EVDO RF Planning Guide

1xEV-DORF PLANNING GUIDESOFTWARE RELEASE4

ENGLISHMAY 200568P09267A70-A

SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE

NoticeWhile reasonable efforts have been made to assure the accuracy of this document, Motorola, Inc. assumes no liability resulting from any inaccuracies or omissions in this document, or from use of the information obtained herein. The information in this document has been carefully checked and is believed to be entirely reliable. However, no responsibility is assumed for inaccuracies or omissions. Motorola, Inc. reserves the right to make changes to any products described herein and reserves the right to revise this document and to make changes from time to time in content hereof with no obligation to notify any person of revisions or changes. Motorola, Inc. does not assume any liability arising out of the application or use of any product, software, or circuit described herein; neither does it convey license under its patent rights or the rights of others.It is possible that this publication may contain references to, or information about Motorola products (machines and programs), programming, or services that are not announced in your country. Such references or information must not be construed to mean that Motorola intends to announce such Motorola products, programming, or services in your country.

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REV091302

1xEV-DO【RF PLANNING GUIDE】

Table of Contents

List of Table ......................................................... iiiList of Figures ........................................................ vGeneral Safety ....................................................... viiForeword ............................................................... ixRevision History ...................................................... xi

Chapter 1: Introduction .......................................................1-1

Chapter 2: What are some basic things to know? ..........................2-1

Chapter 3: What is the RF Coverage of 1xEV-DO? ..........................3-1

Chapter 4: What is the RF Capacity of 1xEV-DO? ..........................4-1

Chapter 5: What is the Throughput of 1xEV-DO? ...........................5-1

Chapter 6: What other things to consider for RF planning? ............6-1

MAY 2005 RF PLANNING GUIDE i

Table of Contents - continued

ii RF PLANNING GUIDE MAY 2005


List of Table

Table 2-1: Reverse Channel Chips/Bit ..............................................2-8Table 2-2: Default Data Channel Gain ..............................................2-8Table 2-3: Reverse Eb/Nt Values ...................................................2-10Table 2-4: Forward Channel Chips/Bit ..............................................2-10Table 2-5: Ec/Nt to DRC Mapping Example ...........................................2-12Table 3-1: Example Hata Propagation Loss Slope and Intercept for Reverse Link: ....3-4Table 3-2: Example Hata Propagation Loss Slope and Intercept for Forward Link: ....3-4Table 3-3: Example Coverage Reliability for Slopes Obtained Previously: ...........3-5Table 3-4: 1xEV-DO Reverse RF Link Budget .........................................3-6Table 3-5: Pathloss for Urban area w/ antenna height of 30 m

(Top: In-vehicle, Bottom: In-building) ..3-7Table 3-6: Pathloss for Suburban area w/ antenna height of 30 m

(Top: In-vehicle, Bottom: In-building) ..3-7Table 3-7: Pathloss for Open Rural area w/ antenna height of 45 m

(Top: In-vehicle, Bottom: In-building) ..3-7Table 3-8: 1xEV-DO Forward RF Link Budget .........................................3-8Table 3-9: Pathloss for Urban area w/ antenna height of 30 m

(Top: In-vehicle, Bottom: In-building) ..3-9Table 3-10: Pathloss for Suburban area w/ antenna height of 30 m

(Top: In-vehicle, Bottom: In-building) ..3-9Table 3-11: Pathloss for Open Rural area w/ antenna height of 45 m

(Top: In-vehicle, Bottom: In-building) ..3-9Table 4-1: Capacity Estimates for Reverse Link ....................................4-7Table 5-1: Scheduling Algorithm Comparison ........................................5-3Table 5-2: Table 20: Effective Rates for Forward Link .............................5-4Table 5-3: Data Rates at Various Layers ...........................................5-7Table 5-4: Size of Reverse Link Payload ...........................................5-10

MAY 2005 RF PLANNING GUIDE iii

List of Table - continued

iv RF PLANNING GUIDE MAY 2005


List of Figures

Figure 2-1: Forward Link Power Allocation ..........................................2-3Figure 2-2: 1xEV-DO Reverse Link Structure .........................................2-5Figure 2-3: 1xEV-DO Forward Link Structure .........................................2-5Figure 2-4: Reverse Link Shared Energy .............................................2-7Figure 2-5: Multipath Signal (Îor) with Interference from Other Users (Ioc) .......2-9Figure 2-6: Multipath Signal (Îor) with Interference from Other Sites (Ioc) .......2-11Figure 2-7: Representative Carrier Configurations ..................................2-14Figure 2-8: C/I for Different Carrier Configurations ...............................2-15Figure 4-1: Link Capacity ..........................................................4-3Figure 4-2: Power Capacity .........................................................4-4Figure 4-3: Number of Users Versus SINR ............................................4-5Figure 4-4: Loading Factor Versus Noise Rise .......................................4-7Figure 5-1: DRC versus Time ........................................................5-3Figure 5-2: Multiple User Data .....................................................5-5Figure 5-3: Single User Data .......................................................5-6Figure 5-4: Overhead Bits at Each Layer ............................................5-6Figure 5-5: Sector and End-User Throughput .........................................5-8Figure 5-6: MaxRate Determination ..................................................5-11Figure 5-7: CurrentRateLimit Determination .........................................5-12Figure 5-8: MaxPwrCapableRate Determination ........................................5-13

MAY 2005 RF PLANNING GUIDE v

List of Figures - continued

vi RF PLANNING GUIDE MAY 2005

General Safety

Remember! . . . Safety depends on you!!

The following general safety precautions must be observed during all phases of operation, service, and repair of the equipment described in this manual. Failure to comply with these precautions or with specific warnings elsewhere in this manual violates safety standards of design, manufacture, and intended use of the equipment. Motorola, Inc. assumes no liability for the customer’s failure to comply with these requirements. The safety precautions listed below represent warnings of certain dangers of which we are aware. You, as the user of this product, should follow these warnings and all other safety precautions necessary for the safe operation of the equipment in your operating environment.

Ground the instrument

To minimize shock hazard, the equipment chassis and enclosure must be connected to an electrical ground. If the equipment is supplied with a three-conductor ac power cable, the power cable must be either plugged into an approved three-contact electrical outlet or used with a three-contact to two-contact adapter. The three-contact to two-contact adapter must have the grounding wire (green) firmly connected to an electrical ground (safety ground) at the power outlet. The power jack and mating plug of the power cable must meet International Electrotechnical Commission (IEC) safety standards.

Do not operate in an explosive atmosphere

Do not operate the equipment in the presence of flammable gases or fumes. Operation of any electrical equipment in such an environment constitutes a definite safety hazard.

Keep away from live circuits

Operating personnel must:• not remove equipment covers. Only Factory Authorized Service Personnel

or other qualified maintenance personnel may remove equipment covers for internal subassembly, or component replacement, or any internal adjustment.

• not replace components with power cable connected. Under certain conditions, dangerous voltages may exist even with the power cable removed.

• always disconnect power and discharge circuits before touching them.

NOTERefer to Grounding Guideline for Cellular Radio Installations (P/N 68P81150E62)

MAY 2005 RF PLANNING GUIDE vii

General Safety — continued

Do not service or adjust alone

Do not attempt internal service or adjustment, unless another person, capable of rendering first aid and resuscitation, is present.

Use caution when exposing or handling the CRT

Breakage of the Cathode-Ray Tube (CRT) causes a high-velocity scattering of glass fragments (implosion). To prevent CRT implosion, avoid rough handling or jarring of the equipment. The CRT should be handled only by qualified maintenance personnel, using approved safety mask and gloves.

Do not substitute parts or modify equipment

Because of the danger of introducing additional hazards, do not install substitute parts or perform any unauthorized modification of equipment. Contact Motorola Warranty and Repair for service and repair to ensure that safety features are maintained.

Dangerous procedure warnings

Warnings, such as the example below, precede potentially dangerous procedures throughout this manual. Instructions contained in the warnings must be followed. You should also employ all other safety precautions that you deem necessary for the operation of the equipment in your operating environment.

WARNINGDangerous voltages, capable of causing death, are present in this equipment. Use extreme caution when handling, testing, and adjusting.

viii RF PLANNING GUIDE MAY 2005

Foreword

Scope of manual

This manual is intended for use by cellular telephone system craftspersons in the day-to-day operation of Motorola cellular system equipment and ancillary devices.

This manual is not intended to replace the system and equipment training offered by Motorola, although it can be used to supplement or enhance the knowledge gained through such training.

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NOTEPresents additional, helpful, non-critical information that you can use.

IMPORTANTPresents information to help you avoid an undesirable situation or provides additional information to help you understand a topic or concept.

