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6. GSM Optimization and (E)GPRS Planning and Optimization
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Soc Classification level 1 © Nokia Siemens Networks
GERAN Cross Company TrainingNorth SystemInternal
GERAN Optimization
Day 3, Session 3, 13:00 – 14:30
Soc Classification level 2 © Nokia Siemens Networks
Aim of Session 3 and Session 4
• After Session 3 and Session 4 the participant should – able to summarize the quality improvement steps
– have a view on NetAct Optimizer tool
– able to support GSM optimization projects
– Know the most important elements of (E)GPRS dimensioning, planning and optimization
Soc Classification level 3 © Nokia Siemens Networks
QualityReporting
MonitorQuality
QualityDefinition
Qualityin detail
QualityImprovemen
t
Configurationanalysis
QualityTargets
QualityReporting
MonitorQuality
QualityDefinition
Qualityin detail
QualityImprovemen
t
Configurationanalysis
QualityTargets
QualityImprovement
QualityImprovement
Network Quality CycleQuality Improvement
Soc Classification level 4 © Nokia Siemens Networks
General Quality Improvement
Configuration
Features
HardwareModel Sites
Tilting, modification of directions, etc
Call setup
Traffic
Quality
Mobility
Features to using current configuration better
Expansion
Soc Classification level 5 © Nokia Siemens Networks
Telecom Solution Construction Solution
Shelters
Towers, Masts, Poles
Installation Material Packages
Antenna Systems
Site SupportSystems
Base Stations
CellularTransmission
Systems
Cables & Tools
Model Sites
Soc Classification level 6 © Nokia Siemens Networks
NetAct Optimizer For automated, measurement based optimization of operational GSM&WCDMA networks
Improved optimization accuracy
• Parameter tuning is done based on network statistics – no predictions
• Accurate results with accurate input – no fine tuning
More efficiency via automation
• Seamless support for optimization process phases
• Automated data transfers via NetAct integration
• Visualization and analysis to helpdecision making for optimization tasks
• Focusing on essentials
NetActOptimizer
Soc Classification level 7 © Nokia Siemens Networks
NetAct Optimizer Optimization Process for Operational Networks
WorkflowWorkflowAutomationAutomation
Consistency Consistency checkschecks
Automated Automated changechange
downloaddownload
DecisionDecisionSupportSupport
VisualiseVisualise
AnalyseAnalyse
OptimiseOptimise
ProvisionProvision
OptimiseOptimiseManuallyManually
OptimiseOptimiseAutomaticAutomatic
Elements andElements andConfigurationConfiguration
KPIs and KPIs and alarmsalarms
PerformancePerformanceAnalysisAnalysis
Detect andDetect andDiagnoseDiagnose
CM, PM, FMCM, PM, FMCorrelationCorrelation
AnalysisAnalysis
Verify Verify performanceperformance
ScopeScopeSelectionSelection
Result Result verificationverification
Soc Classification level 8 © Nokia Siemens Networks
NetAct Optimizer Optimizer modules
2G/3G OptimizerGraphical Adjacency Management
Radio Access Configurator
Advanced Visualization for 2G/3G
Automated Adjacency optimization for 2G/3G
Service optimizer for 2G/3G
PM DB
• KPIs for analysis• visualization• optimization
• Actual CM data• Change provisioning
Optional
OptionalOptional
Performance optimization for 2G/3G Optional
Soc Classification level 9 © Nokia Siemens Networks
NetActOptimizer
NetAct Optimizer Optimizer product conceptEfficiency of shared NetAct installation• Common HW, administration, look and feel, documentation• Access to optimisation functionality can be controlled
Automation through seamless NetAct integration• Actual CM data uploaded automatically from RAC DB• Automated access to KPIs
– Nightly calculation from raw counters in PM DB– Import from preferred PM tool (integration project)
• Optimisation results stored as plans in RAC DB
Measurement based optimization for the key tasks• GSM frequency and BSIC plan optimization• Interference control for WCDMA• Seamless adjacency and handover
