80-W1527-2 Rev.C CDMA2000 1x and 1xEV-DO Network Planning

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Student Guide

Book 2

80-W1527-2 Rev C



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CDMA2000 1X and 1xEV-DO Network Planning

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v

Table of Contents – Book 2

Section 8: Traffic and Capacity .................................................................... 8-1

Section Learning Objectives ................................................................................ 8-2

General Traffic EngineeringTraffic Terminology ................................................................................ 8-3

System Definitions ................................................................................. 8-4

Metrics .................................................................................................. 8-5

Terminology ........................................................................................... 8-6

Erlang Theory ......................................................................................... 8-7

Characterization ..................................................................................... 8-8

Load .................................................................................................. 8-9

Erlang Theory ....................................................................................... 8-10

Erlang-B Formula ............................................................................................... 8-11

Erlang-B Table ................................................................................................ 8-12

General Traffic Engineering

Graphical Representation of Erlang Concepts ..................................... 8-13

Offered versus Carried ......................................................................... 8-14

Erlang-C Formula .................................................................................. 8-15

PS Data ................................................................................................ 8-16

PS Traffic Parameters ........................................................................................ 8-17

Packet Size and Packet Occurrence Probability ................................................ 8-18

PS Data Traffic Model........................................................................................ 8-19

M/M/1 Queuing Theory .................................................................................... 8-20

M/M/1 Queue ................................................................................................ 8-21

Latency Defined ................................................................................................ 8-22

M/M/1 Queuing Theory – Definitions .............................................................. 8-23

Latency and Total Delay .................................................................................... 8-25

Forward Link Capacity Estimation – Example ................................................... 8-26

Impact of Latency Requirement ........................................................................ 8-27

Impact of Page Size ........................................................................................... 8-28

General Traffic Engineering – Multi-Erlang Concepts ....................................... 8-29

Traffic Engineering – Multi-Service ................................................................... 8-30

Case Study ................................................................................................ 8-31

Multi-Erlang ................................................................................................ 8-32

General Traffic Engineering – CDMA and Traffic Engineering .......................... 8-33

CDMA Impacts on Traffic Engineering .............................................................. 8-34Resource Utilization in CDMA Networks .......................................................... 8-35

BTS ................................................................................................ 8-36

Hard Blocking Resources ...................................................................... 8-37

Impact of Soft and Softer Handoff on Resource Utilization ............................. 8-38

Multi-Erlang and M/M/1 ................................................................................... 8-39

Traffic and Capacity – What Did We Learn? ..................................................... 8-40

Section 9: Capacity and Dimensioning ......................................................... 9-1

Section Learning Objectives ................................................................................ 9-2




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vi

CDMA2000 RL Capacity ....................................................................................... 9-3

Reverse Link CDMA Capacity ............................................................................. 9-4

Fundamentals ........................................................................................ 9-5

Mobile Signal Power at BTS ................................................................... 9-6

Theoretical UL Capacity for Voice Only ............................................................... 9-7Eb/Nt Sensitivity .................................................................................................. 9-8

Impact of Network Planning on Alpha (Interference Factor) ............................. 9-9

CDMA2000 FL Capacity ..................................................................................... 9-10

Forward Link Capacity Calculation .................................................................... 9-11

1xEV-DO FL Capacity ......................................................................................... 9-12

Best Effort, Full Buffer ....................................................................................... 9-13

Maximum Theoretical Sector Throughput ........................................................ 9-14

Maximum Theoretical Throughput Considering Overhead .............................. 9-15

Practical Sector Throughput (Best Effort, Full Buffer) ...................................... 9-16

C/I Distribution of a Grid Network .................................................................... 9-18

Practical Sector Throughput (Best Effort, Non -full Buffer) ............................... 9-19

Equivalent Throughput Consumed by HTTP Users ........................................... 9-20

1xEV-DO RL Capacity ......................................................................................... 9-21

Reverse Link Capacity ........................................................................................ 9-22

Typical Values for Reverse Link Capacity Estimat ion ........................................ 9-23

VoIP (or VT) Sector Throughput ........................................................................ 9-24

EV-DO Capacity Summary ................................................................................. 9-25

Rev A Single Service Capacity – Summary......................................................... 9-26

Rel 0 Single Service Capacity – Summary .......................................................... 9-27

Capacity Numbers Used for Dimensioning ....................................................... 9-28

PS Data Applications and Dimensioning ........................................................... 9-29PS Data Call Model ............................................................................................ 9-30

PS Data Considerations ..................................................................................... 9-31

Packet Size and Packet Occurrence Probability ................................................ 9-32

Applications Considered for PS Data Call Model .............................................. 9-33

Application Summary ........................................................................................ 9-34

Dimensioning ................................................................................................ 9-35

Goals ................................................................................................ 9-36

Dimensioning ................................................................................................ 9-37

Rev A

Reverse Link, VoIP and B E .................................................................... 9-38

Forward Link, Multi-service (VT and BE) .............................................. 9-39Rev A Gain over Rel 0 Users .............................................................................. 9-40

Forward Link, Mixed Mode: Rel 0 and Rev A .................................................... 9-41

Multi-service Dimensioning .............................................................................. 9-42

Reverse Link ......................................................................................... 9-43

Capacity ................................................................................................ 9-44

Example ................................................................................................ 9-45

Example: Reverse Link, Multi -service Tradeoff ................................... 9-46

Exercises ................................................................................................ 9-47

1X Dimensioning ............................................................................................... 9-48




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1X Example ................................................................................................ 9-50

Voice versus Data Throughput .......................................................................... 9-51

Reference Material ........................................................................................... 9-52

DRC Mapping Table Example (Rel 0) ................................................................. 9-53

DRC Mapping Table Example (Rev A) ................................................................ 9-541xEV-DO Reverse Link Payload Size .................................................................. 9-55

Forward Link and Reverse Link – Application Payload Size .............................. 9-56

Capacity and Dimensioning – What Did We Learn? ......................................... 9-57

Section 10: Tools Overview ....................................................................... 10-1

Section Learning Objectives .............................................................................. 10-2

Basics ................................................................................................ 10-3

Network Planning Tools .................................................................................... 10-4

Bins ................................................................................................ 10-5

Network Planning Tools

General Features .................................................................................. 10-7

CDMA2000 Features ............................................................................ 10-9

3G Simulation Approaches .............................................................................. 10-11

Monte Carlo Simulation .................................................................................. 10-12

Network Planning Tools – Monte Carlo Simulation ........................................ 10-14

Tool Considerations

Selection Criteria: Compatibility ........................................................ 10-15

Additional Selection Criteria .............................................................. 10-16

Automatic Cell Planning Tools ........................................................................ 10-17

Basic ACP Concepts ......................................................................................... 10-18

How Can ACP Help? ........................................................................................ 10-21ACP Recommendations ................................................................................... 10-22

ACP Tool

Histograms ......................................................................................... 10-23

Plots .............................................................................................. 10-24

Network Planning Tool Usage ......................................................................... 10-25

Monte Carlo Simulation

User Distribution ................................................................................ 10-26

Reasons for Failures ........................................................................... 10-27

Increasing Coverage ........................................................................................ 10-29

Reducing Interference ..................................................................................... 10-30

CDMA Prediction Plots and Displayed Parameters ......................................... 10-31Debugging .......................................................................................... 10-32

CDMA Prediction Plots and Displayed Parameters –

Advanced Evaluation .......................................................................... 10-33

Simulation Reports .......................................................................................... 10-34

Global and Site Level .......................................................................... 10-35

Mobile Level Analysis ......................................................................... 10-36

Tools Overview – What Did We Learn? .......................................................... 10-37




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Section 11: Layer 1 and Other Parameters ................................ ....... 11-1

Section Learning Objectives ................................ ................................ .. 11-2Handoff (HO) and Network Planning ................................ .................... 11-3

Types of CDMA Handoffs – Overview ................................ ................. 11-4CDMA Soft Handoffs

– Soft Handoff Flow ................................ .......... 11-5

CDMA Handoff Parameters ................................ ................................ .. 11-6T_ADD ................................ ................................ ...................... 11-7T_DROP ................................ ................................ .................... 11-8

SRCH_WIN_(A,N,R) ................................ ................................ 11-9HO Parameters and Network Planning ................................ ................ 11-10

Plotting Handoff Status on a Map ................................ ........................ 11-11HO Optimization During Network Planning ................................ ....... 11-12Optimizing Soft Handoff ................................ ................................ ..... 11-13

Soft Handoff / Power Tradeoff ................................ ................ 11-14

Soft Handoff Increases RL Capacity ................................ ....... 11-15Statistics ................................ ................................ ................... 11-16

Basic HO Optimization Steps ................................ .............................. 11-17Handoff Optimization Example ................................ ........................... 11-18

Handoff Parameters Optimization ................................ ....................... 11-19Hard Handoff (HHO) ................................ ................................ ........... 11-21

CDMA Hard Handoffs ................................ ................................ ........ 11-22Triggers ................................ ................................ .................... 11-23CDMA Pilot Beacon ................................ ................................ 11-24

