Transmission Early-Stopping Scheme for Anti-Jamming Over Delay-Sensitive IoT Applications

Time-critical, wireless Internet of Things applications have been drawing increasing attention lately. The most characterizing feature of such applications is that a packet has to be delivered within a certain deadline. Not meeting the deadline could result in severe consequences. Jamming attacks utilize the shared nature of the wireless medium to corrupt transmitted packets. Although a corrupted packet could be retransmitted several times until successful delivery, this would add latency and hence could lead to missing the deadline. In this paper, we propose a jamming detection scheme that uses the packet transmission time as a statistic to make detection decisions. The key insight behind our proposed scheme is that, a long transmission/retransmission time for a certain packet indicates an abnormal condition, such as jamming. Therefore, we devise an optimal transmission-time threshold that, when exceeded, a jammer is detected. Unlike most existing detection schemes where, in case of a detection error, retransmission could continue until the deadline is reached, our scheme aims to detect the jammer earlier than the deadline so that the remaining time (until the deadline) could be utilized in retransmitting the packet over a safe channel. The proposed detection scheme is a general framework that can be applied to many situations. After conducting a thorough analysis, we apply the proposed early-stop jamming detection framework to the distributed coordinated function medium access mechanism specified by the 802.11 standard. Our simulation results show significant performance gains achieved by the proposed scheme.