HSS (Home Subscriber Server)

What is HSS (Home Subscriber Server)?

A Home Subscriber Server is an all-inclusive management tool for subscriber data and includes subscriber information, device profile, and state information. It was created to support GSM, UMTS, LTE, IMS, WiFi, and IoT network mobility management, authentication, and authorization needs.

How does HSS work?

In HSS, the separation of signaling and policy is ensured via a central database of subscriber data. As a result, it aids CSPs in reducing the load on their data centers, enabling them to improve network efficiency and performance.

HSS enables CSPs to carry out specific tasks including blocking particular services and features, activating and deactivating SIM cards, and classifying users into hierarchical groups according to their subscriptions.

Background: The DIAMETER Protocol

In Long-Term Evolution (LTE) and IP Multimedia Systems (IMS) networks, Diameter is a next-generation industry-standard protocol used to send authentication, authorization, and accounting (AAA) data. In order to provide more dependable, secure, and adaptable transport methods for mobile data networks, it evolved from and improved upon the widely used RADIUS (Remote Authentication Dial-In User Service) and LDAP (Lightweight Directory Access Protocol) AAA protocols. The Policy and Charging Rules Function (PCRF), Home Subscriber Server (HSS), and Online Charging System (OCS) components of the LTE and IMS networks all make use of Diameter.

Sh Application

Sh is a DIAMETER interface between an Application Server (AS) and HSS. The operations supported by Sh interface include:

1. Data handling
2. Subscription and notification processes