Hard Handoff with Pilot Beacons ................................ ............ 11-25Hard Handoff Types ................................ ................................ ............ 11-26

Major Points ................................ ................................ ............. 11-27HHO Ec/I0 Thresholds ................................ ................................ ......... 11-29

HHO Zone Allocation ................................ ................................ .......... 11-30Hard Handoff Planning – NL Planning ................................ ............... 11-31PN Offset ................................ ................................ ...................... 11-32

What is PN Planning? ................................ ................................ .......... 11-33PILOT_INC Parameter ................................ ................................ ........ 11-34

Pilot PN OffsetAssignment ................................ ................................ .............. 11-35Planning ................................ ................................ ................... 11-36

PILOT_INC Parameter ................................ ............................ 11-37PN Offset Conflicts – Aliasing ................................ ............................ 11-38

PN Planning AnalysisConstraints ................................ ................................ ............... 11-39Recommended PILOT_INC ................................ .................... 11-40

Example PN Offset Reuse ................................ ....................... 11-41Pilot PN Offset Assignment Plan ................................ ............. 11-42

Neighbor List Planning ................................ ................................ ........ 11-43Generic Considerations ................................ ............................ 11-44

Tool Limitations................................ ................................ ....... 11-45Using the Neighbor List ................................ ........................... 11-46




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Area Planning .............................................................................................. 11-47

Paging/BSC Planning – Paging Zones .............................................................. 11-48

BSC Planning – Base Station Controller Boundaries ....................................... 11-49

SID/NID/BSC Planning

Common Considerations .................................................................... 11-50Tool Limitations .................................................................................. 11-51

Layer 1 and Other Parameters – What Did We Learn? ................................... 11-52

Section 12: Practical Considerations for Network Planning ......................... 12-1


Antenna and Antenna Near Parts ..................................................................... 12-3

Near Parts ............................................................................................ 12-4

Antenna ................................................................................................ 12-5

Antenna Radiation Pattern .................................................................. 12-6

Surge Protectors/Lightning Arrestors .................................................. 12-7

Tails or Jumpers ................................................................................... 12-8

Diplexer ................................................................................................ 12-9

Feeder .............................................................................................. 12-10

Low Noise Amplifiers ......................................................................... 12-11

LNA Noise Factor Calculation ............................................................. 12-12

Summary ............................................................................................ 12-13

Main Antenna Characteristics – Radiation Patterns ....................................... 12-14

Antenna Selection

Based on Coverage Morphology ........................................................ 12-15

Based on Electrical Requirements ..................................................... 12-16

Based on Mechanical Requirements ................................................. 12-18Antenna Downtilt ............................................................................................ 12-19

Optimum Downtilt .......................................................................................... 12-20

Observations ...................................................................................... 12-21

Antenna Downtilt

EDT: Narrow Beam ............................................................................ 12-22

EDT: Large Beam ................................................................................ 12-23

MDT Pros and Cons ......................................................................................... 12-25

EDT Pros and Cons .......................................................................................... 12-26

Site Selection .............................................................................................. 12-27

Site Survey Checklist .......................................................................... 12-28

Pre-Qualified Site Database ............................................................... 12-29Zoning Analysis ................................................................................... 12-30

Search Rings ....................................................................................... 12-31

Site Off-Grid ....................................................................................... 12-32

Height Difference ............................................................................... 12-33

Site Off-Grid and Height Difference ................................................... 12-34

Understanding Future Growth ........................................................... 12-35

Repeater Sites .................................................................................... 12-36

Repeater Site Details .......................................................................... 12-37




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Summary ............................................................................................ 12-38

Practical Considerations for Network Planning –

What Did We Learn? .......................................................................... 12-39

Section 13: Overlays .................................................................................. 13-1


How to Overlay EV-DO and 1X? ........................................................................ 13-3

Same Band Overlay ........................................................................................... 13-4

Adjacent Carrier Consideration ......................................................................... 13-7

Case 1 ................................................................................................ 13-8

Case 2 ................................................................................................ 13-9

How a Non-Optimized 1X System Affects an EV-DO System .......................... 13-10

Ec/I0 Plots ............................................................................................ 13-11

DRC Rate Plots .................................................................................... 13-12

Comparison Plots ............................................................................... 13-13

Voice Comparisons ............................................................................. 13-14

Different Band Overlays .................................................................................. 13-15

Different Frequency Bands ............................................................................. 13-16

Overlays – What Did We Learn? ..................................................................... 13-17

Section 14: Capacity Planning Considerations ............................................ 14-1


Capacity Planning Considerations – Introduction ............................................. 14-3

Initial Traffic Forecasting ................................................................................... 14-4

Initial Capacity Forecasting ............................................................................... 14-5

Capacity Planning ConsiderationsCapacity Design Parameters ................................................................ 14-6

Subscriber Distribution and Growth .................................................... 14-7

Typical Capacity Design ........................................................................ 14-8

Forecasting for Capacity Planning ........................................................ 14-9

System Monitoring .......................................................................................... 14-10

Capacity Planning Considerations

Network Statistics Monitored for 1xRTT............................................ 14-11

Network Statistics Monitored for EV-DO ........................................... 14-12

Increasing Capacity ......................................................................................... 14-13

Capacity Planning Considerations

CDMA Capacity................................................................................... 14-14Introduction ....................................................................................... 14-15

Uneven Traffic Distribution ................................................................ 14-17

Number of Carriers per Sector ........................................................... 14-18

Adding a Carrier ................................................................................. 14-19

Capacity Planning Considerations – What Did We Learn? .............................. 14-20




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Section 15: Course Summary ..................................................................... 15-1

Ec/Io Calculation – Single Cell ............................................................................ 15-2

Reverse Link Budget – Summary ....................................................................... 15-3

Forward Link Budget – Equality Coverage Comparison .................................... 15-4

CDMA Bands ................................................................................................ 15-5Hata Cell Radius Graph...................................................................................... 15-6

Resource Utilization in CDMA Networks .......................................................... 15-7

Multi-service Dimensioning – Reverse Link ...................................................... 15-8

Different Frequency Band ................................................................................. 15-9

Network Planning

Coverage ............................................................................................ 15-10

Capacity .............................................................................................. 15-11

RF .............................................................................................. 15-12

Network Planning Skills ................................................................................... 15-13




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Traffic profiles and traffic intensity:

Considering the traffic intensity formula, 10 calls of 100 seconds each would have the sameintensity as 100 calls of 10 seconds each; both cases would use the servers equally. Considering

calls from end-to-end, different call profiles can stress the system differently.

A typical example is BSC dimensioning, which needs to consider the total traffic intensity (how

many Erlangs can be carried), but also the call arrival rate (busy hour call attempts).




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Erlang-B Formula

The Erlang formula typically is not used directly. It is more commonly used to determine thenumber of resources needed to carry a traffic demand (offered traffic) based on acceptable Grade of

Service (1 – Blocking).

During network dimensioning, offered traffic is estimated based on previous network

measurements or marketing assumptions. The GoS is usually determined from marketing

assumptions.

The formula is used to draft an Erlang-B table showing offered traffic for different numbers of

resources and GoS targets. An example is presented on the next page.




