Open Flow Controller for SIPTO Session Continuity
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Solution Overview
Problem
Current wireless communication systems, particularly LTE networks, face congestion and lack specifications for lawful interception and UE mobility during SIPTO, limiting the reduction of core network traffic.
Innovation Solution
The implementation of an open flow controller and network elements with open flow switches and flow tables to manage and divert data packets between core and local networks, enabling dynamic SIPTO and maintaining session continuity through secure tunnels and flow modification messages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If SIPTO is implemented to offload traffic from core network, then core network traffic is reduced, but session continuity during UE mobility is not maintained
Solution Approach 1:
The patent segments the network into local gateway nodes and core network nodes, with each maintaining separate flow tables. The local gateway handles local traffic offloading while the core network maintains session state, allowing traffic segmentation between local and core paths while preserving session continuity through coordinated flow table management during handovers.
Solution Approach 2:
The patent introduces a flow controller as an intermediary that coordinates between local gateway nodes and core network. The flow controller manages flow table modifications and ensures session state consistency during UE mobility, acting as a mediator that maintains session continuity while enabling local traffic offloading.
2Productivity
If local gateway is used for traffic offloading, then traffic can be diverted locally, but lawful interception capability is not provided
Solution Approach 1:
The flow controller acts as an intermediary that enables lawful interception by coordinating flow table modifications across local gateway and core network nodes. When interception is required, the flow controller modifies flow tables to redirect traffic through interception points while maintaining the ability to perform local offloading for non-intercepted traffic.
Solution Approach 2:
The patent implements dynamic flow table management where routing rules can be modified in real-time based on interception requirements. The system dynamically adjusts flow tables at local gateway and core network nodes to enable or disable interception paths while maintaining traffic offloading capability for other flows.
3Reliability
If flow tables are modified during handover, then session continuity is maintained, but system complexity increases
Solution Approach 1:
The flow controller serves as a centralized intermediary that manages flow table modifications during handover. Instead of each node independently managing complex flow table updates, the flow controller coordinates modifications across local gateway and core network nodes, simplifying the overall system architecture while ensuring session continuity.
Solution Approach 2:
The patent implements preliminary flow table setup where flow rules are pre-configured at local gateway and core network nodes before handover occurs. During handover, only specific flow table entries need modification rather than complete reconfiguration, reducing the complexity and time required for session continuity maintenance.
Data Source
AI summary
A communication system network element includes a Local Gateway co-located with a Home eNodeB. The Local Gateway has an open flow switch and a flow table, and provides service continuity of active SIPTO (selective IP traffic offload) sessions using open flow/software defined networking. An operator-controlled Open flow controller manages sessions at the Local Gateway. A flow modification feature is used to modify an existing flow in the flow table, which provides a means for interception and handover from a source Home eNodeB to a target Home eNodeB.