SHENZHEN, China -- With Huawei's support, HKT has recently completed VoLTE network migration, the most complex and difficult phase of the HKT-CSL network convergence project.
This migration is the first of its kind in the world and involves migration of IMS and CS domains, including the core 2G/3G/4G/IMS home subscriber server (HSS). Using only two days and without support from original device vendors, Huawei completed lossless migration of 2G/3G/4G CN and cutover of data of several millions of subscribes as well as VoLTE and CSFB services to its newly built CN. A key accomplishment was the signaling migration process, which lasted barely 2 minutes and remained unnoticed by most subscribers.
HKT had chosen Huawei in June 2015 to provide an end-to-end solution for HKT-CSL network migration. This decision was motivated by Huawei's future-oriented network evolution planning in conjunction with its carrier aggregation (CA), IMS centralized services (ICS), web real-time communication (WebRTC), and other cutting-edge products and solutions. The final factor in this decision was Huawei's extensive seamless migration and integration experience and long-term outstanding performance in the Hong Kong communications market.
HKT's acquisition of CSL has made it the largest operator in Hong Kong's wireless market, with an estimated share of over 40% and served several million 2G/3G/4G subscribers. The three biggest challenges became apparent: rapid network convergence without affecting subscribers, appropriate asset configuration, and OPEX reduction. Knowing that the CN is a key to network convergence, coupled with both years of experience in 2G/3G/4G CN and in-depth analysis of the call flow of all live CSL network services, Huawei proposed a lossless migration solution. The leading solutions provider worked with HKT to conduct successful PoC tests, proving feasibility and security of the solution. During the migration, Huawei used Mediation caching for service data updates from terminals and provisioning systems to migrate the 2G/3G/4G/IMS HSS without losses or external assistance. This success is reflected in a stably running CN with normal KPIs, including registration success, call completion, and call drop rate.