Tutorials

This tutorial covers the concepts in network security protocols, including basic cryptography, authentication protocols, and an overview of current security protocol standards. It approaches the problems first from a generic conceptual viewpoint, covering the problems and the types of technical approaches for solutions. For example, how would encrypted email work with distribution lists? What are the performance and security differences in basing authentication on public key technology versus secret key technology? What is the functional difference between protecting communication using IPsec vs SSL? How can we design a PKI that will avoid creating monopolies, and that will be manageable and scalable? What kinds of mistakes do people generally make when designing protocols? Armed with a conceptual knowledge of the toolkit of tricks that allow authentication, encryption, key distribution, etc., we describe the current standards, including Kerberos, S/MIME, SSL, IPsec, PKI, and web security.

Network monitoring for anomaly detection, wireless network geo-localization, and disease tracking in social networks are enabled by statistical signal processing. This tutorial will cover statistical machine learning approaches to tracking and localization in such network applications. We will develop several methods of inference for cooperative sensor localization, target tracking, classification, and anomaly detection. In particular, we will show how approaches from Bayesian networks, maximum likelihood, manifold learning, and projection onto convex sets (POCS) can be applied. Emphasis will be on scalable distributed implementation. These approaches will be illustrated for problems in environmental monitoring, wireless network surveillance, Internet security, and public health.

This tutorial presents a friendly introduction to the applied fixed point theory of quasi-nonexpansive mapping both in terms of the theoretical background and a variety of signal processing applications. The theory offers unified view and powerful algorithms, e.g., the hybrid steepest descent method and adaptive projected subgradient method to broad range of modern signal processing applications including constrained inverse problems, nonstationary adaptive filtering problems, and online machine learning problems.

Lossy networks, such as the Internet, peer-to-peer, ad hoc, wireless and sensor networks, have to combat the problems of packet loss and delay. Retransmission is often undesirable or impossible due to latency constraints or faulty devices, or for the sake of bandwidth economy and power conservation. An alternative is to transmit on a best-effort basis. This has shifted the burden of reliability from the network protocols toward the design of network-aware codes, and led to a proliferation of research literature on multiple description coding (MDC) for packet-switched networks and erasure channels. In this tutorial, we first cover the theoretical fundamentals of multiple description coding, the common MDC design techniques, and some examples of MDC applications in multimedia communications. Then we look into the network routing aspect of MDC code streams, which is a new line of enquiry. We will discuss some recent techniques for iterative optimization of MDC code design and the network flows of MDC code streams. We will also relate MDC to joint source-channel coding, and present algorithms for joint source-channel MAP decoding of MD-coded signals.

The Ultra Mobile Broadband (UMB) system is designed for robust mobile broadband access and is optimized for high spectral efficiency and short latencies using advanced modulation, link adaptation and multi-antenna transmission techniques. Fast handoff, power control, and inter-sector interference management are embedded in the design to facilitate communication in highly mobile environment. Flexible system configuration allows flexible deployment such as TDD/FDD modes, full/half duplex modes, TDD partitioning, flexible bandwidth, configurable cyclic prefix duration, etc. Topics covered include (1) Superframe (FDD/TDD) structure. In particular the superframe preamble design is discussed in detail to show how system acquisition/determination is done to facilitate flexible system configurations; (2) Adaptive coding and modulation with synchronous HARQ; (3) Multi-antenna transmission techniques including MIMO, precoding, SDMA, beamforming supported by forward link and quasi-orthogonal reverse link; (4) Inter-sector interference management; (5) Fast handoff; and (6) Fast power control.