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In this paper, we exploit mutual cooperation between primary and secondary users to reduce delay in packet transmission in a cognitive network. More formally, we present a delay optimization problem based on the cooperation model and show that the problem is NP-Hard. The mutual benefit through cooperation is analyzed using a time dependent priority queueing system. Analytical simulation results are...
The cognitive radio (CR) nodes in a cognitive radio network (CRN) do not have license to use specific spectrum band. Instead, they use the spectrum bands of the licensed primary users (PU) without interfering with the PU. When the PU becomes active, interfering CRs should leave to another available spectrum band within the PU's tolerable interference delay (TID). Therefore, CRN operates over wide...
Jammer can jeopardize the dependability of wireless networks, and jammer's position information allows the network to cope with jamming leveraging varieties of defense strategies. Thus, in this paper, we address the problem of localizing jammer. Prior work relies on indirect measurements derived from jamming effects, which makes it difficult to accurately localize jammer. We localize jammer by directly...
The high vulnerability of the wireless sensor nodes to jamming arises from the low resilience and easy differentiability of protocol control messages, and the high predictability of node wakeup schedules. In this paper, we propose Jam-Buster — a jam-resistant solution for WSN, orthogonal to the existing antijamming solutions, that increases resilience by using multi-block payloads, eliminates differentiation...
TCP over Mobile Ad-hoc Networks (MANETs) is challenging due to frequent route breaks, high random errors, and DATA-ACK interference. Network coded multipath approaches have been shown in several previous studies to be an effective transmission paradigms in disruptive networks. However, most of the previous studies either have no adaptive redundancy control or rely on theoretical models that require...
The recent increase in number and complexity of wireless sensor networks (WSN)-based deployments made evident the limits of traditional hardware platforms designed to work in a controlled environment (laboratory) for a limited amount of time. The need for high-performance, low-power, flexible and scalable hardware platforms able to work in real-world (possibly harsh) environments led us to design...
GeoSocial Networks (GSNs) are online social networks centered on the location information of their users. Users “check-in” their location and use it to acquire location-based special status (e.g., badges, mayorships) and receive venue dependent rewards. The strategy of rewarding user participation however makes cheating a profitable behavior. In this paper we introduce XACT, a suite of venue-oriented...
Asynchronous, receiver-driven communication methods are suited to wireless mesh networks with high node density and low data generation frequency. In such networks, however, control packet collisions between hidden terminals can degrade performance. We propose collision avoidance techniques that improve packet collection rates and delay, and that furthermore decrease power consumption.
This demo will demonstrate implementation of a secured EMR (Electronic Medical Record) system that can be used by Physicians, Nurses, Patient Care Technician and Dietician in a Dialysis Center setting. Although substantial work has been done for applications using a desktop browser, only few operations have been implemented on mobile devices. The line between the native and web application development...
Compressive Sampling (CS) is a powerful sampling technique that allows accurately reconstructing a compressible signal from a few random linear measurements. CS theory has applications in sensory systems where acquiring individual samples is either expensive or infeasible. A Wireless Sensor Network (WSN) is a distributed sensory system comprised of resource-limited sensor nodes. Transferring all the...
We consider a cognitive radio scenario where the communication between two secondary users (SUs) exploits opportunistic spectrum access (OSA) over a wireless channel licensed to primary users (PUs). Assuming a slotted MAC over a single frequency channel and imperfect spectrum sensing, we address the problem of determining the packet size and Forward Error Correction (FEC) coding rate that maximize...
Delay Tolerant Networking (DTN) enables transfer of data where conventional network protocols fail to deliver data because no continuous end-to-end connectivity is available. While the Bundle Protocol (BP) has been established as the standard DTN protocol in many application areas, Wireless Sensor Networks (WSN) often use proprietary protocols with a subset of the BP features. In this paper we use...
The openness of the Android operating system increased the number of applications developed, but it also introduced a new propagation vector for mobile malware. We model the propagation of mobile malware using epidemiology theory and study the problem as a function of the underlying mobility models. We define the optimal approach to heal an infected system with the help of a set of static healers...
The inclusion of embedded sensors in mobile phones, and the explosion of their usage in people's daily lives provide users with the ability to collectively sense the world. The collected sensing data from such a mobile phone enabled social network can be mined for users' behaviors and their social communities, and to support a broad range of applications including mobile healthcare systems. However,...
Fair resource allocation for end-to-end flows is an important yet challenging problem in multi-hop wireless networks. Recent research on fair resource allocation is mainly based on the assumption of convex resource regions, which has been theoretically proven untrue. Thus, the definition of fairness in IEEE 802.11 is intriguing for two reasons: non-convexity of the IEEE 802.11, and the intrinsically...
Underwater sensor networks have become an important area of research with many potential practical applications. Given impairments of optical and radio propagation, acoustic communication is used for underwater networking, which translates into variable and long propagation delays, low data rates, long interference ranges and significant fluctuations in terms of link quality over time. A complete...
The RFID technology greatly improves efficiency of many applications including inventory control, object tracking, and supply chain management. In such applications, it is common that new objects are added into the system or existing objects are misplaced in wrong regions. When this happens, fast and complete identification of such tags is very important. We name this problem unknown tag identification,...
The limited battery capacity of sensor nodes has become the biggest impediment to wireless sensor network (WSN) applications. Two recent breakthroughs in the areas of wireless energy transfer and rechargeable lithium batteries promise the use of mobile vehicles, with high volume batteries, as mobile chargers that transfer energy to sensor nodes wirelessly. In this paper, for the first time, we envision...
This paper presents a novel distributed scheme for the dynamic construction and management of spontaneous social communities (SSCs) of mobile users in ad hoc networks. A novel model for SSCs that captures their unique dynamic nature, in terms of community structure and interest in different hot-topics over time is first presented. These time-varying interests are represented through a distributively...
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