03%2E Key UMTS Radio Design Strategy 26 Considerations

5/27/2018 03%2E Key UMTS Radio Design Strategy 26 Considerations

1/51NORTEL NETWORKS CONFIDENTIAL Version 3.1

Key UMTS Radio Design Strategy &

Considerations


2/51Presentation Name - 1NORTEL NETWORKS CONFIDENTIAL

Content

1. 3G and 2G Design Similarities2. 3G and 2G Design Differences

3. CDMA Myths and Misconceptions

4. Design Considerations



Sample GSM Link Budget

Basic link budget

concept the same

Some parameters such

as shadowing, in-

building penetration,

and body loss are

independent of cellulartechnology

GSM900 GSM1800

PA Max Output 44.8 44.8

Rx Sensitivity -110 -110

Rx Sensitivity + Diversity -115 -115

Common Cable Losses 3.9 3.9

Antenna Gain (ISO) 18 18

Combiner Losses 4.7 4.7Slant loss 1.5 1.5

EIRP 52.7 52.7

PA Max Output 33 30

Rx Sensitivity -102 -102

Common Cable Losses 0 0

Antenna Gain (ISO.) 0 0

Body Losses 3.0 3.0

Indoor Penetration Factor 10.0 10Overlapping Margin 2.0 2.0

Shadow margin 6.7 6.7

Total Uplink Budget 136.2 dB 133.2 dB

Total Downlink Budget 135.0 dB 135.0 dBWorst Link Budget 135.0 dB 133.2 dB

Maximum Allowable Path Loss

GSM UPLINK/DOWNLINK LINK BUDGET

Base Station Transmitter/Receiver

Mobile Station Transmitter/Receiver

Margins



Sample UMTS Link Budget

Basic link budget

concept the same

Some parameters are

unique such as

loading factor /

interference margin

and Eb/N0

GeneralCS12.2 CS 64 PS 64 PS 128 PS 384

RX Frequency band (MHz) 1980 1980 1980 1980 1980

TX Frequency band (MHz) 2170 2170 2170 2170 2170

Spreading bandwidth (kHz) 3840 3840 3840 3840 3840

Thermal noise (kTB) (dBm) -108.2 -108.2 -108.2 -108.2 -108.2

Data rate (kb/s) 12.2 64 64 128 384

Processing gain (dB) 25 17.8 17.8 14.8 10

Maximum UE TX power (dBm) / MEAN 21 21 21 21 21

UE TX antenna gain (dBi) 0 0 0 0 0

Total UE TX EIRP (dBm) 21 21 21 21 21

BS RX noise figure (dB) 3.3 3.3 3.3 3.3 3.3

BS RX Eb/No (dB) 7.7 5.4 4.0 3.4 3.4

BS RX sensitivity (dBm) -122.1 -117.2 -118.6 -116.2 -111.5

BS RX antenna gain (dBi) 18 18 18 18 18

Slant losses 1.5 1.5 1.5 1.5 1.5

BS RX cable & connector losses (dB) 3.9 3.9 3.9 3.9 3.9

Maximum allowable isotropic path loss (dB) 155.7 150.8 152.2 149.8 145

Area Reliability desired 90.00% 90.00% 90.00% 90.00% 90.00%

Edge Reliability 82.76% 82.76% 82.76% 82.76% 82.76%

Total Standard deviation (dB) 8 8 8 8 8

Shadowing Margin(Including Soft Handover Gain)

Building/car penetration factor (dB) 10 10 10 10 10

Body loss (dB) 3 1 1 1 1

UL Interference margin due to traffic loading (dB) 3 3 3 3 3

Other margin/correction (dB) 0 0 0 0 0

Total required margin (dB) / UPLINK 18.6 16.6 16.6 16.6 16.6

Available Uplink Link Budget (dB) 137.1 134.2 135.6 133.2 128.4

Maximum Al lowable Upl ink Path Loss

Margins

2.6 2.6 2.6 2.6 2.6

UMTS UPLINK LINK BUDGET

User Equipment Transmit ter

Base Station Receiver



Propagation Models

The propagation models and propagation prediction tools used in GSM and

UMTS network design are similar Hata model typically used for GSM900 is not suitable for UMTS which is in therange of 2GHz

COST231 extended the applicability of the Hata model to higher frequenciesincluding those of the GSM1800 and UMTS frequency bands

