3g Rf Tuning Training

RF Tuning Workshop

Agenda • • • •

Introduction Basic Principles RF Initial Tuning Overview Case Study

Introduction WCDMA Network Initial Tuning is aimed to make the network to be ready for launch in term of Accessibility, Retainability, and Integrity.

Basic Principles

Basic Principles • WCDMA General Priniciple • Ericsson WCDMA RAN Functionality

WCDMA General Principle

Spectrum Allocation

1850

1900

1950

2000

2050

2100

2150

2200

2250

2010 MHz

ITUAllocations 1885 MHz

Europe

2025 MHz

UMTS

GSM1800 DECT

MSS

1850 MHz WLL

UMTS

MSS 2170 MHz

WLL

IMT 2000

GSM1800

MSS

2170 MHz

2110 MHz

1980 MHz

1880 MHz

China

IMT 2000

MSS

IMT 2000

1885 MHz

MSS

IMT 2000

MSS

IMT 2000

MSS

1980 MHz

1885 MHz 1918 MHz

Japan Korea (w/o PHS)

PHS

IMT 2000

MSS

1895 MHz

North America

2160 MHz

PCS AA D B

1850

EF C

1900

AA D B

1950

EF C

M Reserve D MSS S

MSS

2000

2050

2100

2150

2200

2250

UMTS Spectrum Frequency Division Duplex; 2x60 MHz UTRA Paired Band: WCDMA Uplink: 1920-1980 MHz Downlink: 2110-2170 MHz

TDD 1900

FDD UL 1950

MSS TDD 2000

Time Division Duplex UTRA Unpaired Band: UTRA TDD & TD-SCDMA 1900-1920 MHz and 2010-2025 MHz

FDD DL 2050

2100

2150

MSS 2200

f MHz

Mobile Satellite Service; 2x30 MHz

Uplink: 1980-2010 MHz Downlink: 2170-2200 MHz

Direct Sequence CDMA • Separate users through different codes

• IS-95 (1.25 MHz)

• Large bandwidth

• CDMA2000 (3.75 Hz)

• Continuous transmission and reception

t MS 1 MS 2 MS 3

Code

f 5 MHz

• WCDMA (5 MHz)

Coding Concept User Information bits are multiplied with the quasi random bits called chips causing the information to be spread over a wide bandwidth Orthogonal Code 1

Orthogonal Codes provide unique identification of each data channel

Sync. Bits

Orthogonal Code 2

Control/ Signaling Data

Spread Spectrum (PN) Codes provide unique identification of each transmitter

Error Error Protection Protection

Spread Spectrum (PN or Gold) Code

Orthogonal Code 3

Vocoder Vocoder

Error Error Protection Protection

Linear Linear Summation Summation Orthogonal Code 4

User Data Channel 1

Filtering Filtering ++ RF RF Modulation Modulation

RF Out

Error Error Protection Protection Orthogonal Code N

User 1 User 2 User 3

User Data Channel N

Error Error Protection Protection

... Frequency

Orthogonal Code Orthogonal Code • Known as Channelization Code • The output is a stream of bits, which is called Chip • Chip Rate for WCDMA is 3.84 Mbps • Used to differentiate data channels within the Users

Scrambling Code • • • • •

Known as Pseudo Noise Code (PN) 512 Primary Scrambling Codes DL Several million codes UL PN code 1 PN code 1 PN code 4 Differentiate RBS in DL PN code 3 Differentiate user in UL BS 1 transmits on PN code 1 PN code 2 PN code 5

PN code 2 PN code 6

BS 2 transmits on PN code 2

Ericsson WCDMA RAN Functionality

Network Architecture

Ericsson P4 RAN Feature • • • •

Handover Power Control Channel Switching Capacity Management

Handover Capability • Allow UE to have mobility in the connected mode with maintained quality and minimum resource utilization Type of Handover • Soft/Softer Handover • IFHO • IRAT

Handover Flow RNC

UE MEASUREMENT CONTROL

Perform Measurements UE evaluation MEASUREMENT REPORT

Evalutation

Radio Link Add/Remove/Replace?

