Haas J. Zygmunt

Cornell University | CU · Department of Electrical and Computer Engineering

Transportation infrastructure experiences distress due to aging, overuse, and climate changes. To reduce maintenance costs and labor, researchers have developed various structural health monitoring systems. However, the existing systems are designed for short-term monitoring and do not quantify structural parameters. A long-term monitoring system t...

This paper studies the statistical characterization of ground-to-air (G2A) and reconfigurable intelligent surface (RIS)-assisted air-to-ground (A2G) communications in RIS-assisted UAV networks under the impact of channel aging. A comprehensive channel model is presented, which incorporates the time-varying fading, three-dimensional (3D) mobility, D...

WiFi sensing technology utilizes Channel State Information (CSI) to analyze human behavior and plays a crucial role in mobile computing. WiFi sensing systems are typically deployed by collecting data in specific known environments, known as closed-set settings. However, in practical deployment, WiFi sensing systems may encounter unknown environment...

This letter considers a UAV aiding communication between a ground transmitter and a ground receiver in the presence of co-channel interference. A discrete-time Markov process is adopted to model the complex nature of the Air-to-Ground (A2G) channel, including the occurrence of Line-of-Sight, Non-Line-of-Sight, and blockage events. Moreover, an adap...

In this paper, we propose a novel adaptive decoding mechanism (ADM) for the unmanned aerial vehicle (UAV)-enabled uplink (UL) non-orthogonal multiple access (NOMA) communications. Specifically, considering a harsh UAV environment, where ground-to-ground links are regularly unavailable, the proposed ADM overcomes the challenging problem of conventio...

A cyber–physical system (CPS) is a multidimensional complex system integrating computing, communication, and control technologies. Because of their key functionality within the system, CPS requires large robustness and security to ensure its reliable operation. Due to its importance in supporting overall system security, anomaly detection (AD) is l...

As interest grows in unmanned aerial vehicle (UAV) systems, UAVs have been proposed to take on increasingly more tasks that were previously assigned to humans. One such task is the delivery of goods within urban cities using UAVs, which would otherwise be delivered by terrestrial means. However, the limited endurance of UAVs due to limited onboard...

Reconfigurable Intelligent Surfaces (RISs) have recently gained significant attention as they enable controlling the wireless propagation environment to improve information transmission with the help of reflective elements. This paper studies a RIS-assisted generalized spatial modulation (GSM) multiple input multiple output (MIMO) system to improve...

In this paper, we propose a novel adaptive decoding mechanism (ADM) for the unmanned aerial vehicle (UAV)-enabled uplink (UL) non-orthogonal multiple access (NOMA) communications. Specifically, considering a harsh UAV environment where ground-to-ground links are regularly unavailable, the proposed ADM overcomes the challenging problem of convention...

In this paper, we propose a novel adaptive decoding mechanism (ADM) for the unmanned aerial vehicle (UAV)-enabled uplink (UL) non-orthogonal multiple access (NOMA) communications. Specifically, considering a harsh UAV environment where ground-to-ground links are regularly unavailable, the proposed ADM overcomes the challenging problem of convention...

In this letter, we propose new channel characterizations for (1) stochastic Terahertz (THz) communications and (2) reconfigurable intelligent surface (RIS)-aided THz systems. Considering a spherical network with stochastic distances between nodes, we derive the exact closed-form expressions for the probability density function (PDF) and the cum...

[ Matlab code with detailed simulation of phase-shifts | https://github.com/trinhudo/Multi-RIS ] In this paper, we study the statistical characterization and modeling of distributed multi-reconfigurable intelligent surface (RIS)-aided wireless systems. Specifically, we consider a practical system model where the RISs with different geometric sizes...

[ Accepted for publication in the IEEE Transactions on Communications ] [ Code: https://github.com/trinhudo/Multi-RIS ] In this paper, we study the statistical characterization and modeling of distributed multi-reconfigurable intelligent surface (RIS)-aided wireless systems. Specifically, we consider a practical system model where the RISs with dif...