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Blocking

Resources

0.01 0.02 0.03 0.04 0.05 0.1 0.2 0.3

1 0.01 0.02 0.03 0.04 0.05 0.11 0.25 0.43

2 0.15 0.22 0.28 0.33 0.38 0.60 1.00 1.45

3 0.46 0.60 0.72 0.81 0.90 1.27 1.93 2.63

4 0.87 1.09 1.26 1.40 1.52 2.05 2.95 3.89

5 1.36 1.66 1.88 2.06 2.22 2.88 4.01 5.19

6 1.91 2.28 2.54 2.76 2.96 3.76 5.11 6.51

7 2.50 2.94 3.25 3.51 3.74 4.67 6.23 7.86

8 3.13 3.63 3.99 4.28 4.54 5.60 7.37 9.21

9 3.78 4.34 4.75 5.08 5.37 6.55 8.52 10.58

10 4.46 5.08 5.53 5.90 6.22 7.51 9.68 11.95

11 5.16 5.84 6.33 6.73 7.08 8.49 10.86 13.33

12 5.88 6.61 7.14 7.57 7.95 9.47 12.04 14.72

13 6.61 7.40 7.97 8.43 8.83 10.47 13.22 16.11

14 7.35 8.20 8.80 9.30 9.73 11.47 14.41 17.50

15 8.11 9.01 9.65 10.17 10.63 12.48 15.61 18.90

16 8.88 9.83 10.51 11.06 11.54 13.50 16.81 20.30

17 9.65 10.66 11.37 11.95 12.46 14.52 18.01 21.70

18 10.44 11.49 12.24 12.85 13.39 15.55 19.22 23.10

19 11.23 12.33 13.11 13.76 14.31 16.58 20.42 24.51

20 12.03 13.18 14.00 14.67 15.25 17.61 21.64 25.92

21 12.84 14.04 14.89 15.58 16.19 18.65 22.85 27.33

22 13.65 14.90 15.78 16.50 17.13 19.69 24.06 28.73

23 14.47 15.76 16.68 17.42 18.08 20.74 25.28 30.15

24 15.29 16.63 17.58 18.35 19.03 21.78 26.50 31.56

25 16.12 17.50 18.48 19.28 19.99 22.83 27.72 32.97

26 16.96 18.38 19.39 20.22 20.94 23.88 28.94 34.38

27 17.80 19.26 20.31 21.16 21.90 24.94 30.16 35.80

28 18.64 20.15 21.22 22.10 22.87 25.99 31.39 37.21

29 19.49 21.04 22.14 23.04 23.83 27.05 32.61 38.63

30 20.34 21.93 23.06 23.99 24.80 28.11 33.84 40.05

31 21.19 22.83 23.99 24.94 25.77 29.17 35.07 41.46

32 22.05 23.72 24.91 25.89 26.75 30.24 36.30 42.88

33 22.91 24.63 25.84 26.84 27.72 31.30 37.52 44.30

34 23.77 25.53 26.78 27.80 28.70 32.37 38.75 45.72

35 24.64 26.43 27.71 28.76 29.68 33.43 39.98 47.14

36 25.51 27.34 28.65 29.72 30.66 34.50 41.22 48.56

37 26.38 28.25 29.59 30.68 31.64 35.57 42.45 49.98

38 27.25 29.17 30.53 31.64 32.62 36.64 43.68 51.40

39 28.13 30.08 31.47 32.61 33.61 37.71 44.91 52.82

40 29.01 31.00 32.41 33.57 34.60 38.79 46.15 54.24

41 29.89 31.92 33.36 34.54 35.58 39.86 47.38 55.66

42 30.77 32.84 34.30 35.51 36.57 40.94 48.62 57.08

43 31.66 33.76 35.25 36.48 37.56 42.01 49.85 58.50

44 32.54 34.68 36.20 37.46 38.56 43.09 51.09 59.92

45 33.43 35.61 37.16 38.43 39.55 44.17 52.32 61.35

46 34.32 36.53 38.11 39.40 40.54 45.24 53.56 62.77

47 35.21 37.46 39.06 40.38 41.54 46.32 54.80 64.19

48 36.11 38.39 40.02 41.36 42.54 47.40 56.03 65.61

49 37.00 39.32 40.97 42.34 43.53 48.48 57.27 67.04

50 37.90 40.26 41.93 43.32 44.53 49.56 58.51 68.46

60 46.95 49.64 51.57 53.16 54.57 60.40 70.90 82.70

70 56.11 59.13 61.29 63.08 64.67 71.29 83.32 96.95

80 65.36 68.69 71.08 73.06 74.82 82.20 95.75 111.21

90 74.68 78.31 80.91 83.09 85.01 93.15 108.19 125.47

100 84.06 87.97 90.79 93.15 95.24 104.11 120.64 139.73




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Offered and Served Traffic

The Erlang formula (or table) is used to estimate the offered traffic. The served traffic is lower thanthe offered traffic, and both are linked by the given formula. For large number of servers and high

blocking probability, the offered traffic can be larger than the number of servers (but the served

traffic will always be lower than the number of servers).




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Erlang-C Formula

This slide shows a simplified formula for Erlang-C; it is equivalent to the original formula:

1

0 !*)1(

!

!Pr n

i

n

T

n

n

in

n

T T

T




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PS Traffic Parameters

Session Duration

A session could last a few seconds or a few days. The definition of a session also depends on what needsto be dimensioned.

In terms of the actual occupancy of radio resources, the session should be defined as the period forwhich the end-user application is active (used) rather than the time the application is open.

If a session is defined as a dataflow between applications, several sessions could be open at the sametime on a given terminal.

Session Data Volume

For the entire session space, this is a random variable that could take any value from a few bits toseveral megabits.

The data volume per session is typically modeled as a Poisson distribution, with the average volume persession as the parameter.

– This does not fully account for the packet aspects of the service. To account for those, it necessaryto further divide the session into its basic blocks.

Number of Packet Calls per Session

The distinct period when data is exchanged among the distant terminals, typically separated by idleperiods (reading time).

Idle Time between Packet Call and Reading Time

The reading time affects code channel usage. Ideal systems would use no resources during reading time,because no data is exchanged.

In current systems, this is controlled mainly by dormancy timers.

Data Volume in a Packet Call

This variable can be expressed in terms of the number of packets (or datagrams) in a session and thepacket size.

Data volume and the data rate of the bearer affect capacity, delays, etc.




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Data packet call models

Different standard bodies use different packet call models. This shows that, unlike voice, PS data isnot a single application.

3rd Generation Partnership Program (3GPP)

This typically refers to the standardization body working on the UMTS/WCDMA protocols. The 3rd

Generation Partnership Program 2 (3GPP2) focuses on CDMA2000 and its evolution.




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PS Data Traffic Model

1 Based on weighted average of main and embedded object.2 Based on minimum size of the main and embedded objects.

3 Based on parsing time and number of objects.

4 Audio streaming assumed.

5 Object in this case corresponds to 1 frame (assuming 10 frames per second for video, and 50

frames for audio).

6 Assuming 180 second streaming.

M/M/1 model is described later in this section




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M/M/1 and Erlang Model Analogy

The Erlang model estimates the blocking probability for an average resource utilization. Similarly,M/M/1 models estimate the latency of data for an average loading (bearer efficiency).

M/M/1 Limitations

To overcome M/M/1 model limitations, alternative models (such as G/G/1 or G/M/1) can be used.

Although these models may be more accurate, they usually require look-up tables, which makes

them less convenient than the M/M/1 model for dimensioning.




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M/M/1 and latency

Although latency can occur in different parts of the network, the latency estimated by the M/M/1model is only for a single link at a time. In this section, only the latency from the BTS to the mobile is

estimated. Latency between other nodes would depend on their respective occupancy.




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M/M/1 Queuing Theory – Definitions

1 This rate can be derived from the monthly usage and any peak to average, or traffic profileinformation, divided by the number of cells in the network. The serving rate depends on

channel characteristics and the request size.

2 This delay measures only the time between a request from the user and when the download is

initiated; it does not include the time to complete the download. To estimate the total delay,

add the download (or data transfer) time, which is controlled mainly by the assigned channel

used for communication and the radio conditions.

3 This corresponds to the aggregate throughput of all users performing FTP, or similar

downloads.




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Notes




8-25


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Efficiency

Efficiency ( ) can also be calculated as:

=(T* -1)/(T* )




8-26


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Forward Link Capacity Estimation – Example

1 Knowing the total number of requests to serve for all users of all cells, and the average arrivalrate per cell, we can easily calculate the number of cells.




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Notes




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Notes




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Notes




8-30


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Traffic Engineering – Multi-Service

[Answers are provided at the end of this section.]




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Case Study





8-32


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Multi-Erlang

To determine the offered traffic when resources are shared between services, a few assumptionsmust be made.

For two services (Service 1 and Service 2 in the figure), a fixed resource utilization between servicesshould exist. In the graph, Service 1 is assumed to consume 1 resource, while Service 2 consumes 4resources. With this resource consumption, and with 40 resources available, 40 trunks could bedefined for Service 1 and 10 trunks for Service 2.

Resources can be shared linearly between the services. When only Service 1 is required, all 40resources can be dedicated to this service (40 trunks); when only Service 2 is required, all 40resources can be dedicated to that service (10 trunks). If the resources were shared equally (20 toService 1 and 20 to Service 2), the number of trunks available for each service would be directlydependent on the resource utilization (20 trunks for Service 1, 5 trunks for Service 2).

The offered traffic for each service can be determined using an Erlang-B formula, according to thenumber of trunks available and the expected GoS for each service. Using the previous example ofsharing the resources equally, with 20 trunks available for Service 1, 13.2 Erlangs would be offered,while 1.66 Erlangs would be offered for Service 2.

To determine the overall offered traffic, one must determine the operating point, i.e., the point thatcorresponds to the ratio of traffic demand. As an example, if the total demand for Service 1 is 100Erlangs and for Service 2 is 20 Erlangs, the operating point would be where the ratio of offeredtraffic for Service 1 and Service 2 is the closest to 0.2. On the above figure, this falls between (13.2,1.66) and (9.83, 2.28).




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Notes




8-34


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Traffic – CDMA Specifics

Blocking occurs for different reasons in a CDMA system. Interference is the most common cause ofblocking. However, in a real network, this is not what is directly observed.

On the Forward link, limited available power is an apparent reason for soft blocking. However, the

real cause of the blocking might be interference, because power is used to overcome interference

(yet itself generates interference to other users). To determine the actual cause, consider both total

transmit power and the number of users served.

Hard blocking can also occur on a CDMA system. Traffic Channel Elements (TCE) and channelization

codes (Walsh Codes) are potential sources of hard blocking. TCE blocking, in contrast to soft

blocking, is easy and cheap to manage: simply add hardware to the cell.




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Notes




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Notes




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Channel Elements and Erlang Theory

When a single service is used, Erlang theory can be used directly for CE dimensioning.

When multiple services are used, multi-Erlang dimensioning is necessary. Alternatively, simulations

can be done to dimension CE based on a given call model.




