Handover Policy Research Articles

A Hybrid Handover Scheme for Vehicular VLC/RF Communication Networks.

Visible light communication (VLC) is a promising complementary technology to its radio frequency (RF) counterpart to satisfy the high quality-of-service (QoS) requirements of intelligent vehicular communications by reusing LED street lights. In this paper, a hybrid handover scheme for vehicular VLC/RF communication networks is proposed to balance QoS and handover costs by considering the vertical handover and horizontal handover together judging from the mobile state of the vehicle. A Markov decision process (MDP) is formulated to describe this hybrid handover problem, with a cost function balancing the handover consumption, delay, and reliability. A value iteration algorithm was applied to solve the optimal handover policy. The simulation results demonstrated the performance of the proposed hybrid handover scheme in comparison to other benchmark schemes.

Blockchain-Based Efficient Access Control With Handover Policy in IoV-Enabled Intelligent Transportation System

Blockchain-Based Efficient Access Control With Handover Policy in IoV-Enabled Intelligent Transportation System

Can state-owned enterprises enhance enterprise value when they shift focus to core businesses? Empirical evidence on the transfer of ‘three supplies and one industry’ in China

ABSTRACT This research theoretically analysed how corporate value is enhanced when Chinese state-owned enterprises (SOEs) shift their focus. In our analysis of Chinese SOEs listed in A-shares from 2013 to 2019, we describe their process of returning to their primary business using the ‘three supply and one industry’ (3S1I) handover policy. We conducted a quasi-natural experiment to study whether refocusing on SOEs can improve their value. The research shows that the policy enhances the efficiency of SOEs, thus increasing their value. These results were particularly evident among local SOEs. Moreover, SOE employees’ social responsibility performance may have a negative moderating effect on efficiency, indicating that excessive social responsibility can lead to a loss in efficiency and a reduction in SOE value. We conclude by discussing why SOEs should prioritize improving economic value and then fulfil social responsibilities to enhance social value through social purchasing and other ways. This study contributes to the literature by providing recommendations on improving the value of SOE from the perspective of ‘transferring 3S1I’ and refocusing.

Nursing Handover: Experiences and Perspectives in the Critical Care Unit at Murang’a County Referral Hospital

Continuity in delivery of nursing care to patient in the critical care unit is of utmost importance. Although nurses have a variety of guidelines and formats to conduct the handover, gaps have been detected regarding the contents of the handover and its effects on the continuity of care in the critical care unit. The focus of the study was to explore the experiences and perspectives of nurses with nursing handover in the critical care unit. The study adopted a phenomenological qualitative design. A sample of 9 critical care nurses participated in this study. The study found critical care nurses believed they were individually equipped with adequate knowledge to carry out effective departmental and interdepartmental nursing handover. The existence of handover policies in the critical care unit was considered a major enabler of the handover. The participants also believed that strained human resource, lack of standardized handover tools and deviation from the set handover rules negatively impacted the handover process. Furthermore, they reported perceived insufficiency in the management’s role in handover evaluation and feedback. Moreover, all participants advocated for improvement of the current handover practices for improved quality of patient care as well as sense of self-accomplishment among the nurses. There are pertinent implications in the findings of this research for critical care nurses, nurses in other departments and policy makers. The resultant implication for each group of stakeholders promotes the adoption and formulation of effective handover practices and consequently enhanced quality of patient care through transfer of adequate patient information and sense of self-accomplishment among nurses. Keywords: Nursing handover, experiences, perspectives, critical care unit

Proactive Handover Decision for UAVs with Deep Reinforcement Learning.

The applications of Unmanned Aerial Vehicles (UAVs) are rapidly growing in domains such as surveillance, logistics, and entertainment and require continuous connectivity with cellular networks to ensure their seamless operations. However, handover policies in current cellular networks are primarily designed for ground users, and thus are not appropriate for UAVs due to frequent fluctuations of signal strength in the air. This paper presents a novel handover decision scheme deploying Deep Reinforcement Learning (DRL) to prevent unnecessary handovers while maintaining stable connectivity. The proposed DRL framework takes the UAV state as an input for a proximal policy optimization algorithm and develops a Received Signal Strength Indicator (RSSI) based on a reward function for the online learning of UAV handover decisions. The proposed scheme is evaluated in a 3D-emulated UAV mobility environment where it reduces up to 76 and 73% of unnecessary handovers compared to greedy and Q-learning-based UAV handover decision schemes, respectively. Furthermore, this scheme ensures reliable communication with the UAV by maintaining the RSSI above −75 dBm more than 80% of the time.

