lte planning and ion
TRANSCRIPT
LTE Radio Planning and Optimisation
Contents
� LTE Radio Planning Basics
� LTE Link Budgets
� LTE Capacity Planning
� Optimisation Introduction
� Self Organising Network Concepts
1
Radio Planning Basics
High Level Design Life Cycle
1
3
How many eNBs tosatisfy objectives?• Capacity• Coverage
How many sitesavailable?
Objectives satisfiedwith available sites?
Pre-Build OptimisationEnsure CAPEX Efficiencyand optimal performance
Information Required – Phase 1
Generally Known Data
� Frequency Band
� Amount of Allocated Spectrum
� Channel Bandwidth
� Equipment Performance
Market Research Data
8
4
Market Research Data
� Service Area
� Population Density
� Population Demographic
� Population Penetration
� Expected level of service
LTE Link Budgets
Link Budget :– System Gain
TxPA
LF+C
GAnt
GDiv
EiRP
GAnt
Sys Gain
6
UEIRLmin
LF+C
GAnt
Rxth
Sys GainUL = (TXPAUE + GAntUE) – (RxTHeNB + LeNB – GANTeNB – GDiv)
Sys GainDL = (TXPAeNB – LeNB + GAnteNB + GDiv) – (RxTHUE – GANTUE – GDiv)
Link Budget : – MAPL, Spending the Budget
2
Sys G
ain MAPL Distance
7
Sys G
ain
Fade Margin 8 – 12 dB
Building Margin 5 – 30dB
Body Margin 0 – 3 dB
Using MAPL to Find Distance
Propagation
MAPL
FrequencyHeight
Antenna
Height
Clutter Terrain
8
PropagationModel
Clutter Terrain
Distance
Performance KPIs
Noise and Interference
Signal Strength
64QAM 16QAM QPSK
9
64QAM 16QAM QPSK
• Cell Edge Throughput• RSRQ• RSRP• RSSI• SNR• Area Availability• Cell Edge Availability
Defining RSRP, RSSI and RSRQ
14
LTE Resource BlockRs
10
Rs
Rs
Rs
UE Radio Measurements
13
11
RSRP and RSRQ Targets
15
12
LTE Capacity Planning
Capacity in LTE
� LTE supports Adaptive Modulation and Coding
� Actual Capacity will depend on users location in the cell
� SINR is the most important planning KPI
� Average cell throughput will lower than quoted
maximums
14
5
The Capacity Planning Problem
100+ Mbps!Assumes good radio signal in
every part of the radio cell
15
QPSK16QAM64QAM
User Distribution in the Cell
� User Distribution will impact average cell throughput
� The resource scheduler in the eNB is very important
� Scheduling may be different between vendors
16
QPSK16QAM64QAM
~10% of Area
~15% of Area
~75% of Area
Average Cell Throughput
Mbps
Lower Average
Due to resource sharing
Between many users
Higher Peak Loads
due to less active users
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Average Busy Hour
Throughput
Average Non-Busy Hour
Throughput
time
Capacity Modelling
� Try to Determine what data the typical user will consume
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Capacity Modelling cont.
� Extrapolate consumption between subscriber population
� Make assumptions about “busy period” to obtain Data
Density
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Capacity Modelling cont.
� Use Link Budget and Sector Throughput to determine
number of radio cells
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Optimisation Introduction
Optimisation Context
1
22
Optimisation Targets
� Cell Edge Throughput 5-10Mbps
� RSRQ -7dB
� RSRP -75dB
� SNR >13dB
� Area Availability 90%
� Cell Edge Availability 75%
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� Cell Edge Availability 75%
� RF Optimisation Options
– Antenna Orientations, Tilt, Azimuth
– Transmit Power
– Antenna Height
– eNB Location
Mobility Optimisation� Initial Cell Selection
UE
Qrxlevmeas
Low QrxlevminQminoffset
24
High QrxlevminQminoffset
Srxlev = Qrxlevmeas – (Qrxlevmin+ Qrxlevminoffset) - Pcompensation
Cell Reselection
Sintrasearch
Snonntrasearch
No
Se
arc
hLT
E S
ea
rch
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IRA
T S
ea
rch
Rs = Qmeas_s +QhystRn = Qmeas_n + Qoffset
Rn > Rs > Treselection
Other Mobility Considerations� IRAT Cell Reselection Decisions
UE
LTE
UMTS
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GERAN
• Measurement Thresholds
• Cell Priority
• Mobility Offset/Hyst
• Mobility Status (speed)
• Cell Ranking
Other Mobility Considerations :- Handovers� LTE and IRAT Handovers
UE
LTE
UMTS
• Measurement/
Reporting
Thresholds
• Cell Priority
• Mobility
Offset/Hyst
• Mobility Status
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GERAN
(speed)
• Cell Ranking
• eNB makes H/O
Decision
• H/O Algorithm
Vendor/ Operator
Controlled
Self Organising Network Concepts
Optimisation for Future Deployments
� Self Organising/Optimising Networks
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SON Release 8
� Automatic Inventory
� Automatic Software Download
Focus is on initial equipment installation and integration
eNB Self Configuration
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� Automatic Neighbour Relation
� Automatic Physical Cell ID assignment
SON Release 9
� Mobility Robustness/Handover optimization
� RACH optimization
Provides SON functionality covering operational aspects
of already commercial networks, in particular key aspects
related to network optimization procedures.
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� RACH optimization
� Load Balancing optimization
� Inter-Cell Interference Coordination
SON Release 10
� Coverage & Capacity optimization
� Enhanced Inter-Cell Interference Coordination
Cell Outage Detection and Compensation
Provides a richer suite of SON functions for macro and
metro networks overlaid on and interoperating with existing
mobile networks.
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� Cell Outage Detection and Compensation
� Self-healing functions
� Minimization of Drive Testing
� Energy Savings
SON Architecture
� Centralised SON� A centralized architecture approach can be used for deploying real-time
SON functions, such as Automatic Neighbor Relations and Automatic
Physical Cell ID.
� The OAM must also handle large amounts of data in order to make the
localized SON decisions across the network
� Multi-Vendor support may be difficult
33
EPC
eUTRAN
eUTRAN
eUTRAN
OAM
SON
SON Architecture
� Distributed SON� The distributed architecture leverages smart, autonomous network elements
with local SON decision making
� This reduces the complexity, footprint and availability requirements of the
OAM
� X2 requirements are more complex
� Easier in a multi-vendor system
SONSON
34
EPC
eUTRAN
eUTRAN
eUTRAN
OAM
SONSON
SONSON
SONSON
SON Architecture
� Hybrid SON� More complex solution
� OAM can make long term optimisation decisions and eNB can deal with the
real time optimisation of load and interference
� Should be possible to build effective systems in a multi-vendor system
SONSON
35
EPC
eUTRAN
eUTRAN
eUTRAN
OAM
SONSON
SONSON
SONSON
SON
LTE Training:- Telecoms Academy
� Visit Helen Robinson on Stand 23
� LTE Technical and non-Technical Overviews
� LTE Radio Planning and Optimisation
� LTE Core Network Planning and Dimensioning
� eUTRAN Protocols and Signaling
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� eUTRAN Protocols and Signaling
� LTE and IMS
� miniMBA with LTE Focus
� Distance Learning Course with LTE focus
