Fresh Field Mtc 007 Section 1

8/9/2019 Fresh Field Mtc 007 Section 1

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Advanced RadioPlanning &

OptimisationSection One

Techniques


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2001 Freshfield Communications Limited.Company Confidential Slide 2

Evolution of GSM NetworksEvolution of GSM Networks SFH and Frequency Hopping BasicsSFH and Frequency Hopping Basics

SummarySummary

Presentation OutlinePresentation Outline


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At the end of this course, attendees will:At the end of this course, attendees will: Have an appreciation of the evolution of GSM networksHave an appreciation of the evolution of GSM networks

Understand basics of slow frequency hoppingUnderstand basics of slow frequency hopping

In future modules, learn about selfIn future modules, learn about self--regulating networks andregulating networks and

examine a practical case studyexamine a practical case study

ObjectivesObjectives


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Evolution of GSM Networks 1989 2001Evolution of GSM Networks 1989 2001

PredictionsPredictions

CoverageCoverage

Cell ClassificationCell Classification

LayeringLayering

Handover AlgorithmHandover Algorithm

BCCH AssignmentsBCCH Assignments

TCH AssignmentsTCH Assignments

BSS DatafillBSS Datafill

Frequency AssignmentFrequency Assignment

HoppingHopping

Hopping AssignmentHopping Assignment

Macrocell AssignmentsMacrocell Assignments

IntegrationIntegration

Power ControlPower ControlVAD / DTXVAD / DTX

Neighbour List GenerationNeighbour List Generation

Speech / Channel CodecSpeech / Channel Codec

C/I Delta MatricesC/I Delta Matrices

HataHata--OkumuraOkumura

Mobile HandportableMobile Handportable

MacrocellMacrocell

Single LayerSingle Layer

SimpleSimple

MRPMRP

MRPMRP

ManualManual

DUMB AFPDUMB AFP

NoneNone

CyclicCyclic

Band SegmentationBand Segmentation

NoneNone

Uplink OnlyUplink OnlyOffOff

ManualManual

FRFR

Derived from Predictions (pixelDerived from Predictions (pixel

by pixel)by pixel)

Automatic MultiAutomatic Multi--Variant OptimisedVariant Optimised

Ubiquitous CoverageUbiquitous Coverage -- PCNPCN

Hierarchical MacroHierarchical Macro -- MicroMicro -- PicoPico

MultiMulti--layerlayer

IntelligentIntelligent

MRPMRP

Super ReSuper Re--use, IUO, 1/1 and 1/3 Fractional Reuse, IUO, 1/1 and 1/3 Fractional Re--useuse

AutomaticAutomatic

SMART AFPSMART AFP

A Must For All NetworksA Must For All Networks

Automatic Intelligent AssignmentsAutomatic Intelligent Assignments -- HSN, MAIO,HSN, MAIO,

SeamlessSeamless -- Steal Carriers for MicrocellsSteal Carriers for Microcells

TotalTotal

Uplink and DownlinkUplink and DownlinkOnOn

Automatic in Planning / Network EnvironmentAutomatic in Planning / Network Environment

FR / HR / EFR and AMRFR / HR / EFR and AMR

Derived from Optimised Predictions,Derived from Optimised Predictions,

Supplemented with Measurement data fromSupplemented with Measurement data from

engineering test mobilesengineering test mobiles


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New site integration must be seamless:New site integration must be seamless: Faster site integration means higher traffic takeFaster site integration means higher traffic take--up and thereforeup and therefore

higher revenuehigher revenue

New sites need not be on a grid for interference reductionNew sites need not be on a grid for interference reduction

Frequency planning should take into account:Frequency planning should take into account: Cell carried traffic reported as a weekly average basisCell carried traffic reported as a weekly average basis

Inter Inter--cell handover attempts reported as a weekly averagecell handover attempts reported as a weekly average

NetworkNetwork--based drivebased drive--test data and Atest data and A--bis data collected from allbis data collected from all

subscribers for C/I delta matrix creationsubscribers for C/I delta matrix creation In a fractional reuse network, a clean BCCH:BSIC plan and a wellIn a fractional reuse network, a clean BCCH:BSIC plan and a well--

managed TCH MAmanaged TCH MA--List:HSN:MAIO planList:HSN:MAIO plan

Todays NetworksTodays Networks


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SFH and Fractional Reuse BasicsSFH and Fractional Reuse Basics

Traditional Capacity SolutionsTraditional Capacity Solutions Cell SplittingCell Splitting Additional cells can be placed in hotAdditional cells can be placed in hot--spot locations. However, this requiresspot locations. However, this requires

additional site realadditional site real--estate outlay, but is required at startestate outlay, but is required at start--up to fulfil capacityup to fulfil capacity

and interference requirements.and interference requirements.