Development of a mathematical formulation for handover management in heterogeneous network

The proposed radio network was described as an unbroken–time Markov chain and generates an effective mathematical expression for state probabilities. However, the proposed model was not stretched to combine both the Poisson and the batched Poisson spectrum types. From the title of the work, in similarity to the study in focus, a set of mathematical equations were also formed for the developed model. On the contrary, the study covers 2g, 3g and 4g respectively at the implementation phase. As a stochastic process, Pareto Positive Stable Distribution (PPSD) based on type 2 fuzzy logic principle was used for control in the handover optimisation decision-making process. About this Thesis, Self-Organized Network (SON) was adopted towards increased Quality of Service (QoS) in Het-Net. Also, as a result of the dynamic nature of the signal, based on fuzzy logic, a self-adaptive (optimizing) model was developed to make an intelligent decision based on the predefined membership function. A Markov-based framework was developed by Guidolin, Pappalardo, Zanella & Zorzi (2015) to model the handover process for the mobile subscriber, while an optimum context-dependent handover criterion was generated. The proposed mathematical model was validated by simulations, comparing the performance of the author’s strategy with conservative handover optimization techniques in several scenarios. Lastly, the impact of the handover policy on the subscriber’s performance was depicted and how it can enhance the users’ capability using context information.

Artificial Intelligence for Smart Resource Management in Multi-User Mobile Heterogeneous RF-Light Networks

Recent trends in 5G and beyond wireless networks have encouraged the migration from the already congested radio frequency (RF) spectrum to higher frequency bands. In this context, the ubiquitous presence of lighting systems supports wide scale deployment of wireless communication links via light. However, the susceptibility of light to user mobility hinders its wide adoption. Hence, the coexistence of RF and light-based wireless communications has the potential to offer seamless heterogeneous network (HetNet) coverage through intelligent vertical handover policies in the presence of users' mobility. In this article, we first present new insights on the implementation of realistic indoor mobile optical channels and the impact of crowd mobility on relevant channel statistics. Then, an artificial intelligence (AI)-based framework for efficient resource management in mobile multi-user RF-light HetNets is proposed using a deep learning-empowered optical link predictor and a multiagent reinforcement learning-based link assignment strategy. The proposed AI-based framework helps to lay down the foundations of smart resource management in mobile multi-user HetNets.

Adverse events experienced with intrahospital transfer of critically ill patients: A national survey.

Research that focuses on transfers to and from the intensive care unit (ICU) could highlight important patients’ safety issues. This study aims to describe healthcare workers’ (HCWs) practices involved in patient transfers to or from the ICU.This cross-sectional study was conducted among HCWs during the Saudi Critical Care Society's annual International Conference, April 2017. Responses were assessed using Likert scales and frequencies. Bivariate analysis was used to evaluate the significance of different indicators.Overall, 312 HCWs participated in this study. Regarding transfer to ICUs, the most frequently reported complications were deterioration in respiratory status (51.4%), followed by deterioration in hemodynamic status (46.5%), and missing clinical information (35.5%). Regarding transfers from ICUs to the general ward, the most commonly reported complications were changes in respiratory status (55.6%), followed by incomplete clinical information (37.9%), and change in hemodynamic conditions (29%). The most-used models for communicating transfers were written documents in electronic health records (69.3%) and verbal communication (62.8%). One-fourth of the respondents were not aware of the Situation, Background, Assessment, Recommendation (SBAR) method of patients’ handover. Pearson's test of correlation showed that the HCW's perceived satisfaction with their hospital transfer guidelines showed significant negative correlation with their reported transfer-related complications (r = −0.27, P < .010).Hemodynamic and respiratory status deterioration is representing significant adverse events among patients transferred to or from the ICU. Factors controlling the perceived satisfaction of HCWs involved in patients, transfer to and from the ICU need to be addressed, focusing on their compliance to the hospital-wide transfer and handover policies. Quality improvement initiatives could improve patient safety to transfer patients to and from the ICU and minimize the associated adverse events.