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Impact of Soft and Softer Handoff on Resource Utilization

Sf_HORF–

Softer Handoff Reduction Factor HORF – Handoff Reduction Factor




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Notes




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Notes




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Comments/Notes




9-1

Section 9: Capacity and Dimensioning

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Notes




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Notes




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Notes




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Notes




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Notes




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Notes




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Reverse Link Capacity Equation

Typical values for:

: 0.5 for voice. For PS data, 1 can be used.

α: 0.65 for a three-cell site.

– α in this equation is related to the Frequency reuse factor (c.f. slide 9). The interference

factor takes into account the mobiles in other cells not power controlled by the

considered cell.

The calculated capacity values will be affected by:

Demodulator implementation, because the required Eb/Nt will change.

Propagation environment, because the required Eb/Nt will change. Site selection and optimization, because α will change.




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Eb/Nt Sensitivity

Eb/Nt is affected by the RF propagation conditions (multipath), the speed of the MS, and theoperating frequency band. Details of the Eb/Nt requirement are specified in C.P0010-C-1. The

following table summarizes data for the main test case, main frequency bands, 2% FER.

Eb/Nt

Case / Frequency Band 800 MHz 1900 MHz 450 MHz

Case A 3.47 3.8 3.3

Case B 3.9 4.55 3.85

Case C 5 5.2 4.6

Case D 4.7 5 4.75




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Optimization and Parameters Impact on F (and α)

F is directly affected by the mobiles that are detected in a given sector but are not power controlledby that sector. When a mobile is power controlled by the sector, it would reach the sector no higher

power than other mobiles, because of the Or-of-the-downpower control implementation. When the

mobile is not power controlled by a given sector, it may be detected at the sector at a higher power

than other mobiles, thus increasing the RoT, while decreasing the capacity.

By extension, the same variable that affects the handoff also affects the RL capacity:

Optimization– Decreases cell overlap which decreases the number of mobiles detected by a

cell.

Handoff parameters – Controls mobiles in the Active Set, which are power controlled by the

sector.The BPL also affects the Frequency Reuse Factor. To achieve a higher BPL, cells must be placed

closer to each other, which makes it more difficult to control their coverage.




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Notes




9-11


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Test Condition

Test condition refers to standard tests defined to determine the minimum performance of a mobilestation (described in the standard C.S0011-C, V2.0). Each test is defined for mobile speed, radio

environment (multi-path), and geometry, as described below:

Test 2: 3 km/h, 1 path, Ior/Ioc = 6 dB

Test 4: 30 km/h, 1 path, Ior/Ioc = 4 dB

Test 6: 100 km/h, 3 paths, Ior/Ioc = 2 dB




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Notes




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Notes




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Notes




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Maximum Theoretical Throughput Considering Overhead

At higher layers, additional overhead must be considered. For example, with a VoIP application with176 bits of user data (8800 user throughput), up to 80 bits of overhead (RoHC, checksum, RLP

header, stream layer, MAC, FCS, etc.) are inserted to form a 256-bit packet.

Each application has a different overhead requirement. Overhead also depends on the transmission

protocol. For example, the following can be calculated:

Max TCP segment: 1500 bytes (12000 bits) 1500

IP overhead: 20 bytes (160 bits) 1520

TCP overhead: 20 bytes (192 bits) 1540

(TCP overhead can contain an optional 4 bytes)

UDP overhead: 8 bytes (64 bits).

Either TPC or UDP framing would be used, not both.

RLP packet size: 128 bytes (1024 bits) 12 * 128

RLP overhead: 6 bytes (48 bits) 12 * 134

Total bytes 1608

Total overhead 7.2%




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Notes




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Notes




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Notes




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Notes




9-20


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FTP and HTTP Traffic Mix

From field experiments, the available FTP throughput was measured for different numbers of HTTPusers. From the results, we can observe that the achievable FTP throughput decreases as the

number of HTTP users increases. From this, we can estimate an FTP equivalent throughput for each

HTTP user.




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Notes




9-22


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Reverse Link Capacity

A typical capacity equation for the Reverse link is based on an approximation that assumes that Npole

is much larger than 1.

For a high data rate bearer, this assumption does not hold true, resulting in an underestimation of

the cell capacity.




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Notes




9-24


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VoIP (or VT) Sector Throughput

According to the capacity equation, the estimated VoIP capacity would be achieved for Eb/Nt of 6.5to 7, while the typical Eb/Nt for 9600 kbps data (16 slots termination) is in the range of 3.25 (Rev A)

to 6.25 (Rel 0). In section 4, for EvDO, rather than Eb/Nt , the traffic Ec/Nt is given. The conversion

can be done when considering the data rate and the spreading rate:

ratedata

rate spreading Log

N E

TrafficdB N

E

t

c

t

b

_

_ .10][




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Notes




9-26


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Rev A Single Service Capacity – Summary

Unless mentioned otherwise:

FL assumes receive diversity implemented at the AT.

RL assumes 2-way receive diversity implemented at the AN.

No equalizer, PIC, or TIC (multi-user detection) at either AT or AN.




9-27


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References

[1] Rashid Attar and Naga Bhushan, CDMA2000 1xEV-DO Concepts (Qualcomm document number80-H3343-1, Rev. A).

[2] Lower boundary accounts for typical RF limitation observed in deployed networks.




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Notes




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Notes




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Notes




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Notes




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9-40


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Rev A Gain over Rel 0 Users

1 Average is weighted according to recommended 3GPP2 (C.R1002-0 v1.0) distribution.




9-41


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Forward Link, Mixed Mode: Rel 0 and Rev A

Tradeoff is based on simulation. Same RF conditions are used, all Rev A DRC available forRev A users; only Rel 0 DRC available for Rel 0 users. DRC mapping representative of receiver

implementation.




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Multi-service Dimensioning

The FL/RL data volume ratio depends on the application. To understand the typical ratio in anetwork, look at the individual application characteristics and the traffic mix.

Typical examples of FL/RL ratio for selected applications are:

Gaming: 60%

Mobile Office: 45%

Web browsing: 13%

PDA sync: 15%

Download: 10%

Upload: x10

Streaming: 3%




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Notes




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Exercises





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Notes




9-50


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1X Example

The minimum performance for voice considers fundamental channel; supplemental channels areconsidered for data.

All minimum performance values are based on C.S0011-C v2.0, thus are representative of FL

capacity.

In this example:

Voice activity factor for voice is assumed to be 0.5

Data activity factor is assumed to be 1

Overhead represents 20% of total power.




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Notes




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Notes




9-53


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DRC Mapping Table Example (Rel 0)

SINR thresholds are AT implementation dependent. The SINR thresholds given in this examplecould be considered typical of a single antenna and rake implementation. This is a typical

implementation for a commercially available Rel 0 AT.




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DRC Mapping Table Example (Rev A)

SINR thresholds are AT implementation dependent. The SINR thresholds given in this examplecould be considered typical of a dual antenna (receive diversity) and equalizer implementation. This

is a typical implementation for a commercially available Rev A AT.




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Notes




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Forward Link and Reverse Link – Application Payload Size

1xEV-DO Rev A header length (and trailer length where applicable):

RLP 22 bits (other options 14 bits or 6 bits)

Stream 2 bits

Connection 8 bits (if Format B packet does not have enough bits to fill a Connection

Layer packet)

Security Layer Depends on security features, but probably 0

MAC Layer 2 bits trailer

Physical Layer 30 bits (24 bits CRC and 6 bits of tail)




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Notes




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Comments/Notes




10-1

Section 10: Tools Overview

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Notes




10-2


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Notes




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Notes




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Notes




10-5


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Bins

The bin size should match map data accuracy. Bin sizes much smaller than the map resolutionare not helpful for network planning, and increase the size of the prediction file without

increasing accuracy. Alternatively, if the bin size is much larger than the map resolution, map

accuracy is lost.




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Bins and Calculation

For each sector, path loss is calculated over a binned area. The calculation area is bounded by acell radius, which is usually configurable. In each bin, the path loss to neighboring sectors is

assumed constant over the area of the bin.

When predicting coverage or performing simulations, multiple servers are considered at each

bin. For accurate interference calculations, consider a minimum of 20 servers, which improves

the accuracy only for areas without a dominant server.

The volume of data to be generated is another important consideration.

For each bin, a user-selectable number of path loss values from specific cells is calculated. A

variable bin size enables high resolution in areas of interest, and low resolution outside thoseareas.

Site-to-site distance is also important. With a very dense network and a large bin, only a few bins

could separate sites, which would not provide sufficient accuracy for the prediction.




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GIS Features

Cartographic database supporting: – Digital elevation models

– Clutter data (type and height)

– 3-D building data

– Traffic data

– Scanned maps

– Vector data

– Population data

Integrated cartography editor (vector/raster)

Interface with commercial GIS tools: MapInfo, ArcView, etc.

User and Database Management

Flexible database structure allowing integration of user-defined parameters.

Multi-user support including database consistency management, data synchronization, anduser disconnection/reconnection from/to the database.

Administration module supporting data access and user privilege management.

Support for standalone, centralized, and distributed configurations.

Import/export features allowing quick data migration from other RF planning tools.




