High-speed Mobile Research Articles

Pricing-based interference management scheme in LTE-V2V communication with imperfect channel state information

In this paper, an effective LTE-V2V (long-term-evolution vehicle-to-vehicle) communication system is studied, where the uplink channel of the cellular user equipment (CUE) is reused by the multiple V2V links. Considering the co-channel interference caused by channel reusing between CUE and V2V links, a pricing framework of interference management for V2V links and CUE is proposed. In the LTE-V2V communication networks, the base station (BS) protects the serving CUE by pricing the cross-tier interference caused by V2V links. A Stackelberg game is presented to model the interaction between the BS and V2V links. In order to ensure the communication quality of CUE, the total interference generated by V2V links has to be lower than the interference threshold. Specifically, the BS prices the tolerable interference to maximize its revenue. For the given prices, the V2V links competitively adapt their power allocation strategies to maximize the individual utility. Two pricing iterative algorithms, uniform pricing scheme and the non-uniform pricing scheme, are proposed to incorporate with the theory of noncooperative game, in order to analyze the competition between V2V links. In addition, the time-varying characteristics of vehicle communication are considered due to the high-speed mobility of the V2V users. The imperfect channel state information (CSI) fading model is constructed with the large-scale fading and small-scale fading jointly. Numerical simulation results validate the reliability and effectiveness of the proposed algorithms.

GCH-MV: Game-Enhanced Compensation Handover Scheme for Multipath TCP in 6G Software Defined Vehicular Networks

The latest developments in terms of self-driving technologies have increased the demand for high quality data transmission in vehicular networks. However, frequent handovers among the Road Side Units (RSUs) cause degradation of data transmission performance, especially in the context of high-speed mobility. In order to address this problem, a novel game-enhanced compensation handover scheme (GCH-MV) for multipath TCP in 6G software defined vehicular networks is proposed. An innovative system architecture which integrates 6G communication solutions, SDN and multipath techniques is presented. GCH-MV redesigns the fluid model of Multipath TCP (MPTCP) to compensate for the declining throughput by using multiple paths. GCH-MV transfers traffic quickly between different paths, adapting the transmission to path quality and maintain high throughput. In addition, an innovative game-based optimal candidate RSU selection algorithm, employed by GCH-MV during the handover process, is also introduced. GCH-MV uses these solutions to achieve its goal to mitigate the negative impact of handover as much as possible and make the handover process smooth and transparent. Experimental results show how GCH-MV outperforms the existing solutions in terms of several quality of service (QoS) metrics, addressing efficiently the data transfer quality problem during handover in highly mobile vehicular networks.

ARFV: An Efficient Shared Data Auditing Scheme Supporting Revocation for Fog-Assisted Vehicular Ad-Hoc Networks

With the technology of data storage and shared services in the cloud, users can easily share data or revoke from their groups. To ensure the accuracy of the shared data, the key is used for group users to calculate the authenticators of the shared data and audit the data's integrity remotely. However, high-speed mobile terminals have posed challenges to key management in Vehicle Ad-hoc networks (VANETs). Besides, to maintain the integrity of the shared data, the computation and communication overheads must be increased in the revocation process when a vehicle user is removed from a group. For such, a new shared data auditing scheme is proposed in this paper, which supports user revocation by combining the existing certificateless signcryption method with a fog architecture. This scheme improves the efficiency of auditing and user revocation since it reduces many time-consuming operations, as well as features such as public auditing, mutual authentication, efficient and secure revocation are presented. Security analysis and experimental results demonstrate that the proposed scheme is both correct and safe, has more comprehensive functions and better efficiency than other existing ones.