management for GSM & WCDMA • Capacity and QoS optimisation
Visualisation and analysis functionality• Topology, parameters, KPIs in one view
Soc Classification level 10 © Nokia Siemens Networks
Optimizer interworking in NetActAutomated access of configuration parameters• Uploaded actual CM data updated in Optimizer
nightly from RAC DB– Most important elements and parameters– Site & antenna information to show the cells on map
• Planned data supported, too
Optimization results stored in RAC DB for centralized provisioning• Plans available in CM Operations Manager
Measurement control in NetAct• Activation and control of standard and
special measurements
Automated retrieval of KPIs • Nightly calculation of KPIs from PM DB raw counters
– Fixed KPI formulas used– Daily, Daily BH, Weekly, Weekly BH levels– Selected BSS and RAN KPIs for optimization
• With integration project the KPIs can be retrieved from a preferred PM tool
Soc Classification level 11 © Nokia Siemens Networks
Visualization and analysis
A thorough understanding of the current network status is essential before taking any optimization actions• Configuration audits• Parameter setting checks• Performance overview
Optimizer provides efficient means to view all this geographically• To identify the problematic elements
for further analysis
New technology and services require new knowledge• Optimizer combines the essential information
together for meaningful entities• Easy understanding of the dependencies
Soc Classification level 12 © Nokia Siemens Networks
Common functionality for GSM&WCDMA
Geographical visualization and analysis• KPIs and parameters automatically on map• Customized quality thresholds
Graphical adjacency management• Actual adjacencies on map• Manual or automated distance based
management of all adjacency types• Border area adjacencies• Parameters from templates automatically• Scrambling code collision check and correction• Instant provisioning for Nokia elements
Powerful parameter management with Browser• KPIs and parameters in the same view• Dedicated, customized views per task• One-by-one or mass editing of parameters • Change tracking
Management of plans between RAC and Optimizer
Soc Classification level 13 © Nokia Siemens Networks
Measurement based GSM optimization
BSC
Serving BTS
Interference Matrix generation based on mobile measurements• Control for the BSS measurements• Generation of interference matrix • Verification of interference validity
Interference root cause analysis• Complemented with Timing Advance analysis
Automated Adjacency Management• Automated algorithm to propose optimal adjacencies• Unused adjacency deletion based on HO statistics• Missing ones created based on interference matrix
Performance optimization• Frequency allocation based on
measured interference• All hopping modes supported• All RF hopping types supported• Allocation completed with BSIC allocation
and other parameters
Soc Classification level 14 © Nokia Siemens Networks
Interference matrix from BSS measurementsOptimizer uses the BSS measurements for interference matrix generation and further to adjacency and frequency plan optimization• CF & DAC measurements or totalFEP measurement of S11.5• Method to measure interference in all BCCH frequencies• Fast and efficient measurement process
BSC
BTS
BALBAL BALBAL BALBAL
BAL = All BCCH
BCCH of undefinedcells
...and definedadjacent cells
Active MS
GSM standard HO procedure used in the basis of measurements
• All active mobiles listen the neighboring cell BCCHs and report the 6 strongest to BSC
Special measurement in Nokia BSS• CF and DAC in S10.5, total FEP in
S11.5• Temporary BA lists defined for
measurement period to include all surrounding cell BCCHs
• Mobiles measure all BCCHs in BA list• BSC collects and stores the data and
forwards to NetAct • Data collected for few days