Execution

Radio Link Allocation/deallocation

ACTIVE SET UPDATE

Radio Link Add/Remove/Replace ACTIVE SET UPDATE COMPLETE

Monitored set calculation

MEASUREMENT CONTROL

Perform Measurements UE evaluation MEASUREMENT REPORT

Power Control Capability • Maintain good quality connection • Minimize UL and DL power utilization

Power Control “basic types” Power control on COMMON CHANNELS ensures there is sufficient coverage to establish connections and transfer date on common transport channels

Power control on DEDICATED CHANNELS (DCH) ensures sufficient connection quality while minimizing impact on other connections.

Cell set-up and cell reconfiguration

Common transport channel setup and reconfiguration

Radio Link Setup

Power Balancing

RAB Establishment Soft Handover (SOHO)

Compressed Mode Inter-Frequency Handover

Power Control on DCH - Overview The RBS and UE uses Inner Loop to send UL and DL TPC’s (transmit power commands). The TPC’s are determined by the outer loop power control.

The RNC and UE uses Outer Loop power control to calculate UL and DL quality targets to which the UE and RNC shall adjust its transmitted power.

P(SIR-Target,UL)

Inner loop DL-TPC

ULTPC

UL-Outer loop

RNC

SIR-Target,UL P(SIR-Target, DL) SIR-Error,UL

DL-Outer loop BLER-Measured,DL

SIR-Target,DL

BLER = Block Error Rate SIR = Signal to Interference Ratio TPC = Transmit Power Control

Open loop P(Startvalue)

Initial Power Setting in UL and DL uses Open Loop. It ensures reliable connection setup, minimal impact on existing connections (UL) and avoids excessive power (DL).

Common Channel Setting Common Channel Powers Power PCPICH: ‘primaryCpichPower’: default = 270(27 dBm) Broadcast Channel: ‘bchPower’: default = -31 (-3.1 dB) AICH: ‘aichPower’: default = -6 (-6 dB) FACH (control): ‘maxFach1Power’: default =18 (1.8 dB) FACH (traffic): ‘maxFach2Power’: default =15 (1.5 dB) RBS

Paging channel: ‘pchPower’:default =-4 (-0.4 dB) Paging indication ch: ‘pichPower’: default =-7 (-7 dB) Primary SCH: ‘schPower1’: default =-18 (-1.8 dB) Secondary SCH: ‘schPower2’: default =-35 (-3.5 dB) 5/ 038 13 - EN/LZU 108 5686 PA15

11

WCDMA Radio Network Functionalit y

Channel Switching Capability • Optimize the utilization of the radio resources by switching the UE to the most suitable transport channel based on the traffic volume, radio resource availability, radio condition, and mobility • Only apply to I/B Packet Services

Channel Switching Types Connected Mode 1. Common to Dedicated

Dedicated Channel (Cell_DCH) Cell_DCH 64/384 kbps UL/DL 2

2 2. Dedicated to dedicated

Cell_DCH 64/128 kbps UL/DL 2

2

3

Cell_DCH 64/64 kbps UL/DL 3. Dedicated to common

1

Common Channel (Cell_FACH) RACH/FACH (max. 32 kbps) 4 Idle Mode

4. Common to Idle Mode

Common to Dedicated Evaluation Monitors if the UE shall be switched from a common to a dedicated transport channel due to large amount of user data buffered in the RNC or the UE. Connected Mode

UL RLC buffer load

Dedicated Channel (Cell_DCH)

Up-switch

Cell_DCH 64/384 kbps UL/DL

X ulRlcBufUpswitch [256 bytes]

Cell_DCH 64/128 kbps UL/DL

and/or Cell_DCH 64/64 kbps UL/DL Common Channel (Cell_FACH) RACH/FACH

Idle Mode

DL RLC buffer load Up-switch

A request is sent to Admission Control to perform an up-switch from Cell_FACH to Cell_DCH 64/64 kbps

X dlRlcBufUpswitch [500 bytes]

Dedicated to Dedicated Coverage triggered Down-Switch Evaluation Monitors if a switch to a lower rate radio bearer is required due to coverage. DL TX code power > [Power Alarm Threshold], defined as Max Code Power – downswitchPwrMargin. A down-switch to Cell_DCH with lower bitrate is requested. Timer coverageTimer starts. Connected Mode

Pcode

Dedicated Channel (Cell_DCH) Cell_DCH 64/384 kbps UL/DL

Cell_DCH 64/128 kbps UL/DL

Cell_DCH 64/64 kbps UL/DL

Common Channel (Cell_FACH) RACH/FACH

Idle Mode

DL TX code power < [Power Alarm Threshold] – reportHysteresis while the timer is running, the down-switch request is cancelled. DL TX code power > [Power Alarm Threshold] – reportHysteresis and timer coverageTimer expires. The downswitch is executed.

