Handover Procedure Research Articles

An Energy-Efficient Proactive Handover Scheme for Vehicular Networks Based on Passive RSU Detection

Recently, the Vehicular Network (VN) has received a lot of attention from researchers around the world. By allowing wireless communication, VNs enable information exchange among vehicles, which in turn has allowed drivers to become more aware of their surrounding road conditions. Accordingly, road safety is improved. However, due to the fast speed and frequent changes of direction of vehicles, the network topology of VNs is transient in nature. Hence, achieving efficient data dissemination/content delivery is a critical issue in the VNs-environment. In this article, we will introduce a novel passive roadside unit (RSU) detection-based proactive (PRDP) handover scenario. Consequently, the overhead of the handover process can be reduced, and the probability of successfully established connections can be improved. More precisely, by taking advantage of the Doppler effects of the received beacon signal, the passive RSU detection (PRD) scheme is derived by the maximum likelihood estimation function. Then, in combination with the extended Kalman filter (EKF), the PRDP handover protocol is designed to improve the energy efficiency of the handover procedure in the VNs-environment. We conduct intensive simulations to verify the proposed RSU detection scheme, and the experimental results further evaluate the performance of the proposed energy-efficient proactive handover protocol.

DMM-SEP: Secure and Efficient Protocol for Distributed Mobility Management Based on 5G Networks

In the 5G era, network mobility management is recognized as a very important factor for user service availability. Especially, due to fast speed and shrinking cell coverage, frequent handover is expected than before. Hence, efficient handover procedure is essential to guarantee seamless service to users. Distributed IP Mobility Management (DMM), a major mobility management solution, is a flat architecture that achieves efficiency and fault tolerance by excluding a centralized anchor and minimizing the distance between a mobile device and its serving network. However, DMM, which has no dominant security scheme specified to itself, is excessively dependent on the security of Layer 2 and is vulnerable to various threats. Especially, the existing security schemes are still venerable to redirection attacks launched by malicious Mobile Access Gateways (MAGs) or Control Mobility Database (CMD). Motivated by this, we proposed a DMM-based handover security protocol that can support privacy and defend against redirection attacks in addition to providing essential security properties such as confidentiality, integrity, mutual authentication, and key exchange. The proposed protocol was formally verified to be correct through AVISPA and BAN logic. Moreover, the comparison analysis showed that the proposed protocol is better than the previous studies and standards.

Bandwidth Distribution Algorithm of Applications in LTE-Femtocell Network

The wireless communication has become the essential of today’s Internet of Things (IoT) and mobile applications which is increasing exponentially in near future. These applications demand high data rate to speed up the communication among IoT or internet applications. The data rate requirement of individual application is different. To fulfill these demands of every application Long Term Evolution (LTE) integrated with femtocell technology is identified as suitable wireless technology. The running applications on a user equipment changes dynamically. Hence in dense deployment of femtocell and IoT devices, the bandwidth distribution to many active applications becomes more complicated. For multiple running applications per device with available bandwidth constraint, optimal bandwidth allocation to applications has become the most challenging issue. We include the bandwidth allocation to applications during handover of user equipment in LTE-femtocell network. The handover procedure needs efficient cell selection criteria for target cell selection. Hence in our research we focus on bandwidth distribution among applications by proposing “Efficient Bandwidth Distribution” (EBD) mechanism and efficient cell selection by “Dynamic Cell Selection” (DCS) mechanisms to mitigate above mentioned issues.

