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ATOLL WiMAX FEATURESATOLL WiMAX FEATURES
Training Programme
1. WiMAX Concepts
2. WiMAX Planning Overview
3. Modelling a WiMAX Network
4. WiMAX Predictions
5. Neighbour Allocation
6. Diversity Modelling
7 Segmentation Modelling7. Segmentation Modelling
8. Resources Automatic Planning
9. Frequency and Preamble Index Plan Analysis
10 Monte Carlo Based Simulations10. Monte-Carlo Based Simulations
© Forsk 2011 Slide 2 of 156Confidential – Do not share without prior permission
1. WiMAX Concepts
OFDM/OFDMA Basics
WiMAX Overview
© Forsk 2011 Slide 3 of 156Confidential – Do not share without prior permission
OFDM/OFDMA Basics
OFDM Definition
Benefits of OFDM
OFDM Channel Structure
OFDMA definition
© Forsk 2011 Slide 4 of 156Confidential – Do not share without prior permission
OFDM Definition (1/2)
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 separated radio signals (subcarriers) using carriers spread across a• OFDM : hundreds to thousands of separated radio signals (subcarriers) using carriers spread across a wideband channel. In OFDM, the sub-carrier frequencies are chosen so that the sub-carriers are orthogonal to each other
Time period for modulation: OFDM symbol• Adjustable guard periods : cyclic prefix (1/4, 1/8, 1/16, 1/32 of the symbol length) used to dissipate
multipath effect
• Symbol rate = f(channel bandwidth carrier spacing*)• Symbol rate = f(channel bandwidth, carrier spacing*)
© Forsk 2011 Slide 5 of 156Confidential – Do not share without prior permission
OFDM Definition (2/2)
OFDM (Orthogonal Frequency Division Multiplexing)
Narrowband orthogonal carriers negligible inter-carrier-interference (ICI)
Centre point of subcarrier c intersects with subcarriers c-1 and c+1 at their 0 values
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
© Forsk 2011 Slide 6 of 156Confidential – Do not share without prior permission
Benefits of OFDM
Negligible Inter-carrier-interference (ICI)Thanks to orthogonal subcarriers which can be transmitted by the use of Fast Fourier Transform (equipment evolution)(equipment evolution)Use of less robust modulation
• Increased data rate
I d R ili (ISI)Improved Resilience (ISI)Sending data across parallel carriers lower rate/carrierFewer modulation symbols longer symbol duration
• Better chance to correctly sample signal
Efficient Usage of the Spectrum
Better Resistance to Frequency Selective Fading ChannelBetter Resistance to Frequency Selective Fading Channel
Multiple Access (Time and Frequency Multiplexing Techniques)
Choice of CarriersSome OFDM systems can train themselves to use the more suitable subchannels in order to limitinterferences (e.g. AMC)
© Forsk 2011 Slide 7 of 156Confidential – Do not share without prior permission
OFDM Channel Structure (1/2)
Symbols
Time
s
Freq
uenc
y
Sub
carri
ers
1 OFDM symbol
© Forsk 2011 Slide 8 of 156Confidential – Do not share without prior permission
OFDM Channel Structure (2/2)
OFDM (Orthogonal Frequency Division Multiplexing)
Uses Fast Fourier Transform and digital filters in order to handle all the carrier information at the same time
OFDM Channel Structure• One channel can be divided into more than one subchannel (Subchannelisation)• The smallest frequency unit that can be allocated to a user is a subchannel• One subchannel contains a number of subcarriers (or tones)• Different subcarriers: Pilot, Guard, Data, DC.
© Forsk 2011 Slide 9 of 156Confidential – Do not share without prior permission
OFDMA Definition (1/2)
OFDMA : Orthogonal Frequency Division Multiple Access
OFDM-TDMAEach user is allocated the full channel for a certain period: capacity wastingUsers are multiplexed in time
Subc
hann
els
Subc
hann
els
OFDMAEach user can be assigned only a part of the entire channel for a certain periodAbility to subdivide the subcarrier population : more than one user served at a timeU lti l d i ti d i fUsers are multiplexed in time and in frequency
hann
els
hann
els
Subc
hSu
bch
© Forsk 2011 Slide 10 of 156Confidential – Do not share without prior permission
OFDMA Definition (1/2)
IEEE 802.16d uses OFDM-TDMA
IEEE 802.16e uses OFDMA
© Forsk 2011 Slide 11 of 156Confidential – Do not share without prior permission
WiMAX Overview
Duplexing Methods
Subcarrier to Subchannel Allocation
Permutation Zones
Frequency Planning
© Forsk 2011 Slide 12 of 156Confidential – Do not share without prior permission
Duplexing Methods
Time Division Duplexing (TDD)Users multiplexed in timeS b d idth f DL d UL bfSame bandwidth for DL and UL subframes
Frequency Division Duplexing (FDD)Users multiplexed in frequencyp q yOne frequency band for DL subframe and one frequency band for UL subframe
Half Duplex FDD (H-FDD)Users multiplexed in frequency and in timeUsers multiplexed in frequency and in timeOne frequency band for DL subframe and one frequency band for UL subframeDL traffic is first served, then UL traffic.
C fi tiConfiguration currently deployed
© Forsk 2011 Slide 13 of 156Confidential – Do not share without prior permission
OFDM/OFDMA in WiMAX (1/2)
IEEE 802.16d uses OFDM-TDMA in the downlink but can use OFDMA in the uplink
Enables mobiles located far from the transmitter to concentrate their transmission power on a smaller part of the total channel bandwidth for extended connectivity
Examples of frames with OFDM-TDMA only or OFDM-TDMA+OFDMA
DL subframe UL subframe
© Forsk 2011 Slide 14 of 156Confidential – Do not share without prior permission
OFDM/OFDMA in WiMAX (2/2)
IEEE 802.16e uses OFDMA in the Downlink and in the Uplink
© Forsk 2011 Slide 15 of 156Confidential – Do not share without prior permission
Subcarrier to Subchannel Allocation
Definition: a subchannel is the elementary unit assigned to one userit is constituted of several subcarriers distributed along the channel
Example in IEEE 802.16d1 channel = 256 subcarriers
256 subcarriers spread across the channel width grouped into:• 16 subchannels (of 12 subcarriers)• 8 pilot subcarriers• 56 null subcarriers (55 guard + 1 centre subcarriers)( g )
© Forsk 2011 Slide 16 of 156Confidential – Do not share without prior permission
Subcarrier to Subchannel Allocation
Subchannelisation in IEEE 802.16eUL and DL subchannelisation is mandatory in 802.16e. This helps to support mobility (speed + handovers)+ handovers)
Two basic subchannelisation strategies (modes):
• PUSC, FUSC, TUSC, OPUSC, OFUSC, etc. : Distributed subcarriers allocation• Over the channel total width for FUSC
• AMC: Adjacent subcarriers allocationj• Possibility to select the more suitable subchannels in order to limit interferences
UL and DL Zone PermBase: seed number that defines, for every subchannel, the list of , y ,Subcarriers to be used
• DL Zone permbase values: from 0 to 31• UL Zone permbase values: from 0 to 69
© Forsk 2011 Slide 17 of 156Confidential – Do not share without prior permission
Permutation Zones (1/2)
The IEEE 802.16e frame can have
Up to 8 permutation zones in the DL subframe
Up to 3 permutation zones in the UL subframe
The first permutation zones in DL and in UL are mandatory and always use the PUSC subchannel allocation modes
