Mobile Radio Environment Research Articles

A Noval and Efficient Three-Party Identity Authentication and Key Negotiation Protocol Based on Elliptic Curve Cryptography in VANETs

In the process of vehicles transitioning from conventional means of transportation to mobile computing platforms, ensuring secure communication and data exchange is of paramount importance. Consequently, identity authentication has emerged as a crucial security measure. Specifically, effective authentication is required prior to the communication between the On-Board Unit (OBU) and Roadside Unit (RSU). To address vehicle identity authentication challenges in the Internet of Vehicles (VANETs), this paper proposes a three-party identity authentication and key agreement protocol based on elliptic curve public key cryptography. Considering issues such as vehicle impersonation attacks, RSU impersonation attacks, and vehicle privacy breaches in existing schemes within wireless mobile environments, this protocol introduces a trusted registry center that successfully enables mutual authentication between OBU and RSU. The proposed protocol not only enhances the VANETs system’s ability to withstand security threats but also improves the credibility and efficiency of the authentication process.

Brand relationships in wireless mobile environments: The mediating role of apps

AbstractBrands use branded mobile apps to interact with users and to develop brand relationships in wireless mobile environments. These apps collect data about users and app usage, which are potentially helpful for brand relationship research. We aim to contribute to understanding the user–brand relationship (UBR) measurement mediated by branded apps, an area with very limited research, with a focus on leveraging these apps as a gauging context to measure the UBR strength. We propose a data‐driven model to measure the UBR strength that combines metrics computed by using branded app data with close interpersonal relationship indicators. We conducted a computer simulation to test the proposed model. Our findings show that app usage time is the metric that most affects UBR strength measurement. The results suggest that time is essential for developing brand relationships in wireless mobile environments, much like in interpersonal relationships. The proposed model can be supplemented with other metrics to study new attributes associated with the UBR that might emerge in these environments.

RANCE: A Randomly Centralized and On-Demand Clustering Protocol for Mobile Ad Hoc Networks

LEACH-like clustering protocols focus mainly on the low-power, low-rate, and low-wakeup network applications, and work in a multiround clustering strategy that causes frequent handovers of cluster heads (CHs), thus less support for real-time services that require stable cluster topologies. Besides, these protocols are faced with respective drawbacks, such as suboptimality of selected heads, costly node-base station (BS) energy overheads, lack of runtime cluster maintenance, etc. This article proposes RANCE, a randomly centralized and on-demand clustering protocol, aiming at prolonging nodes’ clustered time to support internodes collaboration while being energy efficient in mobile ad hoc networks. First, RANCE designs a randomly centralized CH selection mechanism in which every node in the local wireless network is eligible to initiate the centralized CH selection, so that the self-organizing characteristics of mobile ad hoc nodes can be utilized for head selection optimization. Second, taking into account the wireless volatility caused by changes of topology, obstacles, signal strength, etc., the fine-grained cluster relationships maintenance is provided by means of multilevel aliveness and adaptive bidirectional heartbeat packets. Third, RANCE works in an event-driven and on-demand manner instead of a time-triggered manner in LEACH-like protocols, to reduce the impact on continuous services caused by frequent CH handovers among all nodes. Simulation results show that RANCE provides longer clustered time (over 99% of nodes’ lifetime in networks more than 100 nodes) and good clustering scalability with high consistency at minimum energy cost, and exhibits good potentials in mobile wireless environments that are infrastructureless/poor for continuous missions.

IS-DT: A New Feature Selection Method for Determining the Important Features in Programmatic Buying

Traditional data-driven feature selection techniques for extracting important attributes are often based on the assumption of maximizing the overall classification accuracy. However, the selected attributes are not always meaningful for practical problems. So, we need additional confirmation from the experts in the domain knowledge to determine whether these extracted features are meaningful knowledge. Moreover, due to advances in mobile devices and wireless environments, programmatic buying (PB) has become one of the critical consumer behaviors in e-commerce. However, it is extremely difficult for PB service providers to build customers’ loyalty, since PB customers require a high level of service quality and can quickly shift the purchases from one website to another. Previous studies developed various dimensions/models to measure the service quality of PB; nevertheless, they did not identify the key factors for increasing customers’ loyalty and satisfaction. Consequently, this study used an importance–satisfaction (IS) model as domain knowledge and proposed a new IS-DT feature selection method. This new IS-DT method combined the IS model and the decision tree (DT) algorithm to extract useful service quality factors for enhancing customer satisfaction and loyalty in PB. An actual case was also provided to illustrate the effectiveness of our proposed method. The results showed that for increasing customer satisfaction, the highest impact factors included “problem solving”, “punctuality”, “valence”, and “ease of use”; for building customer loyalty, the most important factors were “expertise”, “problem solving”, “information”, “single column”, “voice guidance”, “QR code”, “situation”, “tangibles”, “assurance”, “entertainment”, and “safety”. Our IS-DT method can effectively determine important service quality factors in programmatic buying.