Trajectory Learning, Clustering, and User Association for Dynamically Connectable UAV Base Stations

This work examines trajectory learning, clustering, and user association policies for dynamically connectable unmanned aerial vehicle base stations (UAV-BSs). Here, UAV-BSs are allowed to dynamically form physically-connected collocated antenna arrays that enable joint transmission and cooperative energy sharing among the connected UAV-BSs. The UAVs' trajectories, their clustering decisions, and the user association are jointly determined for the case with static users by maximizing a proportional-fair objective given by the sum log-rate of all users. Then, for the case with dynamic users, the UAVs' trajectory learning, re-clustering, and user handover policies are developed to adapt to changes in the users' locations. In particular, the UAVs' locations are adjusted gradually in each time slot based on a stochastic gradient ascent algorithm, and user handover decisions are made in each time slot based on a reward function that is inspired by the solution in the static case. The clustering decisions are updated every T time slots by combining two UAV clusters or by separating a cluster into two. To determine the transmission schemes in each time slot, a semi-orthogonal user scheduling policy is first employed to determine the users that are served in each time slot. Then, joint design of the transmit beamformers and powers is proposed to maximize the sum of log signal-to-leakage-plus-noise ratio (SLNR) of scheduled users. Simulations are provided to demonstrate the effectiveness of the proposed schemes.

Spatial and Temporal Contextual Multi-Armed Bandit Handovers in Ultra-Dense mmWave Cellular Networks

Although millimeter wave (mmWave) is a promising technology in 5G communication, its severe path attenuation and susceptibility to line-of-sight (LOS) blockage result in much more unpredictable outages than traditional technologies. This special propagation property raises a significant challenge to the mobility management in mmWave cellular networks. Since conventional handover policies purely rely on the measurement of signal strength, they would cause a large number of unnecessary handovers due to the frequent short-term LOS blockage by obstacles, imposing high signaling and energy overhead. In this paper, we propose two novel handover mechanisms to reduce unnecessary handovers by carefully deciding the next base station (BS) a user should handover to, so that the new user-BS connection after the handover can last as long as possible. Without prior knowledge of user’s mobility and environment, the proposed handover mechanisms exploit the empirical distribution of user’s post-handover trajectory and LOS blockage, learned online through a multi-armed bandit (MAB) framework. Depending on the contexts extracted from RSS information, two different MAB problems for handover are formulated, which focus on spatial and space-time contexts, respectively, The results of numerical simulations demonstrate that the proposed contextual handover mechanisms significantly outperform existing counterparts on reducing handovers in all simulated scenarios.

Implementasi Peraturan Serah Simpan Karya Cetak serta Karya Rekam pada Dinas Perpustakaan dan Kearsipan Provinsi Jawa Timur dalam Upaya Mewujudkan Karya Koleksi Nasional

RI Law No. 4 of 1990 updated with RI Law No. 13 of 2018 is very strategic to be used as an instrument in realizing the work of national collections and preserving the work of national culture of children from all regions of Indonesia from Sabang to Merauke. East Java people, publishers, record works producers, universities, local governments, private institutions/ institutions, information users are classified as active and support the Handover and Save Policy of Print and Record Works managed by the East Java Province Library and Archives Service as a deposit/ storage center East Java area collection. Good collaboration and continuity between the East Java Province Library and Archives Service with related parties have shown an increasing number of deposit collections each year and has contributed to the number of Regional Bibliographic Collections and the Indonesian National Bibliography Collection and the Number of Book Publications in Indonesia, meaning that it has succeeded in realizing the work of national collections and has the work of national culture, especially publications from the East Java region.Keywords: implementation of public policies, deposit collections, public libraries

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.

Effect analysis of handover record applying in supply room

Objective To explore the effects of handover record applying in supply room. Methods From July to December 2017, 9 staff in Supply Department of Children's Hospital Affiliated to Capital Institude of Pediatrics were selected as the research subjects by purposive sampling method. The handover policy was established and a handover record sheet was designed with Excel software. The occurrence of nursing events and the nursing managers' satisfaction towards supply room were compared before and after the application of handover record. Results There were 11 nursing events before the application of handover record, and none after. The service satisfaction rate after the intervention was (52.50±5.25) , which was higher than that before (49.09±8.15) , the difference was statistically significant (t=-2.301, P=0.032) . Conclusions The application of handover record sheet can make the communication smoothly, and improve the quality of shift and the satisfaction of nurse managers. Key words: Nurses; Central supply, hospital; Handover record sheet

A human inspired handover policy using Gaussian Mixture Models and haptic cues

A handover strategy is proposed that aims at natural and fluent robot to human object handovers. For the approaching phase, a globally asymptotically stable dynamical system (DS) is utilized, train...

