S1-U Uplink SGW Termination Point Switching in Dual Connectivity
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Solution Overview
Problem
Current dual connectivity operations in mobile communication networks, specifically in EPS systems, do not allow for seamless switching of S1-U uplink SGW termination points during or after bearer offloading from a Master eNB to a Secondary eNB, limiting the effectiveness of bearer split options like Alternative 1A.
Innovation Solution
A method and signaling flow that enables the switching of S1-U uplink SGW termination points by addressing information exchange between Mobility Management Entity (MME), Master eNB (MeNB), and Secondary eNB (SeNB), allowing for the update of user plane termination points during and after bearer offloading, using existing and new messages to propagate new addressing information for routing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If bearer offloading is performed from MeNB to SeNB in dual connectivity operation, then load balancing and resource utilization are improved, but the S1-U uplink SGW termination point cannot be switched seamlessly, causing routing inefficiency
Solution Approach 1:
The MME proactively provides the new S1-U uplink SGW termination point addressing information to the MeNB during the bearer offloading procedure, before the actual switching is needed. This preliminary provision of routing information enables seamless switching without subsequent complexity
Solution Approach 2:
The MeNB acts as an intermediary that receives the new SGW termination point information from the MME and forwards it to the SeNB. This intermediary role simplifies the overall system by centralizing the switching control in the MeNB while enabling the SeNB to use the new routing information
2Adaptability or versatility
If S1-U uplink SGW termination point switching is enabled during bearer offloading, then network flexibility and resource management are enhanced, but signaling complexity and procedure overhead increase
Solution Approach 1:
The switching of the S1-U uplink SGW termination point is merged with the existing bearer offloading procedure. The new SGW termination point information is provided within the same signaling flow used for bearer modification, eliminating the need for separate switching procedures and reducing overall signaling complexity
Solution Approach 2:
The bearer modification signaling procedure serves multiple functions: it performs the bearer offloading from MeNB to SeNB and simultaneously enables the switching of the S1-U uplink SGW termination point. This multi-functionality reduces the need for additional specialized signaling procedures
Data Source
AI summary
Methods and apparatuses are provided to facilitate switching of an uplink serving gateway termination point of a bearer that is offloaded from a master eNodeB (MeNB) to a secondary eNodeB (SeNB) in a dual connectivity operation. A signal is transmitted to the SeNB, via the MeNB, that includes addressing information of a new uplink serving gateway (S-GW) user plane termination point for the offloaded bearer. The addressing information is transmitted via the MeNB to the SeNB in a modification request message, such as an evolved radio access bearer (E-RAB) modification request message, and may include Internet Protocol (IP) addressing information and a Tunnel Endpoint Identifier (TEID).