Delay Bounds Calculus for Variable Length Packet Transmissions under Flow Transformations

A fundamental contribution of network calculus is the convolution-form representation of networks which enables tight end-to-end delay bounds. Recently, this has been extended to the case where the data flow is subject to transformations on its way to the destination. Yet, the extension, based on so-called scaling elements, only applies to a setting of identically sized data units, e.g., bits. In practice, of course, one often has to deal with variable-length packets. Therefore, in this paper, we address this case and propose two novel methods to derive delay bounds for variable-length packets subject to flow transformations. One is a relatively direct extension of existing work and the other one represents a more detailed treatment of packetization effects. In a numerical evaluation, we show the clear superiority of the latter one and also validate the bounds by simulation results.