Handover Performance Research Articles

Enhancing MISP with Fast Mobile IPv6 Security

The Mobile Broadband Association has developed the MIS and MISAUTH protocols as link-layer fast authentication protocols. A combination of MIS and MISAUTH protocols, called as MISP, provides secure and fast connection for a wireless access network, but it has been reported that MISP creates a weak session key and suffers from a denial-of-service attack. In addition, a transaction with an authentication server that is required for every authentication is considered as a delay factor during handovers. In this paper, we present an improvement of MISP that utilizes the fast handover approach of Fast Mobile IPv6 and minimizes an involvement of the authentication server while eliminating identified security drawbacks of MISP. The formal security analysis is performed to verify the correctness of the proposed scheme. Moreover, the handover performance of the proposed scheme is compared with an existing scheme.

A New Cellular Network Structure Deploying Shared Relays with Sectorization

To mitigate inter-cell interference, which causes throughput degradation for cell-edge users, a shared relay with sector antennas that are connected to neighboring base stations (BSs) with optical cable is deployed in the cell boundary. Each sector of the shared relays can be considered a remote antenna directed to the connected BS. By controlling the transmit power, inter-cell interference can be mitigated and high-throughput performance can be achieved. Additionally, better handover performance can be obtained by reducing unnecessary handovers caused by ambiguity in the cell boundary. Through computer simulations with the hexagonal cell structure and the proposed shared relay with three sectors, performance gain of the proposed system deployment was verified.

The Intern Handover: the Gap Between Expectations and Performance

The effective resident handover during transitions of patient care is a skill that is identified as one of the entrustable professional activities (EPAs) required for entering residency training. This study describes the results of an objective structured clinical exam (OSCE) station designed to assess interns’ skills in writing a handover of a standardized patient scenario. In 2015, 130 entering interns, representative of 47 of 125 allopathic medical schools, from 13 residency programs at the University of Florida participated in an OSCE that included a written handover station. A nine-item checklist was used to assess performance of interns on the station. Scores on the station ranged from 11.1 % (1 of 9 items correct) to 88.9 % (8 of 9 items correct). While there were no significant differences in handover performance between males and females or between surgical and non-surgical specialties, interns who graduated from top-50 medical schools performed better than graduates from the medical schools not ranked in the top 50. However, the overall failure rate on the handover station was 73 %. This study demonstrates that, despite the fact that the handover is an identified EPA, our interns did not enter residency with the skillset required to successfully demonstrate the required key components of a written patient handover. This demonstrates an undergraduate curricular need for the newly identified EPA that must be addressed.

An enhanced fast handover triggering mechanism for Fast Proxy Mobile IPv6

Handover delay performance is a critical issue to support real-time applications in wireless networks. To address this issue, this paper presents an Enhanced fast handover Triggering Mechanism (ETM) to improve the handover performance of mobile nodes (MNs) in Fast Proxy Mobile IPv6 (FPMIPv6). Making use of the information from the link layer, the ETM predicts two cases that the MNs perform in the reactive handover mode. Then, it establishes the bi-directional tunnel in advance for fast handover. As a result, the reactive handover delay is significantly reduced. Integrating the ETM into FPMIPv6 forms an enhanced Fast Proxy Mobile IPv6 (eFPMIPv6) protocol. Simulation experiments show that with the presented ETM mechanism, the eFPMIPv6 outperforms the original FPMIPv6 in terms of the overall handover performance.

A novel geometric handover model for aerial 4G networks with WiFi‐based X2 interface

AbstractGiven the temporary nature of radio communications for mission critical scenarios, the existing dedicated public safety network lacks the flexibility of cutting edge technologies to leverage on packet data services. In this context, new challenges arise such as high‐capacity demand and low‐latency flexible backhaul connection for public safety users. In this paper, we consider a scenario in which 4G LTE radio coverage is provisioned by aerial eNodeBs installed on low‐altitude platforms raised in the sky and interconnected through WiFi links. We focus our attention on the critical aspect of theThird Generation Partnership Project handover mechanism studying the handover performance using a X2 interfaces over WiFi links. We develop a novel geometric model of the handover in the context of public safety communications but extensible also to other contexts. Relying on such a model, the handover failure probability is computed taking into account the different handover phases. The coverage area of an aerial eNodeB is studied using a suitable air‐to‐ground propagation model, while the average handover duration is computed taking into account the delay introduced by the WiFi communication dynamics. Copyright © 2016 John Wiley & Sons, Ltd.