Cooperation Between LDM-Based Terrestrial Broadcast and Broadband Unicast: On Scalable Video Streaming Applications

This article investigates the reliability gain of broadcast (BC)/broadband (BB) cooperation for mobile scalable video streaming. A specific form of BC-BB cooperation is introduced, which is referred to as cooperative casting. The proposed system primarily utilizes a BC transmission for streaming, while BB backup transmissions are requested whenever the BC signal is not decodable. For BC deliveries in this system, a cross-layer collaboration between scalable video coding (SVC) and layered-division multiplexing is used to improve spectral efficiency by coupling their hierarchical structures. In this end, in tandem with designing the uplink requesting rules based on channel status, delivery performance of the cooperative casting is analytically evaluated in a probabilistic framework. The system design and analyses presented in this article focus on the service continuity in a mobile and time-varying channel, where the physical aspects, such as delayed unicast response and inter-carrier interference, are carefully taken into account. Compared to the standalone network transmissions, the cooperative casting is numerically verified to better prevent the delivery failures in high-speed mobile channels, especially when the SVC layer-combined (full-scale video) service is intended. Furthermore, it is also shown that relaxing the criteria for the BB stream requesting can reduce delivery failures substantially, while it increases transmission redundancy.

Adaptive Traffic Engineering Based on Active Network Measurement Towards Software Defined Internet of Vehicles

With the rapid development of urbanization, enormous amounts of vehicular services have been emerging and challenge both the architectures and protocols of the Internet of Vehicles. The high-speed mobility features of nodes in the vehicular networks changes the network topology frequently, resulting in low routing efficiency, and higher packet loss. In this article, we utilize software-defined networking (SDN) technology to decouple the network control plane from the data forwarding plane, and divide the vehicular networks into three functional layers: data, control, application layers. Based on the proposed network architecture, we propose an adaptive traffic engineering (TE) mechanism to guarantee the V2V continuous traffic in vehicular networks with high-speed mobile vehicles or dynamic network topology. In particular, the proposed TE is based on a proposed active network measurement mechanism under the assistance of the centralized management ability of the SDN technique. The proposed active network measurement approach is a greedy approach where the next hop determination for the measurement packet takes multiple link reliability factors (e.g., the delay, the length, the packet error rate, the neighbors, etc.) into account. Then, we utilize the artificial bee colony (ABC) algorithm to optimize the TE mechanism that can be deployed and executed in the SDN controller. By the proposed TE mechanism, multiple candidate end-to-end paths can be concurrently measured, and the optimal data forwarding path can be adaptively switched. Simulation results demonstrate that our approach performs better than some recent research outcomes, especially in the aspect of performing reliable data forwarding (almost 5% better than the compared objects).

Distributed Artificial Intelligence-as-a-Service (DAIaaS) for Smarter IoE and 6G Environments

Artificial intelligence (AI) has taken us by storm, helping us to make decisions in everything we do, even in finding our “true love” and the “significant other”. While 5G promises us high-speed mobile internet, 6G pledges to support ubiquitous AI services through next-generation softwarization, heterogeneity, and configurability of networks. The work on 6G is in its infancy and requires the community to conceptualize and develop its design, implementation, deployment, and use cases. Towards this end, this paper proposes a framework for Distributed AI as a Service (DAIaaS) provisioning for Internet of Everything (IoE) and 6G environments. The AI service is “distributed” because the actual training and inference computations are divided into smaller, concurrent, computations suited to the level and capacity of resources available with cloud, fog, and edge layers. Multiple DAIaaS provisioning configurations for distributed training and inference are proposed to investigate the design choices and performance bottlenecks of DAIaaS. Specifically, we have developed three case studies (e.g., smart airport) with eight scenarios (e.g., federated learning) comprising nine applications and AI delivery models (smart surveillance, etc.) and 50 distinct sensor and software modules (e.g., object tracker). The evaluation of the case studies and the DAIaaS framework is reported in terms of end-to-end delay, network usage, energy consumption, and financial savings with recommendations to achieve higher performance. DAIaaS will facilitate standardization of distributed AI provisioning, allow developers to focus on the domain-specific details without worrying about distributed training and inference, and help systemize the mass-production of technologies for smarter environments.