CAUTIONPresents information to identify a situation in which damage to software, stored data, or equipment could occur, thus avoiding the damage.

WARNINGPresents information to warn you of a potentially hazardous situation in which there is a possibility of personal injury.

MAY 2005 RF PLANNING GUIDE ix

Foreword — continued

The following typographical conventions are used for the presentation of software information:• In text, sans serif BOLDFACE CAPITAL characters (a type style

without angular strokes: in other words, SERIF versus SANS SERIF) are used to name a command.

• In text, typewriter style characters represent prompts and the system output as displayed on an operator terminal or printer.

• In command definitions, sans serif boldface characters represent those parts of the command string that must be entered exactly as shown and typewriter style characters represent command output responses as displayed on an operator terminal or printer.

• In the command format of the command definition, typewriter style characters represent the command parameters.

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If you have problems regarding the operation of your equipment, please contact the Customer Network Resolution Center (CNRC) for immediate assistance. The 24 hour telephone numbers are: North America. . . . . . . . . . . . . . . . . . . . . . . . +1-800-433-5202 Europe, Middle East, Africa . . . . . . . . . . . . . +44- (0) 1793-565444 Asia Pacific . . . . . . . . . . . . . . . . . . . . . . . . . . +86-10-88417733 Japan & Korea. . . . . . . . . . . . . . . . . . . . . . . . +81-3-3444-4935 Latin American Countries . . . . . . . . . . . . . . . +51-1-212-4020 For further CNRC contact information, contact your Motorola account representative.

x RF PLANNING GUIDE MAY 2005

Revision History

Manual Number

68P09267A70-A

Manual Title

1xEV-DO RF PLANNING GUIDE

SOFTWARE RELEASE4

Version Information

The following table lists the manual version, date of version, and remarks on the version.

Version Level

Date of Issue Remarks

1 FEB 2005 FOA Version

2 MAR 2005 Correct some errors

3 APR 2005 Add review comments

A MAY 2005 GA Version

xi RF PLANNING GUIDE MAY 2005

xii RF PLANNING GUIDE MAY 2005

Table of Contents

Chapter 1: Introduction

Chap.1-1. What is the purpose of this document? ............................ 1-3

Chap.1-2. How is this document structured? ................................. 1-3

Chap.1-3. What are some useful references? ................................. 1-4

Chap.1-4. What terminology is used in this document? ....................... 1-5

MAY 2005 RF PLANNING GUIDE 1-1

[Chap. 1] Table of Contents - continued

1-2 RF PLANNING GUIDE MAY 2005

1
1-1. What is the purpose of this document?
The document is intended to provide a reference for methods and examples to common RF system planning issues for 1xEV-DO. This document is not intended as a reference for detailed RF design, equipment planning, or other such issues. The target audience of this document is RF system design engineers planning to add 1xEV-DO to their existing 1x market. It is highly recommended to consult with a Motorola RF system design engineer when evaluating design choices.

1-2. How is this document structured?

This document is structured in a question and answer format. Questions that an RF system design and planning engineers may ask regarding initial 1xEV-DO RF planning are answered, along with some specific examples. Engineers can search the table of contents on the previous page for questions they may have.


1

1-3. What are some useful references?

Here is a list of generally useful documents related to 1xEV-DO and RF issues.

The following standards (downloadable from: http://www.3gpp2.org) were used for reference:

1. C.S0007-A_v2.0 IOS (inter-operability specification) standard that describes message flows between various devices necessary for setting up, tearing down, and handing off calls.

2. C.S0024-0_v3.0 The main standard that describes the layers, messages, and parameters that make the 1xEV-DO link.

3. C.S0029-0_v2.0 Test Application Specification (TAS)

4. C.S0032-0_v1.0 Minimum Performance Specification (MPS) of the reverse link channels.

5. C.S0033-0_v1.0 Minimum Performance Specification (MPS) of the forward link channels.

Other documents:

CDMA/CDMA2000 1X RF Planning Guide

The classic Motorola document for CDMA RF system planning topics. Many of the concepts in that document can be applied to 1xEV-DO systems as well. This guide can be obtained from Motorola Technical Information Products and Services with part number 68P09248A69.


1

1-4. What terminology is used in this document?

Abbreviations Description

1xEV-DO 1X Evolution Data Only (or Data Optimized)

ACI Adjustment Carrier Interface

ACK Acknowledgement

AN Access Network (1xEV-DO BTS)

AP Access Point (same as AN)

AT Access Terminal (1xEV-DO mobile terminal)

AWGN Additive White Gaussian Noise

BTS Base station transceiver subsystem

C/I Carrier to Interference Ratio

DRC Data Rate Control

Frame [data] 16 consecutive slots of data

MAC Medium Access Control

MPS Minimum Performance Specification

PER Packet Error Rate

RNR Reverse Noise Rise

RRI Reverse Rate Indicator

Slot [data] Minimum unit of data (1.67 msec duration)

SINR Signal to Interference plus Noise Ratio

SNR Signal to Noise Ratio


1
Notes

Table of Contents

Chapter 2: What are some basic things to know?

Chap.2-1. What is 1xEV-DO? ................................................. 2-3

Chap.2-2. What is the basic structure of the 1xEV-DO RF link? .............. 2-5

Chap.2-3. Do we need to make any adjustments to T_Add & T_Drop setting? .... 2-6

Chap.2-4. How do we estimate the SNR, considering multi-path? .............. 2-7

Chap.2-5. What frequency channels(carriers) can be used for 1xEV-DO? ....... 2-13




2-1. What is 1xEV-DO?

2

1xEV-DO (Evolution-Data Only/Optimized) is a separate but related standard in the family of 3GPP2 cdma2000 group. It offers a high rate data only solution in the same frequencies with similar RF characteristics as the main cdma2000 1x standards, allowing for reuse of the same RF equipment (i.e. base station frames, base station cages, antennas transmission lines, power amplifiers). A separate carrier frequency is required for 1xEV-DO as this standard does not support voice and data on the same carrier frequency.

The reverse link for 1xEV-DO is similar to the reverse link of cdma2000 1x. For 1xEV-DO, the fundamental channel and forward power control sub-channel have been removed. They have been replaced with 3 new channels: RRI (reverse rate indicator), DRC (data rate control), and ACK (acknowledgement).

The forward link for 1xEV-DO has been simplified to a link where all channels including overhead are separated in time, allowing each channel to use full power during it transmission duration. There is no power control on the forward link ? it is always constant power. The following figure provides an illustration of the forward link power allocation difference between cdma2000 1x and 1xEV-DO.

Figure 2-1: Forward Link Power Allocation

Control C

hannel

Time

Sector TxPower

1xEV-DO Forward Link Power Allocation

Total D

ata

Pilot Channel

Control C

hannel

Time

Sector TxPower

1xEV-DO Forward Link Power Allocation

Total D

ata

Pilot Channel

Pilot Channel

Page Channel

Sync Channel

Time

Sector TxPower

cdma2000 1x Forward Link Power Allocation

Total Traffic

Unused Margin

Pilot ChannelPilot Channel

Page ChannelPage Channel

Sync ChannelSync Channel

Time

Sector TxPower

cdma2000 1x Forward Link Power Allocation

Total Traffic

Unused Margin


2

The AT constantly monitors the C/I levels of nearby sites and sends (on the DRC channel) the data rate it currently estimates is possible of achieving over the forward link. Each site receives the DRC data rate information from the various ATs it is capable of serving, and assigns time slots based on a scheduling algorithm. When an AT receives a slot of data it responds on the ACK channel to let the system know if it was able to receive the data completely or not.

The 1xEV-DO air interface standard specifies a forward link instantaneous peak data rate of 2.4 Mbps and a reverse link peak data rate of 153 kbps. The interface is optimized for bursty, non-real time data, large forward link data bursts, large file transfer and full web browsing. It will support data services only; it does not support voice or concurrent services. It will require a data-only dedicated carrier. With hybrid AT units, it will be seamlessly backward compatible with IS95-A/B and 1X.

Motorola's 1xEV-DO solution allows sharing of RF equipment with currently existing 1X systems. A new MCC-DO card is added to the Motorola BTS, but the BBX, LPA, antenna, and other RF antenna is shared by both systems. Except for the PDSN, most network side equipment including spans out of the BTS is not shared by the 1X and DO.


2

2-2. What is the basic structure of the 1xEV-DO RF link?

On the reverse link there are 5 channels: DRC, ACK, RRI, Data, and pilot. The RRI channel is time multiplexed with the pilot channel. The pilot channel is power controlled and the 3 remaining channels' gains are referenced to the pilot. The ACK channel is only transmitted when responding to data received on the forward link; and its data only takes up half a slot duration. The DRC channel is offset by half a slot to allow for quicker feedback to the system on C/I conditions.

