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Deep-reinforcement-learning-based robot motion strategies for grabbing objects from human hands
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作者 Zeyuan CAI Zhiquan FENG +2 位作者 Liran ZHOU Xiaohui YANG Tao XU 《Virtual Reality & Intelligent Hardware》 EI 2023年第5期407-421,共15页
Background Robot grasping encompasses a wide range of research areas;however, most studies have been focused on the grasping of only stationary objects in a scene;only a few studies on how to grasp objects from a user... Background Robot grasping encompasses a wide range of research areas;however, most studies have been focused on the grasping of only stationary objects in a scene;only a few studies on how to grasp objects from a user's hand have been conducted. In this paper, a robot grasping algorithm based on deep reinforcement learning (RGRL) is proposed. Methods The RGRL takes the relative positions of the robot and the object in a user's hand as input and outputs the best action of the robot in the current state. Thus, the proposed algorithm realizes the functions of autonomous path planning and grasping objects safely from the hands of users. A new method for improving the safety of human-robot cooperation is explored. To solve the problems of a low utilization rate and slow convergence of reinforcement learning algorithms, the RGRL is first trained in a simulation scene, and then, the model para-meters are applied to a real scene. To reduce the difference between the simulated and real scenes, domain randomization is applied to randomly change the positions and angles of objects in the simulated scenes at regular intervals, thereby improving the diversity of the training samples and robustness of the algorithm. Results The RGRL's effectiveness and accuracy are verified by evaluating it on both simulated and real scenes, and the results show that the RGRL can achieve an accuracy of more than 80% in both cases. Conclusions RGRL is a robot grasping algorithm that employs domain randomization and deep reinforcement learning for effective grasping in simulated and real scenes. However, it lacks flexibility in adapting to different grasping poses, prompting future research in achieving safe grasping for diverse user postures. 展开更多
关键词 Robot grasping Deep reinforcement learning Domain randomization Human-to-robot handovers Human-machine collaboration
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OTFS-Based Efficient Handover Authentication Scheme with Privacy-Preserving for High Mobility Scenarios
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作者 Dawei Li Di Liu +1 位作者 Yu Sun Jianwei Liu 《China Communications》 SCIE CSCD 2023年第1期36-49,共14页
Handover authentication in high mobility scenarios is characterized by frequent and shortterm parallel execution.Moreover,the penetration loss and Doppler frequency shift caused by high speed also lead to the deterior... Handover authentication in high mobility scenarios is characterized by frequent and shortterm parallel execution.Moreover,the penetration loss and Doppler frequency shift caused by high speed also lead to the deterioration of network link quality.Therefore,high mobility scenarios require handover schemes with less handover overhead.However,some existing schemes that meet this requirement cannot provide strong security guarantees,while some schemes that can provide strong security guarantees have large handover overheads.To solve this dilemma,we propose a privacy-preserving handover authentication scheme that can provide strong security guarantees with less computational cost.Based on Orthogonal Time Frequency Space(OTFS)link and Key Encapsulation Mechanism(KEM),we establish the shared key between protocol entities in the initial authentication phase,thereby reducing the overhead in the handover phase.Our proposed scheme can achieve mutual authentication and key agreement among the user equipment,relay node,and authentication server.We demonstrate that our proposed scheme can achieve user anonymity,unlinkability,perfect forward secrecy,and resistance to various attacks through security analysis including the Tamarin.The performance evaluation results show that our scheme has a small computational cost compared with other schemes and can also provide a strong guarantee of security properties. 展开更多
关键词 high mobility condition handover authentication PRIVACY-PRESERVING TAMARIN OTFS
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Reinforcement Learning-Based Handover Scheme with Neighbor Beacon Frame Transmission