Performance of non‐orthogonal multiple access: analysis using compute‐and‐forward cooperative relaying in 5G networks

With the increasing demand for high-speed mobile transmissions for 5G networks, the cooperative relay-aided non-orthogonal multiple access (CR-NOMA) has been highly considered. An efficient and reliable CR-NOMA not only depends on the network mechanism but on the network coding strategy at the relay. Even though conventional strategies have broadly been studied, they suffer from noise accumulation and interference. Lately, the compute-and-forward (CpF) strategy has been identified as a potential technique to mitigate interference and enhance outage probability. In this study, the authors present a mathematical formulation to examine the performance of CpF on downlink CR-NOMA. In the proposed formulation, a two-stage downlink cooperative relay network is considered to obtain analytical closed-form expressions of outage probability and bit error rate. The outage probabilities and bit error rates of existing relaying strategies are compared regarding the network model. The theoretical analysis shows that CpF requires half the number of relays desirable in amplify-and-forward and decode-and-forward strategies to achieve a proportionate outage probability in CR-NOMA. Finally, we present results to show that at a lower signal-to-noise ratio, the integration of CpF and NOMA enhances error performance irrespective of the number of users.

FiVH: A solution of inter-V-Cell handover decision for connected vehicles in ultra-dense 5G networks

The Fifth Generation (5G) cellular network requires new solutions to new network requirements, for example, support for high-speed mobility. This paper presents a handover decision solution for connected vehicles to 5G Ultra-Dense Networks (5G-UDN). Its main goal is to treat high vehicular mobility and provide performance gains in handover for vehicles, since the densification of the cellular network causes, despite the expected capacity gain, difficulties in the cells selection, a greater number of failed and unnecessary handovers (ping-pong effect), longer delays and energy consumption, and high packet losses. The solution is based on Virtual Cells (V-Cells). The selection of the best cells is made based on complex network metrics to compose a V-Cell, as well as other criteria such as signal strength, distance, and speed. The solution relies on the Software-Defined Network (SDN) controller which has centralized network information. Simulations were conducted in Network Simulator, ns-3. The results show that the solution is effective in the treatment of vehicle handover.

A Two-Tier Collection and Processing Scheme for Fog-Based Mobile Crowdsensing in the Internet of Vehicles

In view of the rapid development of the Internet of Vehicles (IoV) and wireless communication technology, intelligent transportation systems play an important role in improving urban road safety, promoting the behavioral interaction between users and networks, improving the service quality, and controlling the network cost. Based on the universality and real-time nature of the IoV, data collectors can cooperate with users to sense and collect relevant data within the driving range of vehicles. To achieve this goal, this article proposes a two-tier sensing scheme around the optimization of the sensing mechanism and data processing. In the routing layer, we build a weighted graph model based on vehicle fog, and we propose a new routing strategy to maximize each vehicle’s utilization. We consider that the sensing information collected by multiple vehicles could be repetitive, which would lead to many unnecessary communication flows in the network. Therefore, in the data processing layer, we consider resource consumption in the whole fog, assign different tasks to the sensing vehicles, and filter similar information on the relay nodes of the routing paths to reduce the waste of resources in IoV. Finally, we compare and analyze our two-tier scheme with related approaches, and the results show that our scheme has higher link utilization and lower resource consumption for a high-speed mobile network environment in IoV.

Analysis of the Impact of 5G Network Technology on Promoting the Construction of Media Convergence Center

In the age of high-speed mobile Internet, the construction of media convergence center will face more fierce competition in market as the in-depth promotion of 5G networks and the application of 5G products and technologies. In face of a new round of technological innovation, the program production and broadcasting, data transmission and processing in media convergence center will be supported by more advanced technologies. The 5G network technology will bring unprecedented transformation and development opportunities for the construction of the media center.