Zone switch defined in the DL map
© Forsk 2011 Slide 18 of 156Confidential – Do not share without prior permission
Permutation Zones (2/2)
Each mode is suited for a specific use
AMC (adaptive modulation coding)AMC (adaptive modulation coding)• Adjacent subcarriers• Low frequency diversity• Fixed or pedestrian users
PUSC (partial usage of subchannels)• Division of channel bandwidth in 6 subchannel groups• Each subchannel is obtained from subcarriers distributed over the same 6th of the channel• Protected against frequency-selective fading• More pilots for more secure information• Mobile users
FUSC (full usage of subchannels)• Each subchannels is obtained from subcarrier distributed over the channel width• Each subchannels is obtained from subcarrier distributed over the channel width• Protected against frequency-selective fading (more than in PUSC)• High frequency diversity• Fixed or pedestrian users
© Forsk 2011 Slide 19 of 156Confidential – Do not share without prior permission
Frequency Planning
Usual 1x3x1 and 1x3x3 Allocations
Ch 1 Ch 2 Ch 3
Frequency
Ch 1
Ch 1 Ch 1 Ch 2Ch 3
Ch 1
Segmentation (like Fractional Frequency Reuse in LTE)Possibility to allocate 3 segments of a channel to 3 sectors of a site (in 1st DL PUSC only)Provides better spectrum usage and interference reduction
F1F1
F2 F3F1F1
F3 F2F3 F2
Ch 1
Ch 1 Ch 1 Ch 1
© Forsk 2011 Slide 20 of 156Confidential – Do not share without prior permission
Training Programme
1. WiMAX Concepts
2. WiMAX Planning Overview
3. Modelling a WiMAX Network
4. WiMAX Predictions
5. Neighbour Allocation
6. Diversity Modelling
7 Segmentation Modelling7. Segmentation Modelling
8. Resources Automatic Planning
9. Frequency and Preamble Index Plan Analysis
10 Monte Carlo Based Simulations10. Monte-Carlo Based Simulations
© Forsk 2011 Slide 21 of 156Confidential – Do not share without prior permission
2. WiMAX Planning Overview
WiMAX Features Supported in Atoll
WiMAX Workflow in Atoll
© Forsk 2011 Confidential – Do not share without prior permission Slide 22 of 156
WiMAX Features Supported in Atoll (1/2)
Supports WiMAX NetworksVarious Frequency Bands
Support of TDD and FDD Frame Structures
Possibility of Fixed Subscriber Database for FWA Applications
Support of Directional CPE Antennas
Support of Adaptive Antenna Systems (AAS) using Forsk’s Smart Antenna Model
Signal Level Based Coverage Planning
CINR Based Coverage Planningg g
© Forsk 2011 Slide 23 of 156Confidential – Do not share without prior permission
WiMAX Features Supported in Atoll (2/2)
Supports WiMAX Networks
Supports Multiple Input Multiple Output (MIMO) systemsSupports Multiple Input Multiple Output (MIMO) systems• Modelling of Space-Time Transmit Diversity (STTD/MRC, Matrix A)• Modelling of Single-User MIMO or Spatial Multiplexing (Matrix B)• Modelling of Multi-User MIMO (collaborative MIMO – UL only)
Network Capacity Analysis using Monte Carlo Simulations
Scheduling and Resource Allocation in Two-dimensional Frames
Tools for Resource Allocation (OPTIONAL)• Automatic Allocation of Neighbours• Automatic allocation of Channels• Automatic allocation of Preamble Indexes Specific Module• Automatic Allocation of DL & UL Zone Permbase
Network Verification Possible using Drive Test Data
© Forsk 2011 Slide 24 of 156Confidential – Do not share without prior permission
WiMAX Workflow in Atoll
Open an Existing Project or Create a new one
Network ConfigurationAdd N t k El t ACP- Add Network Elements- Change Parameters
Basic Predictions(Best Server, Signal Level)
ACP
Automatic or Manual Neighbour Allocation
Automatic or Manual Frequency Planning
Traffic Maps
Automatic or Manual Preamble Index Planning
User-defined Values
Monte-Carlo Simulations
Cell Load ConditionsSubscriber Lists
And/or
Prediction Study Reports
Signal Quality and Throughput Predictions
Frequency Plan Analysis
© Forsk 2011 Slide 25 of 156Confidential – Do not share without prior permission
Training Programme
1. WiMAX Concepts
2. WiMAX Planning Overview
3. Modelling a WiMAX Network
4. WiMAX Predictions
5. Neighbour Allocation
6. Diversity Modelling
7 Segmentation Modelling7. Segmentation Modelling
8. Resources Automatic Planning
9. Frequency and Preamble Index Plan Analysis
10 Monte Carlo Based Simulations10. Monte-Carlo Based Simulations
© Forsk 2011 Slide 26 of 156Confidential – Do not share without prior permission
3. Modelling a WiMAX Network
Global Settings
Frequency Band definitionFrequency Band definition
Frame Structure Settings
Frame ConfigurationFrame Configuration
Radio Parameters
Site
Transmitters
Cells
© Forsk 2011 Confidential – Do not share without prior permission Slide 27 of 156
Global Settings: Frequency Band
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
© Forsk 2011 Slide 28 of 156Confidential – Do not share without prior permission
Global Settings: Frame Structure (1/2)
Open the Frame Structure Properties
© Forsk 2011 Slide 29 of 156Confidential – Do not share without prior permission
Global Settings: Frame Structure (2/2)
WiMAX Frame Structure Definition
Percentage dedicated Duration of preamble gto the DL and UL maps in the corresponding subframes
por permanent
information within the frame
Transmit
Relative or absolute DL/UL subframe ratio in the
and receive
time guards
WiMAX frame (TDD)
Frame duration© Forsk 2011 Slide 30 of 156Confidential – Do not share without prior permission
Global Settings: Frame Configuration (1/2)
Frame ConfigurationsTo model the different frame configurations possible for WiMAX networks
Each frame configuration stores the following parameters:• Total number of subcarriers• Number of subcarriers used by the preamble• DL and UL Segmentation supported or not (on the first PUSC zone)• DL and UL Segmentation supported or not (on the first PUSC zone)• DL and UL permutation zones definition
• Subchannel allocation mode (PUSC, FUSC, AMC, etc.)• Number of used and data subcarriers• Number of subchannels per channel• Minimum quality threshold• Maximum distance covered• Maximum speed supported• Permutation zone priority• Antenna diversity support (AAS STTD/MRC SU MIMO AMS MU MIMO)• Antenna diversity support (AAS, STTD/MRC, SU-MIMO, AMS, MU-MIMO)• Definition of secondary groups on the 1st DL PUSC zone
• FFT 1024 and 2048 only
Each cell must have a frame configuration assignedg g
© Forsk 2011 Slide 31 of 156Confidential – Do not share without prior permission
Global Settings: Frame Configuration (2/2)
Permutation Zones (WiMAX 802.16e only)In predictions and during simulations, a permutation zone is assigned to a pixel, subscriber, or mobile in DL and in UL depending on:or mobile in DL and in UL depending on:
• Preamble C/N or C/I+N (as defined in Global Parameters – Advanced Button)• Distance from the base station• The mobile speed• The permutation zone priorityp p y
© Forsk 2011 Slide 32 of 156Confidential – Do not share without prior permission
Radio Parameters Overview
SiteX (longitude) and Y (latitude)
TransmittersActivityAntenna configuration (model, height, azimuth, mechanical & electrical tilts...)
