Nemo Drive Test on 2G/3G

Networks

Toha Ardi Nugraha Trainer at Expert Coaching Clinic

Network Optimization Process

Reason of Drive Test?

1. Network Performance Monitoring

2. Maintenance

3. Benchmarking

4. Customer Complains

Module 1 : Overview 3G System (1 hour)

Module 2 : Drive Test Concept (1,5 hour)

Module 3 : Drive Test on Field (2,5 hour)

Module 4 : Reporting (2 hour)

Module 5 : Analysis (2 hour)

OVERVIEW 3G SYSTEM

Module 1

Data Transmission

GSM & UMTS Evolution

3G/UMTS Architectures (Migration)

Specification of GSM

Frequency band :

Uplink 890 915 Mhz

Downlink 935 960 Mhz

Duplex spacing : 45 Mhz

Carrier spacing : 200 khz

Modulation : GMSK

Access method : FDMA / TDMA

GSM network Architecture (contd)

3 Subsystem in GSM network

- BSS (Base Station Subsystem)

- NSS (Network and Switching Subsystem)

- OSS/OMC (Operating and Support system or

Operating and Maintenance Centre)

GSM network Architecture (contd)

BSS (Base Station SubSystem)

BTS (Base Transceiver Station)

- Radio equipment

- To transmit and Receive signal to MS

- Defined a Cell coverage

depend on the power transmit

BSC (Base Station Controller)

- RRM for several BTS

- Handover management

TRAU

- Rate adaption

GSM network Architecture (contd)

NSS (Network and Switching Sub System)

MSC (Mobile Switching Centre)

HLR (Home Location Register)

VLR (Visitor Location Register)

AuC (Authentication Center)

GSM network Architecture (contd)

Operation and Support System

Control and Monitor the Network

- NMC (Network Management Centre)

- Some OMC are controlled by NMC

- OMC (Operation and Maintenance Centre)

GSM Frequency Bands

GSM type Frequency Band

Uplink (UL) Downlink (DL)

GSM 900 890-915 Mhz 935-960 Mhz

GSM 1800 (DCS 1800) 1710-1785 Mhz 1805-1880 Mhz

GSM 1900 (PCS 1900) 1850-1910 Mhz 1930-1990 Mhz

GSM Channelization

Physical Channel

200 Khz (Frequency Carrier) consist of 8 TS

Logical Channel

Control Channel

Traffic Channel

Control Channel

Traffic Channel

GSM channelization (Contd)

Logical channel

Chontrol Channel

Broadcast channel

Common Control Channel

Dedicated Control Channel

Traffic Channel

Full Rate Half rate

3G/UMTS Concept

WCDMA Concept

UMTS Architecture

Channelization

Handover

WCDMA - Wideband CDMA

Radio access technology for one of the UMTS access modes (UTRA FDD) using 5 MHz duplex channels.

Frame length is of 10 msec, Chip rate is 3.84 Mcps

All users share the same frequency and time domain

Users separated by the codes

UMTS Radio Frequency Ranges

FDD (Frequency Division Duplex)

TDD (Time Division Duplex)

Channelization in UMTS

Logical Channel between RLC and MAC

Specific for information types

What type of data to be transferred

Transport channel between MAC and PHY

Specific for how to transfer information? (quality guarantee)

How and with which type of characteristic the data is

transferred by the Physical

Layer

Physical Channel Exact Physical characteristics of the

radio channel

WCDMA Channel (Cont.'s)

Spreading means increasing the signal bandwidth

Spreading includes two operations Channelization (increases signal bandwidth)

Orthogonal Spreading

Scrambling

(does not affect the signal bandwidth) Use pseudo-noise codes

Handover Concept

Site B Site A

BSC

Posisi 1

Posisi 2

Posisi 3

Handover

Request

Handover

Request

Handover Req

Acknowledge

Handover Req

Acknowledge

Handover Req

Acknowledge

Handover

command Handover

Complete

Handover: Types (2G)

