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5g data call flow

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The 5G data call flow involves several steps and entities to establish a communication session between a user device (UE - User Equipment) and the 5G core network.

Here's a technical explanation of the 5G data call flow:

  1. Attach Procedure:
    • UE Attachment Request: The user equipment initiates the attach procedure by sending an attach request to the 5G core network (5GC).
    • Authentication and Security Setup: The 5GC authenticates the UE and establishes security between the UE and the network using the Authentication and Key Agreement (AKA) protocol.
  2. Registration:
    • UE Registration: The UE registers with the 5GC, providing information about its capabilities and current location.
  3. PDU Session Establishment:
    • Service Request: The UE requests the establishment of a PDU (Packet Data Unit) session for data transfer.
    • Access and Mobility Management (AMF): The AMF in the 5GC is responsible for managing mobility-related functions.
  4. Session Management:
    • SM Context Setup Request: The 5GC initiates the setup of the Session Management (SM) context, including the selection of the Access and Mobility Management Function (AMF) and the setting up of QoS (Quality of Service) parameters.
    • SM Context Setup Accept: Once the SM context is set up, the 5GC sends an acceptance message to the UE.
  5. Data Transfer:
    • Data Transfer Request: The UE sends a data transfer request to the 5GC, indicating its intention to send or receive data.
    • Data Transfer: The actual data transfer occurs over the established PDU session. The data may traverse the 5G New Radio (NR) access network.
  6. Release Procedure:
    • UE Initiated Release: The UE may initiate a release procedure if it wants to terminate the PDU session or detach from the network.
    • Release Complete: The network acknowledges the release, and resources are released.
  7. Handover (Optional):
    • Handover Preparation: If the UE moves to an area served by a different cell or gNB (gNodeB), the handover procedure is initiated.
    • Handover Execution: The data session is handed over to the target cell, ensuring continuity of the session.
  8. Session Termination:
    • UE Initiated Session Release: The UE may initiate the release of the PDU session when the data transfer is complete.
    • Session Release Complete: The network acknowledges the release, and resources are released.