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Distributed Computing

Distributed computing on networked workstations Parallel computing on dual-processor systems

Printing and Reports

Report generator including traffic, population, and clutter-based statistics

Report generator for every prediction in defined area

User-defined reports based on macros

Export of reports and prediction plots into other software

Measurement Module

CW measurements

–

Import, display, and analysis of CW data – Prediction/measurements comparison and statistical analysis

– Automatic propagation model tuning using CW measurements

Test mobile/Scanner data

– Import, display, and analysis of test mobile data (automatic preferred)

– Graphical replay on map combined with user-defined graphs

– Call events display and analysis

– Data filtering

– Sorting by PN

– Automatic propagation model tuning using test mobile data




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Network and Radio Parameter Modeling

Network database

Support for Repeaters

Radio configuration and channel modeling

Radio resource modeling

Support for multiple carriers and frequency bands

Carrier type modeling (1xEV-DO and 1xRTT)

FCH and SCH modeling

Additional radio configurations (RC3, RC4, RC5)

Data Services Modeling

FCH activity factor/SCH variable rate modeling

SCH and FCH Forward and Reverse link E b/Nt thresholds

1xEV-DO Rel. 0 and Rev. A quality tables (C/I vs. Forward link data rate)

Reverse link 1xEV-DO Rel. 0 and Rev. A physical channels modeling

Rev.A bearer modeling

Traffic Modeling

Modeling of voice and data services and applications

Support for multiple sources of traffic data

– User distribution maps

– Live traffic data per service per cell

– Service demand maps (raster/vector)




10-10


80-W1527-2 Rev C


Multi-service Monte Carlo Simulation

Modeling of mixed 1xRTT/1xEV-DO traffic Forward link cell capacity calculation

SCH and FCH power control modeling

Reverse and Forward link SCH data rate downgrading (1xRTT)

Reverse link power control simulation including data rate downgrading (1xEV-DO)

Forward and Reverse link coverage per SCH rate (1xRTT)

Forward and Reverse link prediction plots per data rate (1xEV-DO)

Neighbor and PN-offset Planning

Manual and automatic neighbor planning

Multi-carrier neighbor planning

Automatic PN-offset allocation

PN-offset allocation analysis




10-11


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Analysis During the Network Planning Phases

Statistical analysis (coverage and Ec/I0) should be run initially to verify that the coverageobjectives are achieved without creating significant Forward link interference (unloaded case).

Lack of coverage should be addressed through coverage improvement techniques such as:

Adding a sector or site

Increasing the antenna gain

Reducing miscellaneous losses (feeder, jumper, etc.)

Increasing HPA power

When coverage and unloaded network objectives are met, run a Monte Carlo simulation to verify

network behavior under the anticipated load. In particular, verify that the network has sufficientsectors/sites to handle the traffic. This simulation helps to focus optimization efforts on the areas

that carry the most traffic.

Dynamic simulation improves the accuracy of the Monte Carlo simulation, especially for PS data

applications, but are not commonly used.




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Notes




10-13


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Monte Carlo Simulation

Several Monte Carlo iterations must be run to obtain results that have statistical validity.Depending on the number of users distributed, 20 to 50 iterations minimum should be run.




10-14


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Traffic Density

For simulations that use a Monte Carlo or similar statistical distribution analysis, two loops aredefined. The name of the loops can change from vendor to vendor, but they have the following

main purposes:

Trial or distribution – During each trial, users are distributed over the area, based on rules

set by the traffic maps, clutter weighting, call models, etc. After the users are distributed,

the tool tries to reach a stable state by performing iterations.

Iteration – During a trial, the iterations are similar to the power control process. The

power to (and from) each mobile is varied over fixed increments until a stable condition is

achieved, i.e. the convergence limit has been reached. If convergence cannot be reached,

the iteration stops when a preset number of iterations have run. The convergence limit can be path loss, SIR, Ec/I0, or RSCP, to name a few.




10-15


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Notes




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Notes




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Notes




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Notes




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Notes




10-20


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Costs and ACP

The term cost is used in two different way in an Automatic Cell Planning tool. For each of thechanges (degree of freedom), a financial cost can be associated. This cost is used by the tool to

prioritize the type of change, in order to minimize the total cost of an optimization task.

The term cost is also used in cost function. This refers to the quantification of the improvement

made during the optimization to verify if system performance has improved.




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Notes




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Notes




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Notes




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Notes




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Notes




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Monte Carlo Simulation Results

Different tool implementations will produce different results, but Monte Carlo results should beavailable in two forms: plots and statistics. Both forms should present the main cause of failures

to assist solving the issues.

The plots are mainly used to quickly identify areas with a high number of failures. Such areas

can be a priority for optimization.

For the statistical results, in addition to average values (such as failure rate) it is important to

have a representation of the distribution (e.g., standard deviation). With both average values and

standard deviation, margin can be estimated. Margins can be used to determine the number of

resources required (e.g., channel elements).




10-27


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Solving Failures

Low Pilot: This type of failure should be detected only in an area where coverage (Ec/I0) issueswere detected. This failure can indicate either low coverage or high interference. In an area

where low Pilot is detected, both the coverage (Ec) and the interference (Ec/Io) should be

observed.

Insufficient Mobile Power: This type of failure typically indicates high Reverse link

interference (low Pilot would otherwise be detected), or it could indicate unbalanced links. This

would be the case for high data rate because the required MS Tx power increases as a function of

the data rate, thus limiting the coverage for high data rate (coverage is discussed later in this

section).

Insufficient Channel Power: This type of failure indicates insufficient FL TCH power

assignment. FL power is consumed mostly by FL interference and, to a lesser extent, path loss.

To address insufficient channel power, first investigate FL interference (see coverage, discussed

later in this section), then increase the maximum power allocation for the failing data rate.

Maintain a balance between FL load saturation (exhaustion of HPA) and individual link failure

(Ptch > Ptchmax). An equal amount of failures between these two causes indicates a good trade-

off between coverage (Ptch > Ptchmax) and capacity (FL load saturation). Also consider data

rate: This type of failure for PS data service does not necessarily prevent service for the user; it

may only indicate that a lower data rate would be available at that location.




10-28


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Solving Failures (continued)

RL Noise Rise: May be due to the number of users, or excessive RL interference caused byunbalanced Forward and Reverse links. High RL interference can be created if the maximumActive Set size is set too low. In this case, the MS can be in the coverage of the sector, but notallowed to be in HO with the sector. As a result, the MS cannot be power controlled by thissector and may transmit at a higher power, causing excess RL interference.

Power Saturation: Indicates exhaustion of HPA resources. This could be caused by too manyusers in the cell, or the users require too much power. The latter case indicates FL interference.FL load saturation and coverage (Ptch > Ptchmax) need to be balanced.

Channel Element Saturation: Channel element consumption is implementation specific;therefore, CE settings for Monte Carlo simulation should correspond to the actual BTS used.

Monte Carlo simulation can be used to dimension a-posteriori the channel element for each site by converting the number of traffic channels to channel elements, as appropriate for equipmentvendor specifications. The Erlang B formula can be used to convert traffic (link or RB) intorequired resources. To prevent blocking due to channel element saturation, a low blocking rate(typically 0.1 to 0.5%) should be used.

Code Saturation: In the absence of FL load saturation, this would occur when inefficientapplications are predominant in the network, or if the channel conditions are abnormally good.Until Equalizer and Received diversity is widely deployed, power (FL saturation) is expected to be the main cause of blocking in the FL. Usage of RC4 can reduce code saturation, but typicallyat the expense of higher FL power used per link.




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Notes




10-30


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Reducing Sector Power

While it is theoretically possible to reduce the site overlap by changing the sector total power, itis not a recommended approach. The impact of such a change would negatively impact capacity

and link balance in ways that may not be evident when evaluating the change.




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CDMA Prediction Plots and Displayed Parameters

For an initial evaluation, all plots can be based on a static configuration.

1. Coverage (signal level) is first verification of system quality, because without coverage no

service can be achieved.

2. After Pilot coverage is confirmed, verify the quality of the configuration using Pilot

reception analysis. For an unloaded system, any area with an Ec/N0 lower than -9 dB should

be improved. This threshold corresponds to three equal overlapping sectors.

3. After coverage and interference are under control, verify if coverage of the sites is

contiguous without any major issues such as sector fragmentation, coverage imbalance

between adjacent sites, or sector overshooting.

4. Finally, estimate Pilot and Forward and Reverse link coverage over the effective service

area.




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Debugging

A second plot analysis identifies solutions to the problems indicated in the initial plot analysis.The Pilot pollution plot shows areas with a high number of potential (e.g., strong) servers.

Combine this plot with a spider cursor to see which servers are present and determine which

servers should be removed or reduced in the area.

If multiple area show issues, a more systematic (but longer) approach is to verify the coverage of

each individual server and control any server that is over-propagating (e.g., detected with a

strong level past the 2nd tier).




10-33


80-W1527-2 Rev C


Advanced Evaluation

After completing the initial evaluation and optimization of the system, run a Monte Carlosimulation. From this simulation, a secondary set of plots can be drawn to determine the

performance of the common channels and dedicated channels, both RL and FL.