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作者 Youngjun Kim Taekook Kim +2 位作者 Hyungoo Choi Jinwoo Park Yeunwoong Kyung 《Intelligent Automation & Soft Computing》 SCIE 2023年第4期193-204,共12页
Mobility support to change the connection from one access point(AP)to the next(i.e.,handover)becomes one of the important issues in IEEE 802.11 wireless local area networks(WLANs).During handover,the channel scanning ... Mobility support to change the connection from one access point(AP)to the next(i.e.,handover)becomes one of the important issues in IEEE 802.11 wireless local area networks(WLANs).During handover,the channel scanning procedure,which aims to collect neighbor AP(NAP)information on all available channels,accounts for most of the delay time.To reduce the channel scanning procedure,a neighbor beacon frame transmission scheme(N-BTS)was proposed for a seamless handover.N-BTS can provide a seamless handover by removing the channel scanning procedure.However,N-BTS always requires operating overhead even if there are few mobile stations(MSs)for the handover.Therefore,this paper proposes a reinforcement learning-based handover scheme with neighbor beacon frame transmission(MAN-BTS)to properly consider the use of N-BTS.The optimization equation is defined to maximize the expected reward tofind the optimal policy and is solved using Q-learning.Simulation results show that the proposed scheme outperforms the comparison schemes in terms of the expected reward. 展开更多
关键词 Channel scanning HANDOVER handover delay IEEE 802.11 WLANS Q-LEARNING reinforcement learning
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Dynamic MmWave Channel Reconstruction of MIMO OTA Testing for Handover Scenarios
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作者 Nan Ma Jinyu Wang +3 位作者 Jianqiao Chen Xiaoqi Qin Ping Zhang Baoling Liu 《China Communications》 SCIE CSCD 2023年第4期26-40,共15页
The evaluation of handover performance is essential for ensuring seamless user experience under innovative application scenarios in the fifth generation(5G)and beyond era,including autonomous driving,mobile augmented ... The evaluation of handover performance is essential for ensuring seamless user experience under innovative application scenarios in the fifth generation(5G)and beyond era,including autonomous driving,mobile augmented and virtual reality.However,due to the hardware constrains of a sectored multiprobe anechoic chamber(SMPAC),switching among multiple channel models is of low precision with a high cost in traditional over-the-air(OTA)test solutions.In this paper,we present an efficient and repeatable emulation strategy to reconstruct dynamic millimeter-wave(mm Wave)channels in laboratories for multiple-input multiple-output(MIMO)mobile devices.Firstly,we propose a novel evaluation metric,called average power angular spectrum similarity percentage(APSP),which minimizes the unexpected impact induced by the indefinite condition of adaptive antenna arrays in mm Wave terminals during handover process.Moreover,we propose a partitioned probe configuration strategy by designing a beam directivitybased switching circuit,which enables quick changes of probe configurations in SMPAC.Simulation results demonstrate the effectiveness of the proposed algorithms,thus providing a guideline for the reconstruction of the dynamic channel in different scenarios with resource limitation. 展开更多
关键词 OTA test SMPAC dynamic channel reconstruction cell handover
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An Intelligent Admission Control Scheme for Dynamic Slice Handover Policy in 5G Network Slicing
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作者 Ratih Hikmah Puspita Jehad Ali Byeong-hee Roh 《Computers, Materials & Continua》 SCIE EI 2023年第5期4611-4631,共21页
5G use cases,for example enhanced mobile broadband(eMBB),massive machine-type communications(mMTC),and an ultra-reliable low latency communication(URLLC),need a network architecture capable of sustaining stringent lat... 5G use cases,for example enhanced mobile broadband(eMBB),massive machine-type communications(mMTC),and an ultra-reliable low latency communication(URLLC),need a network architecture capable of sustaining stringent latency and bandwidth requirements;thus,it should be extremely flexible and dynamic.Slicing enables service providers to develop various network slice architectures.As users travel from one coverage region to another area,the callmust be routed to a slice thatmeets the same or different expectations.This research aims to develop and evaluate an algorithm to make handover decisions appearing in 5G sliced networks.Rules of thumb which indicates the accuracy regarding the training data classification