Presented in General Features
g ( g )UL & DL Losses / UL Noise FigurePropagation (Model, Radius and resolution)
CellsCellsFrequency Band & ChannelPreamble IndexFrame configurationPower definitionMin C/NUL & DL LoadDiversity SupportNeighbours
© Forsk 2011 Confidential – Do not share without prior permission Slide 33 of 156
Transmitter ParametersTo define Propagation
Model, Radius and Resolution settings
ContainsAntenna Configuration and Losses
parameters
Contains all CELLS parameters
(see next slide)
DL and UL total losses,
UL noise figure
Antenna Configuration
© Forsk 2011 Slide 34 of 156Confidential – Do not share without prior permission
Cell: Main ParametersCell activity
Base station id
Cell’s frame configuration (PUSC, FUSC zones,
permutations, …) Cell order used for carrier selection
Read-only computed DL d UL b l d ti
Cell’s frequency band
Channel number in the frequency band (and
allocation status)
Preamble index (0…113) + resulting PermBase and segment number (and
and UL symbols durations in the OFDM frame
Power settings on preamble, traffic and pilot subcarriers
allocation status)segment number (and allocation status)
Preamble quality threshold
Resource allocation min reuse distance
DL traffic loads*
WiMAX i t d f th
UL noise rise due to surrounding mobiles* Preamble threshold to switch
from SU-MIMO to STTD/MRC or to activate MU-MIMO
q yused as cell coverage limit
LOAD Conditions
Inputs of the neighbour allocation algorithm
WiMAX equipment used for the bearer selection and the quality
indicator studies
Scheduler used for bearer l ti d
Capacity gain in case of MU-MIMO
© Forsk 2011 Slide 35 of 156Confidential – Do not share without prior permission
allocation algorithm
Neighbour list
selection and resource allocation
* User-defined or simulation output
Cell: Others Parameters
Segmentation parameters*
Effect of external
UL and DL Zone PermBase(seed number defining traffic
subchannels creation)
AAS usage ratio* (and AAS simulation
Results)
Effect of external sources of
interferences
Max UL and DL traffic l d t b t d
UL Traffic Load calculated during
Inputs of the neighbour allocation algorithm
Maximum simultaneous users supported by the cell
loads to be respected during simulations
calculated during simulation
* User-defined or simulation output
allocation algorithm
© Forsk 2011 Slide 36 of 156Confidential – Do not share without prior permission
Training Programme
1. WiMAX Concepts
2. WiMAX Planning Overview
3. Modelling a WiMAX Network
4. WiMAX Predictions
5. Neighbour Allocation
6. Diversity Modelling
7 Segmentation Modelling7. Segmentation Modelling
8. Resources Automatic Planning
9. Frequency and Preamble Index Plan Analysis
10 Monte Carlo Based Simulations10. Monte-Carlo Based Simulations
© Forsk 2011 Slide 37 of 156Confidential – Do not share without prior permission
4. WiMAX Predictions
Introduction
Parameters Used in Predictions
Prediction Settings
Fast Link Adaptation Modelling
Coverage Prediction Examples
Point Analysis StudiesPoint Analysis Studies
© Forsk 2011 Slide 38 of 156Confidential – Do not share without prior permission
Introduction
Coverage PredictionsGeneral Studies based on Preamble Power
Best ser er plot based on Preamble signal le els• Best server plot based on Preamble signal levels• Multiple server coverage based on Preamble signal levels• Preamble signal level plots• Preamble CNR plots
WiMAX UL and DL dedicated studies• Pilot and Traffic Signal Level Plots• Pilot and Traffic CNR Plots• Quality Studies (Preamble, pilot, DL/UL Traffic CINR and interference plots)• Best Bearer and Modulation Plots based on DL and UL Traffic CINR Levels• Throughput and Cell Capacity per pixel plots based on DL and UL Traffic CINR levels
• Peak MAC, Effective MAC, and Application Throughputs• Peak MAC, Effective MAC, and Application Cell Capacities• Peak MAC Effective MAC and Application Aggregate Cell ThroughputsPeak MAC, Effective MAC, and Application Aggregate Cell Throughputs• Peak MAC, Effective MAC, and Application Allocated Bandwidth Throughputs (UL)
Point Predictions
© Forsk 2011 Slide 39 of 156Confidential – Do not share without prior permission
Introduction
Principles of the Studies Based On Traffic
Study calculated for
• Given Load Conditions• UL noise rise
DL t ffi l d• DL traffic load
• A non-interfering user with• A service• A mobilityy• A terminal type with a directive antenna (oriented towards the serving cell)
© Forsk 2011 Slide 40 of 156Confidential – Do not share without prior permission
Load Conditions
Load Conditions are defined in the cells table
Values taken into consideration inValues taken into consideration in predictions for each cell
© Forsk 2011 Slide 41 of 156Confidential – Do not share without prior permission
Service Properties
Parameters Used in PredictionsHighest and lowest bearers in UL and DLBody lossyApplication throughput parameters
© Forsk 2011 Slide 42 of 156Confidential – Do not share without prior permission
WiMAX Bearer Properties
Support for Multiple Modulation and Coding Schemes (MCS)User-selectable Modulations (e.g. BPSK, QPSK, 16QAM, and 64QAM)
User-definable Coding Rates (e.g. 1/2, 2/3, 3/4, etc.)
User-definable Bearer Efficiencies (useful bits per symbol)• Used for channel throughput evaluation
© Forsk 2011 Slide 43 of 156Confidential – Do not share without prior permission
WiMAX Bearer Properties
Link Adaptation in WiMAX
© Forsk 2011 Slide 44 of 156Confidential – Do not share without prior permission
Mobility Properties
Parameters Used in PredictionsMapping between mobilities and thresholds in permutation zone, bearer and quality indicator determination.
