Handover Process Research Articles

An Optimal Network Selection and Efficient Two Level Cluster-Based Routing Mechanisms for Seamless Vertical Handover in Vehicular Networks

Mobile Ad Hoc Network includes the crucial type Vehicular Ad-hoc Networks, (VANET). In this developed work, nodes are considered from vehicles and transmission capabilities are outfitted with its interconnected vehicles forming a network. Roadside equipment is fixed as all vehicles nearby are equipped with fixed equipment thus enabled communications in real-life application of VANET. In existing methodologies, designs of mobility are required by VANET specifically from Vertical Hand Over decision approach. This fails as of failure in links in networks on focusing issues. Thus, in dissemination of networks, routing is mandatory. Hence, our designed work of Effective two-layer cluster based Routing Mechanism is implemented in VANET to diminish the problems of failures in link. So, hybrid model is incorporated with Biogeography-Based Optimization (BBO) for choosing best available network done and process of vertical handover are done by ant colony optimization. Specific node for vertical handover is chosen based on the weight value from the hybrid model and deploys the SVM classification. On unsteady shape of topology, Effective Two-Level Cluster-based Routing Mechanism is used for maintenance of route. Initially, two clusters are formed with both links as strong and weak from divided nodes to perform routing among cluster members and the best route is chosen by greedy algorithm. High packet delivery ratio and low end to end delay is attained in this proposed approach from the analyzed results against existing methods.

Critical review of building handover-related research in construction and facility management journals

PurposeAlthough the handover stage is the key transition stage between the construction and operation, there is no critical overview of issues and research at the handover stage, hindering the achievement of sustainable development of buildings. Therefore, the purpose of this paper is to review the building handover-related issues and research in construction and facility management (FM) journals. The specific objectives of this study include: analyze the research trends and overview the handover-related publications; identify the major research topics on the handover of buildings; identify research gaps and propose future research directions.Design/methodology/approachThis study opted for a four-step systematic review of papers from the well-known academic journals in the construction and FM respects.FindingsThe results first revealed the increasing research interest in the handover of buildings from the researchers. Moreover, the post-construction defects, poor information fidelity, poor interoperability between building information modeling (BIM) and FM technologies, and insufficient consideration of end users were identified as the most concerned challenges for a building handover. Furthermore, identifying and formalizing information requirements for handover, improving the handover process, and improving the interoperability between BIM and FM were solutions mostly emphasized by researchers.Research limitations/implicationsAs the first systematic review of building handover-related issues and research, this study is the building block for future research on this topic. The findings provide guidance for researchers in the construction and FM research community, and help them form useful collaboration for future research opportunities and find future research directions.Practical implicationsThe identified significant challenges and potential solutions for a building handover could assist practitioners in making rational decisions on developing or adopting relevant technologies, and reshaping their management patterns and working processes. Moreover, the findings could be severed as evidence for policymakers to initiate policies, such as documents e-submission and timely updating BIMs, to achieve the vision of model-based project delivery.Originality/valueThis study contributed to the body of knowledge of sustainable development by providing a new insight to tackle the hindrance to the smooth transition from the construction to the operation.

Experimental evaluation of real-time packets transmission during vertical handover process on mobile ipv6

The Internet user is growing incrementally over the world. Most of them use mobile devices to connect to the internet. They aim to stay in connection every time and everywhere. Thus, they use mobile IP communication to get always connected to the internet while they move to another place. Fortunately, the telco infrastructure has reached many places in the world. Also, the video file transmission is now becoming a new trend, especially a short movie transmitted via social media. The huge of the internet connection caused the scarcity of Internet address. It was anticipated by introducing IPv6 that supported the mobility by presenting the Mobile IPv6. This paper evaluates the performance on the MIPv6 mechanism on transferring video when the user moves to another place that usually different network infrastructure. Therefore, the vertical handover does not disturb the quality of the video transmission. The experimentation results show during the vertical handover, the addition delay and packet loss is low especially when the network is overlap. If the network is not overlap, the main factor for the handover delay and packet loss is the distance between home network and a new network.

