ASSET3g Technical Reference Guide

ASSET3g Technical Reference Guide

Version 5.1

Copyright 2006 AIRCOM International Ltd All rights reserved

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ASSET3g Technical Reference Guide Page i Version 5.1

Contents Appendix A Array Descriptions

Arrays (Simulator) 1 Pathloss Arrays 3 Pilot Coverage Arrays 3 Handover Arrays 6 Uplink Noise Arrays 7 Downlink Noise Arrays 7 Uplink Coverage Arrays 8 Downlink Coverage Arrays 9 Coverage Balance Arrays 10 Soft Blocking Arrays 10 Hard Blocking Arrays 11 HSDPA Arrays 12 All Servers Array 14

Arrays (5.0 Simulator) 15 3g Service Arrays (5.0 Simulator) 15 3g Carrier Arrays (5.0 Simulator) 23 GSM Arrays (5.0 Simulator) 27

2g and 2.5g (Non-Sim) Arrays 29 Coverage and Interference Arrays (2g + 2.5g) (Non-Sim) 29

Appendix B 2g and 2.5g Algorithms Interference Table Algorithm 39 Interference and Connection Array Calculations 40

Worst Connection Array Calculation Method 41 Average Connection Array Calculation Method 42 Worst Interferer Array Calculation Method 43 Total Interference Array Calculation Method 43 Table of Default C/I BER Conversion Values 44

Frequency Hopping Algorithms 45 Synthesised Hopping Algorithm 46

Non-Frequency Hopping Algorithms 47 Automatic Frequency Planning (ILSA) 48

The Cost Function of the ILSA Algorithm 48 MAIO Planning Cost Function 49 GPRS and HSCSD Capacity Calculations 50

TRX Requirement - Circuit Switched Traffic and HSCSD 50 TRX Requirement - Circuit Switched, HSCSD and GPRS Traffic 50 Grade of Service and Data Rate 51 Channel Occupation Table 52

FCC Calculations 53 Frequency Calculations 54

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Appendix C UMTS Algorithms Notation for UMTS 58 List of Principal Symbols for UMTS 58 UMTS Basic Formulae 60 UMTS Uplink Noise Rise 61 UMTS Uplink Load 61 UMTS Frequency Re-Use Efficiency 61 UMTS Air Interface and User Bitrates 61 UMTS Shadow Fade Modelling 62 UMTS Power Control Error Modelling 62 UMTS Service Activity Modelling 63 UMTS Activity Factor Calculation For Packet Services (Web Model) 64 UMTS Transmit/Receive Diversity Modelling 64 UMTS Terminal Speed Modelling 65 UMTS Overview of a Snapshot 65

UMTS Initialisation of Terminals 66 Initialisation of System Powers and Resource Usage in UMTS 66 UMTS Iterations 66 Gathering of Results in UMTS 68

UMTS Scenario Prioritisation 68 UMTS Connection Evaluation 69

Production of a Candidate Active Set in UMTS 69 UMTS Uplink Evaluation 70 UMTS Downlink Evaluation 72

UMTS Blocking Probability 73 Calculation of Blocking Probability in the Blocking Report for UMTS 73 Blocking Probability and Failure Rate for UMTS 74 UMTS Coverage Probability Array in the Map View 75

Appendix D CDMA2000 Algorithms CDMA2000 Notation 78 List of Principal Symbols for CDMA2000 78 CDMA2000 Basic Formulae 80 CDMA2000 Uplink Noise Rise 81 CDMA2000 Uplink Load 81 CDMA2000 Frequency Re-Use Efficiency 81 CDMA2000 Air Interface and User Bitrates 82 CDMA2000 Shadow Fade Modelling 82 CDMA2000 Power Control Error Modelling 83 CDMA2000 Service Activity Modelling 83

ASSET3g Technical Reference Guide Page iii Version 5.1

CDMA2000 Activity Factor Calculation For Packet Services (Web Model) 84 CDMA2000 Transmit/Receive Diversity Modelling 85 CDMA2000 Terminal Speed Modelling 85 PN Code Assignment Algorithm for CDMA2000 86

Difficulty Factor for CDMA2000 86 Best PN Code to Assign for CDMA2000 86 Quality Factor for CDMA2000 86

CDMA2000 Overview of a Snapshot 87 CDMA2000 Initialisation of Terminals 87 Initialisation of System Powers and Resource Usage in CDMA2000 88 CDMA2000 Iterations 88 Gathering Of Results in CDMA2000 89

CDMA2000 Scenario Prioritisation 90 CDMA2000 Connection Evaluation 91

Production of a Candidate Active Set in CDMA2000 91 CDMA2000 Uplink Evaluation 92

Calculation of Equivalent Control Overhead Factors for CDMA2000 93 Uplink RC1 - RC2 94 Uplink RC3 - RC6 When Using a Supplemental Bearer 95 Uplink RC3 - RC6 When Not Using a Supplemental Bearer 96 Downlink RC1 - RC2 97 Downlink RC3 - RC10 98

CDMA2000 Blocking Probability 99 Calculation of Blocking Probability in the Blocking Report for CDMA2000 99 CDMA2000 Blocking Probability and Failure Rate 100 CDMA2000 Coverage Probability Array in the Map View Window 101

CDMA2000 Downlink Evaluation 102

Appendix E HDR Algorithms HDR Notation 106 List of Principal Symbols for HDR 106 HDR Basic Formulae 108 HDR Uplink Noise Rise 108 HDR Uplink Load 109 HDR Frequency Re-Use Efficiency 109 HDR Air Interface and User Bitrates 109 HDR Shadow Fade Modelling 109 HDR Power Control Error Modelling 110 HDR Service Activity Modelling 111 HDR Transmit/Receive Diversity Modelling 111 HDR Terminal Speed Modelling 111 Overview of a HDR Snapshot 112

HDR Initialisation of Terminals 112 HDR Initialisation of System Powers 112 HDR Iterations 113

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Gathering of Results for HDR 114 Scenario Prioritisation for HDR 115 HDR Connection Evaluation 115

HDR Uplink Evaluation 116 HDR Downlink Evaluation 117

Calculation of Uplink Equivalent Control Overhead Factor for HDR 118 HDR Coverage Probability and Blocking 119

HDR Coverage Probability Array in the Map View Window 119 HDR Blocking Probability and Failure Rate 119

About the HDR Quality of Service Algorithm 120 HDR Outline 120 IP Packet Transmission Time for HDR 121 IP Packet Queueing Delay for HDR 122 Throughput for HDR 124

Appendix F Packet Quality of Service Algorithms Simulation Inputs for QoS Analysis 126

Preliminary Tests 126 Traffic Generator for QoS Analysis 126

Matching Generated Traffic to the Simulator's Mean Number of Served Users 127 WWW Traffic Model 128 Packet Model 129 About the Code Schemes for GPRS 130 QoS Profiles for GPRS 131

Time Simulator for QoS Analysis 134 System Model for QoS Analysis 134 Simulation Model for QoS Analysis 134

Results of QoS Analysis 136 Confidence Interval Half Width 136 Simulation Duration 137 Delay and Cumulative Delay Probability Distributions 138 Mean and Standard Deviations of the Queuing Delays 139 95th Percentile Delay 139 Mean Transmission Time 139 Mean Retransmission Delay 140

References 140

Glossary of Terms

Index

ASSET3g Technical Reference Guide Page 1 Version 5.1

Array Descriptions This section describes the different types of array available in ASSET3g. The ranges of arrays available may vary according to which technology you are using, which licences you have, and which processes you have chosen to run.

The following types of array are described:

Arrays (Simulator) 3g Service arrays (5.0 Simulator) 3g Carrier arrays (5.0 Simulator) GSM arrays (5.0 Simulator) Coverage/Interference arrays (2g, 2.5g and LMU) (Non-Sim) For information on creating and displaying arrays, see Using Arrays in the ASSET3g User Reference Guide.

In This Section Arrays (Simulator) Arrays (5.0 Simulator) 2g and 2.5g (Non-Sim) Arrays

Arrays (Simulator) This is an overview of the arrays generated by the Simulator in ASSET3g.

All these arrays are produced on a per carrier basis.