As a recently introduced and rapidly accepted new network technology, software defined networking (SDN) provides network providers with operational agility and reduction in capital and operational expenses. As with all new technologies, especially one that offers rich operational flexibility, the lack of experience makes it vulnerable to potential...

[For more information, please visit: https://github.com/trinhudo/Aerial-RIS] In this paper, we propose and investigate an aerial reconfigurable intelligent surface (aerial-RIS)-aided wireless communication system. Specifically, considering practical composite fading channels, we characterize the air-to-ground (A2G) links by Namkagami-m small-scale...

In this paper, we propose and investigate an aerial reconfigurable intelligent surface (aerial-RIS)-aided wireless communication system. Specifically, considering practical composite fading channels, we characterize the air-to-ground (A2G) links by Namkagami-m small-scale fading and inverse-Gamma large-scale shadowing. To investigate the delay-limi...

Intelligent reflecting surface (IRS) is being considered as a prospective candidate for next-generation wireless communication due to its ability to significantly improve coverage and spectral efficiency by controlling the propagation environment. One of the ways IRS increases spectral efficiency is by adjusting phase shifts to perform passive beam...

Intelligent reflecting surface (IRS) is being considered as a prospective candidate for next generation wireless communication due to its ability to significantly improve coverage and spectral efficiency by controlling the propagation environment. One of the ways IRS increases spectral efficiency is by adjusting phase shifts to perform passive beam...

RFID technology is playing an increasingly more important role in the Internet of Things, especially in the dense deployment model. In such networks, in addition to communication, nodes may also need to harvest energy from the environment to operate. In particular, we assume that our network model relies on RFID sensor network consisting of Wireles...

The principle of backscattering has the potential to enable a full realization of the Internet of Things. This paradigm subsumes massively deployed things that have the capability to communicate directly with each other. Based on the types of excitation and receivers, we discriminate four types of backscattering systems: (i) Dedicated Exciter Activ...

Recently, tag-to-tag (T2T) backscattering technique in a passive RFID system has received broad attention due to its superiority for large-scale network applications. If used to implement a Network of Tags, use of T2T communication allows inherent communication parallelism, thus supporting orders of magnitude larger capacity than centralized RFID r...

In this work, we focus on the implementation of reconfigurable distributed multiple-input multiple-output (RD-MIMO) schemes in practical communication environment. Considering RD-MIMO schemes, we raise an original research question, i.e., under what scenario whether we should recruit-thentransmit to multiple mobile receivers simultaneously or just...

We investigate the asymptotic behavior for an overlooked aspect of spectrum-sharing systems when the number of transmit antennas nt at the secondary transmitter (ST) grows to infinity. Considering imperfect channel state information (CSI), we apply the transmit antenna selection and the maximal-ratio combining techniques at the ST and the secondary...

In this paper, we consider a distributed MIMO system with a set of geographically distributed nodes forming a multi-antenna source S, and a set of geographically distributed full duplex (FD) nodes forming a multi-antenna destination D. S and D each forms a transmit and a receive cluster, respectively. D uses FD mode to jam the signal from S at eave...

We propose and study the cooperative MIMO architecture to enable and to improve the secrecy transmissions between clusters of mobile devices in the presence of an eavesdropper with certain location constraint. The cooperative MIMO system in this paper (referred to as Reconfigurable Distributed MIMO) is formed by temporarily activating clusters of n...

Generalized spatial modulation (GSM) is an attractive transmission technique for multiple-input multiple-output (MIMO) systems because of its spectral efficiency and energy efficiency. The maximum likelihood (ML) detector provides the optimal performance for GSM signal detection, but also leads to a high level of detection complexity. In this paper...

Sufficiently strong security and privacy mechanisms are prerequisite to amass the promising benefits of the IoT technology and to incorporate this technology into our daily lives. This paper introduces a novel approach to privacy in networks, an approach which is especially well matched with the IoT characteristics. Our general approach is based on...