Dedicated to Dedicated Up-Switch Evaluation

DL throughput is > 90 % of max. possible bitrate on current radio bearer AND the DL code power is < [Power up-switch threshold] – reportHysteresis, where the [Power up-switch threshold] is defined as Max Code Power – downswitchPwrMargin – Estimated Power Increase – upswitchPwrMargin. Timer upswitchTimer starts.

Monitors if the throughput becomes close to the max user bandwidth and switch to the next higher bitrate radio bearer is required. Connected Mode Dedicated Channel (Cell_DCH) Cell_DCH 64/384 kbps UL/DL

Cell_DCH 64/128 kbps UL/DL

Pcode DL throughput is < 90 % of max. possible bitrate on current radio bearer OR the DL code power becomes >= [Power up-switch threshold] while the upswitchTimer is still running. The timer stops and no up-switch is executed.

[2.9 dB for up-switch from 64-to-128 kbps] [4.7 dB for up-switch from 128-to-384 kbps]

Cell_DCH 64/64 kbps UL/DL

Common Channel (Cell_FACH) RACH/FACH

Idle Mode

DL throughput is > 90 % of max. possible bitrate of current RB AND the DL code power is < [Power up-switch threshold] when timer upswitchTimer expires. The up-switch request is sent Admission Control.

Dedicated to Common Evaluation Monitors if a switch from a Cell_DCH to Cell_FACH is required due to a decrease in transmitted user data. UL and DL throughput increases above threshold downswitchTimerThreshold before the timer expires. The timer stops and no down-switch occurs. Connected Mode Dedicated Channel (Cell_DCH) Cell_DCH 64/384 kbps UL/DL

Cell_DCH 64/128 kbps UL/DL

DownswitchTimer

DownswitchTimer

Cell_DCH 64/64 kbps UL/DL

Common Channel (Cell_FACH) RACH/FACH

Idle Mode

UL and DL throughput falls below threshold defined by parameter downswitchThreshold and timer downswitchTimer starts.

The timer expires and a request is issued to down-switch from common to dedicated channel.

Common to Idle Evaluation Monitors if a switch from Cell_FACH to Idle mode is required due to a complete lack of user data transmission.

Connected Mode Dedicated Channel (Cell_DCH) Cell_DCH 64/384 kbps UL/DL

Cell_DCH 64/128 kbps UL/DL

Cell_DCH 64/64 kbps UL/DL Common Channel (Cell_FACH) RACH/FACH

Idle Mode

If both the UL and DL throughput is zero for a duration specified by parameter inactivityTimer, a request is sent to the Connection Handling function and further to Core via Iu, to release the connection.

Capacity Management Capability • Control the load in the cells and enable the system to provide requested QoS and coverage for the UE Associated features • Admission Control • Congestion Control • Dedicated Monitored Resource Handling

Overview of Capacity Management Channel Switching

Admission Control Admission

Congestion Control

policies

“Resolves”

Admission request

“Prevents”

Dedicated Monitored Resource Handling

Parameters

Monitored resources Compressed Mode & DL spreading

DL code utilization

Air interface Speech Equivalent (ASE)

DL transmitted power

UL received total wideband power (RTWP)

Periodic and event Measurements

RBS HW utilization

DL code Channelization Codes monitor Histogram monitor

DL transmitted carrier power monitor ASE monitor

RTWP monitor RBS HW utilization

Monitors DL code utilization

Compressed Mode & DL spreading

DL transmitted power

Air interface Speech Equivalent (ASE) UL received total wideband power (RTWP) RBS HW utilization

DL code tree utilization (SF for users and CCH’s)

Provides info about # of connections with a certain SF. This adds information about DL channelization usage. Also measure # of connections in compressed mode. Downlink transmitted power, which is affected by # of users, the type of connections and radio conditions in the cell

Estimates UL and DL air-interface usage per radio link.