Most of them have a dependency on terminal type because body loss and terminal antenna gain are always included in the link budget.

Many of them depend on whether the terminal is considered to be indoor or outdoor. Indoor arrays use the in-building parameters for the clutter type at each pixel (that is, indoor loss and indoor shadow fading standard deviation). Indoor terminals are always taken to be slow moving.

A P P E N D I X A

ASSET3g Technical Reference Guide Version 5.1

Coverage arrays can be displayed even if no snapshots have been run, but you should note that in these circumstances the arrays represent coverage in an unloaded network. To obtain coverage arrays for a loaded network, you must run some snapshots. The key purpose of running snapshots is to provide measures of system load.

Arrays for coverage tend to have a weak dependence on the number of snapshots run, and the arrays change little after a relatively small number of snapshots have been performed (10s of snapshots in most cases). This is because only a small number of snapshots are needed to get an idea of the average noise rise and average DL traffic power on each cell.

Arrays for hard or soft blocking probabilities have a strong dependence on the number of snapshots run. This is because blocking is evaluated by reporting the proportion of snapshots that would block further connections. For example, if only 1 snapshot has been run, then all blocking probabilities will be either 0% or 100%. If 5 snapshots have been run then all blocking probabilities will belong to the set {0%, 20%, 40%, 60%, 80%, 100%}.

Here is an example of the arrays you can generate on the Map View when using the Simulator:

Example of the Simulator arrays appearing in the Map View Data Types


Pathloss Arrays

DL Loss

Dependencies: Terminal, Carrier, Indoor

The lowest downlink loss. Represents average values and is therefore calculated with fades of 0dB.

Nth DL Loss


The Nth lowest downlink loss. Represents average values and is therefore calculated with fades of 0dB.

Pilot Coverage Arrays These arrays all provide information on pilot levels and coverage probabilities. There are 3 types of quantity relating to the pilot (RSCP, Ec/Io, SIR) and there are arrays for all of these.

Best DL Cell by RSCP

Dependencies: Carrier

This is the cell that provides the highest RSCP for the terminal.

Best RSCP

Dependencies: Carrier, Indoor

The highest RSCP level. Represents average values and is therefore calculated with fades of 0dB.

Nth Best RSCP

Dependencies: Carrier, Indoor

The Nth highest RSCP level. Represents average values and is therefore calculated with fades of 0dB.

RSCP Coverage Probability


This is the probability that the Best DL Cell (by RSCP) satisfies the RSCP requirement specified on the terminal type. This probability depends on the standard deviation of shadow fading for the clutter type at the pixel. If this standard deviation has been set to zero, then there are only three possible coverage probabilities: 0% if the requirement is not satisfied, 50% if the requirement is satisfied exactly, and 100% if the requirement is exceeded.


RSCP Coverage OK


This is a thresholded version of the RSCP Coverage Probability array and has just 2 values (Yes/No). It has the advantage of being quicker to calculate than the RSCP Coverage Probability array. A value of Yes means that the RSCP coverage probability meets the coverage reliability level specified in the Sim Display Settings tab of the Array Settings dialog box.

Number of RSCP OK


This is the number of covering cells with a satisfactory RSCP. A cell is counted as having a satisfactory RSCP if its RSCP coverage probability meets the coverage reliability level specified in the Sim Display Settings tab of the Array Settings dialog box.

Pilot Ec/Io & Nth Best Pilot Ec/Io


These are the highest (and Nth highest) Ec/Io values. They represent average values and are therefore calculated with fades of 0dB.

Pilot Ec/Io Coverage Probability


This is the probability that the Best DL Cell (by RSCP) satisfies the Ec/Io requirement specified on the terminal type. This probability depends on the standard deviation of shadow fading for the clutter type at the pixel. If this standard deviation has been set to zero, then there are only three possible coverage probabilities: 0% if the requirement is not satisfied, 50% if the requirement is satisfied exactly, and 100% if the requirement is exceeded.

Pilot Ec/Io Coverage OK


This is a thresholded version of the Pilot Ec/Io Coverage Probability array and has just 2 values (Yes/No). It has the advantage of being quicker to calculate than the Pilot Ec/Io Coverage Probability array. A value of Yes means that the pilot Ec/Io coverage probability meets the coverage reliability level specified in the Sim Display

Settings tab of the Array Settings dialog box.


Number of Pilot Ec/Io OK


This is the number of covering cells with a satisfactory pilot Ec/Io. A cell is considered as having a satisfactory pilot Ec/Io if its pilot Ec/Io coverage probability meets the coverage reliability level specified in the Sim Display Settings tab of the Array Settings dialog box.

Pilot SIR


This is the best Pilot SIR value. It represents an average value and is therefore calculated with fades of 0dB.

Pilot SIR Coverage Probability


This is the probability that the Best DL Cell (by RSCP) satisfies the pilot SIR requirement specified on the terminal type. This probability depends on the standard deviation of shadow fading for the clutter type at the pixel. If this standard deviation has been set to zero, then there are only three possible coverage probabilities: 0% if the requirement is not satisfied, 50% if the requirement is satisfied exactly, and 100% if the requirement is exceeded.

Pilot SIR Coverage OK


This is a thresholded version of the Pilot SIR Coverage Probability array and has just 2 values (Yes/No). It has the advantage of being quicker to calculate than the Pilot SIR Coverage Probability array. A value of Yes means that the pilot SIR coverage probability meets the coverage reliability level specified in the Sim Display Settings tab of the Array Settings dialog box.

Number of Pilot SIR OK


This is the number of covering cells with a satisfactory pilot SIR. A cell is considered as having a satisfactory pilot SIR if its pilot SIR coverage probability meets the coverage reliability level specified in the Sim Display Settings tab of the Array Settings dialog box.


Handover Arrays The aim of the following arrays is to provide the planner with an idea of potential handover areas, and to indicate areas of pilot pollution. All arrays are based on mean Pilot Ec/Io levels calculated with fades of 0dB.

Available Soft/Softer Cells


This is the number of suitable HO candidates for the Best DL Cell (by RSCP). If the Ec/Io level of the best DL cell is below the Ec/Io requirement on the terminal type, then no result is given. Otherwise all the other cells are checked to see if their pilot Ec/Io levels make them suitable HO candidates.

Available Soft Cells


This is the number of suitable soft HO candidates for the Best DL Cell (by RSCP). If the Ec/Io level of the best DL cell is below the Ec/Io requirement on the terminal type, then no result is given. Otherwise all the other cells (on different sites to the best cell) are checked to see if their pilot Ec/Io levels make them suitable HO candidates.

Available Softer Cells


This is the number of suitable softer HO candidates for the Best DL Cell (by RSCP). If the Ec/Io level of the best DL cell is below the Ec/Io requirement on the terminal type, then no result is given. Otherwise all the other cells (on the same site as the best cell) are checked to see if their pilot Ec/Io levels make them suitable HO candidates.

Active Set Size


This is the potential size of the active set. It is related to the Available Soft/Softer Cells array by: Active Set Size = min (1 + Available Soft/Softer Cells, Max Active Set Size).

Pilot Polluters


If the Pilot Pollution Threshold specified in the Simulation Wizard is XdB then:

For UMTS, the number of pilot polluters at a location is the number of cells that are not in the active set, but provide an Ec/Io level within XdB of the best Ec/Io in the active set. Therefore the pilot pollution threshold in UMTS is a relative quantity.

A typical threshold value for UMTS is 6dB.

For CDMA2000, the number of pilot polluters at a location is the number of cells that are not in the active set, but provide an Ec/Io level higher than XdB. Therefore the pilot pollution threshold in CDMA2000 is an absolute quantity.

A typical threshold value for CDMA2000 is -15dB.


Uplink Noise Arrays

UL Load


This is the uplink cell load of the Best DL Cell (by RSCP). Note that for OTSR cells, there can be a different uplink load on each antenna used by the cell (just as in the uplink simulation reports for OTSR cells).

UL FRE


This is the uplink frequency re-use efficiency of the Best DL Cell (by RSCP). Note that for OTSR cells, there can be a different uplink FRE on each antenna used by the cell (just as in the uplink simulation reports for OTSR cells).