ABRAHAM: Machine Learning Backed Proactive Handover Algorithm Using SDN

An important aspect of managing multi access point (AP) IEEE 802.11 networks is the support for mobility management by controlling the handover process. Most handover algorithms, residing on the client station (STA), are reactive and take a long time to converge, and thus severely impact Quality of Service (QoS) and Quality of Experience (QoE). Centralized approaches to mobility and handover management are mostly proprietary, reactive and require changes to the client STA. In this paper, we first created an Software-Defined Networking (SDN) modular handover management framework called HuMOR, which can create, validate and evaluate handover algorithms that preserve QoS. Relying on the capabilities of HuMOR, we introduce ABRAHAM, a machine learning backed, proactive, handover algorithm that uses multiple metrics to predict the future state of the network and optimize the load to ensure the preservation of QoS. We compare ABRAHAM to a number of alternative handover algorithms in a comprehensive QoS study, and demonstrate that it outperforms them with an average throughput improvement of up to 139%, while statistical analysis shows that there is significant statistical difference between ABRAHAM and the rest of the algorithms.

Testbed evaluation of a seamless handover mechanism for an SDN-based enterprise WLAN

Many modern-day applications require seamless connectivity to provide a good quality experience to mobile users. Thus, mobility management mechanism becomes a crucial aspect of all the wireless technologies used to connect to the Internet. In this letter, we present the testbed implementation details of a Network Address Translation (NAT)-based, client-unaware, seamless handover mechanism for a Software-Defined Enterprise WLAN framework. The results from the testbed implementation corroborate that the handover mechanism can provide uninterrupted connectivity during a handover process.

Enhanced Intersystem Handover Algorithm for Heterogeneous Wireless Networks

Current and future wireless network architectures consist of several access technologies to support numerous traffic types and enable mobile devices to be connected anytime, anywhere. However, providing a rapid seamless connectivity and service continuity between such various access technologies remains a challenge. This is mainly because the previously proposed handover algorithms have failed to predict the future values of the measured received signal strength needed for rapid handover process. In addition, existing handover algorithms are not adaptable to the changes of the network conditions and user preferences. This leads to erroneous network selection, packet loss, and ping-pong effect due to high-ranking abnormality. In this study, an intersystem handover (IH) algorithm has been designed by integrating grey prediction theory, multiple-attribute decision making, fuzzy analytic hierarchy process, and multi-objective optimization ratio analysis. Network Simulator 2 has been applied to evaluate the performance of the proposed IH algorithm when compared to the fuzzy logic-based vertical handover (FLBVH) algorithm and the adaptive neuro-fuzzy inference system (ANFIS) algorithm. On average, the proposed IH algorithm has shown 1.1 s handover delay, 5% packet loss, 1.6% probability of ping-pong effect, and 97.8% better throughput performance than the ANFIS algorithm and FLBVH algorithm, respectively, for a 100-s time interval.

Importance of evaluation for post-disaster assets: a preliminary study in Aceh, Indonesia

Responding to the effects of the earthquake and tsunami in 2004, Badan Rehabilitasi dan Rekonstruksi Nanggroe Aceh Darussalam-Nias (BRR NAD-Nias) was assigned as the coordinating and executing agency for improving the region in Aceh province and Nias islands in Indonesia. The allocation for the projects directly implemented by the BRR was approximately USD 2.6 billion. Based on local regulation, these assets must be turned over to the Aceh government. Although most assets were already occupied, neither an appropriate handover nor external project evaluation was conducted. This preliminary study surveyed opinions from building users regarding building quality, the need for building evaluation, and the general opinion for occupying assets with no appropriate handover process in a post-disaster context. The samples included a school, health center, and a sub-district level government office in Banda Aceh city. This study used descriptive methods and a quantitative approach. Results showed the majority of respondents doubted the quality and condition of the assets and agreed with the importance of conducting asset evaluation. However, they are uncertain whether occupying assets before an appropriate handover was appropriate because the post-disaster situation required assets to be functional as soon as possible.

Analysis on LoRa RSSI in Urban, Suburban, and Rural Area for Handover Signal Strength-Based Algorithm.

This paper focus on analysis on Long Range (LoRa) handover session was conducted in urban, suburban, and rural area in Perlis state, Malaysia. The experiment will consists of observation and analyzed on three area using LoRa communication modules. These three areas were collected on its Received Signal Strength Indicator (RSSI) to know the signal strength over the distance from base station and the differences physical object appear in Line of Sight (LoS) during the transmitting and receiving its signal from LoRa Transmitter to LoRa Receiver. The result at three area of different location have shown various pattern in term of RSSI where the each of the location give the distance that signal of LoRa could reach whilst the motion of vehicle is constant. From this experiment, certain level of RSSI value will be chosen to set as minimum boundary switcher for handover process state indicator and be used handover process algorithm in network switcher.

