3G INTRODUCTION

3G System

3G Systems are intended to provide a global mobility with wide range of services including telephony, paging, messaging, Internet and broadband data.

Universal Mobile Telecommunication System (UMTS)

UMTS is one of the Third Generation (3G) mobile systems being developed within the ITU's IMT-2000 framework.

UMTS Services

UMTS offers teleservices (like speech or SMS) and bearer services, which provide the capability for information transfer between access points.

UMTS Network ServicesHave different QoS classes for four types of traffic

Conversational class (voice, video telephony, video gaming)

Streaming class (multimedia, video on demand, webcast)

Interactive class (web browsing, network gaming, database access

Background class (email, SMS, downloading)

Bearer services Offered data rate targets are:

144 kbits/s: satellite and rural outdoor 384 kbits/s: urban outdoor 2048 kbits/s and higher data rates:

indoor and low range outdoor 21.4 Mbps and 42.8 Mbps have been

launched in some areas like U.A.E

144 kbits/s and 384 kbits/s are called “R99”. (Release 99)

Higher Data rates are called HSPA (High speed Packet Access)

HSUPA: High speed uplink Packet Access HSDPA: High speed Downlink packet

Access

Frequency Band

Frequency band 2100 MHz Uplink/Downlink Band 5MHz Uplink Frequency band 1920 to 1980

MHz Downlink Frequency band 2110 to 2170

MHz UARFCN is the channel number

UARFCN

The UARFCN (UTRA Absolute Radio Frequency Channel Number) is the channel number representing the full 5 MHz UMTS carrier.

Only 3.84MHz is used for transmission, while the 116 kHz acts as a built-in guard-band to adjacent UARFCN's (580kHz + 3840kHz + 580kHz = 5MHz).

If an operator owns the adjacent frequency bands, it is possible to reduce the size of the UMTS carrier from 5MHz to 4.4 or 4.2 MHZ, but this is not recommended.

CPICH & Scrambling Codes

The Common Pilot Indication Channel (CPICH) is broadcast from every cell

It carries no information and can be thought of as a “beacon "constantly transmitting the Scrambling Code of the cell

It is this “beacon” that is used by the phone for its cell measurements for network acquisition and handover purposes (Ec, Ec/Io)

Every cell contains different Scrambling code Total scrambling codes are 0 to 511 i.e. 512 Codes Wide range of scrambling codes reduces frequency

clashes Golden Rule: If the UE can’t see the CPICH the UE can’t

see the cell.

3G Coverage Measurements

Initial 3G network optimization will be performed purely from CPICH measurements

Three key related measurements for 3G optimization are Ec, Io & Ec/Io.

Ec: The Received Signal Level of a particular CPICH (dBm)

Io: The Total Received Power in dBm (Including Background Noise)

Ec/Io: The CPICH Quality (The ratio of the above two values)

RSCP: Receive Signal Code Power

3G Drive Test

Two MS and one scanner used for 3G Drive Test.

MS1 Idle MS2 Dedicated MS3 Scanner, Scans 2G and 3G data Tems Investigation Data collection is used

for Drive Test.

3G Scanners

Dual band (3G/2G) scanner are used. DTI scanner has added benefit of 2G

scanning. Ideal for 3G-2G neighbor optimization as

well as 2G optimization.

SOAR

Site On Air Acceptance Report Includes SSV and Single site Drive Test SSV: Single Site Verification Test SOAR report is attached for your

reference

Microsoft Office

Word 97 - 2003 Document

SSV Single Site Verification Test SSV test is performed at every cell, SSV Includes Voice calls Video Calls SMS MMS 3G to 2G HO 2G to 3G Cell reselection (As 2G to 3G HO is not allowed in

many networks) R99 DL/UL HSDPA HSUPA If operator has more than one UARFCN than SSV will be

performed at every UARFCN.

IBS Drive Test IBS: Indoor Base station Includes SSV & Walk Test for all sectors Out door to in door HO and Indoor to

Outdoor HO is also required for IBS Tems Mobile Pocket View can also be

used for walk test IBS report is attached for your reference

Microsoft Office Word 97 - 2003 Document

R99 and HSPA Test

R99 is done through MS R99 can be done by HSPA data card. While HSPA test is done by HSPA Data

card as Ms cant deal with high data rates like 21.4 Mbps or greater data rates.

Many of MS cant deal with more than 3.5 Mbps.

Du meter is used for throughputs calculations during Test.

AS, MN and DN

AS: Active Set, Include the cells sharing the radio resources

Maximum 3 cells can be in Active Set state in one time

MN, Monitor Set, Includes neighbor information

DN: Detecting neighbor, includes the information of detecting neighbor. MS receives good RSCP of not added neighbor cells.

Event1A, 1B and 1C

1A: It will Add the monitor(Candidate Set) to Active Sent

1B: It will move the Active Set cell to Monitor Set

1C: Replacement between Active Set cells on the bases of Ec/Io.

These Events are occur in dedicated mode.

If one of these event could not trigger due to any reason, call will be dropped.

Handovers in WCDMA

Various handover types exist in WCDMA

Those between WCDMA sites (intra-system HO)

Those between WCDMA and GSM (inter-system HO)

SHO

Softer handover/Soft Handover During SHO, MS uses the resources of both

cells, source and the target cell at the same time

Softer handover occurs between sectors of the same Site

Soft Handover occurs between the sectors of the same RNC

For both softer and soft it is the Ec/Io levels used to determine whether a cell should be added or removed from the active set

Inter frequency HO

Inter frequency handover occurs between two WCDMA carriers (UARFCN)

Will be used once operator deploys its second carrier, for microcell layer or capacity purposes

Inter system HO

Inter system handover occurs between 3G and 2G sites

As with all handovers, accurate adjacencies will be required 3G & 2G

Pilot Pollution

In scan mode, when 3 or more than 3 pilots are serving at the same place with RSCP better than -100 dBm and Ec/No is better than -15 than there will be pilot pollution.

New Sites: Additional sites may reduce pilot pollution by bringing dominance to an area

Solution: 3G Scanner Survey, Analysis, Downtilts, New Sites

The End