PDU Session in 5G/New Radio (NR) refers to a communication session established between a user's device (referred to as UE or User Equipment) and the 5G network's data network (DN). A PDU Session is essentially the logical channel through which data packets are transmitted from the UE to the DN, facilitating internet access, voice over new radio (VoNR), and other data services. The concept of a PDU Session in 5G is crucial for understanding how data connectivity is managed and maintained within the network.
Each PDU Session supports a specific type of network protocol, such as IPv4, IPv6, or both, and is identified by a unique session ID. This ID is important for managing and distinguishing between multiple sessions that a single device might have with the network simultaneously.
The establishment, maintenance, and termination of a PDU Session involve various network functions within the 5G architecture, including:
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AMF (Access and Mobility Management Function): Manages session mobility and ensures seamless connectivity as the UE moves.
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SMF (Session Management Function): Handles session management tasks such as session establishment, modification, and release.
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UPF (User Plane Function): Routes and forwards user data packets for the active PDU Session.
The PDU Session is a key component of the 5G network's service-based architecture (SBA), which enables flexible and efficient data service delivery. It allows for the deployment of multiple network slices, each catering to specific service requirements, ensuring that the network can meet diverse user and application demands.