INTRODUCTION: Wireless Sensor Network is an interesting technology, which has great deal of node power, which affects the quality of various service parameters. The sensor nodes have been built with fixed energy and spend certain amount of energy for each data tran
INTRODUCTION: The Authors present a new approach to a method of dynamic spectrum management for militarymobile ad hoc network. They propose that data concerning vital signs of tactical radio operators be used as contextinformation for spectrum management. If the operator’s inability to operate and protect the tactical radio is identified,actions (remote control of radio) are taken with the aim to release spectrum resources which used by the radio.Additionally, in this case remote control of radio allows switch the radio to modes used by search and rescue teams andlock the radio for unauthorized person.OBJECTIVES: The primary objective of this study was use vital signs of tactical radio operator’s as context informationfor dynamic spectrum management within MANET.METHODS: Tests for correct detection of vital signs were carried out for data generated on a Hal S3201 adult patientsimulator. Hypotheses about radio operator's vital signs were verified by means of a belief function defined in DempsterShafer theory.RESULTS: Loss vital signs by the operator allows to remote turn off his/her tactical radio while allocating more resourcesto other network users, which allow increasing data throughput.CONCLUSION: Monitoring vital signs of a tactical radio operator enables detecting combat readiness loss which resultsin inability to protect communications and can be used in spectrum management mechanisms.
Remote and rural areas are a challenge to deploy cost-efficient connectivity solutions. 5G technology needslower frequencies, which calls for spectrum sharing for local networks. Spectrum sensing could complementtraditional database approach for spectrum sharing in these areas. This paper studies a windowing based(WIBA) blind spectrum sensing method and compares its performance to a localization algorithm based ondouble-thresholding (LAD). Both methods are based on energy detection and can be used in any band fordetecting rather narrowband signals. Probabilities of detection and false alarm, relative mean square error,number of detected signals and detection distances were evaluated in multipath, multi-signal and rural areachannel conditions. The simulation results show tha the WIBA method is suitable for 5G remote areas, dueto its good detection performance in low signal-to-noise ratios (SNR) with low complexity. Results also showimportance of the detection window selection.
Radio Access Network (RAN) slicing is one of the key enablers to provide the design flexibility and enable 5G system to support heterogeneous services over a common platform (i.e., by creating a customized slice for each service). In this regard, this paper provides an analysis of a Reinforcement Learning (RL)-based RAN slicing strategy for a heterogeneous network with two generic services of 5G, namely enhanced mobile broadband (eMBB) and vehicle-to-everything (V2X). In particular, this paper investigates the RAN slicing by evaluating the proposed scheme under different algorithm configurations (i.e., number of actions of RL) and parameters in order to analyze the performance in terms of metrics such as RL convergence time and to demonstrate the capability of the algorithm to perform an efficient allocation of resources among slices. In addition, this study compares the results obtained by the proposed solution to those obtained with a Proportional Scheme.
In Long Term Evolution (LTE) networks, centroid topology optimization (CTO)-based schemes have been widely used to construct network topologies such that overall network performance is improved. In this paper, we systematically analyze CTO-based schemes and develop new schemes to improve network performance by reconnecting disconnected devices. First, we conduct an investigation of CTO-based schemes to understand their limitations. Then, we propose two schemes, called the Power Control-based scheme and Femto Relaybased scheme, to overcome this limitation in LTE networks, in which CTO-based schemes are implemented. Via intensive performance evaluation using NS3, we validate the effectiveness of our proposed schemes towards addressing the limitations of CTO-based schemes. Our results demonstrate an improvement in LTEnetwork performance above both the unoptimized and CTO-based schemes with respect to throughput, delay, delay standard deviation (DSD), etc.
To address the challenges caused by the time-varying rate requirement for multimedia communicationsessions, we propose a Priority Based Routing and link Scheduling (PBRS) scheme for multi-hop cognitive radio networks. The objective is to minimize disruption to communication sessions due to channel switching as well as to minimize network resource consumption for multimedia applications based on a prioritized routingand resource allocation scheme. PBRS includes a priority based optimization formulation and an efficientalgorithm to solve the problem. The main idea is to allocate the available resource to different types of services with their Quality of Experience (QoE) expectation as well as maintain a priority service queue. Services with higher priority such video conference with cognitive radio expects a lower latency during the communication, whereas services with lower priority such as file transferring could tolerate more interruptions. Based on the different QoE requirements of services, PBRS will decide whether or not to change the routing and link scheduling. If a session has a higher priority than the others, PBRS will maintain its routes, channels, and links to the next timeslot as long as the total white space resource is enough to support all sessions. This eliminates unnecessary channel switching due to rescheduling. Simulation results demonstrate that PBRS effectively reduces channel switching and hence reduce disruption to communication sessions.