Analysis of Effective Routing Protocols for Flying Ad-Hoc Networks

Recently, the flying ad-hoc network (FANETs) is a popular networking technology used to create a wireless network through unmanned aerial vehicles (UAVs). In this network, the UAV nodes work as intermediate nodes that communicate with each other to transmit data packets over the network, in the absence of fixed an infrastructure. Due to high mobility degree of UAV nodes, network formation and deformation among the UAVs are very frequent. Therefore, effective routing is a more challenging issue in FANETs. This paper presents performance evaluations and comparisons of the popular topology-based routing protocol namely AODV and position-based routing protocol, namely LAR for high speed mobility as well as a verity of the density of UAV nodes in the FANETs environment through NS-2 simulator. The extensive simulation results have shown that LAR gives better performance than AODV significantly in terms of the packet delivery ratio, normalized routing overhead, end-to-end delay, and average throughput, which make it a more effective routing protocol for the highly dynamic nature of FANETs.

G2A Communication Channel Modeling and Characterization Using Confocal Prolates

Characterization of radio environment is an important field of research that helps to analyze the limiting features of the propagation environment and leads to develop a realistic channel model. This paper proposes an appropriate multipath channel model for various ground-to-air (G2A) communication scenarios. An intensive review of the existing literature on A2G/G2A channel models is presented along with a critical analysis with appropriate comments wherever needed. It is observed that most of the research literature supposedly model G2A channels interchangeably in the same manner as that of land mobile communication links. G2A communications systems are generally equipped with directional antennas for dedicated coverage to flying aircrafts that benefits in increasing range and signal strength while restraining interfering signals coming through scattering objects around ground station (G). This research analyzes G2A multipath channel and thus proposes a geometrically-based physical G2A multipath channel model. The proposed channel model clearly justifies the existence of multipath environment in G2A communication due to the existence of aircrafts in the vicinity of the intended aircraft. This model is based on a three-dimensional confocal prolate spheroids and uses the principle of single-bounce multipath geometry. Moreover, the model gives an insight to analyze multipath multiuser G2A communication in wide-beam and narrow-beam communication link scenarios. This model is equally applicable to the networks of passenger aircrafts, flocks of jet fighters and mesh of UAV drones. This model can be used to analyze the performance of high data-rate communication links with high mobile speeds over sparsely distributed multipath channels.

Optimizing TCP Loss Recovery Performance Over Mobile Data Networks

Recent advances in high-speed mobile networks have revealed new bottlenecks in ubiquitous TCP protocol deployed in the Internet. In addition to differentiating non-congestive loss from congestive loss, our experiments revealed two significant performance bottlenecks during the loss recovery phase: flow control bottleneck and application stall, resulting in degradation in QoS performance. To tackle these two problems, we first develop a novel opportunistic retransmission algorithm to eliminate the flow control bottleneck, which enables TCP sender to transmit new packets even if receiver's receiving window is exhausted. Second, application stall can be significantly alleviated by carefully monitoring and tuning the TCP sending buffer growth mechanism. We implemented and modularized the proposed algorithms in the Linux kernel thus they can plug-and-play with the existing TCP loss recovery algorithms easily. We evaluated our proposed algorithms over emulated and real experiments and showed that, compared to existing TCP loss recovery algorithms, the proposed optimization algorithms improve the bandwidth efficiency by up to 133 percent and completely mitigate RTT spikes, i.e., over 50 percent RTT reduction, over the loss recovery phase.

Design of an Energy Efficient Cluster based Localization Algorithm (EECBLA) for Underwater Wireless Sensor Networks

