SRVCC Call Control Node for Seamless CS to LTE Handover

The patent implements dynamic handover capability that allows calls to switch between CS and PS access based on network conditions and UE capabilities. The system maintains flexibility by enabling return from CS to PS access through dynamic bearer management and context transfer mechanisms, rather than following a fixed one-way handover path.

The patent performs preliminary actions by establishing PS bearers and maintaining UE context information before actual handover execution. The network prepares the target PS access resources in advance, ensuring that when return handover is needed, the transition can occur seamlessly without service interruption.

The patent introduces intermediary mechanisms including the serving gateway and PDN gateway that maintain PS domain context and bearers even when the call is active in CS domain. These intermediaries enable the call to be transferred back to PS access by coordinating between CS and PS network elements, acting as a bridge that preserves service continuity.

The patent replaces the traditional mechanical one-way handover mechanism with a software-based context management system. Through SIP signaling and bearer context transfer, the system can logically switch between CS and PS access without physical reconfiguration, enabling seamless return handover while maintaining call stability.

The patent implements universal handover capability where the same network elements (MME, serving gateway, PDN gateway) can handle both PS to CS and CS to PS handover directions. The system uses unified context management and bearer handling mechanisms that work bidirectionally, making the handover function versatile rather than direction-specific.

The patent performs preliminary setup of PS domain resources and maintains UE context information before handover execution in either direction. By preparing the target access resources in advance and maintaining flexible bearer contexts, the system enables reliable return handover from CS to PS without requiring separate dedicated mechanisms for each handover direction.