© Forsk 2011 Slide 45 of 156Confidential – Do not share without prior permission
Terminal Properties
Parameters Used in PredictionsReception EquipmentAntenna Settings (incl. Antenna diversity support)g ( y pp )Maximum Terminal PowerGain and LossesNoise Figure
© Forsk 2011 Slide 46 of 156Confidential – Do not share without prior permission
Prediction Settings
Coverage Prediction PlotsDo not require Monte-Carlo simulations or subscriber lists
Preamble, Pilot and Traffic signal level based coverage predictions• 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)
• Permutation zone coverage
• Preamble, pilot and traffic C/N plots
• Segment coverage
© Forsk 2011 Slide 47 of 156Confidential – Do not share without prior permission
Prediction Settings
Coverage Prediction PlotsPrinciples
Based on ser defined cell loads or on Monte Carlo sim lation res lts• 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)
Traffic channel CINR based coverage predictionsTraffic channel CINR based coverage predictions• Preamble, Pilot, DL/UL Traffic CINR and Interference Plots
• Possibility to display UL CINR Level for 1 Subchannel• Possibility to display UL Transmission Power per pixel
• Best Bearer plots based on DL and UL Traffic CINR Levels
• Throughput and Cell Capacity per pixel plots based on DL and UL Traffic CINR Levels• Peak MAC, Effective MAC, and Application Throughputs• Peak MAC Effective MAC and Application Cell CapacitiesPeak MAC, Effective MAC, and Application Cell Capacities• Peak MAC, Effective MAC, and Application Aggregate Cell Throughputs
• Uplink Allocated Bandwidth• Peak MAC, Effective MAC, and Application Throughputs• Number of Subchannels
• DL/UL Quality Indicator Plots
© Forsk 2011 Slide 48 of 156Confidential – Do not share without prior permission
Fast Link Adaptation Modelling
Atoll determines, on each pixel, the highest bearer that each user can obtainNo soft handoverC ti t th b t i t f bl CConnection to the best server in term of preamble CBearer chosen according to the radio conditions (traffic channel CINR)
Process : prediction done via look-up tablesp p
Preamble Signal Level Evaluation (C)
Highest Bearer
Mac, Effective And Application Throughput
Calculation
Best Server and Service Area Determination (min
C/N)
Highest Bearer determination limited by the
Service Settings
Quality Indicator (BER,
BLER)C/N)
Permutation Zone Selection
UL and DL Traffic CINR Calculation
BLER)
Permutation Zone Selection (IEEE 802.16e) based on Preamble C/N or C/I+N
© Forsk 2011 Slide 49 of 156Confidential – Do not share without prior permission
Permutation Zone Determination
In predictions and during simulations, a permutation zone is assigned to a pixel, subscriber, or mobile in DL and in UL depending on:
P bl C/N C/I+N ( d fi d i Gl b l P t )Preamble C/N or C/I+N (as defined in Global Parameters)Distance from the base stationThe Mobile SpeedThe Permutation Zone Priority
© Forsk 2011 Slide 50 of 156Confidential – Do not share without prior permission
Interference Estimation
When the permutation zone is selected, Atoll calculates UL and DL CINR according to:The Victim Traffic Power
The Interfering Signals created by:• The interferer pilot and traffic powers• The path loss from the interferer to the victim• Antenna gain (which may be AAS results)• Antenna gain (which may be AAS results)• 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 stationsg
The Interference Reduction factor due to Interfering Base Station’s Traffic Load
The Interference Reduction due to Segmentation (and consequently the mutual overlapThe Interference Reduction due to Segmentation (and consequently the mutual overlap between the segments of the victim and the interfering base stations)
© Forsk 2011 Slide 51 of 156Confidential – Do not share without prior permission
Bearer Selection
When UL and DL CINR are evaluated, the bearer is selected according to:The WiMAX 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 (802.16e only)
The highest possible bearer according to the service settings
© Forsk 2011 Slide 52 of 156Confidential – Do not share without prior permission
Bearer Selection
Scheduler Settings for Bearer Determination
Bearer selection criterion: B i d l i f h hi h b i d• Bearer index: selection of the highest bearer index
• Peak MAC throughput: selection of the highest peak MAC throughput
• Effective MAC throughput: selection of the highest effective MAC throughput
Uplink bandwidth allocation target (WiMAX 802.16e):• Full bandwidth: use of all the subchannels per UL user
• Maintain connection: number of subchannels reduced one by one to increaseMaintain connection: number of subchannels reduced one by one to increase the uplink 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 subchannels reduced to increase the uplink CINR so
that the mobile is able to get the best bearer available (as defined by the bearer selection criterion)
© Forsk 2011 Slide 53 of 156Confidential – 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 frequency sampling factor
The frame definition in term of number of subcarriers, frame duration, etc. as defined in the global parameters and in the frame configuration (802.16e)
Th li fi tiThe cyclic prefix ratio
The bearer efficiency defined in the selected bearer
© Forsk 2011 Slide 54 of 156Confidential – Do not share without prior permission
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 traffic CINR
The terminal mobility (optionally)
© Forsk 2011 Slide 55 of 156Confidential – Do not share without prior permission
Prediction Examples (General Studies)
Coverage by signal level(Based on preamble power)
Best Server Plot(Based on preamble power)
Number of serversNumber of servers(Based on preamble power)
© Forsk 2011 Slide 56 of 156Confidential – Do not share without prior permission
Prediction Examples (Dedicated Studies)
Coverage by DL CINR(Directional receiver antenna)
Coverage by DL CINR(Isotropic receiver antenna)
© Forsk 2011 Slide 57 of 156Confidential – Do not share without prior permission
Prediction Examples (Dedicated Studies)
Coverage by Bearer (DL)
Coverage by Modulation (DL)
Coverage by ChannelCoverage by ChannelThroughput (DL)
© Forsk 2011 Slide 58 of 156Confidential – Do not share without prior permission
Prediction Examples (Dedicated Studies)
Coverage by Bearer (UL)
Coverage by Modulation (UL)
Coverage by ChannelCoverage by ChannelThroughput (UL)
© Forsk 2011 Slide 59 of 156Confidential – Do not share without prior permission
Point Analysis Tool: Reception
Radio Reception Diagnosis at a Given Point : Reception Analysis
Selection of the value to be Choice of UL&DL load conditions : if (Cells displayed (Preamble, Traffic or Pilot
C or C/N)Table) is selected Analysis based on DL
load and UL noise rise from cells table
Definition of a user- Cell bar graphs (best
Preamble, downlink and uplink traffic
availability (or not)
Definition of a userdefinable “probe"
receiver, indoor or not
Cell bar graphs (best server at the top)
Analysis detail on
© Forsk 2011 Slide 60 of 156Confidential – Do not share without prior permission
ypreamble, downlink
and uplink traffic
Point Analysis Tool: Interference
Radio Interference Diagnosis at a Given Point : Interference Analysis
Choice of UL&DL load conditions : if (Cells Table) is selected Analysis based on DL load and UL noise rise from cells table
Selection of the value to be displayed (RS, SS, PDSCH, RSRP)
Serving Cell(C)
Total Level of Interference
(I + N)
Definition of a user-definable “probe"
receiver indoor or not
(I + N)
List of Interfering Cells
© Forsk 2011 Slide 61 of 156Confidential – Do not share without prior permission
receiver, indoor or not
Training Programme
1. WiMAX Concepts
2. WiMAX Planning Overview
3. Modelling a WiMAX Network
4. WiMAX Predictions
5. Neighbour Allocation
6. Diversity Modelling
7 Segmentation Modelling7. Segmentation Modelling
8. Resources Automatic Planning
9. Frequency and Preamble Index Plan Analysis
10 Monte Carlo Based Simulations10. Monte-Carlo Based Simulations
© Forsk 2011 Slide 62 of 156Confidential – Do not share without prior permission
5. Neighbour Allocation
Definitions
Importing Neighbours
Neighbour Automatic Allocation
Displaying Neighbour Relations on the Map