In underwater Wireless Sensor Networks (UWSN) the node mobility is higher as the nodes drift with the water so identifying the exact location of the nodes is a challenging task. Terrestrial WSN use Global Positioning System (GPS) to locate the nodes, but the same cannot be applied for UWSN as they do not propagate under water. Underwater uses acoustic channel for communication which suffers from low bandwidth, high propagation delay, high bit error rate, high node mobility and variable sound speed which makes localization a challenging task. Hence there is an evolving requirement for energy efficient localization algorithm. To overcome these problems we propose an Energy Efficient Cluster Based Localization Algorithm (EECBLA) to minimize the energy utilization and identify an accurate location of the sensor nodes. EECBLA is a cluster based localization protocol where the GPS enabled high power anchor nodes are utilized to estimate the location of the un localized sensor nodes. To improve the localization accuracy it is necessary to improve the network connectivity. Network connectivity can be improved by increasing the lifetime of the sensor nodes. EECBLA proposes an energy efficient localization scheme where the node operates in active and sleep mode to efficiently utilize the available energy. In this research work we take a sample example and demonstrate how the location is estimated through TOA and Euclidean distance. Accuracy of TOA is measured as 8.36, 4.76, 13.21, 14.85, 16.26 and 3.60. The average estimated localization error of EECBLA is around 4m to 6m. EECBLA localization error is compared with other localization algorithms like 3DUL whose average localization error is 5m to 10m, SDMA whose average localization error is around 24% and localization error of Hybrid RSS ranges from 4.69m to 15.85m. When compared with these methodologies there is a decrease in localization error by 3%, and the increase in accuracy by 5% in EECBLA protocol.

Reliable Mobile Edge Service Offloading Based on P2P Distributed Networks

Intelligent vehicles and their applications increasingly demand high computing power and low task delays, which poses significant challenges for providing reliable and efficient vehicle services. Mobile edge computing (MEC) is a new model that reduces the completion time of tasks and improves vehicle service by performing computation offloading near the moving vehicles. Considering the high-speed mobility of the vehicles and the unstable connection of the wireless cellular network, symmetric and geographically distributed edge servers are regarded as peers in a peer-to-peer (P2P) network, and a P2P-based vehicle edge offloading model is proposed in this paper to determine the optimal offloading server for the vehicle and the offloading ratio of tasks to achieve the goal of minimizing execution time. Because the edge computing infrastructure is deployed at the edge of the network, the data in the edge nodes are easily damaged or lost. Therefore, a P2P-based edge node fault tolerance mechanism is proposed to improve the reliability and fault tolerance of the system. The feasibility and effectiveness of our proposed system have been verified through simulation experiments, which greatly reduces the task completion delay.

Electrochemical Detection of Analytes in Fluids

A sufficient intake of nutrients is essential to remain healthy and hence few accurate methods of analysis for these nutritional values in pharmaceutical, fruits, milk, energy drinks, etc. are required. A wide variety of analytical techniques, such as Thermogravimetry, Spectrophotometry, High performance Liquid Chromatography (HPLC), HPLC coupled with Mass Spectroscopy, Colorimetric, Flow Injection Chemiluminescence, Fluorimetric and Electrophoresis, etc. have been reported for the quantification of such nutrients. However, some of these methods are inappropriate for standard analysis as these techniques employed under these methods are complicated analytical processes, time-consuming and involve expensive instrumentation. Therefore, it is essential to develop a simple method to monitor the nutritional values over a wide range. Among various analytical methods, electroanalytical technique is a potential alternative due to fast, simple, and low-cost detection capabilities, making them ideal for applications in the field of pharmacy, food, and agriculture. Also, due to the possibility of miniaturization, this analytical technique gained much attraction. There has been a consistent effort towards the development of novel sensing strategies with specific attention to enhance specificity, sensitivity, and response time. In recent years, electrochemical methods are applied widely to detect and determine a variety of biological compounds, organic molecules and inorganic ions. Among various electroanalytical methods, cyclic voltammetry, differential pulse voltammetry, chronoamperometry, chronocoulometry, linear sweep voltammetry, square wave voltammetry and adsorptive stripping voltammetry are commonly employed for the detection of analytes. There are few selected nanomaterials that are being used as base materials in emerging technologies for possessing exceptional potential. Among such materials, tin oxide (SnO2) is a material with exciting sensing properties such as high sensitivity, good chemical stability, high electron mobility, fast response, and good recovery speed. It is a key functional material that has been used extensively in transparent conductors, transistors, optoelectronic devices and electrochemical modifiers on electrodes. Electrochemical analysis using SnO2 nanomaterial has been used for the qualitative and quantitative determination of amount of electro active analytes. This method is reported to be highly accurate, reliable and cheap.During the last few years, we began to focus on synthesizing and developing SnO2 nanomaterials for the detection of different analytes in fluids. My team is currently working for the detection of different analytes like Folic acid, Riboflavin and Vitamin B12, etc. in fluids and pharmaceutical samples. It is observed that all these analytes can be detected using certain modifications in sensing (SnO2 nanomaterials) electrodes. The sensing characteristics of SnO2 can further be improved by chemical doping with appropriate elements. The advantage of this method is that the detection is possible multiple times using same sensing electrode. As per our experience, SnO2 has great potential to become an economical sensing electrode and can be synthesized on any conducting substrates. This talk will discuss examples of ongoing research work on different SnO2 based sensors. Figure 1

