Bearer Offload in Dual Connectivity via Local Gateway
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The dual connectivity feature in mobile communication networks, particularly for LIPA or SIPTO operations with a Local Gateway collocated with the HeNB, often results in degraded quality of service due to bearer offload from a Master eNB to a Secondary eNB, causing service interruptions and increased messaging that temporarily breaks user plane connectivity.
Innovation Solution
The solution involves transferring Gateway addressing information from the Master eNB to the Secondary eNB, allowing the Local Gateway to remain in the Master eNB while the data bearer is handled by the Secondary eNB, thereby enabling seamless bearer offload without service disruption, using signaling exchanges to route uplink and downlink traffic correctly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If bearer offload is performed from Master eNB to Secondary eNB in dual connectivity operation, then traffic handling capability is improved, but user plane connectivity is interrupted causing service degradation
Solution Approach 1:
The patent introduces a Local Gateway (L-GW) as an intermediary component that remains collocated with the Master eNB during bearer offload operations. This L-GW acts as a mediator that maintains the user plane connectivity between the UE and the core network while allowing the data bearer to be offloaded to the Secondary eNB. The L-GW receives downlink data from the core network and forwards it to the Secondary eNB, ensuring continuous connectivity without service interruption.
Solution Approach 2:
The patent segments the bearer handling functions by separating the control plane (remaining at Master eNB) from the user plane data transmission (offloaded to Secondary eNB). The Local Gateway is further segmented to handle only the user plane data routing, allowing independent optimization of each function. This segmentation enables the bearer to be offloaded to Secondary eNB for improved traffic handling while the L-GW maintains connectivity, resolving the contradiction between productivity and reliability.
2Productivity
If bearer offload is performed from Master eNB to Secondary eNB, then network resource utilization is improved, but messaging overhead with UE and Core Network increases
Solution Approach 1:
The Local Gateway serves as an intermediary that eliminates the need for frequent messaging between the Secondary eNB and both the UE and Core Network. The L-GW locally handles data routing and buffering, absorbing the messaging overhead and preventing it from propagating through the network. This allows efficient resource utilization through bearer offload while containing the complexity increase within the L-GW itself rather than increasing overall network messaging overhead.
3Adaptability or versatility
If Local Gateway is relocated during bearer offload, then bearer management flexibility is improved, but service continuity is degraded
Solution Approach 1:
The patent establishes the Local Gateway in advance at the Master eNB location before bearer offload occurs. This preliminary positioning of the L-GW ensures that when bearer offload is triggered, the gateway is already in place to maintain connectivity. The L-GW is pre-configured to handle user plane data routing, so when the data bearer is offloaded to Secondary eNB, service continuity is automatically maintained without requiring gateway relocation, thus achieving both flexibility and continuity.
Solution Approach 2:
The Local Gateway acts as a stable intermediary anchor point that remains fixed at the Master eNB while allowing flexible bearer management. The L-GW decouples the bearer management flexibility (ability to offload to different Secondary eNBs) from the gateway location, enabling adaptive bearer routing without service disruption. This intermediary approach allows the network to flexibly manage bearers while the L-GW ensures continuous service delivery.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An embodiment is a method for bearer offload from a RAN node referred to as Master RAN node such as Master eNB (MeNB) for E-UTRAN, to a RAN node referred to as Secondary RAN node such as Secondary eNB (SeNB) for E-UTRAN, in dual connectivity operation, wherein before said offload said bearer is or had been handled by said Master RAN node and involves a Local Gateway LGW collocated with said Master RAN node, said method including: - providing that after said offload said bearer is handled by said Secondary RAN node and involves said Local Gateway LGW collocated with said Master RAN node.