Postoperative handover among nurses in an orthopedic surgical setting in Myanmar: a best practice implementation project.

The aim of this project was to improve the postoperative handover practice within the local context of an orthopedic surgical setting by implementing best practice. Clinical handover is a communicative process where the responsibility of patient care is transferred through the exchange of patient information between the care providers. Postoperative handover is an important phase of perioperative care that presents challenges to handover personnel due to transitions in care throughout the perioperative period and the inability of surgical patients to participate in their own care. This paper reports on the best practice implementation project conducted in the field of postoperative handover among nurses in a 500-bed orthopedic surgical setting in Myanmar in 2017. The project used the JBI Practical Application of Clinical Evidence System and the Getting Research into Practice audit tool to conduct a baseline audit and two follow-up audits. A total of 120 postoperative handovers were observed and data were collected. Education sessions and a series of discussion and engagement efforts were employed to increase the compliance with evidence-based postoperative handover practice. Baseline audit showed low compliance in audit criteria 3, 5 and 6, whereas varying compliance was observed in criteria 1, 2 and 4. Improvement was seen with five criteria in follow-up audits except for criterion 1. Compliance with criterion 1 was inconclusive because staff attendance at postoperative handovers varied, depending on patients' different handover needs. Nurses attendance, however, improved through engagement efforts and education sessions. We were able to make significant improvements in the underperforming areas related to postoperative patient handover. This project confirms that an SBAR (Situation, Background, Assessment, Recommendation) checklist has been implemented to navigate and document every postoperative handover at the main operating theater; the handover process at the intensive care unit complies with the COLD (Connect, Observe, Listen, Delegate) process; and attendance of handovers by nurses has increased. It is recommended that regular audits be conducted to sustain the change and improve where required.

Ping-pong reduction for handover process using adaptive hysteresis margin: a methodological approach

The technology, Long Term Evolution (LTE) developed by 3rd Generation Partnership Project is considered an improved standard in mobile communications when compared to previously attained network standards. LTE with prospects of decreased latency levels and support of downlink and uplink transmission at data rates exceeding 100Mbps and 50Mbps, an effective handover framework needs to be put in place to improve quality of service rendered to the network users and decrease wastage of network resources. This study examines several works carried out on a handover criteria (hysteresis margin) needed for designing an effective handover framework. This margin is based on the received signal strength between both target and serving eNodeBs, and its proper determination amongst other advantages mitigates the rate of unnecessary and repeated handover (ping-pong effect). The model presented in this research integrates the artificial neural network (ANN) mechanism into the determination of hysteresis margin in the LTE handover process which is to minimize handover delay and ping-pong taking into consideration the speed of the user equipment (UE).

Bio-inspired Seamless Vertical Handover Algorithm for Vehicular Ad Hoc Networks

One of the most important factors to implement VANET is by considering the variety of wireless networks available around the city as well as the vehicles traffic scenarios. However, by providing a diverse range of wireless access technologies, it is necessary to provide continuous network connectivity as well as selecting the most suitable network technology and performance. Many researchers have worked on building algorithms for selecting the best network to improve the handover process. However, with high-speed vehicles mobility, the vertical handover process became the most challenging task in order to achieve realtime network selection. This paper proposes a bio-inspired network selection algorithm influenced by insect's behaviour which combines Artificial Bee Colony (ABC) and Particle Swarm Optimization (PSO). The proposed algorithm is applied to process multi-criteria parameters to evaluate the best available network and then execute the handover process seamlessly. The results demonstrate the benefits of the proposed Multi-Criteria ABC-PSO method by reducing the handover decision delays by 25%. It gives the optimum performance in terms of network selections and reduces the handover latency by 14.5%. The proposed algorithm also reduces the number of unnecessary handovers by 48% for three different mobility scenarios based on traffic environments (highway, urban and traffic jam).

A flexible IPv6 mobility management architecture for SDN‐based 5G mobile networks

AbstractWith the advent of increasingly diverse services, applications, and use cases, the 5G mobility environment is expected to be highly heterogeneous. The distributed mobility management (DMM) is emerging as a promising approach for 5G, which provides decentralized handover and traffic management at the edge of the network. However, in order to meet the disparate mobility needs, the DMM process requires flexible design considerations. This paper presents a novel mobile node (MN) centered, software‐defined networking (SDN)–based flexible mobility management architecture, named adaptive multimode mobility management (A3M), which can adaptively operate in multiple modes. The proposed A3M architecture incorporates a novel handover mode selection phase among the traditional handover phases during which a suitable mode of handover operation is evaluated. This makes the A3M handover process adaptable to the varying mobility requirements of the MN and enables it to provide differentiated handover management for MNs with different mobility profiles. The performance analysis of A3M shows that it offers optimal handover performance in terms of primary handover performance metrics such as session disruption delay, packet losses, and signaling costs, compared to the popular network‐based DMM approaches.