Optimization of Vertical Handover Performance Using Elimination Based MCDM Algorithm

In heterogeneous networks environment, Vertical Handover Decision (VHD) algorithms help mobile terminals to choose the best network between all the available networks. VHD algorithms provide the QoS to a wide range of applications anywhere at any time. In this paper, a generic and novel solution to solve the Vertical Handover (VHO) problem has been developed. This solution contains two major subsystems: The first subsystem is called elimination system. Elimination system is received the different VHO criteria such as received signal strength, network load balancing and mobile station speed from the different available networks. After that, the inappropriate alternatives are eliminated based on the elimination conditions. The second subsystem is a Multiple Criteria Decision Making (MCDM) system that chooses the appropriate alternative from the remaining alternatives of the elimination phase. For simulate the proposed solution, MATLAB program is used with aid of MATLAB-based toolbox that is called RUdimentary Network Emulator (RUNE). The combination of both subsystems avoids the processing delay caused by unnecessary computation over available networks which do not ensure connection performance. Also it avoids increasing the number of unnecessary handovers, ping pong effect, blocking rate and dropping rate by reducing the handover failure rate. A performance analysis is done and results are compared to other reference algorithms. These results demonstrate a significant improvement over other reference algorithms in terms of handover failure rate, percentage of satisfied users, and percentage of the low cost network usage.

THE PERFORMANCE OF HANDOVER SCENARIO FOR MACROCELL AND FEMTOCELL IN LTE HETEROGENEOUS NETWORK

Seamless handover process between macrocell and femtocell base stations is a major challenge of LTE femtocell-macrocell integrated system because the need of an efficient handover which can transfer User Equipment (UE) between femtocell and macrocell. The challenge facing today and future is to provide seamless handover initiation scheme and better signal strength to users because of the different LTE heterogeneous network. So, the deployment of femtocells can offload traffic from the LTE macro cellular to be managed by the femto cellular network. This research presents the handover performance when the femtocells are deployed on the macrocell heterogeneous network and also LTE femtocell-macrocell integrated network scheme for hand-in and hand-out handover process. The simulation results show a significant reduction in number of handover calls rate with the proposed scheme which can manage overloaded traffic in the LTE heterogeneous network.

Optimization of Vertical Handover Performance Using Elimination Based MCDM Algorithm

In heterogeneous networks environment, Vertical Handover Decision (VHD) algorithms help mobile terminals to choose the best network between all the available networks. VHD algorithms provide the QoS to a wide range of applications anywhere at any time. In this paper, a generic and novel solution to solve the Vertical Handover (VHO) problem has been developed. This solution contains two major subsystems: The first subsystem is called elimination system. Elimination system is received the different VHO criteria such as received signal strength, network load balancing and mobile station speed from the different available networks. After that, the inappropriate alternatives are eliminated based on the elimination conditions. The second subsystem is a Multiple Criteria Decision Making (MCDM) system that chooses the appropriate alternative from the remaining alternatives of the elimination phase. For simulate the proposed solution, MATLAB program is used with aid of MATLAB-based toolbox that is called RUdimentary Network Emulator (RUNE). The combination of both subsystems avoids the processing delay caused by unnecessary computation over available networks which do not ensure connection performance. Also it avoids increasing the number of unnecessary handovers, ping pong effect, blocking rate and dropping rate by reducing the handover failure rate. A performance analysis is done and results are compared to other reference algorithms. These results demonstrate a significant improvement over other reference algorithms in terms of handover failure rate, percentage of satisfied users, and percentage of the low cost network usage.