Total received UL power, i.e. information about UL interference.

Monitors the available HW resources (channel elements) in the RBS)

Admission Request Admission Control

Admission Request Non-guaranteed, non-HO Non-Guaranteed, HO Guaranteed, non-HO Guaranteed, HO

Resource Utilization information Dedicated Monitored Resource Handling

Guaranteed service class • SRB • AMR 12.2 • CS 57.7 • CS 64 • PS streaming 16/64

Admission Request Attributes Setup type (HO or not) Service class (guaranteed or not) Add’l Compressed mode resources (if any) Add’l DL TX power (if any) Add’l DL channelization code resources (if any) Additional ASE’s needed in UL or UL (if any)

Non-guaranteed service class • PS 64/64 • PS 64/128 • PS 64/384 • Multi-RAB (speech+PS 64/64)

DL Channelization Code Admission Policy Reserves HO code capacity, by blocking guaranteed & non-guaranteed non-HO requests if too high DL code tree usage Traffic class / Setup type

• Non-guaranteed / non-HO requests blocked when current DL code resource usage exceeds dlCodeAdm - beMarginDlCode

• Guaranteed / non-HO requests blocked when current DL code resource usage exceeds dlCodeAdm

• Soft congestion is triggered

ng non-HO requests g non-HO requests

Block & soft congestion Block & soft congestion beMarginDlCode

dlCodeAdm

% of DL code tree used

Soft Congestion Soft Congestion implies down-switching an existing non-guaranteed service to a lower DL bitrate due to blocking of a non-guaranteed HO or non-HO request for lower rate or guaranteed HO or non-HO request.

Down-switch of non-guaranteed service Service class of blocked HO or non-HO admission request Non-guaranteed 384 kbps

From

To No down-switch

Order of sequence N/A

Non-guaranteed 128 kbps

384 kbps

128 kbps

N/A

Non-guaranteed 64 kbps

384 kbps

128 kbps

1

128 kbps

64 kbps

2

384 kbps

128 kbps

1

128 kbps

64 kbps

2

Guaranteed

Histogram Admission Policy Controls the SF usage, by blocking non-guaranteed HO and non-HO requests if the DL SF usage and/or compressed mode usage is too high (a way of ensuring distribution of code tree utilization between services)

• Blocks an admission that requests a radio link in compressed mode, when the current number of radio links in compressed mode exceeds parameter compModeAdm.

Blocked

• Non-guaranteed HO / non-HO requests demanding SF32 blocked if the usage of this SF exceeds sf32Adm.

Blocked

• Non-guaranteed HO / non-HO requests demanding SF16 blocked if the usage of this SF exceeds sf16Adm.

Traffic class / Setup type

Blocked

• Non-guaranteed HO / non-HO requests demanding SF8 blocked if the usage of this SF exceeds sf8Adm.

sf16Adm

sf32Adm

sf8Adm Spreading Factor (SF) SF 8 384 Kbps

SF 16 128 Kbps

SF 32 64 kbps

DL Transmitted Carrier Power Admission Policy Blocks guaranteed and nonguaranteed HO and non-HO requests if the DL power utilization is too high

Traffic class / Setup type ng non-HO requests ng HO requests g non-HO requests g HO requests

•

Non-guaranteed / non-HO requests blocked when current DL power utilization exceeds pwrAdm – beMarginDlPwr

•

Guaranteed and non-guaranteed HO and non-HO requests blocked when current DL power utilization exceeds pwrAdm

•

Guaranteed HO requests blocked when current DL power utilization exceeds pwrAdm + pwrAdmOffset

•

Soft congestion is triggered

Block & soft congestion Block & soft congestion Block & soft congestion Block & soft congestion beMarginDlPwr pwrAdmOffset pwrAdm

DL Power usage

Set in relation to parameter maximumTransmissionPower , which is the configured maximum power for all DL channels added together, to be used simultaneously in a cell. The current default setting assumes a max. feeder loss of 6 dB.