Modifying Neighbour Relations Manuallyy g g y
Exporting Neighbour Relations
© Forsk 2011 Slide 63 of 156Confidential – Do not share without prior permission
Definitions
Reference CellThe cell to which you are allocating neighbours
Possible NeighboursThe cells that fulfil the requirements to be neighbours
Intra-technology NeighboursThe cells defined as neighbours that use the same technology as the reference cellE.g., UMTS-UMTS, GSM-GSM, LTE-LTE
Inter-technology NeighboursThe cells defined as neighbours that use a technology other than the reference cell technologyE.g., UMTS-GSM, UMTS-LTE, GSM-LTE
© Forsk 2011 Slide 64 of 156Confidential – Do not share without prior permission
Importing Neighbours (1/2)
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
© Forsk 2011 Slide 65 of 156Confidential – Do not share without prior permission
Importing Neighbours (2/2)
© Forsk 2011 Slide 66 of 156Confidential – Do not share without prior permission
Neighbour Automatic Allocation (1/4)
Possibility to define neighbourhood constraints to be considered during the automatic neighbour allocation
List of neighbourhood relationships you may force or forbid
Allocation ParametersMaximum number of neighbours
• Global value for all the transmitters or value specified for each transmitterMaximum inter-site distanceAllocation strategy based on the overlapping of cell coverage
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Neighbour Automatic Allocation (2/4)
Coverage conditions Calculation options
Overlapping criterion
Do not select the option ifStart allocation
Do not select the option if you want to keep existing
neighbours
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Neighbour Automatic Allocation (3/4)
Overlapping Criterion
% min covered area is defined by the formula : (S ∩ S ) / S where :% 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 preamble signal level cell B (candidate)level cell B (candidate)
Best preamble signal level cell A (reference) Cell B
Best server
Cell A
Handover end
area
Best server area
Preamble signal threshold (from preamble quality C/N threshold –
global or per cell)Handover start
Handover endarea
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Neighbour Automatic Allocation (4/4)
Allocation ResultSorted list of neighbours with allocation reasons and importance value (0-1)
Allocation results
Sort and filtering tools
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Commit selected neighbours only
Summary report listing existing, new and removed neighbours
Displaying Neighbour Relations on the Map (1/3)
Select the icon in the toolbar and click a transmitter on the map
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Displaying Neighbour Relations on the Map (2/3)
Additional Display Options
Cli k th i f th t lbClick the icon from the toolbar
Symmetric link: site10_2(0) is neighbour of site22_3(0) and
vice-versa
Di ti f th i hb
Inwards link: site22_3(0) is neighbour of site9_3(0)
Direction of the neighbour relation
Outwards link: site1_2(0) is neighbour of site22_3(0)
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Displaying Neighbour Relations on the Map (3/3)
Possibility to display coverage area of cell’s neighbours according to any neighbour characteristics on the map
Calculate and display a “coverage by transmitter” on the map
Display neighbour relations 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
F i t i i hb h d li k lFor intra-carrier neighbourhood links only
Possibility to add/remove neighbours in the cell property dialogueNeighbour list of BRU038 2(0)_ ( )
List of transmitters within a 30 km radius from the selected one (sorted in a
ascending inter-site distance order)
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Exporting Neighbour Relationships
Possibility to copy/paste or to export the list of neighbours
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Training Programme
1. WiMAX Concepts
2. WiMAX Planning Overview
3. Modelling a WiMAX Network
4. WiMAX Predictions
5. Neighbour Allocation
6. Diversity Modelling
7 Segmentation Modelling7. Segmentation Modelling
8. Resources Automatic Planning
9. Frequency and Preamble Index Plan Analysis
10 Monte Carlo Based Simulations10. Monte-Carlo Based Simulations
© Forsk 2011 Slide 76 of 156Confidential – Do not share without prior permission
6. Diversity Modelling
Diversity Modelling Overview
MIMO Settings and Modelling
MIMO Effect in Calculations
AAS Settings and Modelling
AAS Effect in Calculations
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Diversity Modelling Overview
Antenna Diversity Principles
Transmission technique to carry the information along different paths
Aim : improve signal quality by compensating multi-path interferences
Antenna Diversity Modes in Atoll WiMAX
Smart antenna systemsy• Digital signal processing with more than one antenna element
• Locate and track various types of signals• Dynamically minimise interference and maximise wanted signal reception
M i b i t d i th di ti f th t d i l (UL DL)• Main beam pointed in the direction of the wanted signal (UL + DL)
• One or more nulls in the direction of the interfering signals (optimum Beamformer model only)
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Diversity Modelling Overview
Antenna Diversity Modes in Atoll WiMAXMultiple Input Multiple Outputs (MIMO) systems
Space Time Transmit Di ersit (STTD)/Ma imal Ratio Combining (MRC)• Space-Time Transmit Diversity (STTD)/Maximal Ratio Combining (MRC)• More than one transmission antenna to send the same data• Improvement of CINR Higher bearer Higher throughput
• Single-User MIMO or Spatial Multiplexing (SM)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 STTD/MRC as Preamble quality (CNR or CINR) conditions get
worse than a given threshold
• Multi-User MIMO or collaborative MIMOM lti l i f l ith d h di diti• 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
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MIMO Settings in Atoll WiMAX
Base Stations and User Equipment support MIMO systemsGains graphs available in reception equipment
Numbers of Transmission and Reception Antennas at the base station and user equipment
Modelling of Four MIMO Systems:Modelling of Four MIMO Systems:STTD/MRC (space-time transmit diversity) or STC (space-time coding)SM (Spatial Multiplexing)AMS (Adaptive MIMO Switch)MU MIMO (Multi user MIMO or collaborative MIMO)MU-MIMO (Multi-user MIMO or collaborative MIMO)
STTD/MRC, or Matrix A MIMO, improves the CINR Usually used in coverage areas with bad CNR/CINR conditions
SM (or Matrix B MIMO) and MU-MIMO improve throughput Usually used in coverage areas with good CNR/CINR conditions
AMS-capable equipment can switch from SM to STTD/MRC as the Preamble CNR/CINR worsens
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MIMO Settings in Atoll WiMAX
Space-time Transmit Diversity ModellingSTTD/MRC gain depending on the MIMO configuration
Additional STTD/MRC gain per clutter class (DL and UL)
Sum of the gains applied on traffic CINR
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MIMO Settings in Atoll WiMAX
Spatial Multiplexing ModellingMaximum 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))
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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
Cell’s frame configuration (PUSC, FUSC zones, permutations, …)* in
which some permutation zones ( Ssupport or not diversity (AAS,
STTD/MRC, SU-MIMO (SM), AMS or MU-MIMO)
Minimum threshold used as :- Preamble C/N or C/I+N to switch
from SU-MIMO to STTD/MRC- Minimum Preamble C/N to activate
MU-MIMO(If t d i th l t d(If supported in the selected
permutation zone)
Uplink capacity gain due to MU-MIMO. The cell capacity is multiplied
by this gain at pixels where MU-MIMO is used
* IEEE 802.16e WiMAX mobile only
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MIMO Settings in Terminals
Reception equipment defining SU-MIMO and
STTD/MRC gains
Selection of the supported Number of transmission (UL) and reception (DL) antennas
diversity technique (none, AAS, MIMO or AAS+MIMO)
in the case of MIMO-capable terminal
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MIMO Effect in Computations
