Anti-jam communications and covertness in radio networks - Final report

Authors:

  • Jimmi Grönkvist
  • Arwid Komulainen
  • Anders Hansson
  • Ulrika Uppman

Publish date: 2021-01-19

Report number: FOI-R--5078--SE

Pages: 24

Written in: Swedish

Keywords:

  • radio networks
  • SCB
  • anti-jam
  • covertness
  • LPI

Abstract

The development of modern tactical waveforms has largely focused on capacity and only to a small degree on anti-jamming capabilities. Another threat not usually adressed during the design of tactical waveforms is enemy signal intelligence, i.e. the risk that an enemey can detect and localize units and networks. This final report summarizes the work done in the project Störskydd och smygförmåga i radionät (Anti-jamming and covertness in radio networks). The focus of the project has been on estimating the sensitivity to jamming of modern tactical radio networks and characterizing the probability of them being detected by an enemy. The work has mainly focused on narrowband waveforms based on synchronized cooperative broadcast (SCB) that use frequency hopping to combat jamming. The anti-jamming performance of waveforms based on SCB generally outperforms that of traditionally used waveforms. The primary threat is a follower jammer and the project has modelled and examined performance of narrowband waveforms in the presence of jamming. A feasibility study of whether it is possible to increase the frequency hopping rate for narrowband waveforms have been performed. The results indicate that it is possible to increase the hopping rate while maintaining a given data rate. The cost of doing so is either increased bandwidth usage or decreased communication range. Covertness is rarely a design criterion for tactical radio networks. Work performed shows that typical radio networks can be detected over large distances. It is further shown that it is possible to lower the output power, and thereby the detection distances, given that the waveform is based on SCB. The alternative of using covert waveforms is putting the network into radio silence. A study has been performed analyzing the possibilities of radio silence in radio networks. The conclusion is that it is possible, in particular when the waveforms used are based on SCB. The overall results from the project show that waveforms based on SCB can increase the capacity of narrowband waveforms, improve the anti-jamming capabilities and make it possible to increase the covertness of radio networks.