Base Station SCG Change IP Packet Forwarding Without Flow ID
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Solution Overview
Problem
Current technologies face challenges in seamlessly switching connectivity between base stations in dual connectivity scenarios, leading to incorrect decoding of IP packets due to the inclusion of flow IDs in PDCP SDUs when forwarded between different radio bearers.
Innovation Solution
Implementing a system where base stations control the forwarding of IP packets without flow IDs during SCG changes, ensuring that only the IP packets are transmitted between base stations, thereby avoiding incorrect decoding and enhancing seamless connectivity changes for user equipment in dual connectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If base stations forward PDCP SDUs containing flow IDs during SCG change, then data transmission continuity is maintained, but IP packets are incorrectly decoded due to flow ID inclusion
Solution Approach 1:
The patent segments the PDCP SDU into two parts: the flow ID portion and the IP packet portion. During SCG change, only the IP packet portion is forwarded between base stations, while the flow ID is handled separately by the UE. This segmentation resolves the contradiction by preventing flow ID inclusion in forwarded packets (avoiding decoding errors) while maintaining data transmission continuity through proper flow ID management at the UE side.
Solution Approach 2:
The patent extracts the flow ID from the PDCP SDU before forwarding between base stations during SCG change. The flow ID is removed from the packet transmission path between base stations, and the UE is configured to handle flow ID mapping separately. This extraction eliminates the cause of incorrect IP packet decoding while preserving data transmission continuity through the extracted flow ID information being maintained in the UE's flow context.
2Loss of information
If base stations forward complete PDCP SDUs including flow IDs, then data flow identification is maintained, but connectivity switching between base stations becomes incorrect
Solution Approach 1:
The patent segments the data flow handling into two parts: flow ID management (handled by UE for identification) and IP packet forwarding (handled by base stations). This segmentation allows base stations to forward only IP packets during SCG change without flow IDs, preventing connectivity switching errors, while the UE maintains flow identification through its own flow context and mapping tables.
Solution Approach 2:
The patent introduces the UE as an intermediary that handles flow ID mapping and management. The UE acts as a mediator between the flow identification function and the packet forwarding function. During SCG change, the UE uses its flow context and mapping tables to correctly identify and route packets, enabling accurate connectivity switching without requiring flow IDs in the forwarded packets between base stations.
3Device complexity
If flow IDs are included in forwarded packets during SCG change, then packet routing is simplified, but decoding errors occur at the receiving end
Solution Approach 1:
The patent extracts the flow ID from the packet forwarding path between base stations during SCG change. Flow ID management is separated from the IP packet forwarding function and handled by the UE through its flow context. This extraction simplifies the forwarding process at base stations (they only need to forward IP packets) while ensuring decoding accuracy at the receiving end by eliminating the source of confusion (flow ID inclusion) that would cause decoding errors.
Data Source
AI summary
A first base station (BS), comprising: at least one storage device, configured to store program codes; a first communication interfacing device, configured to transmit signals or to receive signals with at least one BS; a second communication interfacing device, configured to transmit signals or to receive signals with a plurality of communication devices; at least one processing circuit, configured to execute the program codes comprising following steps: (a) associating a first PDCP SDU to a first PDCP SN or associating an IP packet included in the first PDCP SDU, wherein the first PDCP SDU comprises a flow ID and an IP packet; (b) initiating a SCG change for a first communication device with a second BS; and (c) controlling the first communication interfacing device to forward the IP packet but not to forward the flow ID, to the second BS in response to the SCG change.