Short paper

TLDR

Reactive jamming targets only packets already on the air, minimizing detection risk, and is considered a key step toward optimal jamming strategies. The study investigates the feasibility of software‑defined reactive radio‑frequency jamming against IEEE 802.15.4 networks. The authors identify physical‑layer loss causes in 802.15.4 and use these insights to build a USRP2‑based prototype that classifies transmissions in real time and selectively jams them. The prototype demonstrates microsecond reaction times, symbol‑level precision, and achieves 97.6 % jamming rate with one jammer and over 99.9 % with two, proving software‑defined reactive jamming is practical.

Abstract

In this work, we take on the role of a wireless adversary and investigate one of its most powerful tools---radio frequency jamming. Although different jammer designs are discussed in the literature, reactive jamming, i.e., targeting only packets that are already on the air, is generally recognized as a stepping stone in implementing optimal jamming strategies. The reason is that, while destroying only selected packets, the adversary minimizes its risk of being detected. One might hope for reactive jamming to be too challenging or uneconomical for an attacker to conceive and implement due to its strict real-time requirements. Yet, in this work we disillusion from such hopes as we demonstrate that flexible and reliable software-defined reactive jamming is feasible by designing and implementing a reactive jammer against IEEE 802.15.4 networks. First, we identify the causes of loss at the physical layer of 802.15.4 and show how to achieve the best performance for reactive jamming. Then, we apply these insights to our USRP2-based reactive jamming prototype, enabling a classification of transmissions in real-time, and reliable and selective jamming. The prototype achieves a reaction time in the order of microseconds, a high precision (such as targeting individual symbols), and a 97.6% jamming rate in realistic indoor scenarios for a single reactive jammer, and over 99.9% for two concurrent jammers.