schemes within machine learning should be considered for validation and selection of the appropriate machine learning strategies.Therefore,this study discusses the network model’s design and implementation of self-optimization Fuzzy Qlearning of the decision-making algorithm for slice handover.The algorithm’s performance is assessed by means of connection-level metrics considering the Quality of Service(QoS),specifically the probability of the new call to be blocked and the probability of a handoff call being dropped.Hence,within the network model,the call admission control(AC)method is modeled by leveraging supervised learning algorithm as prior knowledge of additional capacity.Moreover,to mitigate high complexity,the integration of fuzzy logic as well as Fuzzy Q-Learning is used to discretize state and the corresponding action spaces.The results generated from our proposal surpass the traditional methods without the use of supervised learning and fuzzy-Q learning. 展开更多
关键词 5g network slice fuzzy q-Learning slice handover
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Fuzzy Logic Based Handover Authentication in 5g Telecommunication Heterogeneous Networks
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作者 J.Divakaran Arvind Chakrapani K.Srihari 《Computer Systems Science & Engineering》 SCIE EI 2023年第7期1141-1152,共12页
Under various deployment circumstances,fifth-generation(5G)telecommunications delivers improved network compound management with fast communication channels.Due to the introduction of the Internet of Things(IoT)in dat... Under various deployment circumstances,fifth-generation(5G)telecommunications delivers improved network compound management with fast communication channels.Due to the introduction of the Internet of Things(IoT)in data management,the majority of the ultra-dense network models in 5G networks frequently have decreased spectral efficiency,weak handover management,and vulnerabilities.The majority of traditional handover authentication models are seriously threatened,making them vulnerable to a variety of security attacks.The authentication of networked devices is the most important issue.Therefore,a model that incorporates the handover mechanism and authentication model must be created.This article uses a fuzzy logic model to create a handover and key management system that focuses on cloud handover management and authentication performance.In order to decrease delays in 5G networks,the fuzzy logic is built with multiple criteria that aim to reduce the number of executed handovers and target cell selection.The simulation is run to evaluate the model’s performance in terms of latency,spatial complexity,and other metrics related to authentication attack validation. 展开更多
关键词 HANDOVER AUTHENTICATION mobility management fuzzy logic LATENCY 5G IoT MATLAB 3GPP
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Six Generation Load Cells Solution Based Congestion Management Control Purpose
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作者 Chafaa Hamrouni Aarif Alutaybi 《Computers, Materials & Continua》 SCIE EI 2023年第3期6445-6460,共16页
Several assessing efforts are approved making both communication and information technologies available.In addition to being a part of universal access and service,we aim at assessing the impact of radio access techno... Several assessing efforts are approved making both communication and information technologies available.In addition to being a part of universal access and service,we aim at assessing the impact of radio access technologies on universal access indicators.The proposed work demonstrates the possibility of inter-working of all existing Radio Access Technologies(RATs),in a limited area presented in the Six Generation Radio Resources Allocation(6 G-A)network.We propose a solution for the Vertical hand Over(VHO)in 6 G-A heterogeneous system,that adopts Media Independent Handover(MIH)protocol to benefit between different used technologies in a direct communication firstly and facilitate,in addition,coordination between congestion controlmechanisms with themobilitymanagement entity.The mathematical model has been developed to deal with locality coverage and broadband needs,based on a methodological approach consisting in integrating parameters linked to access index through radio technologies.This approach has been applied.In practice,it has contributed to highlighting its relative simplicity of implementation,but it is not enough for sixgeneration system radio access networks.The congestion control mechanism is integrated within the vertical handover process,this proposition is used to prevent each presented congestion state.The media independent handover IS equipment,as well as six G-A equipment which are both considered as the whole architecture key equipment,perform and guaranty this related process.Efficient communication is established besides information exchange between various technologies.Achieved evaluation results are performant and prove that proposed mechanisms are efficient.Both simulation and tests results are accomplished. 展开更多
