HP OpenCall GSM HLR is a solution that is independent of the type of switching equipment, and reduces operating costs by providing a universal interface for heterogeneous network elements. HP HLR solutions were the first in the market of subscribers information management systems in wireless networks.

HP OpenCall is a leader in mobility management solutions since 1993:

  • Synchronized mated-pair HLR (1993)
  • “No downtime” migration upgrade performed (1994)
  • Multi-switch vendor-compatible HLR (1994)
  • Integrated HLR/AuC (1995)
  • Multi-protocol HLR supporting both GSM and ANSI (2002)
  • More than 50% of the RnD cost goes to HLR functions development

HLR new generation – NextGen HLR – differ from traditional HLR. They do not work on the switching equipment, but the computer platforms, equipped with the appropriate software. HLR previous generation are not involved in the intensive evolution of standard PC hardware. They are designed for switching applications, and do not use a transactional database logic.

Deploying HLR for general purpose computing platform has several advantages, the main one – the number of records that may be stored in a single system. Among other benefits: reducing the number of managed systems in the network, reducing the amount of equipment (which simplifies maintenance and serves to satisfy the requirements of environmental safety), energy consumption, frequency of updates, number of interfaces between the various subsystems, as well as the number of staff.

Another advantage of the extended architecture is that it allows arbitrary scaling to meet changing conditions. This makes optimum use of the performance and capabilities of each processor to be added to the network. Introduction of new technologies of blade servers virtually eliminates the limitations on the number of subscribers that are stored in the HLR – number of records can be increased from less than 1 million to more than 100 million.

System hardware and software

HLR solution can be deployed on a hardware platform HP NonStop Server NS-series or NB-series.

HP Integrity NonStop Server – a server that belongs to the category of High-End. It is based on the use of HP NonStop Kernel operating system, ServerNet architecture and fully redundant elements, which ensures the highest levels of availability and fault tolerance. Integrity NonStop Server is ideal for the operation of the most critical business applications.

Technical Description

HP OC HLR solution is implemented on the basis of multi-tier architecture with no single point of failure that provides high availability. They distinguish the following levels:

  • The level of hardware (processors, adapters, peripherals)
  • The level of the operating system
  • The level of subsystems INS
  • The level of applications (apps)

Application-level modules implement logic of network elements for HLR (Home Location Register), AC (Authentication Centre), EIR (Equipment Identity Register), HSS (Home Subscriber Server). Processing of traffic destined for different entities (HLR, AC, EIR), is the same process (one software), which indicates the integration of applications into OpenCall HLR. HSS – a standalone application that runs on the same hardware platform as the HLR

Data about the keys AC (Ki) are contained in separate files and encrypted with storage-key, which are controlled by the security monitor.

Lower level subsystems provide applications.

INS subsystem (Intelligent Network Server) is used as an interface between the SS7 signaling network and top-level applications, and the HLR application

NSK (NonStop Kernel) operating system with multiprocessor hardware provides environment with high availability, reliability and fault tolerance for database management applications.

The system provides a highly reliable and scalable OLTP platform for deployment of mission-critical real-time applications.

For authorization and authentication in NSK subsystem safeguard is used, which provides flexible mechanisms of users security settings. User authentication uses a password, VPN tunnel to the trusted network is used to encrypt authentication. Also, you can access the system via ssh.

Solution architecture provides division of traffic processing (Front-End) and data storage (Back-End) on different servers.

Below is a diagram of HLR application subsystems.

Messages processing subsystem Node provides a scalable environment for continuous availability of business-critical real-time applications. Real-time processes, sending and receiving messages via MAP in and out of the network SS7, configured to run in the node environment. Overload control monitors the performance of the system overloads and is taking steps to ensure acceptable response times. Application processes discard statistics and reports on events that are handled by the collectors of statistics and information in the lower levels of the software architecture. ERAD subsystem for exception handling and alarm analyzes and displays events and alarms. The user interface (UI) provides access to the configuration data of INS subsystem. DPA (Dynamic Provisioning Architecture) provides components for reading and writing records to a database HLR, including the graphical user interface (GUI), a command line interface (CLI) and programming interface API, based on the architecture of CORBA. External interface for data changing EPI (External Provisioning Interface) provides the tools for client applications for sending read and write commands to HLR / AC (basically this facility is used for ANSI-41 stack and some of the features in GSM). To support the operation in the mated-pair configuration, subsystem ADS (Application Database Synchronization) provides a means of distributed database replication with data synchronization in real time. Security Monitor provides access to storage of keys protecting data authentication.

To integrate user data from the various network elements HLR has infrastructure for data management (separately licensed functionality), allowing to describe tables structure and profiles of subscribers. Thus, there is the opportunity to create a unified subscriber profile and a single point for data manipulation. It supports a variety of protocols for data management: telnet, LDAP, JDBC, ASCII over TCP (the so-called GMI-protocol – Generic Messaging interface), Diameter. SPR support is developed on the basis of this infrastructure.

Various utilities provide opportunities to read and change the HLR data, such as the mass scanning database or mass change with the ability to roll back the database to a previous state.

Advantages of HLR architecture

Среди основных преимуществ предлагаемого решения выделяются:

  • Reliability 99.99999%: reduces the chance of downtime to virtually zero
  • Ease of use: HLR has both an intuitive graphical interface for managing subscribers data and programming interface and a command line interface
  • Open interfaces for data management: uses an open architecture CORBA as a software interface
  • Security: provides user rights differentiation on different levels, including levels of applicationsl, database and individual fields
  • Flexibility to scale hardware and software upgrades: mated-pair architecture allows to expand the hardware platform and software components upgrades without downtime/li>
  • The object-oriented approach provides flexibility in developing applications and enables transparent migration mechanism

OpenCall HLR implementation experience has the following characteristics:

  • OpenCall HLR is the world’s first HLR, based on the server-side components
  • More than 200 million active subscribers served by the OpenCall HLR, established in CDMA, as well as in GSM / UMTS networks
  • More than 35 operators around the world use OpenCall HLR

More than 150 million customers migrated from traditional HLR to OpenCall HLR.