Why Did 5G Move to Service-Based Architecture?
In the evolution from 4G to 5G, one of the most fundamental and far-reaching architectural shifts is the transition from node-based architecture in the Evolved Packet Core, or EPC, to Service-Based Architecture, commonly known as SBA, in the 5G Core. For generations, mobile core networks were constructed around dedicated, monolithic network nodes. In 4G EPC, key functions such as the Mobility Management Entity, Serving Gateway and PDN Gateway each ran on purpose-built hardware with tightly coupled software stacks. Each node had a fixed, predefined role, and changes or upgrades typically required modification of the full node system. This rigid structure delivered stable performance for traditional mobile broadband and voice services, but it quickly showed its limits as the industry moved toward the far more diverse and dynamic 5G era.