Intracell handover MS moves from one sector to another sector within

same cell

IntraBSC handover MS moves from cell to another cell within same BSC

IntraMSC handover MS moves from cell to another cell from different BSC

within same MSC

InterMSC handover MS moves from cell to another cell from different BSC

and different MSC

Handover: Types (3G)

Intra-System handovers

Intra-frequency handovers

Soft, Softer

Inter-frequency handovers

Hard

Inter-System handovers

Handover between WCDMA GSM (Hard)

Handover between WCDMA/FDD TDD

(Hard)

Pilots Set

The handset considers pilots in sets

Active : pilot of sector actually in use

Candidate : pilots mobile requested, but not yet set up & transmitting by

system

Neighbors: pilots told t mobile by system, as nearby sectors to check

Remaining: any pilots used by system but not already in the other sets

Soft Handover Algorithm

AS_Th AS_Th_HystAs_Rep_Hyst

As_Th + As_Th_Hyst

Cell 1 Connected

Event 1A

Add Cell 2Event 1C

Replace Cell 1 with Cell 3

Event 1B Remove Cell 3

CPICH 1

CPICH 2

CPICH 3

Time

Measurement

Quantity

T T T

DRIVE TEST CONCEPT

Module 2

Network Environment

UMTS Drive Test is testing and measuring performance of 3G/UMTS network.

Tools :

1. Software Nemo Outdoor

2. PC laptop

3. GPS

4. Scanner

Reason of Drive Test?

Network Performance Monitoring

Maintenance

Benchmarking

Customer Complains

Continuous Drive Test

Drive Test (outdoor)

GPS

Walk Test (indoor)

Pin point/way point

Analyze Data Collection

Analyze data that was collected before

(from Log files)

To know some problems in current area

Reporting

To Answer Analyze Data Collection (Objective Answer)

Optimization Consideration

Recommendation

Parameters DT GSM

1. Rx Level

2. Rx Qual

3. SQI

4. Cell Id, BSIC

5. TA (Timing Advance)

6. ARFCN, etc

Parameters DT UMTS

UARFCN (UMTS Absolute Radio Frequency Channel Number)

RSCP (Receive Signal Code Power)

RSSI (Receive Signal Strength Indicator)

SC (Scrambling Code)

Ec/No

UE TxPower (dBm)

Throughput

BER, etc

Step 1:

Start >Settings> Control Panel > System

Or My Computer >

Manage > Device Manager

Open Device Manager

Step 2: Choose Hardware Tab in System Properties >

Click Device Manager.

Open Device Manager

Step 3 :

Look port to conect hardware

(Modem)

Scanner/GPS & Check COM

Ports

Connect UE & Check COM Ports

Double click the 3G Modem to check Trace port number > Check

under Modem Tab.

For UE Modem:

In device manager view:

Start Nemo Outdoor 5.07 and Load

Workspace

Make sure the Nemo dongle is connected to the laptop.

Launch Nemo Outdoor 5.07.

Load the desired workspace.

Workspace should contains adequate information for the user to monitor.

Different workspace should be created for different setup configuration.

Nemo workspace are stored proper folder for easy access, eg.

C:\Nemo Tools\Nemo Outdoor\Workspaces

Running Program

Start >Program Files > Nemo Tools > Nemo Outdoor 5

Workspace

Details

Device Configuration

Load a measurement

User Interface Nemo Outdoor 5

Worksheet

Device graph

Load Workspace

Step 3: Browse to Nemo Workspace Folder -> Select workspace > Click Open.

Create Workspace

Parameter

Add Devices

Step 1: Go to Measurement workspace > Add New Device.

Step 2: Click the Configuration part

> Trace port and Modem port

Nemo Interface

Map Interface

Open map (.tab)

Nemo logfiles and other files are stored proper folder for easy access, eg.

