Understanding and representing traffic patterns are key to detecting anomalous trajectories in the transportation domain. However, some trajectories can exhibit heterogeneous maneuvering characteristics despite confining to normal patterns. Thus, we propose a novel graph-based trajectory representation and association scheme for extraction and confederation of traffic movement patterns, such that data patterns and uncertainty can be learned by deep learning (DL) models. This paper proposes the usage of a recurrent neural network (RNN)-based evidential regression model, which can predict trajectory at future timesteps as well as estimate the data and model uncertainties associated, to detect anomalous maritime trajectories, such as unusual vessel maneuvering, using automatic identification system (AIS) data. Furthermore, we utilize evidential deep learning classifiers to detect unusual turns of vessels and the loss of transmitted signal using predicted class probabilities with associated uncertainties. Our experimental results suggest that the graphical representation of traffic patterns improves the ability of the DL models, such as evidential and Monte Carlo dropout, to learn the temporal-spatial correlation of data and associated uncertainties. Using different datasets and experiments, we demonstrate that the estimated prediction uncertainty yields fundamental information for the detection of traffic anomalies in the maritime and, possibly in other domains.

The automatic identification system (AIS) has become an essential tool for maritime security. Nevertheless, how to effectively use the static and dynamic voyage information of the AIS data in maritime traffic situation awareness is still a challenge. This paper presents a comparative study of artificial intelligence (AI) techniques on their effectiveness in dealing with various anomalies in maritime domain using the AIS data. The AIS on-off switching (OOS) anomaly is critical in maritime security, since AIS technology is susceptible to manipulation and it can be switched on and off to hide illegal activities. Thus, we try to detect and distinguish between intentional and non-intentional AIS OOS anomalies through our AI -assisted anomaly detection framework. We use AIS data, in particular positional and navigational status of vessels, to study the effectiveness of seven AI techniques, such as artificial neural network, support vector machine, logistic regression, k-nearest neighbors, decision tree, random forest and naive Bayes, in detecting the AIS OOS anomalies. Our experimental results show that ANN and SVM are the most suitable techniques in detecting the AIS OOS anomalies with 99.9% accuracy. Interestingly, the ANN model outperforms others when trained with a balanced (i.e., same order of samples per class) dataset, and SVM, on the other hand, is suitable when training dataset is unbalanced.

Optical networks are prone to power jamming attacks intending service disruption. This paper presents a Machine Learning (ML) framework for detection and prevention of jamming attacks in optical networks. We evaluate various ML classifiers for detecting out-of-band jamming attacks with varying intensities. Numerical results show that artificial neural network is the fastest (106 detection per second) for inference and most accurate (≈ 100%) in detecting power jamming attacks as well as identifying the optical channels attacked. We also discuss and study a novel prevention mechanism when the system is under active jamming attacks. For this scenario, we propose a novel resource reallocation scheme that utilizes the statistical information of attack detection accuracy to lower the probability of successful jamming of lightpaths while minimizing lightpaths' reallocations. Simulation results show that the likelihood of jamming a lightpath reduces with increasing detection accuracy, and localization reduces the number of reallocations required.

Spectrum defragmentation (DF) as a connection reconfiguration method is essential in elastic optical networks (EONs) in order to minimize connection blocking probability. This paper proposes the first exact Markov model to computing exact blocking probabilities in EONs with DF by taking into account the occupancy status of spectrum slices of all network links, and waiting and serving connections during a DF process. Since the complexity of the exact Markov model increases exponentially with the network capacity and size, we propose a reduced state model where a link occupancy state is defined by the total occupied slices on a fiber link. Furthermore, using a spectrum fragmentation factor in each occupancy state we calculate state-and class-dependent connection setup rates, which is used to compute approximate blocking in EONs with DF. Notably, we show individually the distinct blocking values, one due to resource unavailability and the other due to fragmentation, both under a random-fit and a first-fit spectrum allocation policies. Our numerical results show that the DF process is very useful in reducing overall connection blocking in EONs. We also observe that blocking due to spectrum fragmentation can be reduced, but not eliminated in a mesh network topology even when an optimal DF scheme is deployed.

Scrambling or information randomization has been effectively used in various applications to prevent the information falling into the hands of rogue attackers. In this paper, we use the idea of spectrum scrambling to proactively randomize the spectrum across multiple fiber cores to improve connections' security, while at the same time effectively defragmenting the spectrum to improve connections' blocking performance. To this end, we propose a scheme called random spectrum defragmentation (RSD), and model the occupancy pattern of a multi-core fiber link using a multi-class continuous-time Markov chain (CTMC) under the two different spectrum allocation methods, first-fit and random-fit. As the efforts have been on preventing unauthorized access to optical channels, we show that scrambling can be effectively used to help dealing with the physical layer attacks. At the same time, numerical results show that also the blocking can be improved for a particular so-called randomization process (RP) arrival rate, and lower connection reconfiguration time.

Data randomization or scrambling has been effectively used in various applications to improve the data security. In this paper, we use the idea of data randomization to proactively randomize the spectrum (re)allocation to improve connections' security. As it is well-known that random (re)allocation fragments the spectrum and thus increases blocking in elastic optical networks, we analyze the tradeoff between system performance and security. To this end, in addition to spectrum randomization, we utilize an on-demand defragmentation scheme every time a request is blocked due to the spectrum fragmentation. We model the occupancy pattern of an elastic optical link (EOL) using a multi-class continuous-time Markov chain (CTMC) under the random-fit spectrum allocation method. Numerical results show that although both the blocking and security can be improved for a particular so-called randomization process (RP) arrival rate, while with the increase in RP arrival rate the connections' security improves at the cost of the increase in overall blocking.