Location-Based Discovery and Vertical Handover in Heterogeneous Low-Power Wide-Area Networks

Low-power wide-area network (LPWAN) multi-radio access technology (RAT) devices promise enabling Internet of Things (IoT) use-cases that simultaneously require high coverage and data rates, and low energy consumption. For such devices, active probing is usually used for discovering if communication between a mobile terminal (MT) and a base station (BS) or a handover of the MT across LPWAN technologies should be initiated. Because of continuous probing, this procedure increases signaling overhead and energy consumption of the MT. Assuming that the location information of the MT is required for enabling an IoT use-case, this information can potentially also be used for enhancing the discovery and vertical handover procedures in heterogeneous LPWANs. Hence, we propose a location-based mechanism for making discovery and handover decisions in outdoor LPWANs. We do that under the assumption that the location of the MT can be estimated with a certain level of localization errors, while the perfectly accurate location information of the BSs are known to the MT. The mechanism grounds the decisions on the expected SNR between the MT and the BS, which removes the need for continuous probing. If the location information of the MT can be estimated with GPS-like accuracy, we demonstrate that the mechanism can achieve more than 90% correct discovery decisions. We also show that the mechanism is highly accurate in determining if a handover between technologies should be initiated. For an order of magnitude less accurate location information (e.g., for SigFox-based fingerprinting), we show that the mechanism can still make reasonable discovery decisions.

Performance Analysis of Reduced Handoff Interruption Time and Energy Utilization in Cognitive Radio Networks by Unmanned Area Vehicle

The WiMAX (Worldwide Interoperability Microwave Access) is important in communication systems. Mobility is also important in WiMax to achieve high speed in data exchange over the medium. During the exchange of data handoff may be occurred.This paper is focused on handoff in WiMAX and MS (Mobile Station). The Handover Management Algorithm is used to avoid handoff in addition to improve the handover interruption time and to decrease the signaling transaction during the handover procedure we used Global Position System (GPS) to perform handoff faster. GPS has been introduced in this paper to find the position of the MS and BS then the MS will automatically choose BS by routing. We developed a new algorithm to improve the handoff interruption by introducing Time Division Multiple Access (TDMA).The MS finds its position using GPS and find the distance to the SBS (Source Base Station) and nearby BSs. In the next step,MS selects the target BS based on distance. Moreover we combine Handover Management Algorithm (HMA) with Cognitive radio networks (CRNs) for which are the way out for the trouble of underutilizing the license spectrum for which there are more needs in the final pair of decades. The congestion of the wireless spectrum has triggered a stringent contest for panic network resources.

Recommendations for reducing harm and improving quality of care for older people in residential respite care.

Residential respite care (RRC) is a vital service that supports older people and their informal caregivers to continue to live in the community. Older people in RRC have an increased risk of injury-related harm, such as choking and suicide, compared to permanent nursing home residents. However, the opportunities for the prevention of harm during a RRC admission are largely unknown. This study developed recommendations to reduce harm and improve quality of care for older people in RRC. Experts developed, refined and prioritised recommendations through two consultation forums applying the modified nominal group technique and a follow-up online survey. Participants were purposively sampled from an existing network and were selected based on their expertise in aged care practice, nursing, policy, research, caregiver advocacy and quality improvement in the aged and healthcare sectors. Haddon's Matrix, an injury prevention framework, was applied to the recommendations. Final recommendations were released to over 300 organisations for validation and feedback. Five experts were involved in forum one, seven attended forum two, and a further seven completed the survey. Seventeen draft recommendations were developed and refined to 11 final recommendations, four of which were prioritised as most important for implementation. These included the following: (a) a planned preventative care model of RRC; (b) facilities that specialised in RRC; (c) optimising information gathered on RRC residents; and (d) a standardised procedure for admission, handover and discharge from RRC. We received limited feedback from the organisations, which did not alter the recommendations. The recommendations developed in this study provide a valuable basis for the development of strategies to reduce harm and improve care in RRC and are a valuable first step towards improving practice. The next step is to empirically test the suggested recommendations to determine their effectiveness.