SnO2 nanowires for Electrochemical Detection of Riboflavin

Introduction There are few selected nanomaterials that are being used as base materials in emerging technologies for possessing exceptional potential. Among such materials, tin oxide (SnO2) is a material with exciting sensing properties such as high sensitivity, good chemical stability, high electron mobility, fast response, and good recovery speed [1]. Electrochemical analysis using SnO2 nanomaterial has been used for the qualitative and quantitative determination of amount of electro active analytes. This method is reported to be highly accurate, reliable and cheap. Several characterization techniques are used to investigate the electrochemical response like Cyclic voltammetry (CV), Differential Pulse Voltammetry (DPV), Square Wave Voltammetry (SWV) or Pulsed Amperiometry (PA) [2]. SnO2 nanowires are hereby reported for the detection of Riboflavin (RF). It is observed that the synthesized nanowires can detect the analyte efficiently. Method SnO2 nanowires were synthesized by template-directed electrodeposition. Copper foil was used as the substrate. The Sn nanowires were electrodeposited into the nanoholes of the polycarbonate membranes by a three-electrode system in a solution containing 0.05 M SnCl2.2H2O and HCl at room temperature. The electrochemical synthesis was performed on a CHI660 electrochemical Workstation. The electrodeposition was performed at -0.7 V (vs saturated Ag/AgCl), with platinum serving as the counter electrode. After SnO2 nanowires were electrodeposited into track etch polycarbonate membranes, the assembly system was annealed in the air at 85oC to form an ordered SnO2 nanowire array. Ag/AgCl as a reference electrode and gold as an auxillary electrode were used to set up the modifications in detection technique. CV, DPV and EIS techniques were used for the successful detection of RF. Moreover, for measuring the pH values, a pH meter with a combined electrode (glass-reference electrode) was used. All potentials are measured against the Ag/AgCl reference electrode at room temperature. Results and Conclusions Field-emission scanning electron microscopy (FE-SEM) is used to characterize the morphologies of the as-prepared products. To demonstrate the chemical composition, EDS analysis was performed. The crystal structure of the as-prepared samples is determined by X-ray diffraction (XRD) with Cu Kα radiation. All these results showed that the nanowires are successfully synthesized in their pure form. Electrochemical studies were carried out by CV and DPV studies. EIS technique also verified about the successful determination of analytes. The developed sensor exhibits good stability, reproducibility and efficiency. Moreover, its practical application was also checked in pharmaceutical samples by the recovery test. For RF content in pharmaceutical samples in the range from 52-150 μM, the developed sensor retains its linearity which indicates that the fabricated sensor not only works well in 0-13 μM range but beyond that range also. Compared with all other existing electrodes reported in the literature, the reported work not only showed remarkably lower detection limit but also the cheapest electrode ever synthesized.