Optimizer generates the interference matrix from the measurements
Soc Classification level 15 © Nokia Siemens Networks
Interference root cause analysis
Optimizer generates the interference matrix automatically
• Co-channel and adjacent –channel matrices
• C/I probability and Average Received Power values calculated
Before the interference is used in optimization measurement validity and interference root cause can be analyzed
• Statistics to verify that the measurements are reliable and thoroughly collected– Amount of sample, traffic, coverage value
• Methods to analyze the interference root cause– Overshooting cells
– Distance to interferer
Soc Classification level 16 © Nokia Siemens Networks
Frequency allocation procedure
Analyze the current performance
• View the KPIs and allocation on map and browser
• DCR, call quality, BCCHs, hopping modes
Collect interference measurements
• With CF and DAC measurements in BSS
Generate and verify interference matrix
• Check that all cells are measured
• Analyse interference location and root cause
Perform allocation
• BCCH and TCH allocation
• RF Hopping allocation: MA-lists, MAIO parameters, HSN
• Other necessary parameters: TSC, BSIC, all IDs
Verify results
• View allocation on graphs, tables and map
Download plan to network with Radio Access Configurator
• Centralised provisioning for the whole area
• Using scheduled download, background DB etc
Soc Classification level 17 © Nokia Siemens Networks
Automated Adjacency Optimization for 2GAutomated adjacency optimization based on measurements
• Deletion of unused adjacencies based on HO criteria– User defines the thresholds for
HO attempts and HO success criteria– Sometimes the corrective action is to tune
the HO parameters, not delete the adjacencies• Adjacency creation based on interference matrix
– Signal strength between source and target cells considered
Result verification on table view and map
Centralized, automated download to network• With Radio Access Configurator
CM Operations Manager• Instant Adjacency Provisioning
activates the provisioning processin background from Optimizer
Soc Classification level 18 © Nokia Siemens Networks
Seamless adjacency management
Graphical adjacency management on map• GSM, WCDMA, inter-system adjacencies
Initial adjacency creation algorithm• Cell location based
Adjacency management over border areas• Controller areas, LAC, PCU areas• NetAct regions, vendor regions
Automated parameter completion from templates• Cell templates from CM Editor are used• Template assignment rules defined in
Optimizer per adjacency type
Instant adjacency provisioning• Activating the provisioning process in
background• Valid for all kinds of adjacencies• Changes still stored into a plan
Soc Classification level 19 © Nokia Siemens Networks
Service OptimizerEDGE capacity analysis for Nokia
Support for identifying and analyzing the capacity bottlenecks in EDGE
• Topology view of the critical chain
• Capacity analysis to identify where the bottlenecks are now– Overview highlighting the poor performance areas and the cause of that
– Detailed visualization of each element / interface situation Radio interface load A-bis/ EDAP pool capacity view BSC/PCU and Gb capacity analysis
• Proposals of corrective actions– Analysis of capacity addition consequences to other interfaces
GGSN
Application
Servers BSC 2GSGSN
Application Servers in Internet
Abis(EDAP)
GbPCU
Soc Classification level 20 © Nokia Siemens Networks
Seamless multi-vendor network optimizationThe current Optimizer functionality and optimization process can be used with any vendor
• Special measurements for 2G and 3G may have vendor dependent limitations
•Border areas / overlapping areas can be handled seamlessly
Data from other vendors is imported and mapped to the data model of the tool
• CM data imported from the other OMC to Radio Access Configurator
•Ready calculated KPIs are retrieved from the preferred PM tool