Introduction of a formal handover procedure in radiology after changing to a full shift on-call system for registrars

Introduction of a formal handover procedure in radiology after changing to a full shift on-call system for registrars

SOLVER: A Framework for the Integration of Online Social Networks with Vehicular Social Networks

Online social networks (OSNs) are comprised of people with social interactions and relationships, such as friendship and acquaintance. Social web communities (e.g., Facebook or Twitter), and content-sharing sites with social networking functionality (e.g., YouTube), have attracted millions of users, and OSNs are continuing to grow, with a giant number of users. At the same time, new social services are emerging, moving social networking from traditional OSNs toward vehicular social networks (VSNs). VSNs consider a social network where every vehicle is capable of establishing social ties in an autonomous way with other vehicles or drivers/passengers. However, limitations exist in VSNs, such as reduced connectivity due to mobility models and the opportunistic nature of vehicular networks. Similar considerations apply in OSNs, where the centralized architecture may suffer from high traffic load. In this article, the integration of OSNs with VSNs is realized through a hybrid framework that merges the centralized structure of OSNs with the distributed opportunistic nature of VSNs. The proposed hybrid OSN-VSN framework, named SOLVER, allows communications both among different VSNs and toward OSN communities, in order to maintain connectivity and service that can be affected by mobility. Connectivity holes of VSNs can be limited through a handover procedure toward an OSN community, and traffic load in an OSN can be redirected to specific VSNs in order to release network resources in OSNs, with the consequent reduction of transmission delay. SOLVER presents a solution for maintaining connectivity in VSNs and extending it toward OSNs, and vice versa. Security and privacy issues are also addressed through the use of a multi-layer security approach adopted in SOLVER. As a main strength, SOLVER is able to synergistically exploit the positive features of OSNs and VSNs, as well as providing security and privacy, with mechanisms that are completely agnostic to the final users.

Handover among junior doctors: a quality improvement study

Background/Aims Handover is a procedure that ensures efficient transfer of clinical information across teams. It is also an opportunity for junior doctors to develop clinical competencies, communications skills and leadership. Poor handovers can result in delays, clinical errors, duplication of work, poor morale, increased length of hospital stay, and risk of harm to patients. Poor handovers were identified as an area of concern for two successive years in the General Medical Council's survey. Methods Measures were undertaken to address this by updating their handover policy, developing a new handover protocol and instigating rota monitoring by involving junior doctors and consultants through focus groups. A survey was conducted among the same cohort of junior doctors before and after the interventions. Findings There was a remarkable improvement in junior doctors' attitudes towards safety, frequency of face-to-face handover, use of a handover book, and overall positive experiences of the handover procedure. Conclusions It is worth examining the approach to handover among other health professionals and perhaps between professions regarding the same patients.

Significance Risks Evaluation of Commercial Construction Projects

AbstractThe main objective of the article is to present quantified and measurable risks likelihood appearance, impact and significance of inspected and monitored 48 commercial construction projects and their feasibility to be carried out. Original technical, financial and organisational feasibility studies in compliance with a rigorous Bank Investment Supervision requirements have been executed by the author in the period of 2005 – 2018. Methodology of construction project appraisal for financing and execution professional preparation have been laid out – technical documentation, arrangements, realisation. Analysis and assessment of Bank Investment Supervision consisted of project execution plan PEP, geotechnical and environmental conditions, permit design, agreements and decision impacts of local authorities, engineering contract for construction works, project insurance and performance bonds, schedule of execution tasks and their costs, payment plan, investment budget and project economical effectiveness, scope of monthly construction works execution assessed by Earned Value Method approach and handover procedure of construction project. An attempt was made to express numerically the relationship between risks impacts and their level of likelihood. Also, a method of associating the influence of projects risks impacts on the extent of the likelihood of project risk occurrence which makes possible to determine the direction and the strength of this relationship was presented. Finally, risks likelihood appearance, impact and significance variability of commercial construction projects within last two years of booming investment industry have been determined.