Each slot of the forward link is sub-divided into 2 half-slots. The center of each half-slot contains the pilot channel surrounded by the MAC channel. The MAC channel carries power and rate control data for the reverse link. The remainder of the slot is used for sending traffic or control data.

Figure 2-2: 1xEV-DO Reverse Link Structure

Data

DRC

ACK

Pilot+ RRI

RRI(1/8 slot) Pilot (7/8 slot)

1/2 Slotin response to FwdLink data received

Offset by 1/2 Slot

1.67 ms

Reverse Link16 Slots = 26.67 ms

Figure 2-3: 1xEV-DO Forward Link Structure

1.67 ms

Forward Link

Traffic orControl

Pilot

MAC

All slotstransmittedat max power

16 Slots = 26.67 ms


2

2-3. Do we need to make any adjustments to T_Add & T_Drop setting?

The expected RF coverage is expected to be similar for both 1X and 1xEV-DO systems. The reverse link coverage is equivalent for the lowest rate (9.6k). It is generally recommended to maintain the same coverage for both technologies. Where a pre-existing 1X system has a small cell radius due to capacity instead of coverage purposes, it is reasonable to deploy a 1xEV-DO system at a larger radius than 1X as long as the radius does not exceed 1xEV-DO coverage limitations. PN planning concepts for 1X should also be applicable to DO.

One thing to be aware of is the difference between T_Add and T_Drop values that are used to obtain the same desired SHO in 1xEV-DO as exist in cdma1X. These values should be several dB higher than cdma1X to account for the difference in Pilot to Traffic power (See Figure 2-1 in Chapter 2-1). For 1X, Pilot is usually about 20% of total power. For DO, Pilot is 100% of total power. Also, there may be some difference in the total power between 1xEV-DO and cdma1X at the same base station.

The formula for converting T_Add used in cdma1X to an appropriate value for 1xEV-DO, is:

T_Add_DO = 10*log10(10^(T_Add_1X/10) * (PowerDifference) ) where, PowerDifference = DO Pilot Power / 1X Pilot Power

Assuming T_Add_1X is -16dB and the PowerDifference is 7.5 (ie, DO full power is 7.5x that of cdma1X pilot power), then the T_Add for 1xEV-DO would be:

T_Add_DO = 10*Log10(10^(-16/10) * 7.5) = 10*Log10(0.19) = -7.2dB


2

2-4. How do we estimate the SNR, considering multi-path?

The power from the other channels as well as the total power of all other mobiles contributes to the noise of the power-controlled pilot channel. The following figure shows how energy is shared between channels on the reverse link.

Equations used for calculation of key SNR values for the reverse link are:

Ior/Ec = 1 + DRCChannelGain + ACKChannelGain/2 + DataChannelGain [Eq 2-1]

(Note_1: DRCChannelGain should be divided by DRCLength if Gating is "on".)

(Note_2: AckChannelGain is reduced by half because it occupies a half-slot.)

Pilot Ec/Io = 1 / (Ioc/Îor + 1) / (Ior/Ec) = Ratio of Pilot chip energy to total energy received at the AN [Eq 2-2]

(Note: Îor = Sum( Îor[j]), for j multipaths)

Data Eb/Nt = Chips/Bit * Channel_Gain / (Ior/Ec) * Sum( Îor[i] / (Ioc + Sum( Îor[j, j != i] ))) [Eq 2-3] = Ratio of multipath Data bit energy to Noise received at the AN

where,Eb : Energy per BitEc : Energy per ChipÎor : Total energy of channel at receive antenna of ANIoc : Total energy of other interfering channels at receive antenna of ANIor : Total energy of channel at transmit antenna of ATNt : Total energy of noise power at receive antenna of ANIo : Total energy (signal plus interference) at the receive antenna of AN = Îor + Ioc + NtChips/Bit = <see table>

Figure 2-4: Reverse Link Shared Energy

En

erg

Pilot Ec

Ior

DRC Ec = Pilot Ec * DRCChannelGain

Ack Ec = Pilot Ec * AckChannelGain

Data Ec = Pilot Ec * DataChannelGain

En

erg

Pilot Ec

Ior

DRC Ec = Pilot Ec * DRCChannelGain

Ack Ec = Pilot Ec * AckChannelGain

Data Ec = Pilot Ec * DataChannelGain


2

DRCLength = 4 slots (default)DRCGating = nongated (default)DRCChannelGain = 3 dB (default)ACKChannelGain = 0 dB (default)DataChannelGain = DefaultGain + GainOffset (= 0 dB) + RateGain (= 0 dB)

The following figure shows a multipath signal from an AT along with the interference from other users.

Table 2-1: Reverse Channel Chips/Bit

Channel Chips/Bits

Data (9.6k) 128

Data (19.2k) 64

Data (38.4k) 32

Data (76.8k) 16

Data (153.6k) 8

ACK Channel 1024

DRC Channel 2048*DRCLength

Table 2-2: Default Data Channel Gain

Rate(kbps)DefaultGain

(dB)DefaultGain (linear)

9.6 3.75 2.4

19.2 6.75 4.7

38.4 9.75 9.4

76.8 13.25 21.1

153.6 18.50 70.8


2

Assuming default values and Ioc of -84 dBm (Typical value), the example calculations of Pilot Ec/Io and Data Eb/Nt for a 38.4kbps user for single and two-path cases are as follows:

Ior/Ec= 1 + 10^(3/10) + 10^(0/10)/2 + 10^(9.75/10) = 12.94Chips/Bit * ChannelGain/(Ior/Ec) = 32 * 10^(9.75/10) / 12.94 = 23.35

Single-Path (Îor = -96.3 dBm <- assumed for this example):

Pilot Ec/Io = 10*LOG(1 / (10^(-84/10) / 10^(96.3/10) + 1)/12.94) = -23.6 dB

Data Eb/Nt = 10*LOG(23.35 * (10^(96.3/10) / (10^(-84/10))) = 1.38 dB

Two-Path (Îor_1 = -96.3 dBm, Îor_2 = -99.3 dBm <- assumed for this example):

Pilot Ec/Io = 10*LOG(1 / (10^(-84/10) / 　　　　　　　　　　　(10^(96.3/10)+ 10^(99.3/10)) + 1)/12.94) = -22.0 dB

Data Eb/Nt = 10*LOG(23.35*((10^(-9.63)/(10^(-8.4)+10^(-9.93)) + (10^(-9.93)/(10^(-8.4)+ 10^(-9.63)))) = 2.98 dB

The following table shows minimum performance standard (MPS [4]) for a power-controlled AWGN link as well as measured values for Eb/Nt, at the location of the BTS antenna, required to support reverse rates at 1% PER:

Figure 2-5: Multipath Signal (Îor) with Interference from Other Users (Ioc)

Io c

Îo r

Th is A T

O the rA T s

P at h-1

P at h -2

P at h-3

Io c

Îo r

Th is A T

O the rA T s

P at h-1

P at h -2

P at h-3


2

The forward link is not power controlled, but the pilot remains the reference for estimating link interference. Therefore, interference on the forward link has no impact on capacity. Interference is only associated with location.

Equations used for calculation of key SNR values for the forward link are:Pilot Ec/Io = 1 / (Ioc/Îor + 1 ) [Eq 2-4]

Traffic Ec/Nt = Sum( Îor[i] / (Ioc + Sum( Îor[j, j!=i] ));for i-path signal (= Îor / Ioc ; for single-path case) [Eq 2-5]

Traffic Eb/Nt = Chips/Bit * Traffic Ec/Nt [Eq 2-6]

Where:Îor : Total energy of channel at receive antenna of ATIoc : Total energy of other interfering channels at receive antenna of ATIo : Total energy (signal + interference) at the receive antenna of AT = Îor + Ioc + NtChips/Bit = <see table>

Table 2-3: Reverse Eb/Nt Values

Rate(kbps) Measured Eb/Nt (dB) MPS Eb/Nt (dB)

9.6 0.15 1.34

19.2 0.14 1.26

38.4 -0.04 1.38

76.8 0.73 1.78

153.6 2.15 3.22

Table 2-4: Forward Channel Chips/Bit

Rate(kbps) Slots Chips/Bit

38.4 16 24

76.8 8 12

153.6 4 6

307.2 2 3

614.4 1 3/2

307.2 4 49/16

614.4 2 49/32

1228.8 1 3/4

921.6 2 49/48

1843.2 1 1/2

1228.8 2 49/64

2457.6 1 3/8


2

The following figure shows a multipath signal to an AT along with the interference from other sites.

