Home Subscriber Server (HSS)

Description: The HSS is the central subscriber database. It stores permanent, sensitive user data, often referred to as the “single source of truth.” This includes:

• User Identification (IMSI, MSISDN)
• Authentication Credentials (K key, OPc/OPS, K4)
• Subscription Profile (Subscribed APNs, default QoS parameters)
• Dynamic Information (Current serving MME)
• Context & Deployment: The WebUI provides a straightforward way to add, edit, and delete subscribers. The HSS performs authentication using the MILENAGE algorithm, generating vectors (RAND, AUTN, XRES, KASME) that are sent to the MME to challenge the UE.
• Interfaces: S6a, Cx, and SH