FBIA: A Fog-Based Identity Authentication Scheme for Privacy Preservation in Internet of Vehicles

In recent years, the Internet of vehicles (IoV) has become an indispensable part of wireless communication. To protect users' privacy and communication security, an increasing number of scholars have focused on studying the safety of the IoV. However, due to the characteristics of the IoV, the problem of privacy protection and communication security has not been sufficiently studied and remains open in the IoV; thus, it is worthwhile for us to further explore and study the precise and dynamic safety certification in high-speed driving environments. In our study, we divide the IoV into several fogs to reduce the burden on the traffic control center and propose a new security authentication scheme with the vehicle's identity based on the security elliptic curve. The fog-based identity authentication (FBIA) scheme consists of two layers: the security authentication layer for vehicles outside the fog and the security monitoring layer for the rest of the vehicles. We propose two-way authentication based on the vehicle's identity in the security authentication layer and a deep learning scheme in the security monitoring layer to conduct real-time security in the IoV. Finally, we compare and analyze our FBIA scheme with related approaches, and the results show that the FBIA scheme has higher authentication accuracy and better adaptability to a high-speed mobile network environment in the IoV.

Experiences With Developing and Using Vital Sign Telemonitoring to Support Mobile Nursing in Rural Regions: Feasibility and Usability Study.

BackgroundModern information and communication technology has the potential to support mobile care in rural regions such as the Alpine region, which is characterized by long distances or even physically unreachable areas.ObjectiveThis study investigated the potential of supporting mobile nursing organizations in rural regions with the use of mobile telemonitoring systems in a case study setting.MethodsAs a subproject of the European Union–funded project INTESI, the VITAl parameter MOnitoring (VITAMO) project gathered stakeholders’ requirements for telemonitoring support of mobile care in rural regions and then developed and implemented a prototype system that was used for a 3-month test period with a local nursing organization in Austria. Log analysis, surveys, and interviews were used to evaluate the system according to the Technology Acceptance Model. The focus was technology assessment and user satisfaction of both patients and nurses.ResultsParticipants were provided Bluetooth devices to measure blood pressure, body weight, and blood glucose and to track activity. They also received a tablet with a mobile internet connection to see the results. The nurses were able to access the results remotely. Regularly executed speed tests and log analysis demonstrated the availability of high-speed mobile internet in the rural test region. Log analysis, surveys, and interviews revealed the suitability of the technology environment and showed that the system was easy to use and potentially useful. The perceived usefulness for supporting mobile care was rated meaningfully low, and the frequency of nurses using the tool declined continuously over the field test period. Further group discussions investigated this issue.ConclusionsWhile the technology environment with mobile internet, Bluetooth devices, and smart vital sign monitoring devices was adequate and suitable to support mobile nursing in rural regions, the potential benefit for the nursing organization could not be confirmed. Further analysis revealed that operational care processes did not follow a well-defined care strategy. Technology has the potential to leverage the available environment for developing meaningful solutions. These experiences could contribute to further investigations that need to identify and analyze existing mobile care processes at an organizational level.

An Effective Privacy-Aware Sybil Attack Detection Scheme for Secure Communication in Vehicular Ad Hoc Network

Nowadays, VANET plays significant role to enhance safety, mobility and convenience applications in intelligent transportation system. However, security in such systems still remains a big challenge because of its large coverage, wireless communication and high-speed mobility of the nodes. Sybil attack as a serious security threat creates new identities for neighboring vehicles or steals vehicles identities for the attacker. The purposes of creating invalid identities are network disruption, misleading neighbor vehicles for traffic jams or fatal and tragic accidents, opening the road, disruption in voting based systems, and violating traffic safety briefly. In the present study, a privacy-aware Sybil attack detection (PASAD) scheme is proposed to solve two conflicting goals: to preserve the privacy and to detect the Sybil attack in the vehicle to vehicle (V2V) and vehicle to roadside unit (V2R) communications. The proposed scheme is based on a safe physical authentication and Boneh-Shacham (BS) short group signature scheme. The theatrical analyzes show that this scheme ensures the security requirements like correctness, privacy, unforgeability, traceability, and Sybil attack detection in exchanges of warning messages. Extensive simulations and analysis demonstrate the efficiency and effectiveness of the proposed scheme in vehicular networks.