关键词 Long-term evolution-advanced media independent handover point of service point of attachment vertical hand over radio access technology sixth generation
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BE-RPL:Balanced-load and Energy-efficient RPL
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作者 S.Jagir Hussain M.Roopa 《Computer Systems Science & Engineering》 SCIE EI 2023年第4期785-801,共17页
Internet of Things(IoT)empowers imaginative applications and permits new services when mobile nodes are included.For IoT-enabled low-power and lossy networks(LLN),the Routing Protocol for Low-power and Lossy Networks(... Internet of Things(IoT)empowers imaginative applications and permits new services when mobile nodes are included.For IoT-enabled low-power and lossy networks(LLN),the Routing Protocol for Low-power and Lossy Networks(RPL)has become an established standard routing protocol.Mobility under standard RPL remains a difficult issue as it causes continuous path disturbance,energy loss,and increases the end-to-end delay in the network.In this unique circumstance,a Balanced-load and Energy-efficient RPL(BE-RPL)is proposed.It is a routing technique that is both energy-efficient and mobility-aware.It responds quicker to link breakage through received signal strength-based mobility monitoring and selecting a new preferred parent reactively.The proposed system also implements load balancing among stationary nodes for leaf node allocation.Static nodes with more leaf nodes are restricted from participating in the election for a new preferred parent.The performance of BE-RPL is assessed using the COOJA simulator.It improves the energy use,network control overhead,frame acknowledgment ratio,and packet delivery ratio of the network. 展开更多
关键词 COOJA simulator energy HANDOVER internet of things BE-RPL load balancing low-power and lossy network mobility routing protocols RPL
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Recognizing Early Warning Signs (EWS) in Patients Is Critically Important
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作者 Shamsa Samani Salma Amin Rattani 《Open Journal of Nursing》 2023年第1期53-64,共12页
Introduction: Monitoring vital signs is a basic indicator of a patient’s health status and allows prompt detection of delayed recovery or adverse effects and early intervention. Patients with adverse events during ho... Introduction: Monitoring vital signs is a basic indicator of a patient’s health status and allows prompt detection of delayed recovery or adverse effects and early intervention. Patients with adverse events during hospitalization often display clinical decline for several hours before the event is observed. Non-critical care Nurses’ inconsistent recognition and response to patient deterioration lead to an increase in the length of hospital stay, unexpected admissions to the ICU, and increased morbidity and mortality. Aim: The study aimed to assess the factors that facilitate or impede the detection of early warning signs among adult patients hospitalized in tertiary care settings. Training should be provided to improve nurses’ knowledge, practice and attitude toward early warning signs of deteriorating patients leading to enhanced clinical judgment, skills and decision-making in addressing alerts. Methodology: A literature search was carried out in various databases;these were Cumulative Index to Nursing and Allied Health Literature (CINHAL), Google Scholar, PubMed, Science Direct, and Sage. The search area was narrowed from 2017 to 2022. The keywords used were “prevalence” AND “unplanned ICU admission”, “the importance of early warning signs” “outcome failure in rescue” “patient deterioration, communication” “improvement in early detection” AND “patient outcome admission” AND “early warning signs” AND “Pakistan”. After the analysis process, around 33 articles that met the inclusion criteria and were most relevant to the scope and context of the current study were considered. Conclusion: Most of the studies had reviewed literature in a qualitative retrospective observational study, content analysis, mixed method, and quasi-experimental study. The literature review identified that long hours of shift, nurse staffing levels, missed vital signs, lack of nursing training and education, and communication impact nurses’ ability to recognize and respond to early warning signs. 展开更多