•Site and antenna data from the one master DB
•Integrations agreed together with the client to ensure perfect fit to the process and other tools
Optimization results exported from RAC for provisioning
Soc Classification level 21 © Nokia Siemens Networks
Effective parameter changesAfter the analysis the corrective actions, parameter changes, can be taken in Optimizer
Browser – the table view for efficient modifications• Ready made combined CM&PM views
– For most important tasks• Dedicated views per task• Data filtering and sorting• Mass editing capabilities• Value consistency checks• Import/Export interfaces• Always up-to date
change tracking
Ready made HSDPA view
Mass editing of parameters
Adjacency parameter & KPI view
Highlights:
Soc Classification level 22 © Nokia Siemens Networks
Allocation result verification and download
Optimizer includes in-built methods to evaluate the optimization results before they are activated in the network
Verification in several levels of details
• Initial evaluation while in allocation tool
• High level analysis on map
• Before provisioning consistency checks can be run Download automatically with RAC
• Directly or via background DB
• In GSM&WCDMA NWs the BCCH information is automatically updated to WCDMA cells having neighborhood with GSM cells
Soc Classification level 23 © Nokia Siemens Networks
Support for planned cells and TRXsOptimizer can also be used for finding initial frequencies and adjacencies for new, planned cells Initial frequency for new TRX• Optimizer has functionality to select the best frequency for a new TRX without complete allocation process• The existing interference matrix is used •The frequency can be reserved before the TRX is implemented
Initial adjacencies and frequencies for a new cell• New cell needs to be created in RAC as planned cell• The cell is visible in Optimizer• Existing interference matrix is complemented with predicted interference including the new cell• Frequency and BSIC allocation is run• Adjacency generation is run• These settings are complemented to the planned cell data in RAC
– Taken into use when the cell is implemented and when parameters are provisioned for launch
Soc Classification level 24 © Nokia Siemens Networks
GERAN Cross Company TrainingNorth SystemInternal
(E)GPRS Planning and Optimization
Day 3, Session 4, 14:45 – 16:00
Soc Classification level 25 © Nokia Siemens Networks
(E)GPRS Network Infrastructure
GPRS IPBackboneNetwork
DNS
CG
GGSN
Internet
Corporate 1Intranet
LIG
Corporate 2Intranet
SS7Network
PSTNMSCBSCBTS
MS
EIR
HLR/AuC
SMS-GMSC
SGSN
SGSN
SGSN
MODEMPOOL FOR DIALUP
Nokia IP650 sec GW
Router
Router
RouterSTM-1
STM-1
SGSN
GGSN
Router
Router
Nokia Security GW
LAN SWITCH
MODEMPOOL FOR DIALUP
Nokia Security GW
Nokia Security GW
Nokia IP650 sec GW
Nokia IP650 sec GW
Nokia Security GW
Soc Classification level 26 © Nokia Siemens Networks
BSC & PCU Functionalities
Base Station Controller (BSC) functions are:
• It is the Radio Resource Manager for BSS• Routes the incoming user and signaling info to MSC & MS• Handles the A-bis and A-interface specific signaling• Handles the related traffic
Packet Control Unit (PCU) functions are:
• Channel access control functions (i.e. access request and grant)• GPRS radio connection establishment and management functions• GPRS RRM functions (like power control, congestion control, broadcast control information)• Data transfer and LLC PDU management:• Coding scheme selection (CS1-4 and MCS1-9)• Dynamic Abis interface management functions• Gb interface management functions, Gb load sharing (uplink) and flow control (downlink)• PCU measurements (statistics)• Network controlled and network assisted MS cell changes
Soc Classification level 27 © Nokia Siemens Networks
BSC3i computer units in 1st Cabinet
900 x 600 x 2000
BSC3i base cabinet BSC3i base cabinet
MCMUMCMUMCMUMCMU OMUOMU
BCSUBCSUBCSUBCSU BCSUBCSU
