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ATOLL LTE FEATURES
Training Program
1. LTE Concepts
2. LTE Planning Overview
3. Modelling an LTE Network
4. LTE Predictions
5. MIMO Modelling
6. Neighbour Allocation
7. Automatic Resource Planning
8. Frequency Plan Analysis
9. Monte-Carlo Based Simulations
10. Using Drive Tests
11. Terminology and Concepts
© Forsk 2009 Slide 2 of 149Confidential – Do not share without prior permission
1. LTE Concepts
Context and background
OFDM/OFDMA basics
© Forsk 2009 Slide 3 of 149Confidential – Do not share without prior permission
Context and Background
What is LTE?
What is 4G?
Why LTE?
LTE deployment
RF planning/optimisation tool requirements for LTE
Evolution of LTE
© Forsk 2009 Slide 4 of 149Confidential – Do not share without prior permission
What is LTE?
LTE = Long Term Evolution
3GPP1’s project name for Evolved UTRA2 (e-UTRA)
Next generation of 3GPP-based mobile networks(GSM/GPRS/EDGE, UMTS/HSPA, and TD-SCDMA)
One of the 3 standards on which 4G cellular networks will be based
LTE from 3GPP
WiMAX from IEEE and the WiMAX Forum
UMB3 from 3GPP2
1 Third Generation Partnership Project
2 UMTS Terrestrial Radio Access
3 Ultra Mobile Broadband
© Forsk 2009 Slide 5 of 149Confidential – Do not share without prior permission
What is 4G?
Provides improvements over existing 2G and 3G networksHigh data rates at high mobile speeds:~100Mbps in DL, 50Mbps in UL with MIMO
Inter-working and support for mobility:Handovers to 3G and 2G layers and roaming
Service and content convergence:VoIP, download, streaming, TV, VOD, etc.
All IP backbone
Based on some form of OFDM
Implement smart antenna/MIMO techniques
Use higher order modulation techniques
Support for scalability: Channel bandwidth adaptation
© Forsk 2009 Slide 6 of 149Confidential – Do not share without prior permission
What is 4G?
Evolution of Mobile Technologies
200820072006 2009
3G LTE
All-IPOFDM MIMO AAS
WiMAX 802.16m
All-IP OFDM MIMO
WiMAX 802.16e-2005
All-IPOFDM MIMOAAS AAS
CDMA2000 EV-DO Rev.A
IP transport
EV-DO Rev.C
All-IPOFDM MIMO AAS
HSDPA / HSUPA
IP Transport
HSPA+
MIMO All-IP
EDGE Evolution
© Forsk 2009 Slide 7 of 149Confidential – Do not share without prior permission
What is 4G?
Evolution of 3GPP StandardsRelease ’99: UMTS FDD
Release 4: UMTS TDD + FDD Repeaters
Release 5: HSDPA
Release 6: HSUPA (Enhanced Uplink) + MBMS
Release 7: HSPA+ (2x2 MIMO, Higher Order Modulation, etc.)
Release 8: LTE FDD and TDD
© Forsk 2009 Slide 8 of 149Confidential – Do not share without prior permission
Why LTE?
Huge potential market shareGSM (80.4 % market share)Around 670 operators in ~200 countriesMore than 3 billion subscribers worldwide
UMTS HSPA (7.8 % market share)Around 105 operators in ~47 countriesNearly 300 million subscribers worldwide
Potential market share for UMB: 11 %
EconomicPossibility to reuse part of existing 3Gequipment hardware with software defined radio
Spectrum already allocated to operators
Convergence of market and user needsMulti-play services (voice, data, broadcast, …)
Number of mobile subscriptions worldwide: > 3.8 billion
© Forsk 2009 Slide 9 of 149Confidential – Do not share without prior permission
Improvements over 3G (UMTS HSPA)
Why LTE?
Data RatesData RatesDL: 14.4 Mbps &DL: 14.4 Mbps &
UL: 5.7 MbpsUL: 5.7 Mbps
Highly sensitive toHighly sensitive toInter-symbol InterferenceInter-symbol Interference
Highly sensitive toFrequency Selective
Fading
Min 5 MHzMin 5 MHzSpectrumSpectrumLTE vs. 3GLTE vs. 3G
OrthogonalSubcarriers
Cyclic Prefix
Up to 100 Mbps DL and 50 Mbps UL
Min 1.4 MHz
© Forsk 2009 Slide 10 of 149Confidential – Do not share without prior permission
LTE Deployment
1st phase:A few trial sites in urban areas where provision of high data rate services has market potential
Site locations probably the same as existing 3G sites
Spectrum sharing with existing 3G cell (1 carrier dedicated to the trial LTE layer)
2nd phase:Replacement of 3G sites with on-air LTE sites, or
Co-existence of 3G and LTE coverage layers
High Speed High ThroughputHandovers
© Forsk 2009 Slide 11 of 149Confidential – Do not share without prior permission
Migration from any 3GPP technology to LTE
Rational choice for GSM and GSM/UMTS operators
Some CDMA operators might also opt for LTE instead of UMB
Very few GSM operators would opt for WiMAX
Rarely any green-field scenarios
LTE Deployment
GSM UMTSGPRSEDGE
HSPA LTE
Non-3GPPTechnologies
© Forsk 2009 Slide 12 of 149Confidential – Do not share without prior permission
Evolution of LTE
Future: IMT-AdvancedMost 4G networks will move to
• LTE Advanced• WiMAX 802.16m
100 Mbps to 1 Gbps in DL• 100 Mbps for fast moving users• 1 Gbps for slow to stationary users
© Forsk 2009 Slide 13 of 149Confidential – Do not share without prior permission
OFDM/OFDMA Basics
OFDM definition and differences between FDM and OFDM
Advanced OFDM : OFDMA
Multiple access techniques and duplexing methods
Benefits of OFDM/OFDMA
OFDM/OFDMA in LTE
© Forsk 2009 Slide 14 of 149Confidential – Do not share without prior permission
What is OFDM ?
