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White Paper

WEBSITE: www.jdsu.com/test

Maximize the Customer Experience with 3GPP Mobile Data ServicesBy: Juergen Voss, Solution Architect and Graham Byars, Product Manager

IntroductionThe rising popularity of smartphones has led to massive growth in the volume and complexity of data traffic carried on wireless networks. This explosive growth is unrelentingand will continue to contribute to customer ARPUonly as long as customers are happy with the quality of their service.

In this volatile environment, sub scribers and operators share a crucial point of potential dissatisfaction: support calls. These are becoming more complex, are taking longer to resolve, and can cost millions in customer care.

A variety of issues can lead to dramatic increases in the number and complexity of support calls:

The mere introduction of data-capable smartphones and the accompanying servicesNetwork element (NE) configuration errors that impact data servicesThe guarantees and expectations that accompany corporate or VIP service agreementsDiminished service quality caused by rogue users consuming massive amounts of bandwidthComplaints from customers who are shocked by unexpected charges for data usage they didnt initiate (e.g.,

automatic software updates by PCs connected via 3G dongle)

The ability to quickly identify the underlying problems and successfully resolve support calls depends on a highly scalable assurance solution that provides full-time monitoring and includes an integrated suite of monitoring and troubleshooting applications. A scalable solution that provides speed, accuracy and insight will put operators on the fast track to improved revenues, happy subscribers and a growing customer base.

Speed: When answers are no more than three clicks away, a prompt, successful resolution is more likelyAccuracy: With accurate, impartial data from the network, operators and their support personnel can be

more confident in their decisions Insight: An end-to-end solution with comprehensive real-time and historical data provides a broader view

for fast, accurate troubleshooting

The remainder of this paper provides a closer look at the issues faced by network operators; describes monitor-ing methods and optimum monitoring points; outlines the key elements of an advanced solution; and presents examples based on the JDSU packet core monitoring solution.

White Paper: Maximize the Customer Experience with 3GPP Mobile Data Services 2

Issues Faced by Network OperatorsOperators with GPRS/UMTS packet data networks face a number of multi dimensional challenges, spanning handset proliferation, radio resources, customer subscriptions, service issues and network issues. A closer look at each of these will highlight the potential sources of problems.

Handset proliferationMarket forces have driven the rate of smartphone introductions to unexpected levels. This proliferation is accompanied by a number of assurance challenges:

Device configuration and authenticationDevice performance in general, and when using specific servicesA massive increase in signaling generated by new smartphones

Radio resources and allocationService is influenced by the radio access network used by the customer. The actual radio resourceGPRS, UMTS, LTEthat is used and allocated has a strong influence on service performance and service activation time.

Customer subscriptionsThe presence of different tariffs and subscription services increases the complexityand difficultyof trou-bleshooting a customer issue:

Which access point name (APN) was used? Which APN is the customer allowed to use?Which service was requested and which radio resource capabilities were allocated?How much latency does the signaling system cause?Are pooling and IP tunneling working properly?

Service issuesUltimately, packet data services can be successful only if the customer can access those services and receive the expected quality of service:

They can easily access websites, email, FTP and WAP servicesDownload and upload performance is good, and the expected amount of data is transmittedNo surprises: Usage credits arent consumed by automatic downloads not initiated by the user

Network issuesAny bottlenecks in a mobile data network will make it difficult to set up and deliver user services:

Overloads in the RNC, SGSN or linkExcessive latency or retransmission in an NE

Operators that meet these challenges can deliver consistent, high-quality service for their customers. The first step is choosing a scalable monitoring solution that is easily integrated into operational processes.


Defining an Effective Tool SetIts true that almost every service issue can be addressed with either readily available free tools or through logs from the network elements. However, these free tools may not be as useful or cost-effective as they may seem.

Historically, troubleshooting has been a niche skill occupied by a handful of highly skilled network experts. As data traffic grows it can become exponentially less efficient and more expensive to use technical experts such as Tier 2 or Tier3 engineers to collect data and resolve issues. The time required to address each problem can add up rather quickly. This is counter to the desire for faster problem resolution and greater customer satisfaction.

To make matters worse, these tools may not scale effectively as data traffic grows at 500 to 1000 percent per year. If data is lost or response times decrease, then problem resolution will take longer and customer satisfaction will be affected.

A scalable and easy-to-use commercial monitoring/troubleshooting solution will have several highly benefi-cial attributes: data management, session analysis and session tracing. A closer look at each of these will provide a clearer picture of their benefits in high-growth situations.

Data management: In a typical day, a normal BSC/RNC/SGSN/GGSN could generate 13 TB of data. A well-designed commercial solution will provide a significant amount of data reduction, perhaps from tens of terabytes down to hundreds of gigabytes; it will also manage data storage. A decentralized solution will provide scalability and rapid data access. It will also send only requested information across the WAN.

