80 w0324 1_a

CDMA2000 1X Network Characterization Seminar

CDMA University1 2 63 4 5 97 8 10



Student Guide

80-W0324-1 Rev A

Material Use RestrictionsThese written materials are to be used only in conjunction with the associated instructor-led class. They are not intended to be used solely as reference material.

No part of these written materials may be used or reproduced in any manner whatsoever without the written permission of QUALCOMM Incorporated.

Copyright © 2005 QUALCOMM Incorporated. All rights reserved.

QUALCOMM Incorporated5775 Morehouse DriveSan Diego, CA 92121U.S.A.

Export of this technology may be controlled by the United States Government. Diversion contrary to U.S. law prohibited.

QUALCOMM is a registered trademark and registered service mark of QUALCOMM Incorporated.

cdma2000® is a registered certification mark of the Telecommunications Industry Association. Used under license. All other trademarks and registered trademarks are the property of their respective owners.

CDMA2000 1X Network Characterization Seminar 80-W0324-1 Rev A

© 2005 QUALCOMM Incorporated iii

Table of Contents Section 1: Course Overview and Software Installation...................... 1-1 What Will You Learn in the Seminar? .................................................... 1-2 Topics (1): Sections in This Course......................................................... 1-3 Contents of the Course CD ...................................................................... 1-4 Installing TatukGIS Viewer .................................................................... 1-5 Creating the TatukGIS File Association .................................................. 1-6 Testing Interactive Data Content ............................................................ 1-9 Section 2: Network Characterization Process Overview ................... 2-1 Topics (2): Network Characterization Process Overview ...................... 2-2 Section Learning Objectives .................................................................... 2-3 The Network Characterization Process.................................................... 2-4 Definition of Network Characterization .................................................. 2-5 Key Performance Indicators Basic KPIs.................................................................................... 2-6 Capacity KPIs .............................................................................. 2-7 CDMA/Secondary KPIs............................................................... 2-8 Dependencies ............................................................................... 2-9 When is Network Characterization Performed? .................................... 2-10 Initial Network Characterization Steps.................................................. 2-11 Initial and Periodic Steps ....................................................................... 2-12 Optimizing and Maintaining QoS ......................................................... 2-13 Network Characterization Process Overview – What Did We Learn?.. 2-14 Section 3: The Network Planning Stage.............................................. 3-1 Topics (3): The Network Planning Stage............................................... 3-2 Section Learning Objectives .................................................................... 3-3 How Network Planning and Network Characterization are Related ....... 3-4 Network Planning Issues.......................................................................... 3-7 The Network Planning Stage – What Did We Learn? ............................. 3-8 Section 4: Reviewing Network Status .................................................. 4-1 Topics (4): Reviewing Network Status................................................... 4-2 Section Learning Objectives .................................................................... 4-3 Why Review Network Status? ................................................................. 4-4 Network Status Issues that Invalidate Network Characterization............ 4-5 Network Status Tests ............................................................................... 4-6 Reviewing Network Status – What Did We Learn? ................................ 4-8


© 2005 QUALCOMM Incorporated iv

Section 5: Reviewing CDMA2000 Parameters................................... 5-1 Topics (5): Reviewing CDMA2000 Parameters..................................... 5-2 Section Learning Objectives .................................................................... 5-3 What are CDMA Parameters? ................................................................. 5-4 Examples of Problem Parameters ............................................................ 5-5 How to Review Parameters...................................................................... 5-6 Setup for Parameter Extraction/Verification .......................................... 5-7 Reviewing CDMA2000 Parameters – What Did We Learn? .................. 5-8 Section 6: Collecting Performance Data .............................................. 6-1 Topics (6): Collecting Performance Data ............................................... 6-2 Section Learning Objectives .................................................................... 6-3 Collecting Performance Data – BTS/BSC/MSC Logging....................... 6-4 BTS/BSC/MSC Logging ......................................................................... 6-5 Supporting Utilities...................................................................... 6-7 Data Example Set......................................................................... 6-8 Configuration ............................................................................... 6-9 GUI Viewer................................................................................ 6-10 Call Detail Records .................................................................... 6-11 BTS Rx Power ........................................................................... 6-12 RoT Noise and Rx Loading ....................................................... 6-14 Reverse Link Power Control ..................................................... 6-15 Access & Reverse FCH Search Window Size Logging ............ 6-17 BTS/BSC Logging for Neighbor List Management ................. 6-20 Collecting Performance Data – Mobile Logging................................... 6-24 Commercially Available Logging Tools ................................... 6-25 CAIT .............................................................................. 6-27 Spirent ........................................................................... 6-29 Forward Link Scanning.............................................................. 6-30 Role in Network Optimization....................................... 6-31 Required Features .......................................................... 6-32 Basic Scanner Types ...................................................... 6-33 Overriding OTA Parameters .......................................... 6-34 Mobile Logging Tests ............................................................................ 6-35 Receive Power ........................................................................... 6-36 Transmit Power.......................................................................... 6-37 FER ........................................................................................ 6-38 Forward/Reverse Power Control Loop ...................................... 6-39 Access Statistics......................................................................... 6-40 Call Success/Mobile Originated ................................................ 6-41 Call Success/Mobile Terminated ............................................... 6-42 Dropped Call Rate...................................................................... 6-43 Automating Call Activity........................................................... 6-44 Test Units vs. Tests Matrix ........................................................ 6-45 Collecting Performance Data – What Did We Learn?........................... 6-46


© 2005 QUALCOMM Incorporated v

Section 7: Post-Processing..................................................................... 7-1 Topics (7): Post-Processing ..................................................................... 7-2 Section Learning Objectives .................................................................... 7-3 What Does Post-Processing Do? ............................................................. 7-4 Post-Processing Output............................................................................ 7-5 Post-Processing Utilities .......................................................................... 7-7 Features of Post-Processing Software...................................................... 7-8 Actix IQ Analyzer.................................................................................. 7-11 Post-Processing – What Did We Learn?................................................ 7-12 Section 8: KPI Extraction ..................................................................... 8-1 Topics (8): KPI Extraction....................................................................... 8-2 Section Learning Objectives .................................................................... 8-3 Access Attempts Target Values .............................................................................. 8-4 KPI Extraction Procedure ............................................................ 8-5 Active Set Size Target Values and KPI Extraction Procedure.............................. 8-6 Plot Example................................................................................ 8-7 Histogram Example ..................................................................... 8-8 Active Set Pilot Strength Target Values ............................................................................ 8-10 KPI Extraction Procedure .......................................................... 8-11 Plot Example.............................................................................. 8-12 Histogram Example ................................................................... 8-13 Sample Data Analysis ................................................................ 8-14 Search Window Size Determination Target Values ............................................................................ 8-15 KPI Extraction Procedure .......................................................... 8-16 Plot Example.............................................................................. 8-18 Mobile Receive Power Test Target Values ............................................................................. 8-21 Building Penetration Loss.......................................................... 8-22 Example Values ......................................................................... 8-23 KPI Extraction Procedure .......................................................... 8-24 Plot Example.............................................................................. 8-25 Histogram Example ................................................................... 8-26 Sample Data Analysis ................................................................ 8-27 Mobile Forward FER Target Values ............................................................................ 8-28 KPI Extraction Procedure .......................................................... 8-29 Plot Example.............................................................................. 8-30 Histogram Example ................................................................... 8-31 Sample Data Analysis ................................................................ 8-32


© 2005 QUALCOMM Incorporated vi

Mobile Transmit Power Target Values ............................................................................ 8-33 Building Penetration Loss.......................................................... 8-34 Example Values ......................................................................... 8-35 KPI Extraction Procedure .......................................................... 8-36 Plot Example.............................................................................. 8-37 Histogram Example ................................................................... 8-38 Sample Data Analysis ................................................................ 8-39 Call Elements KPI Extraction................................................................ 8-40 Call Records Report ............................................................................... 8-41 KPI Extraction – What Did We Learn? ................................................. 8-42 Section 9: Closing................................................................................... 9-1 For More Information ESG .......................................................................................... 9-2 CDMA University........................................................................ 9-3 Section 10: Appendix - CDMA2000 Parameters Reference ........... 10-1 Topics (10): CDMA2000 Parameters Reference.................................. 10-2 Access Parameters ................................................................................. 10-3 Registration Parameters ........................................................................ 10-7 Open Loop Power Control Parameters ............................................... 10-10 Forward Closed Loop Power Control Parameters .............................. 10-11 Reverse Closed Loop Power Control Parameters ............................... 10-18 Soft Handoff Parameters ..................................................................... 10-20 Mobile Searching Parameters .............................................................. 10-24


© 2005 QUALCOMM Incorporated



Section 1: Course Overview and Software Installation

Course Overview and Software Installation1

SECTION

Section 1-1

Notes


1-1





What Will You Learn in the Seminar?

What will you learn in this CDMA2000 1X Network Characterization Seminar?

• The purpose of this seminar is to provide practical hands-on experience with real datasets from live networks. During the seminar, you will:– Review some network data sets.

– Gain a working knowledge of the activities performed during typical system testing and periodic system audits.

Performance Objectives:• After this seminar, you should be able to:

– Examine a snapshot of your own network.– Decide whether your network is operating well.

Section 1-2

Notes


1-2





Topics (1): Sections in This Course

1. Course Overview and Software Installation2. Network Characterization Process Overview3. The Network Planning Stage4. Reviewing Network Status5. Reviewing CDMA2000 Parameters6. Collecting Performance Data7. Post-Processing8. KPI Extraction9. Closing10. Appendix: CDMA2000 Parameters Reference

Section 1-3

Notes


1-3





Contents of the Course CD

This course CD contains additional files that can be invoked interactively from the presentation:

Type of file Filename extension

Required or optional programs to open the file

Screen snapshots produced by various analysis software tools used in preparation of this course

BMP Microsoft Paint or similar graphics utility program

TatukGIS mapping project files TTKGP TatukGIS Viewer, free mapping tool

Spreadsheet files XLS Microsoft Excel or Excel Viewer

Skip This Section

The course presentation contains links to invoke the program and data files. Depending on the security level settings of your presentation software, when you click a link, a window might appear informing you of potential security problems. This is normal and does not mean that the data or executable files included on the course media contain any viruses.

Section 1-4

Notes


1-4





Installing TatukGIS Viewer

TatukGIS Viewer is a free mapping utility, made available courtesy of www.tatukgis.com.

• To install the TatukGIS Viewer, run the installation program and follow the installation prompts.

– For questions, refer to the TatukGIS Viewer User Manual.

• To view TatukGIS project files on your computer during the seminar, you must create an association between the project file extension (TTKGP) and the TatukGIS Viewer program.

– To do this in Windows XP, click Start Settings Control Panel, then double-click Folder Options and select the File Typestab, as shown on the next slide.

Skip TatukGIS Installation

Section 1-5

Notes


1-5





Creating the TatukGIS File Association

Click New. Then in the File Extension field, type TTKGP. Then click OK.

Section 1-6

Notes


1-6





Creating the TatukGIS File Association (continued)

Next, click Change. If no previous association exists for the TTKGP file extension, a window opens saying that the file cannot be opened.

Select “Select the program from a list”and click OK.

Section 1-7

Notes


1-7





Creating the TatukGIS File Association (continued)

If the TatukGIS Viewer is listed, select it.

If not, click Browse..., then navigate to the installed TatukGIS Viewer (installed by default in C:\ProgramFiles\TatukGIS\Viewer\viewervwr.exe)

Click OK.