Context-based caching in mobile information-centric networks

Wireless networking is expected to sustain the direct interaction between personal users’ devices, and to provide connectivity on large-scale resource-constrained devices. However, conventional networking protocols fail in large scale mobile wireless environments, due to node mobility, dynamic topologies, and intermittent connectivity. Information-Centric Networking (ICN) has been considered the most promising candidate to overcome the drawbacks of host-centric architectures where Named Data Networking (NDN) is one of the well-known and studied architectures within the ICN paradigm.The main objective of this work is to improve both content availability and network performance in mobile environments regarding the ICN paradigm. This is provided through a context-based approach for the caching admission policy providing in-network caching and content replication, facilitating the efficient and timely delivery of information. Content popularity, freshness, proximity, source mobility type and network density are some of the metrics considered in the caching decision. We conducted a comparative study between our proposal and the NDN caching strategy by using two different datasets with real mobility and connectivity traces, addressing intermittent communication. According to our results, we observed that using a multi-criteria context-based cache admission policy improves cache hits, cache evictions, and request satisfaction ratios in mobile environments, thus improving content delivery and network efficiency.

Insights from the Experimentation of Named Data Networks in Mobile Wireless Environments

The Information-Centric Network (ICN) paradigm has been touted as one of the candidates for the Internet of the future, where the Named Data Network (NDN) architecture is the one leading the way. Despite the large amount of works published in the literature targeting new implementations of such architecture, covering different network topologies and use cases, there are few NDN implementations in real networks. Moreover, most of these real-world NDN implementations, especially those addressing wireless and wired communication channels, are at a small scale, in laboratory environments. In this work, we evaluate the performance of an NDN-based implementation in a mobile wireless network, as part of a smart city infrastructure, making use of multiple wireless interfaces. We start by showing how we have implemented the NDN stack in current network nodes of the smart city infrastructure, following a hybrid solution where both TCP/IP and NDN paradigms can coexist. The implementation is evaluated in three scenarios, targeting different situations: mobility, the simultaneous use of different wireless interfaces and the network characteristics. The results show that our implementation works properly and insights about the correct NDN parameterization are derived.

Consumer Mobility Awareness in Named Data Networks

Mobile data traffic has increased significantly due to the evolution of wireless communication technologies. The Information Centric Network paradigm is considered as an alternative to bypass the restrictions imposed by the traditional IP networks, especially those related with the mobility of its users. Despite the potential advantages of this paradigm regarding mobile wireless environments, several research challenges remain unaddressed, more specifically the ones related with the communication damage caused by handovers. This work presents a Named Data Network (NDN) based solution that supports Consumer mobility. The proposed scheme addresses a mobility manager entity that monitors and anticipates trajectories, while compelling the infrastructure to adjust to the new paths. This process results in an efficient way to manage the Consumers’ mobility, and therefore, in a better quality of service to its users. The implementation and evaluation of the proposed solution uses the ndnSIM, through functional and non-functional scenarios, and with real traces of urban vehicular mobility and connectivity. The results show that the proposed solution is superior to the native NDN workflow with respect to content delivery ratio and number of timeouts.