An effective handover management based on SINR and software‐defined network over urban vehicular ad hoc networks

AbstractUrban vehicular ad hoc network (UVANET) is a modality of high‐topology variation MANET where vehicles travel across constrained layout of the roads and tall buildings, which eventually results in shadowing effects. One of the critical challenges in UVANET is the handover process that happens when a vehicle changes its association with the roadside unit. Urban area suffers from high vehicular density at traffic signals, and vehicle slowdowns caused by speed limits, frequent link disconnection caused by signal attenuation due to obstacles. Thus, it is difficult for UVANET to disseminate the packets to their destinations located in a specified area. This paper presents an effective handover management that calculates the signal‐to‐interference‐plus‐noise ratio (SINR) to ultimately determine the optimal cluster head for seamless handover in UVANET. It also utilizes the software‐defined network to resolve the problem of handover failure in UVANET. The finding in the experimental results shows that the developed association clustering mechanism based on SINR significantly outperforms the baseline association mechanism. More importantly, it can resolve different types of handover problems that improved the quality of service in terms of throughput, handover latency, packet loss ratio, and handover failure ratio, when compared to the baseline handover mechanisms.

A novel modeling approach for vertical handover based on dynamic k-partite graph in heterogeneous networks

The future network world will be embedded with different generations of wireless technologies, such as 3G, 4G and 5G. At the same time, the development of new devices equipped with multiple interfaces is growing rapidly in recent years. As a consequence, the vertical handover protocol is developed in order to provide ubiquitous connectivity in the heterogeneous wireless environment. Indeed, by using this protocol, the users have opportunities to be connected to the Internet through a variety of wireless technologies at any time and anywhere. The main challenge of this protocol is how to select the best access network in terms of Quality of Service (QoS) for users. For that, many algorithms have been proposed and developed to deal with the issue in recent studies. However, all existing algorithms permit only the selection of one access network from the available networks during the vertical handover process. To cope with this problem, in this paper we propose a new approach based on k-partite graph. Firstly, we introduce k-partite graph theory to model the vertical handover problem. Secondly, the selection of the best path is performed by a robust and lightweight mechanism based on cost function and Dijkstra’s algorithm. The experimental results show that the proposed approach can achieve better performance of QoS than the existing algorithms for FTP traffic and video streaming.

Ethanol: A Software-Defined Wireless Networking architecture for IEEE 802.11 networks

Wireless Networks have become ubiquitous to support the growing demand from mobile users, and other devices, like in the Internet of Things (IoT). This article proposes a Software-Defined Wireless Networking architecture specialized in 802.11 Wireless LANs, called Ethanol, which provides a more fine-grained control. Ethanol is the first wireless SDN architecture that extends the control to the user devices. Further, Ethanol allows intelligent white-box control with finer grain than the state of the art, since it is optimized for WiFi. The proposed architecture is evaluated on a prototype over three use cases. Ethanol can be deployed in any Access Point (AP) running embedded Linux, since it has a negligible overhead — up to 1% in memory and 0.1% in CPU usage. Our results show that Ethanol dynamically alter the throughput of an application up to 3x during a prioritization period, returning bandwidth to other applications outside this period. Only by controlling the best time to perform the handover, our results show about 45% improvement over the traditional signal-based handover process.

High-Speed Railway Communication System Using Linear-Cell-Based Radio-Over-Fiber Network and Its Field Trial in 90-GHz Bands

A linear-cell-based radio-over-fiber (LC-RoF) system is proposed and demonstrated for efficient mobile communication in high-speed trains without hard handover processes. The configuration of the LC-RoF network and possible router architectures are discussed for the field trial test of the proposed system and for advanced systems in the future. Via the LC-RoF network, 90-GHz, millimeter-wave radio access between the ground and a train car is operated in a centralized manner. The resulting throughput of 1.5 Gbit/s is achieved in the field trial test, which is comprised of 250-Mbaud four-subcarrier differential quadrature phase-shift keying with a forward-error correction code implemented in field-programmable gate arrays to the Shinkansen train traveling at 240 km/h without any interruptions in the connections at the change of radio access units.