Downlink Noise Arrays

DL Io


This is the total downlink power spectral density. It represents an average value and is therefore calculated with fades of 0dB.

DL Iother/Iown


This is the ratio of downlink power received from other cells, to downlink power received from own cell, where own cell is the Best DL Cell (by RSCP).

DL FRE


This is the downlink frequency re-use efficiency at a pixel and it is related to DL Iother/Iown as follows:

DL FRE = 1 / ( 1 + Iother/Iown ).


Uplink Coverage Arrays Uplink coverage arrays are available for each bearer at different speeds.

Best UL Cell

Dependencies: Terminal, Carrier, Indoor, Service, UL Bearer, Speed

This is the cell requiring the minimum uplink transmit power. For UMTS bearers, the only real dependence is on the carrier used. However for CDMA2000 bearers, the Best UL Cell must have an RC type that is supported by the terminal type.

UL Eb/No Margin


This is how much we exceed the uplink Eb/No requirement by on the Best UL Cell, assuming the terminal transmits at full power.

UL Coverage Probability


This is the probability of satisfying the uplink bearer Eb/No requirement on the Best UL Cell, assuming the terminal transmits at full power. This probability depends on the standard deviation of shadow fading for the clutter type at the pixel. If this standard deviation has been set to zero, then there are only three possible coverage probabilities: 0% if the requirement is not satisfied, 50% if the requirement is satisfied exactly, and 100% if the requirement is exceeded.

UL Coverage Probability OK


This is a thresholded version of the UL Coverage Probability array and has just 2 values (Yes/No). It has the advantage of being quicker to calculate than the UL Coverage Probability array. A value of Yes means that the uplink coverage probability meets the coverage reliability level specified in the Sim Display Settings tab of the Array Settings dialog box.

Achievable UL Bearer

Dependencies: Terminal, Carrier, Indoor, Service, Speed

The purpose of this array is to provide a composite coverage plot for the uplink bearers of a service. The array shows the highest priority uplink bearer with acceptable uplink coverage, that is, with UL Coverage Probability meeting the coverage reliability level specified in the Sim Display Settings tab of the Array Settings dialog box.


Downlink Coverage Arrays Downlink coverage arrays are available for each bearer at different speeds.

Best DL Cell

Dependencies: Terminal, Carrier, Indoor, Service, DL Bearer, Speed

This is the cell requiring the minimum downlink transmit power. For UMTS bearers, the only real dependence is on the carrier used, and so this array is exactly the same as the Best DL cell by RSCP. However for CDMA2000 bearers, the Best DL Cell must have an RC type that is supported by the terminal type.

DL Eb/No Margin


This is how much the downlink Eb/No requirement has been exceeded, assuming that the link powers of cells in the active set are at maximum allowed levels.

DL Coverage Probability


This is the probability of satisfying the downlink bearer Eb/No requirement, assuming that the link powers of cells in the active set are at maximum allowed levels. This probability depends on the standard deviation of shadow fading for the clutter type at the pixel. If this standard deviation has been set to zero, then there are only three possible coverage probabilities: 0% if the requirement is not satisfied, 50% if the requirement is satisfied exactly, and 100% if the requirement is exceeded.

DL Coverage Probability OK


This is a thresholded version of the DL Coverage Probability array and has just 2 values (Yes/No). It has the advantage of being quicker to calculate than the DL Coverage Probability array. A value of Yes means that the downlink coverage probability meets the coverage reliability level specified in the Sim Display Settings tab of the Array Settings dialog box.

Achievable DL Bearer


The purpose of this array is to provide a composite coverage plot for the downlink bearers of a service. The array shows the highest priority downlink bearer with acceptable downlink coverage, that is, with DL Coverage Probability meeting the coverage reliability level specified in the Sim Display Settings tab of the Array Settings dialog box.


Coverage Balance Arrays

Coverage Balance


The purpose of this array is to provide a composite uplink/downlink coverage plot for a service. The uplink is deemed to have coverage if any of the uplink bearers on the service have UL Coverage Probability meeting the coverage reliability level specified in the Sim Display Settings tab of the Array Settings dialog box. Similarly, the downlink is deemed to have coverage if any of the downlink bearers on the service have DL Coverage Probability meeting the coverage reliability level specified in the Sim Display Settings tab of the Array Settings dialog box.

Soft Blocking Arrays

UL Soft Blocking Probability


This is the probability of uplink soft blocking on the Best UL Cell. Uplink soft blocking occurs if an additional connection with the uplink bearer would cause the noise rise limit to be exceeded. The uplink soft blocking probability is determined by examining the proportion of snapshots that would block a connection with the uplink bearer in this way. Note that for OTSR cells, the noise rise is measured on a per antenna basis (as in the simulation reports), so the soft blocking probability depends on the antenna that covers the pixel.

DL Soft Blocking Probability


This is the probability of downlink soft blocking on the Best DL Cell. Downlink soft blocking occurs if an additional connection with the downlink bearer requires more power than is available on the cell. The downlink soft blocking probability is determined by examining the proportion of snapshots that would block a connection with the downlink bearer in this way.


Hard Blocking Arrays There a two types of hard blocking arrays for each uplink and downlink resource type. The exception is the HSDPA resource type used to represent HSDPA codes. This does not have a primary blocking array because there are no primary limits for HSDPA codes.

Hard Blocking Probability

Dependencies: Terminal, Carrier, Indoor, Service, Bearer, Speed

This is the probability of hard blocking on the Best DL Cell because of lack of resources. This type of blocking occurs if an additional connection with the bearer requires more resources than are available. The blocking probability is determined by examining the proportion of snapshots that would block a connection with the bearer in this way.

Hard Blocking Probability Primary

Dependencies: Terminal, Carrier, Indoor, Service, Bearer, Speed

This is the probability of hard blocking on the Best DL Cell because of lack of primary resources. This type of blocking occurs if an additional connection with the bearer requires more primary resources than are available. The blocking probability is determined by examining the proportion of snapshots that would block a connection with the bearer in this way.


HSDPA Arrays

HSDPA - Best DL Cell by SINR


This is the cell that provides the highest SINR level for the terminal.

HSDPA - SINR


This is the highest SINR level. It represents an average value and is therefore calculated with fades of 0dB.

HSDPA - DL Eb/No Margin

Dependencies: Terminal, Carrier, Indoor, Service, HSDPA Bearer, Speed

This is the extent to which the Eb/No requirement of the HSDPA bearer is exceeded. The cell of interest is chosen by examining the SINR levels of cells that support the HSDPA bearer, and choosing the cell with the largest level.

HSDPA - DL Coverage Probability


This is the probability of satisfying the Eb/No requirement of the HSDPA bearer. The cell of interest is chosen by examining the SINR levels of cells that support the HSDPA bearer, and choosing the cell with the largest level. The probability depends on the standard deviation of shadow fading for the clutter type at the pixel. If this standard deviation has been set to zero, then there are only three possible coverage probabilities: 0% if the requirement is not satisfied, 50% if the requirement is satisfied exactly, and 100% if the requirement is exceeded.

HSDPA - DL Coverage Probability OK


This is a thresholded version of the HSDPA - DL Coverage Probability array and has just 2 values (Yes/No). It has the advantage of being quicker to calculate than the HSDPA - DL Coverage Probability array. A value of Yes means that the coverage probability meets the coverage reliability level specified in the Sim Display Settings tab of the Array Settings dialog box.

HSDPA - Achievable DL Bearer


The purpose of this array is to provide a composite coverage plot for the HSDPA bearers of a service. The array shows the highest priority HSDPA bearer with acceptable coverage. i.e. with HSDPA - DL Coverage Probability meeting the coverage reliability level specified in the Sim Display Settings tab of the Array Settings dialog box.


HSDPA - Offered Load

Dependencies: Carrier,

This is the offered HSDPA load on the Best DL Cell by SINR. Note that the offered load is calculated for each HSDPA resource pool in the network. Therefore, if the HSDPA resources have been pooled on a site, all HSDPA cells on that site will show the same offered load.

HSDPA - Effective Service Rate (Unloaded)


This is the bitrate that the user experiences at a location when there is no queuing delay on the cell. It is calculated by multiplying the bitrate of the HSDPA - Achievable DL Bearer by its activity factor.