C:\Nemo Tools\Results (.nmf)

DRIVE TEST ON FIELD (OUTDOOR)

Module 3

REPORTING

Module 4

Map Info

Exporting from Nemo Outdoor

Select Parameters

Reporting KPI with Map Info

Layer Control

Symbol

Create Thematic Map

Define Network Performance

Open Table

Export to Map Info

Select Parameters

Report KPI With Mapinfo

KPI (Key Performance Indicator) : key to detemaint Network performance.

like as , RSCP, Ec/No, etc

Mapinfo is Software for loading and mapping geogharphic analysis

File > open file (chose file extention .tab)

Ex : bandung.tap

Used Layer control

Open Log files

Example file (.tab)

Layer Control

Command:

View

Edit

Create Symbol

Create Thematic Map

Create Thematic Map (Cont.'s)

Create Thematic Map (Cont.'s)

Reporting with Map Info

Open Table

ANALYSIS (TUNING THE NETWORK)

Module 4

UMTS Optimization

3 Mayor Steps in Optimizing Network

UMTS performance indicator

Problem Signature

Tuning network

Specific Neighbor list

Managing excessive soft handoff

3 Mayor Steps in Optimizing Network

RF optimization is the process of measuring,

analyzing, and tuning and existing network to meet network performance criteria

It usually occurs after the network planning is completed

It can be performed frequently to respond:

Changes or growth in the network

Customer complaints such as coverage,

dropped call etc.

The need to improve capacity.

UMTS Performance Indicator

KPI Target :

RSCP (good > -85 dBm)

Ec/No ( > -8 dB)

BER (98%)

Analyze Pilot Pollution Area

Drop Call Rate (DCR)

HSR (Handover Success Rate)

Call Setup Success Rate (CSSR)

Problem Signature

Missing Neighbor or No Neighbors defined for Site. (Database)

Poor Coverage Area.

Pilot Pollution Area

Poor Coverage Area

Test mobile measurements

Antenna configuration check

Verification of RF network design

Propagation model verification

Link budget analysis

Improving coverage

Cell spliting, Sectorisation

Difficult , Expensive

Primarily used for capacity enhancement

Overlaid cell structure

Micro- and picocells

Cellular repeaters

RNC

Node B

Node B

Node B

Node B

Pilot Pollution

Active set UE > 3 and in range 5 dB or approximately 3 dB from the biggest active set.

Reduce system performance,

Antenna Fine Tuning

Horizontal plane

Possible coverage weakness between sector

Interference reduction

Traffic load distribution

Vertical Plane

Interference reduction

Possible coverage weakness in the short to medium distance range

Traffic load distribution

Tuning the Network

Solution (Antenna Adjustments)

Include :

Down tilting

Antenna Height

Azimuth

Type of antenna

Reason of Down tilting:

1 Reduce interference

2 Optimizing cell

Antenna Configuration

General points to check

antenna type, e.g.

omni

directional 60, 90 or 120 degrees

electrical downtilt

antenna azimuth angle (for directional antenna)

coverage targets

antenna tilt angle

electrical + mechanical

diversity & isolation

e.g. space diversity,

polarisation diversity

Type Antenna Down tilt

Mechanical down tilt

Physic, Sectoral

Electrical down tilt

Easy

0 0

Electrical Mechanical

Typical antenna beam pattern

Omni vs. Sectorised

OMNI cells - more difficult to optimize Electrical down tilt possible, however

same for entire cell

Parameters same for entire cell

Directional antenna narrower beam easier to control interference

tilting less efficient with wider beams

Sectorised cell site with different

downtilt angles

Reference

Short Course In Building DCS 1800 Coverage, Mobile Communication Laboratory, 2009

Short Course Drive Test UMTS, Mobile Communication Laboratory, 2008

Short Course Drive Test CDMA 2001x and Optimization, Mobile Communication Laboratory, 2008

Short Course CDMA Drive Test and Optimization, Antenna Laboratory, 2007

Nemo_Outdoor_manual

Thanks