Operation of the dynamic TDMA subnet relay system with HF bearers

Subnet relay (SNR) is a suite of protocols that was developed for the navies of Australia, Canada, New Zealand, the United Kingdom and the United States of America (AUSCANNZUKUS) to permit the deployment of masterless, ad-hoc, self-configuring tactical IP networks with inherent relay capabilities. Line-of-Sight (LOS) radio assets, primarily in the VHF and UHF bands, are used to give tactical commanders an intra-task-group data networking system under their local control, without having to rely on strategic reach-back through satellite. SNR is described in ACP 200 and is currently under consideration for adoption as a NATO STANAG. In this paper we consider the use of SNR with HF bearers which provide much greater ranges than the VHF and UHF bearers normally associated with SNR, but at substantially reduced data rates.