An Experimental Study of Effective Jamming in Underwater Acoustic Links

As Underwater Acoustic Networks (UANs) become more commonly utilized, it is crucial to research security against interference and jamming as the networks are based in an exposed environment. We have identified some of the key communication vulnerabilities across underwater networks using basic jamming techniques. Three commercial modems from the United States were analyzed in our tests, particularly LinkQuest, AquaSeNT and Benthos modems, which use DSSS, OFDM and MFSK transmission schemes. We observed that each modem has a preamble that contains a packet that is vulnerable to a shorter, more efficient targeted jam. Each modem is also vulnerable to single tone jamming at certain frequencies in the bandwidth, and can be reliably but less efficiently jammed with frequency sweeps.