Adaptive Scheduling over a Wireless Channel under Constrained Jamming

Abstract

We consider a wireless channel between a single pair of stations (sender and receiver) that is being “watched” and disrupted by a malicious, adversarial jammer. The sender’s objective is to transmit as much useful data as possible, over the channel, despite the jams that are caused by the adversary. The data is transmitted as the payload of packets, and becomes useless if the packet is jammed. In this work, we develop deterministic scheduling algorithms that decide the lengths of the packets to be sent, in order to maximize the total payload successfully transmitted over period T in the presence of up to f packet jams, useful payload. We first consider the case where all packets must be of the same length and compute the optimal packet length that leads to the best possible useful payload. Then, we consider adaptive algorithms; ones that change the packet length based on the feedback on jammed packets received. We propose an optimal scheduling algorithm that is essentially a recursive algorithm that calculates the length of the next packet to transmit based on the packet errors that have occurred up to that point. We make a thorough non trivial analysis for the algorithm and discuss how our solutions could be used to solve a more general problem than the one we consider.