A microgrid is a localized distribution network that consists of electricity users who have access to local renewable and other energy sources. Typically, it is connected to a utility distribution grid but can also function independently. The utility grid plays a crucial role in the nation's economy and security, as well as the well-being of its residents. However, connecting different microgrids to a wider network through a utility's substation can expose them to significant cyber threats. This study examines cybersecurity vulnerabilities in microgrid systems using a testbed approach. By simulating various cyberattack scenarios on a microgrid testbed, we assess the impact of different attack types on microgrid operations, with a particular focus on system stability and communication networks. Attacks such as denial of service, communication hijacking, and others are explored. Our findings highlight significant weaknesses in the communication infrastructure and provide insights into designing microgrids that can effectively address cybersecurity challenges in real-world industrial utility networks.

The area of the state of Oregon has 98,381 square miles, which is the 9th largest in United States. Its population ranks 27th in United States, and most of its population residents in the Willamette valley, a narrow area north to Portland and south to eugene and home to eight of ten most populous cities in Oregon. This implies that most of Oregon are rural areas. It is necessary to design and deploy a portable intelligent system to monitor the danger and protect drivers' safety. In this paper, we will introduce the design of our portable intelligent flooding monitor system. We deploy sensors to roadside and/or vehicles. The flood alert will be sent to central control office or vehicles accessing the network.

For noncooperative networks in which each node is a selfish agent, certain incentives must be given to intermediate nodes to let them forward the data for others. What makes the scenario worse is that, in a multihop noncooperative network, the end points can only observe whether or not the end-to-end transaction was successful or not, but not the individual actions of intermediate nodes. Thus, in the absence of properly designed incentive schemes, rational and selfish intermediate nodes may choose to forward data packets at a very low priority or simply drop the packets, and they could put the blame on the unreliable channel. In this paper, assuming the receiver is a trusted authority, we propose several methods that discourage the hidden actions under hidden information in multihop noncooperative networks with high probability. We design several algorithmic mechanisms for a number of routing scenarios such that each selfish agent will maximize its expected utility (i.e., profit) when it truthfully declares its type (i.e., cost and its actions) and it truthfully follows its declared actions. Our simulations show that the payments by our mechanisms are only slightly larger than the actual cost incurred by all intermediate nodes.

A sensor in wireless sensor networks (WSNs) periodically produces data as it monitors its vicinity. The basic operation in such a network is the systematic gathering (with or without in-network aggregation) and transmitting of sensed data to a base station for further processing. A key challenging question in WSNs is to schedule nodes' activities to reduce energy consumption. In this paper, we focus on designing energy-efficient protocols for low-data-rate WSNs, where sensors consume different energy in different radio states (transmitting, receiving, listening, sleeping, and being idle) and also consume energy for state transition. We use TDMA as the MAC layer protocol and schedule the sensor nodes with consecutive time slots at different radio states while reducing the number of state transitions. We prove that the energy consumption by our scheduling for homogeneous network is at most twice of the optimum and the timespan of our scheduling is at most a constant times of the optimum. The energy consumption by our scheduling for heterogeneous network is at most ¿ (log Rmax/Rmin) times of the optimum. We also propose effective algorithms to construct data gathering tree such that the energy consumption and the network throughput is within a constant factor of the optimum. Extensive simulation studies show that our algorithms do considerably reduce energy consumption.

Sleep scheduling is a widely used mechanism in wireless sensor networks (WSNs) to reduce the energy consumption since it can save the energy wastage caused by the idle listening state. In a traditional sleep scheduling, however, sensors have to start up numerous times in a period, and thus consume extra energy due to the state transitions. The objective of this paper is to design an energy efficient sleep scheduling for low data-rate WSNs, where sensors not only consume different amounts of energy in different states (transmit, receive, idle and sleep), but also consume energy for state transitions. We use TDMA as the MAC layer protocol, because it has the advantages of avoiding collisions, idle listening and overhearing. We first propose a novel interference-free TDMA sleep scheduling problem called contiguous link scheduling, which assigns sensors with consecutive time slots to reduce the frequency of state transitions. To tackle this problem, we then present efficient centralized and distributed algorithms that use time slots at most a constant factor of the optimum. The simulation studies corroborate the theoretical results, and show the efficiency of our proposed algorithms.

This paper presents novel distributed algorithms for scheduling transmissions in multi-hop wireless networks. Our algorithms generate new schedules in a distributed manner via simple local changes to existing schedules. Two classes of algorithms are designed: one assumes that the location information of all wireless nodes are known, and the other does not. Both classes of algorithms are parameterized by an integer k (called algorithm-k). We show that algorithm-k that uses geometry location achieves (1 - 2/k)2of the capacity region, for every k ges 3; algorithm-k which does not use geometry location achieves 1/rho of the capacity region, for every k ges 3 and a constant rho depending on k. Our algorithms have small worst-case overheads. Both classes of algorithms can generate a new schedule by requiring communications within Theta(k) hops for every node, which can be implemented by letting each node transmit at most O(k) messages. The parameter k explicitly captures the tradeoff between control overhead and the throughput performance of any scheduler. Additionally, the class of algorithms with known geometry location of nodes can And a new schedule in time Theta(k2Delta), where Delta is the minimum mini-time-slots such that each of the n nodes can communicate with its neighbors once, which is the minimum time-slots required by any scheduling algorithm.