Handover based on a predictive approach of signal‐to‐interference‐plus‐noise ratio for heterogeneous cellular networks

In mobile communication networks, the handover procedure enables a continuous communication service for users on the move. However, handovers, handover failures, and ping-pong handovers increase the signalling load in the network, resulting in the use of network resources and a reduction of the system throughput. They also add delay to the transmitted data and even the risk of disconnection in detriment to the quality of experience of the user. Therefore, reducing the handover processes and their errors is an important issue, particularly, in heterogeneous networks that are more prone to trigger handovers due to their configuration with overlapped cells of different sizes. Additionally, heterogeneous networks present a higher percentage of handover errors in comparison with networks only formed by macro-cells. In this work, the authors present a method to adapt the start of the handover based on a prediction of the signal-to-interference-plus-noise ratio. Their proposal reduces handover failures and the probability of ping-pong handovers simultaneously, by determining the appropriate time to safely perform the handover.

Enhanced QoS and QoE Support through Energy Efficient Handover Algorithm for UMTS Architectures

Spectrum inefficiency is a significant issue because of the increasingly more solicitation of transmission capacity by the end clients. Accomplishing high transmission rates and elevated levels of Quality of Service (QoS) speaks to in any case an open issue. Long haul Evolution (LTE) has been proposed as the reason for the fourth era versatile cell systems (4G) that points of the LTE standard are higher client bit rates, lower delays, expanded range proficiency, diminished expense, and operational effortlessness. In any case, this innovation is as yet being worked on and a few open issues must be still explored, for example, obstruction coordination, and power utilization, assets the board and handover procedures. The point of this work is to ensure the decrease of intensity utilization utilizing another handover calculation dependent on green arrangement. Also, the proposed conspire ensures the minimization of superfluous handovers. In any case, the issue in this technique is doesn't mulls over of the impact of green strategies in high force hubs. Along these lines, in the proposed framework the impact of high force hubs are thought of. This situation is expanded more than one full scale cell and various kinds of low force hubs, for example, pico-cell and microcells. In this situation, the force sparing is broke down during the handover strategies. Think about these issues; another strategy is proposed called Dynamic base Station arranging (DBSP) for accomplishing vitality productivity. The fundamental idea is to kill a BS individually that will insignificantly influence the system by utilizing a recently presented thought of system sway, which considers the extra burden increases brought to its neighboring BSs. So as to additionally diminish the flagging and execution overhead over the air and back take, utilize the estimated estimations of system sway as their choice measurements. A trial result shows that the proposed strategy accomplishes high vitality proficiency under different situations. In this work the presentation of an UMTS organize situation is assessed by utilizing different estimations of the priority bits of the CBR application.

Liable, but Not in Control? Ensuring Meaningful Human Agency in Automated Decision‐Making Systems

Automated decision making is becoming the norm across large parts of society, which raises interesting liability challenges when human control over technical systems becomes increasingly limited. This article defines “quasi‐automation” as inclusion of humans as a basic rubber‐stamping mechanism in an otherwise completely automated decision‐making system. Three cases of quasi‐automation are examined, where human agency in decision making is currently debatable: self‐driving cars, border searches based on passenger name records, and content moderation on social media. While there are specific regulatory mechanisms for purely automated decision making, these regulatory mechanisms do not apply if human beings are (rubber‐stamping) automated decisions. More broadly, most regulatory mechanisms follow a pattern of binary liability in attempting to regulate human or machine agency, rather than looking to regulate both. This results in regulatory gray areas where the regulatory mechanisms do not apply, harming human rights by preventing meaningful liability for socio‐technical decision making. The article concludes by proposing criteria to ensure meaningful agency when humans are included in automated decision‐making systems, and relates this to the ongoing debate on enabling human rights in Internet infrastructure.

SFP-based vertical handover with MIH services for integrated Wi-Fi and WIMAX networks

The seamless vertical handover among different wireless systems are required to offer high quality services. It is attained by the developing standard IEEE 802.21 media independent handover (MIH) services. In this paper, single AP scanning, fast ranging and preregistration (SFP) approach is used in which the target AP is chosen based on the proposed idle capacity and signal strength with hybrid PS-GS algorithm. After selecting the target base station (BS), the handover decision algorithm based on SINR enabled with utilising RSSI, available bandwidth and monetary cost. In the proposed vertical handover scenario, the MAC overhead is minimised by reducing the scanning time. The efficiency of the proposed approach is evaluated in terms of scanning time, handover interruption time, handover latency, packet loss, packet delay and throughput. When compared with the existing handover procedures, better results obtained in the proposed handover procedure. The outcomes demonstrate that the hybrid algorithm retains a maximum capacity to escape from local optimums with faster convergence than the standard PSO and GSA.