In this paper, we introduce an Software Defined Networking (SDN)-based approach to support the network operations of heterogeneous hierarchical multi-domain Mobile Ad hoc Networks (MANETs). Our approach offers several capabilities, including seamlessly interconnecting heterogeneous MANETs, reducing routing decision loads of gateway routers, and managing end-devices at the network edge from the Network Operation Center (NOC) with our SDN Proxy Protocol. To assess the feasibility of our proposed approach, we setup an emulation environment, and implement our designed system via the Constrained Application Protocol (CoAP), additionally integrating OLSRv2, OSPF-MDR, Babel, and others. Based on a set of designed test scenarios, we then carry out an extensive performance evaluation of our approach. Our experimental results show significant network performance improvements at the gateway routers. The SDN Proxy Protocol also outperforms the traditional CoAP-to-CoAP communication when network instability exists.
In this paper, a novel context aware medium access control scheme is proposed for multichannel buffer-aided cognitive networks. The proposed scheme allows management of the delay more efficiently by exploiting the packets’ context. In the proposed multiple access policy, two different context aware approaches for packet prioritization are presented. In the first method, more delay sensitive packets in the primary and secondary networks are given a higher priority compared to delay tolerant packets. In the second proposed prioritization method, shorter packets in the primary and secondary networks are given a higher priority compared to longer packets and are transmitted over channels with lower service time. The average waiting time of the packets and the primary and secondary throughput are derived. Simulation results show that the proposed schemes improve the average waiting time of packets and average throughput compared to other existing MAC policies in cognitive networks.
This paper discusses the regulatory and standardization status of the Licensed Shared Access (LSA), compares it with the US Citizens Broadband Radio Service concept, and reviews results from the ongoing feasibility study in the European Telecommunications Standards Institute on temporary spectrum access for local high-quality wireless networks. Based on comparative analysis, a new LSA evolution concept and functional architecture is proposed, and the early results of the world first LSAevo validation are presented. Introduced system architecture can be applied to 3.4-3.8 GHz band so that fragmentation challenges to take the band into 5G use in the European member states can be solved, while ensuring that the communication of the incumbent users, fixed wireless access, fixed links, and satellite earth stations do not experience any harmful interference. In the end-to-end field trial, local high-quality wireless network use case for an industrial automation Micro-operator is validated.
The majority of existing spectrum prediction models in Cognitive Radio Networks (CRNs) don’t fully explore the hidden correlation among adjacent observations. In this paper, we first develop a novel prediction approach termed high-order hidden bivariate Markov model (H2BMM) for a stationary CRN. The proposed H2BMM leverages the advantages of both HBMM and high-order, which applies two dimensional parameters, i.e., hidden process and underlying process, to more accurately describe the channel behavior. In addition, the current channel state is predicted by observingmultiple previous states. Afterwards, themobility of secondary users is fully considered and we propose an advanced approach based on H2BMM, termed Advanced H2BMM, to accommodate a mobile CRN. Extensive simulations are conducted and results verify that the prediction accuracy is significantly improved using the proposed (H2BMM. The Advanced H2BMM is also evaluated with comparison to H2BMM and results show considerable improvements of H2BMM in a mobile environment. Received on 7 December 2017; accepted on 9 December 2017; published on 12 December 2017
This paper investigates how to increase communication distance of underwater wireless optical communication system.In order to analyze the communication distance of UWOC, the performance of optical transmitter and receiver, underwater channel characterization and modulation schemes were discussed.The communication link model was established based the on Beer-Lambert Law.The suitable transmitter power and the maximum communication were achieved in order to achieve communication rate to 1Mbits/s and bit error rate to 10 -6 .This paper not only provides comprehensive understanding of UWOC, but also aims to provide a theoretical foundation for designing the underwater wireless optical communication system and optimizing the system parameters.
In this paper, we propose a cross-domain optimization (CDO) scheme, which optimizes the MANET topology and enables communication between multiple MANETs via LTE. Particularly, we first deploy a gateway to the center of gravity of all nodes in each MANET so that the network topology is optimized. Thus, the aggregation cost of intra-MANET traffic in the gateway is improved. Likewise, we then deploy an eNodeB in the center of gravity of all gateways to establish communication connections between multiple MANETs via LTE. Then, the aggregation cost of inter-MANET traffic at eNodeBs can be largely reduced because of the minimization of the distances between eNodeBs and gateways, along with a significant performance improvement of inter-MANET communications owing to the superiority of LTE. Vis extensive simulations, we validate the effectiveness of our proposed scheme. Our experimental results demonstrate that the CDO scheme can greatly improve network performance. Finally, we discuss some other issues.
This paper investigates the energy efficiency of Road Side Units (RSUs) by proposing a novel flow and energy management model in Software-Defined Networking (SDN)-based vehicular networks. In the considered scenario, high vehicular mobility and limited coverage area of RSUs cause a degradation in Quality of Experience (QoE) of vehicles and this significantly affects the quality of communication by decreasing the percentage of flow satisfied. In addition, the growth in energy consumption of RSUs leads to inefficient network management. Being inspired from SDN, a centralized controller can schedule RSUs by providing a fair share of network resources and reduce the total energy consumption of RSUs by switching on/off. More specifically, in this paper, the controller classifies to vehicles based on QoE and defines unsatisfactory vehicles. Then the controller estimates the right amount of power level of these vehicles to connect a new assigned RSU. In this manner, RSUs can be scheduled by switching on/off so that the growth in energy consumption of RSUs can be managed. The evaluations show that the proposed model provides a better flow satisfied and throughput by guaranteeing energy efficiency in SDN-based vehicular networks.