The COST231 formula is:L = (44.9 6.55log (hb )) log (d) + 46.3 + 33.9log (f) 13.82log (hb) a (hm ) + Cm

a(hm): antenna height gain correction factor

a(hm) = (1.1log(f)

0.7)hm

(1.56log(f)-0.8)sf

f: center frequency (MHz)

hb: base station antenna height (m)

hm: mobile antenna height (m)

d: distance (km)

Cm: environmental correction factor

This model applies under the following conditions: f: 1,500-2,000 MHz

hb: 30-200 m

hm: 1-10 m d: 1-20 km

Same model used for UMTS like in GSM1800 after applying a simple correctionfactor of 33.9log(fumts/fgsm).



Same Propagation Prediction Tool

Nortel 2G/3G radio design tool:iPlanner

PC Windows2000/NT

Used for GSM, IS-95 CDMA, cdma2000,and UMTS RF design

Traffic spreading algorithm applied forCDMA-based technologies


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Presentation Name - 6NORTEL NETWORKS CONFIDENTIAL

UMTS Considerations in Planning Tool

UMTS capability W-CDMA

Multi-services

Speech

Data: LCD64, 144, 384, 2048

UDD64, 144, 384, 2048

Multi-carriers

Multi-users

Coverage prediction Pathloss calculations

Coverage based on design thresholds

WCDMA simulations

UMTS

Cell

Planning

Tool

Quality

of

Service

Coverage

Maps

UMTS Cell

Planning Tool


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Summary of 2G & 3G Design Similarities

Same basic link budget concepts Parameters such as shadowing, in-building penetration, and body

loss are independent of cellular technology

Same radio propagation and prediction tools can

be used


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Content

1. 3G and 2G Design Similarities

2. 3G and 2G Design Differences




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Goal to Balance QOS,

Coverage, Capacity, Cost

Balance: Capacity

CoverageQOS

COST

Key Differences in RF Design

WCDMA RF Characteristics compared to GSM

Coverage more Uplink Limited. GSM practice of balanced link budget not

possible.

Coverage quality sensitive to traffic load. (At Higher Spectral Efficiency)

Cell capacity usually limited by Downlink.

All neighbor cells are attenuated Co Channel interferers.

Soft Capacity Shared over Clusters of Cells. Self Adapts to Hotspots Faster Handoff Processing essential

WCDMA RF Design for Voice & Packet Data

Interference Control Critical for all CDMA Technologies.

Cloverleaf Pattern with 65 Deg Beam preferred for Macrocells with

optimized azimuth .

Microcells can be Co Channel to Macro Layer.


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CDMA RF Design Strategies (1/2)

1. Server dominance is critical

Impact on radio capacity, hardware provision, call setup reliability, voice

quality, data throughput and call drop rate

Weak Ec/Io and high soft HO rate may be sign of no dominant server

2. Low antenna height variance

High antenna height variance may result in pilot pollution

3. Locating sites near the traffic Power control is central to CDMA-based technology, low overall

interference will result in capacity gain

4. Careful antenna selection to capture target traffic

Not just to increase RSSI as in GSM but to capture traffic from a specific

spot5. Consider a variety of radio bearers

Consider the trade-off between coverage and guaranteed bearer


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CDMA RF Design Strategies (2/2)

6. User segmentation

User segmentation allows cost effective use of capacity

7. High power PA

In a asymmetric cell design use of high power PA reduces site count

significantly

8. Micro cell strategy

Carefully planning can allow effective use of micro cell in certain scenario

9. Repeater

Repeater is cost effective for addressing indoor or coldspot coverage

extension

Engineering and optimization of repeater must be done only by experts to

avoid polluting the network10.CDMA experience & engineering tools

The use of CDMA experience together with effective engineering tools will

shorten the learning curve


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WCDMA Design Parameters

Significant Parameters The most constraining

radio bearer (CS12.2, PS64,CS64, etc.) because this impacts

the required uplink Eb/N0

Target BLER because this also

impacts the required uplink Eb/N0

Common pilot Ec/I0 at the

cell edge. The design target isoften -12 dB.

Mobile transmit power. Thedesign targetincluding all

marginsis 21 dBm or less.