Resource allocation plays a critical role in mitigating interference for Device-to-Device (D2D) communications underlaying 5G networks. Although this issue has been explored by various game-theory based approaches, most of the prior studies focus only on the intra-cell scenario, and in the few existing multicell studies, they implicitly assume that...

Energy efficient communication is a fundamental design problem in wireless networks significantly affecting network performance and lifetime of wireless sensor networks (WSN). We introduce encoded sensing – an approach for collaborative encoding and transmission of sensors data – that drastically reduces communication energy expenditure in WSN. Enc...

We propose and study the secrecy cooperative MIMO architecture to enable and to improve the secrecy transmissions between clusters of mobile devices in presence of a multi-antenna eavesdropper. The cooperative MIMO is formed by temporarily activating clusters of the nearby trusted devices, with each cluster being centrally coordinated by its corres...

Although proliferation of electric vehicles (EVs) is associated with significant environmental benefits, these benefits would be forfeited if the associated EV charging systems would rely only on conventional power grid, whose power is mainly generated by fossil-fueled power plants. In contrast, utilizing distributed renewable energy sources will p...

We propose a new distributed MIMO architecture for mobile networks, which we refer to as Reconfigurable Distributed MIMO (RD-MIMO), where the communicating mobile nodes temporarily recruit adjacent nodes to operate as distributed antenna arrays. To best serve the communicating nodes, the node clusters are continuously reconfigured due to the node m...

We study the dynamic energy optimization problem in data centers. We formulate and solve the following offline problem: given a set of jobs to process, where the jobs are characterized by arrival instances, required processing time, and completion deadlines, and given the energy requirements of switching servers ON or OFF, in which time-slot which...

Current trends show that renewable energy production costs continue to decrease with time, so that renewable energy sources (RES) are becoming more suitable as electricity sources. In addition to their environmental benefits, RES are especially appropriate for remote areas, where the expansion of existing power grid is impractical and fuel transpor...

Cloud computing systems enable clients to rent and share computing resources of third party platforms, and have gained widespread use in recent years. Numerous varieties of mobile, small-scale devices such as smartphones, red e-health devices, etc., across users, are connected to one another through the massive internetwork of vastly powerful serve...

Given n source nodes and k relay nodes, we model the optimal relay topology problem allowing for simultaneous optimization of the relay node locations and traffic through the network, so that the overall number of packet retransmissions is minimized. We argue that state-of-the-art models and algorithms for relay placement in wireless networks do no...

In this letter, we investigate the residual link lifetime (RLL) in a mobile ad hoc network, such as a vehicular network. Although, owing to the underlying mobility of the network nodes, the RLLs of adjacent links are highly correlated, yet previous works typically neglected such correlation. In contrast, our study is based on an accurate modeling o...

Quality of Experience (QoE) measures a user's satisfaction with a service delivery. However QoE is a very subjective measure and is context dependent, making it difficult for a service provider to estimate and optimize user's QoE. In this paper, we look at how the provider can maximize QoE by optimizing wireless bandwidth allocation, especially for...

Internet-of-Things (IoT) represents an emerging era of networking that connects a variety of common appliances to one another, as well as with the rest of the Internet, to vastly improve our lives. Despite being significantly resource-constrained, IoT nodes are expected to participate in numerous computationally-intensive security protocols to over...

We study the estimation of residual link lifetime (RLL) in mobile ad hoc networks (MANETs) using the distances between the link's nodes. We first prove that to compute uniquely the RLL, at least four distance measurements are required. We also demonstrate that random measurement errors are the dominant factor in prediction inaccuracy and that syste...

The bandwidth adaptation is the technique that allows the flexibility in bandwidth allocation for a call. Using the bandwidth adaptation technique, the number of call admission in the system can be increased significantly. In this paper we propose a priority based bandwidth adaptation scheme that can release multi-level of bandwidth from the existi...

Cloud computing systems, in which clients rent and share computing resources of third party platforms, have gained widespread use in recent years. Furthermore, cloud computing for mobile systems (i.e., systems in which the clients are mobile devices) have too been receiving considerable attention in technical literature. We propose a new method of...