Mobility-Assisted and QoS-Aware Resource Allocation for Video Streaming over LTE Femtocell Networks

&#x0D; The interest on enhanced capabilities of femtocell networks is increasing, since it copes with the dynamics of future cellular networks. Thus, innovative approaches and concepts are required to guarantee successful deployment of this new generation of cellular networks for carrying challenging services (e.g. multimedia applications) under complex network conditions. In this context, we propose a novel approach that enhances the capability of LTE-femtocell networks when dealing with downlink variable bit rate (VBR) video transmission. The idea consists on making a pre-allocation (or reservation) of radio resources (resource blocks and transmit power) based on the knowledge of future required video traffic of connected users. We also make our approach capable of supporting efficient mobility management through an optimized handover policy. In fact a coordination entity is proposed to select the target cell which is more capable to support future video traffic delivery based on a multi-criteria utility function. Simulation results prove the effectiveness of the proposed approach and illustrate the great gains obtained for both the user side (low frame loss ratio) and the network side (low transmit power). &#x0D;

Construct validity and reliability of the Handover Evaluation Scale

To examine the psychometric properties of the Handover Evaluation Scale using exploratory and confirmatory factor analysis. Handover is a fundamental component of clinical practice and is essential to ensure safe patient care. Research indicates a number of problems with this process, with high variability in the type of information provided. Despite the reported deficits with handover practices internationally, guidelines and standardised tools for its conduct and evaluation are scarce. Further work is required to develop an instrument that measures the effectiveness of handover in a valid and reliable way. Secondary analysis of data collected between 2006-2008 from nurses working on 24 wards across a large Australian healthcare service. A sample of 299 nurses completed the survey that included 20 self-report items which evaluated the effectiveness of handover. Data were analysed using exploratory factor analysis and confirmatory factor analysis supported by structural equation modelling. Analyses resulted in a 14-item Handover Evaluation Scale with three subscales: (1) quality of information (six items), (2) interaction and support (five items) and (3) efficiency (three items). A fourth subscale, patient involvement (three items), was removed from the scale as it was not a good measure of handover. The scale is a self-report, valid and reliable measure of the handover process. It provides a useful tool for monitoring and evaluating handover processes in health organisations, and it is recommended for use and further development. Monitoring handover is an important quality assurance process that is required to meet healthcare standards. This reliable and valid scale can be used in practice to monitor the quality of handover and provide information that can form the basis of education and training packages and guidelines to improve handover policies and processes.

Quality of Service in Wireless Cellular Networks Subject to Log-Normal Shadowing

Shadowing is believed to degrade the quality of service (QoS) in wireless cellular networks. Assuming log-normal shadowing, and studying mobile's path-loss with respect to the serving base station (BS) and the corresponding interference factor (the ratio of the sum of the path-gains form interfering BS's to the path-gain from the serving BS), which are two key ingredients of the analysis and design of the cellular networks, we discovered a more subtle reality. We observe, as commonly expected, that a strong variance of the shadowing increases the mean path-loss with respect to the serving BS, which in consequence, may compromise QoS. However, in some cases, an increase of the variance of the shadowing can significantly reduce the mean interference factor and, in consequence, improve some QoS metrics in interference limited systems, provided the handover policy selects the BS with the smallest path loss as the serving one. We exemplify this phenomenon, similar to stochastic resonance and related to the "single big jump principle" of the heavy-tailed log-nornal distribution, studying the blocking probability in regular, hexagonal networks in a semi-analytic manner, using a spatial version of the Erlang's loss formula combined with Kaufman-Roberts algorithm. More detailed probabilistic analysis explains that increasing variance of the log-normal shadowing amplifies the ratio between the strongest signal and all other signals thus reducing the interference. The above observations might shed new light, in particular on the design of indoor communication scenarios.

