Successfully Deploying a 3G/UMTS Network — Some keytechniques for launching a 3G network on time withoptimal performance

By deploying the latest 3G/Universal Mobile Telephone System (UMTS) networks, service

providers can take advantage of the growing demand for new, converged mobile voice,

video and data applications and services.

This white paper:

• Discusses the drivers that are creating a market for new mobile, UMTS-based services; and

• Describes some of the key considerations when deploying a 3G/UMTS network, and

techniques used to achieve high levels of optimization

T E C H N O L O G Y W H I T E P A P E R

Table of Contents

1 Introduction

2 Planning and Deploying the 3G/UMTS Network

2 RF Design

2 RNC Planning and Configuration

3 Initial Neighbor List – UMTS

4 Initial Neighbor List – IRAT

4 Drive Routes and Cluster Definition

4 Database and Antenna Concerns

4 Making It All Work

5 About the Author

1Alcatel-Lucent | Successfully Deploying a 3G/UMTS Network

Executive SummaryTo take advantage of growing consumer and business demand for mobile converged services,including voice, video, and data applications, service providers need to deploy 3G networksand make sure they are fully integrated with their existing 2G networks.

This white paper presents an overview of some of the more important techniques and consid -erations that a UMTS deployment team should take into account during the design, optimizationand deployment phases of a 3G upgrade. These techniques have helped implementation teamsachieve high levels of success from the initial optimization drive to the end stage when 100 per -cent of the clusters have been accepted with acceptable performance.

IntroductionThe telecommunications marketplace is changing rapidly, placing increasing emphasis on pro -viding consumers with personalized lifestyle services and mobility. There has been an explosionin the availability of sophisticated user devices that support integrated voice, data, and videoapplications. According to a UMTS Forum white paper, at the end of 2006 consumers had achoice of more than 400 WCDMA terminal designs worldwide representing handsets optimizedfor voice, video, and other multimedia services.1 UMTS also estimates that worldwide 3Gsubscribers will exceed 275 million by the end of 2007. By the end of the decade, the total of global 3G WCDMA subscribers should approach 800 million.

Driving consumer acceptance and increased demand are new features such as high resolutionsscreens, multi-megapixel cameras with quality optics, fast USB and WiFI connectivity, andlarge amounts of removable storage capacity such as compact flash, memory sticks, and otherformats that can store gigabytes of music, pictures, and videos. The business market is equallyactive with handsets equipped with business-oriented operating systems, keyboards for textentry, and PDA handhelds that are moving into the territory that was once exclusively heldby notebook PCs. 3G/UMTS will make possible a whole new range of mobile data applicationssuch as telemedicine, electronic banking, and location-based services.

Mobile TV, video, and music are three hot new services. Better phones with high resolutionscreens featuring large color palettes, combined with improved power management, are helpingdrive the demand for mobile TV, a premiere applications based on 3G/UMTS-based services.Mobile video is another killer application — witness the number of video clips created on mobiledevices that are posted daily to YouTube. And mobile music — downloading songs to your mobiledevice — although currently accounting for only a small percentage of service provider ARPU,is growing rapidly.

All of this activity presents service providers with great opportunities — and some formidablechallenges as well.

Alcatel-Lucent studies indicate that customers are increasingly looking to bundle their variouscommunications services and have no qualms about switching if their provider is unable to offera whole range of new 3G services backed up by high levels of quality of service (QoS). Thismeans service providers have to present their subscribers with a top notch service experienceand QoS for content-based services, while, at the same time, re-engineering their operations tosignificantly increase service velocity. To achieve this goal they must be able to cost-effectivelymanage the migration to 3G/UMTS.

1 “3G/UMTS Evolution: Towards a New Generation of Broadband Mobile Services,” UMTS Forum white paper, December 2006, p. 2.

2 Alcatel-Lucent | Successfully Deploying a 3G/UMTS Network

Planning and Deploying the 3G/UMTS NetworkIn order to take advantage of the rapidly growing market for new converged mobile services,operators need to not only deploy UMTS, but to make sure that the 3G service is integratedwith its existing 2G GSM network. In working with its service provider customers, Alcatel-Lucent has employed a variety of techniques to bring their UMTS clusters (a group of 20~25contiguous NodeBs) to acceptable performance status within a significantly compressed time -line. Key areas addressed by the deployment teams include:• RF Design;• RNC planning and configuration;• Initial neighbor list – UMTS;• Initial neighbor list – IRAT; and• Drive route and cluster definition and 3rd party audit of antenna installation

RF DesignFundamental to a successful UMTS deployment is an excellent design that has as its foundationhigh quality geographic data and accurate signal propagation models. Developing the rightpropagation models is essential — failure to do so can compromise the entire deployment. 3G networks demand rigorous precision;

A hefty percentage of the initial design time — in some cases, a month or longer — can beexpended in identifying the right sites in the target market area. This essential preliminarywork includes gathering, sorting, and tuning data in order to simulate actual market conditionsin the target area and develop accurate propagation models assigned to the appropriate cellsor sectors in both the 3G and 2G spectrums. Continuous wave (CW) tests performed overboth spectrums (for example, at 1900 and 850 MHz) ensure the validity of the UMTS andGSM propagation models.

RNC Planning and ConfigurationR N C P L A N N I N GWithin the market area being upgraded to a 3G network, one or more Radio Network Controllers(RNCs) are used to control the base transceiver station (BTS) — referred to as Node-B in UMTSterminology. Node-B uses WCDMA as its air transport technology.

One of the primary goals in developing the 3G network is to limit the number of RNC rehomes.Rehoming can be expensive: making changes can result in service outages and tying up resourcesthat can be used to greater advantage elsewhere. These problems can either be avoided or mini -mized through careful RNC planning up front.

