Sign in Subscribe

5g vonr call flow

Last updated on 

Voice over New Radio (VoNR) is a technology that enables voice services over the 5G network. It is designed to provide high-quality voice communication over the 5G infrastructure. Here's a detailed technical explanation of the VoNR call flow:

  1. UE (User Equipment) Registration:
    • The User Equipment (UE), which is the mobile device, initiates the registration process with the 5G core network (5GC).
    • The UE sends a Registration Request to the 5G Core Network (5GC).
  2. Network Registration:
    • The 5GC processes the Registration Request and validates the UE's identity.
    • If the UE is authenticated and authorized, the 5GC registers the UE and allocates the necessary resources for communication.
  3. Bearer Establishment:
    • The 5GC establishes a data bearer for the UE. This bearer is used for both signaling and user data.
  4. Initial Access and Cell Selection:
    • The UE performs initial access and selects a suitable cell in the 5G radio access network (RAN).
    • The UE establishes a connection with the selected cell and acquires synchronization.
  5. RRC Connection Establishment:
    • The Radio Resource Control (RRC) connection is established between the UE and the gNB (5G New Radio Base Station).
  6. VoNR Call Setup:
    • The UE initiates a VoNR call by sending a VoNR Session Establishment Request to the 5GC.
    • The 5GC processes the request and establishes a VoNR session with the UE.
  7. VoNR Session Configuration:
    • The 5GC configures the necessary parameters for the VoNR session, including codec selection, security parameters, and Quality of Service (QoS) settings.
  8. Initial IMS (IP Multimedia Subsystem) Registration:
    • The UE performs an initial registration with the IMS to enable voice services.
  9. VoNR Call Establishment:
    • The 5GC initiates the establishment of the VoNR call by signaling the gNB.
    • The gNB allocates radio resources for the VoNR call.
  10. VoNR Data Transmission:
    • Voice data is transmitted over the established VoNR session between the UE and the 5GC.
  11. Voice Codec Negotiation:
    • The UE and the 5GC negotiate the codec parameters for the voice call, ensuring compatibility and optimal voice quality.
  12. IMS Call Setup:
    • The IMS initiates the call setup procedures to connect the call to the recipient.
  13. VoNR Call Termination:
    • When the call ends, the 5GC releases the resources allocated for the VoNR session.
  14. IMS Call Termination:
    • The IMS releases the resources associated with the voice call.
  15. UE Deregistration:
    • The UE deregisters from the 5GC when it moves out of the coverage area or when the user turns off the device.

This is a simplified overview, and in a real-world scenario, there are additional complexities and optimizations, such as handovers, security procedures, and network optimizations, that may come into play during the VoNR call flow in a 5G network.