MDP-based handover policy in wireless relay systems

Abstract Wireless relay transmission has been considered as a supplementary technology for future wireless communication system, and handover is a key element in wireless relay transmissions to support users’ mobility. Handover failure will result in the forced termination of an ongoing call, and a good handover scheme will provide good system performance. This article focuses on the handover decision problem in wireless relay transmission systems. Initially, the architecture of a single-cell relay system is introduced. The handover decision problem is formulated as a Markov decision process (MDP). In the proposed model, a profit function is used to evaluate the quality-of-service of the chosen serving node, and a cost function is used to model processing load and signaling cost. Based on the profit and cost functions, the reward function is formulated. Moreover, the objective is to maximize the expected total reward per connection. The value iteration algorithm is employed to determine the optimal handover policy. Furthermore, the analysis is generalized to multi-cell relay systems. Numerical results show that the proposed MDP-based handover policy is well behaved in wireless relay systems.

The cross layer RMPA handover: a reliable mobility pattern aware handover strategy for broadband wireless communication in a high-speed railway domain

Enhancing the handover process in broadband wireless communication deployment has traditionally motivated many research initiatives. In a high-speed railway domain, the challenge is even greater. Owing to the long distances covered, the mobile node gets involved in a compulsory sequence of handover processes. Consequently, poor performance during the execution of these handover processes significantly degrades the global end-to-end performance. This article proposes a new handover strategy for the railway domain: the RMPA handover, a Reliable Mobility Pattern Aware IEEE 802.16 handover strategy “customized” for a high-speed mobility scenario. The stringent high mobility feature is balanced with three other positive features in a high-speed context: mobility pattern awareness, different sources for location discovery techniques, and a previously known traffic data profile. To the best of the authors’ knowledge, there is no IEEE 802.16 handover scheme that simultaneously covers the optimization of the handover process itself and the efficient timing of the handover process. Our strategy covers both areas of research while providing a cost-effective and standards-based solution. To schedule the handover process efficiently, the RMPA strategy makes use of a context aware handover policy; that is, a handover policy based on the mobile node mobility pattern, the time required to perform the handover, the neighboring network conditions, the data traffic profile, the received power signal, and current location and speed information of the train. Our proposal merges all these variables in a cross layer interaction in the handover policy engine. It also enhances the handover process itself by establishing the values for the set of handover configuration parameters and mechanisms of the handover process. RMPA is a cost-effective strategy because compatibility with standards-based equipment is guaranteed. The major contributions of the RMPA handover are in areas that have been left open to the handover designer’s discretion. Our simulation analysis validates the RMPA handover decision rules and design choices. Our results supporting a high-demand video application in the uplink stream show a significant improvement in the end-to-end quality of service parameters, including end-to-end delay (22%) and jitter (80%), when compared with a policy based on signal-to-noise-ratio information.

셀룰러 펨토 시스템에서 부하 분산을 통한 분산적 부채널 ON/OFF 스케쥴링 기법

셀룰러 펨토 시스템에서 펨토 기지국(f-BS: femto base station)은 좁은 영역에 중복 설치 및 과밀 설치될 수 있다. 이러한 불필요한 설치는 채널을 공유하는 인접 f-BS간 간섭문제를 야기하여서 시스템의 용량과 커버리지에 영향을 미칠 수 있다. 본 논문은 셀룰러 펨토 시스템에서 발생할 수 있는 이러한 성능하락 문제를 해결하기 위하여 강제 핸드오버를 이용한 부하분산과 확률적 자원 이용방법을 제시한다. 제안하는 기법은 중앙 컨트롤러의 조정이 아닌 이웃 f-BS간의 통신을 통한 분산적인 방법이며, f-BS가 주변 정보를 수집하여 스스로 과밀지역에 분포하였음을 인식하고 부하 및 자원 이용의 조절하는 방법을 포함한다. 평균 셀 수율, 사용자당 평균 수율을 바탕으로 제안하는 기법의 성능 향상을 모의실험을 통해 검증하였다. In cellular femto systems, femto Base stations(f-BSs) can be installed unnecessarily and overcrowded in small areas. This will cause an interference problem and it can impact on the capacity, blocking probability, and coverage of femtocells in the shared channel systems. In this paper, we propose a load distribution scheme by using forced handover and probabilistic subchannel scheduling policy to resolve the problem. The proposed scheme operates in distributed manner though communication with neighboring f-BSs, and includes self-detection of overcrowded area and radio resource management based on measurements. We evaluate the performance of the proposed scheme in terms of average cell throughput and average throughput per users.