ASE Admission Policy Blocks guaranteed and non-guaranteed HO and non-HO requests if the airinterface utilization in the UL and/or DL is too high Traffic class / Setup type

Traffic class / Setup type

ng non-HO requests ng HO requests g non-HO requests g HO requests

ng non-HO requests ng HO requests g non-HO requests g HO requests

Block Block

Block Block

beMarginAseUl aseUlAdmOffset aseUlAdm

UL ASE usage

Block Block

Block Block beMarginAseDl aseDlAdm

DL ASE usage

•

Non-guaranteed / non-HO requests blocked when UL ASE usage exceeds aseUlAdm – beMarginAseUl

•

Non-guaranteed / non-HO requests blocked when UL ASE usage exceeds aseDlAdm – beMarginAseDl

•

Non-guaranteed HO requests and guaranteed non-HO requests blocked when UL ASE usage exceeds aseUlAdm

•

Non-guaranteed HO, guaranteed non-HO and guaranteed HO requests blocked when UL ASE usage exceeds aseDlAdm

•

Guaranteed HO requests blocked when UL ASE usage exceeds aseUlAdm + aseUlAdmOffset

Congestion Control “Congestion”

2

3

Congestion Control

Admission Control 5

1

4

1

Dedicated Monitored Resource Handling DL transmitted power

UL received total wideband power (RTWP)

Cell(s) 1.

Event based measurements

2.

Congestion detected

3.

Order Admission Control to block new connection requests Send periodic measurements (1/s) until congestion resolved Initiate congestion resolve actions.

4.

1 1 Event based Measurements

4 Periodic Measurements

5.

Congestion detection DL congestion detection DL TX carrier power

UL congestion detection UL Received Total Wideband Power

DL congestion detected

pwrAdm+ pwrAdmOffset + pwrOffset

UL congestion detected

U congestion resolved

iFCong + iFOffset

DL cong. resolved

pwrAdm+ pwrAdmOffset

pwrHyst

pwrHyst

iFCong

Time

•

DL cell congestion occurs when the DL carrier power exceeds the configurable threshold pwrAdm + pwrAdmOffset + pwrOffset for a duration longer than pwrHyst.

•

DL cell congestion is considered resolved when the DL carrier power is below the configurable threshold pwrAdm + pwrAdmOffset for a duration longer than pwrHyst.

iFHyst

iFHyst

Time

•

UL cell congestion occurs when the UL RTWP exceeds the configurable threshold iFCong + iFOffset for a duration longer than iFHyst.

•

UL cell congestion is considered resolved when the UL RTWP is below the configurable threshold iFCong for a duration longer than iFHyst.

Congestion resolve handling “UL Congestion”

Congestion Control

Block new guaranteed non–HO and new non-guaranteed non-HO requests

Admission Control

“DL Congestion”

Congestion Control

Block ALL new requests

Start congestion resolve actions in the cell

Admission Control

Cell(s)

Downlink congestion resolve handling Mix of non-guaranteed and guaranteed connections in congested cell tmCongAction tmCongActionNg DL TX carrier power DL congestion detected pwrAdm+ pwrAdmOffset + pwrOffset

tmCongAction

DL cong. resolved

pwrAdm+ pwrAdmOffset releaseAseDlNg

releaseAseDl releaseAseDlNg

releaseAseDl

1. An amount of ASE resources equal to releaseAseDlNg that are associated with non-guaranteed services are released immediately when congestion is detected. If there are still non-guaranteed services in the cell, timer tmCongActionNg starts. 2. If congestion prevails, releaseAseDlNg amount of ASE resources associated with non-guaranteed services are released periodically every time tmCongActionNg has Time started and expires (until the congestion is resolved).

Release order of non-guaranteed services (from highest to lowest ASE in each group) 1.

Non-guaranteed where radio link originated over Iu (to common)

2.

Non-guaranteed where radio link originated over Iur(terminated radio link)

3.

When no non-guaranteed services are left and congestion prevails, the congestion resolve action continues as per slide 30 (only guaranteed services).

3. If congestion still prevails and there are only guaranteed services in the cell, tmCongAction starts. When it expires, releaseAseDl amount of ASE resources associated with guaranteed services are released (periodically every time tmCongAction has started and expires, until the congestion is resolved).