RETRACTED ARTICLE: Improved fast handover method for multiple node by using mobile nodes guide

The fast mobile internet protocol version 6 (FMIPv6) was suggested as a fast handover mechanism over the mobile wireless Internets in order to reduce the handover latency of a mobile node (MN). However, FMIPv6 was originally designed to deal with single MN's. In mobile wireless Internet, a multiple MNs may do a handover at the same time as a consequence of its movement from one network to another new one. This will therefore lead to the bandwidth waste and low handover performance. This paper intends to propose a multiple handover-based mobile node (MHB-MN) control method and an enhanced FMIPv6 mechanism in order to resolve the abovementioned problem. The proposal of such an MHB-MN method aims at having one mobile node work as a guide for a group of neighboring MNs. This means that the guide of MN prepares itself for a handover before actually taking the initial steps of the actual handover operation. Based on obtained results, it is plainly observable that by MHB-MN method, the handover initiation time, handover latency and handover control messages can be reduced compared to those of FMIPv6. Furthermore, the contention of the wireless channel for multiple MNs can be improved by the use of fewer control messages. Finally, the paper introduces an analytical model to show that by enabling the MHB-MN method and enhancing the FMIPv6 method, a multiple of nodes can perform rapid handover processes with low handover latency compared to that of the FMIPv6 technique.

Fast handover solution for network-based distributed mobility management in intelligent transportation systems

The current IP mobility protocols are called centralized mobility management (CMM) solutions, in which all data traffic and management signaling messages must be forwarded to an anchor entity. In some vehicle scenarios, vehicles may move as a group from one roadside unit to another (i.e., after traffic lights or traffic jams). This causes data traffic and exchanged mobility messages to peak at the anchor entity and, consequently, affects the network performance. A new design paradigm aimed at addressing the anchor entity issue is called distributed mobility management (DMM); it is an IETF proposal that is still being actively discussed by the IETF DMM working group. Nevertheless, network-based DMM is designed based on the well-known network-based CMM protocol Proxy Mobile IPv6 (PMIPv6). There is no significant difference between network-based DMM and PMIPv6 in terms of handover latency and packet loss. Because vehicles change their roadside unit frequently in this context, the IP addresses of mobile users (MUs) require fast IP handover management to configure a new IP address without disrupting ongoing sessions. Thus, this paper proposes the Fast handover for network-based DMM (FDMM) based on the Fast Handover for PMIPv6 (PFMIPv6). Several modifications to PFMIPv6 are required to adapt this protocol to DMM. This paper specifies the necessary extensions to support the scenario in which an MU has old IP flows and hence has multiple anchor entities. In addition, the analytic expressions required to evaluate and compare the handover performance of the proposed FDMM and the IETF network-based DMM have been derived. The numerical results show that FDMM outperforms the IETF network-based DMM in terms of handover latency, session recovery and packet loss at the cost of some extra signaling.

Fuzzy layered physical cell identities assignment in heterogeneous and small cell networks

Massive irregular deployments of small cells require corresponding physical cell identities (PCIs) in heterogeneous cellular networks. The number of PCIs is restricted by the synchronisation sequence result in PCI reuse at an appropriate distance among base stations. Some methods of PCI assignment are given either globally optimal or completely preferential. Accordingly, the former cannot guarantee handover performance, and the latter may lead to low efficiency of allocations. A layered allocation algorithm based on fuzzy clustering is proposed. Simulation results show that it can improve the efficiency of the PCI assignment, while maintaining handover performance.

An Optimized and Distributed Data Packet Forwarding Scheme in LTE/LTE-A Networks

Long-term evolution (LTE)/LTE-advanced (LTE-A) networks have recently introduced a data packet forwarding scheme between evolved node Bs (eNBs) to reduce the signaling overhead and the delay incurred in the data path switching scheme, which is a baseline handover scheme in LTE/LTE-A networks. Even with the data packet forwarding scheme, if the length of the forwarding chain is set inappropriately, the data packet forwarding scheme suffers from the degraded throughput. To attain the optimal handover performance in terms of throughput and delay and reduce the signaling overhead, we propose an optimized and distributed data packet forwarding scheme where the optimal length of the forwarding chain is obtained by a Markov decision process (MDP). In addition, a low-complexity value iteration algorithm is devised to solve the optimality equation of MDP in a more practical manner. Real trace-driven evaluation results demonstrate that the proposed scheme determines the optimal length of the forwarding chain adaptively to the applications' quality-of-service (QoS) requirements and reduces the signaling overhead and delay while achieving higher throughput in diverse environments.