OFDM = Orthogonal Frequency Division MultiplexingAlso known as Discrete MultiTone (DMT) or Multi-Carrier Modulation (MCM)
Advanced form of Frequency Division Multiplexing (FDM)• FDM : single modulated radio signal per user
• OFDM : hundreds to thousands of separate radio signals (subcarriers) spread across a wideband channel. In OFDM, the sub-carrier frequencies are chosen so that the subcarriers are orthogonal to each other
Time period for modulation: OFDM symbol• Adjustable guard periods : cyclic prefix used to dissipate multipath effect
• Symbol rate = f(channel bandwidth, carrier spacing - Distance between subcarriers)
© Forsk 2009 Slide 15 of 149Confidential – Do not share without prior permission
OFDM Frequency and Time Domains
1 OFDM symbol
Fre
qu
en
cy
Su
bca
rrie
rs
Symbols
Time
© Forsk 2009 Slide 16 of 149Confidential – Do not share without prior permission
Differences between FDM and OFDM
FDM (Frequency Division Multiplexing)
Carriers separated by guard bands low spectrum usage efficiency
More carriers more guard bands decrease in efficiency
Therefore, usually large carrier widths are used
Large carrier widths low symbol duration (f=(1/t)) more sensitive to time delays
© Forsk 2009 Slide 17 of 149Confidential – Do not share without prior permission
Differences between FDM and OFDM
OFDM (Orthogonal Frequency Division Multiplexing)
Narrowband orthogonal carriers negligible inter-carrier-interference (ICI)
Long symbol durations + cyclic prefix negligible inter-symbol-interference (ISI)
No ICI and ISI no intra-cell interference
Possibility to support less robust modulations like 64QAM, 16QAM, … for higher throughput
Centre point of subcarrier c intersects with subcarriers c-1 and c+1 at their 0 values
© Forsk 2009 Slide 18 of 149Confidential – Do not share without prior permission
Advanced OFDM : OFDMA
OFDMA : Orthogonal Frequency Division Multiple Access
OFDMEach user is allocated the full channel : capacity wasting
OFDMAEach user can be assigned only a part of the entire channel at a time
Ability to subdivide the subcarrier population : more than one user served at a time
Su
bch
ann
els
Su
bch
ann
els
Su
bch
ann
els
Su
bch
ann
els
© Forsk 2009 Slide 19 of 149Confidential – Do not share without prior permission
Benefits of OFDM/OFDMA
Negligible inter-carrier-interference (ICI)Thanks to orthogonal subcarriers which can be transmitted by the use of Fast Fourier Transform (equipment evolution)
Use of less robust modulation Increased data rate
Improved resilience (ISI)Sending data across parallel carriers lower rate/carrier
Fewer modulation symbols longer symbol duration• Better chance to correctly sample signal
Efficient usage of the spectrum
Better resistance to frequency selective fading channel
Multiple access (time and frequency multiplexing techniques)
© Forsk 2009 Slide 20 of 149Confidential – Do not share without prior permission
Multiplexing and Duplexing
Uses SOFDMA (same as WiMAX 802.16e) in DLSOFDMA: Scalable Orthogonal Frequency Division Multiple Access
Uses SC-FDMA in UL (an OFDM variant not much different from SOFDMA)SC-FDMA: Single-Carrier Frequency Division Multiple Access
Can be deployed in FDD and TDD
© Forsk 2009 Slide 21 of 149Confidential – Do not share without prior permission
Multiple Access Techniques
1g1g 2g2g
3g3g4g4g
© Forsk 2009 Slide 22 of 149Confidential – Do not share without prior permission
OFDM and OFDMA
Orthogonal Frequency Division Multiple AccessProvides resource allocation flexibility
Scalable OFDMAChannel bandwidth is scalable, i.e., can be adapted as needed
© Forsk 2009 Confidential – Do not share without prior permission Slide 23 of 149
3
5
10
15
20
Bandwidth (MHz)
1.4
LTE Channel Structure
OFDMA in DL and SC-FDMA in ULA channel is composed of more than 1 Frequency Block (FB)
• Equivalent of Subchannel in WiMAX• Fixed width = 180 kHz (LTE system level constant)• 1 Frequency Block over 1 slot = 1 Resource Block (RB) (Elementary unit assigned to 1 user)• Benefit of SC-FDMA: Low Peak-to-Average Power Ratio (PAPR) Easier UE Design
Each FB is composed of many Subcarriers• Two Subcarrier widths possible: 15 kHz, 7.5 kHz• 1 FB = 12 SCa of 15 kHz OR 24 SCa of 7.5 kHz• 7.5 kHz specified for MBMS/SFN services
• Narrow subcarrier width Longer symbol duration + Longer Cyclic Prefix = More resistant against multipath
© Forsk 2009 Confidential – Do not share without prior permission Slide 24 of 149
LTE Channel Structure
SpectrumAllocation
SubcarrierSpacing
SamplingFrequency
FFT SizeNumberof RBs
Number ofUsed Subcarriers
1.4 MHz
15 kHz(7.5 kHz
for MBMS)
1.92 MHz(1/2 x 3.84)
128 6 72 (73)
3 MHz3.84 MHz(1 x 3.84)
256 15 180 (181)
5 MHz7.68 MHz(2 x 3.84)
512 25 300 (301)
10 MHz15.36 MHz(4 x 3.84)
1024 50 600 (601)
15 MHz23.04 MHz(6 x 3.84)
1536 75 900 (901)
20 MHz30.72 MHz(8 x 3.84)
2048 100 1200 (1201)
© Forsk 2009 Slide 25 of 149Confidential – Do not share without prior permission
TDD and FDDSpecific frame structures for TDD and FDD
1 frame = 10 ms = 2 half-frames (TDD) = 10 subframes or TTI (each 1 ms) = 20 slots (each 0.5 ms)
1 slot (0.5 ms) = 6 or 7 symbol durations
Control channels transmitted on subframes 0 and 5 (always DL)
Two possible cyclic prefix durations: Normal or Extended (resp. 7 or 6 OFDM symbols per slot)
LTE Frame Structure
LTE Frame
10 ms
SF 0 SF 1 SF 9……………………………..
1 ms
Slot 0 Slot 1 Slot 2 Slot 3Slot 18…………………………….. Slot
19
0.5 ms
© Forsk 2009 Slide 26 of 149Confidential – Do not share without prior permission
LTE Frame Structure
FDD Frame
TDD Frame with (DwPTS, GP, and UpPTS as in TD-SCDMA)Full- and Half-frame switching point periodicity
Half-frame periodicity provides the same half-frame structure as a TD-SCDMA subframe
© Forsk 2009 Confidential – Do not share without prior permission Slide 27 of 149
FDD Frame = 10 ms
0 2 3 4 5 7 8 9
1 ms
61
Subframe
TDD Frame = 10 ms (with SPP = ½ Frame) Half frame = 5 ms
0 2 3 4 5 7 8 9
DwPTS UpPTSGP DwPTS UpPTSGP
1 msSubframe
TDD Frame = 10 ms (with SPP = Frame) Half frame = 5 ms
0 2 3 4 5 7 8 9
DwPTS UpPTSGP
6
1 msSubframe
eNode-B
Physical Channels
Primary-SCH
Secondary-SCH
Physical Downlink Shared Channel
Common Control Physical Channel
Physical Downlink Control Channel
Physical Random Access Channel
Physical Uplink Shared Channel
Physical Uplink Control Channel
HARQ feedbackCQI reporting
UL scheduling requestCQI reporting for MIMO
related feedback
Random access
Traffic
Slot/Frame synchronization &
Cell Id identification
Traffic, MBMSControl information
Paging
HARQ feedbackTransport format
UL scheduling grantResource allocation
© Forsk 2009 Slide 28 of 149Confidential – Do not share without prior permission
Control and Traffic Channels
BCCH PCCH CCCH DCCH DTCH MCCH MTCH
BCH PCH UL-SCHDL-SCH MCH RACH
PBCH PUSCHPDSCH PMCH PRACHPUCCH
Transport
Logical
Physical
DL TCH UL TCH
© Forsk 2009 Slide 29 of 149Confidential – Do not share without prior permission
OFDMA LTE Frame (DL)
Structure of a Resource BlockFrame structure of Type I, 1 antenna, ΔF = 15 kHz
• Standard frequency block
• Any frequency block within the centre 6 frequency blocks:
Legend:Downlink Reference Signals
PBCH
P-SCH
S-SCH
