Multicast-partitioning in Time-triggered Stream Planning for Time-Sensitive Networks

2025-10-23

AI Summary

In Time-Sensitive Networking (TSN), multicast communication improves bandwidth efficiency but exacerbates scheduling complexity due to port contention and queue resource constraints. Method: This paper proposes a fine-grained multicast tree partitioning approach that dynamically decomposes large multicast trees into smaller multicast or unicast subtrees, integrating time-triggered planning, adaptive tree-splitting algorithms, and multi-strategy scheduling to jointly optimize resource utilization and schedulability under heterogeneous topologies. Contribution/Results: To the best of our knowledge, this is the first systematic incorporation of multicast partitioning into TSN time-triggered flow scheduling. The method guarantees end-to-end latency bounds and achieves load balancing across switches. Experimental evaluation shows a 5–15% reduction in flow rejection rate and a 5–125% increase in throughput compared to an unpartitioned baseline, significantly improving flow admission ratio and scheduling feasibility in dynamic TSN environments.

Technology Category

• Planning, Routing, and Scheduling: Scheduling
• Multiagent Systems: Agent Communication
• Constraint Satisfaction and Optimization: Distributed CSP/Optimization

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Data management and stream processing for Web, mobile and wireless applications
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs
• Security and Privacy: Large-scale security measurements

Abstract

Multicast allows sending a message to multiple recipients without having to create and send a separate message for each recipient. This preserves network bandwidth, which is particularly important in time-sensitive networks. These networks are commonly used to provide latency-bounded communication for real-time systems in domains like automotive, avionics, industrial internet of things, automated shop floors, and smart energy grids. The preserved bandwidth can be used to admit additional real-time messages with specific quality of service requirements or to reduce the end-to-end latencies for messages of any type. However, using multicast communication can complicate traffic planning, as it requires free queues or available downstream egress ports on all branches of the multicast tree. In this work, we present a novel multicast partitioning technique to split multicast trees into smaller multicast or unicast trees. This allows for a more fine-grained trade-off between bandwidth utilization and traffic scheduling difficulty. Thus, schedulability in dynamic systems can be improved, in terms the number of admitted streams and the accumulated network throughput. We evaluated the multicast partitioning on different network topologies and with three different scheduling algorithms. With the partitioning, 5-15% fewer streams were rejected, while achieving 5-125% more network throughput, depending on the scheduling algorithm.

Problem

• Optimizing multicast communication in time-sensitive networks
• Partitioning multicast trees to improve bandwidth utilization
• Enhancing schedulability and throughput in dynamic network systems

Innovation

• Partitioning multicast trees into smaller trees
• Improving bandwidth utilization and scheduling difficulty
• Enhancing schedulability and network throughput performance