Handover Mechanism Research Articles

Achieving Efficient and Secure Handover in LEO Constellation-Assisted Beyond 5G Networks

Ubiquitous connection to modern vehicles is mandatory to support diverse intelligent functions, including autonomous driving, telediagnosis, infotainment services, and others. Since the deployment of the cellular access points is still scarce in rural areas, the low earth orbit (LEO) constellation-based communication is believed to provide a realistic alternative. However, due to the long propagation delay and limited satellite on-board processing ability, the design of security protocols in LEO constellations remain challenging. Aiming at these challenges, we propose a secure user access and inter-satellite handover mechanism, which achieves the control- and user-plane key separation. Specifically, our proposed scheme exploits an identity-based encryption scheme with proxy re-encryption to achieve the key establishments with high efficiency, and it also achieves the highly efficient secure batch handover with the assistance of a stack. Detailed analysis is performed to demonstrate the security properties of our proposed scheme, in terms of confidentiality, authentication, and forward/backward key separation. Furthermore, simulation results illustrate that our proposed scheme achieves high computational complexity and communication overheads in comparison with a traditional scheme.

An efficient anonymous group handover authentication protocol for MTC devices for 5G networks

Machine Type Communication (MTC) has been emerging for a wide range of applications and services for the Internet of Things (IoT). In some scenarios, a large group of MTC devices (MTCDs) may enter the communication coverage of a new target base station simultaneously. However, the current handover mechanism specified by the Third Generation Partnership Project (3GPP) incur high signalling overhead over the access network and the core network for such scenario. Moreover, other existing solutions have several security problems in terms of failure of key forward secrecy (KFS) and lack of mutual authentication. In this paper, we propose an efficient authentication protocol for a group of MTCDs in all handover scenarios. By the proposal, the messages of two MTCDs are concatenated and sent by an authenticated group member to reduce the signalling cost. The proposed protocol has been analysed on its security functionality to show its ability to preserve user privacy and resist from major typical malicious attacks. It can be expected that the proposed scheme is applicable to all kinds of group mobility scenarios such as a platoon of vehicles or a high-speed train. The performance evaluation demonstrates that the proposed protocol is efficient in terms of computational and signalling cost.

Design and Implementation of Mobility Management for Indoor Beam-Steered Infrared Light Communication System

This work describes a beam-steered infrared light communication (BS-ILC) system that facilitates non-shared and ultra-high data rate communications to individual user devices. The BS-ILC system comprises optical antennas, vision-based user localization, and optical receivers (each having a wide field-of-view photodetector and an IR-LED tag). Because of deploying narrow optical beams, the BS-ILC system requires efficient mobility management to support mobile user devices. This study develops a new BS-ILC model based on the Gaussian beam propagation that precisely estimates the user device's received signal strength from its localized position. Then, we propose mobility management consisting of two main components as location management and handover management. We further analyze the handover rate and the ping-pong effect to design the most efficient and robust handover mechanisms. Numerical and experimental results illustrate that the proposed mobility management can realize the seamless transmission, enabling >10 Gbit/s link per user.

Session Duration Between Handovers in Dense LEO Satellite Networks

Low Earth Orbit (LEO) constellations offer superior low latency performance and excellent signal power, however because of satellites inherent fast relative movement, frequent handovers are necessary for maintaining a continuous connection in such constellations. This letter lays an analytic method for estimating the session duration between two consecutive handovers which is an important design parameter that impacts the overall network performance. We focus on recent LEO networks where, due to their high density, it is possible to analytically capture the bounds of their performance using tractable tools from stochastic geometry. The letter studies two possible physical handover mechanisms and compares the analytic results with well-design practical network deployments.

A Novel Handover Mechanism of PMIPv6 for the Support of Multi-Homing Based on Virtual Interface

The Proxy Mobile IPv6 (PMIPv6) is a network-based accessibility managing protocol. Because of PMIPv6’s network-based approach, it accumulates the following additional benefits, such as discovery, efficiency. Nonetheless, PMIPv6 has inadequate sustenance for multi-homing mechanisms, since every mobility session must be handled through a different binding cache entry (BCE) at a local mobility anchor (LMA) according to the PMIPv6 specification, and thus PMIPv6 merely permits concurrent admittance for the mobile node (MN) which is present in the multi-homing concept. Consequently, when a multi-homed MN interface is detached from its admittance network, the LMA removes its moving part from the BCE, and the current flows connected with the apart interface are not transmitted to the multi-homed MN, even if a more multi-homed MN interface is still linked to another access network. A superior multi-homing support proposal is proposed to afford flawless mobility among the interfaces for a multi-homed MN to address this problem. The projected method can shift an application from a disconnected interface of a multi-home MN to an attached interface using the PMIPv6 fields of Auxiliary Advertisement of Neighbor Detection (AAND).

Performance assessment of VoIP service over different handover mechanisms in UMTS networks

Many researchers have discussed various topics in universal mobile telecommunication system (UMTS) networks: the process of switching from one cell to another for the subscriber and the impact of the quality of the connection during the transition process, quality of services (QoS), the quality of the uplink and downlink carrier line, the various types of code for the voice transmitted through the Internet, especially the research that discussed voice over internet protocol (VoIP) technology as voice travels from cell to cell in mobile networks, depending on the type of delivery. In this paper, a proposed scenario of a UMTS network was implemented to evaluate the multicellular VoIP movement; the proposed UMTS network was simulated using the OPNET 14.5 simulator. The calculation and analysis of the different parameters of the user while moving from one cell to another with different movement speeds considered, the best mean opinion score (MOS) value (3.19) registered for the scenario (soft handover) comparing with another type of handover (3.00).