Session analysis: A user-friendly tool will enable effective first-level problem analysis by customer-care staff (i.e., those who are less technically skilled). With easy access to GPRS/UMTS packet network activity, users will be able to gather information from all network interfaces and draw insightful conclusions about the when, where and why of a service failure. This capability is enhanced if the commercial solution com-piles historical data and also provides near-real-time troubleshooting capabilities.

Session tracing: An effective graphical user interface (GUI) can make this type of tool highly useful to ex-perts as well as less-skilled staff. For example, a pictorial sequence diagram of a subscriber session enables detailed analysis of signaling processes.

When these three essential capabilities are well integrated, the result is a significant improvement in opera-tional efficiency in the fault-management lifecycle.


An Example SolutionFor GPRS/UMTS packet data network operators, a comprehensive network and service solution should include the three key capabilities described in the preceding section: data management, session analysis and session tracing. JDSU Technologies offers a decentralized monitoring solution that provides a highly scalable architecture. It is especially effective at capturing user-plane information that is very useful in issue analysis and problem resolution.

Widely distributed customer care staff and technical personnel utilize a user-friendly GUI to access a central-ized application suite that is Web and Java enabled. Compared to traditional diagnostic solutions, this approach makes essential troubleshooting information readily available to a broader group of people.

A centralized application server is linked to JDSU servers installed in all monitored remote sites. The distrib-uted nature of the JDSU solution is illustrated in Figure 1.

ExternalStore Database

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Figure 1. The JDSU solution uses centralized and remote elements to enhance problem resolution.


An Example Solution (continued)The following overview is keyed to the numbered items in Figure 1:

A7 card cage:The card cage is used to monitor a variety of interfaces: Gn Sig, Gi Sig, IuPS, GboIP and GboFR. The solution can scale to meet growing traffic volume: Some installations are currently monitoring networks with traffic volumes that exceed 10 Gb/s.

The platform provides a carrier-grade monitoring solution, which gives operators the ability to perform end-to-end network and service analysis across multiple transport technologies. It extracts all signaling and user data directly from the signaling links using nonintrusive, failsafe technology, ensuring highly reliable network connectivity. It is also possible to extract signaling feeds directly from NEs. Signaling provides a source of data that is ideal for providing a unified network view and analysis, independent of NE type or vendor. The ultimate value of signaling is its capability to provide an independent analysis of network or service performance and activity.

Remote site servers:The monitoring of application data content and the generation of KPIs enables understanding of user behavior as well as service and application limitations within the core network and the radio access network (RAN). The JDSU solution captures application data on the Gn interface, which provides a very cost-efficient monitoring system based on standard industrial hardware.

The architecture is designed to handle high data rates, capture the data, create service usage records (SUR) and place a KPI summary of each application session into the transaction detail record (TDR) database. The solu-tion can correlate Iu, Gb, Gn and Gr captured messages, providing an end-to-end trace. For each session the JDSU solution can also create an xDR, which can be exported to third-party systems and used in data mining applications or real-time alarm dashboards.

Gigavue port aggregator:An existing Gigavue port aggregator can be used to route 10G input IP traffic to the remote site processor/IP probe and card cages. The aggregator also enables monitoring of Gb and IuPS over IP, and route the traffic to the A7 card cage or the RSP.

TDR store:To enable protocol analysis, the solution stores TDRs from IuPS, Gb, Gr, Gn Sig, Gi Sig and Gn user plane ser-vice usage records in the remote-site database.

Quality of Service Manager (QoSM) server: Aggregated measurements are sent from a remote site to the central sites QoSM database, which retains the data for 30 days.

Application server:This gives users a central access point to the key applications: Session Trace and QoSM.

Central server:Located in the central site, this server distributes system software and controls JDSU monitoring equipment located in remote sites.

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Identifying and Resolving Service IssuesThe following examples highlight the monitoring and troubleshooting tools that can help increase the like-lihood of first-call resolution, reduce the duration of support calls and enhance customer satisfaction. The screen shots are from the System Analyzer (SA) and System Trace (ST) components of the JDSU packet core monitoring solution. These tools make it easy for support staff to access the information they need to identify the root cause of a problem.