PDCCH / PHICH / PCFICH
DL-SCH
Subcarriers in a resource block are adjacent
RBs allocated to mobiles are not necessary adjacent Interference Coordination
© Forsk 2009 Slide 30 of 149Confidential – Do not share without prior permission
OFDMA LTE Frame (DL)
OFDMSymbol 0
OFDMSymbol 1
OFDMSymbol 3
OFDMSymbol 4
OFDMSymbol 5
OFDMSymbol 6
OFDMSymbol 2
Legend:
Downlink Reference signals
PBCH
P-SCH
S-SCH
PDCCH / PHICH / PCFICH
DL-SCH
P-SCH and S-SCH ~ Preamble in WiMAXDL Reference signals ~ Pilot subcarriers in WiMAX
1 subframe = 2 slots (1 ms)
1 frame = 10 subframes (10 ms)
SF 0 SF 1 SF 2 SF 3 SF 4 SF 5 SF 6 SF 7 SF 8 SF 9
7 OFDM symbols at normal CP per slot (0.5 ms)
0 1 2 3 4 5 6 0 1 2 3 4 5 6
© Forsk 2009 Slide 31 of 149Confidential – Do not share without prior permission
SC-FDMA LTE Frame (UL)
OFDMSymbol 0
OFDMSymbol 1
OFDMSymbol 3
OFDMSymbol 4
OFDMSymbol 5
OFDMSymbol 6
OFDMSymbol 2
Legend:
Uplink Demodulation Reference Signal
Uplink Sounding Reference Signal
PUCCH
Demodulation Reference Signal for PUCCH
1 subframe = 2 slots (1 ms)
1 frame = 10 subframes (10 ms)
SF 0 SF 1 SF 2 SF 3 SF 4 SF 5 SF 6 SF 7 SF 8 SF 9
7 OFDM symbols at normal CP per slot (0.5 ms)
0 1 2 3 4 5 6 0 1 2 3 4 5 6
© Forsk 2009 Slide 32 of 149Confidential – Do not share without prior permission
Cell Search/Synchronisation
eNode-B
72 subcarriers
Sub-carriers for data
SCH in 1.25 MHz/72 subcarriers
BCH in 1.25 MHz/72 subcarriers
1.4/3/5/10/15/20 MHz spectrum
1.25 MHz spectrum
BCH informationreception
UE SCH detection over a
1.4/3/5/10/15/20 MHz spectrum
Detect spectrum centre and 1.25 MHz
spectrum
SCH and BCH frequency reception
Data transmission on assigned spectrum provided by System
Information
SCH and BCH band
© Forsk 2009 Slide 33 of 149Confidential – Do not share without prior permission
Usual 1x3x1 and 1x3x3 allocations
Fractional Frequency Allocation: like segmentation in WiMAXPossibility to allocate 3 fractions of the a channel to 3 sectors of a site
Provides better spectrum usage and interference reduction
Frequency Planning
F1 F2 F3
Frequency
F1
F1 F1 F2F3
F1
F1
Seg 2 Seg 3Seg 1Seg1
Seg 3 Seg 2
Seg1
Seg 3 Seg 2
F1
F1 F1
© Forsk 2009 Slide 34 of 149Confidential – Do not share without prior permission
Handovers in LTE
Hard handover
Fast BS Selection
No soft handover specified for LTE
© Forsk 2009 Slide 35 of 149Confidential – Do not share without prior permission
MIMO Systems in LTE
Multiple Input Multiple Outputs (MIMO) systemsStations and user equipment can support MIMO systems
• Numbers of transmission and reception antenna ports at the transmitter and user equipment
Supported MIMO systems: • Transmit or Receive Diversity (Tx/Rx Div)
• More than one transmission antenna to send the same data• Improvement of CINR
• Single-user MIMO or spatial multiplexing (SM)• More than one transmission antenna to send different data streams on each antenna• Improvement of throughput for a given CINR
• Adaptive MIMO switch (AMS)• Technique to switch from SM to Tx/Rx Diversity as CINR conditions get worse than a given
threshold
• Multi-user MIMO or collaborative MIMO• Multiplexing of several users with good enough radio conditions• More than one cell reception antenna to receive transmissions from several users over the
same frequency-time allocation (UL only)• Can be used with single-antenna user equipment• Improvement of UL capacity in terms of number of connected users
© Forsk 2009 Slide 36 of 149Confidential – Do not share without prior permission
Training Program
1. LTE Concepts
2. LTE Planning Overview
3. Modelling an LTE Network
4. LTE Predictions
5. MIMO Modelling
6. Neighbour Allocation
7. Automatic Resource Planning
8. Frequency Plan Analysis
9. Monte-Carlo Based Simulations
10. Using Drive Tests
11. Terminology and Concepts
© Forsk 2009 Slide 37 of 149Confidential – Do not share without prior permission
2. LTE Planning Overview
LTE features supported in Atoll
LTE workflow in Atoll
© Forsk 2009 Slide 38 of 149Confidential – Do not share without prior permission
LTE Features supported in Atoll
Supports Evolved UTRA (3GPP Release 8 LTE) NetworksVarious frequency bands
Scalable channel bandwidths
Resource blocks per channel and sampling frequencies
Support of TDD and FDD frame structures
Half-frame/full-frame switching point periodicities for TDD
Normal and extended cyclic prefixes
Downlink and uplink control channels and overheads• Downlink and uplink reference signals, P-SCH, S-SCH, PBCH, PDCCH, PUCCH, etc.
Physical cell IDs
Possibility of fixed subscriber database for fixed applications
Support of directional CPE antennas© Forsk 2009 Slide 39 of 149Confidential – Do not share without prior permission
LTE Features supported in Atoll
Supports Evolved UTRA (3GPP Release 8 LTE) NetworksSignal level based coverage planning
CINR based coverage planning
Network capacity analysis using Monte Carlo simulations
Scheduling and resource allocation in two-dimensional frames
Multiple Input Multiple Output (MIMO) systems• Transmit and Receive Diversity• Single-User MIMO or spatial multiplexing • Adaptive MIMO Switch (AMS)• Modelling of Multi-User MIMO (collaborative MIMO – UL only)
Tools for resource allocation• Automatic allocation of neighbours and physical cell Ids• Automatic allocation of frequencies (AFP) (Optional)
Network verification possible using test mobile data
© Forsk 2009 Slide 40 of 149Confidential – Do not share without prior permission
LTE Workflow in AtollLTE Workflow in Atoll
Open an existing project or create a new one
Prediction study reports
Traffic maps
Network configuration- Add network elements- Change parameters
User-defined values
Automatic or manual neighbour allocation
Basic predictions(Best server, signal level)
Monte-Carlo simulations
Signal quality and throughput predictions
Cell load conditions
Subscriber lists
And/or
Frequency plan analysis
Automatic or manual frequency planning
Automatic or manual physical cell ID planning
© Forsk 2009 Slide 41 of 149Confidential – Do not share without prior permission
Training Program
1. LTE Concepts
2. LTE Planning Overview
3. Modelling an LTE Network
4. LTE Predictions
5. MIMO Modelling
6. Neighbour Allocation
7. Automatic Resource Planning
8. Frequency Plan Analysis
9. Monte-Carlo Based Simulations
10. Using Drive Tests
11. Terminology and Concepts
© Forsk 2009 Slide 42 of 149Confidential – Do not share without prior permission
3. Modelling an LTE Network
Frequency bands
LTE Frame structure settings
Transmitter parameters
Cell parameters
© Forsk 2009 Confidential – Do not share without prior permission Slide 43 of 149
Frequency bandsAtoll can model multi-band networks within the same document
TDD (Time Division Duplexing) or FDD (Frequency Division Duplexing)
One frequency band assigned to each cell
Frequency Bands
© Forsk 2009 Slide 44 of 149Confidential – Do not share without prior permission
Transmitter folder global parameters
System-level constants (Hard-coded)• Width of a resource block (180 kHz)• Frame duration (10 ms)
Other control channel overheads defined by 3GPP (calculated based on 3GPP specs)• Reference signals, P-SCH, S-SCH, PBCH, etc.