Section 1-8

Notes


1-8





Testing Interactive Data Content

Now click the following links to test that your computer is properly set up for the interactive content:

• TatukGIS Viewer project example

• Screen snapshot example

• Spreadsheet file example

Section 1-9

Notes


1-9



Comments/Notes


1-10





Section 2: Network Characterization Process Overview

Network CharacterizationProcess Overview2

SECTION

Section 2-1

Notes


2-1





Topics (2): Network Characterization Process Overview

• The Network Characterization Process

• Definition of Network Characterization

• Key Performance Indicators (KPIs)

• When is Network Characterization Performed?

• Initial / Periodic Characterization Steps

• Optimizing and Maintaining QoS

Section 2-2

Notes


2-2





Section Learning Objectives

Define Network Characterization.

Define Key Performance Indicators.

List several different types of KPIs.

Explain when Network Characterization is performed.

List the steps in the Network Characterization process.

Section 2-3

Notes


2-3





The Network Characterization Process

Voice Network Characterization

Delay, waiting for periodic repetition, waiting for

changes in the network (increased loading, etc.).

YES

Collecting Performance Data

Post Processing

KPI Extraction

Target KPI

Passed?

Network PlanningDetailed Design

Installation

Installation Verification

Drive Route Selection

Analysis to determine corrective actions.

Implementing corrective actions.

Network Optimization

NO

Analyze Forward Link Scan, implement

corrections.

NO

Review of NetPlan Output

Review of Network Status

Perform Forward Link Scan

Correction Needed?

YES

Section 2-4

Notes


2-4





Definition of Network Characterization

• Network characterization collects large sets of performance data over large areas of the system to compute statistically significant QoS values.

• The resultant QoS values are used to verify compliance with target values, as well as to detect trends of changes of QoS values in order to plan corrective actions or expansion of the system.

“Network Characterization is the process of determining whether the deployed CDMA system satisfies the required Quality of Service (QoS).”

Section 2-5

Notes


2-5





Key Performance Indicators − Basic KPIs

Key Performance Indicators (KPI) are variables used for QoS evaluation. Basic KPIs directly reflect end-user Quality of Service:

• Service Availability – area provided with adequate Forward and Reverse links, so that users can obtain service.

• Voice Quality – measures the quality of the link in terms of how it affects a user’s ability to understand the end-to-end voice.

• Dropped Call Rate – reliability of a connected Traffic Channel.• Mobile Originated Call Success Rate and Duration – reliability of

calls being made by the mobile users, and the length (i.e., delay) of the call setup.

• Mobile Terminated Call Success Rate and Duration – reliability of calls being made to the mobile users, and the length of the call setup.

Section 2-6

Notes


2-6





Key Performance Indicators − Capacity KPIs

Capacity KPIs affect the economy of the system operation, and thus the service provider:

• Forward Link Capacity – how many voice channels can the Forward link operate with sufficient voice quality; how much capacity is left for data users.

• Reverse Link Capacity – how many voice channels can the Reverse link operate with sufficient voice quality; how much capacity is left for data users.

Note that some Basic KPIs and Capacity KPIs are inversely related; it is possible to improve Capacity KPIs at the expense of Basic KPIs.

Section 2-7

Notes


2-7





Key Performance Indicators −CDMA/Secondary KPIs

The Basic and Capacity KPIs are affected by a set of CDMA/Secondary KPIs:

• Mobile Receive Power• Mobile Active Set Pilot Strength• Mobile Transmit Power• BTS Traffic Channel Power• Forward Link Frame Error Rate• Reverse Link Frame Error Rate• Access Attempt Success Rate and Duration• Active Set Size

Section 2-8

Notes


2-8





Key Performance Indicators −Dependencies Section 2-9

Notes


2-9





When is Network Characterization Performed?

Network Characterization is performed in two distinctive phases of network operation:

1. Initial network characterization – typically performed as part of the Acceptance Test.

2. Periodic network characterization – performed either on a fixed schedule, or when changes occur in the network (e.g., change of network loading; build-out; changes in equipment, both hardware and software). The Periodic Network Characterization differs from the Initial Network characterization by not including the Review of Network Planning and Review of Network Status steps.

During network optimization, the network characterization step is repeated multiple times after each change, until the target performances are met.

Section 2-10

Notes


2-10





Initial Network Characterization Steps

Initial Network Characterization starts after the system has been installed and the installation has been verified.

• Review of Network Planning − Network planning creates output from which the network characterization team can learn about predicted coverage, sector dominance, and so on. In turn, data collected during network characterization can help fine-tune the network planning (e.g., propagation models), so that the networkplanning accurately reflects the system before the next round ofsystem changes needs to be planned.

• Review of Network Status − Ensures that the system is stable before performance data is collected. The collected performance data can be invalidated by changes to system configuration—hardware or software—or by unexpected user voice or data loads.

Section 2-11

Notes


2-11





Initial and Periodic Steps

The following steps are common to both initial and periodic Network Characterization:

• Collecting Performance Data − determines the QoS experienced by the end users. Testing is performed in all areas of the system design, including the areas that should have coverage. The collected set of performance data allows the QoS to be computed, and provides sufficient input for detailed analysis if the measured QoS does not satisfy target values.

• Post-processing − extracts the performance data from binary log files, as typically collected by diagnostic monitors, into a set of mapping plots, histograms, and charts to evaluate whether targetQoS has been satisfied.

• KPI Extraction − evaluates post-processing outputs and determines whether any of the QoS targets are not being met.

Section 2-12

Notes


2-12





Optimizing and Maintaining QoS

• If any of the target QoS values are not being met:– Perform more detailed analysis of the collected data to determine corrective

action. CDMA University’s CDMA2000 Voice Network Optimization course addresses this detailed analysis.

• After implementing any corrective actions:– Repeat the sequence, including the collection of performance data. The

collection might be on a smaller scale, depending on whether the corrective action was localized to a small subset of the network.

– For changes affecting the whole network (such as changes to some of the basic CDMA parameters), repeat the collection over the whole system coverage area.

• After the measured QoS is achieved:– The Network Characterization activity is typically suspended, but not stopped.

It is either repeated periodically, to ensure no degradation of QoS, or started again when the system configuration changes, new components are installed in the network, old components (including system software) are replaced by new ones, system load increases, or user complaints indicate an unexplained degradation of the QoS.

Section 2-13

Notes


2-13





Network Characterization Process Overview –What Did We Learn?

What is Network Characterization?

What are Key Performance Indicators?

What are several different types of KPIs?

When is Network Characterization performed?

What are the steps in the Network Characterization process?

Section 2-14

Notes


2-14





Section 3: The Network Planning Stage

The Network Planning Stage3

SECTION

Section 3-1

Notes


3-1





Topics (3): The Network Planning Stage

• How Network Planning and Network Characterization are Related

• Network Planning Issues

Section 3-2

Notes


3-2






Explain how the network planning and network optimization processes are interrelated.

List some important limitations of network planning tools.

Section 3-3

Notes


3-3





How Network Planning and Network Characterization are Related

Network Planning and Network Characterization are related and depend on each other in the following ways:

• The design criteria (coverage area, desired Pilot Ec/Io power) that are used as input to Network Planning serve as input into Network Characterization as well.

• Expected user density and its distribution throughout the coverage area serves as input into Network Planning. Any corrective action identified during Network Characterization needs to take the user density into account.

Section 3-4

Notes


3-4





How Network Planning and Network Characterization are Related (continued)

• Test engineers can use network planning output to familiarize themselves with the system configuration, expected coverage area, and serving sectors throughout the coverage area.

– This assumes that the network planning output is updated to match the configuration actually being deployed.

– Typically system installation includes some deviation from the initial network planning, due to real estate limitations, zoning rules, or prices for different locations within the acceptable cell size.

• A prediction of sector dominance (plot of server PN offset) can be used to determine suitable locations to test sector operation, proper sector-antenna cabling, and handoff areas.

– This is useful during a pre-test of the network deployment, before the complete Collection of Performance Data step is started.

Section 3-5

Notes


3-5





How Network Planning and Network Characterization are Related (continued)

• Network planning can estimate problematic areas, as well as areas with predicted good coverage. This information can be used for early testing of predicted problematic areas. Be careful, however, because network planning predictions are not 100% reliable.

• Network planning can simulate the effects of increased load on both Forward and Reverse links.

• Data collected during Network Characterization can be used to fine-tune the predictions produced by Network Planning. This is desirable because it allows the network planning tool to have an up-to-date model of the network and signal conditions.

• A network planning tool that is well tuned to match current system conditions can serve as a “what-if” evaluation tool for various corrective actions being considered.

Section 3-6

Notes


3-6





Network Planning Issues

• Network Planning is a prediction tool. Even with fine-tuned propagation models, it is only an estimate of the real-life conditions.

• Network Planning’s input data (e.g., terrain data, clutter, user density distribution) has limited precision.

• Regardless of whether the Network Planning predicted good or badcoverage, the whole target coverage area needs to be sampled during a complete Network Characterization process. This is because theNetwork Planning determination of good vs. bad coverage is subject to the imprecision of the input data and the varying reliability of network planning tools.

• The deployed system’s configuration can differ from the Network Planning output.

When using a Network Planning tool and its output, be aware of the following important issues:

Section 3-7

Notes


3-7





The Network Planning Stage –What Did We Learn?

What are some key differences between network planning and network optimization?

How are the two processes interrelated?

What are some important limitations of network planning tools?

Section 3-8

Notes


3-8





Section 4: Reviewing Network Status

Reviewing Network Status4

SECTION

Section 4-1

Notes


4-1





Topics (4): Reviewing Network Status

• Why Review Network Status?

• Network Status Issues that Invalidate Network Characterization

• Network Status Tests

Section 4-2

Notes


4-2






Explain what a review of network status can accomplish.

Identify some network status issues that can invalidate network characterization.

List the steps that must occur before a network is ready for collection of performance data.

Describe the elements in a Network Status Test.

Section 4-3

Notes


4-3





Why Review Network Status?

During the network characterization process, the review of network status ensures that:

• The system supports basic operations needed to enter the phase of collecting performance data: call origination, termination, and retention.

• The system configuration is known, implemented according to the design, and stable for the duration of the rest of the network characterization process steps.

Verifying proper network status is typically most important in an initial network characterization, as the network is being readied for commercial launch.

A periodic network characterization process is performed on a commercially operating network, where the status is known.

Section 4-4

Notes


4-4





Network Status Issues that Invalidate Network Characterization

What issues can invalidate the network characterization?• Sectors not emitting Forward link.• Sectors not completely installed and commissioned.• BTS hardware wired to incorrect antennas (sectors are swapped).• BTS Transmit and Receive ports wired to different Tx/Rx antennas.• BTS hardware not calibrated.• Backhaul links not operating, operating at less than planned throughput, operating with

high Bit Error Rate.• Antenna installation incorrect; improper downtilt.• BTS not configured with complete set of channel cards.• Different versions of software deployed throughout the system (different BTSs operating

different software loads), software used is not the version planned for commercial launch.• BTS operating with CDMA over-the-air parameters differing from design.• Incorrect Neighbor List configuration.• Incomplete MSC installation; inability to authorize mobiles for service.• Inoperable links between MSC and PSTN.• and many more......

Section 4-5

Notes


4-5





Network Status Tests

To ensure that a network is ready for the collection of performance data, perform the following steps:

• Review the network installation with the installation and commissioning group.• Establish procedures between groups and departments to ensure stable configuration,

and coordinate activity.• Perform a Network Status Test to verify that the network is operating well.

Because collecting performance data is a lengthy and expensive process, the network status needs to be verified before the collection process starts. The Network Status Test is a rudimentary go/no-go test consisting of the following elements:

• A stationary test to verify the mobile can register, make outgoing calls, and receive incoming calls.