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Notes




10-35


80-W1527-2 Rev C


Example of Statistics used During Analysis

Analysis of 1xRTT sectors

Total FL power, total FL FCH power, total FL SCH power, FL load factor, percentage of

power used, etc.

RL load factor, RL noise rise and reuse factor

Number of users connected on RL and FL

Number of Walsh codes used

RL and FL allocated throughput

Percentage of users in handoff

Analysis of 1xEV-DO sectors

Information related to RL mobile power (total noise, load factor, reuse factor, etc.)

Number of users connected on RL

RL and FL allocated throughput

Percentage of users in handoff




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Notes




10-37


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Notes




10-38


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Comments/Notes




11-1

Section 11: Layer 1 and Other Parameters

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Notes




11-2


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Notes




11-3


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Notes




11-4


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Types of CDMA Handoffs – Overview

CDMA supports mobile handoff from one cell to another while the mobile is on a Traffic Channel orin the Idle state.

The in-traffic transition from one cell to another can be either a soft handoff or a hard handoff .

Transition from one cell to another while in the Idle state must be a hard handoff.

Access handoff has multiple forms:

Access Entry handoff is an Idle handoff before the handoff process begins.

Access Probe handoff sends the Access probes to different sectors or different Base Stations.

Access handoff transfers the reception of the Paging Channel from one Base Station to

another while the mobile is in the System Access State, but after an Access Attempt.




11-5


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Soft Handoff Flow

1. Pilot strength exceeds T_ADD. The mobile sends a Pilot Strength Measurement message andtransfers Pilot to the Candidate Set.

2. The Base Station sends an Extended Handoff Direction message or General Handoff

Direction message.

3. The mobile transfers the Pilot to the Active Set and sends a Handoff Completion message.

4. Pilot strength drops below T_DROP. The mobile starts the handoff drop timer.

5. Handoff drop timer expires. The mobile sends a Pilot Strength Measurement message.

6. The Base Station sends an Extended Handoff Direction message or a General Handoff

Direction message.

7. The mobile moves the Pilot from the Active Set to the Neighbor Set and sends a HandoffCompletion message.




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Notes




11-7


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Notes




11-8


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Notes




11-9


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Additional Parameters

In addition to the main three HO parameters, additional HO parameters exist to control the timing ofthe HO (t_tdrop), provide additional reporting capabilities (t_comp), or help reduced the AS size

(soft-slope, ADD_INTERCEPT, DROP_INTERCEPT).

For additional details, sign up for CDMA University’s CDMA

Engineering Basics or CDMA2000 1X Protocols and Signaling .




11-10


80-W1527-2 Rev C


T_ADD and T_DROP Usage in Network Planning Tools

Not all network planning tools use the values for T_Add and T_Drop the same way. Some tools useT_Add to add a server to the Active Set (as it should be) but use T_Drop as the threshold to

determine that no servers are usable.

For these and all other network planning tool settings, it is critical to understand how the parameter

is used in the tool.

Soft/Softer DRC gain in Network Planning Tools

When implemented, this parameter helps compensate for the static nature of the network planning

tools. Without such implementation, in the soft and softer area, the predicted throughput is much

lower than typically measured in the field.




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Handoff and Monte Carlo Simulations

Network planning tools can estimate handoff statistics, based on Monte Carlo simulations. Inaddition, planning tools may provide plots that represent individual simulations. In the plot above,

the handoff status is displayed as “X/Y” where “Y” is the number of sectors to which the mobile is

connected and “X” is the number of sites. For example, “2/3” means that a particular mobile is

connected to three different sectors on two sites.

In addition to Monte Carlo-based plots and statistics, network planning tools can provide static

views of HO, based solely on Ec/I0 differences between servers.




11-12


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Notes




11-13


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Notes




11-14


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Notes




11-15


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Soft Handoff Increases Capacity

There are several important reasons to place in soft handoff any additional Base Stations that can bedetected by the mobile as soon as possible:

1. Improve voice quality: Cell boundaries usually offer poor coverage coupled with

increased interference from other cells. Traffic Channel diversity from additional cells will

improve voice quality.

2. Control mobile interference: While on a boundary of a cell, high Tx power of a mobile can

be a source of interference to mobiles in other cells. Power control from these cells is

important to reduce the interference.

3. Reduce dropped call probabilities: In handoff areas, the Forward link is most vulnerable.

A slow handoff process coupled with a vehicle moving at a high speed may cause a call to be

dropped if the mobile becomes unable to demodulate the Forward link transmitted from the

original cell, and looses the Handoff Direction message.

4. Increase RL capacity and coverage: Soft handoff considerably increases both the RL

capacity of a heavily-loaded cellular system and the coverage of each individual cell in a

lightly-loaded system.




11-16


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Notes




11-17


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Handoff Threshold

Depending on the tool implementation, the threshold used for HO can be related to T_Add orT_Drop.




11-18


80-W1527-2 Rev C


The Handoff Reduction Factor = 2.13

Handoff reduction factor is typically used to measure how many air links are required to supporteach individual user. When this factor increases, the call retention performance can be improved,

but cell capacity decreases.




11-19


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Notes




11-20


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Notes




11-21


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Notes




11-22


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Notes




11-23


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Notes




11-24


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Notes




11-25


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Notes




11-26


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Notes




11-27


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Notes




11-28


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Notes




11-29


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Notes




11-30


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HHO Zone Allocation

The HHO area defined by Ec/I0 thresholds is changing with load.




11-31


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Notes




11-32


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Notes





80-W1527-2 Rev C

11-33MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION

Search Windows and Propagation Delays

Search windows should be wide open to accommodate the propagation delays. Typically, the worst

case would correspond to propagation delays equivalent to the difference of the distance to thereference server and the distance to the farthest neighbor (plus eventual multipath). Once the

distance is found it can be converted in chips using:

( )810*3.00lightof speedc

(1228800)chipratew

metersindistanced

with

*.2___

=

=

=

=

c

wd N WinSrchestimated




11-34


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Notes




11-35


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Notes




11-36


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Notes




11-37


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PILOT_INC Parameter

The PILOT_INC parameter defines the set of PN offsets that the mobile will search, particularly forthe Remaining Set search.

Pilot_INC cannot be set only to increase the PN space. It needs to be set in accordance with the

required search window: if the propagation delay is longer than ½ Pilot_INC, the PN offset would

not be accurately estimated from the PN Phase.




11-38


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Notes




11-39


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Notes




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Notes




11-41


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Notes




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Notes




11-43


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Notes




11-44


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Generic Considerations

A cell not included in the Neighbor List has a low probability of being added to the Active Set,because the remainder set is searched infrequently. Even if reported, a remainder set sector

neighbor cell will not necessarily be added to the Active Set. The Base Station Controller (BSC),

based on vendor implementation, can ignore any reported set cells or, more commonly, report them

through the O&M.

The issue with Neighbor List length is one of balance. A short Neighbor List makes the search faster,

thus increasing the probability of detecting a fast-rising Pilot. On the other hand, a short Neighbor

List increases the risk of leaving out a required neighbor, thus failing a handoff.

The inverse could be said about a long list. The probability of leaving out a neighbor is low, but the

risk of not searching all the neighbors often enough increases the possibility of failing a handoff to afast-rising Pilot.




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Notes




11-46


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Using the Neighbor List

Neighbor List length can serve as a quality indicator, using the following process (the exact processdepends on the tool):

1. Run a simulation, low load.

2. Run the Neighbor List planning utility for very small overlap (1% or less).

3. Do not set a maximum Neighbor List length (unless the tool requires a limit).

4. Make the Neighbor List symmetric.

5. Study further any cell with more than 16 neighbors.

This limit of 16 on the Neighbor List is completely empirical. Adjust (increase) it to prioritize the

work.For a one-layer system, one carrier, 16 should be considered the maximum length for a Neighbor

List. Ideally, the length should be trimmed to 9 to 14—not by removing the low probability

neighbor, but by adjusting the RF configuration until the Neighbor List length is acceptable. This not

only reduces the Neighbor List length but, more importantly, reduces interference from other cells.




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Notes




11-48


80-W1527-2 Rev C


Location Areas

Ideally, paging zone planning should consider the loading on the common channels, particularly thePaging Channel (F-PCH).

Estimating the F-PCH load, and thus planning the zones, is beyond the scope of this course.




11-49


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Notes




11-50


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Notes




11-51


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Notes




11-52


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Notes




12-1

Section 12: Practical Considerations for Network Planning

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Notes




12-2


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Notes




12-3


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Notes




12-4


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Near Parts

Antenna near parts contribute additional loss or gain in the transmission line.

The standard does not provide guidance for antenna near parts, but they are all critical for

implementation.

Antenna near parts can be divided in two categories:

Always Considered:

– Antenna

– Feeder

– BTS reference point

Optional, depending on site implementation:

– Power booster

– TMA

– Diplexer

– Surge protector/lighting arrestor

– Bias injector

– Remote electrical tilt system

Each component has an impact on the Link Budget, so must be selected carefully.