LTE Frame structure settings
Number of SD for Physical Downlink Control Channel
(0,1,2 or 3) carrying DL and UL Resource
allocation information
Normal (default) or extended cyclic prefix (No. of SD per slot)
e.g.: at 15 kHz, 7 SD/slot (normal) or 6 SD/slot
(extended)
Average number of resource blocks for Physical Uplink Control Channel (top
and bottom of frame transmitted every 2 slots)
TDD option only : Switch from DL to UL every half frame (default) or every
frame
© Forsk 2009 Slide 45 of 149Confidential – Do not share without prior permission
Transmitter Parameters
Equipment specifications
DL and UL total losses, noise figure
Cells: (Tx-carrier) pairsSpecifications of carriers in a
transmitter
MIMO (Multiple Input Multiple Output systems)
reception and transmission settings
© Forsk 2009 Slide 46 of 149Confidential – Do not share without prior permission
Cell Parameters
Inputs of the neighbour allocation algorithm
Neighbour list
UL/DL traffic loads*
Cell activity
Power and energy offsets from computed
reference signal
Cell’s frequency band
Channel number in the frequency band (and
allocation status)
LTE equipment used for bearer selection/quality
indicator studies/MIMO gains
UL noise rise due to surrounding mobiles*
Maximum simultaneous users supported by the cell*
Physical Cell ID ( and allocation status)
Frame configuration (TDD only)
Threshold to switch from SM to Tx/Rx Div or
for using MU-MIMO
Reference signal quality threshold used as cell
coverage limit
Scheduler used for bearer selection and resource allocation
Cell order used for carrier selection
Resource allocation min reuse distance
Cell capacity gain in case of MU-MIMO
Effect of external sources of interferences
Max UL and DL traffic loads to be respected
during simulations
* User-defined or simulation output
UL and DL MIMO support (Tx/Rx Div, SU-MIMO/SM,
AMS and/or MU-MIMO)
© Forsk 2009 Slide 47 of 149Confidential – Do not share without prior permission
Training Program
1. LTE Concepts
2. LTE Planning Overview
3. Modelling an LTE Network
4. LTE Predictions
5. MIMO Modelling
6. Neighbour Allocation
7. Automatic Resource Planning
8. Frequency Plan Analysis
9. Monte-Carlo Based Simulations
10. Using Drive Tests
11. Terminology and Concepts
© Forsk 2009 Slide 48 of 149Confidential – Do not share without prior permission
4. LTE Predictions
Introduction
Parameters used in predictions
Prediction settings
Fast link adaptation modelling
Coverage prediction examples
Point analysis studies
© Forsk 2009 Slide 49 of 149Confidential – Do not share without prior permission
Introduction
Coverage predictionsGeneral studies based on downlink reference signal levels
• Best server plot based on downlink reference signal levels• Multiple server coverage based on downlink reference signal levels• Reference signal signal level plots• Reference signal CNR plots
LTE UL and DL specific studies• SCH/PBCH, PDSCH, and PUSCH signal level plots• SCH/PBCH, PDSCH, and PUSCH CNR plots• Quality studies (reference signal, SCH/PBCH, PDSCH, and PUSCH CINR and interference plots)• Best bearer plots based on PDSCH and PUSCH CINR levels• Throughput and cell capacity per pixel plots based on PDSCH and PUSCH CINR levels
• Peak RLC, effective RLC, and application throughputs• Peak RLC, effective RLC, and application cell capacities• Peak RLC, effective RLC, and application aggregate cell throughputs
Point predictions
© Forsk 2009 Slide 50 of 149Confidential – Do not share without prior permission
Introduction
Principles of the studies based on traffic
Study calculated for
• Given load conditions• UL noise rise• DL traffic load
• A non-interfering user with• A service• A mobility• A terminal type with a directive antenna (oriented towards the serving cell)
© Forsk 2009 Slide 51 of 149Confidential – Do not share without prior permission
Load Conditions
Load conditions are defined in the cells table
Values taken into consideration in predictions for each cell
© Forsk 2009 Slide 52 of 149Confidential – Do not share without prior permission
Service Properties
Parameters used in predictionsHighest bearers in UL and DL
Body loss
Application throughput parameters
© Forsk 2009 Slide 53 of 149Confidential – Do not share without prior permission
LTE Bearer Properties
Support for multiple modulation and coding schemes (MCS)User-selectable modulations (QPSK, 16QAM, and 64QAM)
User-definable coding rates (e.g. 1/2, 2/3, 3/4, etc.)
User-definable bearer efficiencies (useful bits per resource element)• Used for channel throughput evaluation
© Forsk 2009 Slide 54 of 149Confidential – Do not share without prior permission
LTE Bearer Properties
Link adaptation in LTE
© Forsk 2009 Slide 55 of 149Confidential – Do not share without prior permission
Mobility Properties
Parameters used in predictionsMapping between mobilities and thresholds in bearer and quality indicator determination (as radio conditions depend on user speed).
© Forsk 2009 Slide 56 of 149Confidential – Do not share without prior permission
Terminal Properties
Parameters used in predictionsReception equipment
Antenna settings (incl. MIMO support)
Maximum terminal power
Gain and losses
Noise figure
Support of MIMO
Number of Antenna ports in UL and DL in case of MIMO
support
© Forsk 2009 Slide 57 of 149Confidential – Do not share without prior permission
Prediction Settings
Coverage prediction plots
Do not require Monte-Carlo simulations or subscriber lists
Reference signal, SCH/PBCH, PDSCH, and PUSCH signal level plots• Best server plot
• Coverage by signal level
• Multiple server coverage
Preamble signal quality based coverage predictions• Selection of a mobility, a service, a terminal (possibly directional antenna oriented towards the serving
cell)
• Reference signal, SCH/PBCH, PDSCH, and PUSCH CNR plots
© Forsk 2009 Slide 58 of 149Confidential – Do not share without prior permission
Prediction Settings
Coverage prediction plots
Traffic channel CINR based coverage predictions• Based on user-defined cell loads or on Monte-Carlo simulation results
• Selection of a mobility, a service, a terminal (possibly directional antenna oriented towards the serving cell)
• Reference signal, SCH/PBCH, PDSCH, and PUSCH CINR and interference plots
• Best bearer plots based on PDSCH and PUSCH CINR levels
• Throughput and cell capacity per pixel plots based on PDSCH and PUSCH CINR levels• Peak RLC, effective RLC, and application throughputs• Peak RLC, effective RLC, and application cell capacities• Peak RLC, effective RLC, and application aggregate cell throughputs
© Forsk 2009 Slide 59 of 149Confidential – Do not share without prior permission
Fast Link Adaptation Modelling
Atoll determines, on each pixel, the highest bearer that each user can obtainNo soft handover
Connection to the best server in term of reference signal level (C)
Bearer chosen according to the radio conditions (PDSCH and PUSCH CINR levels)
Process : prediction done via look-up tables
Reference signal quality evaluation (C)
Best server and service area determination (C/N)
PDSCH and PUSCH CINR calculation
Highest bearer determination limited by the
service settings
Peak RLC, effective RLC, and application throughput
calculation
Quality indicator (BER, BLER)
© Forsk 2009 Slide 60 of 149Confidential – Do not share without prior permission
Interference Estimation
Atoll calculates PDSCH and PUSCH CINR according to:The victim traffic (PUSCH or PDSCH) power
The interfering signals impacted by:• The interferer powers• The path loss from the interferer to the victim• Antenna gain• Losses from interferer (incl. Shadowing effect and indoor losses)
The interference reduction due to the co and adjacent channel overlap between the studied and the interfering base stations
The interference reduction factor due to interfering base station’s traffic load
© Forsk 2009 Slide 61 of 149Confidential – Do not share without prior permission
Bearer Selection
When PDSCH and PUSCH CINR are evaluated, the bearer is selected according to:The LTE reception equipment defined at reception (cell for UL, terminal for DL)
The CINR threshold to access each bearer
Scheduler parameters of the serving cell• Bearer selection criterion• The uplink bandwidth allocation target
The highest possible bearer according to the service settings
© Forsk 2009 Slide 62 of 149Confidential – Do not share without prior permission
Bearer Selection
Scheduler settings for bearer determination
Bearer selection criterion: • Bearer index: selection of the highest bearer index
• Peak RLC throughput: selection of the highest peak RLC throughput
• Effective RLC throughput: selection of the highest effective RLC throughput
Uplink bandwidth allocation target:• Full bandwidth: use of all the frequency blocks
• Maintain connection: number of frequency blocks reduced one by one to increase the PUSCH CINR so that the mobile is able to get at least the lowest
bearer (as defined by the bearer selection criterion)• Best bearer: number of frequency blocks reduced to increase the PUSCH
CINR so that the mobile is able to get the best bearer available (as defined by the bearer selection criterion)
© Forsk 2009 Slide 63 of 149Confidential – Do not share without prior permission
Throughput Estimation
When the bearer is selected, the channel throughput is calculated according to:The channel bandwidth and the sampling frequency
The frame definition considering hard coded parameters and user-defined ones (global parameters tab or the Transmitter folder property box).