• A drive test designed to enter dominant coverage provided by every sector included in the network characterization.

• Observing that sector dominance approximately matches output of network planning.• Making mobile-originated calls in every sector.• Testing handoffs between sectors while on a call.

Section 4-6

Notes


4-6





Network Status Tests (continued)

Performing the Network Status Test and processing the data can use the same collection, post processing, and KPI extraction sequences as the full network characterization procedure, with this difference:

• Scope of the drive testing is limited: for each sector we need only one dominant coverage area, and transitional areas to all neighboring sectors.

Section 4-7

Notes


4-7





Reviewing Network Status –What Did We Learn?

What can a review of network status accomplish?

What are some network status issues that can invalidate network characterization?

Which steps must occur before a network is ready for collection of performance data?

What elements does a Network Status Test contain?

Section 4-8

Notes


4-8





Section 5: Reviewing CDMA2000 Parameters

ReviewingCDMA2000 Parameters5

SECTION

Section 5-1

Notes


5-1





Topics (5): Reviewing CDMA2000 Parameters

• What are CDMA Parameters?

• Examples of Problem Parameters

• How to Review Parameters

• Setup for Parameter Extraction/Verification

• Appendix: CDMA2000 Parameters Reference

Section 5-2

Notes


5-2






List some groups of CDMA parameters.

Explain why it is important to review CDMA parameters during network characterization.

State an example of a valid parameter setting that can be hazardous to a properly functioning network.

Section 5-3

Notes


5-3





What are CDMA Parameters?

CDMA parameters affect the operation of the mobile and Base Station and ensure communication between them.

• Over-the-air parameters – values of fields in signaling messages sent from the BTS to mobiles. This is the dominant group of CDMA parameters.

• BTS parameters – parameters configured by the service provider, which control the operation of the BTS. Because only BTS operation is affected, these are not sent over the air to the mobile.

• Mobile-settable parameters – parameters programmed into the mobile, at the point-of-sale or support, or using the Over-the-Air Service Programming (OTASP).

Why review CDMA parameters?• Allowed parameter values – values that are valid in signaling messages. However, some

valid values can be hazardous in practice, because they interfere with proper CDMA operation.

• Interdependency of parameters – some parameters depend on the value of others.

• Outdated functionality – some parameters refer to functionality that has been replaced in newer versions of CDMA standards, or has become outdated.

Section 5-4

BTS Parameters

BTS parameters are proprietary and specific to CDMA infrastructure vendors; therefore, they are not discussed in this course.


5-4





Examples of Problem Parameters

Examples of CDMA parameters values that are valid, yet unsuitable:• T_ADD

– T_ADD controls the threshold of Pilot strength for addition of a Pilot to the Candidate Set. The valid range is 0 – 63, which translates to Pilot strength Ec/Io between 0 and -31.5 dB. On an unloaded sector, without any other interference, the Pilot strength is approx. -2 dB Ec/Io. With loading and interference from other sectors, the Pilot strength decreases further. So a T_ADD value between 0 and -2 dB would preclude any soft handoffs from occurring.

– The searcher module in the mobile shows a “noise floor”: a Pilot strength value measured even in the absence of any signal from the measured PN offset. The noise floor depends on the length of the integration phase of the searching; normally it is approx. -20 to -22 dB Ec/Io. Therefore, setting the T_ADD parameter to a value between -22 and -31.5 dB would result in all Neighbor and Remaining Set Pilots being added to the Candidate Set, since the noise floor is above the T_ADD.

• REG_PRD – REG_PRD specifies the timer-based registration period. The allowed range is 29-85. The

smallest value, 29, translates to a registration period of 10.5 sec. With approx. 700 users within the coverage of a single sector, this translates to 700/10.5 = 66 registrations per second, which would overload the Access Channel, as well as very likely overload the VLR. In addition, the mobiles would deplete their batteries quickly due to the high duty cycle of transmitting the Registration message and waiting for the acknowledgment.

Section 5-5

Notes


5-5





How to Review Parameters

The review of CDMA parameters is based on one of several sources:

• Manual review of configuration screens in the Operations Administration and Maintenance (OA&M) station – not recommended due to the potential for human error.

• Exporting the parameters from the OA&M station.• Parsing mobile log files – this allows viewing of OTA CDMA

parameters only.

Automation of CDMA parameters review• The commercial CDMA post-processing tools do not currently support

an automated execution of CDMA parameter value checking. Custom ad hoc scripts and Excel spreadsheets are used instead.

Section 5-6

Notes


5-6





Setup for Parameter Extraction/Verification Section 5-7

Notes


5-7





Reviewing CDMA2000 Parameters –What Did We Learn?

What are some types of CDMA parameters?

Why is it important to review CDMA parameters during network characterization?

What is an example of a valid parameter setting that can be hazardous to a properly functioning network?

How can you review parameters?

Section 5-8

Notes


5-8





Section 6:Collecting Performance Data

Collecting Performance Data6

SECTION

Section 6-1

Notes

Section 6: Collecting Performance Data

6-1





Topics (6): Collecting Performance Data

• BTS/BSC/MSC Logging– MSC Call Detail Records– Logging BTS Rx Power

Loaded SystemUnloaded System

– Reverse Link Power Control– Access & Reverse

Fundamental Channel Search Window Size Logging

– BTS/BSC Logging for Neighbor List Management

• Mobile Logging– Commercially Available Tools

CAITSpirent

– Forward Link ScanningRole in Network OptimizationRequired FeaturesBasic Scanner TypesOverriding OTA Parameters

– Mobile Logging TestsReceive Power TestTransmit Power TestFER TestForward/Reverse Power Control Loop TestsAccess Statistics TestCall Success TestsAutomating Call ActivityTest Units vs. Tests Matrix

Section 6-2

Notes


6-2






Describe the kinds of parameters that are logged by the BTS/BSC/MSC.

Explain how infrastructure logging differs from mobile logging.

List some commercial mobile logging tools.

Explain why Forward link scanning is crucial to network characterization.

Section 6-3

Notes


6-3





Collecting Performance Data –BTS/BSC/MSC Logging

BTS/BSC/MSC Logging• Supporting Utilities

• Data Example Set

• Configuration

• GUI Viewer

• MSC Call Detail Records

• Logging BTS Rx Power

• Reverse Link Power Control

• Access & Reverse Fundamental Channel Search Window Size Logging

• BTS/BSC Logging for Neighbor Lists Management

Section 6-4

Notes


6-4





BTS/BSC/MSC Logging

BTS/BSC/MSC Logging (Infrastructure Logging)Logging support for these elements of a CDMA system is vendor-specific and proprietary. The information available in these devices is crucial in operating the CDMA system, because it:

• Verifies that the system offers adequate Quality of Service to the user.

• Monitors capacity and predicts necessary expansion.

• Identifies areas of the system with problematic service, which need attention.

• Is the only source of several important Key Performance Indicators, not available from mobile logging (for example, Reverse link Frame Error Rate).

• Can compare performance before and after changes are implemented in the network (e.g., new system software/hardware, system parameter changes, cell site additions, expansion for new CDMA channels).

• Supports mobile drive testing by providing a view into the infrastructure side of the Over-the-Air connection.

Section 6-5

Notes


6-5





BTS/BSC/MSC Logging (continued)

In contrast to mobile-drive-test logging, infrastructure logging:

• Includes a large amount of performance data from a large group of users. This is crucial for collecting statistically significant samples, to satisfy confidence intervals.

• Collects data:

– 24/7, thus allowing comparison between loaded and unloaded periods.

– From users in all parts of the system, not restricted to areas included in drive testing.

– From users in buildings or in areas unavailable for drive testing (such as pedestrian zones).

• Often has significantly lower costs for the data collection.

Section 6-6

Notes


6-6





Infrastructure logging generates a large amount of data. Using that data efficiently requires supporting utilities such as the following:

• Configuration tool – to enable logging and select logging data• Database – to store logged data• Backup system – to archive logged data• Interactive GUI (graphical user interface) viewing utility – to display

logged data and extracted KPIs• Utility to export the data – for further processing in other software

utilities, using standard file formats (e.g., spreadsheet file format, text file format / comma-separated-values, XML)

BTS/BSC/MSC Logging – Supporting Utilities

The role of infrastructure logging and supporting tools is crucial in operating a CDMA system; in fact, it should be part of the vendor selection process before the CDMA system is purchased. Demonstration of infrastructure

logging support should be part of the system acceptance procedure.

Section 6-7

Notes


6-7





Over-the-Air interface:• Erlang load of sectors in calls• Erlang load of sectors in Walsh code

usage• Average call duration• Call drop rate• Distribution of different call drop

reasons• Number of call setups• Call setup success rate for mobile-

originated and mobile-terminated calls• Reverse link FER• Reverse link Rise-Over-Thermal• Transmit power of the sector• Number of soft handoffs• Active Set size distribution

BTS/BSC/MSC Logging – Data Example Set

Over-the-Air interface (continued):• Reverse link Eb/Nt setpoint distribution• Reverse link Eb/Nt reading distribution• Reverse link searcher timing distribution• Per-channel transmit power distribution• Paging channel load for different

categories (overhead, paging, call setup, SMS, DBM) and per-paging slot

• Percentage of page-repeats

Resource utilization/performance• CPU loading percentage• Memory utilization• Backhaul link utilization for different

categories (voice/data/signaling/internal system messaging)

Example set of infrastructure logging data

Section 6-8

Notes


6-8





Configuring infrastructure logging• The amount of data collected in the infrastructure can affect the

operation of the system, due to the following limitations:– Available processing power (CPU)– Available memory – Available bandwidth on connections within the system (backhaul links as well as

physical links within the system)

• To avoid affecting system performance, configure infrastructure logging specifically for the set of information needed.

• Typically a set of Basic KPIs is computed and logged 24/7, with additional detailed logging available, including:– Detailed, timed based logging for a smaller set of users – these are either test

phones or phones of users that have complained about their quality of service. Such logging needs to include timebased (vs. just a summary) samples of basic parameters as well as signaling messages exchanged with the mobile.

– Logging a specific set of parameters, which cannot be logged 24/7 along with other parameters without affecting system resources.

BTS/BSC/MSC Logging – ConfigurationSection 6-9

Notes


6-9





GUI ViewerVisualizing the collected logged data requires a flexible GUI viewer. The viewer might support the following features:

• Charting of time-based variables, supporting multiple variables on a single graph.

• Filtering of information sources (for example, show aggregated data for a user-configured group of cell sites/sectors).

• Zooming in time to a particular time interval.

• Displaying different time intervals and sources side-by-side for easy comparison.

• Displaying data on maps, to obtain a quick view of an area.

• Zooming of mapping views.

• Integration into a chain of tools (SQL databases, report generation tools, export utilities) to support logging data processing.

BTS/BSC/MSC Logging – GUI ViewerSection 6-10

Notes


6-10





MSC Call Detail Records (CDR)To support billing, a CDMA system collects Call Detail Records.

• Because they are usually collected for all user activity on the system, CDRs are a valuable source of information for generating load and Quality of Service statistics.

• To serve this purpose, the CDRs must include extra information:– Detailed call termination reason– Originating sector of the user activity– Terminating sector

• If the CDMA system supports a near-real time access to the CDR database, an interactive GUI application showing the call activity and success rate can be used to monitor the health of the system.