The increasing interest in using sensor networks in applications for underwater surveillance and oceanic studies underscores the importance of solving the coverage and connectivity issues in 3D wireless sensor networks (WSN). In particular, the problem of supporting full coverage, while ensuring full network connectivity is a fundamental one for su...

Recent advances in MEMS hardware have enabled small-footprint and inexpensive sensors to be deployed in hard-to-access locations and to form wireless sensor networks (WSNs). WSNs are typically mission-oriented networks and offer appealing solutions to a range of practical problems. However, due to the characteristics of WSN, their design principles...

Epidemic routing is considered one of the most effective routing schemes for delay-tolerant networks; indeed, epidemic routing ensures the shortest routing delays. In this chapter, first the epidemic routing is introduced and then the network and mobility models are presented. Finally, we analyze the performance of epidemic routing in two different...

Provisioning of quality of service (QoS) is a key issue in any multi-media system. However, in wireless systems, supporting QoS requirements of different traffic types is a more challenging problem due to the need to simultaneously minimize two performance metrics - the probability of dropping a handover call and the probability of blocking a new c...

Broadcast is a fundamental operation in networks, especially in wireless Mobile Ad Hoc NETworks (MANET). For example, some form of broadcasting is used by all on-demand MANET routing protocols, when there is uncertainty as to the location of the destination node, or for service discovery. Being such a basic operation of the networking protocols, th...

Epidemic routing is considered as one of the most effective routing schemes for delay-tolerant networks; indeed, epidemic routing allows for shortest routing delays. Most of the analytical work in the technical literature concentrates on the latency from the packet creation time until its reception by the destination. However, gaining insight into...

This paper describes a novel approach for collaboration in WSN that substantially reduces energy expenditure in the network by exploiting spatial correlation among nodes. The idea behind the scheme is that the whole range of measurements is partitioned into individual intervals, with each interval assigned to a unique subset of nodes. Each node nee...

Improvement of traffic safety by cooperative vehicular applications is one of the most promising benefits of vehicular ad hoc networks (VANETs). However, to properly develop such applications, the influence of different driving parameters on the event of vehicle collision must be assessed at an early design stage. In this paper, we derive a stochas...

Wireless Body Area Networks (WBANs) promise a significant improvement in the reliability of monitoring and treating people's health. A WBAN comprises a number of intelligent biosensors and actuators that may either be implanted in vivo or mounted on the surface of the human body, and that are capable of wireless communication to one or more externa...

In this paper, the IEEE 802.11 multiple access control (MAC) protocol was modified for use in multi-channel, multi-hop ad hoc networks through the use of a new channel-status indicator. In particular, in the modified protocol, the RTS/CTS dialogue is exchanged on the common access control channel and data packets are transmitted on a selected traff...

In order to perform sensing tasks, most current Intelligent Transportation Systems (ITS) rely on expensive sensors, which offer only limited functionality. A more recent trend consists of using Wireless Sensor Networks (WSN) for such purpose, which reduces the required investment and enables the development of new collaborative and intelligent appl...

In this paper, we propose a simple and practical opportunistic routing algorithm, and we analyze its performance along a multi-hop wireless network path, while considering link-level interference among the network nodes. Through our analysis, we show that our algorithm results in significant improvement in throughput, especially for short-haul path...

The femto-access-point, a low-cost and small-size cellular base-station, is envisioned to be widely deployed in subscribers homes, as to provide high data-rate communications with improved quality of service. As femtocellular networks will co-exist with macrocellular networks, mitigation of the interference between these two network types is a key...

In cooperative networks, transmitting and receiving nodes recruit neighboring nodes to assist in communication. We model a cooperative transmission link in wireless networks as a transmitter cluster and a receiver cluster. We then propose a cooperative communication protocol for establishment of these clusters and for cooperative transmission of da...