The cyclic prefix ratio
The bearer efficiency defined in the selected bearer
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Quality Indicator Estimation
When the bearer is selected, the quality indicator (BER or BLER) is obtained according to:The graphs defined in the quality graph tab of the receiver equipment
The selected bearer
The calculated PDSCH and PUSCH CINRs
The terminal mobility (optionally)
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Prediction Examples (General Studies)
Coverage by signal level
(Based on reference signal power)
Number of servers
(Based on reference signal power)
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Prediction Examples (Dedicated Studies)
Coverage by PDSCH CINR
(Isotropic receiver antenna)
Coverage by PDSCH CINR
(Directional receiver antenna)
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Prediction Examples (Dedicated Studies)
Coverage by PUSCH CINR
(Isotropic receiver antenna)
Coverage by PUSCH CINR
(Directional receiver antenna)
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Point Analysis Tool
Radio reception level at a given point : Reception tab
Select the reception tab in the point analysis window
In the tool bar, click
Define receiver settings
Display preamble signal levels
Reference signal levels
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Point Analysis Tool
Radio reception diagnosis at a given point : Signal Analysis tab
Choice of UL&DL load conditions : if (cells table) is selected
Analysis based on DL load and UL noise rise from cells table
Definition of a user-definable “probe" receiver, indoor or
not
Received reference signals (best server on
the top)
Analysis detail on reference signals,
PDSCH and PUSCH
SCH/PBCH, reference signals,
PDSCH and PUSCH
availability (or not)
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Training Program
1. LTE Concepts
2. LTE Planning Overview
3. Modelling an LTE Network
4. LTE Predictions
5. MIMO Modelling
6. Neighbour Allocation
7. Automatic Resource Planning
8. Frequency Plan Analysis
9. Monte-Carlo Based Simulations
10. Using Drive Tests
11. Terminology and Concepts
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5. MIMO Modelling
Overview
MIMO settings in Atoll
MIMO Modelling in computations
Predictions examples
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MIMO Modelling Overview
Base stations and user equipment support MIMO systemsGains graphs available in reception equipment
Numbers of transmission and reception antenna ports at base station and terminal
Antenna diversity modes in Atoll LTEMultiple Input Multiple Outputs (MIMO) systems
• Transmit/Receive Diversity (also called Space-Time Coding (STC) or Matrix A MIMO in other standards)• More than one transmission antenna to send the same data• Improvement of CINR Higher bearer Higher throughput• Usually used in coverage areas with bad CINR conditions
• Single-User MIMO (SU-MIMO) or Spatial Multiplexing (SM) (also called Matrix B MIMO in other standards)• More than one transmission antenna to send different data streams on each antenna• Improvement of throughput for a given CINR• Usually used in coverage areas with good CINR conditions
• Adaptive MIMO Switch (AMS)• Technique to switch from SM to Tx/Rx Diversity as CINR conditions get worse than a given
threshold
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MIMO Modelling Overview
Antenna diversity modes in Atoll LTE (Cont’d)Multiple Input Multiple Outputs (MIMO) systems
• Multi-User MIMO or collaborative MIMO• Multiplexing of several users with good enough radio conditions• More than one cell reception antenna to receive transmissions from several users over the
same frequency-time allocation (UL only)• Can be used with single-antenna user equipment• Improvement of UL capacity in terms of number of connected users
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MIMO Settings in Transmitters
MIMO (Multiple Input Multiple Output systems)
reception and transmission settings
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MIMO Settings in Cells
Definition of the MIMO support type (STTD/MRC
(Transmit or Receive Diversity), SU-MIMO (SM),
AMS or MU-MIMO – UL Only)
Minimum reference signal C/N used as :
- threshold to switch from SU-MIMO to Tx/Rx Diversity
- Minimum required for using MU-MIMO
Uplink capacity gain due to MU-MIMO. The cell capacity is multiplied by this gain at pixels where MU-MIMO is
used
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MIMO Settings in Terminals
Support of MIMO
Number of Antenna ports in UL and DL in case of MIMO support
Reception equipment defining SU-MIMO and
diversity gains
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Transmit and Receive Diversity Settings
Diversity gain depending on the MIMO configuration
Additional Diversity gain per clutter class (DL and UL)
Sum of the gains applied on PDSCH/PUSCH CINR© Forsk 2009 Slide 78 of 149Confidential – Do not share without prior permission
SU-MIMO Settings
Maximum possible gain in channel capacity
SU-MIMO gain factor per clutter class
MIMO throughput = SISO throughput (1 + SU-MIMO gain factor (max MIMO gain – 1))© Forsk 2009 Slide 79 of 149Confidential – Do not share without prior permission
MIMO Modelling in Computations
Predictions and simulationsOn each pixel, a receiver is connected to its best server (in term of reference signal C/N)
MIMO is possible if :• MIMO settings are defined in the LTE equipment selected at the cell – for UL – (or terminal – for DL –)
level
• The support of any MIMO mode (Tx/Rx diversity, SM, AMS, SU-MIMO) is defined for to the serving cell
• MIMO is supported by the user’s terminal
• The calculated reference signal C/N exceeds the reference signal C/N threshold
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Prediction Examples (MIMO Effect)
Coverage prediction examples (MIMO system)
Coverage by DL CINR
(Without MIMO)
Coverage by DL CINR
(MIMO with 2*2 antenna)
CINR improved for low values (due to Tx/Rx
diversity)
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Training Program
1. LTE Concepts
2. LTE Planning Overview
3. Modelling an LTE Network
4. LTE Predictions
5. MIMO Modelling
6. Neighbour Allocation
7. Automatic Resource Planning
8. Frequency Plan Analysis
9. Monte-Carlo Based Simulations
10. Using Drive Tests
11. Terminology and Concepts
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6. Neighbour Allocation
Importing existing neighbour relationships
Neighbour automatic allocation
Neighbour graphical display
Modifying neighbour relationships manually
Exporting neighbour relationships
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Importing Existing Neighbour Relationships
Possibility to copy/paste or to import a list of neighboursIntra-carrier and inter-carrier neighbours are mixed in the same table
PrerequisitesA text file with at least 2 columns
• Source cells and neighbour cells• Relationships must be defined between atoll format cell names
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Importing Existing Neighbour Relationships
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Neighbour Automatic Allocation (1/4)
Possibility to define neighbourhood constraints to be considered during the automatic neighbour allocation
Allocation parametersMaximum number of neighbours
• Global value for all the transmitters or value specified for each transmitter
Maximum inter-site distance
Allocation strategy based on the overlapping of cell coverage
List of neighbourhood relationships you may force or forbid
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Neighbour Automatic Allocation (2/4)
Coverage conditions
Overlapping criterion
Calculation options
Do not select the option if you want to keep existing
neighbours
Start allocation
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Neighbour Automatic Allocation (3/4)
Overlapping criterion % min covered area is defined by the formula : (SA ∩ SB) / SA where :- SA is the coverage area of a restricted by ho start and ho end- SB is the best server area of cell B
Best reference signal level cell B (candidate)
Best reference signal level cell A (reference)
Cell A
Cell B
Reference signal threshold (from reference signal
quality threshold)
Handover start
Handover end
Best server area
Best server area
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Neighbour Automatic Allocation (4/4)
Allocation resultSorted list of neighbours with allocation reasons and importance value (0-1)
Commit selected neighbours only
Allocation results
Sort and filtering tools
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Neighbour Graphical Display
Display of neighbourhood links on the map
Calculate a “coverage by transmitter” and display it on the map
Select the icon in the toolbar and click a transmitter on the map
Inwards link: site23_1(0) is neighbour of site22_0(0)
Symmetric link: site17_1(0) is neighbour of site23_1(0) and
vice-versa
Outwards link: site27_0(0) is neighbour of site23_1(0)
Neighbourhood relationships of site23_1(0)
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Neighbour Graphical Display
Possibility to display neighbour characteristics on the mapCalculate a “coverage by transmitter” and display it on the map
Display neighbour relationships of the desired transmitter
Click the icon from the toolbar
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Modifying Neighbour Relationships Manually
Possibility to add/remove neighbour relationships on the map using the ctrl and shift shortcuts
For intra-carrier neighbourhood links only
Possibility to add/remove neighbours in the cell property dialogue Neighbour list of site5_2(0)
List of transmitters within a 30 km radius from the selected one (sorted in a
ascending inter-site distance order)© Forsk 2009 Slide 92 of 149Confidential – Do not share without prior permission
Exporting Neighbour Relationships
Possibility to copy/paste or to export the list of neighbours
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Training Program
1. LTE Concepts
2. LTE Planning Overview
3. Modelling an LTE Network
4. LTE Predictions
5. MIMO Modelling
6. Neighbour Allocation
7. Automatic Resource Planning
8. Frequency Plan Analysis
9. Monte-Carlo Based Simulations
10. Using Drive Tests
11. Terminology and Concepts
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7. Automatic Resource Planning
Automatic resource planning overview
Automatic physical cell ID allocation process
Automatic frequency allocation process
Frequency allocation examples
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Automatic Resource Planning Overview
Automatic Physical Cell ID PlanningBased on neighbour and distance relations
Allocation of S-SCH IDs and P-SCH IDs
Automatic Resource Planning (Optional)Based on interference matrices, neighbour, distance relations
Possibility to lock frequencies for cells
Can work with more than one frequency band in the same document
Can also allocate physical cell IDs taking interference matrices into account
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Automatic Physical Cell ID Allocation Process
Physical Cell ID definition : (physical cell ID of the cell)Physical cell IDs defined in the 3GPP specifications.
