text: We unveil the existence of a vulnerability in Wi-Fi, which allows an adversary to remotely launch a Denial-of-Service (DoS) attack that propagates both in time and space. This vulnerability stems from a coupling effect induced by hidden nodes. Cascading DoS attacks can congest an entire network and do not require the adversary to violate any protocol. We demonstrate the feasibility of such attacks through experiments with real Wi-Fi cards, extensive ns-3 simulations, and theoretical analysis. The simulations show that the attack is effective both in networks operating under fixed and varying bit rates, as well as ad hoc and infrastructure modes. To gain insight into the root-causes of the attack, we model the network as a dynamical system and analyze its limiting behavior. The model predicts that a phase transition (and hence a cascading attack) is possible when the retry limit parameter of Wi-Fi is greater or equal to 7, and characterizes the phase transition region in terms of the system parameters.
  @cite_41: The objective of the paper is to provide qualitative insight into the global effects of distributed mechanisms, such as carrier sense multiple access (CSMA) and rate control, on the performance and stability of multi-hop wireless networks. Toward this end, we introduce a linear queueing network model where the service capacity of each node is modulated by the transmission state of its neighbor. We derive lower bounds on the steady-state utilization at each queue of such networks and demonstrate the existence of a phase transition phenomenon, whereby infinitesimal traffic increase at a single node in the network can suddenly render the entire network instable. We also present NS simulation results that show how this phenomenon can actually take place in IEEE 802.11 multi-hop wireless networks. Our results have direct bearing on rate control schemes, in that they indicate a minimum admissible threshold rate required to prevent network instability.
  @cite_19: Hidden nodes are a fundamental problem that can potentially affect any wireless network where nodes cannot hear each other. Although the hidden node problem is well known, so far only few papers have quantified its effects in a comprehensive manner. This paper represents a first step towards getting a quantitative insight into the impact of hidden nodes on the performance of wireless networks. We first carry out an exact queuing-theoretic analysis for a 4-node segment and derive analytical expressions for the probability of packet collision, the mean packet delay, and the maximum throughput, based on a model that closely follows the IEEE 802.11 standard. We then extend the analysis and provide an approximation for a general linear topology that is asymptotically exact at low load. Finally, we perform detailed simulations to validate our analytical results and show their applicability to predict the performance of IEEE 802.11 networks with hidden nodes. The simulation and analysis closely match. Moreover, they reveal that the impact of hidden nodes propagates through the network causing some nodes to saturate at load as low as 15 of the capacity.
summary: The work in @cite_19 @cite_41 show that local coupling due to interferences can have global effects on wireless networks. Thus, @cite_19 proposes a queuing-theoretic analysis and approximation to predict the probability of a packet collision in a multi-hop network with hidden nodes. It shows that the sequence of the packet collision probabilities in a linear network converges to a fixed point. The work in @cite_41 evaluates the impact of rate adaption and finds out that traffic increase at a single node can congest an entire network, and points out the existence of a phase transition.