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KPN—A Pioneer of the All IP Network (PDF-618K)

--Huawei Service Migration Solution Helps KPN Realize Network Transformation

With the rapid development of communication technologies, such as 3G mobile communications, All IP, IMS and FMC, carriers all over the world face the challenge of transforming their networks and providing new services in the increasingly competitive global telecommunication market. For KPN, the Dutch telecommunications company, the challenge was even greater. To maintain its dominant position in the market, in 2005 KPN acquired TELFORT, another telecom carrier in the Netherlands. Due to this market share expansion, KPN's mobile network became increasingly complex. There were two 2G and two 3G core networks, constructed in different periods by three different suppliers, which were located in the network top layer, as shown in Figure 1-1. 

Figure 1-1 Mobile core network after KPN acquired TELFORT

The coexistence of several mobile core networks results in too many switches and too much transmission. With the increase of traffic and the development of the 3G data service in the future, this can lead to network congestion and communication quality degradation. To handle these problems, carriers must invest more to construct fiber transport and data bearer networks, operate several network management centers, to manage and monitor the network, and need the support from several suppliers for equipment maintenance and spare parts management. Doubtlessly, these measures lead to an increase in CAPEX and OPEX. Thus, the operational pressure for KPN was considerable.

The critical issues for KPN were:

• How to integrate several existing core networks
• How to expand the network in the future.
• How to enable the network to provide rich IP services.

After consultations and discussions with several equipment suppliers, KPN decided to transform the mobile core network and optimize the network architecture.

KPN is extremely cautious in choosing partners and schemes. However, Huawei provides the industry-leading mobile softswitch solution and the complete Huawei service migration solution. In addition, Huawei offers excellent cooperation to TELFORT and KPN in the Netherlands. Considering these factors, KPN finally chose Huawei as its strategic partner. KPN will replace its traditional core network equipment with the core network equipment of Huawei, establishing an All IP mobile core that supports the convergence of 2G and 3G. Figure 1-2 shows the mobile core network of KPN after the network transformation.

Figure 1-2 KPN mobile core network after the migration 

"KPN is happy to have chosen a new strategic partner which is one of the leading telecom manufacturers in China. KPN expects this partnership may lead to more successful projects."

— Eelco Blok, Corporate Strategy & Innovation Officer of KPN

After the partner and scheme were selected, the project entered the implementation and delivery stages. More than 80 KPN staff from different departments participated in this project. To ensure efficient and smooth communications, Huawei established the parallel organization and communication mechanism for the KPN project. Figure 1-3 shows the relationship between departments of KPN and Huawei.

Figure 1-3 Organization structure for the KPN-Huawei project

The requirements of the research and project design in the early stages are very important, as this determines the timely delivery and project quality. To satisfy the requirements from KPN, Huawei dispatched CS/PS/OSS marketing, research and development experts and established a project requirement research and analysis team in the Netherlands. The experts communicated with KPN engineers actively and participated in all of the research workshops with KPN and the third-party vendors to provide relative technical solutions and suggestions. Huawei accomplished the following tasks:

• Identified and clarified more than 50 KPN service requirements.
• Ensured the smooth transition of the existing network services.
• Customized the network migration scheme and N+1 network recovery evolution scheme for KPN.
• Provided a solution that satisfied 100% of KPN's requirements.

Project implementation：

In order to make the service run normally and shorten the service interruption time, the whole migration project was scheduled into two stages. In the CS domain it was as T/GMSC at the first stage and as VMSC at the second stage. In the PS domain cut over 132 BSC at the first stage and 12 RNC at the second stage.

The M2000 network management system was migrated to the network in November, 2006. The migration involved the interconnection with several northbound NMSs. Despite many difficulties in the process of requirement research and testing, the M2000 was successfully migrated to the network within 7 months, including requirement research,.design,.development and cutover.

In the first stage, the CS domain and PS domain were migrated to the network at the end of 2006. In the second stage there were 132 BSCs and 12 RNCs that were required to be cutover in the CS domain terminal office.16 VMSCs and 1100 E1s were required to be replaced. By means of strict system testing, the cutover process went very smoothly. Although some small problems occurred occasionally, the system became very stable and worked properly within the stipulated time with the joint effort of the KPN and Huawei engineers.

Highlights in the Migration Process

At the initial stage of the project, 1+1 network backup scheme was adopted based upon the CS domain. While for a better disaster recovery solution, the personnel adopted the N+1 scheme instead, which ensures that in case of network problems the services can be switched to the backup system both automatically and manually. In the process of migration, except for the STP, no third-party network element (NE) was affected, reducing the KPN coordination effort. The operation time for each command was as precise as one second. The service interruption duration was controlled to within 20 minutes. Given that the N+1 scheme, based on the CS domain, was applied in Europe for the first time, the personnel discussed and simulated the conditions several times, in terms of network recovery. Finally Huawei personnel upgraded the 1+1 scheme to the N+1 scheme based upon the actual network conditions of KPN.