HSDPA - Effective Service Rate (Loaded)


This is the bitrate that the user experiences at a location when there is queuing delay on the cell. The rate drops to zero as the HSDPA load on the cell approaches 100%.

HSDPA - Effective Cell Service Rate (Unloaded)

Dependencies: Carrier, Service

This is the total amount of data in a service session (bits) divided by the mean service time per user on the cell (seconds), assuming there is no queuing delay.

HSDPA - Effective Cell Service Rate (Loaded)

Dependencies: Carrier, Service

This is similar to the HSDPA - Effective Cell Service Rate (Unloaded) array, except that the mean service time per user on the cell is increased because of queuing delay. As the offered HSDPA load on the cell approaches 100%, the queuing delay approach infinity and the Effective Cell Service Rate (Loaded) drops to zero.


All Servers Array This feature is not a true array, since it is sensitive to the location of your mouse cursor. It is a more basic version of the Pixel Analyser tool (for more information on the Pixel Analyser, see the ASSET3g User Reference Guide).

It displays information about which cells are "covering" each pixel. A set of lines is drawn between all possible serving cells to the simulation pixel where the mouse cursor is located. For pixels with more than one covering cell, the line thickness increases proportionally.

This array enables you to identify distant servers so that you can optimise your network design by lowering, moving or reducing the pilot power of problematic sites.

The covering cells are shown in order of either:

Best Servers by Pilot Strength (according to the threshold set in the Array Settings dialog box). This will work even if you have not yet run any snapshots because it relates to the power in the cell and path loss, not to any simulation results.

Best Servers by Ec/Io. This requires snapshots to have been run because it relates to attempted connections. Lines are only drawn if a terminal has been served on that pixel.

This picture shows an example of the All Servers array:

All Servers array


Arrays (5.0 Simulator) There are three groups of arrays that can be generated using the 5.0 Simulator:

3g Service Arrays 3g Carrier Arrays GSM Arrays

3g Service Arrays (5.0 Simulator) The 3g Service arrays generated using the 5.0 Simulator wizard are listed within the Simulator heading in the Map View Data Types.

Example of the Service Arrays under the Simulator heading in the Data Types list

Best Server Array

This array enables you to view the geographical areas where each cell is the Best Serving Cell for the selected service.

The colours are assigned automatically. However, by double-clicking the array in the list of Data Types, you can change the Coverage Probability threshold so that only those pixels with a coverage probability above the threshold will show a best server. You can also change the transparency.

Coverage Probability Array

This array displays the probability of service at a pixel defined as:

As with all the arrays, you can change the display properties by double-clicking the array in the list of Data Types. For this array, you can set up colours and percentage categories to display different coverage probabilities.


Coverage Probability for Nth Best Server Array

This array displays the probability of a service connection with a specific covering cell. In other words, the probability that a user accessing a specific service on a terminal manages a successful connection to the cell. The array displays the probability that the service connects to its Nth best server.

When you double-click the item in the list of display types, you can:

Enter the number of the server array you want displayed on the map. This number must be less than or equal to the number of covering cells that you have specified during the set-up of the 5.0 Simulator wizard.

Set up colours and percentage categories to display different coverage probabilities.

Example of Coverage Probability for Nth Best Server

In this example, one of the pixels on the Map View might be served by various surrounding cells as follows:

Terminal Cell

1 32A

2 32A

3 34A

4 36B

5 35B

6 32A

7 32A

8 35B

9 36B

10 35B

This would mean that at that pixel, coverage probability for the 1st best server would be 4/10, or 40% for cell 32A. Coverage probability for the 2nd best server would be 3/10 or 30%, for cell 35B. Coverage probability for the 3rd best server would be 2/10 or 20%, for cell 36B. Coverage probability for the 4th best server would be 1/10 or 10%, for cell 34A. There is no 5th best server in this case.

Downlink Achieved Eb/No or Eb/Io Array

This array displays the achieved Eb/No (UMTS) or Eb/Io (CDMA2000 or HDR) of a successfully served terminal on the downlink for the selected service.

The following calculation shows how the array is defined using Eb/No for a UMTS network:


Note : To define the downlink achieved Eb/Io, use the same equation substituting Eb/No for Eb/Io.

As with all the arrays, you can change the display properties by double-clicking the item in the list of Data Types.

Downlink Frame Error Rate Array

This array displays the mean achieved FER on the downlink for the selected service.

As with all the arrays, you can change the display properties by double-clicking the item in the list of Data Types.

Downlink Packet Delay Array

This array assesses the total packet transmission time of each sector, places it into one of the following categories, and colours the map accordingly:

Conversational, for example voice traffic, delay < 250ms Interactive, for example interactive games or www browsing, 250ms delay < 4s Streaming, for example ftp, audio & video traffic, 4s delay < 10s Background, for example e-mail arrival notification, best effort traffic, 10s delay

Mean Downlink Bitrate Array

This array displays the mean downlink bitrate for terminals at each pixel for the selected services.

Mean Number of Soft Handover or Handoff Cells Array

This array displays the mean number of soft handover/handoff cells for terminals at each pixel for the selected service.

Mean Number of Softer Handover or Handoff Cells Array

This array displays the mean number of softer handover/handoff cells for terminals at each pixel for the selected service.

Mean Size of Active Set Array

This array displays the mean size of the active set, which comprises serving cells as well as all soft and softer handover cells. This size is limited by what you have specified in the Active Set Size box on the Cell Params tab, when a cell is selected in the Site Database.

Mean Uplink Bitrate Array

This array displays the mean uplink bitrate for terminals at each pixel for the selected services.


Most Probable Handover/ Handoff Type Array

This array displays for each pixel the most probable handover/handoff type, but only on the basis that handover/handoff actually occurred at that pixel. This allows you to check whether you are using too much radio resources. If the array shows areas with no handover/handoff, this indicates instances of primary connection only.

You can change the colours for this array in the display properties dialog box. Also in this dialog box, you can set the thresholds for when to show soft handover/handoff, softer handover/handoff, or both types of handover/handoff, depending on the probability.

No Server Array

This array (GSM only) displays the areas where there is not enough power for calls to be transmitted.

Path Balance Array

This array displays whether the Eb/No on the uplink and downlink are above the required thresholds at each pixel for the selected service. The array indicates the areas where:

both uplink and downlink have failed uplink only has failed downlink only has failed both uplink and downlink have succeeded When you specify a desired coverage probability for the uplink and downlink, the array displays the regions in which the desired coverage probability is attained.

The downlink coverage probability is defined as:

The uplink coverage probability is defined as:

You can change the colours for this array in the display properties dialog box. Also in this dialog box, set thresholds for uplink and downlink coverage probability. Anything under the thresholds you set will be considered to be a failed link.


Probability of Downlink Capacity Failure Array

This array displays the probability of failure due to the serving base station being unable to meet the downlink required Eb/No (UMTS) or Eb/Io (CDMA2000 or HDR). This is because the base station has insufficient power and tends to occur when a cell is heavily loaded.

Probability of Downlink Channel Limit Failure Array

This array displays the probability of failure due to an insufficient number of downlink channels being available at the serving sector-carrier (including channels on the site and sector pools). This is displayed as a percentage.

Probability of Downlink Channels No Primary Failure Array

This array displays the probability of failure due to the downlink primary channel limit on the serving sector-carrier being exceeded. This is displayed as a percentage.

Probability of Downlink Eb/No Range Failure Array

This array displays the probability of failure due to the serving base station not being able to meet the downlink required Eb/No (UMTS) or Eb/Io (CDMA2000 or HDR), caused by the transmit power exceeding the allowed power for a downlink. This tends to occur when a mobile is too far from a site.

Probability of Downlink Resource Limit Failure Array(s)

This array displays the probability of failure due to the serving cell resource limit being exceeded. This is displayed as the average percentage blocking for this service, based on the maximum number of resources that you have set up on the Resource tab in the Site Database.

Probability of Downlink Resource No Primary Failure Array(s)

This array displays the probability of failure due to insufficient primary resources available on the downlink. This is based on the maximum number of resources that you have set up on the Resource tab in the Site Database.