Integer value from 0 to 503• 504 unique physical-layer cell identities.• Grouped in 168 unique cell ID groups (called S-SCH IDs in Atoll), each group containing 3 unique
identities (called P-SCH IDs in Atoll)• S-SCH ID belongs to [0,167] and P-SCH ID is either 0, 1 or 2.• Each cell’s reference signals transmit a pseudo-random sequence corresponding to the physical cell
ID of the cell.
Physical Cell ID allocation to cellsGoals
• Avoid using the same pseudo-random sequence in nearby cells• Can cause problems in cell search and selection
• Avoid using the same P-SCH ID to nearby cells• Can cause a lot of interference
• Use preferably the same S-SCH ID to cells of the same site• Can help in measurements and handover procedures
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Automatic Physical Cell ID Allocation Process
Automatic Physical Cell ID allocation in AtollBased on an iterative cost-based algorithm
Different physical Cell ID allocation plans are tried and a cost calculated for each
The best physical Cell ID allocation plan is the one with the lowest cost
The cost is calculated for cells with the following relations• Neighbours (optional)• Distance between cells < min reuse distance (optional)• Frequency plan
Relations between cells can have different importance in the final cost• The importance of neighbour relation is calculated during the automatic neighbour allocation • The importance of the relation based on the distance between cells (weighted by the antenna
azimuths)
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Automatic Physical Cell ID Allocation Process
Automatic physical Cell ID allocation prerequisitesFrequency plan
• A channel manually assigned to each cell
Neighbour plan• Manually or automatically obtained• Importance values
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Automatic Physical Cell ID Allocation Process
Automatic physical Cell ID allocation process
Commit Physical Cell Ids to cells
S-SCH ID allocation strategy
Allocation cost constraints
Allocated Physical Cell Ids, P-SCH IDs and S-SCH IDs
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Automatic Frequency Allocation Process
Optimization of the frequency allocation in a network
The optimum frequency plan minimizes the interference in the network
Compliance with given constraintsExcluded channels
Interferences
Reuse distance
Neighbour relations
…
The algorithm starts with the current frequency plan as the initial state
Frequencies can be locked for cells
The AFP can work with more than one frequency band in the same document
Channels can be excluded
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Automatic Frequency Allocation Process
Based on an iterative cost-based algorithm
Different frequency allocation plans are tried and a cost calculated for each
The best frequency allocation plan is the one with the lowest global cost
The cost is calculated for cells thanks toInterference matrices
• Probabilities of interference in co- and adjacent channel cases• A probability calculated for each case for each interfered-interfering cell pair
Distance relation• For distance between cells < min reuse distance• Takes into account distance, orientation of cells
Neighbours• Takes into account importance of neighbour relation (adjacent, co-site)
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Automatic Frequency Allocation Process
Automatic resource allocation process
Commit channels to cells
Interference matrices calculation (to run before frequency
allocation)
Allocated channels
Possibility to allocate Physical Cell IDs or
frequencies
Allocation constraints
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Automatic Frequency Allocation Process
Interference matrix calculationFor each cell pair, interference probability for co and adjacent channel cases
Interference probability is the ratio between• Interfered surface area within the best server coverage area of the studied cell• Best server coverage area of the studied cell
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Frequency Allocation Examples
Automatic frequency allocation in Atoll (example)Same channel all over
Reference Signal C/(I+N) Level (DL) (dB) >=30 0.0048Reference Signal C/(I+N) Level (DL) (dB) >=25 0.084Reference Signal C/(I+N) Level (DL) (dB) >=20 1.1228Reference Signal C/(I+N) Level (DL) (dB) >=15 5.8348Reference Signal C/(I+N) Level (DL) (dB) >=10 17.4132Reference Signal C/(I+N) Level (DL) (dB) >=5 40.244Reference Signal C/(I+N) Level (DL) (dB) >=0 77.7116Reference Signal C/(I+N) Level (DL) (dB) >=-5 134.9424Reference Signal C/(I+N) Level (DL) (dB) >=-10 160.302Reference Signal C/(I+N) Level (DL) (dB) >=-15 161.0816Reference Signal C/(I+N) Level (DL) (dB) >=-20 161.0816
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Automatic frequency allocation in Atoll (example)Manual allocation with 3 channels
Reference Signal C/(I+N) Level (DL) (dB) >=30 1.308Reference Signal C/(I+N) Level (DL) (dB) >=25 5.9396Reference Signal C/(I+N) Level (DL) (dB) >=20 17.3372Reference Signal C/(I+N) Level (DL) (dB) >=15 37.472Reference Signal C/(I+N) Level (DL) (dB) >=10 65.39Reference Signal C/(I+N) Level (DL) (dB) >=5 99.5252Reference Signal C/(I+N) Level (DL) (dB) >=0 132.9688Reference Signal C/(I+N) Level (DL) (dB) >=-5 157.2608Reference Signal C/(I+N) Level (DL) (dB) >=-10 161.0736Reference Signal C/(I+N) Level (DL) (dB) >=-15 161.0816Reference Signal C/(I+N) Level (DL) (dB) >=-20 161.0816
Frequency Allocation Examples
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Automatic frequency allocation in Atoll (example)Automatic allocation with 3 channels
Reference Signal C/(I+N) Level (DL) (dB) >=30 0.4784Reference Signal C/(I+N) Level (DL) (dB) >=25 2.7224Reference Signal C/(I+N) Level (DL) (dB) >=20 9.452Reference Signal C/(I+N) Level (DL) (dB) >=15 24.0344Reference Signal C/(I+N) Level (DL) (dB) >=10 48.532Reference Signal C/(I+N) Level (DL) (dB) >=5 81.5268Reference Signal C/(I+N) Level (DL) (dB) >=0 119.1992Reference Signal C/(I+N) Level (DL) (dB) >=-5 155.772Reference Signal C/(I+N) Level (DL) (dB) >=-10 161.074Reference Signal C/(I+N) Level (DL) (dB) >=-15 161.0816Reference Signal C/(I+N) Level (DL) (dB) >=-20 161.0816
Frequency Allocation Examples
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Automatic frequency allocation in Atoll (example)Manual allocation with 6 channels
Reference Signal C/(I+N) Level (DL) (dB) >=30 4.6172Reference Signal C/(I+N) Level (DL) (dB) >=25 13.6912Reference Signal C/(I+N) Level (DL) (dB) >=20 30.2844Reference Signal C/(I+N) Level (DL) (dB) >=15 55.658Reference Signal C/(I+N) Level (DL) (dB) >=10 87.18Reference Signal C/(I+N) Level (DL) (dB) >=5 120.9552Reference Signal C/(I+N) Level (DL) (dB) >=0 147.5192Reference Signal C/(I+N) Level (DL) (dB) >=-5 160.1648Reference Signal C/(I+N) Level (DL) (dB) >=-10 161.0808Reference Signal C/(I+N) Level (DL) (dB) >=-15 161.0816Reference Signal C/(I+N) Level (DL) (dB) >=-20 161.0816
Frequency Allocation Examples
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Automatic frequency allocation in Atoll (example)Automatic allocation with 6 channels
Reference Signal C/(I+N) Level (DL) (dB) >=30 3.4068Reference Signal C/(I+N) Level (DL) (dB) >=25 10.7292Reference Signal C/(I+N) Level (DL) (dB) >=20 24.9896Reference Signal C/(I+N) Level (DL) (dB) >=15 48.002Reference Signal C/(I+N) Level (DL) (dB) >=10 80.042Reference Signal C/(I+N) Level (DL) (dB) >=5 114.3036Reference Signal C/(I+N) Level (DL) (dB) >=0 142.5768Reference Signal C/(I+N) Level (DL) (dB) >=-5 159.694Reference Signal C/(I+N) Level (DL) (dB) >=-10 161.0812Reference Signal C/(I+N) Level (DL) (dB) >=-15 161.0816Reference Signal C/(I+N) Level (DL) (dB) >=-20 161.0816