BTS/BSC/MSC Logging – Call Detail RecordsSection 6-11

Notes


6-11





Logging BTS Rx Power (“Rise-over-Thermal”)Logging BTS Rx Power is crucial for obtaining information on:

• Reverse link load• Behavior of Reverse link power control• Reverse link interference patterns (external or CDMA mobiles not correctly power-

controlled)

BTS Rx Power – Unloaded ConditionEstablishing the Rx Power received by the BTS during an unloaded condition (verified by monitoring call activity, or enforced by temporarily disabling mobiles) establishes a baseline value, to which the values read in a loaded condition are compared.

While this value is often referred to as the thermal floor, it consists of• Thermal noise energy in the CDMA band• Noise figure of the LNA• Contribution to the thermal noise of repeaters within the sector coverage• Constant interference sources

BTS/BSC/MSC Logging – BTS Rx PowerSection 6-12

Notes


6-12





BTS Rx Power – Loaded SystemLogging the BTS Rx Power over time allows one to monitor:

• Reverse link loading

• Behavior of the Reverse link power control

• Behavior of the Reverse link admission algorithm implemented in the BTS

Several “rule of thumb” values:• A rise of Rx Power by 3 dB over “unloaded Rx Power” equates to

approximately 50% loading of the Reverse link.

• A rise of the Rx Power by 1 dB equates to a Reverse link load increase of approximately 10%.

• A CDMA2000 Reverse link is typically operated at up to 75-80% of pole (an approximately 6 dB rise of Rx Power over the unloaded condition).

BTS/BSC/MSC Logging –BTS Rx Power (continued) Section 6-13

Notes


6-13





BTS/BSC/MSC Logging –RoT Noise and Rx Loading

Rise over Thermal Noise Due to Loading on the Reverse Link

01

2345

6789

10

10%

20%

30%

40%

50%

60%

70%

80%

90%

Percentage of Pole

dB o

f Noi

se R

ise

Section 6-14

Notes


6-14





BTS/BSC/MSC Logging –Reverse Link Power Control

Reverse Link Power Control

Two separate areas relate to Reverse link power control:

• Algorithms implemented in the BTS/BSC by the infrastructure vendor

• The set of configurable parameters affecting the Reverse link power control

The logging in the BTS/BSC must provide information to judge both the algorithms and parameter values.

Section 6-15

Notes


6-15





BTS/BSC/MSC Logging –Reverse Link Power Control (continued)

Typical set of Reverse power control related parameters:• Initial Reverse link Pilot Eb/Nt setpoint value• Minimum and maximum Reverse link Pilot Eb/Nt setpoint values• Step sizes for Pilot setpoint value increment, based on received frame

errors and sequence of errors• Step size for Pilot setpoint value decrement, based on received frames

without errors

Set of logging variables helpful in evaluating and tuning Reverse link power control:

• Histogram of Reverse link Pilot Eb/Nt measurements• Histogram of Reverse link Pilot setpoint values• Histogram of the difference between Reverse link Pilot Eb/Nt

measurement and setpoint

Section 6-16

Notes


6-16





BTS/BSC/MSC Logging – Access & Reverse FCH Search Window Size Logging

Access & Reverse FCH Search Window Size LoggingThe search window size on the Access Channel and Fundamental Channel (FCH) controls the range of timing during which the BTS channel card searches for multipath peaks of the Reverse link energy received at the BTS. The following factors affect the timing:

• Sector radius – the expected coverage area served by the sector determines the roundtrip delay: the delay of the Reverse link signal (both Access and FCH) arriving at the BTS relative to the timing of the BTS.

• The morphology of the sector – typically rural areas provide multipaths with wider spread between the peaks. Mountain areas and hills provide more sources of multipath peaks with significant energy and delay, compared to flat areas. Large manmade structures can behave like mountains/hills, often with large reflections.

• The timing of the mobile – which in turn depends on the Forward link timing experienced by the mobile. Configuration with unequal propagation of sectors in soft handoff requires an adequate increase in the search window size (i.e., a boomer sector providing dominant Forward link power from afar, and a near-BTS demodulating the Reverse link).

Section 6-17

Notes


6-17





BTS/BSC/MSC Logging – Access & Reverse FCH Search Window Size Logging (cont.)

If the search windows are set to values lower than the sector conditions require, the BTS channel serving the Reverse link channel cannot detect any multipath peaks, or fails to detect significant peaks, if they fall outside of the search window. The results are:

• Failure to detect Access probes completely, or delayed detection of Access probes (the mobile is sending more Access probes than otherwise would be necessary).

• The undetected Access probes serve as a source of Reverse link interference, causing active mobiles to compensate by increasing Tx Power. Mobiles operating close to maximum Tx power can experience frame errors on the Reverse link because they are unable to compensate for the interference.

• Failure to establish FCH in a call setup, or during channel acquisition after a soft handoff has been set up.

• High Reverse link Frame Error Rate due to significant peaks of the Reverse FCH not being detected.

• A mobile operating on a FCH with inadequate search window size can provide Reverse link interference similar to the undetected Access probes. The Reverse link power control will ask for more Tx Power from the mobile, yet the energy is not detectable by the BTS, and turns into interference.

Section 6-18

Notes


6-18





BTS/BSC/MSC Logging – Access & Reverse FCH Search Window Size Logging (cont.)

Effects of search window sizes being larger than necessary:• The search performance of the channel card might be affected, thus delaying

detection of new multipath peaks. • The delayed detection can increase Reverse link FER, and again cause the

mobile to become an interferer on the Reverse link of the BTS.• The effect is more significant with older generations of BTS channel card chips

– newer generations offer improvements in searching performance.

How to evaluate search window size configuration:• A combined representation of multipath peak energy and timing is needed.

The energy of the peak is evaluated, so that search windows are not expanded unnecessarily based on relatively weak multipath peaks.

• Since logging all searcher results is impractical due to the large amount of information, several Binning approaches can be used:

– Timing-based Binning of all multipath peaks above a certain threshold of Reverse link Pilot Ec/Io.

– 2-dimensional Binning based on both timing and energy of the multipath peak.

Section 6-19

Notes


6-19





BTS/BSC/MSC Logging – BTS/BSC Logging for Neighbor List Management

Correct Neighbor Lists are necessary to ensure high Quality of Service (QoS) in a CDMA system. There are two possible kinds of Neighbor List problems:

• Missing Neighbor List entries. These can cause:– Dropped calls– High Forward link Frame Error Rate (FER)– Idle handoff failures

• Unnecessary Neighbor List entries. These can cause:– Slower mobile searching performance, because of searching for PN offsets

that are not present strongly enough while in the coverage of the current sector. The decreased searching performance has the same effect as missing list entries

– Neighbor List size limits being exhausted by the extra unnecessary entries, thus preventing needed entries from being included.

Section 6-20

Notes


6-20





BTS/BSC/MSC Logging – BTS/BSC Logging for Neighbor List Management (continued)

Neighbor List management can be performed by means of mobile logging. However, this requires that the following challenges be met:

• The drive test must include all possible user locations.

• Special Pilot scanners must be used – a regular mobile cannot be used because of a low frequency of Remaining Set searches (typically a Remaining Set PN Offset approximately once per minute).

As a result, mobile drive testing for the purpose of Neighbor List management is expensive, time-consuming, and often incomplete.

Section 6-21

Notes


6-21






BTS/BSC logging can address the Neighbor List management by logging data from Pilot Strength Measurement Messages (PSMM) and creating statistics for Active Sets:

• PSMM messages that include strong searcher results for a Remaining Set PN offset can indicate a missing Neighbor List entry.

• The timing information reported for each Pilot in the PSMM can be used to verify whether there is sufficient reserve in the Neighbor/ Remaining Set search window size.

• Active Set statistics need to show how many times members of Neighbor Lists are actually used in an Active Set. If there are members that have a zero of very small participation in Active Sets compared to other PN offsets in the Neighbor List, they are likely cases of unnecessary Neighbor List entries.

Section 6-22

Notes


6-22






Neighbor List management based on BTS/BSC logging has the following benefits over mobile-based drive testing:

• It contains statistics for all locations frequented by users.

• Having many users performing Remaining Set searches in all user-frequented locations increases the otherwise low Remaining Set search frequency of a single user.

• Can be operated around the clock, thus responding quickly to changes in the network that affect Neighbor List configuration.

Section 6-23

Notes


6-23





Collecting Performance Data –Mobile Logging

Mobile Logging• Commercial Tools

• Forward Link Scanning

• Mobile Logging Tests

Section 6-24

Notes


6-24





Mobile Logging –Commercially Available Logging Tools

When selecting a logging tool to collect mobile logging data, consider the following major features:

• Compatibility – with the test mobile used in the network characterization.• Logged variable configurability – the set of logged variables must be

selectable, so that the full logging chain reliably logs selected data, and reliability is not affected by logging irrelevant data.

• Support for technologies used – depending on the network, technologies used and support for multi-mode mobiles, the logging tool might need to support multiple technologies (cdmaOne, CDMA2000, EV-DO, GSM, WCDMA).

• Vendor support – for multiple test mobile vendors.• Backward compatibility – with older generations of mobiles still supported on the

CDMA network.• Automation of call activity – any tests depend on the mobile periodically setting

up and tearing down voice calls, or keeping a succession of calls until they fail; the logging tool must be able to automate these actions, so they do not have to be performed manually.

Section 6-25

Notes


6-25





Mobile Logging – Commercially Available Tools (continued)

Logging tool features (continued):• GPS receiver support – GPS location data associates performance data and events

with their collection location. The GPS location is used mainly in plotting key performance indicators and abnormal events on a map.

• Support for multiple mobiles per computer – allows for a smaller overall logging configuration.

• Display – of main call state and CDMA parameters, and GPS information; this allows the test engineer to monitor the progress of the test.

• Alarms – to attract the drive-test crew’s attention if some of the interfaces fail, or if the call activity desired for the test has failed.

• Scripting – to invoke text files with commands to automate logging, call activity, or mobile configuration.

• Software automation – can use other programs to automate logging, call activity, and mobile configuration; also receive logging data from the logging program.

• Log file viewing – support for view and replay of created log files.• Localization – for languages other than English.• Economical – both in terms of purchase price and maintenance support.

Section 6-26

Notes


6-26





Mobile Logging –Commercially Available Tools: CAIT

QUALCOMM’s CDMA Air Interface Tester (CAIT) is the de facto industry standard CDMA logging tool. CAIT attributes:

• Fully supports the wide range of mobiles based on several generations of QUALCOMM’s Mobile Station Modem (MSM) chips.– Supports all technologies implemented in the MSM chip in the test mobile.– Supports only mobiles based on QUALCOMM MSM chips. The logging

support implemented in the MSM system software must be unchanged from the MSM system software delivered by QUALCOMM (other than addition of new, proprietary logging data by the mobile vendor).

• Configures the logging data via logmask – a set of on/off bits for logging various logging messages.

• Is fully backward-compatible with all protocol revisions (P_REV) of mobiles and CDMA infrastructure.

• Automates voice call activity via the Call Manager.

Section 6-27

Notes


6-27





Mobile Logging –Commercially Available Tools: CAIT (continued)

CAIT attributes (continued):• Supports multiple mobiles via a single computer, subject to computer

resources (CPU, memory) available. • Supports many views of main CDMA parameters and mobile status.

The detailed information available is suitable even for development-level troubleshooting of CDMA networks and terminals.

• Supports GPS receivers based on NMEA interface standard.• Generates visual and audible alarms, which are user-configurable.• Supports basic text-based scripting.• Supports software automation via industry-standard COM interface.• Supports opening and parsing the binary logging files and saving them

as text; also supports full replay of the log files, duplicating all views available during drive testing.

• Is available in English only.