Sustainability of protocolized handover of pediatric cardiac surgery patients to the intensive care unit.

Transfer of patient care among clinicians (handovers) is a common source of medical errors. While the immediate efficacy of these initiatives is well documented, sustainability of practice changes that results in better processes of care is largely understudied. The objective of the current investigation was to evaluate the sustainability of a protocolized handover process in pediatric patients from the operating room after cardiac surgery to the intensive care unit. This was a prospective study with direct observation assessment of handover performance conducted in the cardiac ICU (CICU) of a free-standing, tertiary care children's hospital in the United States. Patient transitions from the operating room to the CICU, including the verbal handoff, were directly observed by a single independent observer in all phases of the study. A checklist of key elements identified errors classified as: (1) technical, (2) information omissions, and (3) realized errors. Total number of errors was compared across the different times of the study (preintervention, postintervention, and the current sustainability phase). A total of 119 handovers were studied: 41 preintervention, 38 postintervention, and 40 in the current sustainability phase. The median [Interquartile range (IQR)] number of technical errors was significantly reduced in the sustainability phase compared to the preintervention and postintervention phase, 2 (1-3), 6 (5-7), and 2.5 (2-4), respectively P = 0.0001. Similarly, the median (IQR) number of verbal information omissions was also significantly reduced in the sustainability phase compared to the preintervention and postintervention phases, 1 (1-1), 4 (3-5) and 2 (1-3), respectively. We demonstrate sustainability of an improved handover process using a checklist in children being transferred to the intensive care unit after cardiac surgery. Standardized handover processes can be a sustainable strategy to improve patient safety after pediatric cardiac surgery.

Analysis of Handover Trigger Scheme Based on Distance for LTE High-speed Railway Networks

In high-speed railway environment, frequent handovers and high handover failure probability result in serious communication interruptions and call drops, which become pressing problem to be solved. Alternative reference point based handover scheme can be an applicative solution for high-speed rail. This paper analyzes the impact of handover location on the handover performance. And numerical analysis is utilized to give a method to determine the distance from the serving eNodeB and the adjacent one to the mobile terminal when handover is triggered. Handover failure probability is used as criteria for performance. Simulation results show that the proposed scheme has a better performance than typical event based scheme in high speed environment.

Cognitive Cellular Networks: A Q-Learning Framework for Self-Organizing Networks

Self-organizing networks (SON) aim at simplifying network management (NM) and optimizing network capital and operational expenditure through automation. Most SON functions (SFs) are rule-based control structures, which evaluate metrics and decide actions based on a set of rules. These rigid structures are, however, very complex to design since rules must be derived for each SF in each possible scenario. In practice, rules only support generic behavior, which cannot respond to the specific scenarios in each network or cell. Moreover, SON coordination becomes very complicated with such varied control structures. In this paper, we propose to advance SON toward cognitive cellular networks (CCN) by adding cognition that enables the SFs to independently learn the required optimal configurations. We propose a generalized Q-learning framework for the CCN functions and show how the framework fits to a general SF control loop. We then apply this framework to two functions on mobility robustness optimization (MRO) and mobility load balancing (MLB). Our results show that the MRO function learns to optimize handover performance while the MLB function learns to distribute instantaneous load among cells.

Physical constraint and load aware seamless handover for IPTV in wireless LANs

In wireless LANs (WLANs), handover is usually performed based on either signal power or congestion level. However, considering only the congestion level could be insufficient for handover since it may cause traffic loss. Therefore, besides the load of access points (APs), it is necessary to consider the physical conditions of different WLANs for performing a seamless handover. This article introduces a novel scheme for seamless handover of IPTV streams in WLAN carrying IPTV traffic, called Physical Constraint and Load Aware (PCLA) handover. The PCLA can compute the load of APs for congestion detection purposes. In PCLA, a mobile node chooses the best network considering signal strength, bit error rate in the relevant environment, and the congestion of APs for making a seamless handover. The simulation results show the appropriateness of PCLA in improving handover performance.