Probability of Low Control C/I Failure Array

This array (GSM only) displays the probability of failure due to interference to the 'control' (BCCH) carrier.


Probability of Low Ec/Io Failure Array

This array displays the probability of failure due to insufficient Ec/Io on the downlink, that is:

This array will be displayed as the average percentage blocking per service.

Probability of Low Pilot SIR Failure Array

This array displays the probability of failure due to insufficient pilot SIR on the downlink, that is:


Probability of Low Traffic C/I Failure Array

This array (GSM only) displays the probability of failure due to interference to the 'traffic' (TCH) carrier.

Probability of No Carrier Failure Array

This array displays the probability of failure due to the service on the terminal being unable to receive the required carrier from any of the covering cells, that is:

Probability of No Cell Timeslot (TS) Available Array

This array (GSM only) displays the probability of no cell timeslots being available to transmit.

Probability of No Terminal Timeslots (TS) Available Array

This array (GSM only) displays the probability of no terminal timeslots being available to transmit.


Probability of Noise Rise Failure Array

This array takes account of the cell noise rise limits that you have set for the cells and displays the probability of failure due to a cell noise rise limit being exceeded on the uplink.

Noise Rise in dB is set per cell on the Cell Params tab in the Site Database.


Note : When a connection is attempted, a calculation is made to assert that the noise rise limit is not broken for the primary cell AND any neighbour cells. If the noise rise limit is broken, this is logged as a noise rise failure on the primary cell, even if the noise rise limit was broken on another cell.

The array is defined as:

Probability of Soft Handover/Handoff Array

This array displays the probability of one or more soft handover/handoff connections taking place at each pixel for the selected service.

This is defined as:

A strictly soft handover means that if there are multiple handover cells for a service on a terminal, then all of the handovers are soft. If any of the handovers are softer, the service is deemed to be in softer handover.

Probability of Softer Handover/Handoff Array

This array displays the probability of one or more softer handover/handoff connections taking place for the selected service.

This is defined as:


Probability of Uplink Eb/No Failure for a UMTS Network Array

This array displays the probability of failure due to the user equipment being unable to meet the uplink required Eb/No for a UMTS network. The array is defined as:

This array is displayed as the average percentage blocking for this service.

Probability of Uplink Resource Limit Failure Array(s)

This array displays the probability of failure on the uplink due to the serving cell resource limit being exceeded. This is displayed as the average percentage blocking for this service. It is based on the maximum number of resources that you have set up on the Resource tab in the Site Database.

Probability of Uplink Resource No Primary Failure Array(s)

This array displays the probability of failure due to insufficient primary resources available on the uplink. This is based on the maximum number of resources that you have set up on the Resource tab in the Site Database.

Reason for Failure Array

This array analyses the results of all the failure arrays and displays the most probable reason for failure (that is, the most dominant one) for each pixel. An extra condition -"excessive path loss" - is also considered. If the path loss is greater than 200 dB, this is considered too excessive to ever make a connection.

This array enables you to easily identify the primary reason for failures in the different geographic areas.

In the display properties dialog box, you can choose to use the default colours for the automatically assigned categories or to change the colours. You can also set up the coverage probability threshold to ensure that failures are displayed only if the coverage probability is below the value you enter.

Uplink Eb/Nt Failure Array

This array displays the probability of failure due to the user equipment being unable to meet the uplink required Eb/Nt for a CDMA2000 or HDR network.

This array is displayed as the average percentage blocking for this service.

Uplink Required TX Power Array

This array displays the mean uplink required Transmit Power at each pixel for the selected service.


3g Carrier Arrays (5.0 Simulator) The 3g Carrier arrays generated using the 5.0 Simulator wizard are listed within the Simulator heading in the Map View Data Types.

Example of the Carrier Arrays under the Simulator heading in the Data Types list

All Servers Array

This feature is not a true array, since it is sensitive to the location of your mouse cursor. It is a more basic version of the Pixel Analyser tool (for more information on the Pixel Analyser, see the ASSET3g User Reference Guide).


This array enables you to identify distant servers so that you can optimise your network design by lowering, moving or reducing the pilot power of problematic sites.


Best Servers by Pilot Strength (according to the threshold set in the Array Settings dialog box). This will work even if you have not yet run any snapshots because it relates to the power in the cell and path loss, not to any simulation results.

Best Servers by Ec/Io. This requires snapshots to have been run because it relates to attempted connections. Lines are only drawn if a terminal has been served on that pixel.


This picture shows an example of the All Servers array:

All Servers array

Best Server by Pilot Array

This displays the best serving cell by pilot power for the selected carrier at each pixel. This array is affected by the pilot strength threshold which you set in the Array Settings dialog box.

Cell/Sector Uplink Load Array

This array displays at each pixel the uplink load for the best serving cell (by pilot power).

Note : For TD-SCDMA networks this is for the time slots given.

Cell uplink load is defined as:

Noise rise at the cell is defined as:


Downlink Packet Delay Array

This array assesses the total packet transmission time of each sector, places it into one of the following categories, and colours the map accordingly:

Conversational, for example voice traffic, delay < 250ms Interactive, for example interactive games or www browsing, 250ms delay < 4s Streaming, for example ftp, audio & video traffic, 4s delay < 10s Background, for example e-mail arrival notification, best effort traffic, 10s delay

Ec/Io for Nth Best Server Array

This array displays the strongest Ec/Io, second strongest Ec/Io, third strongest Ec/Io and so on up to the number of covering cells chosen in the 5.0 Simulator wizard.

This array is useful in helping you determine the causes of pilot interference. For example, if you can see that a particular cell is the second strongest pilot in a lot of areas that are far from its own service area, then you will know that that particular cell will be a likely pilot polluter (that is, interfering or degrading the pilot signals of surrounding cells).

In the display properties dialog box, you can specify which of the Nth best server arrays you want displayed.

Mean Received Power Array

This array displays the total mean received RF power over a carrier's bandwidth, found by adding the received pilot powers, common channel powers, traffic channel powers and background noise at any pixel. The value at each pixel is obtained by averaging the total received powers of the terminals attempted at a pixel.

Mean Received PSD (Io) Array

This array displays the total received power on the downlink divided by the bandwidth for the selected service, at each pixel.

Note : For TD-SCDMA networks, this is for the timeslots given.

Nth Lowest Downlink Loss Array

This array displays the lowest downlink loss in dB for the selected carrier, then the next lowest loss, and so on until N, where N is less than or equal to the number of serving cells you have specified in the 5.0 Simulator wizard.


Number of Pilot Polluters Array

Any cell that provides an Ec/Io level higher than the number of Pilot Pollution threshold, but is not in the terminal's active set, is considered to be a pilot polluter for the terminal. This array is provided as an output by the 5.0 Simulator and shows the average number of pilot polluters on each carrier.

Pilot Coverage Array

The Pilot Coverage array displays the pilot strength in dBm for the selected carrier and is useful when determining pilot interference. This array shows the same information as the Pilot Strength array, but the powers can be grouped into categories of pilot strength. For example, you may want to categorise received powers of -60 to -50 dBm to be Rural Outdoor.

Pilot Ec/Io Array

This array displays the achieved pilot Ec/Io for each pixel and is in effect, the same as Ec/Io for the best server.

Note : The Ec/Io value includes intra-cell interference, whereas the SIR value excludes intra-cell interference.

Pilot SIR Array

This array displays the achieved pilot SIR for each pixel.

Note : The SIR value excludes intra-cell interference, whereas the Ec/Io value includes intra-cell interference.

Pilot Strength Array

This array displays the pilot strength in dBm for the selected carrier and is useful when determining pilot interference.

Pilot Strength for Nth Best Server Array

The Pilot Strength for Nth Best Server array displays the strongest pilot power in dBm for the selected carrier, then the next strongest and so on until N, where N is less than or equal to the number of serving cells you have specified in the 5.0 Simulator wizard. Use this array to determine the causes of pilot interference.

In the display properties dialog box, you can specify which of the Nth best server arrays you want displayed.


GSM Arrays (5.0 Simulator) The GSM arrays generated using the 5.0 Simulator wizard are listed within the Simulator heading in the Map View Data Types.