BCSUBCSUBCSUBCSU BCSUBCSU
•In BSC3i there can be 0, 1, or 2 PCU-B or PCU2-D plug-in units in each BCSU
•Both the PCU-B and PCU2-D hardware plug-in units contain two logical PCUs
•In the BSC2i there can be 0, 1, or 2 PCU1 variants or PCU2-U plug-in units in each BCSU
•The amount and types of the PCU plug-in units can be selected flexibly according to the functionality and traffic handling capacity needs
BCSUBCSU
PCU units
Architecture changes:
10 + 1 BCSU units (5+1 in basic cabinet)
LANU
Ethernet Message Bus (EMB)
Removed units:
MBIF’s
Soc Classification level 28 © Nokia Siemens Networks
PCU2 versus PCU1 capabilitiesPCU capabilitiesVariants --> PCU PCU-S PCU-T PCU-B PCU2-U PCU2-D
BSS 10.5 ED & BSS 11Max BTSs 64 64 64 2*64 N/A N/AMax TRXs 128 128 128 2*128 N/A N/AMax SEGs 64 64 64 2*64 N/A N/AMax Radio TSLs 256 256 256 2*256 N/A N/AMax Abis channels at 16kbps 256 256 256 2*256 N/A N/AMax Gb channels at 64 kbps 31 31 31 2*31 N/A N/A *)
BSS 11.5Max BTSs 64 64 64 2*64 128 2*128Max TRXs 128 128 128 2*128 256 2*256Max SEGs 64 64 64 2*64 64 2*64Max Radio TSLs 128 128 256 2*256 256 2*256Max Abis channels at 16kbps 256 256 256 2*256 256 2*256Max Gb channels at 64 kbps 31 31 31 2*31 31 2*31 *)
number of logical PCU on board 1 1 1 2 1 2BSC type BSCE,
BSC2, BSCi, BSC2i
BSCE, BSC2, BSCi,
BSC2i
BSCE, BSC2, BSCi,
BSC2i
BSC3i BSC2i BSC3i
Note that the max values are not necessary the most optimal ones.
*) 31 TSL for single Gb link limited by ET. The sum of several links up to 32 TSL.
Soc Classification level 29 © Nokia Siemens Networks
(E)GPRS BSS Network Dimensioning and Planning - Content
Preparation for Planning
•Operator’s Business Plan Analysis•# of users with traffic volume
•Services with QoS
•Controlled investment
•Operator’s BSS Network Analysis•Hardware audit
•Software audit
•Feature audit
•Coverage and C/I Estimation
Planning Activities
•Deployment Planning
•Air Interface Capacity Calculations•TSL data rate and multislot usage
•Avail / required capacity calculation
•Connectivity Calculations•CDEF and DAP size
•PCU calculation
•Gb link calculation
• PAPU and SGSN calculation
Soc Classification level 30 © Nokia Siemens Networks
Network AnalysisBusiness Plan
The business plan shows the importance level of (E)GPRS services. – The networks need different setup in case of e.g. background service
requirement without guaranteed bit rate on selected BTSs only compared to the e.g. streaming requirement for the whole network.
Therefore the network planning outcome should be in accordance with the business plan.
Usually the business plan requirements are mainly related to:– Number of users with traffic volume (with density map)
– Services with QoS both on CSW and PSW
– Controlled investment
All the expectations above must be fulfilled to operate successful (E)GPRS services.
Soc Classification level 31 © Nokia Siemens Networks
Network AnalysisBSS Hardware and Software
Both the hardware types and software / feature releases used by the operators must be analyzed to stress the importance of limits in implementation.
BSS Hardware Considerations BSC types with PCU and PCU2 (if any), BTS types (with Baseband units),
TRX capability (mixture of GPRS and EGPRS TRXs)
GSM Feature Considerations MultiBCF and Common BCCH, RF and BB Hopping, FR/DR/HR and AMR,
IUO/IFH
Soc Classification level 32 © Nokia Siemens Networks
Network AnalysisConfiguration and Traffic Figures
The following items should be collected before capacity dimensioning:
• Site configuration (segments with BTS, cells, TRXs)
• Existing traffic figures (CSW and PSW (if any) traffic volume on BTS level with blocking expectations)
• Expected traffic figures with QoS (based on the operators' business plan)
Soc Classification level 33 © Nokia Siemens Networks
Network AnalysisAir Interface
The coverage and interference should be analyzed, because the TSL data rate is defined by coverage and interference as well.