Add TransceiversAdd Transceivers Additional TRXs can be added to existing sites and this is a cheaperAdditional TRXs can be added to existing sites and this is a cheapersolution compared to cell splitting. However, it still requires TRX outlay,solution compared to cell splitting. However, it still requires TRX outlay,

and additional E1/T1s as necessary.and additional E1/T1s as necessary.

Microcellular DeploymentMicrocellular Deployment

Lower Lower--cost microcells can be deployed at traffic hot spots. However, thiscost microcells can be deployed at traffic hot spots. However, this

still requires additional T1s and microcell site realstill requires additional T1s and microcell site real--estate outlay.estate outlay.


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2001 Freshfield Communications Limited.

Company Confidential Slide 7


Todays Novel Capacity SolutionsTodays Novel Capacity Solutions Fractional Reuse PatternsFractional Reuse Patterns BCCH carriers are planned using traditional 4/12 reuse patterns and TCHsBCCH carriers are planned using traditional 4/12 reuse patterns and TCHs

are planned using 1/3 or 1/1 reuse patterns. Additional cost is theare planned using 1/3 or 1/1 reuse patterns. Additional cost is the

deployment of hybrid combiners in FH sections of network.deployment of hybrid combiners in FH sections of network.

Multiple Reuse PatternsMultiple Reuse Patterns

Different TRXs are planned using different frequency bands and reuseDifferent TRXs are planned using different frequency bands and reuse

patterns; for example, TRX1 may be planned using 4/12, TRX2 may bepatterns; for example, TRX1 may be planned using 4/12, TRX2 may be

planned using 3/9.planned using 3/9.

Hybrid MRP/FRP: TRX1 or BCCH may be planned using 4/12, TRX2 may beHybrid MRP/FRP: TRX1 or BCCH may be planned using 4/12, TRX2 may be

planned using 3/9 and TRX3 may be planned using 1x3 FRP.planned using 3/9 and TRX3 may be planned using 1x3 FRP.


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Company Confidential

Slide 8


Todays Novel Capacity SolutionsTodays Novel Capacity Solutions Intelligent OverlayIntelligent Overlay--UnderlayUnderlay Planning is similar to MRP and hybrid MRPPlanning is similar to MRP and hybrid MRP--FRP; additional interferenceFRP; additional interference

advantage arises because BSC dynamically calculates C/I and assigns aadvantage arises because BSC dynamically calculates C/I and assigns a

supersuper--reuse channel for low C/I and a regular reuse channel for high C/I.reuse channel for low C/I and a regular reuse channel for high C/I.

Multi Multi--band Planningband Planning

If 900MHz and 1800MHz spectrum are available, 1800 MHz sites can beIf 900MHz and 1800MHz spectrum are available, 1800 MHz sites can be

used to provide hotused to provide hot--spot traffic solutions; 900 MHz sites are used tospot traffic solutions; 900 MHz sites are used to

guarantee coverage.guarantee coverage.


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Slide 9


General Advantages of Novel SolutionsGeneral Advantages of Novel Solutions Optimise InvestmentOptimise Investment Add TRXs without new BTS sites or modify configuration without TRXAdd TRXs without new BTS sites or modify configuration without TRX

introductionintroduction

Increase Capacity or Improve QualityIncrease Capacity or Improve Quality Harness spectrum efficiencyHarness spectrum efficiency

Enhance engineering flexibilityEnhance engineering flexibility

Configurations can be tailored to traffic requirements in high load and lowConfigurations can be tailored to traffic requirements in high load and low

load areas without effecting significant network infrastructure changesload areas without effecting significant network infrastructure changes


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Slide 10


Novel Solutions Require:Novel Solutions Require: Slow Frequency HoppingSlow Frequency Hopping Frequency diversityFrequency diversity

Interferer diversityInterferer diversity

Interleaving benefitsInterleaving benefits

Dynamic Power ControlDynamic Power Control Uplink and/or downlink reduced interference through reducedUplink and/or downlink reduced interference through reduced

transmission power. Subscribers close to the serving base station maytransmission power. Subscribers close to the serving base station may

have C/I as high as 25 dB when only 12have C/I as high as 25 dB when only 12--14 dB is sufficient to maintain good14 dB is sufficient to maintain good

speech quality. By permitting reduction in power, tighter reuse schemesspeech quality. By permitting reduction in power, tighter reuse schemes

can be employed, resulting in higher capacity.can be employed, resulting in higher capacity.

