Deep Learning Hierarchical Representation From Heterogeneous Flow-Level Communication Data

The success of a detection model depends heavily on feature engineering. Deep learning has been successfully applied in numerous research fields as a universal representation learning method. However, the heterogeneity of flow-level communication data obstructs the application of deep learning to communication representation learning, and research on this problem is still lacking. To cope with this problem, we propose a heterogeneous communication data-encoding approach to extract fixed-size encoding data to apply deep learning to heterogeneous communication data by preserving the spatiotemporal characteristics of the data. Then, we propose a feature extractor based on deep learning to automatically learn hierarchical and robust communication representations without expert knowledge. We show that the proposed approach can replicate and optimize the key steps of feature engineering well and learn hierarchical representations directly from heterogeneous communication data. Moreover, compared with features extracted with principal component analysis (PCA), manifold learning and manually crafted methods, the features extracted by deep learning are more robust and are characterized by their better adaptability to various classifiers and datasets. To the best of our knowledge, the initial work here is the first to apply deep learning techniques to heterogeneous flow-level data; consequently, the heterogeneous communication data processing method can provide technical means for the application of deep learning in other communication-related research fields.