eMBMS File Repair Using Schedule Description Fragments
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Solution Overview
Problem
Current full file repair techniques in eMBMS systems are inadequate as they rely on the availability of the File Delivery Table (FDT) instance, which may not be received by user equipment (UE) when it is out of coverage or service, leading to incomplete file downloads and inability to initiate file repair.
Innovation Solution
The UE uses a schedule description fragment to determine if a file of interest has been missed by comparing file version information, triggering a full file repair at the end of a file or session broadcast, even without access to the FDT, by utilizing information elements like the end attribute of the file schedule element or the stop attribute of the session schedule element.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If current full file repair techniques are used, then file repair can be initiated when FDT is available, but file repair cannot be initiated when UE is out of coverage or service and FDT is not received
Solution Approach 1:
The UE performs preliminary actions by obtaining and storing schedule description fragments and file version information before the actual file delivery event. This allows the UE to have the necessary information ready to trigger file repair at the appropriate time even without real-time FDT access, resolving the contradiction between reliability and adaptability across different operational conditions
Solution Approach 2:
The patent introduces schedule description fragments as an intermediary mechanism that bridges the gap between FDT-based repair methods and out-of-coverage scenarios. These fragments contain essential scheduling and version information that enable file repair initiation without direct FDT access, allowing the system to adapt to various coverage conditions while maintaining reliable repair capability
2Manufacturing precision
If FDT-based file repair method is used, then file repair can be triggered based on FDT instance availability, but file download may be incomplete when FDT is not received
Solution Approach 1:
The UE obtains a copy of the schedule description fragment information through alternative means (e.g., previous reception, unicast transmission) instead of relying solely on the original FDT instance. This copied information contains sufficient details to trigger complete file repair, ensuring file download completeness even when the original FDT is unavailable
Solution Approach 2:
The patent changes the triggering parameter from FDT instance availability to schedule description fragment availability combined with file version information comparison. This parameter change allows the system to maintain precise file download completion detection without requiring the original FDT instance, preventing information loss
3Speed
If file repair is triggered immediately upon detecting file interest, then repair response time is reduced, but premature triggering may occur without proper timing information
Solution Approach 1:
The UE uses feedback from the schedule description fragment information (including end attributes and version information) to determine the appropriate timing for file repair initiation. This feedback mechanism ensures that repair is triggered at the correct time based on scheduled events rather than immediately, balancing rapid response with timing accuracy
Solution Approach 2:
The UE performs preliminary analysis of the schedule description fragment to identify the correct timing point for file repair initiation. By pre-processing this information and comparing file versions beforehand, the system can trigger repair at the optimal moment without premature or delayed activation, resolving the contradiction between speed and timing accuracy
Data Source
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AI summary
A method, an apparatus, and a computer program product for wireless communication are provided. The apparatus determines that a file of interest is transmitted within a service, determines a failure to download the file of interest, and triggers a repair procedure of the file of interest at a time corresponding to an end of a file delivery event, wherein the time is derived from one or more information elements included in broadcast schedule description.