Assuming default values and Ioc of -55.5 dBm (typical value), example calculations of Pilot Ec/Io, Traffic Eb/Nt and Ec/Nt for a 614.4kbps (2-slots) user under single and two-path cases are as follows:

Single-Path (Îor = -55 <- assumed for this example):

Pilot Ec/Io = 10*LOG(1 / (10^(-5.55)/10^(-5.5) + 1)) = -2.8 dBTraffic Ec/Nt = 10*LOG(10^(-5.5)/ 10^(-5.55)) = 0.5 dBTraffic Eb/Nt = 10*LOG(49/32 * (10^(-5.5)/ 10^(-5.55)) = 2.4 dB

Two-Path (Îor_1 = -55, Îor_2 = -60 <- assumed for this example):

Pilot Ec/Io = 10*LOG(1 / (10^(-5.55)/(10^(-5.5)+10^(-6)) + 1)) = -2.2 dBTraffic Ec/Nt = 10*LOG(10^(-5.5)/ (10^(-5.55)+ 10^(-6)) + 10^(-6)/ (10^(-5.55)+ 10^(-5.5))) = -0.02 dBTraffic Eb/Nt = 10*LOG(49/32 * 10^(-0.02/10)) = 1.8 dB

The following table shows estimated Ec/Nt values used by the AT to choose DRC values: (DRC rate is mapped if exceeding shown Ec/Nt value.)

Figure 2-6: Multipath Signal (Îor) with Interference from Other Sites (Ioc)

Io c

Îo r

Prim aryBT S

Othe rBT Ss

P at h -1

P at h-2

Pat h-3

Io c

Îo r

Prim aryBT S

Othe rBT Ss

P at h -1

P at h-2

Pat h-3


2

Table 2-5: Ec/Nt to DRC Mapping Example

DRC(kbps) Slots Ec/Nt (dB)

38.4 16 -12.5

76.8 8 -10.5

153.6 4 -7.4

307.2 2 -4.3

307.2 4 -4.2

614.4 2 -1.2

614.4 1 -1

921.6 2 1.5

1228.8 2 3.4

1228.8 1 3.7

1843.2 1 7.1

2457.6 1 9.1


2

2-5. What frequency channels(carriers) can be used for 1xEV-DO?

Information regarding frequency channels that are appropriate for 1xEV-DO usage can be found in the standard; and are the same as for cdma1X. Issues impacting the choice of which specific channels to use and the spacing between those channels are discussed in this section.

The higher rates used by 1xEV-DO can increase adjacent carrier interference (ACI). Estimates of C/I degradation show that the impact is reduced by not placing 1xEV-DO carriers adjacent to each other and by using wider carrier spacing. For 1.25 MHz channel spacing, performance is maximized by alternating 1xEV-DO and cdma1x carriers, rather than grouping 1xEV-DO carriers together. In cases where increasing the channel spacing is an option, 1.3MHz spacing will allow to maximize the performance improvements of our baseband filters.

To give the reader a feel for the C/I degradation, six carrier configuration examples (labeled A to F) are compared at 1.22 MHz, 1.25 MHz, and 1.30 MHz carrier spacing. The configurations examples and C/I degradation estimates are shown in Figure 2-7 and Figure 2-8.

Because 1xEV-DO will often be deployed in existing sites, frequency planning will be constrained by the existing carriers. To the extent possible however, we recommend the following measures be considered to maximize average sector throughput performance:

• Alternate 1x and DO carriers. The reduced power level of the 1x carriers

minimizes the amount of ACI.

• The operator should be aware that below 1.25 MHz channel spacing the ACI

contribution to the combined C/I increases rapidly (Note that Motorola’s filter design will achieve performance equivalent to, or better than, narrower filters down to channel spacing of approximately 1.22 MHz).

• Use channel spacings as wide as possible. At a channel spacing of 1.3 MHz

the effects of ACI are negligible and average sector throughput performance will be maximized (i.e., comparable to a single carrier with no adjacent carriers).

• Thoroughly understand the trade-offs involved with channel spacing and

carrier configuration on system capacity, as shown in Figure 2-8. While narrower channel spacing degrades performance, if the reduced spacing allows for an additional carrier this may be preferable even with the reduced throughput per carrier.


2

Figure 2-7: Representative Carrier Configurations


2

Figure 2-8: C/I for Different Carrier Configurations

10.00

11.00

12.00

13.00

14.00

15.00

16.00

17.00

18.00

Case A Case B Case C Case D Case E Case F

Carrier Configuration

BTS

C/I

(dB

)

1.231.251.3


2

Notes


2

Notes


2


Table of Contents

Chapter 3: What is the RF Coverage of 1xEV-DO?

Chap.3-1. Some General Comments on RF Coverage... .......................... 3-3

Chap.3-2. How do we estimate the RF coverage of the reverse link? .......... 3-6

Chap.3-3. How do we estimate the Forward Link Coverage ..................... 3-8

Chap.3-4. What is the Recommended Forward Link Power Setting? .............. 3-10




3-1. Some General Comments on RF Coverage...

3

The RF coverage of a site can be estimated by its RF link budget and an appropriate propagation model. The link budget makes assumptions about the transmitted power, the minimum acceptable receive power, and the losses and gains between the transmitter and receiver to estimate the maximum acceptable pathloss.

For the examples given in this section, reverse link carrier frequency is assumed to be 830 MHz, forward link carrier frequency is assumed to be 875 MHz, and BS antenna heights are assumed to be 30m (45m in rural areas). Appropriate Hata propagation formulas are used to determine the slope and the 1km intercept values.

The standard Hata propagation model is valid for frequencies between 150 and 1000 MHz. The COST 231 Hata propagation formulas can be utilized for frequencies between 1500 and 2000 MHz. The COST 231 Hata model is also utilized for approximating the distance for the deployments in the 2100 MHz area as well.

The standard Hata propagation formulas are valid for distances between 1 to 20 kilometers. For Hata model calculations that yield distances of less than 1 kilometer, the COST231-Walfish-Ikegami model is a reasonable statistical model to approximate the range. It requires some assumptions to be made regarding spacing of streets and buildings. The COST 231 Walfish-Ikegami model is valid for distances between 0.02 and 5 kilometers.

All of these models are well documented in literature on propagation models. Chapter 2 of the CDMA/CDMA2000 1X RF Planning Guide provides further information on the Hata and COST 231 Hata models.

For 800 MHz systems, the propagation calculations based on the Hata propagation model are as follows:

Propagation Slope = 44.9 - 6.55 * LOG(BS Ant Ht) [Eq 3-1]

Propagation Intercept (urban) = 69.55 + 26.16*LOG(Carr Freq) - 13.82*LOG(BS Ant Ht) - ((1.1*LOG(Carr Freq)-0.7)*(MS Ant Ht) -(1.56*LOG(Carr Freq)-0.8)) + (44.9 - 6.55*LOG(BS Ant Ht))*LOG(1)

Propagation Intercept (suburban) = 69.55 + 26.16*LOG(Carr Freq) - 13.82*LOG(BS Ant Ht) - ((1.1*LOG(Carr Freq)-0.7)*(MS Ant Ht) -(1.56*LOG(Carr Freq)-0.8)) + (44.9 - 6.55*LOG(BS Ant Ht))*LOG(1) -2*LOG(Carr Freq/28)^2-5.4

Propagation Intercept (rural) = 69.55 + 26.16*LOG(Carr Freq) - 13.82*LOG(BS Ant Ht) - ((1.1*LOG(Carr Freq)-0.7)*(MS Ant Ht) -(1.56*LOG(Carr Freq)-0.8)) + (44.9 - 6.55*LOG(BS Ant Ht))*LOG(1) -4.78*LOG(Carr Freq)^2+18.33*LOG(Carr Freq)-40.98 [Eqs 3-2]


3

For distances that are less than 1km, the propagation calculations based on the COST231-Walfish-Ikegami model are as follows:

Propagation Slope = 38.0 [Eq 3-3]

(Note: This slope assumes the BS antenna height is greater than the height of the buildings.)

Propagation Intercept (urban) = 32.4 + 20*LOG(1) + 20*LOG(Carr Freq) -16.9 - 10*LOG(Streetwidth) + 10*LOG(Carr Freq) + 20*LOG(Building Ht - MS Ant Ht) + 4 - 0.114*(90-55) - 18*LOG(1 + BS Ant Ht ? Building Ht) + 54 + 18*LOG(1) + (-4 + Environment Factor *(Carr Freq/925 -1)) *LOG(Carr Freq) - 9*LOG(Building Separation) [Eq 3-4]

where, Environment Factor = .7 (suburban); = 1.5 (urban)Streetwidth, Building Ht, MS Ant Ht, BS Ant Ht, and Building Separation are in meters.

