ECE 1545 Service Curve Earliest Deadline Due (SCED) or How to construct a scheduler from a service curve

How does SCED work? Goal: Realize a minimum service curve , ie., For an arrival at , compute Set deadline of arrival to Transmit all backlogged traffic in the order of deadlines If , service curve condition is satisfied Traffic Time

Conceptual issue Computation of amounts to computing a pseudo-inverse: SCED becomes more intuitive if expressed using max-plus algebra Max-plus and min-plus formulations of SCED are equivalent, … … as long as we use use real-valued notions of time and traffic  Fluid-flow SCED

Summary of duality of min-plus and max-plus network calculus [Liebeherr `17]

Now back to SCED …. (max-plus version)

Max-plus SCED Goal: Realize a max-plus service curve , ie., For bit value , compute deadline: Transmit all backlogged traffic in the order of deadlines Then: Time Traffic