HeNB Gateway S1AP Signaling Termination for Handover
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Solution Overview
Problem
The existing LTE system operations for Intra HeNBGW Inter HeNB handover face issues such as increased network and processing loads on the MME, double securing of network resources, and delayed timing of GTP tunnel switching, leading to pressure on network resources and potential errors in ensuring the order of Downlink User Plane Data transfer.
Innovation Solution
A base station gateway apparatus with C-plane and U-plane processing units that terminate or relay S1AP signaling and insert an end marker into U-plane data, allowing for immediate switching of the transfer destination from the source to the target base station, thereby reducing MME load and ensuring data order without relying on MME for resource management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If S1AP signaling is relayed to MME for Intra HeNBGW Inter HeNB handover, then handover control is maintained, but network load and processing load on MME increase
Solution Approach 1:
The patent extracts the handover control function from MME and relocates it to HeNBGW. The C-plane processing unit at HeNBGW terminates S1AP signaling locally and performs handover decisions without relaying to MME, thereby reducing MME load while maintaining handover control capability.
Solution Approach 2:
HeNBGW performs self-service by autonomously handling handover procedures. The C-plane processing unit independently manages S1AP signaling termination and handover control, eliminating the need for continuous MME involvement in intra-HeNBGW handovers.
2Reliability
If network resources are secured separately for source and target HeNB, then resource security is ensured, but network resources are doubly secured
Solution Approach 1:
The patent merges the resource management functions by having HeNBGW track both source and target HeNB resources centrally. The C-plane processing unit manages resource allocation for both HeNBs under unified control, eliminating duplicate resource securing while maintaining security.
3Device complexity
If GTP tunnel switching is delayed until handover completion, then resource allocation is simplified, but data transfer order cannot be ensured
Solution Approach 1:
The patent applies preliminary action by switching the GTP tunnel before handover completion. The U-plane processing unit performs tunnel switching in advance based on handover notifications, ensuring data transfer order is maintained while preparing resources ahead of time.
Solution Approach 2:
The patent ensures continuity by maintaining parallel data paths during transition. The U-plane processing unit continues forwarding data through the old tunnel while simultaneously establishing the new tunnel, ensuring uninterrupted and ordered data transfer throughout the handover process.
Data Source
AI summary
A disclosed base station gateway apparatus has a C-plane processing unit and a U-plane processing unit. When a mobile station performs handover from a subordinate source base station to a subordinate target base station, the C-plane processing unit terminates S1AP signaling received from the source base station and the target base station without relaying the S1AP signaling to a mobility management apparatus. The U-plane processing unit inserts, into U-plane data that is received from a serving gateway apparatus and that is to be transferred to the source base station, an end marker indicating that the U-plane data is the last data at a predetermined timing, and switches the transfer destination of the U-plane data, received from the serving gateway apparatus, from the source base station to the target base station at a timing immediately after the end marker is inserted.