Reducing Signal Overload by Disconnection Tolerant Voice Service in Heterogeneous Networks

Nowadays, Over-The-Top (OTT) voice call service has become more popular than other Voice over Internet Protocol services provided by mobile operators due to cheaper costs. For devices with more than one network interfaces, the OTT software may need to handover between heterogeneous networks during a call. Unnecessary handover may lead to signal overload, especially in a Wi-Fi intensive area where users may handover frequently between Wi-Fi and cellular networks. For example, if the period between when a user handovers from Wi-Fi to Long Term Evolution (LTE) and when the user handovers from LTE back to Wi-Fi is too short to transmit voice data, the handover procedures between Wi-Fi and LTE can be considered unnecessary and power consuming. To tackle this issue, this paper proposes delay handover mechanism (DHM) to avoid the unnecessary handover procedures by postponing the timing to handover from Wi-Fi to LTE. We then propose an analytical model as well as a simulation model to investigate how many handovers can be reduced. The analytical model is validated against the simulation model. With extensive simulation experiments, the performance evaluation of DHM offers a guideline to configure parameters based on the trade-off between reduced handover ratio and packet loss rate. As a whole, DHM is an application-based mechanism for avoiding unnecessary handovers as well as cutting down LTE usages.

Monitoring of Construction Projects Feasibility by Bank Investment Supervision Approach

Technical, financial and organisational feasibility study methods in compliance with a Bank Investment Supervision requirements have been presented. Methodology of construction project appraisal for financing and execution professional preparation have been laid out – technical documentation, arrangements, realisation. Analysis and assessment of Bank Investment Supervision consisted of Project Execution Plan, geotechnical and environmental conditions, permit design, agreements and decision impacts of local authorities, engineering contract for construction works, project insurance and performance bonds, schedule of execution tasks and their costs, payment plan, investment budget and project economical effectiveness, scope of monthly construction works execution assessed by Earned Value Method approach, significant risks measurable assessment and handover procedure of construction project. Engineering, Project and Construction Management (EPCM) approach to investment process and solid, consequent, regular construction projects monitoring executed by professional Banking Supervision Inspector make possible to minimise any faults of inappropriate financing of construction projects.

Service Migration in Fog Computing Enabled Cellular Networks to Support Real-Time Vehicular Communications

Driven by the increasing number of connected vehicles and related services, powerful communication and computation capabilities are needed for vehicular communications, especially for real-time and safety-related applications. A cellular network consists of radio access technologies, including the current long-term evolution (LTE), the LTE advanced, and the forthcoming 5th generation mobile communication systems. It covers large areas and has the ability to provide high data rate and low latency communication services to mobile users. It is considered the most promising access technology to support real-time vehicular communications. Meanwhile, fog is an emerging architecture for computing, storage, and networking, in which fog nodes can be deployed at base stations to deliver cloud services close to vehicular users. In fog computing-enabled cellular networks, mobility is one of the most critical challenges for vehicular communications to maintain the service continuity and to satisfy the stringent service requirements, especially when the computing and storage resources are limited at the fog nodes. Service migration, relocating services from one fog server to another in a dynamic manner, has been proposed as an effective solution to the mobility problem. To support service migration, both computation and communication techniques need to be considered. Given the importance of protocol design to support the mobility of the vehicles and maintain high network performance, in this paper, we investigate the service migration in the fog computing-enabled cellular networks. We propose a quality-of-service aware scheme based on the existing handover procedures to support the real-time vehicular services. A case study based on a realistic vehicle mobility pattern for Luxembourg scenario is carried out, where the proposed scheme, as well as the benchmarks, are compared by analyzing latency and reliability as well as migration cost.