Less Significant Parameters Downlink RSSI

Downlink common pilot Ec

Actual BLER


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Optimization Metrics

Dropped callsand unsuccessful call attempts:

plots, counts, and percentages

Actual BLER, uplink and downlink

Common pilot Ec/I0only to indicate poorly-

optimized coverage, pilot pollution, and no dominant

server problems

Number of cells/radio links per user

Mobile transmit power

Capacity per cell


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Soft Handover Gain

Soft handover gain

is manifested in alower averagemobile transmitpower

Soft handover is animportant tool toextend cell coverage

Soft handover intransition zonesmust be carefullyplanned

20 15 10 5 0 5 10 15 20

0

0.2

0.4

0.6

0.8

1

Log(Signal Power)

Single Server

Two Servers

(50% correlation)

Two Servers

(0% correlation)

SHOGain

@

90%

Rel.

Required link

margin for two

servers @ 90%

reliability

Required link

margin for one

server @ 90%

reliability

0.9

20 15 10 5 0 5 10 15 20

0

0.2

0.4

0.6

0.8

1

20 15 10 5 0 5 10 15 20

0

0.2

0.4

0.6

0.8

1

Log(Signal Power)

Single Server

Two Servers

(50% correlation)

Two Servers

(0% correlation)

SHOGain

@

90%

Rel.

Required link

margin for two

servers @ 90%

reliability

Required link

margin for one

server @ 90%

reliability

0.9

Soft HO gainis unique to WCDMA

Reliability


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Capacity-Coverage Tradeoff

Capacity-coverage trade-off represents the relationship between the cell sizeused for design versus the capacity the cell is able to offer.

In GSM, cell size is defined to guarantee a certain quality of coverage.

In UMTS cell size is defined by the uplink link budget for a maximum uplinkcapacity, and downlink capacity is deduced. The larger the cell, the smaller

the uplink capacity by definition.but also the bigger the power needed peruser, hence the smaller the downlink capacity, PA power being the sharedresource.

UMTS design calls for an optimum cell size for a maximum capacity.

Capacity

Cell size

GSM

Hardware upgrade

Zone A

Cell splitting :site densification

Zone B

UMTS

Too much interference

Killed capacity

Zone D

Too big cell

Coverage capacity trade-off

Zone C

Capacity

Cell size

GSM

Hardware upgrade

Zone A

Cell splitting :site densification

Zone B

UMTS

Too much interference

Killed capacity

Zone D

Too big cell

Coverage capacity trade-off

Zone C

Optimal Cell Size determined by

Capacity -Coverage Tradeo ff

Optimal cell size for

capacity and coverage

(Km)


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Asymmetric Model @384kbpsDL & 64kbpsUL (already conditioned by cell size)

Power

Path loss UL

The 45W amplifierprovides the

necessary power,

unlike a 20W

solution.

Power

Path loss DL

iBTS Sensitivity

UE Sensitivity

The UL range is limited by low UE TX

power (Max = 250mW, Min


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High Power PA Benefit for Asymmetric Cell

Design

With asymmetric call profile cell coverage can be enhanced

using high power PA, thus reducing site count.

Up to 40% reduction in cell sites possible with

Asymmetr ic Cel l Design


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Economics Comparison(Based on High Power PA)

PA cost / Capacity45W MCPA 20W SCPA,, OTSR 38 (OTSR) 100 (STSR1),,,,

OTSRSRST2 38 (OTSR)96 (STSR1)55 (STSR2)

100 (STSR1)100 (STSR1)100 (STSR2)

, STSR1 - STSR3 96 (STSR1)55 (STSR2)75 (STSR3)100 (STSR1)100 (STSR2)100 (STSR3)

(CBD), (, , )STSR2STSR3TD 55 (STSR2)75 (STSR3)37 (STSR3TD)

100 (STSR2)100 (STSR3)100 (STSR3TD)


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Summary of 2G & 3G Design Differences

Coverage + Interference analysis required todeliver good network performance

Uniform antenna height more crucial to preventnetwork performance degradation such as Pilotpollution

Soft Handover resulting in effective coveragegain

Maximum optimal cell size determined byCapacity-Coverage tradeoffs Cell coverage is limited by uplink, Cell capacity is limited by

downlink

Asymmetric Design resulting in 40% reduction insite counts


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Content






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Receiver sensitivity (xkbps)

BS Receiver

Maximum Noise Floor

Lowest Despread Signal

BTS

Cell B reathing

Eb/No

ProcessingGain

xkbps

UE2 UE3xkbps

Eb/No

ProcessingGain

UE1

xkbpsUE4

xkbps

The more loaded the cell, the smaller the cell.

