VoLTE is a technology that allows voice calls to be made over the LTE network using an all-IP framework, replacing traditional circuit-switched calling. It offers high-definition voice quality, faster call setup, and allows simultaneous use of voice and data services.
How VoLTE Works: Call Flow
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Call Setup: The user equipment (UE) registers with the IMS core using SIP to initiate the call.
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Media Transport: Voice is transmitted using RTP over the LTE data channel.
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Call Handover: If LTE signal weakens, the call is handed over to 3G via SRVCC.
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Call Termination: The session ends when either party disconnects.
Advantages
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High-definition (HD) voice quality
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Simultaneous voice and data usage
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Faster call setup times
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Lower call drop rates
Challenges
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Requires LTE network coverage
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Works only on VoLTE-capable devices
This makes VoLTE an essential component of modern mobile networks, especially in LTE and 5G deployments.