[PPT] - Effectiveness of Cell Outage Compensation in LTE Networks Mehdi PowerPoint Presentation

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Effectiveness of Cell Outage Compensation in LTE Networks

Mehdi Amirijoo, Ericsson, Sweden Ljupco Jorguseski, TNO, The Netherlands Remco Litjens, TNO, The Netherlands Renato do Nascimento, Alcatel-Lucent, Portugal CCNC ‘11 January 10, 2011 Las Vegas, USA

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INTRODUCTION
ASSESSMENT APPROACH
NUMERICAL RESULTS
CONCLUDING REMARKS

OUTLINE

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INTRODUCTION
ASSESSMENT APPROACH
NUMERICAL RESULTS
CONCLUDING REMARKS

OUTLINE

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LTE
Mobile cellular network technology
E-UTRAN, a.k.a. ‘Long Term Evolution’
Standardised by 3GPP R8-…
3.9G successor to UMTS
Key features
OFDM
MIMO
SON
…

INTRODUCTION

1989

OBLB

1980

NMT 900

1985

NMT 450 + HSDPA + HSDPA

2006

UMTS UMTS

2003

UMTS + HSPA

2001

GSM

1994

+ GPRS LTE

2011

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INTRODUCTION

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Measurements Detection Compensation Operator policy: Coverage, QoS Control parameters Coverage/QoS map estimation

Cell outage management / self-healing
Automatic detection and compensation of ‘outages’
eNodeB failure, cell failure,

physical signal/channel failure

Enhances robustness/resilience

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Cell outage management / self-healing
Control parameters
Transmit power settings
Antenna downtilt
Azimuth/beamforming
Scheduler’s fairness parameter
Intra/inter-RAT handover parameters, load balancing
Neighbour cell lists
…

INTRODUCTION

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Cell outage management / self-healing
Control parameters
Transmit power settings

INTRODUCTION

PMAX = PPILOT + PDATA = fixed
Raising PPILOT increases coverage,

but decreases PDATA and hence the traffic handling capacity/quality

An increased coverage also implies

more absorbed traffic, hence more resource sharing and less per-user QoS DOWNLINK

P0 ≡ target received power density (per RB)
Reducing P0 lowers inter-cell interference

levels and hence increases coverage

Reducing P0 lowers the achievable MCS

and hence throughput/QoS per RB

An increased coverage also implies

more absorbed traffic, hence more resource sharing and less per-user QoS UPLINK

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Cell outage management / self-healing
Control parameters
Antenna downtilt

INTRODUCTION

Raising TILT increases coverage,

but also increases inter-cell interference

An increased coverage also implies

more absorbed traffic, hence more resource sharing and less per-user QoS

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Objective

INTRODUCTION

TO ASSESS THE EFFECTIVENESS OF PPILOT, P0 AND TILT IN MITIGATING THE EFFECTS OF CELL OUTAGES IN DIFFERENT SCENARIOS

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INTRODUCTION
ASSESSMENT APPROACH
NUMERICAL RESULTS
CONCLUDING REMARKS

OUTLINE

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Scenarios
Diverse aspects are of potential interest …
Site density
Traffic load
Service mix
Spatial traffic distribution
User mobility
Propagation environment
…

ASSESSMENT APPROACH

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Scenarios
COVL

Coverage-oriented network layout with low traffic load

CAPL

Capacity -oriented network layout with low traffic load

CAPM

Capacity -oriented network layout with medium traffic load

CAPH

Capacity -oriented network layout with high traffic load

ASSESSMENT APPROACH

Capacity-driven layout Coverage-driven layout Inter-site distance 500 m 2200 m Antenna downtilt 15o 5o System bandwidth 10 MHz PMAX,BS, PRS, PMAX,UE 46 dBm, 33 dBm, 25 dBm Path loss 128.1 + 37.6 log10 r, with r in km Shadowing σ = 8 dB, inter-site correlation of ½, decorrel. distance = inter-site distance / 15 Antenna model 3GPP 3D model Noise level

199 dBW/Hz in DL, -195 dBW/Hz in UL

Service Generic elastic data service with a requested throughput of 1 Mb/s (DL) & 250 kb/s (UL)

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Performance metrics
Coverage probability
Uplink/downlink user throughput
Fraction of satisfied users, where ‘satisfied’ is …
Covered
Uplink throughput ≥ α × 250 kb/s
Downlink throughput ≥ α × 1 Mb/s
... and α reflects the operator policy in that

it expresses the relative importance of coverage and quality

When applicable, metrics are

assessed over first tier of tells surrouding the outage area

ASSESSMENT APPROACH

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INTRODUCTION
ASSESSMENT APPROACH
NUMERICAL RESULTS
CONCLUDING REMARKS

OUTLINE

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PRE-OUTAGE SITUATION POST-OUTAGE SITUATION WITHOUT COMPENSATION UPLINK USER THROUGHPUT COVERAGE PROBABILITY DOWNLINK USER THROUGHPUT POST-OUTAGE SITUATION WITH OPTIMISED PPILOT PRE-OUTAGE SITUATION POST-OUTAGE SITUATION WITHOUT COMPENSATION UPLINK USER THROUGHPUT COVERAGE PROBABILITY DOWNLINK USER THROUGHPUT POST-OUTAGE SITUATION WITH OPTIMISED PPILOT PRE-OUTAGE SITUATION POST-OUTAGE SITUATION WITHOUT COMPENSATION UPLINK USER THROUGHPUT COVERAGE PROBABILITY DOWNLINK USER THROUGHPUT POST-OUTAGE SITUATION WITH OPTIMISED PPILOT

NUMERICAL RESULTS

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PRE-OUTAGE SITUATION POST-OUTAGE SITUATION WITHOUT COMPENSATION UPLINK USER THROUGHPUT COVERAGE PROBABILITY DOWNLINK USER THROUGHPUT POST-OUTAGE SITUATION WITH OPTIMISED P0 PRE-OUTAGE SITUATION POST-OUTAGE SITUATION WITHOUT COMPENSATION UPLINK USER THROUGHPUT COVERAGE PROBABILITY DOWNLINK USER THROUGHPUT POST-OUTAGE SITUATION WITH OPTIMISED P0 PRE-OUTAGE SITUATION POST-OUTAGE SITUATION WITHOUT COMPENSATION UPLINK USER THROUGHPUT COVERAGE PROBABILITY DOWNLINK USER THROUGHPUT POST-OUTAGE SITUATION WITH OPTIMISED P0

NUMERICAL RESULTS

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PRE-OUTAGE SITUATION POST-OUTAGE SITUATION WITHOUT COMPENSATION UPLINK USER THROUGHPUT COVERAGE PROBABILITY DOWNLINK USER THROUGHPUT POST-OUTAGE SITUATION WITH OPTIMISED TILT PRE-OUTAGE SITUATION POST-OUTAGE SITUATION WITHOUT COMPENSATION UPLINK USER THROUGHPUT COVERAGE PROBABILITY DOWNLINK USER THROUGHPUT POST-OUTAGE SITUATION WITH OPTIMISED TILT PRE-OUTAGE SITUATION POST-OUTAGE SITUATION WITHOUT COMPENSATION UPLINK USER THROUGHPUT COVERAGE PROBABILITY DOWNLINK USER THROUGHPUT POST-OUTAGE SITUATION WITH OPTIMISED TILT