Example 1: A subscription problemA customer called the help desk to complain that he was not able to use any data services. A Tier 2 support engi-neer used Session Analyzer to access the database and extract the customers history for a specific time period. The user-friendly organization of the trace information made it easy for the support engineer to identify the problem. Here is what he found:

The user successfully connected to the network and was authenticatedThe handset settings were correct and the APN was validA quick look at the contract database verified that the user was allowed to use the service

After just two minutes of analysis the Tier 2 engineer was able to escalate the problem to a Tier 3 engineer. The Tier 3 engineer accessed the TDR database using Session Trace, which delivered detailed information that enabled him to understand the E2E signaling. He found the following:

A service request that included the parameters and a service reject with the causeThe Gr interface between the HLR and the SGSN showed that the requested APN was neither subscribed

nor enabled in the HLR database

To resolve the problem the operator needed to check the customers subscription status and verify that the HLR was correctly configured for this service. This is a typical example: An increasing number of problems can be solved or prequalified by the Tier 2 support organization. When needed, Tier 2 staff can quickly route a ticket to the correct Tier 3 organization, enabling faster resolution and lower support costs.


Identifying and Resolving Service Issues (continued)

Example 2: Unable to download a purchased ringtoneA customer called the help desk: He had purchased a ringtone but was unable to download it. A Tier 2 support engineer accessed the database to check signaling information and a summary of the user-plane information. This enabled a quick interim solution:

The user successfully connected to the network and was authenticatedThe handset was accessing the correct APNThe user was able to successfully access several websitesOne link was forbidden, causing the failure

The Tier 2 engineer sent the ticket to the application group for further analysis. He concluded the call by explaining the situation and crediting the users account.

The key to rapid resolution was the ability to analyze user-plane information from a highly loaded packet core network. This information is correlated with E2E signaling, accelerating the resolution process.


Identifying and Resolving Service Issues (continued)

Example 3: Inadequate throughputA customer called to ask why she was not getting the expected throughput rate. She was also concerned that her bill was much higher than expected because she had been using GPRS services very infrequently.

In addition to the signaling and user-plane information, the Tier 2 support engineer was able to view HTTP transactions: HTTP requests, number of bytes transferred, upload throughput, download throughput, latency, transmission path and more. This allowed him to verify the following details:

The handset, radio resources and cell ID were OKService requests, assigned radio resources and assigned maximum resources were OKRequested application services and the route and tunnel over which each service was transmitted were all

working correctlyThe number of downloaded bytes and the throughput rates

The investigation helped the support engineer eliminate the RAN and core network as contributors to the throughput problem; the wireless network was operating correctly. Because the problem was in the core IP network beyond the GGSN the call was transferred to a Tier 3 engineer in the IP transmission group for reso-lution. To address the bill shock issueand avoid excessive and unexpected downloads in the futurethe customer was advised to disable automatic updates from, for example, the operating system and any security applications when using the 3G dongle on her PC.


ConclusionIndustry forecasts suggest continued growth in the volume and complexity of data traffic carried on wireless networks. In this dynamic environment, customer satisfaction often depends on the ability to quickly identify underlying problems and successfully resolve support calls.

One essential tool is a highly scalable assurance solution that provides full-time monitoring and includes an integrated suite of monitoring and troubleshooting applications. As shown here, the monitoring of external network interfaces can provide an adequate and impartial view of the network by collecting signaling and user-plane information and using it to see whats really happening within the data network.

The JDSU packet core monitoring solution addresses surveillance, troubleshooting and long-term planning through speed, accuracy and insight. With JDSUs tools, network staff can easily access actionable information that will enable them to identify underlying problems, make informed decisions and, ultimately, improve cus-tomer satisfaction.

AAA authentication, authorization, and accountingAPN access point nameASP application service provider BICC bearer-independent call controlBSC base station controllerCAPEX capital expendituresCDMA Code Division Multiple AccessCLID calling line identificationCLIP calling line identification presentationDMT data mining toolkitESN electronic serial numberGGSN gateway GPRS support nodeGPRS General Packet Radio ServiceGUI graphical user interfaceHA home agentHLR home location registerHTTP hypertext transfer protocolIMSI international mobile subscriber

identityIP Internet protocolKPI key performance indicatorMGW media gatewayMSC mobile switching center

MSC-S mobile switching center serverMSS mobile softswitchNAI network address indicatorNE network elementOPEX operating expensesOLAP online analytical processingPCF packet control functionPDSN-FA packet data serving node, foreign

agentPDSN-HA packet data serving node, home agentPSTN public switched telephone networkQoS quality of serviceQoSM Quality of Service ManagerRNC radio network controllerSGSN serving GPRS support nodeSCTP Standard Control Transmission ProtocolSTP signaling transfer pointTDR transaction detail recordUMTS Universal Mobile Telecommunications

SystemURI uniform resource indicatorVIP very important personWAP Wireless Application Protocol

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Product specifications and descriptions in this document subject to change without notice. 2010 JDS Uniphase Corporation 30168032 500 0410 UMTS.WP.NSD.TM.AE April 2010

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White Paper: Maximize the Customer Experience with 3GPP Mobile Data Services

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