WCDMA Cell Loading Effect


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Cell Breathing

Cell breathing not a significant issue

Cell breathing accounted for in design. Effective service

area does not change in full load per design.

Link budgets include numerous margins such as cell

loading, shadowing margin, body-loss margin, cell loading

and in-building penetration margin.

BTS

Cell Breathing

x kbps

UE2 UE 3x kbps

UE1

x kbps

UE4

x kbps

Cell breathing effects: Nullified by the RF design process

BTS

Cell BreathingCell Breathing

x kbps

UE2 UE 3x kbps

UE1

x kbps

UE4

x kbps

Cell breathing effects: Nullified by the RF design process

Cell Breathing effects can be captured by

including cell loading factor in the link budget


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WCDMA Capacity Characteristic

WCDMA capacity is downlink limited

Site Spacing

C

apacity

Self -interferenceDominates

Thermal NoiseDominates

Downlink Capacity Characteristic

Site Spacing

C

apacity

Self -interferenceDominates

Thermal NoiseDominates

Downlink Capacity Characteristic


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Downlink link budget & link balance

Key parameters for DL link budget not generalizable

Downlink Eb/No is not predictable in CDMA-

based system

WCDMA self-interference received by a mobile is

extremely sensitive to the mobiles location

Auto-balancing in WCDMA

Power control algorithms will try to achieve target

BLER

In effect, UMTS (or CDMA-based systems) isauto-balancing


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CscrambC

ch& C

ch

Code Division - User distinguishes By Codes

Channel #i Channel #i

Channel #i

Cscramb : Scrambling Code (distinguishes Cells and Mobile Users)

Cch : Channelization Code (distinguishes one Communication Channel direction)

Cscramb

Cch

Cscramb

Cch

Cscramb

Cch

Cscramb

Cscramb

Cch

Sector 1

Sector 2

Sector 3


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Scrambling Code Planning

Scrambing code planning is not as complicated

as frequency planning in GSM

From Nortel CDMA experience scrambling code

reuse pattern can be easily planned and usually

requires little change after deployment

Can be achieved simply by ensuring that no cells

have neighboring cells whose scrambling codes

are the same

Scrambling Code reuse pattern is much

simpler than frequency reuse in GSM


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Compressed Mode Concept

Transmission gaps provided for UE to retune and search inter

frequency GSM handoff candidiates at UMTS cluster Edge.

UE transmits at x2 Rate immediately before and after gap using

secondary spreading codes (non orthogonal) Other options

include reduced interleaving on primary code.

Interleaved sequences required to search GSM RSSI and BSIC

Pattern for GSM RSSI measurements

GSM RSSI

Measurements Initial BSICIdentification

Pattern for initial BSIC identificationPattern for BSIC reconfirmation

BSIC

Reconfirmation GSM RSSIMeasurements Initial BSICIdentification


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Compressed mode issue

Why measurement assisted hard HO not popular in CDMA?

Impact to voice quality due to high frequency search Impact to radio capacity may be significant

Compressed Mode in UMTS

Degree of improvement not clear

Power control issue (no power control while searching)

Reduced spreading factor may cause code managementissue

Problems may be significant in heavily loaded cells

Hard HO issue cannot be completely addressed bycompressed mode

Hierarchical cell structure (HCS) is not equally applicable in

UMTS as in GSM

Compressed Mode is not the only

hard handoff solution


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CM Capacity Impact

Capacity decreases in larger clusters.

Tolerable if UMTS deployed initially in small

clusters with low traffic expectations.

Blind Hard Handoff to GSM should be

considered

RSSI CM Measurement Trigger (dBm) - -90 -85

GSM Border Handoff Thresh (dBm) -95 -95 -95

% Users in Compressed Mode 0 5.1 11.8

% PA Power on Secondary Codes 0 17.5 33

Carried Voice Traffic (Erlangs) 42 32 23% Erlang Capacity 100.0% 74.4% 53.5%

RSSI trigger level has a huge impact on the

applicability of Compressed Mode

Based on simulations


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UMTS & CDMA2000

(,)800Hz( )1500Hz

(based onvoice activity)

(basedon RF condition)

IS-95

GSM

QPSK()BPSK()QPSK()BPSK()