Table 3-1: Example Hata Propagation Loss Slope and Intercept for Reverse Link:

REVERSE LINK

Frequency MHz 830 830 830

BS Antenna m 45 30 30

MS Antenna m 1.5 1.5 1.5

Slope dB/dec 34.071 35.225 35.225

1km LossIntercept

rural 94.849

urban 125.4866

suburb 115.7535

Table 3-2: Example Hata Propagation Loss Slope and Intercept for Forward Link:

FORWARD LINK

Frequency MHz 875 875 875

BS Antenna m 45 30 30

MS Antenna m 1.5 1.5 1.5

Slope dB/dec 34.071 35.225 35.225

1km LossIntercept

rural 95.225

urban 126.0843

suburb 116.2152


3

For 2GHz systems, the impact of the higher frequency may result in more cases where the COST-231 Hata model will result in radii less than 1 km. For these cases, the COST231 Walfish-Ikegami may be a more appropriate model to estimate the range of a site.

Fading margin values are calculated by finding the value that satisfies Jakes' equations for 90% cell coverage reliability (or the cell coverage reliability level desired).

The reliability calculations (Jakes' Equations) for the slope estimates are as follows:

Cell Edge Reliability = 0.5*(1+ERF(0,alpha)) [Eq 3-5]

Percent Cell Coverage = 0.5*(1+ERF(0,alpha)+EXP((1+2*alpha*beta)/beta^2) *(1-ERF(0,(alpha*beta+1)/beta))) [Eq 3-6]

where:alpha = Fading Margin/(Lognormal Standard Deviation*SQRT(2))

beta = Propagation Slope*LOG(EXP(1))/(Lognormal Standard Deviation*SQRT(2))

Table 3-3: Example Coverage Reliability for Slopes Obtained Previously:

Fading Margin 6.4 6.5

Propagation Slope 35.2 34.1

Lognormal Std Dev 8.9 8.9

Cell Edge Reliability 0.76 0.77

Percent Cell Coverage 0.90 0.90

a= 0.5098371 0.51493544

b= 1.215426 1.17562828


3

3-2. How do we estimate the RF coverage of the reverse link?

The following equations were used for calculating reverse link budget pathloss values:

RX Sensitivity (dBm) = Thermal Noise + Bandwidth + Eb/No + Noise Figure - Processing Gain + Noise Rise [Eq 3-7]

Pathloss (dB) = TX Power - TX Equip. Loss + TX Antenna Gain - Penetration Loss + RX Antenna Gain - RX Equip. Loss - Fading Margin - RX Sensitivity + Handoff Gain [Eq 3-8]

The pathloss value is then entered into the appropriate propagation model to arrive at an estimated reverse link coverage distance.

Distance (km) = 10^( (Pathloss ? Propagation Intercept) / Propagation Slope ) [Eq 3-9]

The following tables provide examples for parameter values that are used to calculate the pathloss for the 1xEV-DO reverse link. The required Eb/No is assumed to be the same as values previously used for 1X RC3 link budget estimations.

Table 3-4: 1xEV-DO Reverse RF Link Budget

Item Units Value Value Value alue Value

BandwidthHz 1228800 1228800 1228800 1228800 1228800

dB - Hz 60.9 60.9 60.9 60.9 60.9

Data Rate bps 9600 19200 38400 76800 153600

Processing Gain dB 21.1 18.1 15.1 12.0 9.0

TX PowerWatts 0.2 0.2 0.2 0.2 0.2

dBm 23 23 23 23 23

TX Equip. Loss dB 0 0 0 0 0

TX Antenna Gn dB 0 0 0 0 0

RX Antenna Gn dB 16 16 16 16 16

RX Equip. Loss dB 3.3 3.3 3.3 3.3 3.3

Handoff Gain dB 3.5 3.5 3.5 3.5 3.5

Thermal Noise dBm/Hz -174 -174 -174 -174 -174

RX Noise Figure dB 6 6 6 6 6

Noise Rise Margin dB 6 6 6 6 6

Required Eb/No dB 5.6 3.5 3 2.5 2.1

Fading Margin dB 6.5 6.5 6.5 6.5 6.5

RX Sensitivity dBm -116.6 -115.7 -113.2 -110.6 -108.0


3

The pathloss and distance estimates for various environments are shown below. The penetration loss for in-vehicle is assumed here to be 8 dB, while in-building loss is assumed to change (from 8 dB in the Rural environment to 15 dB in the Urban environment) based upon the propagation environment.

Table 3-5: Pathloss for Urban area w/ antenna height of 30 m (Top: In-vehicle, Bottom: In-building)

Data Rate kbps 9.6 19.2 38.4 76.8 153.6

Penetration Loss dB 8 8 8 8 8

Max Pathloss dB 141.3 140.4 137.9 135.4 132.7

Max Distance km 2.8 2.6 2.2 1.9 1.6


Max Pathloss dB 134.3 133.4 130.9 128.4 125.7

Max Distance km 1.8 1.7 1.4 1.2 1.0

Table 3-6: Pathloss for Suburban area w/ antenna height of 30 m (Top: In-vehicle, Bottom: In-building)

Data Rate kbps 9.6 19.2 38.4 76.8 153.6


Max Pathloss dB 141.3 140.4 137.9 135.4 132.7

Max Distance km 5.3 5.0 4.2 3.6 3.0


Max Pathloss dB 139.3 138.4 135.9 133.4 130.7

Max Distance km 4.7 4.4 3.7 3.2 2.7

Table 3-7: Pathloss for Open Rural area w/ antenna height of 45 m (Top: In-vehicle, Bottom: In-building)

Data Rate kbps 9.6 19.2 38.4 76.8 153.6


Max Pathloss dB 141.3 140.4 137.9 135.4 132.7

Max Distance km 23.1 21.7 18.3 15.4 12.9


Max Pathloss dB 141.3 140.4 137.9 135.4 132.7

Max Distance km 23.1 21.7 18.3 15.4 12.9


3

3-3. How do we estimate the Forward Link Coverage

The following equations were used for calculating forward link budget values:

RX Sensitivity (dBm) = Thermal Noise + Bandwidth + Ec/Nt + Noise Figure [Eq 3-10]

Pathloss (dB) = TX Power - TX Equip. Loss + TX Antenna Gn - Penetration Loss + RX Antenna Gn - RX Equip. Loss - Fading Margin - RX Sensitivity [Eq 3-11]

Below is the forward link pathloss calculation using required Ec/Nt values estimated by Motorola.

Table 3-8: 1xEV-DO Forward RF Link Budget

Item Units Value Value Value Value Value Value Value Value Value

BandwidthHz 1228800 1228800 1228800 1228800 1228800 1228800 1228800 1228800 1228800

dB-Hz 60.9 60.9 60.9 60.9 60.9 60.9 60.9 60.9 60.9

Data Rate bps 38400 76800 153600 307200 614400 921600 1228800 1843200 2457600

Modulation PSK 4 4 4 4 4 8 4, 16 8 16

TX PowerWatts 15 15 15 15 15 15 15 15 15

dBm 41.8 41.8 41.8 41.8 41.8 41.8 41.8 41.8 41.8

TX Equip. Loss dB 3.3 3.3 3.3 3.3 3.3 3.3 3.3 3.3 3.3

TX Antenna Gn dB 16 16 16 16 16 16 16 16 16

RX Antenna Gn dB 0 0 0 0 0 0 0 0 0

RX Equip. Loss dB 0 0 0 0 0 0 0 0 0

Thermal Noise dBm/Hz -174 -174 -174 -174 -174 -174 -174 -174 -174

RX Noise Figure dB 10 10 10 10 10 10 10 10 10

Required Ec/Nt dB -13.1 -10.5 -7.4 -4.3 -1.2 1.5 3.4 7.1 9.1

Fading Margin dB 6.5 6.5 6.5 6.5 6.5 6.5 6.5 6.5 6.5

RX Sensitivity dBm -116.2 -113.6 -110.5 -107.4 -104.3 -101.6 -99.7 -96.0 -94.0


3

The pathloss and distance estimates for various environments are shown below. The penetration loss values are the same as assumed for the reverse link.

