QoS Mapping Mechanism for Inter-RAT Handover Continuity
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Solution Overview
Problem
Current mechanisms for handling non-guaranteed bit rate (non-GBR) bearers and quality of service (QoS) parameters during inter-radio access technology (RAT) handovers in wireless telecommunications systems often result in service disruptions due to incompatibilities between different radio access networks, particularly between E-UTRAN and UTRAN/GERAN technologies.
Innovation Solution
A standardized mechanism for QoS mapping is introduced to manage non-GBR user agent (UA) aggregated maximum bit rate (AMBR) and access point name (APN) AMBR during handovers, ensuring continuity by mapping AMBRs and MBRs across different networks, allowing for proportional or varying allocations based on active bearers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If current mechanisms for handling non-GBR bearers and QoS parameters during inter-RAT handovers are used, then service continuity is maintained in simple scenarios, but service disruptions occur due to incompatibilities between different radio access networks in complex inter-RAT handover scenarios
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting QoS parameters (AMBR and MBR) during inter-RAT handovers. The source access network determines appropriate MBR values for non-GBR bearers based on the target network's capabilities and current network conditions, transforming the QoS parameter set to ensure compatibility across different radio access technologies while maintaining service continuity
Solution Approach 2:
The patent introduces an intermediary mechanism where the source access network acts as a mediator during handover preparation. It calculates and determines the MBR values for non-GBR bearers before handover execution, serving as an intermediate step that bridges the QoS parameter systems of different radio access networks and prevents service disruptions
2Reliability
If standardized QoS mapping mechanism is implemented to ensure QoS continuity during inter-RAT handovers, then service disruption is reduced, but signaling complexity and processing overhead increase
Solution Approach 1:
The patent applies preliminary action by performing QoS parameter determination during the handover preparation phase rather than during execution. The source access network determines MBR values for non-GBR bearers in advance by receiving handover preparation messages and calculating appropriate parameters before the actual handover occurs, thereby simplifying the execution phase while ensuring QoS continuity
Solution Approach 2:
The patent segments the QoS handling process into distinct phases: handover preparation (where MBR determination occurs) and handover execution. By separating these functions and assigning the complex QoS mapping operations to the preparation phase, the patent reduces processing complexity during critical handover execution while maintaining reliable QoS transitions
Data Source
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AI summary
A method for quality of service (QoS) parameters mapping during a handover from a first radio access network (RAN) (source RAN, 104) to a second RAN (target RAN, 106), the first RAN having communication with at least one access point name (APN), comprising: deriving an APN aggregated maximum bit rate (APN-AMBR) based on a maximum bit rate (MBR) of a packet data protocol (PDP) context associated with a first APN of the first RAN (104); providing a local user equipment (UE) aggregated maximum bit rate (UE-AMBR) until a subscribed UE-AMBR is available for the UE,- acquiring the subscribed UE-AMBR,-calculating a derived UE-AMBR by taking the minimum of the subscribed UE-AMBR and the sum of all APN-AMBRs of all active APNs associated with the UR; comparing the derived UE-AMBR to the local UE-AMBR; and initialing a subscribed quality of service (QoS) modification procedure to notify the derived UE-AMBR if the local UE-AMBR is different from the derived UE-AMBR.