Example of the GSM Arrays under the Simulator heading in the Data Types list

Best Server Signal Array (GSM)

This array displays the signal strength of the best serving cell at each pixel on the Map View. This decision is based on parameters specified in the Site Database window and in the Array Settings dialog box.

As with all the arrays, you can change the display settings in the Map View by double-clicking the array in the list of Data types.

All Servers (GSM) Array

This array is sensitive to the location of your mouse cursor.


This array enables you to identify distant servers so that you can optimise your network design by lowering, moving or reducing the power of problematic sites.


Best Signal Strength (according to the threshold set in the Array Settings dialog box). This will work even if you have not yet run any snapshots because it relates to the power in the cell and path loss, not to any simulation results.

Best Server by C/I. This requires snapshots to have been run because it relates to attempted connections. Lines are only drawn if a terminal has been served on that pixel.


Average Connection Arrays (Traffic and Control)

There are two Average Connection arrays, one for Traffic, the other for Control. The 'Traffic' calculation includes all carrier layers while 'Control' only includes control carrier layers. If a cell layer has no control carrier layer allocated then the value will be taken from the best alternative cell layer on the same site.

For each pixel on a selected cell layer, the serving sub-cell is determined, and for each hopping carrier group the average carrier to interference (C/I) is calculated from the corresponding pixel in the per carrier interference array by converting total C/I to BER and calculating the mean. The mean BER is converted back to dB and the average value for all hopping carrier groups is presented.

For information on the algorithm used, see Average Connection Array Calculation Method on page 42.

Note : This interference array type was designed for networks using frequency hopping, although it also works for non-hopping networks. In a non-hopping network, the carrier group can be considered to contain just a single carrier in the above description.

Note : This array is not available for AMPS/TDMA networks.

Lowest Downlink Loss (GSM) Array

In this array, at each pixel, the downlink losses of covering cells that use the selected carrier are examined, and the lowest of these losses is displayed .

This loss includes all relevant gains and losses in the downlink except those associated with the terminal type. For example, antenna gain, feeder loss, MHA insertion loss or Tx combiner loss are included, but terminal antenna gain and body loss are excluded.

Nth Best Server (GSM) Array

For each pixel on the selected cell layer, ASSET3g determines which serving cell layer will be the most likely server of a mobile in that pixel, plus the next most likely until N. This decision is based on parameters specified in the Site Database window and in the Array Settings dialog box.

The difference between Best Server arrays and Nth Best Server arrays is that when creating an Nth Best Server Array, the number of layers is the same as the number of GSM covering cells. You then choose which layer you wish to view.

Service Area (GSM) Array

Service areas enable you to view the information from the Best Server Signal array in terms of the geographical areas where each cell is the Best Serving Cell. It uses the same information as the Best Server Signal array, but displays it in a different way.


2g and 2.5g (Non-Sim) Arrays There are a number of different Coverage/Interference arrays that can be generated for 2g and 2.5g, using the Array Creation wizard.

Coverage and Interference Arrays (2g + 2.5g) (Non-Sim) The 2g and 2.5g arrays, generated using the Array Creation wizard, are listed within the Coverage heading in the Map View Data Types.

Example of the 2g/2.5g Arrays under the Coverage heading in the Data Types list

Best Server Array

This array displays the signal strength of the best serving cell at each pixel on the Map View. This decision is based on parameters specified in the Site Database window and in the Array Settings dialog box.

As with all the arrays, you can change the display settings by double-clicking the array in the list of Data Types. For details of how to modify or set up schemas for this array, see the ASSET3g User Reference Guide.


This picture shows an example of the Best Server array:

Best Server array

Best Server (GPRS) Array

For each pixel, ASSET3g determines which serving cell layer will be the most likely server of a mobile in that pixel. This decision is based on parameters specified in the Site Database window and in the Array Settings dialog box.

The Best Server (GPRS) array is identical to the Best Server array, except that it will exclude non-GPRS sub-cells from the calculation.

Best Server EDGE Arrays

Best Server (EDGE GMSK) Array

A subset of the GPRS Best Server array, which only includes EGPRS cells. The EDGE GMSK array displays the pathloss from the server to that pixel of a signal using Gaussian Minimum Shift Keying (GMSK) modulation.

Best Server (EDGE 8-PSK) Array

Covers the same subcells as the EDGE GSK array, but applies the APD to the subcells, making the service area of each subcell generally smaller. If the APD is set to 0, then both Best Server EDGE arrays will be identical. The EDGE 8-PSK array displays the pathloss from the server to that pixel of a signal using 8-PSK modulation.


LMU Arrays

Location Measurement Units (LMUs) are used to locate a subscriber and/or their mobile equipment. LMU arrays can indicate geographically where a mobile station can be measured by more than three separately located base stations (through position triangulation).

The mobile can only receive effective signals where:

1 The received signal strength at the mobile station is above the signal strength threshold that you have set in the Array Settings dialog box.

2 The total C/I due to inteference from the other cells at the mobile station is above the C/I threshold that you have set.

Therefore, you can create two separate arrays:

MS Measured Cells MS Measured Cells (C/I)

MS Measured Cells Array

For the MS Measured Cells array, ASSET3g creates an Nth Best Server array for the selected region based on the selected cells and settings specified in the Array Settings dialog box (including the received signal strength threshold and the timing advance).

Note : Only the count of Best Servers are stored, and not the sub-cells.

MS Measured Cells (C/I) Array

For the MS Measured Cells (C/I) array, ASSET3g creates an Nth Best Server array for the selected region, based on a received signal strength threshold of 160dBm, the selected cells and the rest of the settings specified in the Array Settings dialog box.

To calculate the C/I for each potential server, ASSET3g performs the following calculation for each pixel in the Nth best server array:

1 ASSET3g calculates the worst C/I and the total C/I.

2 ASSET3g then calculates and stores the worst interfering sub-cell, based on a consideration of every other serving cell entry in the Nth Best Server array for that pixel.

The calculations in steps 1 and 2 are based on:

Each serving cell entry in the Nth Best Server array, where the signal strength is equal to or greater than the received signal strength threshold in the Array Settings dialog box

Each carrier of the serving cell, where the carrier is on a control layer 3 ASSET3g then post-processes the array to calculate the average C/I for each pixel,

and each serving cell entry in the Nth Best Server array.

Tip : In the Map Information Window (accessed from the View menu in the Map View), if you hover over a cell, the number of cells that could be measured by the LMU is displayed for each array that has been calculated.


GPRS Data Rate Array

The GPRS Data Rate array shows the maximum data rate (in kbits per second) that you can achieve at a particular pixel using GPRS technology.

Use the GPRS Data Rate array to see where in a area you will get what performance. This type of array requires a Best Server (GPRS) array, which is generated automatically if one does not already exist.

The GPRS Data Rate array determines coverage for cells that support GPRS and includes the effect of Frequency Hopping and DTX. The array calculates a pixel's average C/I value, ignoring the signal (C) from non-GPRS cells but considering interference for all cells, both GPRS and non-GPRS.

When the average C/I value for each pixel has been determined, the array converts it from a signal to noise ratio to a data rate per timeslot by referring to the Channel Coding Scheme. For details, see the ASSET3g User Reference Guide. Only Channel Coding Schemes supported by the best serving subcell are included. The data rate is stored in the array.

You can specify the cell layer/carrier layer combinations to be considered when calculating the GPRS data rate array by selecting the appropriate combinations in the Interference tab of the Array Settings dialog box.

As with other arrays, you can double-click the item from the Data Types list on the Map View to change the displayed colours and categories for the array.

GPRS Average Data Rate per Timeslot Array

The GPRS Average Data Rate per Timeslot display uses the serving cell information from the Best Server (GPRS) array.

The Average Data Rate per Timeslot array uses the distribution of traffic (Terminal Types/km) and the data demands of each type. It then calculates an average data rate per timeslot for the cell. This is calculated and stored when the GPRS Data Rate array is produced.

It uses the GPRS Data Rate array to give a data rate per timeslot (kb/s). This value is then multiplied by the number of terminals of that type present to get the demand for that pixel for that terminal type.