Table 3-9: Pathloss for Urban area w/ antenna height of 30 m (Top: In-vehicle, Bottom: In-building)

Data Rate kbps 38.4 76.8 153.6 307.2 614.4 921.6 1228.8 1843.2 2457.6

Penetration Loss

dB 8 8 8 8 8 8 8 8 8

Max Pathloss dB 156.2 153.6 150.5 147.4 144.3 141.6 139.7 136.0 134.0

Max Distance km 7.1 6.0 4.9 4.0 3.3 2.8 2.4 1.9 1.7

Penetration Loss

dB 15 15 15 15 15 15 15 15 15

Max Pathloss dB 149.2 146.6 143.5 140.4 137.3 134.6 132.7 129.0 127.0

Max Distance km 4.5 3.8 3.1 2.5 2.1 1.7 1.5 1.2 1.1

Table 3-10: Pathloss for Suburban area w/ antenna height of 30 m (Top: In-vehicle, Bottom: In-building)

Data Rate kbps 38.4 76.8 153.6 307.2 614.4 921.6 1228.8 1843.2 2457.6

Penetration Loss

dB 8 8 8 8 8 8 8 8 8

Max Pathloss dB 156.2 153.6 150.5 147.4 144.3 141.6 139.7 136.0 134.0

Max Distance km 13.6 11.5 9.4 7.7 6.3 5.2 4.6 3.6 3.2

Penetration Loss

dB 10 10 10 10 10 10 10 10 10

Max Pathloss dB 154.2 151.6 148.5 145.4 142.3 139.6 137.7 134.0 132.0

Max Distance km 11.9 10.1 8.2 6.7 5.5 4.6 4.1 3.2 2.8

Table 3-11: Pathloss for Open Rural area w/ antenna height of 45 m (Top: In-vehicle, Bottom: In-building)

Data Rate kbps 38.4 76.8 153.6 307.2 614.4 921.6 1228.8 1843.2 2457.6

Penetration Loss

dB 8 8 8 8 8 8 8 8 8

Max Pathloss dB 156.2 153.6 150.5 147.4 144.3 141.6 139.7 136.0 134.0

Max Distance km 61.4 51.5 41.8 33.9 27.5 22.9 20.1 15.7 13.7

Penetration Loss

dB 8 8 8 8 8 8 8 8 8

Max Pathloss dB 156.2 153.6 150.5 147.4 144.3 141.6 139.7 136.0 134.0

Max Distance km 61.4 51.5 41.8 33.9 27.5 22.9 20.1 15.7 13.7


3

3-4. What is the Recommended Forward Link Power Setting?

The reverse link is limited to a max power of 200 mW. Balancing the pathloss for the highest rates of both links (Rvs = 153.6 kbps; Fwd = 2.4 Mbps), it is found that 15 watts should be sufficient on the forward link. At 15 W, an in-building user which is able to obtain a max rate of 9.6 kbps on the reverse link should be able to obtain around 1.2 Mbps on the forward link, C/I conditions permitting. It is recommended to set 15 watts for all sites uniformly. This setting also allows room for minor up or down adjustments of the power.


3

Notes


3


Table of Contents

Chapter 4: What is the RF Capacity of 1xEV-DO?

Chap.4-1. How do we estimate the Reverse Link Capacity of 1xEV-DO? ......... 4-3

Chap.4-2. What is the Forward Link Capacity? ............................... 4-8




4-1. How do we estimate the Reverse Link Capacity of 1xEV-DO?

4

The goal is to find the maximum number of links best-served by a sector. This is designated by ‘N’ in the figure below. The total number of links served by the sector is ‘C’, and this includes both the best-served links ‘N’ as well as the links best-served by another sector. The number of links best-served by another sector can be thought of as a percentage ‘f’ of the links by the sector in which the ‘N’ users are located. The total number of links attached to the sector, therefore, is:

C = N*(1+f) [Eq 4-1]

Now, let’s look at the total power ‘Io’ being received at the sector. All links are assumed to be received at approximately the same power ‘S’ due to power control. Therefore, the total power received from all users is then C*S. The total power received from all users ‘C*S’ plus thermal noise power ‘NoW’ is the total power received at the sector, as illustrated in the following figure.

Io = NoW + N*(1+f)*S [Eq 4-2]

Figure 4-1: Link Capacity


4

Solving for the number of best-served links, we get the following equation.

N = (Io - NoW) / ((1+f)*S) = 1 / ((1+f)*SIR) [Eq 4-3]

Where,

SIR = S / (Io - NoW) [Eq 4-4]

SIR is the Signal-to-Interference Ratio. Note that 1/SIR is the number of total links served by the cell; 1/(1+f) is the percentage of links best served by the cell; and, f/(1+f) is the percentage best served by another cell.

1/SIR = (Io - NoW) / S = N*(1+f)*S / S = N*(1+f) = C [Eq 4-5]

We can also define the Signal-to-Interference-plus-Noise Ratio (SINR) as follows.

SINR = S / Io [Eq 4-6]

Note that when

Io >> NoW,

then

(Io - NoW) -> Io

Therefore,

Figure 4-2: Power Capacity


4

SIR -> SINR& N -> 1 / ((1+f)*SINR) [Eq 4-7]

(Note: Actually SIR and SINR should have S subtracted from the denominator, but that only changes the final capacity estimate by at most 1 link. We can eliminate the term from the intermediate calculations for simplification, and add in one to the final estimate.)

Therefore, if we know the percentage of links that come from neighboring cells ‘f’, and if we have an estimate of the lowest acceptable (or required) SINR for good performance, then we can estimate the maximum capacity, N. The above graph shows the minimum required and achieved SINR. (SINR values come from either simulation or field data.) The maximum number of links is estimated by solving equation 4-7 for N.

For the given SINR and f

SINRreq = 0.0222 (= -16.5dB)f = 45%

we can estimate the maximum capacity (best-served links) as

N = 1/(0.222*1.45) = 31 links

The total number of links, including SHO links is

C = 1 / 0.222 = 45 links

Figure 4-3: Number of Users Versus SINR


4

We can improve our estimate by looking at the noise rise over thermal noise ‘Z’.

Z = Io / NoW [Eq 4-8]

Note that when

Io = NoW,

Then

Z = 1.

And when

Io >> NoW, (or Io -> ∞ )

Then

Z -> ∞ .

We can define a loading factor ‘Y’ which converts Z, which varies from 1 to infinity, to a variable that varies between zero and one.

Y = (Z - 1) / Z [Eq 4-9]

Such that when

Io = NoW,

Then

Y = 0%. no load)

And when

Io >> NoW, ( (Z-1) -> Z )

Then

Y -> 100%. (max load)

We can expand out the load factor ‘Y’ to make it a function of the number of users ‘N’.

Y = (Z-1)/Z = (Io/NoW ? 1) / (Io/NoW) = (Io - NoW) / Io = N*(1+f)*S / (NoW+N*(1+f)*S) = N*(1+f)*S / Io [Eq 4-10]

Then, we solve for the number of links.

N = (Y * Io) / (S*(1+f)) = Y / (SINRreq*(1+f)) [Eq 4-11]

When Y = 1 (i.e., full load), then N is at the maximum value. This is the same as we found in Equation 4-7.

N = 1 / (SINRreq*(1+f))


4

However, in reality, Y cannot equal 1. Because if Y is 1, then Z is ∞ ; and, if Z is ∞ , then Io is ∞ . And if Io is ∞ , then S is ∞ ; which can’t be so because there is a limit on power.

Typically, we assume that Io is allowed to go 6 to 10 dB or so above NoW. This results in a Y of 75% to 90%.

N = 75%~90% * 1/(SINRreq*(1+f)) [Eq 4-12]

The following graph shows the relation ship between the loading factor ‘Y’ and noise rise ‘Z’. When the noise rise starts to increase rapidly, we can expect a the link performance to decrease. We can therefore estimate the maximum capacity to be somewhere just below this turn in the graph.

The capacities for various data rates have been estimated for various reverse link data rates in the below table.

Figure 4-4: Loading Factor Versus Noise Rise

Table 4-1: Capacity Estimates for Reverse Link

Rate [kbps] 9.6 19.2 38.4 76.8 153.6

Cwll Interference (f) 0.45 0.45 0.45 0.45 0.45

SINR required [db] -16.55 -15.88 -13.06 -10.25 -8.44

SINR required [linear] 0.0222 0.0258 0.0494 0.0943 0.1432

Pole Capacity [links] 31.1 26.7 14.0 7.3 4.8

Max Capacity [links] 24.9 21.4 11.2 5.9 3.9


4

4-2. What is the Forward Link Capacity?

The reverse link is assumed to be the limit for the capacity of the 1xEV-DO system. Will there be any cases where the forward link becomes the limiting factor? Not likely. The forward link should be limited, not by power, but by the availability of MAC channels. Since the reverse link is also using the same number for MAC channels however, both links would become limited at the same time.


4

Notes


4


Table of Contents

Chapter 5: What is the Throughput of 1xEV-DO?