• The signal level and interference level can be analyzed by:– Planning tool plots
– Drive test measurements
– OSS measurements
The RLC/MAC TSL data rate used by the capacity dimensioning can be based on the graphs below:
RLC/MAC Data Rate (FTP Download on 2 TSLs)
0
20
40
60
80
100
120
-65 -70 -75 -80 -85 -90 -95 -100 -105
Signal level (dBm)
kbp
s
No Interference
C/I 25 dB
C/I 20 dB
C/I 15 dB
Soc Classification level 34 © Nokia Siemens Networks
Deployment Plan
The aim behind the preparation of deployment plan:
•Maximize the TSL data rate (RLC/MAC) and multislot usage
•Minimize the impact of PSW services on CSW services (and vice versa)
•Take all the hardware and software considerations into account
•Controlled investment
Most of the networks can be described by few cell/segment options
The analysis of the different options can give exact picture about the network based on:
•Operators’ business plan
•Hardware types, software releases (features and parameters as well)
•Operators’ current network structure and functionality
•Coverage, quality and capacity characteristics of BSS
Soc Classification level 35 © Nokia Siemens Networks
Deployment Plan - Cell / Segment Option Creation
Cell / Segment option examplesLayer strategy BTSs TRXs TSL0 TSL1 TSL2 TSL3 TSL4 TSL5 TSL6 TSL7 PSW terr.
TRX1 BCCH TCH/D TCH/D TCH/D TCH/D TCH/D TCH/D TCH/DTRX2 TCH/F TCH/F TCH/F TCH/F TCH/F TCH/F TCH/F TCH/FTRX3 TCH/F TCH/F TCH/F TCH/F TCH/F TCH/F Default Default (E)GPRS
Layer strategy BTSs TRXs TSL0 TSL1 TSL2 TSL3 TSL4 TSL5 TSL6 TSL7TRX1 CBCCH SDCCH TCH/D TCH/D TCH/D TCH/D TCH/D TCH/DTRX2 TCH/F TCH/F TCH/F TCH/F Default Default Default Dedicated (E)GPRS
Layer2 CSW only BTS2 TRX3 TCH/F TCH/F TCH/F TCH/F TCH/F TCH/F TCH/F TCH/F
Layer strategy BTSs TRXs TSL0 TSL1 TSL2 TSL3 TSL4 TSL5 TSL6 TSL7TRX1 CBCCH SDCCH TCH/D TCH/D TCH/D TCH/D TCH/D TCH/DTRX2 TCH/F TCH/F TCH/F TCH/F TCH/F Default Default Dedicated GPRS
Layer2 CSW, EGPRS BTS2 TRX3 TCH/F TCH/F TCH/F TCH/F Default Default Default Dedicated EGPRS
Layer strategy BTSs TRXs TSL1 TSL2 TSL3 TSL4 TSL5 TSL6 TSL7 TSL8 PSW terr.TRX1 CBCCH SDCCH TCH/F TCH/F Default Default Default Dedicated EGPRSTRX2 TCH/D TCH/D TCH/D TCH/D TCH/D TCH/D TCH/D TCH/DTRX3 TCH/F TCH/F TCH/F TCH/F TCH/F TCH/F TCH/F TCH/FTRX4 TCH/F TCH/F TCH/F TCH/F Default Default Default Dedicated GPRS
Cell / Segment option 2
BTS1CSW, GPRS, EGPRSLayer1Cell / Segment option 1
BTS1
BTS1Cell / Segment option 4
CSW, EGPRS
Cell / Segment option 3
Layer1
Layer1 CSW, GPRS
CSW, GPRSLayer2 BTS2
Layer1 CSW, (E)GPRS BTS1
Cell / segment option creation (PCU1)
•The options can cover most of the cell/segment configurations of the network
•These options can be analyzed in details, so the time consuming cell/segment based analysis is not needed
•All the options are examples and can have different channel configuration
Soc Classification level 36 © Nokia Siemens Networks
Air Interface CapacityAvailable Capacity
The available air interface capacity can be calculated by the following way:
Available air interface capacity for (E)GPRS (TSLs) = Amount_of_TRXs*8 - signaling_RTSLs (KPI: ava_52* + ava_51) – Average CSW traffic (KPI: trf_202) - free_RTSLs (Param.:CSD and CSU)
