Traffic Offloading via ANDSF Mediator for LTE-WLAN Steering

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Solution Overview

Problem

Current wireless communication systems face limitations in efficiently offloading traffic between cellular networks and WLANs due to restricted support for radio network conditions, which hampers the ability of operators to favor specific radio access technologies over others, leading to suboptimal bandwidth usage and limited flexibility in traffic steering.

Innovation Solution

The implementation of techniques that allow user equipment (UE) to determine and adapt to available network capabilities by evaluating RAN rules, ANDSF policies, and network quality measurements to decide on traffic offloading between LTE and WLAN networks, using RAN assistance information and enhanced ANDSF configurations to optimize traffic routing based on thresholds and restrictions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If traffic offloading is implemented between cellular and WLAN networks, then bandwidth usage efficiency is improved and network flexibility is enhanced, but device complexity increases due to multiple network interface management and policy evaluation

Engineering Contradiction:
Improvebandwidth usage efficiencyVSAvoiddevice complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent introduces an access network discovery and selection function (ANDSF) as an intermediary component that mediates between the UE and multiple access networks. The ANDSF stores and manages offloading policies, evaluating RAN rules and network conditions to determine optimal traffic routing decisions. This mediator handles the complexity of multi-network management, allowing the UE to offload traffic efficiently without bearing the full burden of policy evaluation complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If RAN rules and ANDSF policies are used for traffic steering, then network flexibility and traffic management capability are improved, but the difficulty of detecting and measuring network conditions increases

Engineering Contradiction:
Improvenetwork flexibilityVSAvoiddifficulty of detecting and measuring
Core Design Contradiction:
Adaptability or versatilityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent segments the network condition detection and evaluation process into distinct functional components. The ANDSF separately manages RAN rule evaluation, WLAN condition assessment, and policy decision-making. This segmentation allows each component to focus on specific measurement tasks (cellular signal quality, WLAN availability, traffic flow characteristics) without overwhelming complexity, enabling flexible traffic steering while maintaining manageable detection and measurement procedures.

Inventive Principle:
Principle #1Segmentation

3Adaptability or versatility

If multiple access networks are supported for traffic offloading, then adaptability and network selection capability are improved, but ease of operation decreases due to complex policy configuration and management

Engineering Contradiction:
ImproveadaptabilityVSAvoidease of operation
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The ANDSF implements self-service functionality by automatically evaluating RAN rules, assessing current network conditions, and making policy-based decisions without requiring manual intervention. The system autonomously determines when to offload traffic to WLAN or keep it on cellular networks based on pre-configured policies and real-time measurements. This automation maintains high adaptability while significantly improving ease of operation by eliminating the need for users to manually configure complex multi-network policies.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3432634B1Methods and devices for traffic offloading
Publication Date: 2021.02.17 APPLE INC
  • EP3432634B1 patent drawingFigure 1
  • EP3432634B1 patent drawingFigure 2
  • EP3432634B1 patent drawingFigure 3

AI summary

Wireless communication traffic can be offloaded from a user equipment (UE) to two wireless points of access. For example, user equipment (UE) is connected to a radio access network (RAN) using a radio access technology (RAT) such as a long term evolution (LTE) network. The UE can determine which network capabilities are available for traffic offloading and adapt to the capabilities presented. In one embodiment, the UE can determine whether the network supports three different configurations and configure traffic offloading to operate within the network conditions: (1) RAN rules without access network detection and selection function (ANDSF), (2) ANDSF in conjunction with RAN rules or (3) enhanced ANDSF with RAN assistance.