Chap.5-1. What scheduling algorithms exist for 1xEV-DO(Forward Link)? ...... 5-3

Chap.5-2. Some discussion on 1xEV-DO forward link throughput ............... 5-4

Chap.5-3. How to estimate forward link throughput for 1xEV-DO? ............. 5-8

Chap.5-4. What Limitations exist for Forward-Link Throughput? .............. 5-8

Chap.5-5. How reverse link data rate control works for 1xEV-DO? ............ 5-9




5-1. What scheduling algorithms exist for 1xEV-DO(Forward Link)?

5

There are two forward link scheduling algorithms available: Round Robin and Proportional Fairness. Round Robin simply assigns each waiting user in turn based on that user's current DRC request. Proportional Fairness considers each users average requested rate and compares to the current request rate, assigning a turn the user with the highest current to average ratio. Because Proportional Fairness will achieve a higher sector throughput than Round Robin, while end-user throughput is about the same, Proportional Fairness is the recommended default.

The simple example illustrated in Table 5-1 shows which of 3 similar users would be assigned in a timeslot under the 2 different algorithms. Note that the Round Robin method assigns each user in turn, while the Proportional Fairness method assigns the user with the highest "DRC/Average" ratio.

The average value is calculated as follows:

Average_DRC (Slot n) = Average_DRC (Slot n-1) * (tc-1)/tc + DRC/tc [Eq 6-1]

Where, tc : the number slots that DRC is averaged over; default = 1000

Table 5-1: Scheduling Algorithm Comparison

　　 1 2 3 4 5 6 7 8 9 Average

User 1

DRC 307.2 614.4 307.2 307.2 614.4 307.2 307.2 307.2 153.6 370.5

Average 359.3 359.3 359.5 359.5 359.4 359.7 359.6 359.6 359.5 　

DRC/Avg 0.85 1.66 0.83 0.83 1.66 0.83 0.83 0.83 0.41 　

User 2

DRC 153.6 307.2 153.6 614.4 307.2 153.6 307.2 307.2 614.4 248.4

Average 358.3 358.1 358.0 357.8 358.1 358.0 357.8 357.8 357.7 　

DRC/Avg 0.43 1.24 0.62 2.47 1.24 0.62 1.24 1.24 2.47 　

User 3

DRC 307.2 307.2 614.4 153.6 307.2 614.4 614.4 153.6 307.2 582.5

Average 358.2 358.1 358.1 358.3 358.1 358.1 358.3 358.6 358.4 　

DRC/Avg 0.86 0.53 1.05 0.26 0.53 1.05 1.05 0.26 0.53 　

Prop Fair

User 3 1 3 2 1 3 2 2 2 　

Rate 307.2 614.4 614.4 614.4 614.4 614.4 307.2 307.2 614.4 512.0

Rnd Rbn

User 1 2 3 1 2 3 1 2 3 　

Rate 307.2 307.2 614.4 307.2 307.2 614.4 307.2 307.2 307.2 375.5

Figure 5-1: DRC versus Time

EXAMPLE

User 2 User 1

User 3 Time Slots


5

5-2. Some discussion on 1xEV-DO forward link throughput

There are actually only 4 slot rates on the forward link: 614.4, 1228.8, 1843.2, and 2457.6. The rates shown in the standard (DRC rates) are sector throughput rates achieved by repeating the data of some of the base rates, to ensure that data is properly received under poor RF conditions. Since this data is repeated, it is possible to receive the data correctly before all the repeated slots are sent. In this case, an ACK on the reverse link will allow early termination. Considering this early repetition, the possible 1xEV-DO packet rates for users are listed in the below table.

Table 5-2: Table 20: Effective Rates for Forward Link

Modulation Base Rate Slots Effective Rate

QPSK 614.4 16 38.4

QPSK 614.4 15 41.0

QPSK 614.4 14 43.9

QPSK 614.4 13 47.3

QPSK 614.4 12 51.2

QPSK 614.4 11 55.9

QPSK 614.4 10 61.4

QPSK 614.4 9 68.3

QPSK 614.4 8 76.8

QPSK 614.4 7 87.8

QPSK 614.4 6 102.4

QPSK 614.4 5 122.9

QPSK 614.4 4 153.6

QPSK 614.4 3 204.8

QPSK 614.4 2 307.2

QPSK 614.4 1 614.4

QPSK 1228.8 4 307.2

QPSK 1228.8 3 409.6

QPSK 1228.8 2 614.4

QPSK 1228.8 1 1228.8

8PSK 1843.2 2 921.6

8PSK 1843.2 1 1843.2

16QAM 2457.6 2 1228.8

16QAM.6 2457.6 1 2457.6


5

Throughput can be considered from various points in the system, each point having a different value. From a sector point of view, there is a slot of data every 1.67 msec, and the throughput is the average data rate of each of those slots. From a mobile point of view, there is a file being downloaded, and the throughput is the amount of time it takes to download a given amount of data.

From the sector's point of view, it is sending data every slot, even though those slots are destined for different users. Of course this assumes a fully loaded system. When a sector is not heavily loaded and there are periods when there is no data to request or send, the traffic portion of the slot is idle (i.e., gated off). The gating of the traffic portion should not have much impact upon the DRC request, because DRC rates are dependent on only the Pilot portion of the slot. Since the pilot and traffic portions of a slot are separated by the MAC portion by several chips, even far away sites should not have much impact on Pilot-based C/I. Where the impact will be is in throughput, as low load systems will have lower C/I values of the traffic portion of the slot than the reference Pilot C/I, allowing for more early ACKs.

Figure 5-2: Multiple User Data

-- User 1-- User 2-- User 3

-- User 1-- User 2-- User 3


5

From a single user's point of view, it is not receiving data every slot. Also, the data rate can vary in each received slot.

The rates discussed so far are RF physical layer rates. They contain overhead. Since there are multiple layers (much like an onion) each containing overhead, each layer can be peeled off to find the rate at that layer. Depending on the layer being measured, the throughput will be different. Overhead taken out at each layer results in the throughput seen at the FTP level differing from the air throughput. This image shows how a 4096 bit physical layer packet is related to other layers.

Figure 5-3: Single User Data

-- 614.4 kbps-- 1843.2 kbps-- 2457.6 kbps

-- 614.4 kbps-- 1843.2 kbps-- 2457.6 kbps

Figure 5-4: Overhead Bits at Each Layer

P H Y S

M A C

S TR

R L P

P P P

M T U

4 008 + 88 b its

1000 + 2 b its

998 + 2 b its

9 76 + 2 2 bits

1 200 0 + 1 6 b its

1 196 8 + 3 2 b itsIn te rn et P ro to cols

… ..… ..

P H Y S

M A C

S TR

R L P

P P P

M T U

4 008 + 88 b its

1000 + 2 b its

998 + 2 b its

9 76 + 2 2 bits

1 200 0 + 1 6 b its

1 196 8 + 3 2 b itsIn te rn et P ro to cols

… ..… ..


5

The following table shows some sample estimates for rates at different layers. The second RLP rate takes in account slots not available due to control channel usage and data re-sent due to packet error (assumed here to be 5%). The first RLP rate and the FTP rate are obtained by removing packet headers.

Table 5-3: Data Rates at Various Layers

Air Rate 38.4 76.8 153.6 307.2 614.4 921.6 1228.8 1843.2 2457.6

RLP Rate (1) 36.60 73.20 146.40 292.80 585.60 878.40 1171.20 1756.80 2342.40

RLP Rate (2) 31.19 62.39 124.77 249.55 499.09 748.64 998.18 1497.27 1996.36

FTP Rate 31.07 62.14 124.27 248.55 497.10 745.65 994.19 1491.29 1988.39


5

5-3. How to estimate forward link throughput for 1xEV-DO?

The effective throughput from the perspective of particular user can be estimated as follows:

End-User Throughput(k) = 1/N * R(k) [Eq 6-2]Sector Throughput = Sum[ End-User Throughput(k) ] [Eq 6-3]

where,

N : total number of usersR(k) : data rate for user 'k'.

Let's assume an example with three users:

N = 3 usersR(1) = R(2) = 153.6 kbps; R(3) = 1843.2 kbpsEnd-User Throughput(1) = End-User Throughput(2) = 153.6 / 3 = 51.2 kbpsEnd-User Throughput(3) = 1843.2 / 3 = 614.4 kbpsSector Throughput = 2*51.2 + 614.4 = 716.8 kbps

The difference between Round Robin and Proportional Fairness will be in the variable R(k). Round Robin tends to assign users at their average rates, but proportional fairness tends to assign users at higher than average rates, especially as the number of users increases.