Predictions and SimulationsOn each pixel, a receiver is connected to its best server (in term of preamble C/N)
MIMO is possible if :• MIMO settings are defined in the WiMAX equipment selected at the cell – for UL – (or terminal – for DL
–) level• MIMO is supported by the user’s terminalMIMO is supported by the user s terminal• A frame configuration supporting MIMO (STTD/MRC, SU-MIMO, AMS, MU-MIMO) on some
permutation zones is assigned to the serving cell• The calculated preamble C/N or C/I+N permits one of these permutation zones to be served
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MIMO Effect in Computations
Coverage Prediction Examples (MIMO system)
Coverage by DL CINR(MIMO with 2*2 antenna)
Coverage by DL CINRCoverage by DL CINR(Without MIMO)
CINR improved for low values (due to STTD/MRC)
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Smart Antenna Modelling
Smart Antenna EquipmentTransmitters can have adaptive/smart antennasF k’ d ti t d l il bl b d f ltForsk’s adaptive antenna model available by defaultBased on MMSE (Minimum Mean Square Error) algorithmAAS-compatible mobiles are allocated to the AAS-compatible permutation zonesDefinition of the number of elements and the pattern of each elementAAS are considered in the Monte-Carlo simulations and coverage predictions
Pattern used for the
© Forsk 2011 Slide 88 of 156Confidential – Do not share without prior permission
Pattern used for the preamble transmission around the transmitter
AAS Settings in Transmitters
Selection of an optional adaptive antenna
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AAS Settings in Cells
Cell’s frame configuration (PUSC, FUSC zones permutations )* inFUSC zones, permutations, …)* in
which some permutation zones support or not diversity (AAS,
STTD/MRC, SU-MIMO (SM), AMS or MU-MIMO)
* IEEE 802.16e WiMAX mobile only
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AAS Settings in Terminals
Selection of the supported diversity technique (none,
AAS, MIMO or AAS+MIMO)
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AAS Effect in Computations
Predictions and SimulationsOn each pixel, a receiver is connected to its best server (in term of preamble C/N)
AAS is possible if :• Smart antenna equipment is defined at the transmitter level• AAS is supported by the user’s terminal• A frame configuration supporting diversity AAS on some permutation zones is assigned to the serving• A frame configuration supporting diversity AAS on some permutation zones is assigned to the serving
cell• The calculated preamble C/N or C/I+N permits one of these permutation zones to be served
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AAS Effect in Computations
Coverage Prediction Examples (AAS system)
Coverage by DL CINR(With AAS)
C b DL CINRCoverage by DL CINR(Without AAS)
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AAS Effect in Computations
Specific AAS Simulation ResultsFor each cell with smart antenna equipment, the obtained transmitted power and UL noise rise are expressed in term of patterns and can be used in predictions (either by committingrise are expressed in term of patterns and can be used in predictions (either by committing them to the cell table or by selecting a specific simulation or group of simulations)
• DL pattern: angular distribution of transmitted power (spectral power density)
• UL pattern: angular distribution of noise rise
© Forsk 2011 Slide 94 of 156Confidential – Do not share without prior permission
Training Programme
1. WiMAX Concepts
2. WiMAX Planning Overview
3. Modelling a WiMAX Network
4. WiMAX Predictions
5. Neighbour Allocation
6. Diversity Modelling
7 Segmentation Modelling7. Segmentation Modelling
8. Resources Automatic Planning
9. Frequency and Preamble Index Plan Analysis
10 Monte Carlo Based Simulations10. Monte-Carlo Based Simulations
© Forsk 2011 Slide 95 of 156Confidential – Do not share without prior permission
7. Segmentation Modelling
Preamble Index Overview
DL Segmentation ModellingOverviewSettingsSettingsEffect in Predictions
UL Segmentation ModellingS iSettingsEffect in Predictions
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Preamble Index Overview (1/5)
Preamble DefinitionThe downlink transmission starts with an OFDM symbol dedicated to the preamble
The downlink subframe is divided into 3 segments
Each segment uses a different preamble carrier set, i.e., Subcarriers used to transmit the blpreamble
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Preamble Index Overview (2/5)
Cell Search and SelectionIt selects the preamble whose PN sequence gives the best correlation. Once the preamble selected the mobile now knows and recognizes its serving cellselected, the mobile now knows and recognizes its serving cell
The PN sequence corresponds to a preamble index, which gives the following information• Segment number: 0, 1, or 2• IDCell (DL permbase for the first DL PUSC permutation zone): 0 to 31• IDCell (DL_permbase for the first DL PUSC permutation zone): 0 to 31
• Cell permbase in Atoll
Therefore, it knows which OFDM symbols and subchannels to listen to for reading the FCH, DCD, UCD, DL-map, and UL-mapDCD, UCD, DL map, and UL map
mbl
e
mbl
e
mbl
e
Preamble carrier set 0 Preamble carrier set 1 Preamble carrier set 2
Pre
am
Pre
am
Pre
am
Preamble carrier set 0Segment 0
Preamble carrier set 1Segment 1
Preamble carrier set 2Segment 2
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Preamble Index Overview (3/5)
Preamble Index FunctionCell Identification Parameter
Cell Search and Selection is based on preamble indexes
114 Preamble Indexes defined by the IEEE
Each Preamble Index has an associated pseudo-noise sequence
The 114 PN Sequences are (nearly) orthogonal
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Preamble Index Overview (4/5)
Preamble Index Function (contd.)Subcarriers used for preamble transmission are interlaced
Preamble subcarriers are modulated using BPSK1/2 with PN sequences
The PN sequence is transmitted using the preamble carrier set, i.e., the subcarriers used by th blthe preamble
Cell search and selectionAny mobile trying to connect to the network receives preambles from many cells
It calculates the correlation of all the received PN sequences by comparing them with the 114It calculates the correlation of all the received PN sequences by comparing them with the 114 stored in its memory
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Preamble Index Overview (5/5)
Mapping Between the Preamble Index and the SegmentationExample of segmentation for 3 cells : preamble index 0, 32, 64
Permbase 0• Permbase 0• Segments 0, 1 and 2
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DL Segmentation Overview (1/2)
Segmentation and Fractional Frequency ReuseIEEE 802.16e (DL PUSC zones only)P ibilit t ll t t f th ti b d idth t ll (DL bf )Possibility to allocate a part of the entire bandwidth to a cell (DL subframe)Provides better spectrum usage and interference reductionMaximum of 3 segments (preamble index only supports 0, 1, 2)
• Preamble always segmented (using every 3rd subcarrier)
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DL Segmentation Overview (2/2)
The segmented zone uses a segment of the entire channel bandwidth (typical:1/3rd)
The maximum throughput of a 1/3rd segment is 1/3rd of the throughput of a channel
Definition of segmentation usage ratioUsed to compute the interference between cellsUsed to compute the interference between cellsRepresents the segmented part percentage of the total traffic load
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DL Segmentation: Network Settings
DL Segmentation is possible when the Frame supports itEffect on traffic only since preamble is always segmentedOnly for the first PUSC DL Permutation zones
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DL Segmentation Settings: Cells
Cell’s frame configuration (PUSC, FUSC zones, permutations, …)*
where segmentation may be supported or not
Cell’s frequency band
Channel number in the frequency band The same channel must beband. The same channel must be
used between cells for which segmentation is applied
Preamble index (0…113)* and lti P B ( IDC ll) dresulting PermBase (or IDCell) and segment number (0,1 or 2).