20ms10msGPS(GPS),

1.2288Mcps3.84McpsFDDFDDcdmacdma1.25MHz5MHz

cdma2000UMTS


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Content






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Topics

Design targets : Coverage

Availability

Capacity

Reliability

Interference Control Site Selection Concerns

Co-location Concerns

Load-Sharing Concerns

RF Design Rules

Indoor Coverage Strategy

Hotspot Coverage Strategy


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Coverage Requirement

Service area Need to define the most constraining service

Need to identify areas of particular importance just like GSM

Service availability Usually ranges from 75-95%

High availability will mean high site count

Rollout Phasing and Contiguous Coverage Contiguous coverage is more cost effective

Best practice is to have single urban service area expanding over

time towards suburban and rural


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Continuous Coverage & Phased RolloutPhase 1

The initial UMTS build-out is recommended to be coverage-oriented Coverage should be continuous to minimise inter system handoffs,

increasing demand on network resources and may result in higher drop-callrates

The coverage should start from dense-urban, urban area and expanding tosub-urban and rural area

Since UMTS/CDMA network is interference limited, the Ec/Ioalso need to be evaluated. (see fig. 2)

Coverage Plot (fig. 1) Ec/Io Plot (fig.2)

Potential interference

area, but not critical in

Phase 1 due to low traffic


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Coverage Plot (fig. 1) Ec/Io Plot (fig. 2)

Continuous Coverage & Phased RolloutPhase 2

During Phase 2, increasing UMTS subscribers requires new

capacity cells to be added (see fig. 1) and coverage area is

expanded at the same time

The interference area observed in Phase 1 is resolved by adding the new

capacity cells (see fig. 2)

Add capacity cellsto handle traffic increase

in Phase 2


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Quality, Traffic and Site Selection

BLER target is a trade-off between quality and

radio capacity From IS95 CDMA and CDMA2000 experience 2% target for voice

is good compromise

CSD (Video) requires anywhere from 1% to 5%

Packet bearers are typically configured from 5% to 10%

Site selection When reusing existing sites, care must be taken to reduce irregular

site spacing and great variation in antenna height

Reuse existing site only if it is suitable for UMTS

Traffic management Experience shows best strategy is to migrate heaviest users to dual

mode service

Ensure dual mode users use UMTS whenever possible


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UMTS Site Selection

UMTS/CDMA Network is Interference limited System

In GSM system, RF design is measured by RSSI level in coverage

area (see fig. 1) , but in CDMA/UMTS RF design, interference must be

evaluated as well (see fig. 2)

100% GSM & UMTS blind co-location may cause problems in UMTS

system, such as pilot pollution due to too much interference

Coverage Plot (Fig.1) Pilot PollutionArea due to too

much interference

Ec/Io Plot (Fig.2)

Minimis ing Interferenceis a primary design target


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Load Sharing

Load sharing between UMTS carriers is essential to optimise

UMTS radio resources Deploy multi-carrier management system for efficient sharing of UMTS carrier

capacity

3G/2G Load Sharing is targeted to achieve resource

utilisation efficiency across the unified 3G/2G spectrum

Load Sharing is achieved by Overload prevention & Load balancing In the initial phase of UMTS deployment, primary objective is

to achieve network stability and optimisation

Frequent handovers between systems has an impact on network performance

and end user experience

Standardisation of Iur-g to enable cell loading information transfer between

GSM and UMTS not yet mature

Phased approach required to achieve radio resource

utilisation efficiency across unified 2G/3G spectrum

3G/2G Load Sharing is a long term objective


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3G/2G Load Sharing:UMTS network roll-out recommendations

Essential Mobility

3G to 2G mobility in idle mode 3G to 2G mobility in connected mode

2G to 3G mobility in idle mode

2G to 3G mobility in packet ready mode

3G/2G PHASE I

Enhancements / Segmentation

2G to 3G HO CS domain

Maximize UMTS capacity through

iMCTA for multi-carriers

3G/2G PHASE II

Advanced Multi-Layer Management

iMCTA based on Load, Priority, &

Service

unifiedRRM

3G/2G PHASE III


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3G/2G Load Sharing:

3G/2G Mobility Considerations

Two major types

Coverage fill-up - Rescue Because UMTS coverage may be limited at network launch, it can

be complemented with GSM coverage in a seamless manner for

the end user.

During a first phase, Mobility occurs mainly for radio reasons, in

order to maintain the call across the combined 3G/2G coverage

areas.