The results for each terminal type for all the pixels within a sub-cell are then divided by the number of terminals of that type with the sub-cell. The result for each terminal type present is then averaged to generate the average data rate per timeslot, which is then stored on the sub-cell.

For more details on the calculations, see Grade of Service and Data Rate on page 51.

Note : If the traffic array and the GPRS Data Rate array are of different resolutions, the GPRS Data Rate array is interpolated to get the corresponding kb/s for each traffic array pixel.


To display this on the map, ensure Average Data Rate per Timeslot (GPRS) is selected in the list of data types to display. The area covered by each GPRS sub-cell is displayed on the map in the colour corresponding to its average data rate per timeslot.

When displayed on the map, the array has different colours representing the different service levels in a kb/s/timeslot. For example:

High (Multimedia) >12kb/s (Red) Medium (Web access) 7-12kb/s (Green) Low (e-mail) 2-7kb/s (Blue)


EGPRS Data Rate Array

Use the EGPRS Data Rate array to see where in a area you will get what performance. This type of array requires an EGPRS best server array, which is generated automatically if one does not already exist.

The EGPRS Data Rate array is based on the following data:

EGPRS-enabled cells EGPRS modulation/coding schemes Frequency hopping LA families supported by the subcells The power drop (APD) observed with 8-PSK modulation The EGPRS Data Rate array determines coverage for cells that support EGPRS and includes the effect of Frequency Hopping and DTX. The array calculates a pixel's average C/I value, ignoring the signal (C) from non-EGPRS cells but considering interference for all cells, both EGPRS and non-EGPRS.

Note : If you are taking traffic into account for interference and the 8-PSK traffic mix of any subcell is greater than zero, ASSET3g assumes that the percentage of the traffic is 8-PSK (which uses less power because of the APD and causes less interference).

When the average C/I value for each pixel has been determined, the array converts it from a signal to noise ratio to a data rate per timeslot by referring to the Coding Scheme. For details, see the ASSET3g User Reference Guide.

It works out two of these data rates, one for the best GMSK available, and one for the best 8-PSK available, and then chooses the one that gives the best overall data rate to store.

You can specify the cell layer/carrier layer combinations to be considered when calculating the EGPRS data rate array by selecting the appropriate combinations in the Interference tab of the Array Settings dialog box.



EGPRS Average Data Rate per Timeslot Array

The EGPRS Average Data Rate per Timeslot display uses the serving cell information from the Best Server (EGPRS) array.

The Average Data Rate per Timeslot array uses the distribution of traffic (Terminal Types/km) and the data demands of each type. It then calculates an average data rate per timeslot for the cell. This is calculated and stored when the EGPRS Data Rate array is produced.

It uses the EGPRS Data Rate array to give a data rate per timeslot (kb/s). This value is then multiplied by the number of terminals of that type present to get the demand for that pixel for that terminal type.

The results for each terminal type for all the pixels within a sub-cell are then divided by the number of terminals of that type with the sub-cell. The result for each terminal type present is then averaged to generate the average data rate per timeslot, which is then stored on the sub-cell.

For more details on the calculations, see Grade of Service and Data Rate on page 51.

Note : If the traffic array and the EGPRS Data Rate array are of different resolutions, the EGPRS Data Rate array is interpolated to get the corresponding kb/s for each traffic array pixel.

To display this on the map, ensure Average Data Rate per Time Slot (EGPRS) is selected in the list of data types to display. The area covered by each EGPRS sub-cell is displayed on the map in the colour corresponding to its average data rate per timeslot.

When displayed on the map, the array has different colours representing the different service levels in a kb/s/timeslot. For example:

High (Multimedia) >12kb/s (Red) Medium (Web access) 7-12kb/s (Green) Low (e-mail) 2-7kb/s (Blue)


GPRS Service Area Data Rate Array

The GPRS Service Area Data Rate array displays the capacity limited GPRS data rate for each serving cell.

The data rates are displayed accordingly to chosen categories over the service area of each server. For example, for a server whose capacity limited data rate is 6kb/s, the service area of this server will be displayed as the appropriate category. The default category in this case would be e-mail as according to the default scheme, the data rate range for e-mail is 1-28 kb/s. The service area for this cell would therefore be coloured in the colour for the category e-mail.



EGPRS Service Area Data Rates Array

The EGPRS Service Area Data Rate array displays the capacity limited EGPRS data rate for each serving cell.

The data rates are displayed accordingly to chosen categories over the service area of each server. For example, for a server whose capacity limited data rate is 6kb/s, the service area of this server will be displayed as the appropriate category. The default category in this case would be e-mail as according to the default scheme, the data rate range for e-mail is 1-28 kb/s. The service area for this cell would therefore be coloured in the colour for the category e-mail.


Interference Arrays

Note : When creating one of the Interference arrays, ASSET3g requires a Best Server array in memory. If this is not the case, a Best Server array will be automatically created. However, if you later create subsequent Interference arrays after making changes to the network, ASSET3g does not automatically create a fresh Best Server array.

Therefore, in cases where you suspect the Best Server array in memory has become out of date for any reason, you should explicitly create both the Best Server array and the required Interference array when running the Array Creation wizard. For example:

Example of creating Best Server array and required Interference array in the Coverage/Interference wizard


Worst Connection Array

For each pixel, the serving sub-cell is determined and for each hopping carrier group the average carrier to interference (C/I) is calculated from the corresponding pixel in the per carrier interference array by converting total C/I to BER and calculating the mean. The mean Bit Error Rate is converted back to dB and the hopping carrier group with the lowest resultant C/I is presented, that is, it corresponds to the worst of the mean connection C/I values.

For information on the algorithm used, see Worst Connection Array Calculation Method on page 41.

Important : Worst connection arrays require a Best Server array, which is generated automatically if one does not already exist in memory. If a best server array already exists but its contents are out of date, you will need to recreate it by explicitly selecting to create both the Best Server and Worst Connection arrays in the Array Creation wizard.



Average Connection Array

For each pixel, the serving sub-cell is determined, and for each hopping carrier group the average carrier to interference (C/I) is calculated from the corresponding pixel in the per carrier interference array by converting total C/I to BER and calculating the mean. The mean BER is converted back to dB and the average value for all hopping carrier groups is presented.

For information on the algorithm used, see Average Connection Array Calculation Method on page 42.

Important : Average Connection arrays require a Best Server array, which is generated automatically if one does not already exist in memory. If a best server array already exists but its contents are out of date, you will need to recreate it by explicitly selecting to create both the Best Server and Average Connection arrays in the Array Creation wizard.




Worst Interferer Array

For each pixel, the carrier with the worst carrier to interference (C/I) is determined from the corresponding total C/I value in per carrier interference array. The result is the worst C/I and the sub-cell from which the interference originates.

For information on the algorithm used, see Worst Interferer Array Calculation Method on page 43.

Important : Worst Interferer arrays require a Best Server array, which is generated automatically if one does not already exist in memory. If a best server array already exists but its contents are out of date, you will need to recreate it by explicitly selecting to create both the Best Server and Worst Interferer arrays in the Array Creation wizard.

Note : This array does not consider frequency hopping, and so can be considered to be an interference calculation for a non-hopping version of the frequency plan.

Total Interference Array

For each pixel, the total carrier to interference (C/I) is calculated by summing the total C/I per carrier. This array is applicable to both fully-loaded frequency hopping and non-hopping networks. The calculated C/I is NOT merely as experienced by any individual subscriber, but rather it represents the total of the interference experienced by ALL subscribers at each pixel.

For information on the algorithm used, see Total Interference Array Calculation Method on page 43.

Important : Total Interference arrays require a Best Server array, which is generated automatically if one does not already exist in memory. If a best server array already exists but its contents are out of date, you will need to recreate it by explicitly selecting to create both the Best Server and Total Interference arrays in the Array Creation wizard.

About Per Carrier Interference

For all the interference calculations, ASSET3g generates an intermediate internal array called a per carrier interference array. For each pixel in the array the serving sub-cell is determined and for each carrier of the serving sub-cell the worst carrier to interference (C/I) (lowest numerical value) and the total C/I is calculated taking into consideration all co and adjacent carriers from all interfering sub-cells.

