Session Date/Time: 05 Nov 2024 16:30

tvr

Summary

The TVR working group meeting focused on the applicability, requirements, and data models for Time-Variant Networks. Key discussions centered on the scope of the applicability document, security considerations for the requirements document, the ALTO off-path solution, and updates to the YANG data model. The challenges of time synchronization in deep space environments were also discussed.

Key Discussion Points

Applicability Document Scope: The group discussed whether the applicability document should focus solely on Tidal Networks or include multiple use cases. There was a general agreement that including multiple use cases would be beneficial for showcasing the applicability of TVR in different scenarios. The question of potentially having multiple applicability documents (one per major use case) was raised.
TVR Requirements Document: Security considerations were a major focus, with a discussion on whether these should be framed as considerations or requirements. There was also a suggestion to include an introduction section. Motion as a constraint factor, particularly for space-based applications, was proposed.
ALTO Off-Path Solution: The presentation on the ALTO off-path mechanism for exposing scheduled changes sparked discussions about its advantages, particularly in terms of offloading processing and enabling external consumption of topological changes and associated metrics.
Schedule YANG Model: Updates to the YANG data model included changes to device identifiers to use URIs and editorial clarifications. Discussions covered the units of measure for delay attributes (microseconds), and the representation of time (UTC vs. local spacecraft time).
Deep Space Time Synchronization: Marc Blanchet presented challenges encountered implementing the YANG models with earth-to-mars schedules, including how to relate local spacecraft time (SCET) to UTC given variable one-way light time.

Decisions and Action Items

Applicability Document Scope: Discuss the scope of the applicability document on the mailing list. The specific question of the benefits of one vs. many applicability documents for the different use cases will be addressed there.
TVR Requirements Document: Clarify whether security considerations are requirements and potentially separate them into distinct sections. Review and update with motion as a constraint factor. Add an introduction section to the document.
ALTO Off-Path Solution: Encourage working group members to review the latest version of the ALTO draft and provide comments on the mailing list.
Schedule YANG Model: Request YANG doctor review for the modules. Ensure the requirements document is in last call before the YANG data model last call. Investigate the possibility of time zone augmentations.
Deep Space Time Synchronization: Contact CCSDS for information on time synchronization over astronomical distances.

Next Steps

Mailing list discussions on applicability document scope, ALTO draft, Mars time zone, and schedule YANG model.
Updates to the requirements document based on meeting discussions.
Implementation and demo of the ALTO off-path solution.
YANG doctor review of the schedule, node, and topology YANG modules.