Commercial-in-Confidence UMTS Network Dimensioning UMTS Network Dimensioning UMTS network dimensioning
Feb 17, 2016
Commercial-in-Confidence
UMTS Network DimensioningUMTS Network Dimensioning
UMTS network dimensioning
Commercial-in-Confidence
ContentsContents• Network Dimensioning?• Spreadsheet dimensioning.• Benchmark planning• Graphical dimensioning.
UMTS network dimensioning
Commercial-in-Confidence
Network Dimensioning (1)Network Dimensioning (1)• Network dimensioning is carried out at the start a project.• It is a process through which an initial estimate of the
amount of network equipment and possible configurations are determined.
• The inputs to the process can be:! Spectrum availability.! License conditions.! Equipment characteristics.! Link budget.! Geographic/Demographic data.! Market projections
UMTS network dimensioning
Commercial-in-Confidence
Network Dimensioning (2)Network Dimensioning (2)• The outputs of network dimensioning are used for:
! Budgetary purposes." Negotiations with vendors." Manpower resource estimations." Business plans." Network rollout plans." Negotiations with financial backers.
! License applications." Auction price." Spectrum requirement / license preference.
! Implementation." Rollout Timetable and Resource Requirements" Coverage strategy.
UMTS network dimensioning
Commercial-in-Confidence
The Network Dimensioning ProcessThe Network Dimensioning Process
CoverageRequirements
CapacityRequirements
QualityRequirements
Dimensioning
Rough estimateof Number
of Base Stations
Rough estimateof Configurationof Base Stations
Area Type&
Radio Propagation Data
UMTS network dimensioning
Commercial-in-Confidence
Network Dimensioning MethodsNetwork Dimensioning Methods• There are two main methods of dimensioning a network.
! Spreadsheet based. ! Benchmark planning - Dart throwing!
• Many companies use a sophisticated spreadsheet approach to model the combination of network coverage and capacity.
• Alternatively it is possible to dimension the network by benchmark, or first-pass, planning
• AIRCOM are currently developing an GIS based dimensioning tool to combine the advantages of these two methods
• This section looks at all three approaches.
UMTS network dimensioning
Commercial-in-Confidence
Spreadsheet DimensioningSpreadsheet Dimensioning• We shall look at 4 scenarios
! A simple coverage driven spreadsheet! A simple capacity driven spreadsheet ! A simple combined approach! A complex coverage vs capacity tradeoff planning tool
UMTS network dimensioning
Commercial-in-Confidence
• Link budgets are used to calculate max path losses.• Path loss is converted into cell radii for different environments.• Cell radii are used to estimate typical site coverage areas.• Estimate the average site coverage area for each environment.• No. sites (per environment) = Environment Area
• Add together the number of sites per environment required for each zone.
• Assumptions on cell loading and services offered are made in the link budget process.
Spreadsheet Dimensioning Spreadsheet Dimensioning -- Simple Simple Coverage Coverage
Average Site Coverage Area___________________
UMTS network dimensioning
Commercial-in-Confidence
Spreadsheet Dimensioning Spreadsheet Dimensioning -- Simple Simple Coverage (2)Coverage (2)
Site ParametersType 1 Type 2 Type 3
Frequency 2000 2000 2000 MHzTransmitter Height 25 15 30 mReceiver Height 1.5 1.5 1.5 mSite Location urban suburban ruralNo. BT's 3 3 1
MAPL 155 155 155 dBReliability in coverage area 95 95 95 %Log Normal SD (Terrain) 5 5 5 dBLog Normal fade margin (Terrain) 18 25 8 dBMAPL w / Log Norm. fade margin 137 130 147 dB
Typical Cell Radii for 150MHz < f < 1500MHzurban 1.03 0.55 2.13 kmurban large 1.03 0.55 2.12 kmsuburban 2.26 1.18 4.73 kmrural 4.38 2.22 9.25 kmopen 8.34 4.12 17.78 km
Typical Cell AreasUrban 3.33 0.96 14.23 km2Urban large 3.31 0.95 14.14 km2Suburban 16.11 4.35 70.38 km2Rural 60.31 15.45 268.64 km2Open 218.73 53.30 993.02 km2
Geographic DataCoverage Area 151207 km2Urban Area 5000 km2Urban Large Area km2Suburban Area 20632 km2Rural Area 111156 km2Open Area km2
Site DataNo. of sites 1500 4747 414No. of BT's 4499 14240 414
Total Sites 6660Total BT 19153
UMTS network dimensioning
Commercial-in-Confidence
Spreadsheet Dimensioning Spreadsheet Dimensioning -- Simple Simple CapacityCapacity
• Given an estimate of the traffic profile per subscriber we can calculate the offered traffic per km2 per environment
• Given the capacity of a cell we can estimate the average site capacity area per environment
! Note we may wish to take factors such the uneven distribution of traffic between sectors into account
• No. sites (per environment) = Environment Area
• Add together the number of sites required per environment for each zone.