In order to reduce interruptions in the deployment of the wireless network and improve per -formance, there are three main factors to be considered — capacity, geography, and last, butnot least, the number of handoff counts in the underlying GSM system.

Configuring the RNCs should take into account the voice erlangs performance counts in theexisting GSM systems, the data throughput, and, as stated above, the handoff counts. Armedwith this information, the development team can then calculate the predicted UMTS capac -ity carried by each RNC. These calculations allow the network designers to limit the numberof Node-Bs in the UMTS system.

3Alcatel-Lucent | Successfully Deploying a 3G/UMTS Network

R N C C O N F I G U R A T I O NThe next step is to identify the geographic borders of the RNCs and the RNC handoff countswithin each Node-B. Where the handoff counts are high, the handoffs can be kept within asingle RNC. This increases the capacity of the RNC and cuts down on the number of inter-RNC handoff that would ordinarily be made by subscribers as they move between RNCs. Thisstrategy also results in a fewer number of IuR (Inter RNC interface Links) trunks, as well asincreased network performance.

Figures 1 and 2 show the before and after stages of a redesign of a RNC configuration in atypical metro market area.

Initial Neighbor List – UMTSAnother major boost to optimizing the network and saving deployment and implementationtime can be realized by constructing a comprehensive neighbor list. There are three stepsinvolved in creating this list:• MSC dump – First the GSM handoff counters from the MSC (mobile switching center)

dump are obtained. In most situations this dump will have both 850 MHz and 1900 MHzhandoff counts. Because the UMTS system operates at 1900 MHz, the 850 MHz GMScounts can be ignored at this point.

• GSM handoffs – Next the number of GSM handoff attempts between the cells (sectors) is calculated and used to prioritize each UMTS neighbor relation.

• Verification – Finally the design team needs to verify that the neighbors are valid using apropagation tool such as Asset 3G.

These steps allow the team to quickly identify and add missed neighbors in the initial drives,allowing the team to move on to the next, more complex phases of the network design.

Figure 2. Final RNC configuration after taking capacity and otherfactors into consideration*

*Notice that the size of the middle RNC has been substantially reduced.

Figure 1. Initial RNC configuration based on geography and cell count

4 Alcatel-Lucent | Successfully Deploying a 3G/UMTS Network

Initial Neighbor List – IRATOne of the hallmarks of good wireless network design is the integrity of the handoffs betweenthe 2G and 3G networks. The same techniques used to define the UMTS neighbors can alsobe used to create the initial IRAT (Inter Radio Access Technology) neighbors. However, inthis case, to enable a smooth handoff both the cellular 850 MHz and PCS 1900 MHz GSMneighbors are used to define the UMTS IRAT neighbors. Processes that ensure integrity betweenthe 2G and 3G systems should be in place prior to the creation of the initial Inter Radio AccessTechnology (IRAT) neighbor lists. These processes need to be communicated to all membersof the team. By taking these steps, you can effectively reduce unwanted drops and minimizeperformance issues across the UMTS border.

Drive Routes and Cluster DefinitionNormal procedures are used to define the drive routes and cluster definitions. These routes andcluster definition will be used for performance testing. However, it is important to ensure thatdrive routes are well within the coverage criteria and that the cluster definition is confined tothe same RNC.

Database and Antenna ConcernsA well constructed, well scrubbed database is essential for successful network design and oper -ation. The database, which houses the geographic information, should be scrubbed frequentlyto make sure that all UMTS translations and UMTS and IRAT neighbors are up-to-date. Thisincludes coordinating GSM rehomes and retunes from the inception of the project — thisallows the UMTS team to apply changes to the GSM Location Area Code (LAC) and theBroadcast Control Channel (BCCH).

Prior to optimization it is also a good idea to conduct a 3rd party audit of the construction andinstallation work done by the vendor responsible for antenna installation. Often this auditcan uncover problems that negatively impact the network — for example, inconsistencies in setting up antenna azimuth and tilt during installation which can reduce overall networkperformance. Identifying these problems early in the project can substantially reduce thenumber of optimization drives.

Making It All WorkThe techniques described above are just a few of the more important considerations that aUMTS team needs to take into account when implementing a 3G/UMTS network in con -junction with an existing 2G deployment.

However, there is one other matter we did not discuss. Quite often there are a number of teamsand individuals representing different organizations – i.e., the customer, service provider, vendors,and consulting firms. Effective communications between these entities can facilitate daily fine-tuning of the strategic plan. This can go a long way toward meeting objectives and milestonesall the way from the beginning of the design phase to optimization and launch.

About the AuthorMallik VagvalaSWAT Team Lead – UMTSAlcatel-Lucent

Mallik Vagvala is currently based in Whippany, New Jersey with the Alcatel-Lucent ServicesGlobal Engineering Team. In his current role as SWAT Team Lead — UMTS, he is responsiblefor End to End UMTS Network Performance. Mallik also played a RF PM / Market Lead –RF role. In this role he was responsible for the Design and Optimization of UMTS markets inPhiladelphia, Trenton, Wilmington, Harrisburg, Allentown, Wilkes-Barre and Atlantic City.Prior to that Mallik played a major role as Regional RF Lead — EVDO for Verizon Wireless.For the last seven years in Alcatel-Lucent Mallik worked in the areas of RF design, optimi -zation, performance, and planning for mobile networks in CDMA2000 1-X / EVDO etc…Prior to joining Alcatel-Lucent he worked for various companies for 10 years on Network per -formance in GSM /CDMA / Wireless Local Loop technologies. He holds a First Class withDistinction degree in Electronics and Communication Engineering from Andhra University,Visakhapatnam, IN.

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