Subscriber databases are key elements of any mobile network. Evolution from classical telecommunication networks to current mobile networks has changed their architecture and also services they provide. New functionalities are required and they should fulfill more complex tasks.
Evolution from GSM network through UMTS and LTE to the newest technology IMS is happening nowadays. This trend includes evolution from home location register (HLR) and authentication center (AUC) to home subscriber server (HSS) and introduction of new unified storage architectures like SDM.
Classical networks usually have several subscriber databases distributed through the nodes, such as:
- HLR – Home Location Register
Is a database used for storage and management of subscriptions 2G and 3G. The HLR is considered the most important database, as it stores permanent data about subscribers, including a subscriber service profile, location information and activity status. When a person buys a subscription in the form of SIM, then all the information about this subscription is registered in the HLR of that operator.
- AUC – Authentication Center
Is a protected database, usually collocated with HLR node, which stores a copy of the secret key stored in each subscriber’s SIM card, which is used for authentication and ciphering of the radio channel. The AUC protects network operators from different types of fraud found in today’s cellular world.
- HSS – Home Subscriber Server
Is a database that contains LTE (4G) user-related and subscriber-related information. It also provides support functions in mobility management, call and session setup, user authentication and access authorization.
It is based on the previous HLR and Authentication Centre (AUC).
- MNP – Mobile Number Portability
Enables consumers to retain their mobile numbers when changing service providers in the same country. It can be implemented using either decentralized database or centralized database approach. Decentralized database solution requires each operator to maintain its own number portability database, as it is deployed in Spain.
- EIR – Equipment Identity Register
Is a database that contains a list of all valid mobile equipment on the network, where its International Mobile Equipment Identity (IMEI) identifies each mobile phone. An IMEI is marked as invalid if it has been reported stolen or is not type approved.
- PCRF – Policy Control and Charging Rules Function
Is a component which is not shown in the above diagram but it is responsible for policy control decision-making, as well as for controlling the flow-based charging functionalities in the Policy Control Enforcement Function (PCEF), which resides in the P-GW.
With the solution of unified storage architectures, data from many incompatible and proprietary databases is consolidated into a single repository. The data is shared between multiple applications like 3GPP HSS, HLR, AAA, EIR, MNP or 3rd parties, not duplicated for each one. Since there is only one copy of each piece of data, with a common definition, there can be none of the inconsistencies and ambiguities that inevitably arise otherwise.
In the traditional silo approach each new service requires a new application with own database. That database needs to be put into a highly available architecture, integrated with a new interface into the provisioning systems and appropriate maintenance processes need to be set up. With unified storage architectures solution, only a simple extension to the central repository’s data model and the already established provisioning interface is required. As a result, new services can be introduced much faster afterwards.
There is an even greater gain in speed when activating customers. In the traditional approach, this activation requires a sequence of actions for each separate application. A failure in any one can cause the whole sequence to be reversed, or to be left in an incomplete and inconsistent state. With new solutions, there is just one real-time provisioning interface to be touched to perform activation and verify it immediately. Customers can instantly use their services.
Benefits and Conclusion
New unified solution is designed for telecommunication operators from scratch, comprising extreme high availability and reliability together with fastest speed and performance. Data is shared in real-time between several sites; each site is always active and always has the latest data. If any site is incapacitated or becomes disconnected from the network, the full load is instantly and automatically carried between the remaining sites.
New subscriber databases support multiple applications from third parties, operators and different vendors. It works with any standard industry domain and technology including CS, PS, EPS or LTE. Bringing all subscriber data into a single repository simultaneously ensures a reliable, real-time view of the entire end-user – a customer view rather than an application view – and it significantly reduces the costs of managing the data.