Frequency Allocation Examples
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Training Program
1. LTE Concepts
2. LTE Planning Overview
3. Modelling an LTE Network
4. LTE Predictions
5. MIMO Modelling
6. Neighbour Allocation
7. Automatic Resource Planning
8. Frequency Plan Analysis
9. Monte-Carlo Based Simulations
10. Using Drive Tests
11. Terminology and Concepts
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8. Frequency Plan Analysis
Channel and Physical Cell ID search tools
Physical Cell ID allocation audit
Physical Cell ID histograms
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Search Tool Overview
Tool to visualise channel and P-SCH ID reuse on the map
Possibility to find cells which are assigned a given :• Frequency band + channel• Physical Cell ID • P-SCH ID• S-SCH ID
Way to use this tool
Create and calculate a coverage by transmitter with a colour display by transmitter
Open the search tool available in the view menu
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Channel Search Tool
Channel reuse on the map
Colours given to transmitters• Red : co-channel transmitters
• Yellow : multi-adjacent channel (-1 and +1) transmitters
• Green : adjacent channel (-1) transmitters• Blue : adjacent channel (+1) transmitters
• Grey : other transmitters
Frequency band and Channel number
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Physical Cell ID Search Tool
Physical Cell ID, P-SCH ID and S-SCH ID reuse on the map
Colours given to transmitters• Red or grey: if the transmitters carries or not the specified resource value (Physical Cell ID,
P-SCH ID or S-SCH ID)
Resource type Resource value
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Physical Cell ID Allocation Audit
Verification of the allocation inconsistenciesRespect of the reuse distance
Respect of neighbourhood constraints
If the Physical Cell ID allocation strategy is respected
Inconsistencies are displayed in the default text editor
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Physical Cell ID Histograms
View of the Physical Cell ID distribution
Dynamic pointer
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Training Program
1. LTE Concepts
2. LTE Planning Overview
3. Modelling an LTE Network
4. LTE Predictions
5. MIMO Modelling
6. Neighbour Allocation
7. Automatic Resource Planning
8. Frequency Plan Analysis
9. Monte-Carlo Based Simulations
10. Using Drive Tests
11. Terminology and Concepts
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9. Monte-Carlo Based Simulations
Simulation process
Simulation creation
Scheduling in simulations
Simulation results
Analysis of simulations
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Simulation Process
What’s a simulation in Atoll?
Distribution of users at a given moment (= snapshot)
Based on subscriber lists
Suitable for a fixed wireless access application
Based on traffic maps
Similar to UMTS/CDMA/WiMAX simulation process
Can be used for a fixed application (statistical user-list modelling)
Can be used for a mobile application (Monte-Carlo distribution of mobile users)
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Simulation Process
Requirement: subscriber list and/or traffic map(s)
The user distribution is generated using a Monte-Carlo algorithm
Based on traffic database and subscriber list/traffic map(s)
Weighted by a Poisson distribution
Each user is assigned
A service, a mobility type, a terminal and an activity status by random trial• According to a probability law using traffic database
A geographic position in the traffic zone by random trial• According to the clutter weighting and indoor ratio (user location is the same as subscriber location if
the simulation is based on a subscriber list)
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Simulation Creation
Number of simulations to run for the current
session
Optional growing factor on the selected traffic map(s)
Selection of traffic map(s) as traffic input
Selection of subscriber list(s) as traffic input (dedicated to fixed wireless access application)
Load constraints to respect during simulations (global
value or value per cell)
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Scheduling in Simulations
Scheduling and radio resource managementFiltering of mobiles up to cell capacity limits (max UL and DL loads)
Different schedulers available:• Max C/I• Proportional Demand• Proportional Fair
First pass• Resource allocation for the minimum throughput demands depending on the service priorities of the
users (priority field in services)
Second pass• Distribution of the remaining resources between users according to the schedulers defined in each cell
in order to reach the max throughput demand
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Simulation Results (1)
Analysis provided over the focus zone
Main simulation results includePer cell
• UL and DL traffic loads• UL noise rise• UL and DL aggregate cell throughputs• Traffic input and connection statistics• …
Per mobile• Serving transmitter and cell• Azimuth and tilt (towards the serving cell)• Reference signal, SCH/PBCH, PDSCH, and PUSCH signal levels• Reference signal, SCH/PBCH, PDSCH, and PUSCH CINR and interference levels• Best bearers based on PDSCH and PUSCH CINR levels• Cell throughputs, cell capacities, and user throughputs PDSCH and PUSCH CINR levels• Connection status and rejection cause• …
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Simulation Results (2)
Analysis provided over the focus zone
5 tabs : statistics, sites, cells, mobiles, initial conditions
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Simulation Results (3)
Writes the UL/DL traffic loads and the UL noise rise into the
cells table
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Simulation Results (4)
Display the users (terminals) on the map depending on the connection
status
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Analysis of Simulations
Calculation of LTE prediction studies based on simulations
Analysis of a single simulation
Average analysis of all the simulations in a group
Prediction based on the results of the simulation (DL load, UL noise rise, etc)
Prediction based on the average of simulations in the group (average DL load,
and average UL noise rise)
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Training Program
1. LTE Concepts
2. LTE Planning Overview
3. Modelling an LTE Network
4. LTE Predictions
5. MIMO Modelling
6. Neighbour Allocation
7. Automatic Resource Planning
8. Frequency Plan Analysis
9. Monte-Carlo Based Simulations
10. Using Drive Tests
11. Terminology and Concepts
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10. Using Drive Tests
Import of test mobile data path
Drive test management
Drive test graphic analysis
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Import of Test Mobile Data Paths
OverviewMeasurement path related to a serving cell and its neighbours
Check and improve the network quality
ImportSupported files
• Any ASCII text file (with tab, semi-colon or blank character as separator)• TEMS FICS-planet export (*.Pln)• TEMS text export (*.Fmt)
Procedure• Standard import as in excel• Mandatory information
• Position of measurement points• Physical Cell ID
• You can import any additional information related to measurement points• Definition and storage of import configurations• Multiple import
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Drive Tests Managements
TableList of all the measurement points with their attributes and additional information
Standard content management and tools (filters, copy-paste, etc...)