Network optimization - Preventive During network extension and optimization, it may be useful to

introduce load sharing and service segmentation

Finally, during network growth and densification, an efficient multi-

layer management can optimize the radio resources across 2G and

3G networks


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Key RF Design rules

RF Coverage contro lis the most important

optimization factor

Cell edge rel iabi l i tyand building penetration loss: if too high pilot pollution

Use downt i l tand/or reduce heightto confine

coverage

Create dom inant server area

Pilo t Ec /Iois the important threshold, not signal

level

Analysis result depends very much on traffic

distribution

Coverage & Interference Control is key


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Frequent problems encountered in CDMA

RF optimisations

Directing the energy to only the desired coverage area for that sector

Selecting proper horizontal and vertical patterns Typical Horizontal antenna pattern should be 65 degrees

Wide horizontal patterns make excessive soft handoff

Narrow horizontal patterns leave nulls

Typical Vertical antenna pattern should be 7 degrees, with 4 degrees electrical downtilt Wide vertical patterns result in poor coverage control

gives poor building penetration and reverse link interference.

Excessive sector overlap within a site increases system noise floor

Increases soft handoff and expands neighbor lists

Degrades Ec/Io

Reduces capacity

Excessive overlap between sites

increases system noise floor Increases soft handoff and expands neighbor lists beyond second and third tiers

Degrades Ec/Io and creates pilot pollution

Reduces capacity

RF Optimisation usually involves minimising

interference to improve radio capacity


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RF Optimisation

Nortel use in-house developed RF optimizer toprocess drive test data

RF Optimizer is developed as a result of Nortel

Networks experience in CDMA RF optimisation

Pilot pollution region

resolved

AfterBefore


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Indoor Coverage Strategy

In Phase 1, most office and residential buildings can be

covered by using outdoor Macro site penetrating indoor i.e.maximizing outdoor coverage is primary objective

Shopping malls and deep indoor locations can be covered by using indoor

antenna distribution system

Indoor locations with high isolation (e.g. underground car

park) may use repeater or micro cell Incorrect repeater deployments may cause interference which impact

network performance

Micro cell solution is more expensive than repeaters for coldspot coverage

extension

HSDPA will provide additional flexibility in the near future

WLAN may also be considered

H C C id i


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Hotspot Coverage Considerations

UMTS hotspot issues are addressed by Site splitting

Increase # of carriers

Micro cell approach (island implementation) is not appropriate

Increased interference between macro and micro layer = Pilot pollution

Increased hard handoffs between micro and macro layer resulting in highereffective drop call rate

Careful implementation of the hotspot capacity solution to

minimise

Pilot pollution

Increased hard handoffs

Nortel Networks has a Twin cell product feature

Improve overall cell capacity for small focused area

High percentage of handoffs in hotspot performed through softer handoffs,

improving success rate of inter-cell handoffs

RF C l ti ith Oth S t (1/4)


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RF Co-location with Other Systems (1/4)

RF co-existence is an extremely broad and

complicated topic Location and deployment dependent

Types of interference Wideband noise

Spurious emissions Inter-modulation products

Uncoordinated frequency bands

S f RF I t f (2/4)


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Sources of RF Interference (2/4)

BS transmitter from one network interferes with

BS receiver from a different network

MS transmitter from one network interferes with

BS receiver from a different network

BS transmitter from one network interferes MS

receiver from a different network

MS transmitter from one network interferes with

MS transmitter from a different network

T h l ifi C id ti (3/4)


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Technology-specific Considerations (3/4)

Global considerations GSM900/ETACS, GSM1800, GSM-R and UMTS

China-specific considerations CDMA1900 (WLL) downlink interferes with UMTS uplink

UMTS uplink interferes with PHS/TD-SCDMA uplink

PHS/TD-SCDMA uplink interferes with UMTS uplink PHS/TD-SCDMA downlink interferes with UMTS uplink

S S l ti f RF C l ti (4/4)


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Some Solutions for RF Co-location (4/4)

No generic solution for all RF co-existence issues Each deployment must be assessed individually

Some example solutions Separation: ensuring as much path loss between source and victim

systems as possible

Co-location: ensuring source and victim systems share the samecell site

Filtering: using antennas and filters


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03%2E Key UMTS Radio Design Strategy 26 Considerations

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Transcript of 03%2E Key UMTS Radio Design Strategy 26 Considerations