In this paper, we address the problem of joint channel assignment, link scheduling, and routing for throughput optimization in wireless networks with multi-radios and multi-channels. We mathematically formulate this problem by taking into account the interference, the number of available radios the set of usable channels, and other resource constraints at nodes. We also consider the possible combining of several consecutive channels into one so that a network interface card (NIC) can use the channel with larger range of frequencies and thus improve the channel capacity. Furthermore, we consider several interference models and assume a general yet practical network model in which two nodes may stillnotcommunicate directly even if one is within the transmission range of the other. We designed efficient algorithm for throughput (or fairness) optimization by finding flow routing, scheduling of transmissions, and dynamic channel assignment and combining. We show that the performance, fairness and throughput, achieved by our method is within a constant factor of the optimum. Our model also can deal with the situation when each node will charge a certain amount for relaying data to a neighboring node and each flow has a budget constraint. Our extensive evaluation shows that our algorithm can effectively exploit the number of channels and radios. In addition, it shows that combining multiple channels and assigning them to a single user at some time slots indeed increases the maximum throughput of the system compared to assigning a single channel.

Energy efficient routing and power control techniques in wireless ad hoc networks have drawn considerable research interests recently. In this paper, we address the problem of energy efficient reliable routing for wireless ad hoc networks in the presence of unreliable communication links or devices or lossy wireless link layers by integrating the power control techniques into the energy efficient routing. We consider both the case when the link layer implements a perfect reliability and the case when the reliability is implemented through the transport layer, e.g., TCP. We study the energy efficient unicast and multicast when the links are unreliable. Subsequently, we study how to perform power control (thus, controlling the reliability of each communication link) such that the unicast routings use the least power when the communication links are unreliable, while the power used by multicast is close to optimum. Extensive simulations have been conducted to study the power consumption, the end-to-end delay, and the network throughput of our proposed protocols compared with existing protocols.

The capacity of a wireless network has been widely studied in the literature, including the capacity for unicast and the capacity for broadcast. In this paper, we studied the capacity of a wireless network for broadcast. Previous studies on broadcast capacity either assume that all links in the wireless network has the same channel capacity, or assume that the transmission ranges of a wireless node can be arbitrarily large. In this paper we derive analytical upper bounds and lower bounds on broadcast capacity of a wireless network when all nodes in the network has the same bounded transmission power P and all nodes are placed in a square of side-length a. When the fixed data rate channel is used (each node can send W bits/second to nodes within its transmission range if no interference happened), we prove that the broadcast capacity is Θ(W) under the physical interference model. When the Gaussian channel capacity is used, we show that the total broadcast capacity is only Θ((α√log n/n)−βwhen α√log n/n → ∞. When a α√log n/n → O(1), we show that the broadcast capacity is Θ(1). We also generalize our results to multicast capacity for physical interference model.

For multi-hop ad hoc networks formed by individually owned nodes, the endpoints can only observe whether or not the end-to-end transaction was successful or not, but not the individual actions of intermediate nodes. Consequently, in the absence of properly designed incentive schemes, rational (i.e., selfish) intermediate nodes may choose to forward data packets at a very low priority or simply drop the packets at all, and it could put the blame on the unreliable wireless channel. Using a principal-agent model, we propose several efficient methods that can eliminate the hidden actions under hidden information in multi-hop wireless networks with high probability. We design several algorithmic mechanisms for a number of routing scenarios such that each selfish agent will maximize its utility (i.e., profit) when it truthfully declares its type (i.e., cost and its actions) and it truthfully follows its declared actions. Our simulations show that the payment by our mechanisms is only slightly larger than the actual cost incurred by all intermediate nodes.

Energy efficient routings and power control techniques in wireless networks have drawn considerable research interests recently. In this paper, we address the problem of energy efficient reliable routing in wireless networks in the presence of unreliable communication links or devices or lossy wireless link layers by integrating the power control techniques into the energy efficient routing. We study both the case when the link layer implements a perfect reliability and the case when the reliability is implemented through the transport layer, e.g., TCP. We study the energy efficient unicast when the links are unreliable. Subsequently, we study how to perform power control (thus, controlling the reliability of each communication link) such that the unicast routings use the least power when the communication links are unreliable. We presented both centralized algorithms and distributed algorithms for all the questions we studied. We conducted extensive simulations to study the power consumption, the end-to-end delay, and the network throughput of our protocols compared with existing protocols