12-5


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Notes




12-6


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Antenna Radiation Pattern

Antenna pattern is the most critical characteristic of an antenna. Null-fill pattern will likelyaffect prediction, but will have limited effect in urban environments. In this morphology, the

reflection and diffraction dominate to limit the accuracy of the prediction.

The quality of the upper sidelobes can affect interference at the edge of coverage. Pay

attention to this characteristic when high level downtilt will be applied. If the first upper

sidelobe points to the horizon, coverage (interference in this case) can be increased by the

difference between the first null and first upper sidelobe (typically 15 to 25 dB).




12-7


80-W1527-2 Rev C


Surge Protectors/Lightning Arrestors

Typical attenuation for surge protectors/lightning arrestors:

Polyphaser: < 0.1 dB

Huber & Suhner: < 0.2 dB

Additional considerations:

If TMA or RET is used, the arrestor should not block the bias or command.

The connector must be compatible with the other devices!




12-8


80-W1527-2 Rev C


Tails or Jumpers

The following table shows typical linear losses (dB/100 m):

Cable type Size Frequency

---------------------- --------- -------------------------------------------------

900 MHz 1800 MHz 2100 MHz

Andrew FSJ1-50A 1/4" 18.4 26.9 29.2

Andrew ETS1-50T 1/4" 18.1 26.2 28.5

Andrew FSJ2-50A 3/8" 12.5 18.5 20.1

Andrew ETS2-50T 3/8" 13 19.4 21.2

Andrew FSJ4-50B 1/2" 11.1 16.6 18.1

For 3 m length, connector loss cannot be neglected.




12-9


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Notes




12-10


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Notes




12-11


80-W1527-2 Rev C


LNA and link balance

With the addition of a TMA, the Reverse link MAPL increases. The feeder loss can typicallybe set to zero (0) and the noise figure improves. In contrast, the Forward link is impacted by

the through loss of the TMA.

There are three schools of thought about when or whether to use LNAs:

1. Install them everywhere.

2. Install them only when needed, i.e., when the RL is limiting.

3. Plan them everywhere (for site acquisition and tower loading analysis) but install

only where needed.

During analysis, it is much easier to run the simulation without LNAs, optimize the RF

configuration, and then add LNAs when the main cause of blocking is insufficient Reverse

link.




12-12


80-W1527-2 Rev C


LNA Noise Factor Calculation

For an active system, Receiver (Rx) and LNA, the gain and noise factor should beknown.

– Example:

NFRx: BTS noise figure, typically 2 to 5 dB (1.6 to 3.2)

NFLNA: LNA noise figure, typically 1.5 to 2.5 dB (1.4 to 1.8)

GNLA: LNA gain, typically 12 to 25 dB (15.8 to 316)

For a passive system, feeder (feed), the gain is the inverse of the loss, the noise

factor is the loss.

– Example: Gfeed: Feeder gain = - feeder loss, typically -2 to -6 dB (0.6 to 0.2)

NFfeed: Noise figure of the feeder, set as feeder loss 2 to 6 dB (1.6 to 4)

By summing the passive components, the equation can be used with only three

devices.




12-13


80-W1527-2 Rev C


Notes




12-14


80-W1527-2 Rev C


Antenna Gain

Gain of the antenna is a ratio of the transmitted power in the direction of the antenna to theuniform value of the Reference antenna.

If the Reference antenna is an isotropic radiator, the absolute gain (dBi) is calculated.

If the Reference antenna is a half-wave dipole, the relative gain (dBd) is calculated.

Absolute gain (dBi) = Relative gain (dBd) + 2.15 dB

Front-to-Back Ratio

A minimum of 20 dB is recommended.

Elevation (vertical) Beam Width

Beamwidth depends on the antenna gain and size (and number of elements). A nominal

value of 7 degrees is recommended for PCS frequencies. For lower frequencies (450 or 850

MHz), where size restrictions limit the number of elements, the vertical beamwidth is

typically limited to 10 to 20 degrees.

Upper Sidelobe Suppression

Sidelobes up to 20 degrees above the main lobe shall be suppressed by 18 dB relative to the

peak gain.




12-15


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Notes




12-16


80-W1527-2 Rev C


Null-Fill and morphologies

In urban area, assuming that the antenna are not located high above ground level, thescattering is generally sufficient to avoid creating coverage hole directly below the antenna.

In rural area, or more generally when antenna are mounted very high above ground, null-fill

prevents the apparition of coverage holes just below the antenna.




12-17


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Notes




12-18


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Notes




12-19


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Antenna Downtilt: EDT and MDT

Downtilt can be achieved either electrically or mechanically.

For Electrical downtilt (EDT), the phase between the different antenna elements is varied to

steer the antenna pattern. This same concept is used in beam forming antennas.

To use Mechanical downtilt (MDT), a tilting bracket typically must be included during

antenna installation. MDT is achieved simply by changing the antenna mounting angle.




12-20


80-W1527-2 Rev C


Optimum Downtilt

[1] J.Niemela, T.Isotalo, J.Lempiainen, “Optimum Antenna Downtilt Angles for MacrocellularWCDMA Network,” EURASIP Journal on Wireless Communications and Networking 2005:5.

Note that this empirical formula was set to match results of simulations performed at 2100

MHz while trying to increase the capacity of the system. Therefore the resulting downtilt

when applying the formula would be applicable in capacity design (not coverage), with

short site-to-site distance.




12-21


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Notes




12-22


80-W1527-2 Rev C


EDT vs. MDT: Narrow (V) Beam Antenna

For narrow beam antennas, similar attenuation can be achieved in the bore sight witheither mechanical or electrical DT. The main difference is outside of the bore sight, where

MDT shows less attenuation.




12-23


80-W1527-2 Rev C


EDT vs MDT: Large (V) Antenna Beamwidth

As the antenna beamwidth (V) increases, the difference between electrical and mechanicalDT increases. For EDT, larger attenuation can be achieved with the same DT angle.




12-24


80-W1527-2 Rev C


EDT

EDT always changes the Vertical Radiation Pattern. For many types of antennas, thisincreases side lobe strength, and decreases separation between the main lobe and side lobe.

In this example:

0 EDT

Side lobe strength: -20.2 dB

Side lobe separation from main lobe: 21°

12 EDT

Side lobe strength: -11.4 dB

Side lobe separation from main lobe: 18°

This phenomenon can significantly increase Pilot pollution on upper floors in an urban

area.




12-25


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Notes




12-26


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Notes




12-27


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Notes




12-28


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Site Survey Checklist

Site selection can only be done after visiting the candidate sites. Prior to the site survey,conduct research to determine the best candidate; however, only a site visit can reveal all

the potential problems with a site.

Maintain a detailed site survey checklist and photographs to ensure accurate and consistent

data sharing within a team.




12-29


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Notes




12-30


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Notes




12-31


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Notes




12-32


80-W1527-2 Rev C


Site Off-Grid

Selecting a site off-grid is a necessary evil in a commercial deployment. Site acquisition anduneven traffic distribution are the main factors that impose the selection of sites off-grid.

Compared with the same area and same number of sites, site off-grid will have the effect of:

Degrading the frequency reuse efficiency (Ff), both in terms of average and mainly

standard deviation.

Increasing the HO reduction factor.

From this observation, we can conclude that when sites must be selected off-grid, additional

optimization will be required to ensure system performance.




12-33


80-W1527-2 Rev C


Height Difference

If sites must be off-height (usually for site acquisition reasons), the negative impact of sitesoff-grid is increased.

In such case, it become even more important to:

Control the coverage of each cell.

Control the overlap between cells.

Limit the number of cells detected in a given area.




12-34


80-W1527-2 Rev C


Site Off-Grid and Height Distance

The plots shown in this course have been overviews of an entire planned area. Such plotsare good for a high-level view, but do not help illuminate or solve specific problems.Detailed maps are needed for problem solving.

When handoff cursors are available, it is useful to verify whether the best server in a givenarea is the expected one. In both of these examples, calls are in HO with a distant server andthe main issue is an increase in other cell interference. The impact is greater than what isshown. Often, a distant site can be detected, but it is not strong enough to be a HO candidate,or even to be promoted to the Active Set. The result is increased interference, without thepossibility of using the signal.

The same concept is shown in the best server plot, where it is easier to visualize. Thechallenge in both cases is to distinguish normal conditions (due to terrain, for example)from other issues, such as poor site selection or incomplete optimization.

These additional views also can help identify problems:

Individual cell Ec/I0 – Helps identify cells that are detected at a given level far away.

Cell count (above Ec/I0, HO candidate, etc.) – Helps identify areas in which too manyservers are detected.

Bin query – Helps identify the servers available in a given Bin. This information issimilar to the two previous plots, but provides numerical data for further analysis.




12-35


80-W1527-2 Rev C


High Capacity Solutions

High capacity solutions should be treated differently for Forward and Reverse links,according to which is the limiting link. On the Reverse link, capacity can be increased by any

device that improves the Eb/Nt requirement, for example, MUD. On the Forward link, the

goal to reduce the required Eb/Nt is the same; however, the implementation differs because

only the transmit chain is available, for example, Tx diversity.