关键词 Early Warning Signs Handover Communication Long Hours Rapid Response Team Just in Time Training
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Handover研究综述 被引量:2
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作者 杜文峰 贾维嘉 《计算机工程与应用》 CSCD 北大核心 2005年第21期142-145,共4页
随着无线网络技术的快速发展,怎样使用户正在进行的网络服务在用户移动过程中不被中断,使正在进行的服务能够在基站之间平滑过渡一直受到人们的广泛关注。设计一种高效、稳定的服务切换算法成为当前服务切换领域研究的热点问题。本文详... 随着无线网络技术的快速发展,怎样使用户正在进行的网络服务在用户移动过程中不被中断,使正在进行的服务能够在基站之间平滑过渡一直受到人们的广泛关注。设计一种高效、稳定的服务切换算法成为当前服务切换领域研究的热点问题。本文详细地介绍了现有部分服务切换算法和协议,以及相应算法的优点和缺点,并对服务切换算法进行了分类。文中对服务切换领域当前研究的现状进行了说明,并在讨论中介绍了今后的研究方向。 展开更多
关键词 HANDOVER 移动IP无线网络 延迟分析 服务切换分类 评价标准
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语音连续性技术SRVCC性能分析与优化 被引量:4
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作者 刘晓宇 姜怡 《电信科学》 北大核心 2009年第S2期125-131,共7页
本文主要研究候选技术SRVCC在LTE(TD-LTE和LTE-FDD)与TD-SCDMA和GSM系统之间互操作时,语音业务保持连续性的技术性能及可能的优化方案。通过对SRVCC流程参考实验数据和目前3GPP标准化的SRVCC的主要问题(切换时延长、信令流程复杂等)的... 本文主要研究候选技术SRVCC在LTE(TD-LTE和LTE-FDD)与TD-SCDMA和GSM系统之间互操作时,语音业务保持连续性的技术性能及可能的优化方案。通过对SRVCC流程参考实验数据和目前3GPP标准化的SRVCC的主要问题(切换时延长、信令流程复杂等)的深入研究,初步探讨这些问题的优化思路,最后介绍了SRVCC优化技术的国际标准化进展。 展开更多
关键词 移动通信 网络互操作 LTE inter-RAT HANDOVER SRVCC UTRAN GERAN VOIP
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一种应用于Mobile IPv6中切换算法的分析与改进 被引量:1
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作者 吕晓吾 蒋祥刚 栾新 《计算机工程》 CAS CSCD 北大核心 2005年第21期107-109,共3页
MobileIPv6为全球的移动数据通信提供了一个平台。当一个通信主机在不同的子网间移动时,希望在进行切换的时间段内仍能保持通信的连贯和通信的性能。该文介绍了一个切换算法,分析了它的不足,并提出了自己的改进算法。
关键词 MOBILE IP IPV6 HANDOVER L2 HANDOVER
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Dynamic channel reservation scheme based on priorities in LEO satellite systems 被引量:8
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作者 Jian Zhou Xiaoguo Ye +2 位作者 Yong Pan Fu Xiao Lijuan Sun 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2015年第1期1-9,共9页
According to low earth orbit(LEO) satellite systems with users of different levels, a dynamic channel reservation scheme based on priorities is proposed. Dynamic calculation of the thresholds for reserved channels i... According to low earth orbit(LEO) satellite systems with users of different levels, a dynamic channel reservation scheme based on priorities is proposed. Dynamic calculation of the thresholds for reserved channels is the key of this strategy. In order to obtain the optimal thresholds, the traffic is predicted based on the high-speed deterministic movement property of LEO satellites firstly. Then, a channel allocation model based on Markov is established. Finally, the solution of the model is obtained based on the genetic algorithm. Without user location, this strategy effectively reduces handover failures and improves channel utilization by adjusting dynamically the thresholds according to traffic conditions. The simulation results show that the system's overall quality of service can be improved by this strategy. 展开更多
关键词 dynamic channel reservation PRIORITY HANDOVER different level user low earth orbit(LEO)
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Position-assisted fast handover schemes for LTE-advanced network under high mobility scenarios 被引量:4
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作者 Ming FEI Pingzhi FAN 《Journal of Modern Transportation》 2012年第4期268-273,共6页
Two position-assisted fast handover schemes, scheme A and scheme B, for LTE-A system under very high mobility scenarios, are proposed, together with their performance evaluation. Scheme A is designed to reduce handove... Two position-assisted fast handover schemes, scheme A and scheme B, for LTE-A system under very high mobility scenarios, are proposed, together with their performance evaluation. Scheme A is designed to reduce handover delay by making handover preparation before handover starts. Scheme B aims at reducing unnecessary handovers and improving handover success rate, by calculating the geographically best target handover cell, which makes it easier for mobile terminals to access the target cell. A system level simulation is conducted to evaluate the performance of these two schemes. It is shown that, scheme A could reduce inter-site handover delay by about 50 ms, while scheme B could cut down nearly 50% of all handovers when time-to-trigger (TTT) is 0 ms. Besides, as TTT gets larger, Scheme B has much better success rate. 展开更多
关键词 LTE-A HANDOVER very high mobility handover delay handover frequency handover success rate