Segmentation between cells is optimal when PermBase is identical and segment is different (must be
define even without segmentation in order to model the preamble
segmentation)
Segmentation usage ratio* (used in the interference estimation)
d l i S iand resulting Segmentation Switching Point
* User-defined or simulation output© Forsk 2011 Slide 105 of 156Confidential – Do not share without prior permission
DL CINR PUSC Only (Without Segmentation)
Each cell uses the full channel bandwidth
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DL CINR PUSC Only (With Segmentation)
Each cell uses 1/3rd of the channel bandwidth
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DL CINR PUSC segmented + non segmented
Each cell has a PUSC zone with 1/3rd channel bandwidth + a PUSC zone with the entire channel bandwidth
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DL throughput PUSC only (Without Segmentation)
Each cell uses the full channel bandwidth
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DL throughput PUSC only (With Segmentation)
Each cell uses 1/3rd of the channel bandwidth
Conclusion : higher CINR, larger coverage but poorer throughput since 1/3rd of the beamwidth is used © Forsk 2011 Slide 110 of 156Confidential – Do not share without prior permission
DL throughput PUSC segmented + non segmented
Each cell has a PUSC zone with 1/3rd channel bandwidth + a PUSC zone with the entire channel bandwidth
Conclusion : comparable CINR/throughput in the common covered areas, but additional coverage (and throughput) in the PUSC segmented areas© Forsk 2011 Slide 111 of 156Confidential – Do not share without prior permission
UL Segmentation: Network Settings
UL Segmentation is possible when the Frame supports itOnly for PUSC UL Permutation zonesCannot be used as is for predictions: need a Simulation to calculate UL segmented Noise Rise
© Forsk 2011 Slide 112 of 156Confidential – Do not share without prior permission
UL Segmentation Settings: Cells
Cell’s frame configuration (PUSC, FUSC zones, permutations, …)*
where segmentation may be
Cell’s frequency band
where segmentation may be supported or not
Cell s frequency band
Channel n mber in the freq encChannel number in the frequency band. The same channel must be
used between cells for which segmentation is applied
Segmented Zone UL Noise Rise* (used in the interference estimation
when calculating a prediction)
* User-defined or simulation output© Forsk 2011 Slide 113 of 156Confidential – Do not share without prior permission
Training Programme
1. WiMAX Concepts
2. WiMAX Planning Overview
3. Modelling a WiMAX Network
4. WiMAX Predictions
5. Neighbour Allocation
6. Diversity Modelling
7 Segmentation Modelling7. Segmentation Modelling
8. Resources Automatic Planning
9. Frequency and Preamble Index Plan Analysis
10 Monte Carlo Based Simulations10. Monte-Carlo Based Simulations
© Forsk 2011 Slide 114 of 156Confidential – Do not share without prior permission
8. Resources Automatic Planning
Automatic Frequency PlanningAFP OverviewAFP PAFP Process Interference Matrix CalculationRunning the Frequency Automatic AllocationFrequency Allocation Examples
Automatic Preamble Index PlanningPreamble Index Planning ProcessRunning the Preamble Index Automatic AllocationgPreamble Index Allocation Examples
Automatic UL/DL Zone PermBase PlanningUL/DL Z P B O iUL/DL Zone PermBase OverviewUL/DL Zone PermBase Planning ProcessRunning the UL/DL Zone PermBase Automatic Allocation
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AFP Overview (1/2)
Goal: Optimize the Network Frequency Allocation to minimize interference
InputsCells settings
• Frequency band(s): Atoll can work with several bands• Locked Channels (Optional)
Reuse Constraints definition:• Interferences (Interference Matrix calculation)• Minimum Reuse distance
N i hb l ti• Neighbour relations
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AFP Overview (2/2)
Based on an Iterative Cost-based Algorithm
Th l ith t t ith th t f l ( d i iti l t t )The algorithm starts with the current frequency plan (used as initial state)Different Frequency Plans are then evaluated and a Cost is calculated for each of them
The best frequency allocation plan is the one with the lowest global cost
The cost is calculated thanks to:• Interference matrices
• Probabilities of interference in co- and adjacent channel casesA b bilit l l t d f h f h i t f d i t f i ll i• A probability calculated for each case for each interfered-interfering cell pair
• Distance relation• Avoid Frequency reuse between cells for which the inter-site distance is lower than a
“Min Reuse Distance”• Taking into account Distance and Cells’ Azimuth
• Neighbours• Taking into account Neighbours relation’s importance relation (co-site, adjacent)
© Forsk 2011 Slide 117 of 156Confidential – Do not share without prior permission
AFP Process
1. Define Radio Parameters at Cells levela) Frequency Band Allocationb) F All ti St t N t All t d L k db) Frequency Allocation Status: Not Allocated or Lockedc) Minimum reuse Distance (optional)
2. Import / Calculate a Neighbour Plan
3. Import / Calculate an Interference Matrix
4 R th A t ti F All ti t l4. Run the Automatic Frequency Allocation tool
5. Commit and Analyse Results
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Interference Matrix Calculation (1/2)
DefinitionFor 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
Tx AVictim Transmitter
Serving Area
Tx BInterfering Transmitter
Victim Transmitter
Area where Tx B is interfering Tx A
Interference Probability = 50%
In other words 50% of TxA’s Serving Area is interfered by TxB
Co-Channel interference occurs when: Adjacent Channel interference occurs when:
In other words, 50% of TxA s Serving Area is interfered by TxB
P blCMiC PreambleCMinC
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PreambleNCMin
NMIC
Q
PreambleN
MinN
fMI
ASF
Q
Interference Matrix Calculation (2/2)
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Running the Frequency Automatic Allocation
Automatic Resource Allocation Process Possibility to select the Resource to be allocated (Frequencies, Preamble Indexes...)
Interference Matrix selection
(among calculated ones)
Allocation constraints
C i
Allocated channels
Commit channels to
cells
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Run the calculation
Frequency Allocation Examples (1/5)
Automatic Frequency Allocation in Atoll (Example)Same channel all over
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Frequency Allocation Examples (2/5)
Automatic Frequency Allocation in Atoll (Example)Manual allocation with 3 channels
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Frequency Allocation Examples (3/5)
Automatic Frequency Allocation in Atoll (Example)Automatic allocation with 3 channels
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Frequency Allocation Examples (4/5)
Automatic Frequency Allocation in Atoll (Example)Manual allocation with 6 channels
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Frequency Allocation Examples (5/5)
Automatic Frequency Allocation in Atoll (Example)Automatic allocation with 6 channels
© Forsk 2011 Slide 126 of 156Confidential – Do not share without prior permission
Preamble Index Allocation Process (1/2)
Philosophy of the Preamble Index Automatic Allocation tool is really similar to AFP
GoalsAvoid using the same PN sequence in nearby cells
• Can cause problems in cell search and selectionAvoid using the same segment to nearby cells
• Can cause a lot of interference on FCH and mapsUse preferably the same Cell PermBase to cells of the same site
• Can help in measurements and handover procedures
Automatic Preamble Index Allocation PrerequisitesDefine Radio Parameters at cells level
• Frequency Plan: a channel manually (or automatically) assigned to each cell• Preamble Index domain (v3.1.1)• Preamble Index and Segment allocation status• Minimum Reuse Distance (optional)• Segmentation support (optional)
Neighbour planInterference Matrix (as explained previously)
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Preamble Index Allocation Process (2/2)
Automatic Preamble Index Allocation in AtollBased on an iterative cost-based algorithm
Different Preamble Index allocation plans are tried and a cost calculated for each
The best Preamble Index 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)
C ll P B t t ( ti l)• Cell PermBase strategy (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 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)
© Forsk 2011 Slide 128 of 156Confidential – Do not share without prior permission
Running the Preamble Index Automatic Allocation
Automatic Preamble Index AllocationPreamble Index
allocation domainallocation domainCell PermBase
Strategy
I iti l
Allocation constraints
Initial Allocation
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Run PI allocation
Preamble Index Allocation Results (1/4)
Committing calculated Preamble Indexes
Commit calculated Preamble Indexes to
Cells
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Cells
Preamble Index Allocation Results (2/4)
Example 1 : Same Preamble Index (same Segment and Cell PermBase) all over
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Preamble Index Allocation Results (3/4)
Example 2 : Manual Allocation with three Preamble Indexes (0, 32, 64)