The air interface capacity (TSLs) is suitable, if it is >= 4, because 4 TSLs are recommended for 4 TSL multislot usage (CDEF=4 TSLs)
(with HMC the CDEF can be 5 TSL, too)
*CDED is not counted by ava_52, therefore ava_51 must be used if CDED is used
Soc Classification level 37 © Nokia Siemens Networks
Connectivity CapacityCDEF Size
Define CDEF for all the BTSs in the BSC– 4 RTSLs are recommended to provide the availability of 4 TSLs
capable MS without territory upgrade (Par.: CDEF) (it can be 5 TSLs if HMC is used)
– If there is low amount of PSW traffic on the cell, then the CDEF can be less than 4 RTSLs (KPI: trf_74c/trf_213c, trf_167/trf_215a Par.: CDEF)
Soc Classification level 38 © Nokia Siemens Networks
Connectivity CapacityDAP Size
Define the # of DAPs and DAP size for all the BCFs in the BSC– The recommendation for DAP size (64 kbps TSL) is DAP size = CDEF
if one BTS/ EDAP configuration is used. If CDEF is less than 4, still 4 TSL DAP size is recommended.
– The recommendation for DAP size (64 kbps TSL) is DAP size = average of CDEFs*1.3 if 2 BTS/ EDAP configuration is used. If average CDEF*1.3 is less than 4, still 4 TSL DAP size is recommended.
– The recommendation for DAP size (64 kbps TSL) is DAP size = average of CDEF*1.5 if 3 BTS/ EDAP configuration is used. If average CDEF*1.5 is less than 4, still 4 TSL DAP size is recommended.
– If DAP size calculation gives less than 4 TSL DAP size the recommendation is still 4 TSL DAP to support 4 RTSL capable MS with MCS9 on all the RTSL
– Make the same calculations for all the required BCFs– Make the same calculations for all the required BSCs
Soc Classification level 39 © Nokia Siemens Networks
Connectivity Calculations# of PCUs
Based on the CDEF and DAP size inputs the # of required PCUs can be calculated
– Count the # of Segments, BTS objects, TRXs in the BSC (100 % utilization is allowed)
– Define the EDAP strategy (one EDAP for the BCF, more than one EDAP for a BCF)
– Calculate the # of EDAPs / PCU (it is recommended to have 1,2,4, or 8 EDAPs/ PCU1; 1-8 EDAPs with PCU2)
– Calculate the # of RTSLs and Abis sub-TSLs related to BSC (70 % utilization is allowed)
– Calculate the # of logical and physical PCUs based on BSC type
– Make the same calculations for all the required BSCs
Soc Classification level 40 © Nokia Siemens Networks
Connectivity CalculationsGb Size
• Calculate the Gb size based on # of EDAPs and size of EDAPs connected to PCU– The recommendation for Gb size is Min_Gb_1 = 1.25*Max_EDAP size– The average traffic from several EDAP can be calculated with k-factor:
Min_Gb_2 = k * Average(EDAP_size_1 to EDAP_size_n)
– The k-factor is selected based on the estimate of the short term traffic distribution among different EDAPs. If no specific information about the distribution is available it is recommended to use the default values for k.
Soc Classification level 41 © Nokia Siemens Networks
Connectivity CalculationsGb Size
– The recommendation for Gb link size is Max(Min_Gb_1, Min_Gb_2)
– The final Gb link size might need to be adjusted to fit to available E1/T1 links.
