Here are some of the key call flows in the EPC:
Maintains the user data flow when the UE moves between different eNodeBs. D. P-GW (PDN Gateway)
These nodes work together through standardized interfaces and protocols to ensure robust, secure, and efficient mobile broadband services. Here are some of the key call flows
: The primary control-plane node. It handles session states, authenticates users via the HSS, tracks user equipment (UE) locations, and manages the connection and release of bearers.
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The MME queries the HSS to authenticate the subscriber identity (IMSI) and establishes NAS (Non-Access Stratum) security keys to encrypt further control signaling.
Once the UE acknowledges the setup, the eNodeB sends an Initial Context Setup Response to the MME containing the downlink S1-U TEID (Tunnel Endpoint Identifier). The MME completes the loop by sending a Modify Bearer Request to the S-GW, cementing the permanent uplink/downlink user plane tunnels. 2. Dedicated Bearer Activation This link or copies made by others cannot be deleted
When a user opens an application requiring guaranteed throughput (like initiating a VoLTE call), a dedicated bearer is dynamically established.