The total C/I is determined by summing the interfering signals in watts then later converting back to dB. The result is an array such that for each pixel, a list is obtained of serving carriers plus the worst and total C/I for each carrier.

You cannot currently visualise this intermediate array, which no longer exists when all the other selected arrays have been created.


Total Received Power Array

This array show the sum of energy absorbed at any one point from all base stations on a per pixel basis. For each pixel, received power is calculated in dBm from each of the sub-cells. This value is converted to watts, summed and converted back to dBm.

When you have determined the total received power, you can use this information for making safety decisions. You can also generate statistical reports showing this information. Each pixel in the area of map you have selected is processed and a list is created of sub-cells that have prediction files overlapping the area.

Note : Distributed antenna systems are treated as separate power sources.


2g and 2.5g Algorithms

In This Section Interference Table Algorithm Interference and Connection Array Calculations Frequency Hopping Algorithms Non-Frequency Hopping Algorithms Automatic Frequency Planning (ILSA) MAIO Planning Cost Function GPRS and HSCSD Capacity Calculations FCC Calculations Frequency Calculations

Interference Table Algorithm The Interference Table stores the following four values for any pair of sub-cells A and B. These relate to the region where A is the best server.

Field Name Description Co-channel Traffic The amount of traffic served by cell A that would be affected by interference if A

and B were to be assigned the same carrier.

Co-channel Area The area served by cell A that would be affected by interference if A and B were to be assigned the same carrier.

Adjacent Channel Traffic The amount of traffic served by cell A that would be affected by interference if A and B were to be assigned adjacent carriers.

Adjacent Channel Area The area served by cell A that would be affected by interference if A and B were to be assigned adjacent carriers.

The values for area are obtained by averaging the probability of interference over the region where A is the best server. The average is taken over all pixels in the appropriate coverage array.

For traffic, the value to be averaged is the probability of interference x the traffic (in mE) at that pixel. Thus it is necessary to have a traffic raster available to make this calculation.

A P P E N D I X B


The probability of interference at a given pixel is calculated using a standard statistical technique based on a C/I signal threshold value and a standard deviation. The assumption is that a difference in signal level between server and interferer exactly equal to the threshold value would give rise to a 50% chance of co-channel interference. For more information on how these values can be specified, see the ASSET3g User Reference Guide.

By default, a -18dB offset is used for the adjacent channel interference, relative to the co-channel interference. This means that if, for example, the co-channel C/I threshold value is set at 9dB, a signal difference of -9dB between server and adjacent channel interferer would give rise to a 50% chance of adjacent channel interference. The C/A offset can be modified in the Array Settings dialog box.

All signal differences are converted into probabilities of interference. This graph displays the spread of probabilities for both C/I and C/A based on the default Interference Weights. Here, the C/I signal threshold value is 9 dB, using a standard deviation of 7.78dB.

C/I and C/A weights curve

Note : An example of an Interference Table can be found, along with a description of its File Format, in the ENTERPRISE User Reference Guide.

Interference and Connection Array Calculations This table shows the different interference analyses that are possible:

Field Name Description Worst Connection C/Ic Determines the co-channel C/I levels for all of the possible interfering

frequencies that may be used by the MS-BTS connection.

Each pixel presents the worst C/Ic level and frequency.

Worst Connection C/Ia Determines the adjacent channel C/I levels for all of the possible interfering frequencies that may be used by the MS-BTS connection.

Each pixel presents the worst C/Ia level and frequency.

Worst Connection C/(Ic+Ia) Determines the combined co-channel/adjacent channel C/I levels for all of the possible interfering frequencies that may be used by the MS-BTS connection.

Each pixel presents the worst C/I level and frequency.


Field Name Description Average Interference C/Ic Sums the co-channel C/I levels for all possible interfering frequencies and

presents the average C/Ic level.

Average Interference C/Ia Sums the adjacent channel C/I levels for all possible interfering frequencies and presents the average C/Ia level.

Average Interference C/(Ic_Ia) Sums the combined co-channel and adjacent C/I levels for all possible interfering frequencies and presents the average C/(Ic_Ia) level.

Worst Interference C/Ic For non-frequency hopping networks sums all of the co-channel C/I levels for an interfering frequency.

Each pixel presents the total C/I level, server and interfering sub-cells and interfering frequency.

Worst Interference C/Ia For non-frequency hopping networks sums all of the adjacent channel C/I levels for an interfering frequency.

Each pixel presents the total C/I level, server and interfering sub-cells and interfering frequency.

Note : The worst connection and the worst interferer calculations are the same in the case of a non-frequency hopping network.

Worst Connection Array Calculation Method In the Worst Connection Array calculation, the connection refers to the carrier(s) corresponding to a single call:

In the case of hopping frequencies, it corresponds to the entire group of hopping frequencies

In the case of non-hopping frequencies, it corresponds to a single frequency The Worst Connection Array calculates the C/I per connection, summing over all interferers, and then selects the connection with the lowest C/I.

The algorithm for this is as follows:

Where:

For each non-hopping carrier fi in the serving sub-cell, C/I(fi) is calculated.

For the hopping frequency group in the serving sub-cell, a single C/I(FH) is calculated.


Average Connection Array Calculation Method The Average Connection Array calculates the C/I per connection, summing over all interferers, and then calculates the average of those.

The algorithm for this is as follows:

(2)

Where:

is the averaged C/I for the hopping carriers.

is the number of hopping frequencies.

is the number of non-hopping frequencies.

is frequency Diversity Gain.

is the fractional loading, calculated as follows:

, where is the number of hopping TRX.

are the non-hopping frequencies.

For each non-hopping carrier fri in the serving sub-cell, C/I(fri) is calculated.

For the hopping frequency group in the serving sub-cell, a single C/I(FH) is calculated.

Note : The denominator in the equation above can never be zero ( and cannot both be 0 at the same time). This is because ASSET3g does not allow you to set the total number of TRX allocated to a sub-cell to zero, if at least one carrier layer is allocated.


Worst Interferer Array Calculation Method The Worst Interferer Array calculates the C/I per frequency, summing over all interferers, and selects the frequency with the lowest C/I. It also finds the interferer that causes the most interference on that frequency.

Note : This array does not take into account fractional loading.

The most interfered frequency and its corresponding C/I are calculated as follows:

If , then

If , then

Where:

For each (non-hopping) carrier f1 in the serving sub-cell, C/I(f1) is calculated.

The worst interferer is calculated as follows:

Total Interference Array Calculation Method The Total Interference Array calculates the C/I per frequency, summing over all interferers, and then sums the C/I for each frequency at the serving cell.

Note : This array does not take into account fractional loading.

The total interference is calculated as follows:

Where:

For each (non-hopping) carrier fi in the serving sub-cell, C/I(fi) is calculated.


Table of Default C/I BER Conversion Values This table shows the Default C/I BER Conversion Values in ASSET3g:

C/I (dB) Bit Error Rate -10 0.5000000000

-9 0.4880000000

-8 0.4650000000

-7 0.4300000000

-6 0.3880000000

-5 0.3500000000

-4 0.3200000000

-3 0.3000000000

-2 0.2700000000

-1 0.2500000000

0 0.2200000000

1 0.2000000000

2 0.1700000000

3 0.1500000000

4 0.1200000000

5 0.1000000000

6 0.0900000000

7 0.0780000000

8 0.0660000000

9 0.0550000000

10 0.0450000000

11 0.0370000000

12 0.0300000000

13 0.0260000000

14 0.0200000000

15 0.0150000000

16 0.0120000000

17 0.0080000000

18 0.0060000000

19 0.0040000000

20 0.0020000000

21 0.0007000000

22 0.0001000000

23 0.0000070000

24 0.0000004000

25 0.0000000100


C/I (dB) Bit Error Rate 26 0.0000000001

27-45 0.0000000000

Frequency Hopping Algorithms The algorithms used for frequency hopping cells are as follows:

1 is used if , is used if , 0 is used otherwise

Where: C/I(i) = C/I ratio for frequency i

SSC(i) = Signal strength from frequency i for serving cell

i,j = A particular frequency

ASSET3g Technical Reference Guide

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