Subscriber Data Management (SDM) is the network function domain responsible for storing, managing, and providing secure access to subscriber identity, authentication credentials, and service profile data across mobile network generations. In 4G/LTE, this role was fulfilled by the Home Subscriber Server (HSS), a monolithic network function combining subscriber data storage, authentication, and mobility management into a single element. In 5G, the HSS is disaggregated into a set of discrete, cloud-native network functions — principally the UDM (Unified Data Management), UDR (Unified Data Repository), and AUSF (Authentication Server Function) — enabling operators to scale and evolve each capability independently. Across both generations, SDM forms the authoritative source of subscriber truth, underpinning every aspect of network access, authentication, and policy enforcement.
We use the following metrics the measure the SDM market:
The companies that are covered in the report include: