Journal of High Speed Networks - Volume 24, issue 4

Authors: Das, Smita | Kanti DebBarma, Mrinal

Article Type: Research Article

Abstract: Now-a-days Wireless Sensor Networks (WSNs) have massive significance in different surveillance related applications where coverage plays an important role. While arranging the sensor nodes in a large scale WSN, covering the region of interest (ROI) is a complicated job and this quality of coverage is compromised in the presence of coverage holes. As holes can cause permanent or temporary interruption in sensing or in communicating task, therefore detection of holes in a coverage area is an essential job. In this paper, we first construct a Delaunay Triangle on the basis of node location information. Then we propose an algorithm based …on the property of empty circle to recognize whether coverage hole is present or not in the given ROI of a large scale WSN. Also, we have estimated the area of the coverage-hole based on computational geometry. We have shown the correctness of the algorithm based on the theoretical proofs. Simulations are also conducted to show the effectiveness of the algorithm for coverage-hole detection and area estimation (CHDAE). Show more

Keywords: Wireless sensor networks, sensor nodes, coverage, coverage hole-detection, empty circle, Delaunay Triangulation

DOI: 10.3233/JHS-180595

Citation: Journal of High Speed Networks, vol. 24, no. 4, pp. 281-296, 2018

Authors: Li, Yongqiang | Wang, Zhong | Wang, Qingwen | Fan, Qinggang

Article Type: Research Article

Abstract: The routing protocol is a key technology in ad hoc networks. Most of these protocols use the flooding mechanism for routing discovery. But the flooding mechanism easily leads to the broadcast storm problem. In addition, the rapidly changing locations of nodes in mobile ad hoc networks leads to dynamic changes in network topology and frequent disconnection of communication links between nodes. To alleviate the broadcast storm problem, we propose an adaptive multipath routing protocol based on game theory (GMAR). GMAR uses game theory to optimize the routing discovery process, which reduces redundant retransmissions, contention, and collisions between neighboring nodes. GMAR …also increases link stability by using a multipath mechanism to adapt to dynamic network topology. The simulation results demonstrate that GMAR reduces the average end-to-end delay and the average number of packet losses per node and improves average throughput. Show more

Keywords: Ad hoc network, game theory, multipath, rebroadcast probability

DOI: 10.3233/JHS-180596

Citation: Journal of High Speed Networks, vol. 24, no. 4, pp. 297-310, 2018

Authors: Zou, Yazhou | Xiang, Xin | Yin, Liyan | Zhang, Jingyi | Wang, Rui

Article Type: Research Article

Abstract: In a full-duplex system where correlation exists between self-interference signal and useful signal, direct radio frequency (RF) coupling cancellation structure, which is based on the minimum mean square error (MMSE) criterion, is adopted to conduct self-interference cancellation; however, such cancellation damages the useful signal. In regards to this problem, this paper designs a new RF cancellation scheme: (1) On the basis of cancellation structure, phase shifter controlled by error signal power is thereby introduced to shift the phases of transmitted signal, decreasing the correlation of self-interference signal and useful signal; (2) New Time-varying Step-size Normalized Least Mean Square (NTVSSNLMS) algorithm, …which utilizes the auto-correlation and time parameters t of real-time error signal to cooperatively control the step factor μ ( t ) , is proposed to adjust the attenuator weight vectors, in order to assure a high interference cancellation ratio (ICR ) and satisfy the requirements of phase shifter on algorithm convergence performance at the same time. Simulation results indicate that the new RF cancellation scheme can increase the ICR , while effectively reducing the damages on the useful signal simultaneously. Show more

Keywords: Full-duplex, radio frequency cancellation, correlation, NTVSSNLMS algorithm

DOI: 10.3233/JHS-180597

Citation: Journal of High Speed Networks, vol. 24, no. 4, pp. 311-325, 2018

Authors: Liu, Yi | Ozera, Kosuke | Matsuo, Keita | Ikeda, Makoto | Barolli, Leonard

Article Type: Research Article

Abstract: In this work, we present a distributed event-based awareness approach for P2P groupware systems. We present two fuzzy-based systems for improving peer Awareness and Group Synchronization according to four parameters: Activity Awareness (AA), Sustained Communication Time (SCT), Group Synchronization (GS) and Number of Failed Tasks (NFT). Then, we use fuzzy-based model to decide Peer Coordition Quality (PCQ).We call the proposed systems: FPCQS1 and FPCQS2. We make a comparison study between FPCQS1 and FPCQS2. From the simulations results, we conclude that with increasing of the NFT, the PCQ is decreased. When AA, GS and SCT are high, the PCQ is high. …The proposed systems can choose reliable peers with good peer coordination quality in mobilePeerDroid mobile system. Comparing the complexity, the FPCQS2 is more complex than FPCQS1. However, FPCQS2 considers also the NFT, which makes the system more reliable. Show more

Keywords: Peer awareness, group synchronization, MobilePeerDroid system, fuzzy logic, fuzzy-based systems

DOI: 10.3233/JHS-180598

Citation: Journal of High Speed Networks, vol. 24, no. 4, pp. 327-343, 2018

Authors: Shareef, Zayd Ashraf | Hussin, Masnida | Abdullah, Azizol | Muhammed, Abdullah

Article Type: Research Article

Abstract: WiMAX networks offer quality assurance for various communication services, such as Voice over IP (VoIP), Video on Demand (VoD), File Transfer Protocol (FTP), and Hyper Text Transfer Protocol (HTTP). Over the past few years, communication services, such as streaming audio, video, and multimedia for residential and business users, have experienced rapid growth. This expansion of services causes traffic communication to suffer from congestion and become vulnerable. A scheduling approach, which aims to improve user satisfaction, has thus become more significant for wireless infrastructures. In this work, we present Class-Based QoS Scheduling (CBS), which provides QoS assurances in WiMAX network communication. …The proposed scheduling approach focuses on downlink-stream traffic communication to achieve high network performance and QoS guarantees. CBS consists of the three main functions of priority elevation, virtual ranking queues, and class-based packet scheduling. The CBS approach supports diverse types of traffic services to guarantee variability in the communication services of WiMAX. The simulation results illustrated that the proposed scheduling approach exhibited considerably better performance in terms of the throughput and the delay than the other scheduling schemes. Show more

Keywords: WiMAX, traffic services, packet scheduling, queues, priorities, quality of service, delay & throughput

DOI: 10.3233/JHS-180599

Citation: Journal of High Speed Networks, vol. 24, no. 4, pp. 345-362, 2018

Authors: De Prisco, Roberto | De Santis, Alfredo | Mannetta, Marco

Article Type: Research Article

Abstract: Hardware Security Modules (HSM) are special devices designed for cryptographic operations and cryptographic keys management. The keys are stored internally to the HSM and never exposed. All the operations involving the keys are performed inside the HSM and only the result is given outside. To store all the keys that have to be managed an HSM must have a lot of storage space. Large data centers that handle millions of cryptographic keys needed to host many HSMs. Related costs are directly proportional to the number of HSMs used: hardware, energy consumption, network hosting, network speed, management. In this paper we …present two approaches that allow to save space for storing keys in an HSM, thus reducing the number of needed HSMs and consequently all other related costs. Cost savings comes at the expense of computation time. Show more

Keywords: Hardware security modules, reducing costs, cryptographic keys management

DOI: 10.3233/JHS-180600

Citation: Journal of High Speed Networks, vol. 24, no. 4, pp. 363-373, 2018