5-4. What Limitations exist for Forward-Link Throughput?

When using Proportional Fairness, the max sector throughput increases with the number of users (assuming all users are in similar C/I environment) up to the max data rate capable in that environment. The end-user sector throughput decreases and the average value is sector throughout divided by the number of users. The change in sector and end-user throughput is shown in the graphs below.

Figure 5-5: Sector and End-User Throughput


5

5-5. How reverse link data rate control works for 1xEV-DO?

The access terminal shall select a transmission rate that satisfies the following constraints:

1. PayloadRate DeterminationThe access terminal shall not select a data rate for which the minimum payload length is greater than the size of data it has to send.

2. MaxRate DeterminationThe access terminal shall transmit at a rate that is no greater than the value of MaxRate.

3. CurrentRateLimit DeterminationThe access terminal shall transmit at a rate that is no greater than the value of CurrentRateLimit.

4. MaxPwrCapableRate DeterminationThe access terminal shall transmit at a data rate no higher than the highest data rate that can be accommodated by the available transmit power.

The reverse traffic channel rate is determined as follows:

Reverse Traffic Channel Rate = MIN { MaxRate, CurrentRateLimit, MaxPwrCapableRate, PayloadRate } [Eq 6-4]

Rate distribution and rate choice will both depend on the following: Transition Probabilities (MaxRate method), Max/Min Rate Limits (CurrentRateLimit method), the user call model, and the number and distribution of the users.

Additional explanation on the four different determination methods is provided next.


5

PayloadRate Determination

• Based on Payload Size (Security Layer packet)

• Frequency : Every frame (16 slots)

Table 5-4: Size of Reverse Link Payload

Transmission Rate(kbps) Minimum Payload(bits) Maximum Payload(bits)

0 0 0

9.6 1 232

19.2 233 488

38.4 489 1000

76.8 1001 2024

153.6 2025 4072


5

MaxRate Determination

• Determined by current rate and Reverse Activity bit (sent by RA Channel)

• Frequency : Every slot

Figure 5-6: MaxRate Determination

Current Rate(kbps)

CombinedBusyBit ConditionMaxRateTrue

(kbps)MaxRateFalse

(kbps)0 0 TRUE 9.6 N/A

9.6 0 x < Transition009k6_019k2 19.2 9.619.2 0 x < Transition019k2_038k4 38.4 19.238.4 0 x < Transition038k4_076k8 76.8 38.476.8 0 x < Transition076k8_153k6 153.6 76.8153.6 0 FALSE N/A 153.6

0 1 FALSE N/A 9.69.6 1 FALSE N/A 9.619.2 1 x < Transition019k2_009k6 9.6 19.238.4 1 x < Transition038k4_019k2 19.2 38.476.8 1 x < Transition076k8_038k4 38.4 76.8153.6 1 x < Transition153k6_076k8 76.8 153.6

ReverseActivity bit determination from active set sector.

(see below...)

Current Transmission Rate Random Number "x"

CombinedBusyBit

The AT sets a MaxRate valuebased on: * Current Transmission Rate * CombinedBusyBit (RA bit) * Random Number "x"

The AT generate a uniformlydistributed random number "x"

0 < x < 1

Determination of the MaxRate

ReverseActivity bit DeterminationEach sector makes a decision on RA_bit based on Reverse Noise Rise and Reverse Sector Throughput information.

#1_RA_bit = 0 && #2_RA_bit = 0 -> RA_bit = 0#1_RA_bit = 1 || #2_RA_bit = 1 -> RA_bit = 1

AT receives RA_bit information from reverse SHO links, and determine the CombinedBusyBit

RA_bit of all reverse SHO links = 0 -> CombinedBusyBit = 0RA_bit of all reverse SHO links != 0 -> CombinedBusyBit = 1

#1. Reverse Noise Rise - based

#2. Reverse Sector Throughput - based

RA bit = 0

RA bit = 1

Rev. Sector Tput

ThroughputThresholdValue-forRAB

Time

RABLength

RA bit = 0

RA bit = 1

Rev. Noise Rise

RNRThresholdValue-forRAB

Time

RABLength

Table 7.7.1 Default Value for ConditionsField Defalt Defalt/255（Decimal）

Transition009k6_019k2 0x30 0.188235294Transition019k2_038k4 0x10 0.062745098Transition038k4_076k8 0x08 0.031372549Transition076k8_153k6 0x08 0.031372549Transition019k2_09k6 0x10 0.062745098Transition038k4_019k2 0x10 0.062745098Transition076k8_038k4 0x20 0.125490196Transition153.k6_076k8 0xFF 1


5

CurrentRateLimit Determination

• Set by BroadcastReverseRateLimit message sent from system (Control

Channel)• Frequency : RRLcycle (default = 6 CCcycle * 16 frames),

(where, CCcycle = Control Channel Cycle)

Figure 5-7: CurrentRateLimit Determination

The AT maintains a CurrentRateLimit value(initially set to 153.6kbps)

The RateLimit values based on the number of connections

- Mode A < RRLUserLowerths - RRLUserLowerths <= Mode B <= RRLUserUpperths - RRLUserUpperths < Mode C

Mode A

Mode B

Mode C

RateLimit =RRLRateUpperlimit

RateLimit =RRLRateLowerlimit

The RateLimit valuebased on the Reverse

Link throughput : X

However, the region of the RateLimit value that changes is basedupon the following condition:

RRLRateLowerlimit <= RateLimit <= RRLRateUpperlimit

Number of connections

Mode B

Mode A

Mode C

RRLUserUpperths

RRLUserLowerths

Mode Relation Diagram

RateLimit<=

CurrentRateLimit

RateLimit → CurrentRateLimit(Immediately)

Yes

No

RateLimit → CurrentRateLimit(After 16 slots)

RevLinkTput(kbps)

RateLimit(kbps)

X ? 6.4 9.66.4 < X ? 16.0 19.216.0 < X ? 32.0 38.432.0 < X ? 64.0 76.8

64.0 < X 153.6

The RateLimit is updated by aBroadcastReverseRateLimit message sent from the AN


5

MaxPwrCapableRate Determination

• Based on required power estimate - MaxCapablePowerRate is the highest

rate that can be accommodated by available transmit power• Frequency : = 600 * ( 1 - 1/DRCLockPeriod ) [bps] : DRCLockPeriod = 8 or

16 slots

Figure 5-8: MaxPwrCapableRate Determination

MaxPwrCapableRate

Reverse Power Control

Estimate MaxPwrCapableRate :Tot_Pwr (Rev_Pilot+Data+DRC+Ack)

<= MS_Max_Tx_Pwr

Yes

No CurrentMaxPwrCapableRate

= 9.6kbps ?

No

Yes

DRC channelGating off

Ack channelGating off

No Data Channel

Pilot

ACK

DRC

Data

Data Rate is reduced

ACK, DRC gating off

MS_Max_Tx_Pwr = 23dBm

Time

MobileTx Power

Assume the DataCH rate:153.6 kbps

|9.6 kbps

Next lower rate


5

Notes


Table of Contents

Chapter 6: What other things to consider for RF planning?

Chap.6-1. What are the key error rate metrics used for 1xEV-DO? ............ 6-3

Chap.6-2. What tools are there for more detailed RF planning analysis? ..... 6-3




6-1. What are the key error rate metrics used for 1xEV-DO?

6

The TAS [3] and MPS [4,5] standards provide details on the formulas and procedures for calculating error rate metrics. Shown below are the key metrics shown in the MPS [4,5] standards. Refer to the TAS [3] standard for details on each of the calculation parameters.

Reverse Link Error Rates Measurements:

Traffic Channel PER[rate_i] = Packet Errors[rate_i] / Packets Transmitted[rate_i]DRC SER = DRC Errors / Symbols TransmittedDRC Miss Rate = (DRC Cover Errors + DRC Erasures) / Symbols Transmitted

Forward Link Error Rates Measurements:

Control Channel PER = 1 - (ControlChannelPktCount / (IdleStateElapseTime/256))Traffic Channel PER[rate_i] = Bad Packets[rate_i] / Transmitted Packets[rate_i]Average Traffic Channel PER = Sum[Bad Packets[rate_i]; each rate_i] / Sum[Transmitted Packets[rate_i]; each rate_i]Forward Traffic Channel Throughput = (Good MAC Layer Packets * 1024) / Test Time

6-2. What tools are there for more detailed RF planning analysis?

Motorola has an RF system simulation tool (NetPlan) that supports 1xEV-DO. Please refer to the NetPlan documentation for details about what NetPlan can do for RF system planning needs.


6

Notes


Documents

EVDO RF Planning Guide