Home Subscriber Server – Korea Telecom

Altibase enables Korea Telecom to cope with problems with user authentication and authorization that undermines its IP multimedia subsystem. Altibase was chosen over Oracle TimesTen.

Use Case: Home Subscriber Server (HSS)

Current Customers: KT

Industry: Telecommunications


Korea Telecom (KT) is South Korea’s largest telecommunications service provider with over 40 million users. With deep wired and wireless expertise, KT has tremendous strength in fiber optics, digital multimedia services and both wired and wireless broadband services.


KT sought a reliable, real time solution for its core Home Subscriber Server (HSS) functionalities that included mobile management, user authentication, security and service processes.

  • The growing demand of its 40 million customers utilizing the company’s IP multimedia core network subsystem rendered KT’s legacy database obsolete.
  • The intrinsic complexities of HSS strained KT’s legacy on-disk databases, resulting in excessively high usage of system resources, increased failure points and prolonged latency.
  • KT needed a comprehensive solution that could easily handle over 1 million subscribers with numerous concurrent authentication and authorization attempts.
  • KT also required a database solution that would be able to handle user growth and absolute growth in multi-device demand.


Altibase has been deployed as the core database for KT’s HSS services after beating Oracle TimesTen in a benchmark test in 2012. Altibase’s in-memory feature has helped KT with seamless management of all related HSS requirements while creating a robust foundation for KT’s future growth.


  • Altibase arms KT with the ability to authenticate up to 100 million times per day, future-proofing the company’s ability to handle growth.
  • Altibase allows for performance enhancement over the legacy system by multiples.
  • KT noted that factors for Altibase deployment over Oracle TimesTen were:
    1. Altibase excelled in overall performance and especially in complex queries.
    2. Altibase’s data durability in system failure situations was more stable.
  •  Altibase is now used as the core database for many of KT’s other mission critical systems.

Home Subscriber Server

Altibase – Downloading is Believing.