High Efficiency Beam Alignment Based on Multi-Modal Beam Patterns for Massive MIMO Antenna Systems

Multiple-input multiple-output (MIMO) is considered as the key technology for 5G wireless communications networks. In the millimeter-wave (mmWave) frequency bands, directional beamforming is essential to the establishment of an efficient radio link for signal transmission. However, in wireless mobile environments, the effective beam direction is generally unavailable in the initial access phase. Hence, beam alignment (BA) is crucial for link establishment in initial access. In this work, we propose an efficient BA technique, referred to as the multi-modal pattern BA scheme, to improve the performance and efficiency of initial access in massive MIMO systems. Unlike the conventional sequential search scheme using single-modal patterns, the transmission of synchronization signals in the proposed scheme is based on the use of multi-modal patterns, each of which specifies multiple main lobes with distinguishable directions. Incomparison with the conventional scheme, our scheme can greatly enhance the achieved angular resolution after BA under the use of a fixed number of synchronization signals. As a result, the signal-to-noise ratio (SNR) of the established link is significantly improved. By contrast, if the same angular resolution is desired, the proposed scheme can greatly reduce the number of required synchronization signals to conserve the radio resources, including transmission power and bandwidth, and to decrease the searching delay in the BA procedure. In addition, considering multi-modal pattern construction for the transmission using a single radio-frequency (RF) chain, we propose an effective approach to generate the desired beamforming vectors fulfilling the essential constant amplitude constraint.

Joint beamforming and user association with reduced CSI signaling in mobile environments: A Deep Q-learning approach

Heterogeneous Cloud Radio Access Network (H-CRAN) is considered as a cost-efficient network solution to meet 5G data traffic requirements. In this paper, we consider the problem of beamforming and user clustering (user-to-Remote Radio Head (RRH) association) in the downlink of a H-CRAN where users have heterogeneous mobility profiles. Given the rapidly time-varying nature of the mobile wireless environment, it is challenging to offer an optimal beamforming and user association performance during a long-term allocation process without incurring large Channel State Information (CSI) and signaling overheads. For that purpose, we proposed in Ha et al. (2019) an Adaptive Beamforming and User Clustering (ABUC) algorithm which resolves the joint beamforming and user clustering problem when considering CSI cost and imperfectness under user mobility assumptions. In this paper, we design a deep reinforcement-learning framework which enables the proposed ABUC algorithm to select on-the-fly its best feedback scheduling parameters, namely the period and type of CSI feedback, given each user mobility profile. The proposed ABUC-DQL approach can overcome the scalability limitation of the Q-learning approach (Ha et al., 2019) and better handle the problem when formulated using a POMDP (Partially Observable Markov Decision Process) model. The simulation results show that the convergence time is mainly impacted by the number of users in the network, and the online-learning ability of the framework can quickly adapt to the changes of users mobility.

Improving Data Services of Mobile Cloud Storage with Support for Large Data Objects using OpenStack Swift

Providing data services support for large file upload and download is increasingly vital for mobile cloud storage. There is an increase in mobile users whose data access trends show more access and large file sharing. It is a challenging task for Mobile Application Developers to handle upload and retrieve large files to/from a mobile app because of difficulties with latency, bandwidth, speed, errors, and disruptions to service in a wireless mobile environment. Some scenarios require these large files to be used offline, sometimes to be updated by a single user, and sometimes be shared among all other users. The Wireless mobile environment must consider mobile user’s constraints, such as frequent disconnections and low bandwidth, which affect the ability to handle data and transactions management. The primary objective of this study is to propose a cloud-based Mobile Sync service (sometimes referred as Mobile backend as a Service) with OpenStack Swift object storage to manage large objects efficiently using two main techniques of segmentation and object chunking with compression in a mobile cloud environment. This work further contributed to a prototype implementation of the proposed framework and provides Application Programming Interface (API) consisting of Create, Read, and Delete queries and chunking operations and a lightweight sync protocol that can manage large file synchronization and access. The experimental findings with object-chunking tested size settings show that the proposed Mobile Sync framework can accommodate large files ranging from 100MB to 1GB and provides a decrease in upload/download synchronization times of 63.203% / 92.987%percent as compared to other frameworks.

