  In time-sensitive networks, bounds on worst-case delays are typically
obtained by using network calculus and assuming that flows are constrained by
bit-level arrival curves. However, in IEEE TSN or IETF DetNet, source flows are
constrained on the number of packets rather than bits. A common approach to
obtain a delay bound is to derive a bit-level arrival curve from a packet-level
arrival curve. However, such a method is not tight: we show that better bounds
can be obtained by directly exploiting the arrival curves expressed at the
packet level. Our analysis method also obtains better bounds when flows are
constrained with g-regulation, such as the recently proposed Length-Rate
Quotient rule. It can also be used to generalize some recently proposed
network-calculus delay-bounds for a service curve element with known
transmission rate.
