Time Tag Processing Unit for Packet Delay Variation Mitigation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for transporting time-related information in packet switched networks face challenges such as layer violations and security concerns, particularly when using Precision Time Protocol (PTP), which can affect accuracy and introduce complexity in managing packet delay variations.
Innovation Solution
A time-aware device with a time tag processing unit that processes time tag data within a header of a packet switched network, mitigating packet delay variations and avoiding layer violations by incorporating a time tag data field that includes a source timestamp, device timestamp, and correction field, allowing for accurate time alignment without decrypting payload data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If Transparent Clock is used to modify correction field of packets, then packet delay variation effects are mitigated and sub-nanosecond accuracy is achieved, but layer violations occur and system security is undermined
Solution Approach 1:
The invention segments the time adjustment function by introducing a separate Time Adjustment Packet (TAP) mechanism that operates independently from the data payload. The TAP contains time adjustment information that is processed separately from the original data packet, avoiding modification of the payload while still achieving time synchronization. This segmentation resolves the contradiction by maintaining protocol compliance (not modifying data fields) while achieving accurate time alignment through the dedicated TAP mechanism.
Solution Approach 2:
The invention introduces a Time Adjustment Packet (TAP) as an intermediary mechanism between the time source and the data packets. Instead of directly modifying the correction field of data packets (which causes layer violations), the TAP serves as an intermediary that carries time adjustment information separately. This intermediary approach allows time synchronization to be achieved without violating protocol layers or compromising the integrity of the original data packets, thus resolving both accuracy and reliability concerns.
2Measurement precision
If time protocol packets are modified in payload fields, then time alignment accuracy is improved, but processing complexity and delay increase
Solution Approach 1:
The invention segments the time adjustment function by separating time adjustment information from the data payload into a dedicated Time Adjustment Packet (TAP). This segmentation allows the time adjustment mechanism to operate independently from the data processing path, reducing the complexity of modifying payload fields while maintaining accurate time alignment. The TAP is processed separately, avoiding the need to deep-inspect or modify the original data packet structure.
3Measurement precision
If payload fields are modified for time adjustment, then time alignment is improved, but security is compromised due to need to unlock encrypted payloads
Solution Approach 1:
The invention segments time adjustment operations from data payload processing by using a separate Time Adjustment Packet (TAP) mechanism. This segmentation ensures that time adjustment information is processed independently from the encrypted data payload, eliminating the need to decrypt or modify the payload for time synchronization purposes. The TAP mechanism operates at the network layer without touching the application layer payload, thus maintaining security while achieving accurate time alignment.
Solution Approach 2:
The Time Adjustment Packet (TAP) acts as an intermediary that carries time adjustment information separately from the encrypted data payload. This intermediary mechanism allows time synchronization to be achieved without accessing or modifying the encrypted payload, thereby maintaining security. The TAP processes time adjustment information at the network layer, keeping the encrypted payload intact and inaccessible to the time adjustment mechanism.
Data Source
Figure 1~2A
Figure 2B~2C
Figure 3
AI summary
A time aware device for a packet switched network (1) comprising at least one time tag processing unit (2A;3A;4A) adapted to process time tag data of a predetermined time tag data field (TTDF) provided within a header of a tagged data packet (TDP) transported in said packet switched network (1) to provide time related information reflecting a delay undergone by said tagged data packet (TDP) during its transport in said packet switched network (1).