Broadcasting Control Time Correction for Leap Second Adjustments
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Solution Overview
Problem
Existing methods for handling leap second adjustments in broadcast signal processing, such as those described in PTL 4, cause significant distortion in time progression and can lead to missed triggers due to abrupt time corrections, particularly during leap second insertion and deletion.
Innovation Solution
A broadcasting control apparatus and method that adjusts system time by gradually changing the time progression rate over a predetermined period before a leap second adjustment, ensuring minimal deviation from the actual elapsed time, using equations to calculate corrected system time based on the reference time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If leap second adjustment is performed by displaying time again or skipping time, then time synchronization with reference time is achieved, but time sequence order is broken and triggers may be missed
Solution Approach 1:
The patent applies dynamics by making the time progression rate adjustable rather than fixed. The system dynamically changes the time progression rate from 1.0 to (D-1)/D or (D+1)/D during the correction period to accommodate leap second adjustments while maintaining continuous time progression. This allows the system to adapt its time advancement speed to match the reference time changes without breaking the time sequence.
Solution Approach 2:
The patent changes the parameter of time progression rate from a constant value to a variable value that can be adjusted based on leap second adjustment needs. By modifying this parameter dynamically during the correction period, the system achieves time synchronization while preventing time duplication or skipping, thereby maintaining trigger reliability.
2Loss of time
If time correction is performed abruptly at leap second moment, then time synchronization is achieved quickly, but significant distortion in time progression occurs
Solution Approach 1:
The patent implements preliminary action by starting the time correction process D seconds before the leap second adjustment moment. During this correction period, the time progression rate is gradually adjusted rather than changing abruptly at the leap second moment. This preliminary gradual adjustment prevents significant distortion in time progression while still achieving synchronization in a timely manner.
Solution Approach 2:
The patent uses periodic action by dividing the time correction into a structured period of D seconds leading up to the leap second moment. Within this period, the time progression rate is systematically adjusted in a controlled manner, providing stable and predictable time progression rather than abrupt changes.
3Measurement precision
If time progression rate is increased to compensate for leap second deletion, then time synchronization is maintained, but time display may skip seconds
Solution Approach 1:
The patent applies dynamics by adjusting the time progression rate dynamically during the correction period before leap second deletion. Instead of skipping seconds abruptly, the system gradually increases the time progression rate from 1.0 to (D+1)/D, ensuring continuous time display that maintains synchronization accuracy without disrupting operational continuity.
Data Source
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AI summary
In order to enable more stably processing of a broadcast signal in a case in which leap second adjustment is performed, a broadcasting control apparatus is provided which includes a time generating unit configured to generate a system time for broadcasting control, the system time being synchronized with a reference time in accordance with a predetermined time protocol, and a correction unit configured to, when leap second adjustment information indicating that leap second adjustment is scheduled to be completed at a first time in the reference time is received, correct the system time by a correction amount depending on a time length D over a correction period having the time length D from a second time earlier than the first time, wherein the time length D is set such that a correction amount per second of the system time is equal to or less than a cycle corresponding to an inverse of a video frame rate.