Section 6-28

Notes


6-28





Mobile Logging –Commercially Available Tools: Spirent

Spirent Universal Diagnostics Monitor (UDM)

• Spirent’s UDM tool is chipset-independent, so it supports mobiles based on chipsets outside the QUALCOMM MSM chipset family.

• Related to the UDM product is the Universal Product Support Tool (UPST).

• Visit www.spirentcom.com for more information.

Section 6-29

Notes


6-29





Mobile Logging –Forward Link Scanning

Forward link scanning is used to collect data on two major aspects of the Forward link coverage:

• Pilot strength of all sectors• Receive power

The data is used to determine:• Coverage of the Forward link• Adequate Pilot strength• Correct Neighbor List configuration• Optimal search window sizes• Soft handoff overhead• Correct sector Pilot timing

Section 6-30

Notes


6-30





Forward Link Scanning –Role in Network Optimization

• Forward link scanning plays a CRUCIAL role in network optimization and characterization!

• This is due to the importance of proper Neighbor List configuration, handoff parameters, and search window sizes:– Neighbor List omissions (missing entries in Neighbor Lists) lead to dropped calls

as the mobile transits the boundary between two sectors that are not neighbors. In less dramatic cases, the omission can cause high Forward link FER.

– Neighbor Lists that include unnecessary entries lower the searching performance of the mobile (the mobile searches unnecessarily for Neighbor Set Pilots that do not contribute significant power while at the current location).

– Narrow search windows prevent the mobile from detecting Forward link multipaths with significant energy.

– Search windows that are too large degrade searching performance.

Section 6-31

Notes


6-31





Forward Link Scanning –Required Features

• Ordinary CDMA handsets cannot perform a Forward link scan.

• Forward link scan requires additional features:– Scanning of all PN offsets, based on PILOT_INCREMENT

value.

– Fast scanning – scan performance of approximately one complete scan cycle per second or better is desired.

– Ability to override Over-the-Air configuration parameters.

Section 6-32

Notes


6-32





Forward Link Scanning –Basic Scanner Types

There are two basic types of Forward link scanners:• A regular CDMA mobile modified with special system

software.– While this is a cost-effective solution, it relies on timing obtained Over-the-Air

from the CDMA system. It is therefore possible that sectors with incorrect Pilot timing will cause the scanner to shift its timing, and misinterpret searcher results. Similarly, a mobile-based scanner cannot detect a wrong CDMA system time of a network.

– QUALCOMM produces the QCTest Retriever™ Pilot Scanner.

• Dedicated hardware devices.– These devices typically include a GPS receiver, so they can verify timing

problems of every sector measured as well as system wide timing problems.

– In addition, since they do not depend on the CDMA Forward link for timing, they can continue scanning in areas with very weak Forward links (edge of coverage, local spots without adequate coverage).

Section 6-33

Notes


6-33





Forward Link Scanning –Overriding OTA Parameters

• Forward link scanners must be able to override OTA parameters. This allows the tester to modify the search without changing theOTA parameters.

• Changing OTA parameters on a live system to a set of values being considered is usually not possible, because it would affect all users.

• A minimum set of parameters that a scanner can override includesthe following:– Search window sizes – typically the search windows are expanded

compared to their OTA values. This allows the scanner to detect multipath peaks outside of the OTA search windows, which would otherwise be undetectable by the searcher.

– CDMA channel frequency – overriding the CDMA channel frequency allows the scanner to dedicate its scan to a single frequency, independent of Channel List configuration, Preferred Roaming List configuration, and System Determination logic. (System Determination is responsible for choosing a suitable CDMA channel, band, and alternatively a different technology if the currently used system is not providing reliable service.)

Section 6-34

Notes


6-34





Mobile Logging Tests

• Receive Power Test• Transmit Power Test• FER Test• Forward/Reverse Power

Control Loop Tests• Access Statistics Test• Call Success Tests• Dropped Call Rate• Automating Call Activity• Test Units vs. Tests Matrix

Section 6-35

Notes


6-35





Mobile Logging Tests − Receive Power

Receive Power Test:• Verifies adequate coverage of the Forward link, by

ensuring that the Receive power exceeds the sensitivity of the typical mobile.

– The test mobile needs to be active during the drive test, and its Sleep Mode needs to be disabled in order to provide enough samples for all locations along the test drive.

Mobiles based on QUALCOMM chip sets and system software allow Sleep Mode control by means of the CAIT program.

– The Receive Power Test is commonly combined with the Forward Link Scanning Test: the Pilot scanner devices monitor Receive power as well.

Section 6-36

Notes


6-36





Transmit Power Test:

• Verifies adequate Reverse link coverage – the limiting factor is primarily the maximum Transmit power of the mobile and secondarily the talk time of the mobile (more Transmit power consumes more battery power, lowering the talk time).

– The Transmit Power Test mobile needs to be connected in a call in order to exercise the Reverse link. Special test Service Options calls are used, typically Markov full rate or variable rate calls.

– The Mobile Transmit Power Test is typically combined with Dropped Call and FER tests on the same test mobile.

Mobile Logging Tests − Transmit PowerSection 6-37

Notes


6-37





FER Test:

• Verifies that the combined effect of Forward and Reverse link coverage and power control satisfies the Frame Error Rate threshold (typically 1% or 2%).

– To exercise both links, the FER Test mobile must be connected ina call. Special test Service Options calls are used, typically Markov full rate.

– Forward link FER can be determined by analyzing mobile logging files, while Reverse link FER needs to be determined from Base Station logging files.

– The FER test is typically combined with Dropped Call and Transmit Power tests on the same test mobile.

Mobile Logging Tests − FERSection 6-38

Notes


6-38





Forward Power Control Loop Test:• Relies on logging FCH/DCCH/SCH channel power in the BTS.

– The value is evaluated with regard to the mobility of the test mobile (stationary/pedestrian). The data provides insight into Forward link capacity.

The test mobile must be connected on the tested Traffic Channel.This test is not usually performed, because the logging of channel power in commercial CDMA infrastructures is not adequately implemented.

Reverse Power Control Loop Test:• Based on logging the transmit power of the mobile, as well as the

proportion of the power allocated to the used Reverse link channels (Pilot, FCH, DCCH, and SCH).– The test mobile must be connected on the tested Traffic Channel.

Mobile Logging Tests −Forward/Reverse Power Control Loop Section 6-39

Notes


6-39





Access Statistics Test:• Verifies that the performance of the Access Channel

is correct. – The test mobile performs a set of Accesses and the following

information is logged: their success rate and duration, and the number of sequences and Access probes required. The distribution of required Access probes is compared to the configured number (in the NUM_STEP parameter).

– The test mobile is repeating Access attempts. Mobile originated calls and mobile terminated calls are used in two different tests, because the performance of the Access attempts is typically worse than Access attempts where the mobile is responding to a BTS message.

Mobile Logging Tests − Access StatisticsSection 6-40

Notes


6-40





Mobile Originated Call Success Rate Test:• The test verifies the call success rate that the user experiences.

The success rate and duration of each call setup are logged.

– The mobile is repeatedly making short mobile Originated calls. To simulate the performance experienced by users, the mobile must enter Sleep Mode between each call.

To achieve this, insert a delay between the end of the previous call and the start of the next Access attempt.

– To correctly determine the delay experienced by the user, the call setup duration must be computed from when the user interface of the mobile instructs the call processing module to initiate the call setup.

This is so that any delays between the event starting the call and the first Access probe are properly accounted for; solutions that measure the call setup duration from first Access probe do not show the performance as seen by users.

Mobile Logging Tests −Call Success/Mobile Originated Section 6-41

Notes


6-41





Mobile Logging Tests −Call Success/Mobile Terminated

Mobile Terminated Call Success Rate Test:• Verifies the call success rate for incoming calls experienced by the

user. Success rate and duration of each call setup are logged.– A sequence of short mobile terminated calls is generated from a landline

phone, to eliminate any failures on the origination part of the call. If a landline phone is not available, a second CDMA phone can be used to initiate the calls, if it is operating in known good stationary conditions and served by a sector known to perform well.

– Because Sleep Mode and waking up from Sleep Mode can cause mobile terminated call failures, the test phone should enter Sleep Mode between the end of the previous call and the next incoming call.

To achieve this, insert a delay on the originating side after each call’s end.– To help analyze whether the BTS sent Paging messages, use an idle

phone with Sleep Mode disabled to log all Paging messages on the Paging Channel.

Ideally, feed the same RF to the test phone and the idle monitoring phone to minimize time when these two phones operate in different sectors. (Idle handoffs can occur at different times on these two test phones.)

Section 6-42

Notes


6-42





Mobile Logging Tests − Dropped Call Rate

Dropped Call Rate:• This test establishes call reliability as it is experienced by

the user. Call success rate and necessary signaling and RF coverage logging messages are logged, to allow a determination of various dropped calls.– A sequence of calls is made by the mobile. The duration of the

calls is set to match the expected average call duration.

– Alternatively, a call can be held until the call fails. The measured “time between failures” can then be converted to a call failure rate at average call duration.

Section 6-43

Notes


6-43





Mobile Logging Tests −Automating Call Activity

Automating Call ActivityThe tests just described rely on sequences of calls, with different durations and possibly delays inserted between calls.

• This would be difficult to achieve if the test phones were operated manually.

• However, for mobiles that are based on QUALCOMM’s system software, these calls can be initiated over the Diagnostics Monitor (DM) link. The DM program in CAIT supports this on its Call Manager screen, where you can automate the sequence of calls.

Section 6-44

Notes


6-44





Mobile Logging Tests −Test Units vs. Tests Matrix

Multiple tests can be performed using a single test phone:

Possible Suitable Call Drop rate

SuitableMT Call Success rate

SuitablePossibleMO Call Success rate

SuitableMobile Response Access Attempt

SuitableMO Access Attempt

PossibleSuitableREV Power Control loop

PossibleSuitableFWD Power control loop

PossibleSuitableTransmit Power

SuitablePossibleSuitableReceive Power

SuitableForward Link Scan

Idle Mobile Monitoring Paging Channel

Mobile Terminating Short Calls

Mobile Originating Short Calls

Long Voice Call Mobile

Pilot ScannerTest

• Suitable means that the test unit is suitable for the test.• Possible means that the test data can be obtained from the test unit, with possibly a reduced sample size compared to

the test unit marked Suitable for this test.

Section 6-45

Notes


6-45





Collecting Performance Data –What Did We Learn?

What kinds of parameters are logged by the BTS/BSC/MSC?

How does infrastructure logging differ from mobile logging?

What are some commercial mobile logging tools?

What are some target and example values for various mobile logging tests?

Why is Forward link scanning crucial to network characterization?

Section 6-46

Notes


6-46





Section 7: Post-Processing

Post-Processing7SECTION

Section 7-1

Notes


7-1





Topics (7): Post-Processing

• What Does Post-Processing Do?

• Post-Processing Output

• Post-Processing Utilities

• Features of Post-Processing Software

• Actix IQ Analyzer

Section 7-2

Notes


7-2






Explain what post-processing does.

Describe the output of post-processing.

List some post-processing utilities.

Section 7-3

Notes


7-3





What Does Post-Processing Do?

Post-Processing converts binary log files, which are collected during the Collecting Performance Data step, into set of output files suitable for KPI extraction.

• The KPI extraction may be performed manually, or the output files may be used as input for other analytical applications.

• Typically many log files need to be combined from multiple test phones, and collected over a period of several days.

• Log files from mobile logging and infrastructure logging (BTS and BSC log files) can be combined to present a unified view.