Discontinuous Transmission (DTX)Discontinuous Transmission (DTX)

Uplink and/or downlink reduced interference through reducedUplink and/or downlink reduced interference through reduced

transmission burststransmission bursts


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Slide 11

TRX1 CONTROLLER transmitter

f0...fn hybrid

combiner

TRX2 CONTROLLER transmitterf0...fn hybrid

combiner

TRX3 CONTROLLER transmitter

f0...fn hybrid

combinerTRX4 CONTROLLER transmitter

f0...fn

Synthesiser HoppingSynthesiser Hopping


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Slide 12

ARFCN AllocationMobile Allocation (MA)Mobile Allocation (MA)

Starting ARFCNMobile Allocation Indication Offset (MAIO)Mobile Allocation Indication Offset (MAIO)

Hopping Sequence Number (HSN)Hopping Sequence Number (HSN)

0 Cyclic

1-63 Pseudo Random

Frequency Hopping ParametersFrequency Hopping Parameters


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Slide 13

Allocated frequency spectrum is divided into:Allocated frequency spectrum is divided into:

BCCH frequenciesBCCH frequencies

TCH FrequenciesTCH Frequencies

A1

A2A3

A1A2

A1

A3

1x3 TCH Planning1x3 TCH Planning

Fractional Reuse PlanningFractional Reuse Planning

A1, A2 and A3 representfrequency groups

Frequencies A1/A2/A3 are reused over every site.

With 4 frequencies, 25% fractional load obtained:

25% burst interfered with and 75% bursts-interference free


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Slide 14


Fractional Reuse PlanningFractional Reuse Planning Only possible with synthesiser hoppingOnly possible with synthesiser hopping

Requires hybrid combiner deployment in FH part of network withRequires hybrid combiner deployment in FH part of network with

consequent higher insertion loss!consequent higher insertion loss!

Repeaters and enhancers must be wideRepeaters and enhancers must be wide--band!band!

Fractional loading: With 12 TCH carriers, 1/3 offers 4 carriers perFractional loading: With 12 TCH carriers, 1/3 offers 4 carriers per

TRX per cell. 1/1offers 12 carriers per cell. With S222TRX per cell. 1/1offers 12 carriers per cell. With S222

configuration, 1/3 offers 25% fractional load compared with 8%configuration, 1/3 offers 25% fractional load compared with 8%

fractional load from 1/1.fractional load from 1/1.

Practically, with high fractional load, 1/3 may perform worse thanPractically, with high fractional load, 1/3 may perform worse than

1/1 in areas where it is difficult to control interference from co1/1 in areas where it is difficult to control interference from co--

channel groups. This occurs, for example, in the motorway areas,channel groups. This occurs, for example, in the motorway areas,

and is particularly notorious when the sectors are focused onand is particularly notorious when the sectors are focused on

each other.each other.


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Slide 15


Where sectors are directly focused on

one another, and particularly in hilly areas,

1/3 with high fractional load is subject to more

interference than 1/1.

High interference with 1/3High interference with 1/3

can also occur in areascan also occur in areas

where the sector antennaewhere the sector antennae

azimuth are very differentazimuth are very different


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Slide 16

Fractional ReuseFractional Reuse

Example:Example:

Assuming 5 MHz of spectrum and allowing for a 200 kHzAssuming 5 MHz of spectrum and allowing for a 200 kHz

guard band, a total of 24 carriers will be available. Theseguard band, a total of 24 carriers will be available. These

can be split as follows:can be split as follows:

BCCHBCCH--12 carriers12 carriers

TCH TCH--12 Carriers12 Carriers

The BCCH can be planned on 4/12 yielding 1 BCCH carrierThe BCCH can be planned on 4/12 yielding 1 BCCH carrier

in each sector in the cluster.in each sector in the cluster.