• Define the Gb size connected to all the PCUs in one BSC• Define the Gb size for all the required BSCs
Soc Classification level 42 © Nokia Siemens Networks
Connectivity in SGSN (SG5)
The following limits must be taken into account:
• 1024 PCUs can be connected to SGSN (with 16 PAPU)
• 64 PCUs can be connected to PAPU
• 3072 Gb links can be connected to SGSN (with 16 PAPU)
• 192 Gb links can be connected to PAPU
• 120 E1s can be connected to SGSN (with 16 PAPU)
Soc Classification level 43 © Nokia Siemens Networks
(E)GPRS BSS Network Optimization
GSM Network Optimization*•Coverage maximization
•Interference reduction
•Capacity optimization (air interface and connectivity)* Not part of this training
(E)GPRS Network Optimization•Signaling capacity & resource allocation improvement
•Data Rate
•Connectivity Capacity (MS-SGSN)
•TSL data rate improvement and multislot usage maximization (BSS)
•E2E data rate (applications)
•Mobility improvement
Soc Classification level 44 © Nokia Siemens Networks
GSM Network Optimization
The optimal GSM network from PSW services point of view has: As high signal level as possible• It means that even the indoor signal level should be high enough to have MCS9 for getting the highest
data rate on RLC/MAC layer.As low interference as possible • The aim of having high C/I is to avoid throughput reduction based on interference. Enough capacity• Enough BSS hardware capacity (interface and connectivity) is needed to provide the required capacity for
PSW services in time. Both CSW and PSW traffic management should be harmonized with the layer structure and long term plans.
As few cell re-selection as possible• The dominant cell coverage is important to avoid unnecessary cell-reselections in mobility. The prudent
PCU allocation can help to reduce the inter PCU cell reselections. • Dominant cell structure can help to maximize the signal level and reduce the interference, too.Features• All the features should be used which can improve the PSW service coverage, capacity and quality in
general.
The GSM network is the physical layer of (E)GPRS, so the optimization of GSM network can improve the performance of (E)GPRS, too. Pls. refer to GSM BSSPAR and RANOP
Soc Classification level 45 © Nokia Siemens Networks
(E)GPRS Network Optimization
Signaling Capacity & Resource Allocation improvement• Signaling
– RF, TRXSIG, BCSU, PCU, MM and SM signaling
• Resource Allocation– Cell (re)-selection, BTS selection, scheduling
Data Rate• Connectivity Capacity (MS-SGSN)
– CDEF size, DAP size, # of PCUs and BCF allocation among PCUs, Gb size and PAPU (SGSN)
• TSL data rate improvement and multi-slot usage maximization (BSS)– TSL utilization, TBF release delay and BS_CV_MAX, LA, UL PC, multiplexing, multislot usage
• E2E data rate (applications)– Flow control, SGSN, TCP/IP, applications
Mobility improvement (outage reduction)• PCU rebalancing• LA/RA design• NACC
Soc Classification level 46 © Nokia Siemens Networks
Links
Details about NetAct Optimizerhttp://domino.inside.nokiasiemensnetworks.com/NET/OSS/bookshlf.nsf/vwDocsByCat1All2?OpenView&Start=1&Count=1000&Expand=36
Optimization Guidelineshttps://sharenet-ims.inside.nokiasiemensnetworks.com/livelink/livelink?func=ll&objId=358173597&objAction=Browse&viewType=1
(E)GPRS Networks – Dimensioning Quick Guideshttps://sharenet-ims.inside.nokiasiemensnetworks.com/Open/362637122
(E)GPRS Networks – Dimensioning and Planning Guidelineshttps://sharenet-ims.inside.nokiasiemensnetworks.com/Open/362642110
(E)GPRS Networks – Optimization Guidelineshttps://sharenet-ims.inside.nokiasiemensnetworks.com/Open/362650970
(E)GPRS Networks – Toolshttps://sharenet-ims.inside.nokiasiemensnetworks.com/Open/362631176