Check

- Connection Check

Not OKOK

Start

Output Power Adjust by

NMS FWD attenuation [dBm] Measurementof the Coupling Port

Output Power Measurement

+33dBm1dB/Total?

Not OK

- RF Cable Check- Connection Check

Output Power MeasurementOf the Remote Unit

+40dBm/Total?

End

Not OK

OK

- RF Cable / Connection Check- NMS Normal Operating Status Check

- RG Cable / Connection Check- NMS Normal Operating Status Check

Donor Site

Remote Site

OK


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Remote Unit Output Power Measurement

- Target RU output power : +40dBm

1dB/Total- Coupling Port : 30dB

- RU Coupler output : +10dBm1dB/Total

Remote Unit Output Power Setting

- Determine output power according to radio environment and numbers of operating FA.- Check the final output power on the Operating Software if it is the target output power

and compare it with that measured at the coupling port.

Forward Path Output Power Setting Remote Unit



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Reverse Path Gain Setting (Example : Not Use CLM)

-75dBm Injection at Rx Input Port

Output Power ?

- Directional Coupler Check- Connection Check

Not OK

Start

Output Power Measurementof the Donor Unit Input Level

Not OK

Output Power Measurementof the Donor Unit Input Level

Reverse Gain?

End

OK

- Reverse Gain Adjust

Donor Site

Remote Site

OK



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-75dBm Injection at Rx Input Port (Remote Site)

- Signal Generator Setting : -75dBm/CW

- Input Port (Filter) : REV Main / REV Div

Output Power Measurement of the Donor Unit Input Level (Donor Site)

- Checks reverse path output power of the reverse main and diversity.

- Reverse Gain : Donor Output Level (Main / Diversity) - Remote Input Level (-75dBm)

Output Power Measurement of the Donor Module Input Level (Donor Site)

- Real reverse gain connecting BTS : BTS coupler output - Remote Input Level (-75dBm)

Reverse Path Gain Setting (Example : Not Use CLM)



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Reverse Path Gain Optimization (Example : Not Use CLM)

Noise Floor Measurement at Output ofREV path(RU)

Noise FloorDegradation xdB ?

- Reverse Gain Adjustment

Not OK

Start

Connecting Repeater, Noise FloorMeasurement at Reverse Output(DU)

End

OK

Donor Site

Engineering & OptimizationEngineering & Optimization


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Repeater Delay Calculation

Delay Calculation

- CDMA Bandwidth : 1.2288MHz(1.2288Mcps)

- Time per 1Chip(t) = 1 F = 1 1.23Mcps = 0.814- Electromagnetic wave velocity(c) = 3 10 m/s

- Propagation distance per 1Chip(s) = t c =244.2m

- Distance of between RU and H/O area(L1) => Delay Chip = L1 c

- Distance of between BTS and H/O area(L2) => Delay Chip = L2 c

Air Delay

- Delay Chip per 1Km = d t = 3.33 0.814 = 4.091Chips

Repeater Delay

- Repeater Delay Spec(e) : 5

- Delay Chips = e t = 5 0.814 = 6.1425Chips

8


Parameter Setting Criteria


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Parameter Setting Criteria

Parameter concerning call setup

Parameter setting criterion according to path

At call setup, search window size of BTS searching MSaccess probe

Classification

PAM_WIN_L

Parameter

PAM_WIN_L : Preamble_Window_Length

SRCH_WIN_A_LSRCH_WIN_N_L

H/O of between OR and neighbor BTS

Forward Path

SRCH_WIN_A_LH/O of between OR and BTS

Signal Tracking at same PNReverse Path

Classification

DEMODE_ WIN _L

Parameter

SRCH_WIN_A_L : Search_Window_Active Length

DEMODE_WIN_L : Demodulation_Window_Length

Basic Concept of CDMA Air parameter window



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Available regionfor all mobiles

possible or impossible,

depends on MIN

Impossible region forall mobiles,even

Rx level is enough

BTS

A : 2 Km (8.2 chips)

B : 4 Km (16.4 chips)

SRCH_WIN_A8.2 chips

Active Window parameter

Reverse Cell coverage by Access Ch parameter windowsize

18.4 chips

PN1

PN2

20.1 chips

PN2

PN1

PN 1 PN 2

0.1km (0.4 chips)

5km (20.5 chips)

5.5km(22.5 chips)

1km (4.1 chips)

Neighbor Window parameter for Handoff

Wherever I am, time differencebetween PN2 and PN1 is less than 21chips !! So SRCH_WIN_N should beover 21 chips !!

1.2288Mcps, 0.814usec/chip Propagation delay : 3.3usec/Km, 4chip/Km Window parameter : Active, Neighbor,

Remaining, Demodulation, Access window

Access Probe intentional delay : RN, RS, PD.

Basic Concept of CDMA Air parameter window



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BTS for low traffic and frequent H/O

Repeater Engineering Criterion by BTS

After

u-Cell

BSC

FSR

T1/E1

Before

Omni

BSC

T1/E1



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BTS of large number of FA with low traffic loading

( suburban area, satellite city and middle sized city)

Before After

BSC

T1/E1

BSC

FSR FSR

T1/E1

u-Cell u-Cell




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Large sized building

Before After

Shadowed Area

FSR

Large sized building

u-Cell

ANT


Application GuidelineApplication Guideline


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Field Verification after Repeater Installation (Sample)

Conducted inside Coverage

. Small repeater : 6call /FA (1Call for Call Test)

. Standard repeater : 11call /FA (1Call for Call Test)

. Performance should be no less than 5% lower than that in unloaded condition.

CapacityTest

Call origination / termination : Area where 90% of 40 consecutive M to M calls are

successful is considered good

Call Drop : Area with less than 5% is considered good

Exception :If input power to donor antenna of repeater is very low, performancewith 5% lower than expected is considered acceptable.

Call Test

Target : Coverage extension

. Rx Level with no traffic : above -85dBm

. Ec/Io with no traffic : above -8dB

. Forward FER : less than 1 %

Coverageverification

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