RF Initial Tuning Overview  Workflow  Tool

Overall Process

Tuning Team

Data Preparation

Work Flow KPI & Plots

Data Collection

TEMS Log files

Change Request

Analysis

Need Detailed Analysis Post Processing

Change Request

O&M Team

Support Team

UETR & Trace Setup

UETR Log files

Detailed Analysis

Site Availability Check

Alarm Check & Site Healthy Check

RNC Trace files

Alarm Lists

TR & CSR

Problem Category

Initial Tuning Basic Concept • Optimise tilts – Reduce Pilot Pollution – Reduce Active Set Size – Maximise EcIo and RSCP

• Optimise Neighbour lists – Maximise mobility – Decrease HO Failures

• Identify Network Faults – HW installation errors – UTRAN problems

Tools • TEMS Investigation – Scanner – UEs

• • • • •

NeXplorer MCOM3g UETR Explorer Post Processing Tool (KPI Calculation) RF Problem Sheet

Case Study

Case Study RF Issue • Pilot Pollution • Low Coverage, Quality • Missing Neighbor • Uplink Coverage Problem • Uplink Interference Network Issue • Swapped Feeder • Neighbor Definition (Site Down) • Co SC Issue • AAL2 Failure

UE Issue • UE Frozen • No acknowledge at Preamble

RF Issue

Pilot Pollution Pilot Pollution is defined to be the degradation in Ec/No of the best serving pilot owing to the presence of the other pilot signals received at a similarly high level, but which do not contribute constructively to the received signal.

While • Threshold_PilotPollution = ReportingRange1b (5dB)

Pilot Pollution (2)

Low Coverage, Quality

Low Coverage & Quality

Missing Neighbor • Required Neighbor Relation is not defined • The Cell becomes interferer • Call drop when the delta of the RF measurement between the cell and the best cell is greater than releaseConOffset

Missing Neighbor (2)

Uplink Coverage Problem

Uplink Interference

Network Issue

Swapped Feeder

Neighbor Definition (Site Down)

Co Scrambling Code Issue

Co Scrambling Code Issue (2)

Neighbour list & combination Active set

Neigbour list is defined every cell individually but must be combined in a unique list when handovering

Monitored set – the union of neighbours from all cells in the active set

Duplicate cells are removed

Neighbour list & combination •

• •

•

Neighbour combination accordes to NB combination algorithm. Shared NB cells only could be added once a time. The maximum cells of monitor set is restricted by C_MaxSohoListSubset (=32) Redundant cells exceeding C_MaxSohoListSubset in the monitored set should be removed.

max 32 cells cell A31

Truncated cells- ”unmonitored set”

cell B31 cell C31

cellx Undefined neighbors

celly

NB Combination Algorithm NB combination algorithm ran at RNC side

Sample: e1a no DRNC

1. Setup a call: intially UE use the NB list contained in SIB 11. 2. Then RRC connection completed, first measurement control will be sent down to UE to tell what NB list should be used.

1.Setup a call 2.Measurement control Moved to a new cell

Continually listen the system information on BCH- SIB 11 gives the neigbour information

3.Active set update 4.measurement control

3. With moving to new cell, active set update would occur, then RNC combines two neigbour sets into one unique monitored set list. 4. New measurement control will be sent after active set updated. Contains the new monitored set information for UE.

NB Combination Algorithm A B C A1 B1 C1 A2 B2 C2 A3 B3 C3 A4 B4 C4 A5 B5 C5

A B A1 B1 e1b cell C dropped

A2 B2 A3 B3 A4 B4 A5 B5

e1a, new cell D added,it has 32 NBs in its neigbourlis t

A B D A1 B1 D1 A2 B2 D2 A3 B3 D3 A4 B4 D4 A5 B5 D5

e1c, new cell E replace cell B ,it has 32 NBs in its neigbour list

Truncated cell below this line could not be added into active set, even those NBs are defined in the RNC

A E D A1 E1 D1 A2 E2 D2 A3 E3 D3 A4 E4 D4 A5 E5 D5 D6

…

…

D18

D18

Scenario: •Intra-frequency •No shared NB cell exsiting

Only 5 NBs with top priority in the defined NB list of cell D can be added into new monitored list, big problem!!!

AAL2 Failure

UE Issue

UE Frozen

No Acknowledge at Access Preamble