IEEE Journal on Selected Areas in Communications

We propose a secure scheme for wireless network coding, called the algebraic watchdog. By enabling nodes to detect malicious behaviors probabilistically and use overheard messages to police their downstream neighbors locally, the algebraic watchdog delivers a secure global self-checking network. Unlike traditional Byzantine detection protocols which are receiver-based, this protocol gives the send... View full abstract»

Mobile Ad-Hoc Networks (MANETs) are particularly useful and well-suited for critical scenarios, including military, law enforcement as well as emergency rescue and disaster recovery. When operating in hostile or suspicious settings, MANETs require communication security and privacy, especially, in underlying routing protocols. Unlike most networks, where communication is based on long-term identit... View full abstract»

We present a novel framework for spatial routing through difficult terrains with possibly untrustworthy regions in tactical mobile ad hoc networks. We describe a protocol, named "Reliability Map Routing" (RMR), which uses end-to-end Quality of Service metrics that include spatial reliability and trust. The RMR protocol reactively discovers routes over spatial cells whose local reliabilities are di... View full abstract»

We propose a novel cooperative positioning algorithm that fuses information from satellites and terrestrial wireless systems, suitable for GPS-challenged scenarios. The algorithm is fully distributed over an unstructured network, does not require a fusion center, does not rely on fixed terrestrial infrastructure, and is thus suitable for ad-hoc deployment. The proposed message passing algorithm, n... View full abstract»

The problem of cognitive access of multiple primary channels by multiple cognitive users is considered. The primary transmission on each channel is modeled by a continuous time Markov on-off process. Cognitive access of the primary channels is realized via channel sensing. Each cognitive user adopts a slotted transmission structure, senses one channel in each slot and makes the transmission decisi... View full abstract»

Joint optimization of network coding and Aloha-based medium access control (MAC) for multi-hop wireless networks is considered. The multicast throughput with a power consumption-related penalty is maximized subject to flow conservation and MAC achievable rate constraints to obtain the optimal transmission probabilities. The relevant optimization problem is inherently non-convex and hence difficult... View full abstract»

Multi-packet reception (MPR) has recently received attention for use in military wireless ad hoc networks because of the potential to greatly improve spatial reuse. However, MPR typically requires complicated hardware that makes it prohibitive to implement in many current military platforms. An alternative, cross-layer approach is to use an overlapped transmission technique, in which multiple tran... View full abstract»

In this paper, we consider a network of stationary nodes that rely on mobile nodes to transport data between them. We assume the mobile nodes can control their mobility pattern to respond to traffic loads, as well as satisfy some other secondary objectives, such as surveillance requirements. We study this problem in the framework of cost minimization, where we derive a dual iterative algorithm tha... View full abstract»

The solar blind ultraviolet (UV) scattering channel makes non-line-of-sight UV communications very attractive for military applications, particularly for communication on-the-move with low probability of detection and low probability of interception. Despite significant research effort on the UV physical layer, work on protocol design at the upper layers is quite limited. We consider a mobile ad h... View full abstract»

We analyze the performance of underwater acoustic ad-hoc networks in the presence of interference. We assume a uniform distribution of nodes over a finite area, and focus for simplicity on a two-dimensional network. The node-to-node channel is modeled using frequency dependent path loss and Ricean fading. We adopt a communication theoretic approach and study the sustainable number of hops through ... View full abstract»

Due to the growing importance of coastline surveillance and protection, underwater communication is playing an increasingly important role in military networks. As compared to terrestrial networks, large propagation delays and low data rates are fundamental characteristics of underwater communication. Furthermore, due to some key differences in the factors causing fluctuations in the quality of th... View full abstract»

We consider streaming over a blockage channel with long feedback delay, as arises in, e.g., real-time satellite communication from a comm-on-the-move (COTM) terminal. For this problem, we introduce a definition of delay that captures the real-time nature of the problem, which we show grows at least as fast as O(log(k)) for memoryless channels, where k corresponds to the number of packets in the tr... View full abstract»

The geographical location of Internet IP addresses is important for academic research, commercial and homeland security applications. Thus, both commercial and academic databases and tools are available for mapping IP addresses to geographic locations. Evaluating the accuracy of these mapping services is complex since obtaining diverse large scale ground truth is very hard. In this work we evaluat... View full abstract»

Low probability of intercept (LPI) communication generally relies on the presence of noise to obfuscate a covert signal through the use of spectral spreading or hopping. In contrast, this paper addresses the use of ambient interference from other man-made emissions as a means to mask the presence of covert communication. Specifically, the high power, wide bandwidth, and repeating structure of puls... View full abstract»

The secure transmission of information in wireless networks without knowledge of eavesdropper channels or locations is considered. Two key mechanisms are employed: artificial noise generation from system nodes other than the transmitter and receiver, and a form of multi-user diversity that allows message reception in the presence of the artificial noise. We determine the maximum number of independ... View full abstract»