Clustering-cum-Handover Management Scheme for improved Internet access in high-density mobile wireless environments

The accessibility of ubiquitous communication services from various wireless technologies has become essential in the current Internet of everything (IoE) era. It is crucial for mobile users residing in densely populated areas to get the provision of uninterrupted connectivity and seamless services. To this end, this paper provides a mechanism for uninterrupted connectivity to a maximum number of users with the available resources. We propose a master/slave model in a 4G-Wi-Fi integrated network. Our novel Clustering-cum-Handover Management Scheme (CHMS) for dynamic cluster management together with the handover management in high density mobile wireless environment dispenses the unrestricted movement without connectivity loss and quality sacrifice. The dynamically configured clustering protocol of CHMS provides reduced cluster formation overhead and balances the load between cluster heads. To make smart selections, a distance-based energy-efficient clustering scheme is proposed for calculating the chances of a mobile device to become a cluster head. The seamless handover mechanism of CHMS manages the mobility of both the cluster head and cluster member while considering the limited energy of devices. It also achieves high network throughput and reduced end-to-end delay during handovers. Furthermore, our evaluation shows that CHMS provides application-specific quality of service even in highly dense wireless environments.

Simulation of natural disasters and managing rescue operations via geospatial crowdsourcing services in tensor space

Natural disasters have always been difficult to manage because of their spatio-temporal scale. Although the use of GIS and RS has made this process somewhat simpler, there are still serious challenges in managing and smart allocating human resources, increasing operational power and cost savings, continuous monitoring, and ensuring the effectiveness of the relief activities. The development of VGI and the studies of big data have provided the prerequisite for the introduction of the crowdsourcing service into the GIS. In this research, we tried to solve some of the problems and challenges of crisis management by relying on the characteristics of the crowdsourcing service and its integration with the GIS. Dividing complex emergency processes into atomic crowdsourcing services in a wireless mobile environment is regarded as an appropriate solution. Proposed atomic crowdsourcing services include an informative, content, and confirmative segment. Composing such services can manage sophisticated crisis fields. But, the use of services necessitates a robust and operational framework. This framework must also be capable of simulating the environment in addition to executing, managing, and communicating with the environment. However, current crisis management frameworks cannot cover all these issues at the same time. The present study aims to design a crisis crowdsourcing mathematical framework, which has been constructed upon vector space elements, tensors, and geometrical products. Vectors simulate crisis environment for main objects in a multi-dimensional space. In addition, operations are coincided with possible actions among crisis objects. Framework introduces tools to compose and arrange services in optimum mode to conquer complex aiding process. Since low-speed and high processing load are among the fundamental problems of existing software frameworks, the use of tensors and matrices in frameworks increase the speed and decrease the processing load due to cumulative integrated computing. Further, it offers a mathematical intelligible documentation method, which is able to record the processing details as well as the object status in space. On the other hand, although tensors are widely used in other fields of engineering, there is little record of their use in GIS or crisis management. Thus, with the designed framework, it is possible to use the experiences gained from other disciplines. Different scenarios have confirmed the accuracy and efficiency of the framework in deploying potential of crowds. It offers an environment to easily incorporate people in a wireless mobile application, to tackle emergency process. Indeed, rather than the social aspects of research in providing a new IT-based methodology for employing crowd’s ability, this research has implemented a special math framework for managing new proposed crowdsourcing services that is easily implemented through a mobile GIS system in a wireless network.

A Simple Video-Based Technique for Measuring Latency in Virtual Reality or Teleoperation.

Designers of virtual reality (VR) systems are aware of the need to minimize delays between the user's tracked physical actions and the consequent displayed actions in the virtual environment. Such delays, also referred to as end-to-end latency, are known to degrade user performance and even cause simulator sickness. Though a wide variety of hardware and software design strategies have been used to reduce delays, techniques for measuring and minimizing latency continue to be needed since transmission and switching delays are likely to continue to introduce new sources of latency, especially in wireless mobile environments. This article describes a convenient low-cost technique for measuring end-to-end latencies using a human evaluator and an ordinary consumer camera (e.g., cell phone camera). Since the technique does not depend upon the use of specialized hardware and software, it differs from other methods in that it can easily be used to measure latencies of systems in the specific hardware and software configuration and the relevant performance environments. The achievable measurement accuracy was assessed in an experimental trial. Results indicate a measurement uncertainty below 10 ms. Some refinements to the technique are discussed, which may further reduce the measurement uncertainty to approximately 1 ms.