In this work, the opportunistic spectrum access (OSA) problem is addressed with stationary and non-stationary Markov multi-armed bandit (MAB) frameworks. We propose a novel index based algorithm named QoS-UCB that balances exploration in terms of occupancy and quality, e.g. signal to noise ratio (SNR) for transmission, for stationary environments. Furthermore, we propose another learning policy, named discounted QoS-UCB (DQoS-UCB), for the non-stationary case. Our contribution in terms of numerical analysis is twofold: i) In stationary OSA scenario, we numerically compare our QoS-UCB policy with an existing UCB1 and also show that QoS-UCB outperforms UCB1 in terms of regret and ii) in non-stationary OSA scenario, numerical results state that proposed DQoS-UCB policy outperforms other simple UCBs and also QoS-UCB policy. To the best of our knowledge, this is the first learning algorithm which adapts to non-stationary Markov MAB framework and also quantifies channel quality information.
Software defined wireless networking is regarded as an emerging technology to enhance spectrum efficiency and improve the overall network performance. In this paper, we summarise the special issue on recent advances in software defined wireless networking. Specifically, this special issue publishes following findings: i) a novel context aware medium access control scheme for multichannel buffer-aided cognitive networks to reduce the delay by exploiting the packets’ contexts; ii) a utility-based uplink scheduling algorithm that accommodates different performance metrics and adapts its decisions based on user-specified profiles by incorporating an intermediary layer between the MAC and network layer; iii) an opportunistic spectrum access (OSA) solution with stationary and nonstationary Markov multi-armed bandit (MAB) frameworks using index based algorithm (called QoS-UCB) which balances exploration in terms of occupancy and quality for transmission for stationary environments and discounted QoS-UCB (DQoS-UCB) for the non-stationary case. These methods have been formally analysed and evaluated using numerical results obtained from extensive simulations.
Reliable wireless communications between vehicles (V2V) and between vehicles and infrastructure (V2I) will play a key role in future transport networks. Where there is overlapping coverage of multiple Radio Access Technologies, with no cooperation between them, a vehicle can use the different technologies simultaneously. This paper proposes an uplink Multi Interface Scheduling System (MISS) located at an intermediate shim layer on the user side, to achieve eÿcient bandwidth aggregation, or lower end-to-end packet delay. MISS aims to find all the available networks that can meet multiple criteria based on user preference and required performance. Simulation results show that safety critical traffic can be prioritized where the resources are insufficient for all the services. Video delivery quality is also improved by prioritizing the most important frames. This algorithm is ideally suited to vehicular networks, where delivery of safety traffic and/or video is an essential requirement.
In this paper, we evaluate the opportunities that Wireless Network Virtualization (WNV) can bring for spectrum sharing by focusing on the regulatory framework that has been deployed by the Federal Communications Commission (FCC) for the 3.5 GHz band. We pair this innovative regulatory approach with another novel arrangement, Wireless Network Virtualization, and thus assess the resulting opportunities from the perspectives of regulation, technology and economics. To this end, we have established a comprehensive foundation for further exploration and development of virtualized networks that would provide significant opportunities for enabling and enhancing current sharing arrangements.
This paper investigates the effect of antenna directivity on the accuracy of fingerprint-based indoor localisation systems. The proposed method adopts received signal strength which was derived by ray tracing techniques applied to 3D indoor model for location determination. Antennas with different radiation patterns and different orientations are implemented for comparative study. Numerical results show that, by utilizing the geometry of the indoor environment, directional antennas can help increase the uniqueness of the fingerprints and hence improve the localisation accuracy.
Fairness of wireless channel access in terms of utilisation and throughput is studied for IEEE 802.11g by using the process algebra PEPA. Three models are presented to describe dif-ferent operating scenarios. Results are derived which demon-strate when and how unfairness might occur, leading to the penalisation of some nodes in a network.
Human body communication (HBC), which uses the human body as a propagation medium, is a promising communication technology in brain-controlled functional electrical stimulation (FES). In order to study the propagation characteristics of HBC channel between intra-brain and body implant, a 45kg pig was employed as an experimental subject in this paper. The channel characteristics of amplitude and group delay were investigated by vector network analyzer (VNA) over different frequencies (from 0.3MHz to 200MHz). A battery powered transmitter and receiver were adopted to study the influence of electrode size and type. Experimental results show that the optimal HBC frequency for brain-controlled FES applications is from 5MHz to 50MHz. Electrode size have little impact on signal transmission in body channel. In addition, signal transmission is insensitive with the electrode type.