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Drive Tests Managements
Management of measurement path points
Option of extracting a field related to a specific transmitter along a path
Option of creating as many CW measurement paths as the number of involved transmitters along the path. These data can be used to calibrate any propagation model
Creation of any prediction on the transmitters measured
along the path
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Drive Tests Managements
Management of measurement path points
Filter per
type(s) of
clutter
Advanced filter on additional survey data
Permanent deletion of out-of-filter points
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Drive Tests Managements
Management of measurement path points
Option of preparing additional prediction studies along the path using the existing
transmitter parameters (antennas, propagation models, etc…)
List of defined studies in the measurement
table
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Drive Tests Managements
Management of measurement path points
Using the Atoll display dialog, you can display the points according to any data
contained in the measurement table
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Drive Tests Graphic Analysis
Test mobile data analysis window
Display on the map
Transmitters measured and indexed for the current point.
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Drive Tests Graphic Analysis
Test mobile data analysis window
Synchronisation table – map – measurement
window
Option of displaying variation of any
selected numeric field along the selected
path
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Training Program
1. LTE Concepts
2. LTE Planning Overview
3. Modelling an LTE Network
4. LTE Predictions
5. MIMO Modelling
6. Neighbour Allocation
7. Automatic Resource Planning
8. Frequency Plan Analysis
9. Monte-Carlo Based Simulations
10. Using Drive Tests
11. Terminology and Concepts
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Terminologies and Concepts in Atoll
ResourcesIn Atoll, the term "resource" is used to refer to the average number of resource units, expressed in % (as traffic loads, when the average is performed over a considerably long duration) of the total number of resource units in a superframe of 1 sec.
FrameAn LTE frame is 10 ms long. The duration of a frame is a system-level constant. Each frame comprises 10 1 ms-long subframes, with each subframe containing 2 0.5 ms-long slots. Each slot can have 7 or 6 symbol durations for normal or extended cyclic prefix, respectively, and for a 15 kHz subcarrier width. A slot can have 3 symbol durations for extended cyclic prefix used with a 7.5 kHz subcarrier width. LTE includes specific frame structures for FDD and TDD systems. For TDD systems, two switching point periodicities can be used; half-frame or full frame. Half-frame periodicity provides the same half-frame structure as a TD-SCDMA subframe. The PBCH and the two SCH are carried by subframes 0 and 5, which means that these 2 subframes are always used in downlink. A subframe is synonymous with TTI (transmission time interval), i.e., the minimum unit of resource allocation in the time domain.
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Terminologies and Concepts in Atoll
LTE frame structures (DL: blue, UL: orange, DL or UL: green)
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Terminologies and Concepts in Atoll
Resource Element, Symbol, or Modulation SymbolIn Atoll a symbol refers to one resource element or one modulation symbol, which is 1 symbol duration long and 1 subcarrier width wide.
Symbol DurationIn Atoll a symbol duration refers to one OFDM symbol, which is the duration of one modulation symbol over all the subcarriers/frequency blocks being used.
SubcarrierAn OFDM channel comprises many narrowband carriers called subcarriers. OFDM subcarriers are orthogonal frequency-domain waveforms generated using Fast Fourier Transforms.
Frequency BlockIt is the minimum unit of resource allocation in the frequency domain, i.e., the width of a resource block, 180 kHz. It is a system-level constant. A frequency block can either contain 12 subcarriers of 15 kHz each or 24 subcarriers of 7.5 kHz each.
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Terminologies and Concepts in Atoll
Resource BlockIt is the minimum unit of resource allocation, i.e., 1 frequency block by 1 slot. Schedulers are able perform resource allocation every subframe (TTI, transmission time interval), however, the granularity of resource allocation 1 slot in time, i.e., the duration of a resource block, and 1 frequency block in frequency.
LTE resource blocks
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Terminologies and Concepts in Atoll
LTE Logical Channels: LTE logical channels include:Broadcast Control Channel (BCCH) (DL): Carries broadcast control information.
Paging Control Channel (PCCH) (DL): Carries paging control information.
Common Control Channel (CCCH) (DL and UL): Carries common control information.
Dedicated Control Channel (DCCH) (DL and UL): Carries control information dedicated to users.
Dedicated Traffic Channel (DTCH) (DL and UL): Carries user traffic data.
Multicast Control Channel (MCCH) (DL): Carries multicast control information.
Multicast Traffic Channel (MTCH) (DL): Carries multicast traffic data.
LTE Transport Channels: LTE transport channels include:Broadcast Channel (BCH) (DL): Carries broadcast information.
Paging Channel (PCH) (DL): Carries paging information.
Downlink Shared Channel (DL-SCH) (DL): Carries common and dedicated control information and user traffic data. It can also be used to carry broadcast and multicast control information and traffic in addition to the BCH and MCH.
Uplink Shared Channel (UL-SCH) (UL): Carries common and dedicated control information and user traffic data.
Multicast Channel (MCH) (DL): Carries multicast information.
Random Access Channel (RACH) (UL): Carries random access requests from users.
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Terminologies and Concepts in Atoll
LTE Physical Layer Channels: LTE physical layer channels include:Physical Broadcast Channel (PBCH) (DL): Carries broadcast information.
Physical Downlink Shared Channel (PDSCH) (DL): Carries paging information, common and dedicated control information, and user traffic data. It can also be used to carry broadcast and multicast control information and traffic in addition to the PBCH and PMCH. Parts of this channel carry the primary and secondary synchronisation channels (P-SCH and S-SCH), the downlink reference signals, the physical downlink control channel (PDCCH), the physical HARQ indicator channel (PHICH), and the physical control format indicator channel (PCFICH).
Physical Uplink Shared Channel (PUSCH) (UL): Carries common and dedicated control information and user traffic data.
Physical Uplink Control Channel (PUCCH) (UL): Carries control information.
Physical Multicast Channel (PMCH) (DL): Carries multicast information.
Physical Random Access Channel (PRACH) (UL): Carries random access requests from users.
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Terminologies and Concepts in Atoll
LTE logical, transport, and physical layer channels (DL: blue, UL: orange, DL or UL: green)
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Terminologies and Concepts in Atoll
UserA general term that can also designate a subscriber, mobile, and receiver.
SubscriberUsers with fixed geographical coordinates.
MobileUsers generated and distributed during simulations. These users have, among other parameters, defined services, terminal types, and mobility types assigned for the duration of the simulations.
ReceiverA probe mobile, with the minimum required parameters needed for the calculation of path loss, used for propagation loss and raster coverage predictions.
BearerA Modulation and Coding Scheme (MCS) used to carry data over the channel.
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Terminologies and Concepts in Atoll
Peak RLC ThroughputThe maximum RLC layer throughput (user or channel) that can be achieved at a given location using the highest LTE bearer available. This throughput is the raw data rate without considering the effects of retransmission due to errors and higher layer coding and encryption.
Effective RLC ThroughputThe net RLC layer throughput (user or channel) that can be achieved at a given location using the highest LTE bearer available computed taking into account the reduction of throughput due to retransmission due to errors.
Application ThroughputThe application layer throughput (user or channel) that can be achieved at a given location using the highest LTE bearer available computed taking into account the reduction of throughput due to PDU/SDU header information, padding, encryption, coding, and other types of overhead.
Channel ThroughputsPeak RLC, effective RLC or application throughputs achieved at a given location using the highest LTE bearer available with the entire cell resources (downlink or uplink).
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Terminologies and Concepts in Atoll
User ThroughputsPeak RLC, effective RLC or application throughputs achieved at a given location using the highest LTE bearer available with the amount of resources allocated to a user by the scheduler.
Traffic LoadsThe uplink and downlink traffic loads are the percentages of the uplink and the downlink frames in use (allocated) to the traffic (mobiles) in the uplink and in the downlink, respectively.
Uplink Noise RiseUplink noise rise is a measure of uplink interference with respect to the uplink noise. This parameter is one of the two methods in which uplink interference can be expressed with respect to the noise. The other parameter often used instead of the uplink noise rise is the uplink load factor. Usually, the uplink load factor is kept as a linear value (in %) while the uplink noise rise is expressed in dB. The two parameters express exactly the same information, and can be inter-converted.
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THANK YOU!
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