Enhancing Throughput of Optimum Channel in Ofdm Based Full Duplex Communication

The efficient use of radio facilities in cellular networks is essential and being widely studied. This letter sees a cellular relay system where various user couples perform trans-directional interaction via various relays relying on Orthogonal Frequency-Division Multiplexing (OFDM) communication.. Joint implementation of route and transmit allocation, along with subcarrier coupling, subcarrier distribution as well as relay choice, for complete output redistribution is identified as a combination estimation issue.. Using a graph conceptual strategy, we can efficiently fix the problem in exponential time by converting it into a Optimum Adjusted Bipartite Tracking (MWBM) issue. Simulation experiments are conducted to assess the complete throughput of the network versus transmitting energy per node and the number of relay nodes. Carrier frequency offset causes a number of impairments including attenuation and rotation of each of the subcarriers and intercarrier interference (ICI) between carrier frequency offset causes a number of impairments including attenuation and rotation of each of the subcarriers and intercarrier interference (ICI) between subcarriers. In the mobile radio environment, the relative movement between transmitter and receiver causes doppler frequency shifts, in addition, the carriers can never be perfectly synchronized. These random frequency errors in OFDM system distort orthogonality between subcarriers and thus intercarrier interference (ICI) occurs. A Number of methods have been developed to reduce this sensitivity to frequency offset

Investigation and pathloss modeling of fourth generation long term evolution network along major highways in Lagos Nigeria

This study presents propagation measurements of fourth generation long term evolution (4G LTE) network using Huawei Technologies drive test equipment. Measurements were taken from three transmitting evolved node base stations (eNodeBs) located along three major routes in Lagos Nigeria, at an operating frequency of 1800MHz.Measured pathloss was comparatively analyzed with respect to predictions made by free space, flat earth, Okumura-Hata, Walfisch-Ikegami, Ericsson, ECC-33, and Lee models. Results showed that the free space, flat earth, Walfisch-Ikegami, ECC-33, Ericsson, and Lee models over predict the path loss along the tested routes with root mean square errors (RMSEs) relatively higher than the specified range. The Okumura-Hata model showed the best performance with RMSEs of 7.42dB, 7.63dB and 9.64dB along the investigated routes 1, 2, and 3, respectively. This model was modified using the least square method in order to enhance its signal prediction accuracy. The modified Okumura-Hata model predicted the path loss along routes 1, 2, and 3, with RMSEs of 5.20dB, 4.89dB and 8.78dB, respectively. Overall, the modified Okumura-Hata model showed lower RMSEs closer to zero which are acceptable. This model could find very useful applications in the area of quality signal prediction and pathloss modeling for related wireless mobile environments. Keywords: Propagation measurements, 4G LTE network; measured pathloss; drive test; eNodeBs; Lagos highways; Okumura-Hata model; root mean square error; least square method

Secure Key Agreement and Key Protection for Mobile Device User Authentication

As mobile devices ownership becomes more prevalent (e.g., a user owns multiple mobile devices), the capability to offer secure and user friendly authentication becomes increasingly important. A large number of identity-based user authentication mechanisms for the wireless mobile environment have been proposed. However, they are not generally designed for situations where a user’s private key and some other sensitive data can be exposed if his/her mobile device is remotely or physically controlled by an attacker. Threshold secret sharing is one of the solutions to this problem, but it is limited in the requirement that there should exist an honest third-party to hold the complete key after the secret reconstruction process. Therefore, in this paper, we consider the special case that only two devices (i.e., no honest party) at the user’s side jointly perform user authentication with a server, and neither device can successfully complete the authentication process alone. Moreover, the key reconstruction is not needed during authentication so that neither device can hold a complete key. We then analyze the security of the proposed protocol and show that it satisfies all known security requirements in practical applications, particularly the key exposure attack resistance. The performance analysis of the proposed protocol is also presented to demonstrate its practicality.

Performance Modeling of Delayed Offloading in Mobile Wireless Environments With Failures

Mobile devices and wireless network links are sometimes unreliable and unstable owing to user mobility in mobile wireless environments. As a result, failures may occur during the offloading process, which has a huge influence on the offloading performance. Worse still, it is challenging to make high-level offloading decisions since they closely rely on an accurate predicting model, especially when encountering with offloading failures. Unfortunately, due to the high mobility and heterogeneous network environments, such a model is currently not available to researchers and practitioners. To fill that gap, this letter develops an analytical queueing model for delayed offloading systems with intermittent connectivity. We set a deadline to detect offloading failures when taking the impatient jobs and service interruptions into account. Furthermore, for different types of mobile applications, a tradeoff analysis between energy saving and latency reducing is analyzed on the basis of an energy–response time weighted product metric. The proposed offloading model can be effectively used for describing complex and realistic offloading systems with the presence of failures.