Spectrum Sharing in Satellite-Mobile Multisystem Using 3D In-Building Small Cells for High Spectral and Energy Efficiencies in 5G and Beyond Era

In this paper, we present a novel technique for sharing satellite spectrum with terrestrial-mobile 3-dimensional (3D) in-building small cells, namely femtocells. Both the space-satellite and the terrestrial-mobile systems (TMSs) operate at their respective licensed spectrums. However, due to the scarcity of the available spectrum, a huge amount of data generated indoors, and a high external wall penetration loss of a 3D building, we propose to reuse the satellite spectrum to small cells deployed only in 3D buildings of the TMS. The proposed spectrum sharing technique is detailed by identifying and addressing the major related issues. The co-channel interference generated because of the co-existence of the satellite user equipments (UEs) in the small-cell coverage is analyzed, and the handover procedures for a satellite UE toward and away from any small cell are discussed. The almost blank subframe (ABS)-based enhanced intercell interference coordination (eICIC) technique is employed to small cells in order to assure the quality-of-service (QoS) between small-cell UEs and satellite UEs. We derive the system-level capacity, spectral efficiency, and energy efficiency performance metrics for the proposed technique by varying the number of buildings over the coverage of a macrocell and deduce the condition for optimality for both the energy efficiency and the spectral efficiency. With an extensive system-level simulation and numerical analysis, we justify the impact of using the ABS-based eICIC technique toward provisioning QoS in terms of radio resource allocation. Furthermore, we show the outperformance of the proposed technique in terms of spectral efficiency and energy efficiency over the ones expected for the fifth generation (5G) network requirements as well as achieved by numerous existing techniques. Finally, we discuss the radio resource scheduler implementation as well as the significance, challenge, and future research perspective of the proposed spectrum sharing technique.

Modeling Handover Signaling Messages in OpenFlow-Based Mobile Software-Defined Networks

The software-defined networking (SDN) paradigm has become essential in tackling several issues and challenges in conventional networking, especially in mobile/cellular networks. In order to realize the benefits brought by SDN to mobility management, we study the effects of SDN in conjunction with OpenFlow protocol on the handover procedure. However, in this new setting, the handover still suffers from delay due to the exchange of OpenFlow signaling messages. In this paper, we focus on SDN in mobile networks and quantify the delays of handover-related OpenFlow messages in order to identify the performance measures as well as the underlying challenges. For our analysis, we provide an analytical model, using which we modeled two handover-related OpenFlow messages in such networks. To the best of our knowledge, no previous work has modeled OpenFlow messages other than Packet-in messages. In this paper, in addition to the Packet-in message, we model Port-status messages. Following our analysis, we propose a novel solution to make handover more efficient and less interruptive. Furthermore, we study our solution in an LTE architecture and compare it to an existing solution. We show that, in normal traffic conditions, our solution can decrease the handover delay as much as 20%.

PPSHA: Privacy preserving secure handover authentication scheme for all application scenarios in LTE-A networks

To ensure secure and seamless handovers inter-Evolved Universal Terrestrial Radio Access Network (E-UTRAN) is a key issue in LTE-A networks. Due to the introduction of Home Evolved NodeB (HeNB), there are three different access modes for the HeNB and the mobility scenarios between the eNB and the HeNB in LTE-A networks are rather complicated. Different handover procedures are executed for different mobility scenarios according to the 3GPP committee, which makes the overall system complex. Thus, it is a key point to propose a unified and secure handover scheme to fit in with all the mobility scenarios in LTE-A networks. In this paper, we propose a secure handover authentication scheme based on the certificateless signcryption technique. Our proposed scheme can achieve the unified and secure handover procedure without sacrificing efficiency. The security and performance evaluations demonstrate that our proposed scheme can meet various security requirements including the perfect forward/backward secrecy and privacy preserving. At the same time, our scheme achieves ideal efficiency.