Sect 0: PI 0, seg 0, PB 0
S 1 PI 32 1 PB 0Sect 1: PI 32, seg 1, PB 0
Sect 2: PI 64, seg 2, PB 0
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Preamble Index Allocation Results (4/4)
Example 3 : Automatic Preamble Index Allocation
© Forsk 2011 Slide 133 of 156Confidential – Do not share without prior permission
UL/DL Zone PermBase Allocation Process (1/2)
Philosophy of the UL/DL Zone PermBase Automatic Allocation similar to AFP
GoalAvoid using the same Zone PermBase (Seed Number) in nearby cells
Automatic Preamble Index Allocation PrerequisitesAutomatic Preamble Index Allocation PrerequisitesDefine Radio Parameters at cells level
• Frequency Plan: a channel manually (or automatically) assigned to each cell• Allocation Status• Minimum Reuse Distance (optional)
Neighbour planInterference Matrix (as explained previously)
No impact on Predictions and Simulations
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Running the UL Zone PermBaseAutomatic Allocation
Automatic UL Zone PermBase AllocationUL Zone PermBase allocation domainallocation domain
I iti l
Allocation constraints
Initial Allocation
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Commit results to cells
Run allocation
Running the DL Zone PermBaseAutomatic Allocation
Automatic DL Zone PermBase AllocationDL Zone PermBase allocation domainallocation domain
I iti l
Allocation constraints
Initial Allocation
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Commit results to cells
Run allocation
Training Programme
1. WiMAX Concepts
2. WiMAX Planning Overview
3. Modelling a WiMAX Network
4. WiMAX Predictions
5. Neighbour Allocation
6. Diversity Modelling
7 Segmentation Modelling7. Segmentation Modelling
8. Resources Automatic Planning
9. Frequency and Preamble Index Plan Analysis
10 Monte Carlo Based Simulations10. Monte-Carlo Based Simulations
© Forsk 2011 Slide 137 of 156Confidential – Do not share without prior permission
9. Frequency and Preamble Index Plan Analysis
Channel and Preamble Index Search Tools
Preamble Index Allocation Audit
Preamble Index Distribution Histogram
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Search Tool Overview
Tool to visualise channel and Preamble Index reuse on the map
Possibility to find cells which are assigned a given :y g g• Frequency band + channel• Preamble Index • Segment• Permbase
Way to use this tool
Create and calculate a coverage by transmitter with a colour display by transmitterg y p y y
Open the “Find on Map” tool available in the Edit menu (or directly in the toolbar )
© Forsk 2011 Slide 139 of 156Confidential – Do not share without prior permission
Channel Search Tool
Channel Reuse on the Map
Resource
Frequency band and
Resource Selection
band andChannel number
Colours given to transmitters• Red: co-channel transmitters
• Yellow: multi-adjacent channel (-1 and +1) transmitters
© Forsk 2011 Slide 140 of 156Confidential – Do not share without prior permission
Yellow: multi adjacent channel ( 1 and +1) transmitters• Green: adjacent channel (-1) transmitters• Blue: adjacent channel (+1) transmitters
• Grey thin line: other transmitters
Preamble Index Search Tool
Preamble Index, Permbase and Segment Reuse on the Map
Resource
Resource
Resource Selection
Resource Type and
Value
Colours given to transmitters• Red or Grey thin line: if the transmitters carries or not
the specified resource value (Preamble Index, Cell PermBase)
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Preamble Index Allocation Audit (1/2)
Verification of the allocation inconsistenciesRespect Preamble Index Allocation DomainR t f i i di tRespect of a minimum reuse distanceRespect of neighbourhood constraints (two neighbour cells must have different PI)Respect of Permbase and Segment allocation strategy
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Preamble Index Allocation Audit (2/2)
Audit resultsInconsistencies are displayed in the default text editor
The Minimum Distance constraint is fulfilled
The Allocation Domain constraint is fulfilled
Th N i hb ll ll t d thThese Neighbour cells are allocated the same Preamble Index
The Permbase and Segment strategies are fulfilled
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Preamble Index distribution Histogram
View of the Preamble Index Distribution
Dynamic pointer
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Training Programme
1. WiMAX Concepts
2. WiMAX Planning Overview
3. Modelling a WiMAX Network
4. WiMAX Predictions
5. Neighbour Allocation
6. Diversity Modelling
7 Segmentation Modelling7. Segmentation Modelling
8. Resources Automatic Planning
9. Frequency and Preamble Index Plan Analysis
10 Monte Carlo Based Simulations10. Monte-Carlo Based Simulations
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10. Monte-Carlo Based Simulations
Simulation Process
Simulation Creation
Simulation Results
Analysis of Simulations
Specific AAS Simulation Resultsp
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Simulation Process (1/2)
What’s a Simulation in Atoll?
Distribution of Users at a Given Moment (= Snapshot)Distribution of Users at a Given Moment (= Snapshot)
Purpose
Simulate the network regulation mechanisms for a user distribution
Analyse the network capacity
Steps of the WiMAX Simulation
1. Obtaining a Realistic User Distribution
2. Modelling the Network Regulation Mechanisms
3. Calculating Network Parameters
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Simulation Process (2/2)
Requirement: Traffic Maps and/or Subscriber Lists
Traffic Maps
Managed from the Traffic Maps Folder• Geo tab of the Explorer window
Based on Service and User Modelling
Main Types of Traffic Maps• User profile environment based traffic maps• Sector traffic maps
Subscriber Lists
Managed from the Subscribers Folder• Network tab of the Explorer window
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Obtaining a Realistic User Distribution
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 trialA 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 ifg g g (
the simulation is based on a subscriber list)
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Modelling the Network Regulation Mechanisms
Iterative Algorithm
Same User Distribution Considered for Each Iteration
During each iteration, all the users attempt to connect one by one to network transmitters
Process Repeated Until Convergence
Regulation MechanismsRegulation Mechanisms
Intelligent scheduling and radio resource management• Subchannels Allocation• Power Control• DL Cell Load• UL Noise Rise
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Scheduling in Simulations
Scheduling and Radio Resource ManagementFiltering of mobiles up to cell capacity limits (max UL and DL loads)
Allocation of resources according to GoS class, service priorities and cell scheduler
Different schedulers available:• Proportional Fair• Proportional Demand• Biased (GoS class)• Max Aggregate Throughput
First pass• Resource allocation for the minimum throughput demands depending on the service priorities of the
users (GoS class + priority)• Minimum throughput demand for UGS, rtPS, ErtPS, nrtPS categories
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 of rtPS, ErtPS, nrtPS and BE categories
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Simulation Creation
Optional growing factor on the selected traffic map(s)
Number of simulations to run for the current
session
Selection of traffic map(s) as traffic
input
Selection of subscriber list(s) as traffic input (dedicated to
802 16d)Load constraints to respect
802.16d)during simulations (global value or value per cell)
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Simulation Creation
Number of simulations to run for the current session
Multiplying factor to increase the user density
Constraints to be respected during the simulation and convergence criteriaSelection of traffic map(s) simulation and convergence criteriaas traffic input
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Click the button to calculate the simulation immediately
Simulation Results (1)
Analysis Provided over the Focus Zone
Main Simulation results includePer cell
• UL and DL traffic loads• UL noise rise (incl. AAS results)• Calculation of aggregate cell throughputs for UL and DL
• Peak MAC, effective MAC, and application level• …
Per mobilePer mobile• Serving transmitter and cell• Azimuth and downtilt (towards the serving cell)• Received power from and at the serving cell• DL and UL CINR, best WiMAX bearers, channel and user throughputs
• Peak MAC, effective MAC, and application level• UL transmission power• Number of used subchannels in UL• DL and UL permutation zones (WiMAX 802.16e only)
Connection status and rejection cause• 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 and DL traffic loads, the UL noise
rise, the segmentation usage (if any), the
adaptive antenna system results (if any) 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 WiMAX Prediction Studies Based on SimulationsAnalysis of a single simulation
Prediction based on the results of the simulation (DL load, UL noise rise, etc)
Average analysis of all the simulations in a group
Prediction based on the average of simulations in the group (average DL load, average UL noise rise, etc)
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THANK YOU!