ST-Elevation Myocardial Infarction: A Simulation Case for Evaluation of Interprofessional Performance in a Hospital.

Introduction Interprofessional collaboration between units in a hospital is essential in order to reach desired time for primary percutaneous intervention (PCI) in acute ST-Segment Elevation Myocardial Infarction (STEMI) cases. We developed a simulation to engage various medical and nonmedical staff in interprofessional and interunit team collaboration. Method We used a scenario in this simulation. Beginning in the emergency department, it detailed a 50-year-old male presenting with progressive chest pain since 7 hours before admission. The emergency team directly examined the patient, and STEMI diagnosis was made, followed by sending the patient to the cardiac catheterization laboratory to undergo primary PCI. A resuscitation kit was required for the simulation. An evaluation sheet was prepared to evaluate every step of patient management. Three judges observed the simulation. At the end of the simulation, debriefing was done, and recommendation for the simulation was discussed. Besides medical activities during patient management, interprofessional communication, administration activities, consultations, and handover process were also evaluated. Results The team achieved the appropriate door-to-electrocardiogram (ECG) time in 8 minutes, but overall target was delayed since door-to-skin puncture time was reached in 110 minutes. Some factors that contributed to these conditions were long waiting time during patient admission, several attempts for telephone consultation to the cardiologist, and prolonged admission process in the cardiac catheterization laboratory. Conclusions The simulation was well received by both participant and our institution, stating that it is a valuable resource for developing interdisciplinary learning program. This simulation also contributed to the development of the clinical pathway, STEMI protocol, in our institution.

Learning the value of providing a good handover

The handover process can be nerve-wracking for novices. A third-year student shares her advice on how to cope

"You Want Me to Assess What?": Faculty Perceptions of Assessing Residents From Outside Their Specialty.

Competency-based medical education (CBME) demands that residents be directly observed performing clinical tasks; however, many faculty lack assessment expertise, and some programs lack resources and faculty numbers to fulfill CBME's mandate. To maximize limited faculty resources, the authors explored training and deploying faculty to assess residents in specialties outside their own. In spring 2017, 10 MD and 2 PhD assessors at a medium-sized medical school in Ontario, Canada, participated in a 4-hour training session, which focused on providing formative assessments of patient handover, a core competency of medical practice. Assessors were deployed to 2 clinical settings outside their own specialty-critical care and pediatrics-each completing 11 to 26 assessments of residents delivering patient handover. Assessors were subsequently interviewed regarding their experiences. While assessors felt able to judge handover performance outside their specialty, their sense of comfort varied with their own prior experiences in the given settings. Lack of familiarity with the process of handover in a specific setting directly influenced assessors' perceptions of their own credibility. Although assessors identified the potential benefits of cross-specialty assessment, they also cited challenges to sustaining this approach. Findings indicate a possible "contextual threshold" for cross-specialty assessment: tasks with high context specificity might not be suitable for cross-specialty assessment. Introducing higher-fidelity simulation into the training protocol and ensuring faculty members are remunerated for their time are necessary to establish future opportunities for shared assessment resources across training programs.

Investigation of Internet of Things Handover Process for Information Centric Networking and Proxy Mobile Internet Protocol

IoT (Internet of Things) technically connects billions of entities to the Internet. The IoT is divided between the technology and the service itself. As a result, great efforts are needed to join data from many contexts and services. This reason has motivated proposals to develop solutions that can overcome existing issues of limitations for mobility, security, reliability and scalability of IoT. These billions of devices are interconnected to each other either using unicast, multicast or broadcast communications, and mixture of static and mobile communications. This paper aims to investigate the parameters of mobility performance in handover process for mobile multicast IoT environment. Investigation is done quantitatively by evaluating the parameters of handover process for IoT in two networking protocols that are possible to support acceptable mobility performance for IoT. The protocols are ICN (Information Centric Networking) and Proxy Mobile Internet Protocol. The evaluation parameters include packet loss and service recovery time. The metrics are extracted from the handover process flow for each network protocol topology. The service recovery time parameter is assumed as the time duration for each message to travel from sender to receiver, while packet loss parameter depends on the packet arrival rate and service recovery time. The results show that the ICN performs better than Proxy Mobile Internet Protocol.