The TCH are planned on 1/3 giving a maximum of 4 TRX sThe TCH are planned on 1/3 giving a maximum of 4 TRX sper sector. The loading on each sector can be varied fromper sector. The loading on each sector can be varied from

1TRX (25%) to 3 TRXs (75%).1TRX (25%) to 3 TRXs (75%).


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Slide 17

Fractional LoadingFractional Loading

Fractional load can be varied to offer capacityFractional load can be varied to offer capacity--quality tradequality trade--off:off:

For example, assuming 5MHz of spectrum, and allowing for a 200For example, assuming 5MHz of spectrum, and allowing for a 200

kHz guard band, a total of 24 carriers will be available.kHz guard band, a total of 24 carriers will be available.


Traditional clusterTraditional cluster4/124/12

S222S222

1/3 cluster for TCH, load = 25%,

S222, 0% capacity increase

1/3 cluster for TCH, load = 50%, S333,

65% capacity increase


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Slide 18


Practical Deployment of Fractional Reuse:Practical Deployment of Fractional Reuse:

Requires a clean BCCH and BSIC plans obtained from anRequires a clean BCCH and BSIC plans obtained from an

automatic resource planning tool, based upon accurate urbanautomatic resource planning tool, based upon accurate urban

prediction and driveprediction and drive--test data.test data.

1/3 or 1/1 deployment: In networks with small frequency1/3 or 1/1 deployment: In networks with small frequency

spectrum allocation (5 MHz), 1/1 offers better interference controlspectrum allocation (5 MHz), 1/1 offers better interference controland higher capacity than 1/3, since 1/3 will have high fractionaland higher capacity than 1/3, since 1/3 will have high fractional

load. In networks with large frequency spectrum allocation (10load. In networks with large frequency spectrum allocation (10--1515

MHz), the use of 1/3 will result in improved voice quality.MHz), the use of 1/3 will result in improved voice quality.

Randomised HSNs (1Randomised HSNs (1--63), avoiding the use of 0 (cyclic).63), avoiding the use of 0 (cyclic).


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Slide 19


Practical Deployment of Fractional Reuse:Practical Deployment of Fractional Reuse:

MAMA--List Planning: Some vendors (e.g. Nokia) permit fixed MAList Planning: Some vendors (e.g. Nokia) permit fixed MA--

Lists per cell but with MAIO management; other vendors (e.g.Lists per cell but with MAIO management; other vendors (e.g.

Ericsson) permit different channel groups and therefore differentEricsson) permit different channel groups and therefore different

MAMA--Lists for different TRXs per cell, but with restrained MAIOLists for different TRXs per cell, but with restrained MAIO

management. Operators may choose the following:management. Operators may choose the following: Network Network--wide Fixed MAwide Fixed MA--Lists per cellLists per cell

Staggered MAStaggered MA--List per cell to improve interference performance whilstList per cell to improve interference performance whilst

maintaining low fractional loadmaintaining low fractional load

Unique MAUnique MA--Lists per TRXLists per TRX


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Slide 20


Network Network--Wide Fixed MAWide Fixed MA--List Concept (12 carrier example)List Concept (12 carrier example)

Advantages

Database management is easier (only one

list is required for 1/1 or only three lists

are required for 1/3)

No planning is required for TCHs

Works well in near-regular cell layouts

Disadvantages

Makes no distinction between high traffic

and low traffic cells. Therefore no added

protection for high traffic cells.

If more than S222 configuration, MAIOmanagement is required.

F1F1--F12F12

F1F1--F12F12 F1F1--F12F12F1F1--F12F12

F1F1--F12F12 F1F1--F12F12


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Slide 21


Staggered MAStaggered MA--List Concept (12 carrier example)List Concept (12 carrier example)

Advantages

MA-List is optimised depending upon

carried traffic or interfered area

Improved voice quality

Only small reduction in supportedcapacity

Disadvantages

Requires AFP program to support MA-List

planning

Must have a database which maintainsMA-Lists for different TRXs

F1F1--F10F10

F3F3--F12F12 F2F2--F11F11F1F1--F10F10

F3F3--F12F12 F2F2--F11F11


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Slide 22


Unique MAUnique MA--List Per TRX Concept (12 carrier example)List Per TRX Concept (12 carrier example)

