L1 Pre-signalling for Extension Frame Detection in DVB Broadcast
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Solution Overview
Problem
In digital broadband broadcast networks, such as DVB-H and DVB-T2 systems, the existing PSI/SI signalling is inefficient due to long repetition periods and high bandwidth requirements, leading to sub-optimal user experience and increased costs, and there is a lack of effective methods to signal the presence of Future Extension Frames (FEFs) which are not part of the current system, causing receivers to treat them as 'black holes' without knowing their timing.
Innovation Solution
A signalling scheme that informs receivers about the presence, timing, and duration of Future Extension Frames (FEFs) within the broadcast system, allowing them to be ignored when not decodable, by using specific parameters in the L1 pre-signalling and L2 signalling data, such as FEF_IN_USE, FEF_TYPE, FEF_LENGTH, FEF_START_FRAME_IDX, and FEF_INTERVAL, which are transmitted alongside regular data frames.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If PSI/SI signalling is used in DVB-H systems, then program and service information can be transmitted, but the repetition period is long and bandwidth consumption is high
Solution Approach 1:
The patent extracts the essential function of signalling (informing receivers about frame structure and service information) and separates it from the traditional PSI/SI table mechanism. By using L1-pre symbols with fixed, compact formatting, the system conveys the same critical information with minimal bandwidth, eliminating the need for lengthy PSI/SI tables while maintaining complete receiver functionality.
Solution Approach 2:
The patent replaces the expensive, bandwidth-intensive PSI/SI signalling mechanism with a lightweight L1-pre symbol system. These symbols are transmitted once at the beginning of each frame, consuming minimal bandwidth while providing all necessary information for frame processing and service identification throughout the entire frame duration.
2Loss of information
If PSI/SI tables are used for signalling, then service information is provided, but the repetition period is long leading to sub-optimal user experience
Solution Approach 1:
The patent performs preliminary action by embedding all necessary service information and frame structure details directly into the L1-pre symbols at the beginning of each frame. This eliminates the need for receivers to wait for subsequent PSI/SI table updates, as all critical information is immediately available for processing and display.
Solution Approach 2:
The L1-pre symbols are transmitted continuously at the start of every frame, providing uninterrupted service information flow. This continuous availability of frame structure and service data eliminates the gaps and delays inherent in periodic PSI/SI table repetitions, ensuring optimal user experience throughout the broadcast.
3Adaptability or versatility
If Future Extension Frames are inserted in the broadcast system, then system flexibility is improved, but receivers cannot identify when they occur treating them as black holes
Solution Approach 1:
The patent introduces L1-pre symbols as an intermediary signalling layer between the broadcast transmitter and receivers. These symbols act as a mediator that carries explicit information about FEF presence, timing, and duration, enabling receivers to accurately detect and synchronize with extension frames without requiring changes to the core broadcast protocol.
Solution Approach 2:
The L1-pre symbols perform preliminary action by announcing FEF parameters before the actual extension frames are transmitted. This advance notification allows receivers to prepare their timing mechanisms and synchronization logic in advance, ensuring accurate detection and processing of FEFs when they occur.
4Adaptability or versatility
If L1 signalling size varies with the amount of PLPs, then system adaptability is improved, but L1-pre signalling becomes more complex
Solution Approach 1:
The patent segments the L1 signalling into two distinct parts: fixed L1-pre symbols containing essential frame information, and variable L1 signalling carrying PLP-specific data. This segmentation allows the variable portion to adapt to different PLP configurations while keeping the pre-signalling portion simple, fixed, and easily processed by receivers regardless of system complexity.
Data Source
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AI summary
Aspects of the invention are directed to signalling extension frames in a telecommunication system. Extension-frame-signalling data may signal whether one or more extension parts are present in one or more gaps in time between data frames, when the one or more extension parts occur, and one or more durations for the one or more extension parts. The one or more extension parts may occur on the same radio frequencies as the data frames. The extension- frame-signalling data may signal when the one or more extension parts occur by signalling after which of one or more data frames in a super frame the extension parts occur. The one or more durations for the extension parts may be expressed in units of time.