12-36


80-W1527-2 Rev C


Repeater Sites

There are many reasons to install a repeater rather than a BTS. As an example, equipmentsize can be a driver. In this case, not only the size of the equipment (BTS or repeater) itself,

but also the size of the antenna system (antenna, TMA, feeder…).

For the antenna system, for a repeater, it is necessary to consider configuration that would

allow achieving the proper isolation between the donor and server antenna. This

requirement affects site acquisition because two antenna positions must be available, with

sufficient separation.

Carefully consider the installation of a repeater to extend coverage without adding capacity.

A repeater does not increase the coverage in CDMA, but instead changes the coverage area.Forward link coverage is extended regardless of capacity, but Reverse link coverage is

reduced due to the increased noise at the BTS. Depending on the limiting link, coverage may

be reduced (worst case) or moved (best case). In this last case, the coverage is extended in

the repeater coverage area, but at the expanse of a reduction of the main antenna area.




12-37


80-W1527-2 Rev C


Repeater Sites Details

Modeling a repeater can be challenging in CDMA. Considering only the path loss will notgive accurate results. The main limitation in repeater modeling is how to simulate

interference.

To model all interference on the Forward link, the tool should complete a path loss

analysis on the donor side. This implies using the donor antenna pattern in the

analysis, with an RF model that is compatible with the propagation condition (line of

sight).

On the Reverse link, modeling interference implies evaluating both the rise over

thermal and the increased Eb/Nt requirements due to the lack of diversity.

If a tool is used to evaluate the hardware requirements, the last aspect to consider is traffic.

Ideally, traffic at the donor site should include the sum of the traffic in the primary coverage

area and the repeater coverage area.




12-38


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Notes




12-39


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Notes




12-40


80-W1527-2 Rev C


Comments/Notes




13-1

Section 13: Overlays

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Notes




13-2


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Notes




13-3


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Notes




13-4


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Notes




13-5


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Limiting Service

The expected data rate at cell edge should be considered when determining the limiting service orthe limiting link. If 9.6 kbps is required, then EV-DO and voice have similar (if not identical) MAPL. If

the system is planned for higher data rates (38.4 kbps or 153 kbps typically on the Reverse link),

then the EV-DO footprint would be reduced compared to voice.

Capacity Limitation

For capacity, the limiting service depends on the business model and the number of carriers that can

be used for each of the services.




13-6


80-W1527-2 Rev C


Hotspot Deployment

Hotspot deployment of EV-DO can be done initially to relieve capacity constraints in a CDMA2000system, if the capacity constraint is for data usage. As discussed in Section 9,

EV-DO capacity (sector throughput) can be estimated at 2 to 4 times more than CDMA2000 (data).

However, subscriber expectations should be carefully managed. Hotspot deployment can result in

low perceived QoS because the high data rate available with EV-DO can be achieved only in the

hotspot.




13-7


80-W1527-2 Rev C


Notes




13-8


80-W1527-2 Rev C


Hybrid Mode

A hybrid EV-DO terminal is constantly monitoring the Ec/I0 of both the 1X and EV-DO networks. 1Xsystem acquisition normally takes place when the Ec/I0 of a 1X system becomes stronger than the

Ec/I0 of EV-DO minus 7 dB, which can be interpreted as the equal power point of 1X and EV-DO, if

the 1X system is fully loaded.




13-9


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Notes




13-10


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Notes




13-11


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Notes




13-12


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Notes




13-13


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Notes




13-14


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Notes




13-15


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Notes




13-16


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Different Frequency Bands

When EV-DO is deployed on lower frequencies, it causes higher interference if the same antennasare used for both 1X and EV-DO. There are more rejections due to high RoT, but overall system GoS

is higher due to better in-building coverage.




13-17


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Notes




13-18


80-W1527-2 Rev C


Comments/Notes




14-1

Section 14: Capacity Planning Considerations

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Notes




14-2


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Notes




14-3


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Notes




14-4


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Notes




14-5


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Notes




14-6


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Notes




14-7


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Capacity

For spreadsheet design, the easiest way to estimate capacity is by morphology. However, actualtraffic distribution depends on multiple parameters.




14-8


80-W1527-2 Rev C


Typical Capacity Design

For data services, the capacity requirement can be expressed in various ways:

Monthly Data Usage – Typically in MB; can be used to estimate busy hour usage.

Busy Hour Usage – Can be given either in KB or average kbps.

Busy Hour Usage, Application – Considers number of sessions, not the volume of data.

Convert to KB or kbps, based on the application.

For RF network planning tools, convert the data into kbps or Erlangs.

Because data and voice usage do not follow the same pattern, you may need two traffic requirement

tables:

Data busy hour usage.

Voice busy hour usage.

At this stage, it is very important to agree on the peak-to-average ratio, and make sure all members

of the design team use the same ratio.




14-9


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Notes




14-10


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Notes




14-11


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Notes




14-12


80-W1527-2 Rev C


EV-DO Network Statistics to Monitor Capacity Growth

Simultaneous active flows–

A flow is considered active if the reservation for the flow hasbeen turned on.

Flow-specific traffic utilization – Count of bytes transmitted for a given flow / Count of

transmitted bytes for all flows over the sample period.

Per-flow utilization –Count of slots transmitted for a given flow / Count of transmitted slots

Forward Physical Layer throughput – Total number of Physical Layer Bits transmitted

over a given time interval.

Reverse Physical Layer throughput – Total number of Physical Layer Bits transmitted over

a given time interval.

Packet drop due to exceeding the delay limit –

Count of IP packets dropped due toexceeding the delay limit / (Count of IP packets transmitted + Total number of drops)

Driver flow buffer utilization – Count of packets in the buffer / Maximum buffer capacity.




14-13


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Notes




14-14


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Notes




14-15


80-W1527-2 Rev C


Capacity Planning Considerations – Introduction

RF optimization–

Controlling interference helps reduce FL power utilization. Consider thisapproach when the measured sector capacity falls below expectations. RF optimization mainlyrelieves capacity congestion on the FL (high power utilization) but also improves the HO reductionfactor. To some extent, it also improves the RL by reducing cell overlap.

Adding RC4– This action mainly relieves Walsh code channel congestion. Consider this approachonly when forward power utilization is low, because RC4 is less efficient (in terms of powerutilization) than RC3. When forward power utilization is high, adding RC4 may only minimallyimprove overall system capacity and shift the cause of congestion from code channel blocking toforward power blocking. RC4 is typically introduced dynamically: the MS is assigned RC3 or RC4 tobalance both code channel and power utilization.

Change in power setting – Changing the power allocation of the control channels can increase thepower available for the traffic channel, but it can also change the FL/RL balance. An alternative wayto increase power available for the traffic channel is to increase the total power available (HPArating) and set the common channel to the same absolute power. This technique can work if appliedto an isolated sector. Applying it to all sectors in an area increases FL interference which increasesthe power requirement for all the FL channels, resulting in no gain overall.

Additional carriers – Capacity can be increased by adding carriers in the cells/sectors of increasedtraffic demand. Adding carriers increases all the resources (code channel, forward power, etc.)except channel elements. Vendor implementation dictates if the existing channel element pool canbe shared across carriers (typical). If CEs are shared across carriers, CE utilization should bemonitored to determine when to increase the resource pool.




14-16


80-W1527-2 Rev C


Capacity Planning Considerations – Introduction

Cell (or sector) splitting–

Capacity can be increased by adding cell sites (or sectors). RFoptimization also should be done when cells (or sectors) are added to the system. Without RF

optimization, the additional cells (or sectors) will increase FL interference and the HO distribution,

both of which could reduce system capacity.

Introduction of EV-DO –If a 1X system is heavily loaded with data traffic, adding EV-DO can

increase capacity by increasing spectrum efficiency.




14-17


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Notes




14-18


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Notes




14-19


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Notes




14-20


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Notes




15-1

Section 15: Course Summary

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Notes




15-2


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Notes




15-3


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Summary

This Link Budget excerpt illustrates:

Maximum path loss = EIRP

– Sensitivity

+ Receiver loss and gain

+ Propagation components

From this maximum path loss one can determine a Reverse link value, which is equivalent to a

signal strength design level.




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Equality Coverage Comparison

The normal setting is a combination of both Link Budgets (equal coverage and equal power).Coverage should be equal for all classes of service (conversational speech, streaming, interactive).

For a given class of service (e.g., interactive) the power setting will be the same for all data rates. In

this case, the power should be set to provide coverage over the entire cell at the minimum

acceptable data rate.




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CDMA Bands

The 800 MHz band is the most commonly used band for CDMA operations. More than two-thirds ofthe CDMA mobiles are in this band. This band is also called the US Cellular band or band class 0 in

CDMA terminology.




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Notes




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Notes




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Notes




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Different Frequency Band

Deployment of EVDO on lower frequency always causes higher interference if the same antennasare used for both 1x and EVDO; number of rejection due to high ROT in this case is bigger but overall

system GoS is higher due to better Inbuilding coverage.




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Notes




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Notes




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Notes




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Notes





80-W1527-2 Rev C

Documents

80-W1527-2 Rev.C CDMA2000 1x and 1xEV-DO Network Planning