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5g srvcc

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5G SRVCC (Single Radio Voice Call Continuity) is a feature that enables the seamless handover of voice calls from a 5G network to a 4G LTE or 3G network when necessary, ensuring that voice calls remain connected even when the user moves out of 5G coverage. This is crucial for providing a smooth and uninterrupted voice communication experience as mobile networks evolve from 4G to 5G.

Here is a technical explanation of how 5G SRVCC works:

  1. Initial Call Setup in 5G:
    • When a user initiates a voice call in a 5G network, the call is set up using Voice over New Radio (VoNR), which is the 5G voice service.
  2. Continuous Monitoring:
    • The 5G network continuously monitors the quality of the connection and the signal strength of the user's device.
  3. Handover Decision:
    • If the user moves to an area where 5G coverage is weak or unavailable, and the network determines that the call quality might degrade, the handover process is triggered.
  4. Interworking with Legacy Networks (4G/3G):
    • The 5G network communicates with the 4G or 3G network to establish the voice call on the legacy network seamlessly.
  5. Handover Execution:
    • The voice call is then handed over to the appropriate LTE (4G) or 3G network using the SRVCC mechanism. This involves coordinating the release of resources in the 5G network and activating the voice call on the legacy network.
  6. Codec and Protocol Adaptation:
    • The handover process may involve adapting the voice codec and protocols to ensure compatibility between the 5G and legacy networks.
  7. Voice Call Continuity:
    • The user experiences uninterrupted voice call service, even though the underlying network technology has changed from 5G to 4G or 3G.
  8. Data Synchronization:
    • Any relevant call state information, such as call duration, call ID, and other parameters, is synchronized between the 5G and legacy networks to maintain a consistent user experience.
  9. Handover Completion:
    • Once the handover is successfully completed, the 5G network releases the resources allocated for the call, optimizing its efficiency.
  10. Return to 5G:
    • When the user moves back into an area with sufficient 5G coverage, the system can initiate a handover back to 5G if necessary.

5G SRVCC is a critical feature for ensuring that voice calls remain robust and reliable as users transition between different generations of mobile networks. It leverages the strengths of both 5G and legacy networks to provide a seamless and consistent voice communication experience.