WHAC-A-MOLE

Obfuscation techniques may be used to increase the difficulty of localizing and identifying RF emissions, creating a logical fog over the electromagnetic spectrum (EMS) environment, reducing the situational awareness (SA) of an adversary. WHAC-A-MOLE (Wireless Heterogeneous Adaptive Communications Architecture for Multi-Waveform Obfuscation of Localizable Emissions)-is presented as an overlay protocol for a network of multiple-transceiver software-defined radio (SDR) platforms. The system obfuscates communications networks by creating a time-based emissions scheme of heterogeneous waveforms that can be dynamically allocated to different frequency channels and use different physical characteristics (modulation, power, coding, spreading, etc.) for each predetermined time period. The basic concept employs a shared schedule for waveform execution and time division multiple access (TDMA). Based on the number of transceivers, additional layers of complexity can be added that can be tailored based on the emission threat profile. The technique explored in this work uses agile, pseudo-random waveform selection to augment traditional frequency hopping as a means to increase the difficulty of adversary targeting and signal characterization. The WHAC-A-MOLE system was designed and implemented in development radio hardware and demonstrated a basic capability for establishing a time-division based overlay scheme beyond traditional frequency hopping. This work established a baseline proof of concept, using a simplified network structure, to demonstrate basic automation of waveform switching in the laboratory environment, followed by initial steps in implementing a fully automated process.