Winning at the Beginning—version testing

In the process of delivery, the schedule was very tight. As required by KPN, the test items were many and all software versions and patches had to be tested on the Testbed before being configured into the network. In Phase 1, 389 cases were tested, and 1,190 in Phase 2. In addition, the requirements on tests were extremely strict.

All scenarios must be covered.

The verification result must be precise (message tracing and CDR verification).All differences between the information element processing of the new switch and that of the old switch must be recorded to the Problem Record (PR) for tracing and handling, even if the service is normal.

The modification control for the version and data is strict. All data modification must have official Modification Record (MR). 

After the data was modified or the patch was loaded, the regression test had to be performed. 

The two phases and the later regression test needed 10 months to complete.

To guarantee the timely delivery, after internal discussions, the project team decided that the Huawei personnel perform the tests jointly with the KPN engineers in the early stages. After Huawei's skilled personnel gained the trust of KPN, the tests were performed independently. Relative message processes and screen copies were saved as evidence to prove that the test was passed. After this scheme was approved by KPN, the test progress was completed on time, making a solid foundation for the timely delivery of the whole project.

Customizing the Scheme and Ensuring the Quality

KPN required that, after the cutover, the KPIs of the whole network must be the same as that of the previous network and all services cannot be interrupted. This is the standard to judge whether the network cutover is successful. Huawei designed a specific cutover scheme and carried out a lot of preparations to guarantee the quality of the cutover. For example, the 3G cutover scheme was verified for one week in the Testbed and three rollback schemes were prepared. For the PS domain, it is reasonable for the KPN to require that the KPIs of the network must be the same as that of the previous network because it was the complete equipment replacement. For the CS domain, on the contrary, the network structure was changed and the signaling process was added because in Phase 1 the GMSC and TMSC replaced the VMSC. Thus, the KPI may be affected. To meet the requirements from KPN, we requested KPN to conduct a whole network test and provide relative indices of the existing network. After learning the KPI of the existing network and comparing the KPI that Huawei achieved in other projects, we formulated a specific scheme to ensure that the KPI after the cutover is equal to, or better than, that of the previous network. For the PS domain, after the cutover, all the KPIs were the equal to, or better than, the KPI of the previous network. For the CS domain, only the indices of voice quality and delay are a little different from that of the previous network. This is inevitable because the transmission media was changed. All the other indices were normal. KPN was satisfied with the results and the OAT was passed successfully.

Figure 1-4 shows some indices of KPN after the cutover.

Excellent Performance in Handling the New Year Heavy Traffic

Every year in the Netherlands, the traffic reaches a peak on New Years Day. On the New Years Day of 2007, Huawei engineers worked with KPN O&M managers and engineers in the equipment room, instead of celebrating the New Year with their friends and colleagues. The traffic was ten times that of the usual traffic that night. The performance of Huawei core network equipment was excellent, enduring the heavy traffic.

With the cooperation of the KPN team, the team of Huawei successfully completed the migration project. This project simplified the KPN network architecture, enhanced the security and stability of the network, increased the QoS of the network and reduced the OPEX by a large margin. Especially in CS domain, 9 MSC servers and 10 MGW of Huawei replaced nearly 40 sets of core network equipments (6 MSC services, 6 MGW, 24 VMSC), reducing the number of sites from 5 to 12. Since the number of equipment and sites was largely reduced, costs of billing and power consumption were consequently saved and at the same time the maintenance efficiency was improved.

After the successful delivery of Phase 1, KPN praised the hard work and professional skill of the Huawei project delivery team. 

"We are very happy that the project to replace KPN Mobile core network with the future proof Huawei core network is well on track. Huawei has shown their ability to supply European tier one operators and deliver in time a network with outstanding QoS performance that will benefit KPN and Telfort's end customers. We are very pleased to see that the KPN Mobile network is now ready for the future, mainly based on the efficient IP protocol."
— Sietse Sijperda, former CTO of KPN Mobile

At present, the Phase 2 migration work is in the process of implementation. It is scheduled to be completed in the first quarter, 2009. By then, KPN will have a state-of-the-art and future proof network with high capacity. This will allow KPN to deploy next generation, IP-based, services flexibly and realize the first IP network transformation for large scale commercial use in Europe.
Background

Located in the western part of Europe, the Netherlands is famous for its tulips and windmills. KPN Telecom N.V. is the largest mobile and fixed network carrier in the Netherlands. KPN ranked 494th in the World's Top 500 Enterprises in 2007 and ranked 16th in the Global Telecom Operators. KPN employs 30,000 staff and has annual revenues of 12 billion euros. It is one of the top ten telecom carriers who are worth investing in. In 2006, KPN has served 6.9 million fixed line subscribers and 2.2 million Internet users, in Netherlands, and 20.8 million mobile subscribers in Netherlands, Germany, and Belgium.