Average Site Capacity Area___________________
UMTS network dimensioning
Commercial-in-Confidence
Spreadsheet analysis Spreadsheet analysis -- Simple Simple Combined Coverage/Capacity ApproachCombined Coverage/Capacity Approach• Given the simple analysis that we have carried out above
for coverage and capacity we could:! Compare the number of sites required per zone derived from the
capacity approach and the coverage approach! This tells us if the zone is:
" Coverage Constrained" Capacity Constrained
! The output of the dimensioning would be the largest number of sites per zone
UMTS network dimensioning
Commercial-in-Confidence
• The above approach is ‘acceptable’ for GSM• Unfortunately the coverage and capacity relationship in UMTS is
much closer• Typically spreadsheet dimensioning tools for UMTS take a combined
iterative approach:! The range of a cell is calculated from a link budget containing an
interference margin calculated from the loading! The area covered by the cell is then calculated from the range! The traffic captured by a cell is then calculated from the area and
subscriber density! The loading of the cell is then calculated from the captured traffic! And then the link budget is recalculated from the new loading
• The loop is repeated until convergence is reached
Dimensioning for UMTSDimensioning for UMTSUMTS network dimensioning
Commercial-in-Confidence
Dimensioning Tools for UMTSDimensioning Tools for UMTS• However it isn’t really that ‘easy’, problems can occur with:
! Microcells! Road coverage and Urban coverage overlapping! Transmission dimensioning
• The spreadsheets tend to get a little bit complicated...• A number of commercially available tools are available on
the market to dimension UMTS networks
UMTS network dimensioning
Commercial-in-Confidence
Dimensioning by planningDimensioning by planning• However the drawback with the ‘spreadsheet’ approach is that it does
not give the user a very good visualisation of what the results mean• An alternative approach is to create a ‘first pass’ or ‘benchmark’ plan• The planning for this would be similar to nominal planning as we will
discuss later! Create a link budget and propagation model! Place sites and predict! Check for broken loading assumptions
• Not so much effort should go into the plan as nominal planning as it is expected to be rough - not the foundation for the network
UMTS network dimensioning
Commercial-in-Confidence
Graphical Dimensioning ToolsGraphical Dimensioning Tools• Aircom’s 3G contains a graphical dimensioning tool • This allows you to quickly estimate and visualise the number of sites
required in a new network.• Currently on the first release - more features will be added.
UMTS network dimensioning
Commercial-in-Confidence
Create Terminal TypeCreate Terminal Type• Create a 3g terminal type.• Allocate 1000 terminals• Spread terminals according to
the weights listed here.
Clutter Type WeightUnclassified 0
Urban 500Suburban Residential 20
Village 10Isolated Dwellings 1
Open Rural 1Woodland Forest 2Park Recreational 5
Industry 10Water 0Airport 5
Open in urban 30Agricultural land 1
Pylons 1Sea 0
Rivers 0
UMTS network dimensioning
Commercial-in-Confidence
Spread TerminalsSpread Terminals• Use the traffic wizard to spread
the terminals over the island.• The resultant raster shows the
the terminal density.
UMTS network dimensioning
Commercial-in-Confidence
Define Default SitesDefine Default Sites• Click on the button.
• Enter! Cell Radius = 4000m! Overloaded threshold = 800kb/s! Underloaded threshold = 300kb/s
UMTS network dimensioning
Commercial-in-Confidence
Position First SitesPosition First Sites• Select “3G Dimensioning Sites”
in the 2D window display list.• Click on the button.
• Drag a box around the island with the left hand mouse button.
• Click in the box with the right hand mouse and select:
! “Fill Rectangle with Correctly Loaded Dimensional Sites…”
• The box will be filled with a grid of sites of the defined radius.
UMTS network dimensioning
Commercial-in-Confidence
Split Overloaded CellsSplit Overloaded Cells• The “Calculation Parameter”
window will appear.• Select the desired terminal type.• Enter the mean data rate per
terminal.• Confirm other settings.• “Customize” button is disabled
in this version.• Click “Calculate”.• Overloaded cells will be
sectorised and then split until convergence is reached.
UMTS network dimensioning
Commercial-in-Confidence
Result Result -- Dimensioned NetworkDimensioned NetworkUMTS network dimensioning