Section 7-4

Notes


7-4





Post-Processing Output

The output of Post-Processing contains:• Mapping plots of Key Performance Indicators over the area included in

the network characterization.

– The mapping plots are thematic maps, using color coding, symbol type and size to visualize collected KPIs. They are helpful in visualizing overall performance of the system and detecting areas of abnormal, degraded QoS.

– The mapping plots are based on Binning of the KPIs into geographical Bins, which combine a set of samples of KPIs, concentrated in a small geographical area, into a single value representing the Bin.

Binning helps to simplify the produced mapping plots compared to mapping all collected values: mapping plots that show all collected values can lead to maps with overlapping symbols, potentially hiding some important samples. Binned KPI values can be shown in a suitable grid-like fashion, since geographical Bins are points on a regular grid, separated by equal X and Y distance.

– Mapping plots are NOT suitable for determining compliance with target QoS values, because it is difficult by looking at a map to determine the percentage of Bins with a KPI value over a target value.

Section 7-5

Notes


7-5





Post-Processing Output (continued)

The output of Post-Processing also contains:

• Histograms of Binned KPIs in PDF (Probability Distribution Function) and CDF (Cumulative Distribution Function) formats. The CDF-formatted histograms in particular serve as the main input into the decision about whether the measured QoS values satisfy target requirements.

• Set of files representing KPIs in file formats suitable for import into secondary utilities: CSV (comma-separated-values), TAB (tabulator-separated-values), and spreadsheet files.

Section 7-6

Notes


7-6





Post-Processing Utilities

Post-Processing usually relies on a set of software programs/utilities that operate on the input binary log files, or on a chain of tools:

• Converters (parsers) of binary log files into human-readable text format.

• Converters of BTS/BSC log files into human-readable text format.• Command-line-driven utilities and scripts to automate post-

processing. • Integrated Post-Processing software packages that combine post-

processing and presentation• Tools to generate spreadsheet files with extracted KPI values.• Tools to compute target QoS compliance.• Report generating tools to automate generating human-readable

documentation.

Section 7-7

Notes


7-7





Features of Post-Processing Software

• Compatibility with logging files produced by the diagnostics monitor used during the Collecting Performance Data step.

• Compatibility with BTS/BSC log files.• Ability to time-synchronize mobile and BTS/BSC log files.• Ability to extract data for the set of test mobiles from the BTS/BSC log files.• Ability to synthesize events and Basic KPIs – often the log files do not contain

direct values of Basic KPIs, and the post-processing needs to identify those from other information in the log files; e.g., Call Success might be based on analyzing signaling messages exchanged between the mobile and BS.

• Binning capabilities – consisting mainly of geographical Binning. Time-based and distance-based Binning are helpful in detailed troubleshooting analysis (not considered part of the Network Characterization process).

• Exporting of Binned data – value representing the KPI for the Bin, as well as marginal values, minimum and maximum values, standard deviation. While normally a single value of a KPI is used to represent a Bin for the analysis, it is important to have access to the distribution of the KPI value samples within the Bin (e.g., it is important to highlight a Bin with a large standard deviation of Receive power, as such a Bin is not represented well with an average Receive power computation).

Section 7-8

Notes


7-8





Features of Post-Processing Software (continued)

• Filtering of Bins with too few samples – ability to eliminate from processing Binned KPI values based on insufficient sample size (e.g., computing Frame Error Rate based on a small number of frames received in the Bin can lead to artificially high Frame Error Rate).

• Interpolation of GPS data – for performance data collected while driving at medium-to-high speeds, the GPS locations should be interpolated between the GPS location samples generated by the GPS receiver (the samples are typically separated by 1 – 5 seconds).

• Automation – ability to process a complete set of log files from a command line, or a simple GUI utility. Complicated GUI utilities tend to increase the chance of an operator error, potentially invalidating the resulting data.

• Execution Performance on a typical desktop or laptop machine – the set of collected log files could be large, and the post-processing software must be able to generate output quickly. The execution performance is measured as a ratio of needed post-processing time to the duration of collection of performance data. Suitable value is 0.1 or smaller: thus a 10-hour-long collection can be processed in less than an hour.

Section 7-9

Notes


7-9





Features of Post-Processing Software (continued)

• Memory requirements, resilience to memory exhaustion – as the number of processed log files might be large, the tools need to be memory efficient. Tools requiring large amounts of memory might slow down the processing dramatically (when hard disk space is used for virtual memory), or crash the program. Resilience to running out of memory requires the tools to write out to disk data processed so far, and restart processing by reading the data back in.

• Incremental aggregation – ability to add log files to a set of processed log files without the need to reprocess.

• Modularity – ability to import and export data from various points in the processing, instead of enforcing a single, complete processing chain with no input/output points along the chain. This helps to insert specialized scripts into the processing.

• Export of post-processed data into non-proprietary file formats.

Section 7-10

Notes


7-10





Actix IQ Analyzer

Actix IQ Analyzer (www.actix.com) is the defactostandard in CDMA 2000 post-processing:

• Integrated post-processing and GUI presentation program.

• Compatible with multiple wireless technologies – supported modules for CDMA2000, EV-DO, GSM, WCDMA.

• Compatible with logging formats on mobiles implemented with QUALCOMM chip sets and system software.

The sample data sets that we will analyze in Section 8 were created with the Actix IQ Analyzer program.

Section 7-11

Notes


7-11





Post-Processing – What Did We Learn?

What does post-processing do?

What does the output of post-processing contain?

What are some post-processing utilities?

Which CDMA 2000 post-processing tool is the de facto standard?

Section 7-12

Notes


7-12





Section 8: KPI Extraction

KPI Extraction8SECTION

Section 8-1

Notes


8-1





Topics (8): KPI Extraction

• Coverage Verification Using Mobile Collected Data: – Access Attempts– Active Set Size– Active Set Pilot Strength– Search Window Size Determination– Mobile Receive Power Test– Mobile Forward FER– Mobile Transmit Power– Call Elements KPI Extraction

Section 8-2

Notes


8-2






Identify some mobile collected data that can be used to verify coverage.

Describe the KPI extraction procedures for mobile collected data.

Explain how to analyze plots and histograms for mobile collected data.

Section 8-3

Notes


8-3





Access Attempts – Target Values

Target:Configuration parameters affecting Access attempts should ensure that:

• Access attempts succeed on both loaded and unloaded systems.• The Access procedure does not slow call setup, thus negatively affecting user

experience.• Access attempts do not generate unnecessary interference on the Reverse link.

Typical KPI values to satisfy the above requirements:• 95% of Accesses complete within a single Access sequence.• Unloaded system – 95% of Accesses complete within 1 or 2 Access probes.• Loaded system – 95% of Accesses complete within 4 Access probes.• Loaded system – 50% of Accesses require 2 or more Access probes.

An additional view of the Access attempt performance can be obtained by comparing the mobile transmit power value of the final Access probe to the average transmit power in the second second of the Traffic Channel. The Access probe transmit power should not be +5 dB stronger than the Traffic Channel transmit power value.

Section 8-4

Notes


8-4





Access Attempts – KPI Extraction Procedure

KPI Extraction Procedure:• Generate histograms of the number of Access sequences required

for the duration of the test.• Generate histograms of the number of Access probes within a

sequence required for the duration of the test.• Generate plots of the number of required Access sequences and

Access probes within a sequence.

The data should be analyzed for both loaded and unloaded systems, or for a loaded system only, because Access attempt performance degrades with increasing system load.

Currently available commercial tools do not compute KPIs related to Access attempt performance.

Section 8-5

Notes


8-5





Active Set Size –Target Values and KPI Extraction Procedure

Target Values:On a loaded system, the number of Bins with Active Set Size = 1 (i.e., no handoff occurring) should be more than 66%. The percentage of Bins with Active Set Size ≥ 4 should be less than 5% in relatively flat areas, or less than 10% in hilly areas.

KPI Extraction Procedure:• Compute Active Set Size; for example, from the Pilot Set logging

message.• Aggregate Active Set Size values in geographical Bins (typically

100x100 m).• Export Bin data to a spreadsheet program.• Count percentage of Bins above the required threshold.• Generate a plot of the Bin data to identify location with Call Setup

Duration above the required threshold.

Section 8-6

Notes


8-6





Active Set Size – Plot Example

Active Set Size Plot

Click here to view sample data plot

Section 8-7

Notes


8-7





Active Set Size – Histogram Example

Example of Active Set Size histogram generated in Excel

0100200300400500600700800900

1000

1 3 5 7More

Active Set Size

Freq

uenc

y

0.00%

20.00%

40.00%

60.00%

80.00%

100.00%

120.00%

FrequencyCumulative %

Section 8-8

Notes


8-8





Active Set Size – Histogram Example (continued)

The histogram plot and table show that only 31% of Bins have the Active Set Size less than 2. The percentage of Bins with Active Set Size ≥ 4 is approximately 7.7%.

Click here to view sample data spreadsheet

Bin FrequencyCumulative

% 1 671 31.28% 2 896 73.05% 3 413 92.31% 4 140 98.83% 5 23 99.91% 6 2 100.00% 7 0 100.00% 8 0 100.00%

More 0 100.00%

Active Set Size Histogram Table

Section 8-9

Notes


8-9





Active Set Pilot Strength – Target Values

Target Values:Target value for sufficient Forward link FER is -12 dB Ec/Io. If the log data is collected on an unloaded system, the target value needs to increase by the degradation factor of Pilot strength due to system loading: this degradation is approximately 4 dB.

System Load during test Target Value None or very low -8 dB High, maximum capacity -12 dB

Section 8-10

Notes


8-10





Active Set Pilot Strength –KPI Extraction Procedure

KPI Extraction Procedure:• Aggregate Active Set Pilot Strength samples in

geographical Bins (typically 100x100 m). Note that Active Set Pilot Strength is normally derived from Finger Pilot Strength reports.

• Export Bin data to a spreadsheet program.

• Count percentage of Bins above the required threshold.

• Generate a plot of the Bin data to identify location with Active Set Pilot Strength below the required threshold.

Section 8-11

Notes


8-11





Active Set Pilot Strength – Plot Example

Active Set Pilot Strength Plot Example


Section 8-12

Notes


8-12





Active Set Pilot Strength – Histogram Example

Example of Active Set Pilot Strength histogram generated in Excel

Section 8-13

Notes


8-13





Active Set Pilot Strength – Sample Data Analysis

The spreadsheet file shows that only 75.8% of Bins satisfy the target value of -8 dB Active Set Pilot Strength.


Section 8-14

Notes


8-14





Search Window Size Determination –Target Values

Target Values:Search window sizes need to be adequate for reliably detecting strong components of multipath from sectors providing coverage. Different methods are used for Active Set and Neighbor/Remaining Sets. This is due to different alignments of the search window timing between Active and Neighbor/Remaining Sets.

If the analysis results of the search window size fall outside of the target value, the Forward link reach is too large and should be reduced.

Example Target Values: Window Target Size Target Active Set Search Window Up to 40 chips in dense urban area;

up to 80 in rural Target Neighbor Set/Remaining Set Search Window

Up to 80 chips in in dense urban area; up to 130 in rural

Section 8-15

Notes


8-15





Search Window Size Determination –KPI Extraction Procedure

KPI Extraction Procedure:• Using log files from a Forward link scan (i.e., searcher result log

packets), generate a 2-dimensional plot of Pilot Ec/Io multipath peak power versus its time offset. Two plots are needed:

– Time offset computed from the mobile system time (this is for Neighbor/Remaining set search window size determination).

– Time offset from first significant (≥ -16 dB Ec/Io) peak of the search result.