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A Trajectory Prediction Based Intelligent Handover Control Method in UAV Cellular Networks 被引量:3
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作者 Bo Hu Hanzhang Yang +1 位作者 Lei Wang Shanzhi Chen 《China Communications》 SCIE CSCD 2019年第1期1-14,共14页
The airborne base station(ABS) can provide wireless coverage to the ground in unmanned aerial vehicle(UAV) cellular networks.When mobile users move among adjacent ABSs,the measurement information reported by a single ... The airborne base station(ABS) can provide wireless coverage to the ground in unmanned aerial vehicle(UAV) cellular networks.When mobile users move among adjacent ABSs,the measurement information reported by a single mobile user is used to trigger the handover mechanism.This handover mechanism lacks the consideration of movement state of mobile users and the location relationship between mobile users,which may lead to handover misjudgments and even communication interrupts.In this paper,we propose an intelligent handover control method in UAV cellular networks.Firstly,we introduce a deep learning model to predict the user trajectories.This prediction model learns the movement behavior of mobile users from the measurement information and analyzes the positional relations between mobile users such as avoiding collision and accommodating fellow pedestrians.Secondly,we propose a handover decision method,which can calculate the users' corresponding receiving power based on the predicted location and the characteristic of air-to-ground channel,to make handover decisions accurately.Finally,we use realistic data sets with thousands of non-linear trajectories to verify the basic functions and performance of our proposed intelligent handover controlmethod.The simulation results show that the handover success rate of the proposed method is 8% higher than existing methods. 展开更多
关键词 UAV AIRBORNE base STATION HANDOVER control TRAJECTORY prediction deep learning
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Cluster-Based Group Mobility Support for Smart IoT 被引量:2
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作者 Kanwal Imran Nasreen Anjum +5 位作者 Saeed Mahfooz Muhammad Zubair Zhahoui Yang Abdul Haseeb Malik Qazi Ejaz Ali Madeeha Aman 《Computers, Materials & Continua》 SCIE EI 2021年第8期2329-2347,共19页
IPv6 over Low Power Wireless Personal Area Network(6LoWPAN)connects the highly constrained sensor nodes with the internet using the IPv6 protocol.6LoWPAN has improved the scalability of the Internet of Things(IoTs)inf... IPv6 over Low Power Wireless Personal Area Network(6LoWPAN)connects the highly constrained sensor nodes with the internet using the IPv6 protocol.6LoWPAN has improved the scalability of the Internet of Things(IoTs)infrastructure and allows mobile nodes to send packets over the IEEE 802.15.4 wireless network.Several mobility managements schemes have been suggested for handling the registration and handover procedures in 6LoWPAN.However,these schemes have performance constraints,such as increased transmission cost,signalling overhead,registration,and handover latency.To address these issues,we propose a novel cluster-based group mobility scheme(CGM6)for 6LoWPAN.To reduce the signalling cost in the CGM6 scheme,we propose to combine the functions of the Authentication,Authorization and Accounting(AAA)server and Local Mobility Anchor(LMA)in AMAG6(AAA+MAG for 6LoWPAN).AMAG6 acts as a cluster head and exchange its information directly with its neighbouring AMAG6 during the mobility.Furthermore,AMAG6 is responsible for the binding and authentication process.To reduce the transmission cost,we also propose enhancements in registration and Handover procedures.The performance of CGM6 is evaluated through extensive simulations.The simulation results show that CGM6 has reduced the handoff latency by 32%,registration delay by 11%and transmission cost by 37%compared to the state-of-the-art mobility management schemes. 展开更多
关键词 6LoWPAN IoTs mobility management REGISTRATION HANDOVER proxyMIPv6(PMIPv6)
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A novel modeling approach for vertical handover based on dynamic k-partite graph in heterogeneous networks 被引量:2
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作者 Mohamed Lahby Ayoub Essouiri Abderrahim Sekkaki 《Digital Communications and Networks》 SCIE 2019年第4期297-307,共11页
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 i... 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. 展开更多
关键词 Heterogeneous wireless networks Vertical handover K-partite graph Cost function QOS Mininet