Machine-to-Machine Content Retrieval in Wireless Networks

Machine-to-Machine (M2M) communication is a distinct capability that enables communications with anything. With the expected connection among several tens of billions of addressable mobile devices and the exchange of a huge amount of content, the Internet and mobile communication are entering a new era that inevitably faces several challenges, especially from a content dissemination perspective. It has been exposed to many limitations such as high control overhead, frequent location updates, and network congestion. To resolve such limitations, this paper proposes an efficient hierarchical routing and content retrieval mechanism, which is called Hierarchical Routing (H-Routing) for the wireless network based on Content-Centric Networking (CCN). The H-Routing is composed of a novel content discovery approach and a common service platform for generic communications and the integration of heterogeneous devices. The proposed mechanism uses CCN and Chord-like lookup in a hierarchical M2M system in the wireless mobile environment. The H-Routing mechanism reduces unnecessary flooding of content request messages, control overhead, and the waste of resources. We also implemented the proposed mechanism in the simulation environment and analyze the performance in terms of throughput, Interest packet overhead, and Interest error ratio.

Real-time-based E-health systems: design and implementation of a lightweight key management protocol for securing sensitive information of patients

Group-based systems, such as e-health systems, have been introduced since the last few decades. E-health systems can be used anytime and anywhere for patient monitoring. Wireless networks are continuously used to monitor patients’ conditions and recovery progress. The confidentiality, integrity and authenticity of patients’ health records are important to secure in such applications. Efficient key management and distribution are required to secure e-health applications in a wireless mobile environment. However, existing key management protocols cannot route e-health applications securely due to the resource-constrained architecture of the wireless mobile environment. A novel and enhanced key management scheme which aims to identify the challenges related to the security and privacy issues of patients’ sensitive information through a strong encryption management is proposed in this study. The proposed model also aims to provide a well-organised and lightweight key management mechanism. This system requires few computations of keys and offers a null rekeying mechanism to ensure forward and backward secrecies. As a result, a secure and privacy-preserving key management scheme for e-health systems, which is known as the healthcare key management (HCKM) framework and aims to decrypt the ciphertext of the same plain text with different keys, is acquired. HCKM minimises the rekeying overhead of group members and the overhead expressed in terms of the number of exchanged messages whilst achieving a sufficiently high security level. The proposed protocol also can operate on dynamic scenarios with a large number (thousands) of nodes and exhibits an excellent performance under the assumption of low rate of evictions. © 2018, IUPESM and Springer-Verlag GmbH Germany, part of Springer Nature.

Noise Model of Capacitive and Textile Capacitive Noncontact Electrodes for Bioelectric Applications.

In this paper, a comprehensive model for the electronic noise properties and frequency-dependent responses of printed circuit board (PCB)-based as well as textile noncontact capacitive electrodes is presented. For bioelectric diagnostics, noncontact capacitive electrodes provide an interesting alternative to classical galvanically coupled electrodes, since such a low-cost diagnostic system can be applied without preparation time and in mobile wireless environments. For even higher user comfort, textile capacitive electrodes are preferable. This paper provides a thorough study of the influence of the electrical components of capacitive electrodes and textile capacitive electrodes, as well as their surface area and circumferences on the resulting noise properties of the electrode by independently measuring the corresponding noise spectra. Consequently, the equivalent noise model is developed. The most important noise source is the high input bias resistance, which, in combination with the involved capacitance, results in an apparent $1/f^2$-power noise spectrum. By comparing the noise measurements with the noise model of the electrode, we conclude that the surface of the electrode contributes to an additional $1/f$ -power noise in the noise spectrum. We also found that the highest possible coupling capacitance is most favorable for low-noise behavior. Therefore, electrodes with electrically conducting fabric surfaces are investigated. Due to this, it is possible to enlarge the surface of the electrode and maintain a small distance between the body and the surface of the electrode. We show that with the use of textile capacitive electrodes, it is possible to reduce the noise characteristics considerably. Our findings in this paper provide a necessary source for further optimization of capacitive electrodes for bioelectric measurement applications.