Search

Hop count distribution (HCD), generally formulated as a discrete probability distribution of the hop count, constitutes an attractive tool for performance analysis and algorithm design. This paper devotes to deriving an analytical HCD expression for a finite ad hoc network under the minimum hop-count routing protocols. Formulating the node distribution with binomial point process, the network is provided as a bounded area with all nodes randomly and uniformly distributed. Considering an arbitrary pair of source node (SN) and destination node, an innovative and straightforward definition is presented for HCD. In order to derive HCD out, an original mathematical framework, named as the equivalent area replacement method (EARM), is proposed and verified. Under the EARM, HCD is derived by first considering the special case where SN locates at the network center and then extending to the general case where SN is randomly distributed. For each case, the accuracy of our HCD model is evaluated by simulation comparison. Results show that our model matches well with the simulation results over a wide range of parameters. Particularly, the derived HCD outperforms the existing formulations in terms of the Kullback Leibler divergence, especially when SN is randomly distributed. [ABSTRACT FROM AUTHOR]

Resilient control of cyber-physical systems (CPSs) against actuator and/or sensor attacks has been extensively researched. However, the existing research considers actuator attacks and sensor attacks separately and also designs resilient controllers based on complex nonlinear system models caused by unknown actuator and sensor attacks. This increases the difficulty in the analysis, computation, and control of CPSs under attacks. To address this issue, this article introduces an idea to deal with both actuator attacks and sensor attacks together with feedback linearization control. This simplifies the mathematical modeling of attacked CPSs, thus reducing the difficulty of resilient controller design. Then, from the simplified modeling, a composite controller is designed to enhance system resilience. It ensures the dynamic and steady-state performance of CPSs under attacks. Simulation studies are undertaken to demonstrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Multimicrogrid (MMG) systems play an increasingly important role in the smart grid. They come with various potential cyberattacks, which may cause power supply interruption or even human casualties. Therefore, decision-making for timely mitigation of cyberattack risks is highly desirable in the security protection of power systems. However, there is a lack of effective decentralized decision-making strategies that are able to deal with MMG scenarios through distributed consensus. To address this issue, a decentralized consensus decision-making (DCDM) approach is proposed in this article for the security of MMG systems. It achieves decentralized consensus without the need of a trusted authority or central server, making it distinct from existing consensus methods. Meanwhile, it guarantees the consistency and nonrepudiability of consensus results, which are stored on the blockchain in sequence. In each of the distributed agents, the approach consists of a fuzzy static Bayesian game model (FSB-GM) to determine the optimal security strategy and a hybrid consensus algorithm to achieve consensus. The FSB-GM considers the fuzzy preferences of different types of attackers and defenders. The hybrid consensus algorithm is implemented by the fusion improvement of two consensus mechanisms in the blockchain. The effectiveness of the presented approach is demonstrated through a case study on an MMG system. [ABSTRACT FROM AUTHOR]

In this paper, we present measurements and analysis of propagation channels in vehicle-to-infrastructure (V2I) scenarios, which are the basis of designing vehicular communication systems. Firstly, we propose a deterministic geometry-based method to classify V2I links into three types, i.e., line-of-sight beneath (LOS-B), non-LOS (NLOS), and line-of-sight above (LOS-A), based on the environmental features, where roadside row of trees constitute the main obstacles. Secondly, for each link, we investigate the large-scale fading effect on V2I channels, including the path loss exponent and shadowing components. Subsequently, we validate the empirical path loss model using extensive measurements and two classical channel models. The results show a good fit with a near-zero mean and tolerable standard deviation of the estimation error. Finally, we analyze the small-scale fading effects, including fading depth and distance-dependent Ricean K-Factor, which are very important for accurately predicting the required fading margin and link budget. Through the analysis and simulations, this work provides a reference of the V2I channel characteristics for the test, design, and performance analysis of V2I communication systems. [ABSTRACT FROM AUTHOR]

IEEE 802.15.4 is a promising standard that can provide efficient communication quality at low cost and low data rates. This standard has been studied for vehicle-to-infrastructure (V-I) communication in wireless sensor network (WSN)-based vehicular ad hoc network (VANET) applications. To adopt this standard for vehicular communications, link quality metrics must be investigated for topology design and network optimization. In this study, a series of measurements were made with IEEE 802.15.4 radios to identify wireless channel characteristics with regard to antenna height, vehicle velocity, and distance in various vehicular scenarios. The empirical behavior of link communication quality was also investigated in terms of received signal strength, packet error rate (PER), and packet loss distribution (PLD). The empirically measured and experimental results, which have been validated through appropriate analytical modeling, provide valuable insights, as well as guide design decisions and tradeoffs for WSN-based VANET applications. [ABSTRACT FROM PUBLISHER]

Pricing has been widely used to solve network optimization problems. In this paper, we study the case where the network service provider (NSP) has incomplete information about the users, such as the specific user type. Formulating the pricing of the monopolistic NSP and the flow control of the users as a two-level hierarchical game, we first obtain closed-form equilibrium solutions that jointly maximize the benefits of the monopolistic NSP and the users with heterogeneous quality-of-service (QoS) requirements. Then, based on the closed-form solutions, we consider a more general and practical multi-NSP and multiuser model. We further propose a novel one-sided job-hopping matching game to obtain stable NSP-user matching that can optimize network performance in a multi-NSP and multiuser scenario. Simulations demonstrate the effectiveness of the proposed game-theoretic approaches in both the monopolistic and multi-NSP cases. [ABSTRACT FROM AUTHOR]

Vehicle electrification is envisioned to be a significant component of the forthcoming smart grid. In this paper, a smart grid vision of the electric vehicles for the next 30 years and beyond is presented from six perspectives pertinent to intelligent transportation systems: 1) vehicles; 2) infrastructure; 3) travelers; 4) systems, operations, and scenarios; 5) communications; and 6) social, economic, and political. [ABSTRACT FROM PUBLISHER]