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COOPERATIVE DIRECTIONAL INTER-CELL HANDOVER SCHEME IN HIGH ALTITUDE PLATFORM COMMUNICATIONS SYSTEMS 被引量:2
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作者 Li Shufeng Wang Lijie +1 位作者 David Grace Ma Dongtang 《Journal of Electronics(China)》 2011年第2期249-257,共9页
A novel Cooperative Directional inter-cell Handover Scheme(CDHS) for High Altitude Platform(HAP) communications systems is proposed,in which the handover target cell and the two cells adjacent to this handover target ... A novel Cooperative Directional inter-cell Handover Scheme(CDHS) for High Altitude Platform(HAP) communications systems is proposed,in which the handover target cell and the two cells adjacent to this handover target cell work cooperatively to exploit the traffic fluctuation to improve handover performance.Users in the overlap area of the overloaded handover target cell will be forced to handover directionally before their optimal handover boundary in order to free up resources for the handover calls which would otherwise be dropped due to the shortage of resources and queue time out.Simulation results show that the handover call dropping probability is greatly reduced(at least 60%) compared with the general queue handover scheme,with little performance reduction to the call blocking probability,and the Not in the Best Cell(NBC) average time is only increased moderately.Moreover,an optimal cell radius can be achieved for a specific platform speed by minimizing the unified system performance,which is the linear combination of the handover call dropping probability and the NBC average time. 展开更多
关键词 Inter-cell Handover High Altitude Platform(HAP) Dropping probability Blocking Probability
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A software-defined networking approach for handover management with real-time video in WLANs 被引量:3
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作者 Peter Dely Andreas Kassler +6 位作者 Lawrence Chow Nicholas Bambos Nico Bayer Hans Einsiedler Christoph Peylo Daniel Mellado Miguel Sanchez 《Journal of Modern Transportation》 2013年第1期58-65,共8页
To achieve high performance and reliability in video streaming over wireless local area networks (WLANs), one must jointly consider both optimized association to access points (APs) and handover management based o... To achieve high performance and reliability in video streaming over wireless local area networks (WLANs), one must jointly consider both optimized association to access points (APs) and handover management based on dynamic scanning of alternate APs. In this article, we propose a new architecture within the software-defined networking (SDN) framework, which allows stations to be connected to several APs simultaneously and to switch fast between them. We evaluate our system in a real-time testbed and demonstrate that our SDN-based handover mechanism significantly reduces the number and duration of video freeze events and allows for smaller playout buffers. 展开更多
关键词 Openflow Handover - Video streaming
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Practical strategies for increasing efficiency and effectiveness in critical care education 被引量:4
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作者 Maurice F Joyce Sheri Berg Edward A Bittner 《World Journal of Critical Care Medicine》 2017年第1期1-12,共12页
Technological advances and evolving demands inmedical care have led to challenges in ensuring adequate training for providers of critical care. Reliance on the traditional experience-based training model alone is insu... Technological advances and evolving demands inmedical care have led to challenges in ensuring adequate training for providers of critical care. Reliance on the traditional experience-based training model alone is insufficient for ensuring quality and safety in patient care. This article provides a brief overview of the existing educational practice within the critical care environment. Challenges to education within common daily activities of critical care practice are reviewed. Some practical evidence-based educational approaches are then described which can be incorporated into the daily practice of critical care without disrupting workflow or compromising the quality of patient care. It is hoped that such approaches for improving the efficiency and efficacy of critical care education will be integrated into training programs. 展开更多
关键词 Medical EDUCATION Critical care EDUCATIONAL EFFICIENCY EDUCATIONAL efficacy BEDSIDE teaching Flipped classroom Patient handover Multidisciplinary team practice In SITU simulation PROCEDURAL training
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