• Observe the plots for any outliers. These could indicate signalsfrom far-away sectors propagating to unexpected distances.

• Find the search window size that reliably covers all search results with significant Pilot strength (≥ -16 dB Ec/Io).

Section 8-16

Notes


8-16





Search Window Size Determination –KPI Extraction Procedure (continued)

Caution – Searcher Noise Floor • Due to the noise floor present in searcher results,

special attention is needed when combining multiple peaks of searcher results into an overall sector Pilot strength:

– Four peaks at noise floor of –19 dB, combined together, result in a Pilot strength of -13 dB, thus generating a false Pilot detection.

• Solution: do not sum together peaks of a searcher result, where the first (strongest) peak is below a threshold value.

– Suggested threshold value: -16 dB Ec/Io

Section 8-17

Notes


8-17





Search Window Size Determination –Plot Example

Neighbor/Remaining Set search result plot

Click here to view bitmap version

Section 8-18

Notes


8-18





Search Window Size Determination –Plot Example (continued)

Active Set search window size plot

Click here to view bitmap version

Section 8-19

Notes


8-19





Search Window Size Determination –Plot Example (continued)

• The two plots on the previous slides represent the same set of Forward Scan searcher results. The difference is that:

– In the Neighbor/Remaining searcher result plot, the timing is relative to the system time of the phone.

– In the Active Set Search result plot, the timing is relative to the first (in time) peak of the search result.

• The two examples show why the search windows are centered differently:– The Neighbor/Remaining Set searches show significant Pilot strength in the range of

-18 to +22 chips.

– The Active Set searches show a spread of only 4 chips between peaks of the same Pilot.

• Search window sizes:– In the Neighbor Set/Remaining Set searcher result plot, the blue vertical lines suggest a

search window size of 60 chips, covering the time offsets of -30 to 30 chips.

– The Active Set search result plot shows a very small spread between peaks of a single search: a search window size of 20 chips would be sufficient.

Section 8-20

Notes


8-20





Mobile Receive Power Test – Target Values

Target Values:Standard minimum mobile sensitivity for a voice call, 1% FER is -104 dBm in PCS band, -107 dBm in 800 MHz band. Depending on the test configuration, additional margins need to be compensated:

Test Configuration Analysis Compensation Needed Outdoor and Indoor None – test mobile receive power identical

to user mobile Outdoor only, attenuation used to simulate building penetration loss

None – the compensation is provided via the attenuation in the test mobile setup

Outdoor only Building penetration loss

Section 8-21

Notes


8-21





Mobile Receive Power Test –Building Penetration Loss

Building penetration loss depends on building construction technology. Different parts of the network might use different values – buildings in downtown areas might use concrete, thick walls, and metal-film-covered windows, while residential buildings in suburban/urban areas might be wooden structures.

The network morphology designs provide different building penetration losses.

Section 8-22

Notes


8-22





Mobile Receive Power Test – Example Values

Example Building Penetration Loss Values:

Morphology Building Penetration Loss (dB) Dense Urban 25 Suburban 15 Rural 10 Highway (car usage only) 5 - 10

Example Target Values: Morphology Required Receive Power (dBm) Dense Urban -75 Suburban -85 Rural -90 Highway -95

Section 8-23

Notes


8-23





Mobile Receive Power Test –KPI Extraction Procedure

KPI Extraction Procedure:• Aggregate Receive Power samples in geographical Bins

(typically 100 x 100 m).


• Count percentage of Bins above the required threshold.

• Generate a plot of the Bin data to identify location with Receive Power below the required threshold.

Section 8-24

Notes


8-24





Mobile Receive Power Test – Plot Example

Receive Power Plot Example


Section 8-25

Notes


8-25





Mobile Receive Power Test – Histogram Example

Example of Receive Power histogram generated in Excel

Histogram

0

20

40

60

80

100-1

05 -96

-87

-78

-69

-60

-51

-42

Bin

Freq

uenc

y

0.00%20.00%40.00%60.00%80.00%100.00%120.00%

FrequencyCumulative %

Section 8-26

Notes


8-26





Mobile Receive Power Test –Sample Data Analysis

The network consists primarily of rural morphology; the 90% compliance of threshold value of -90 dBm was judged satisfactory.


Target Receive Power Value (dBm) Percentage of Compliance (%) -75 51 -85 78 -90 90 -95 99

Section 8-27

Notes


8-27





Mobile Forward FER – Target Values

Target Values:The target value for the Forward link FER is one of the main design criteria when designing a CDMA network. Choosing a higher target value results in lower implementation cost for the network; however, it degrades the customer Quality of Service (QoS).

For best results, the logging data should be collected when the system is in a high-load condition. High load increases BS output power, thus decreasing Pilot strength, which in turn increases mobile Forward FER. An alternative is to use an Orthogonal Channel Noise Simulator (OCNS) to generate additional BS output energy, simulating high load.

A typical target value for Forward link FER is 1 – 2%.

In addition to observing the computed FER rate, it is beneficial to consider Burst FER rate – longer error bursts generate more audible audio anomalies. A typical Burst FER target value is 4 frames or less for 90% of all error bursts.

Section 8-28

Notes


8-28





Mobile Forward FER – KPI Extraction Procedure

KPI Extraction Procedure:• Aggregate Forward link FER samples in

geographical Bins (typically 100x100 m). • Export Bin data to a spreadsheet program.• Count percentage of Bins under the required

threshold.• Generate a plot of the Bin data to identify location

with Active Set Pilot Strength below the required threshold.

Section 8-29

Notes


8-29





Mobile Forward FER – Plot Example

Forward Link FERPlot Example


Section 8-30

Notes


8-30





Mobile Forward FER – Histogram Example

Example of Forward link FER histogram generated in Excel

Section 8-31

Notes


8-31





Mobile Forward FER – Sample Data Analysis


From the spreadsheet, the following target satisfaction values are obtained:

Target FER value Percentage 1.0 71.8 1.5 90.7 2.0 93.5

Section 8-32

Notes


8-32





Mobile Transmit Power – Target Values

Target Values:Maximum output power of a mobile is typically 200 mW (23 dBm). Depending on the test configuration, additional margins need to be compensated:

Test Configuration Analysis Compensation Needed Outdoor and Indoor None – test mobile receive power

identical to user mobile Outdoor only, attenuation used to simulate building penetration loss

None – the compensation is provided via the attenuation in the test mobile setup

Outdoor only Building penetration loss

Section 8-33

Notes


8-33





Mobile Transmit Power –Building Penetration Loss

Building penetration loss depends on building construction technology.

Different parts of the network might use different types: buildings in downtown areas might have thick concrete walls and metal film covered windows, while residential buildings in suburban/urban areas might be made of wood.

The network morphology designs provide different building penetration losses.

Section 8-34

Notes


8-34





Mobile Transmit Power – Example Values

Example Building Penetration Loss Values:

Example Target Values:

Morphology Building Penetration Loss (dB) Dense Urban 25 Suburban 15 Rural 10 Highway (car usage only) 5 – 10

Morphology Required Maximum Transmit Power (dBm)

Dense Urban -6 Suburban 4 Rural 9 Highway 14

Section 8-35

Notes


8-35





Mobile Transmit Power – KPI Extraction Procedure

KPI Extraction Procedure:

• Aggregate Transmit Power samples in geographical Bins (typically 100x100 m).


• Count percentage of Bins below the required threshold.

• Generate a plot of the Bin data to identify locations with Transmit Power above the required threshold.

Section 8-36

Notes


8-36





Mobile Transmit Power – Plot Example

Mobile Transmit Power Plot Example


Section 8-37

Notes


8-37





Mobile Transmit Power – Histogram Example

Example of Transmit Power histogram generated in Excel

Section 8-38

Notes


8-38





Mobile Transmit Power – Sample Data Analysis


This cluster consists of a mixture of dense urban and suburban morphology. Many of the Bins located in the dense urban part show Tx Power over the -6 dBm threshold.

Target Transmit Power Value (dBm) Percentage of Compliance (%) -6 64.5 4 85.9 9 95.9 14 99.4

Section 8-39

Notes


8-39





Call Elements KPI Extraction

Understanding events involved in call processing is important for:

• Extracting CDMA Over-the-air parameters for parameter range verification.

• Troubleshooting QoS values that the Network Characterization determines to be below target (used in the optimization stage that follows Network Characterization).

Click here to see a list of call records and messages.

Section 8-40

Notes


8-40





Call Records ReportSection 8-41

Notes


8-41





KPI Extraction – What Did We Learn?

What are some mobile collected parameters that can be used to verify coverage?

What is the KPI extraction procedure for Mobile Forward FER? For determining search window Size?

How can plots and histograms assist in analyzing mobile collected data?

Section 8-42

Notes


8-42





Section 9: Closing

Closing9SECTION

Section 9-1

Notes

Section 9: Closing

9-1





For More Information – ESG

ESG provides technical support for CDMA operators worldwide, assisting them with voice and data network optimization.

• The QUALCOMM ESG Field Team provides operators with independent written assessments of the strengths and weaknesses of current network implementations. Recommendations are included, mentioning specific areas for network improvements.

• The QUALCOMM ESG team will work with your engineers to ensure that knowledge transfer is occurring, and can provide group lectures and hands-on workshops.

QUALCOMM’s Engineering Services Group (ESG)

Section 9-2

Notes

Section 9: Closing

9-2





For More Information – CDMA University

QUALCOMM’s CDMA University

offers the training and educational resources

you need to stay on the cutting edge of

wireless technology.

CDMA Universityhas the right CDMA

class for you.

QUALCOMM: www.qualcomm.comCDMA University: www.cdmauniversity.com/cdma/

Section 9-3

Notes

Section 9: Closing

9-3



Comments/Notes

Section 9: Closing

9-4





Section 10: Appendix − CDMA2000 Parameters Reference

CDMA2000 Parameters Reference10

SECTION

Section 10-1

Notes


10-1





Topics (10): CDMA2000 Parameters Reference

• Access Parameters

• Registration Parameters

• Open Loop Power Control Parameters

• Forward Closed Loop Power Control Parameters

• Reverse Closed Loop Power Control Parameters

• Soft Handoff Parameters

• Mobile Searching Parameters

Section 10-2

Notes


10-2





Access Parameters

ACC_CHAN Parameter description Number of Access Channels per Paging Channel

Included in: Access Parameters message Recommended value 0

Value equates to: 1 Access Channel

Discussion

Typically only one Access Channel is needed per Paging Channel. If the utilization of the Access Channel is high, evaluate the need for the increased Access Channel traffic (registration parameters, length of the Access Channel slot). Increase the number of Access Channels only if the increased Access Channel load is explained.

NUM_STEP

Parameter description Number of access probes in each access sequence Included in: Access Parameters message

Recommended value 3 – 6 Value equates to: 4 – 7 access probes

PWR_STEP

Parameter description Increase of TX power between 2 consecutive access probes Included in: Access Parameters message

Recommended value 3 – 5 Value equates to: 3 – 5 dB

Section 10-3

Notes


10-3





Access Parameters (continued)

MAX_CAP_SZ Parameter description Number of 20-ms frames in the access slot capsule

Included in: Access Parameters message Recommended value 1

Value equates to: 4 20-ms frames

Discussion

The capsule size is driven by the size of the signaling messages that need to fit into the capsule. Care must be exercised with some CDMA systems, which do not support the Origination Continuation message on the FCH; such systems might fail call setups with a long sequence of dialed digits.