Cooperative Networking is a new technology which exploits the massive deployment of nodes in wireless sensor networks. Cooperative Networking synergistically integrates Networking with cluster-based Cooperative Communications to improve reliability and enhance network performance. In this paper, we consider the effect of link-level feedback and ret...

form only given. Information Assurance (IA) grew out of the field of computer network security. However, IA is a much broader term than network security and relates to the managing of the risks associated with the use, processing, storage, and transmission of information. The most basic model of IA relies on three properties: confidentiality, integ...

The lifetime of a wireless network is significantly affected by the energy consumed on data transmission. One approach which allows reduction of the transmission energy consumption is the new networking paradigm - the Delay Tolerant Networks (DTNs). The topology of DTNs consists of nodes with short transmission range, thus allowing the reduction of...

In this paper, we study the problem of radio resource allocation, both transmission rates and transmission powers, so as to maximize the throughput of UWB wireless ad-hoc networks. Our analysis is based on the packet-success function (PSF), which is defined as the probability of a data packet being successfully received as a function of the receive...

Due to the fact that Quality of Service (QoS) requirements are not as stringent for non-real-time traffic types, as opposed to real-time traffic, more calls can be accommodated by releasing some bandwidth from the existing non-real-time traffic calls. If the released bandwidth to accept a handover call is larger than to accept a new call, then the...

Cooperative communication is a promising way to reduce probability of packet loss. The massive deployment of nodes in wireless sensor network renders such networks especially attractive for exploiting the advantage of cooperative diversity. Similarly, when used appropriately, network coding could also improve the probability of correct reception. I...

Integrated femtocell/macrocell networks, comprising a conventional cellular network overlaid with femtocells, offer an economically appealing way to improve coverage, quality of service, and access network capacity. The key element to successful femtocells/macrocell integration lies in its self-organizing capability. Provisioning of quality of serv...

The next generation network aims to efficiently deploy low cost and low power cellular base station in the subscriber's home environment. For the femtocell deployment, frequency allocation among femtocells and macrocell is big concern to mitigate the interference, and to ensure the best use of the expensive spectrum. There are many sources of inter...

The vision behind the personal environment service is that of recreating a user's customized living or working surroundings in accordance with user-defined settings and in response to the user's mobility. Concepts such as ambient intelligence and home networks could be instrumental in realization of PES. Indeed, integration of elements of these tec...

In this paper, we study the application of Linear Network Coding to routing in sparse networks, where the average number of neighbors of a node is less than one. Routing in such networks is facilitated by mobility of the nodes, which create sporadic connections in the network. Due to the long end-to-end packet delivery delays, such networks can sup...

Gossiping, a probabilistic algorithm for network-wide broadcasting, can significantly reduce the number of transmissions in one-to-all message spread. Based on the Continuum Percolation Theory, we develop a novel analytical model of gossiping for wireless ad hoc networks. This model provides an intuitive way for setting the gossiping probability, s...

In some underwater sensor networks, sensor nodes may be deployed at various depths of an ocean making those networks three-dimensional (3D). While most terrestrial sensor networks can usually be modeled as two dimensional (2D) networks, these underwater sensor networks must be modeled as 3D networks. This leads to new research challenges in the are...

Secure routing protocols for mobile ad hoc networks have been developed recently, yet, it has been unclear what are the properties they achieve, as a formal analysis of these protocols is mostly lacking. In this paper, we are concerned with this problem, how to specify and how to prove the correctness of a secure routing protocol. We provide a defi...

We propose an algorithm to predict the link lifetime in MANETs by the unscented Kalman filter (UKF). The algorithm recursively computes the UKF states, modeled as a nonlinear system, using periodically measured distances as inputs. The UKF states are then utilized to compute the estimates of the remaining link lifetime. Evaluation of the proposed a...

The interest in Bluetooth technology has stimu- lated much research in algorithms for topology creation and control of networks comprised of large numbers of Bluetooth devices. In particular, the issue of scatternet formation has been addressed by researchers in a number of papers in the technical literature. This paper is an extension of the work...