Fuzzy Logic Based Decision Making Algorithm to Optimize the Handover Performance in HetNets

A prominent growth in a wireless communication system provides a wide range of services for a heterogeneous wireless network thus accomplishing user’s needs. These real time services are delay sensitive which requires a continuous internet connection. Assuring a seamless end-end connectivity without link outages at the mid of an action is a crucial ongoing problem. Thus the main objective relies on designing a cognitive algorithm to achieve the practical impossibility of having a sustainable net connection while roaming across various technologies. Hence, to fulfill this and degrade vertical handover (VHO) issues an enhanced fuzzy logic based algorithm is proposed. Further, it focuses on improving the transmission quality with low handover latency, less packet loss and reduced false handover. Along with this the algorithm achieves an accurate prediction in the decision making of an optimal network to which the idle node gets connected. The networking environment also has an efficient mobility management, where the functioning network controls the mobility of concerned mobile nodes. Finally the simulation process of this proposal on a comprehensive test-bed infers the fuzzy logic based algorithm, guaranteed seamless connection. Further, the system has a 1.6% improvement in reducing the handover delay and 1.3% in packet loss reduction than the existing approaches, which in turn improves the transmission quality.

Handover education improves skill and confidence.

Despite the frequency of patient-care handovers and vulnerability to errors, medical schools infrequently teach handover skills. Our study evaluated the impact of a medical school handover curriculum on students' performance, as rated by faculty members, peers and self-assessment. Nineteen fourth-year medical students participated in a handover curriculum that included a workshop and three directly observed patient handovers, with feedback from faculty members. Multivariate repeated-measures analysis evaluated faculty member, peer, and self-rated performance over time. Students' self-assessed confidence in performing handovers prior to, at the end of, and 8-12months after the curriculum was also analysed. Faculty member, peer and self-assessments showed that students' performance significantly improved after the curriculum, on handover content, clinical judgment and overall performance (p<0.05). Students rated the curriculum as effective and characterised themselves as more prepared to perform handovers, with these findings persisting for 8-12months (p≤0.001). Medical schools infrequently teach handover skills DISCUSSION: A handover curriculum appears to improve medical students' handover performance, as evaluated by independent ratings from faculty members, peers and the students themselves, in addition to improving the students' confidence.

Enhanced inter‐access service network handover authentication scheme for IEEE 802.16m network

The 802.16m mobile worldwide interoperability for microwave access (WiMAX) standard is the amendment to the 802.16e standard. It introduced high mobility features that enable mobile broadband services at vehicular speeds beyond 120 km/h. However, handover latency in mobile WiMAX may affect real-time application sessions such as VoIP at very high vehicle speed. This makes it imperative to develop fast and secure handover schemes for such very high-speed vehicles. One of the main factors that affect handover performance in 802.16m standard is the delay introduced by the authentication procedure when a mobile user moves between base stations (BSs). In this study, a recently proposed intra-access service network (ASN) handover authentication scheme with privacy preservation is extended to a fast symmetrical key inter-ASN handover authentication scheme that avoids the involvement of third party. The proposed scheme solves the pairwise master key backward and forward security problems and provides mutual authentication between the mobile station (MS) and the target BS during inter-ASN handover event. Finally, the proposed scheme provides MS anonymity and reduces the need to a high-quality tamper-proof device in the BS that was required in the previous scheme.

Performance Evaluation of Handover in WiMax with TCP and UDP as Underlying Protocol

The rejection of an ongoing connection/session is serious problem and it degrades the QoS and efficiency of the network rather than rejecting a request for new connection. The impact on performance of handovers is a serious problem in cellular systems that must be addressed. During handover there may be delay in packets and connections may drop. Real time applications i.e., VoIP and streaming video can be adversely affected by such kind of delays. In this study we used TCP and UDP as an underlying protocol for exchange of data between two wireless mobile nodes in a WiMax access network and had evaluated the effect on performance in terms of end-to-end delay and throughput. The results showed that when handover is triggered the transfer window resets to zero causing higher throughput and end-to-end delay for TCP than UDP based on packet size and traffic load.