PAM_SZ Parameter description Number of 20-ms frames in the access slot preamble

Included in: Access Parameters message Recommended value 3 or 1

Value equates to: 4 or 2 20-ms frames

Discussion

The length of the access slot preamble depends on the searching performance of the BTS channel card. For older generations of QUALCOMM CSM chips (prior to the CSM 5000 generation), a 4-frame preamble is required. For newer generations (CSM 5000 and up), a 2-frame preamble is sufficient.

Section 10-4

Notes


10-4






ACC_TMO Parameter description Acknowledgment Timeout

Included in: Access Parameters message Recommended value 3 – 5

Value equates to: 400 – 560 ms

BKOFF

Parameter description Maximum value of a backoff between two access sequences; actual value used by the mobile is a randomly computed value smaller than the maximum.


Value equates to: 1 – 2 access channel slots, resulting in no or 1 slot delay

PROBE_BKOFF

Parameter description Maximum value of a probe backoff delay between access probes of a sequence; actual value used by the mobile is a randomly computed value smaller than the maximum.


Value equates to: 1 – 2 access channel slots, resulting in no or 1 slot delay

Section 10-5

Notes


10-5






MAX_REQ_SEQ

Parameter description Maximum number of access sequences sent while the mobile is requesting BTS attention (i.e., not replying to a BTS message)


Value equates to: 2 – 3 sequences

MAX_RSP_SEQ

Parameter description Maximum number of access sequences sent while the mobile is replying to a BTS message


Value equates to: 2 – 3 sequences

Section 10-6

Notes


10-6





Registration Parameters

HOME_REG Parameter description Controls whether home users are to perform autonomous registrations

Included in: System Parameters message Recommended value 1

Value equates to: On

FOR_SID_REG

Parameter description Controls whether roaming mobiles from different SID networks are to perform autonomous registrations



FOR_NID_REG

Parameter description Controls whether roaming mobiles from different NID networks are to perform autonomous registrations



Section 10-7

Notes


10-7





Registration Parameters (continued)

POWER_UP Parameter description Controls whether the mobile is to perform a registration on power-up



POWER_DOWN Parameter description Controls whether the mobile is to perform a registration on power-down



PARAMETER_REG

Parameter description Controls whether the mobile is to perform a registration on changes to mobile parameters



Section 10-8

Notes


10-8





Registration Parameters (continued)

REG_PRD Parameter description Timer-based registration period

Included in: System Parameters message Recommended value 57 – 60

Value equates to: 1558 sec - 2621 sec Discussion For Wireless Local Loop systems this value can be higher

REG_DIST

Parameter description Controls registration performed based on distance from the BTS where previous registration was performed


Value equates to: Off

Section 10-9

Notes


10-9





Open Loop Power Control Parameters

NOM_PWR Parameter description Correction factor to the open loop estimate


Value equates to: -3 – 3 dB

Discussion

The NOM_PWR is used to offset the computed open loop estimate if known imbalances of the Forward and Reverse links exist. While the value is used for all open loop corrections, it is the only correction used in Traffic Channel setup after a hard handoff to a new CDMA channel.

INIT_PWR Parameter description Correction factor to the open loop estimate for access probes


Value equates to: -3 – 3 dB

Section 10-10

Notes


10-10





Forward Closed Loop Power Control Parameters

PWR_REP_THRESH

Parameter description Number of frame errors to occur before the mobile reports these errors in a Power Measurement Report message

Included in: System Parameters message, Power Control Parameters message Recommended value 2

Value equates to: 2 frame errors

PWR_REP_FRAMES

Parameter description Number of frames over which the mobile is to compute frame errors, or duration of periodic reporting interval

Included in: System Parameters message, Power Control Parameters message Recommended value 13 – 15

Value equates to: 452 – 905 frames

PWR_THRESH_ENABLE Parameter description Controls whether threshold-based reporting is enabled



Section 10-11

Notes


10-11





Forward Closed Loop Power Control Parameters (continued)

PWR_PERIOD_ENABLE Parameter description Controls whether periodic reporting is enabled


Value equates to: Off

PWR_REP_DELAY

Parameter description Controls a delay in units of frames between a Power Measurement Report message being sent and the counting or frames and error frames restarting

Included in: System Parameters message, Power Control Parameters message Recommended value 1 – 2

Value equates to: 4 – 8 frames

FPC_MODE Parameter description Controls how the 800 bits/sec Forward Power Control bits are utilized

Included in: Power Control message, Non Negotiable Service Configuration, Extended Supplemental Channel Assignment message

Recommended value 0, 1, or 2

Value equates to: The value 0 is used when there is no FWD SCH assigned: all 800 bits are dedicated to FCH power control. When FWD SCH is assigned, the value 1 (400/400 bits split) or 2 (200/600 bits split) should be used.

Section 10-12

Notes


10-12






FPC_FCH_INIT_SETPT Parameter description Controls the initial value used by the mobile for FCH setpoint

Included in: Extended Channel Assignment message Recommended value 24 – 40

Value equates to: 3 – 5 dB

FPC_DCCH_INIT_SETPT Parameter description Controls the initial value used by the mobile for DCCH setpoint

Included in: Extended Channel Assignment message Recommended value 24 – 40


Section 10-13

Notes


10-13






FPC_SCH_INIT_SETPT_OP and FPC_SCH_INIT_SETPT Parameter description Controls the initial value used by the mobile for SCH setpoint

Included in: Extended Supplemental Channel Assignment message Recommended value 0, 24 – 40

Value equates to: Absolute setpoint mode, 3 – 5 dB Recommended value 1, 248 - 8

Value equates to: Relative to current FCH/DCCH setpoint, -1 to 1 dB

Section 10-14

Notes


10-14






FPC_FCH_MIN_SETPT

Parameter description Controls the minimal value the outer loop control in the mobile uses for FCH setpoint

Included in: Extended Channel Assignment message, Power Control message Recommended value 8 – 24


FPC_DCCH_MIN_SETPT

Parameter description Controls the minimal value the outer loop control in the mobile uses for DCCH setpoint



FPC_SCH_MIN_SETPT

Parameter description Controls the minimal value the outer loop control in the mobile uses for SCH setpoint

Included in: Extended Supplemental Channel Assignment message, Power Control message Recommended value 8 – 24


Section 10-15

Notes


10-15






FPC_FCH_MAX_SETPT

Parameter description Controls the maximum value the outer loop control in the mobile uses for FCH setpoint



FPC_DCCH_MAX_SETPT

Parameter description Controls the maximum value the outer loop control in the mobile uses for DCCH setpoint



FPC_SCH_MAX_SETPT

Parameter description Controls the maximum value the outer loop control in the mobile uses for SCH setpoint

Included in: Extended Supplemental Channel Assignment message, Power Control message Recommended value 56 – 80


Section 10-16

Notes


10-16






FPC_FCH_FER Parameter description Controls the target FER to be used by the mobile outer loop control for FCH

Included in: Extended Channel Assignment message, Power Control Message Recommended value 2

Value equates to: 1 % FER

FPC_DCCH_FER Parameter description Controls the target FER to be used by the mobile outer loop control for DCCH

Included in: Extended Channel Assignment message, Power Control message Recommended value 2


FPC_SCH_FER Parameter description Controls the target FER to be used by the mobile outer loop control for SCH

Included in: Extended Supplemental Channel Assignment message, Power Control message Recommended value 10


Section 10-17

Notes


10-17





Reverse Closed Loop Power Control Parameters

RLGAIN_TRAFFIC_PILOT

Parameter description Controls an additional offset of the Reverse link Traffic Channel’s power relative to the Reverse link Pilot power

Included in: Extended System Parameters message, General Handoff Direction message, Universal Handoff Direction message

Recommended value 0 Value equates to: 0 dB

RLGAIN_SCH_PILOT

Parameter description Controls an additional offset of the Reverse link SCH power relative to the Reverse link Pilot power


Recommended value 0 Value equates to: 0 dB

Section 10-18

Notes


10-18





Reverse Closed Loop Power Control Parameters (continued)

REV_PWR_CNTL_DELAY

Parameter description Informs the mobile of the delay from the power control group being measured to the power control group containing the matching power control bit for gated transmission


Recommended value 0 – 1 Value equates to: 1 – 2 PCGs

REV_FCH_GATING_MODE

Parameter description Controls whether Reverse link gating of 1/8 rate frames is allowed

Included in: Extended Channel Assignment message, General Handoff Direction message, Universal Handoff Direction message

Recommended value 1 Value equates to: On

PWR_CNTL_STEP

Parameter description Controls the change to Reverse link power for a single power control bit

Included in: Power Control message, General Handoff Direction message, Universal Handoff Direction message

Recommended value 1 Value equates to: 0.5 dB

Section 10-19

Notes


10-19





Soft Handoff Parameters

T_ADD

Parameter description Pilot power threshold controlling transition from Neighbor/Remaining Set Pilot to Candidate Set

Included in: System Parameters message, In-Traffic System Parameters message, Extended Handoff Direction message, General Handoff Direction message, Universal Handoff Direction message

Recommended value 24 – 28 Value equates to: -12 – -14 dB Ec/Io

T_DROP Parameter description Pilot power threshold controlling transition from Active Set


Recommended value 28 – 32 Value equates to: -14 – -16 dB Ec/Io

Discussion The T_DROP value is typically set at 2 dB below the T_ADD value.

Section 10-20

Notes


10-20





Soft Handoff Parameters (continued)

T_TDROP

Parameter description A timer value controlling how long a Pilot’s power must be below T_DROP before a PSMM message is generated


Recommended value 2, 3 Value equates to: 2 or 4 sec

T_COMP

Parameter description Relative Pilot power threshold of two Active Set Pilots before a PSMM report is generated



Section 10-21

Notes


10-21






SOFT_SLOPE

Parameter description A slope of a linear formula computing a dynamic value of T_ADD and T_DROP, depending on combined power of current Active Set

Included in: Extended System Parameters message, In-Traffic System Parameters message, Extended Handoff Direction message, General Handoff Direction message, Universal Handoff Direction message


ADD_INTERCEPT

Parameter description An intercept of the dynamically computed T_ADD threshold with Y axis at combined Active Set Pilot power of 0 dB



Click here for dynamic T_ADD/T_DROP computation example

Section 10-22

Notes


10-22






DROP_INTERCEPT

Parameter description An intercept of the dynamically computed T_DROP threshold, with Y axis at combined Active Set Pilot power stronger than Pilot being evaluated power of 0 dB



Section 10-23

Notes


10-23





Mobile Searching Parameters

SRCH_WIN_A Parameter description Search window size for searches of Active Set Pilots


Recommended value 6, 7, 8, 9 Value equates to: 28, 40, 60, 80 chips

SRCH_WIN_N Parameter description Search window size for searches of Neighbor Set Pilots


Recommended value 8, 9, 10, 11 Value equates to: 60, 80, 100, 130 chips

Discussion

The value of Neighbor Set search windows is usually higher than SRCH_WIN_A, due to the fact that the Neighbor Set search window is centered on the mobile system time, while the Active Set search windows are centered on the earliest arriving multipath for the Pilot, so the spread is smaller for Active Set searches.

Section 10-24

Notes


10-24





Mobile Searching Parameters (continued)

SRCH_WIN_R Parameter description Search window size for searches of Remaining Set Pilots


Recommended value 0, 8, 9, 10, 11 Value equates to: 4, 60, 80, 100, 130 chips

Discussion

The recommended value depends on whether the CDMA system performs logging of strong Remaining Set searches to provide data for Neighbor List management based on infrastructure logging; if not, the value 0 can be used, resulting in a very small search window size of 4, for a small overall increase in searching performance.

Section 10-25

Notes


10-25



Comments/Notes


10-26

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