Mix-Flow Scheduling for Concurrent Multipath Transmission in Time-Sensitive Networking

Time-Sensitive Networking (TSN) that promises bounded delay and jitter by realizing zero congestion has been looked upon as a promising technology for delay-critical applications. Most of the prior works on TSN implicitly adopt the single path transmission. The conventional algorithms for the calculation of gate control list waste bandwidth to satisfy the constraints of time slots. In this paper, we design an SDN-based architecture, which incorporates the Concurrent Multipath Transmission (CMT) mechanism. CMT transmits the packets through multiple paths so that it can improve link utilization by realizing load balancing, and increase the number of dispatchable flows. We propose an extensible heuristic algorithm, which is Multipath Mix-Flow Scheduling (MPMFS), for flows with various QoS requirements. MPMFS dynamically schedules the flow splitting, routing, and time slot configuration of CMT. MPMFS also solves the disorder problem caused by CMT. Using the single path scheduling as the baseline, we show that the proposed architecture has a better performance on delay, jitter, resource utilization, and dispatchable flows. The simulation results also show that the algorithm execution time is linearly related to the size of delay-critical traffic.