Advantages

No planning required for TCH

If the bands F1-F5 and F6-F12 are very far

apart e.g. 20 MHz, then this option is

necessary anyway

Disadvantages

Reduced trunking efficiency

Higher fractional load resulting in higherinterference

TRX2: F6TRX2: F6--F12F12

TRX1: F1TRX1: F1--F5F5TRX1: F1TRX1: F1--F5F5

TRX1:F

1TRX1:F

1--F5F5

TRX1:F

1TRX1:F

1--F5F5



TRX2: F6TRX2: F6--F12F12 TRX2: F6TRX2: F6--F12F12


TRX2: F6TRX2: F6--F12F12TRX2: F6TRX2: F6--F12F12


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Slide 23


MAIO ManagementMAIO Management

If a fixed or staggered MAIf a fixed or staggered MA--list is used, then MAIO management islist is used, then MAIO management is

required. At a minimum, each TRX must be offset from therequired. At a minimum, each TRX must be offset from the

adjacent TRX by 2, thus preventing adjacent channeladjacent TRX by 2, thus preventing adjacent channel

interference. If a unique MAinterference. If a unique MA--list is used for each TRX, then MAIOlist is used for each TRX, then MAIO

management may not be necessary provided the MAmanagement may not be necessary provided the MA--lists arelists areindeed unique.indeed unique.

DL Power Control StrategyDL Power Control Strategy

DL power control adjustments will be RXQUAL driven only,DL power control adjustments will be RXQUAL driven only,

guaranteeing similar C/I performance within the cell areaguaranteeing similar C/I performance within the cell area


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Slide 24


Channel Assignment PriorityChannel Assignment Priority

Channel Allocation Profile: With a clean BCCH plan, the BCCHChannel Allocation Profile: With a clean BCCH plan, the BCCH

carrier should be given assignment priority over TCH channelscarrier should be given assignment priority over TCH channels

for better FER performance.for better FER performance.


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Slide 25

Optimisation of a frequencyOptimisation of a frequency--hopped networkhopped network

Key Optimisation Parameters:Key Optimisation Parameters:

Channel Allocation ProfileChannel Allocation Profile: Since the BCCH plan, if created using: Since the BCCH plan, if created using

an advanced AFP tool, will offer better C/I, the channel allocationan advanced AFP tool, will offer better C/I, the channel allocation

profile should be set as:profile should be set as:

BCCH allocation priorityBCCH allocation priority

BCCH timeBCCH time--slot fillingslot filling TCH random slot allocation (no controlled TCH filling)TCH random slot allocation (no controlled TCH filling)

Border Area ControlBorder Area Control: If 1/1 or 1/3 is deployed over an area,: If 1/1 or 1/3 is deployed over an area,

special consideration must be given to the border with thespecial consideration must be given to the border with the

traditional cluster. Expect 1/3 sites to suffer higher interferencetraditional cluster. Expect 1/3 sites to suffer higher interference

from 1/1 sites if they share the same band, because of the higherfrom 1/1 sites if they share the same band, because of the higherfractional load with 1/3.fractional load with 1/3.

FER and not RXQUALFER and not RXQUAL: RXQUAL is very pessimistic in frequency: RXQUAL is very pessimistic in frequency--

hopped networks. Drivehopped networks. Drive--testing should be based upon FER.testing should be based upon FER.


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Slide 26

Optimisation of a frequencyOptimisation of a frequency--hopped networkhopped network

Key Optimisation Parameters:Key Optimisation Parameters:

Power Control SamplesPower Control Samples: The number of samples used for: The number of samples used for

estimating RXLEV and RXQUAL will depend upon location: Inestimating RXLEV and RXQUAL will depend upon location: In

motorway areas, with fast moving mobiles, select few samples. Inmotorway areas, with fast moving mobiles, select few samples. In

urban areas with slower moving traffic select more samples.urban areas with slower moving traffic select more samples.

Downlink Quality TriggerDownlink Quality Trigger: Typically RXQual 4: Typically RXQual 4--5.5. Handover ParametersHandover Parameters:: Handover RXLEV sample filter andHandover RXLEV sample filter and

ramping lengths.ramping lengths.


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Slide 27

SummarySummary

GSM networks have evolved considerably over the last 11GSM networks have evolved considerably over the last 11

years.years.

Several techniques are now available for icreasingSeveral techniques are now available for icreasing

network capacitynetwork capacity

Fractional Reuse is now a very common techniqueFractional Reuse is now a very common technique Implementation of fractional reuse requires the adoptionImplementation of fractional reuse requires the adoption

of interference reducing methodsof interference reducing methods

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Fresh Field Mtc 007 Section 1

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