Efficient Mobility Management for Indoor Optical Wireless Communication System

Beam-steered infrared light communication (BS-ILC) is a promising technology to establish high data rate links for next-generation indoor optical wireless networks. However, practical limitations such as localization latency and handover delay make challenging to implement a reliable BS-ILC system for mobile user devices. This letter studies mobility management, enabling the user devices to stay connected while they are on the move. Our BS-ILC system uses a wavelength domain where each wavelength covers one wireless cell. A camera-based localization determines the position of user devices relative to access points. With the help of a prediction algorithm, we demonstrated real-time localization with a <; 4mm tracking error. Furthermore, we propose and evaluate experimentally hard and soft handover mechanisms to support inter-cell user mobility. This is the first demonstration of seamless transmission in a BS-ILC system to the best of our knowledge.

Modeling of Wireless Traffic Load in Next Generation Wireless Networks

Software defined WiFi network (SD-WiFi) is a new paradigm that addresses issues such as mobility management, load management, route policies, link discovery, and access selection in traditional WiFi networks. Due to the rapid growth of wireless devices, uneven load distribution among the network resources still remains a challenging issue in SD-WiFi. In this paper, we design a novel four-tier software defined WiFi edge architecture (FT-SDWE) to manage load imbalance through an improved handover mechanism, enhanced authentication technique, and upgraded migration approach. In the first tier, the handover mechanism is improved by using a simple AND operator and by shifting the association control to WAPs. Unauthorized user load is mitigated in the second tier, with the help of base stations (BSs) which act as edge nodes (ENs), using elliptic ElGamal digital signature algorithm (EEDSA). In the third tier, the load is balanced in the data plane among the OpenFlow enabled switches by using the whale optimization algorithm (WOA). Moreover, the load in the fourth tier is balanced among the multiple controllers. The global controller (GC) predicts the load states of local controllers (LCs) from the Markov chain model (MCM) and allocates packets to LCs for processing through a binary search tree (BST). The performance evaluation of FT-SDWE is demonstrated using extensive OMNeT++ simulations. The proposed framework shows effectiveness in terms of bandwidth, jitter, response time, throughput, and migration time in comparison to SD-WiFi, EASM, GAME-SM, and load information strategy schemes.

Using an Efficient Technique Based on Dynamic Learning Period for Improving Delay in AI-Based Handover

The future high-speed cellular networks require efficient and high-speed handover mechanisms. However, the traditional cellular handovers are based upon measurements of target cell radio strength which requires frequent measurement gaps. During these measurement windows, data transmission ceases each time, while target bearings are measured causing serious performance degradation. Therefore, prediction-based handover techniques are preferred in order to eliminate frequent measurement windows. Thus, this work proposes an ultrafast and efficient XGBoost-based predictive handover technique for next generation mobile communications. The ML algorithm in general prefers 70–30% of training and test data, respectively. However, always obtaining 70% of training samples in mobile communications is challenging because the channel remains correlated within coherence time only. Therefore, collecting training samples beyond coherence time limits performance and adds delay; thus, the proposed work trains the model within coherence time where this fixed data split of 70–30% makes the model exceed coherence time. Despite the fact that the proposed model gets starved of required training samples, still there is no loss in predication accuracy. The test results show a maximum delay improvement of up to 596 ms with enhanced performance efficiency of 68.70% depending upon the scenario. The proposed model reduces delay and improves efficiency by having an appropriate training period; thus, the intelligent technique activates faster with improved accuracy and eliminates delay in the algorithm to predict mmWaves’ signal strength in contrast to actually measuring them.

A survey on various handover technologies in 5G network using the modular handover modules

PurposeFifth-generation (5G) networks play a significant role in handover methods. 5G wireless network is open, flexible and highly heterogeneous along with the overlay coverage and small cell deployments. Handover management is one of the main problems in the heterogeneous network. Also, handover satisfies the needs of ultra-reliable communications along with very high reliability and availability in 5G networks. Handover management deals with every active connection of a user’s device, which moves the connection between the user’s device and the counterparty from one network point to another. Thus, the handover decision determines the best access network and also decides whether the handover is performed or not.Design/methodology/approachThe main intention of this survey is to review several existing handover technologies in 5G. Using the categories of analysis, the existing techniques are divided into different techniques such as authentication-based techniques, blockchain-based techniques, software-defined-based techniques and radio access-based techniques. The survey is made by considering the methods such as used software, categorization of methods and used in the research works. Furthermore, the handover rate is considered for performance evaluation for the handover techniques in 5G. The drawbacks present in the existing review papers are elaborated in research gaps and issues division.FindingsThrough the detailed analysis and discussion, it can be summarized that the widely concerned evaluation metric for the performance evaluation is the handover rate. It is exploited that the handover rate within the range of 91%–99% is achieved by three research papers.Originality/valueA survey on the various handover mechanisms in 5G networks is expected in this study. The research papers used in this survey are gathered from different sources such as Google Scholar and IEEE. Also, this survey suggests a further extension for the handover mechanism in 5G networks by considering various research gaps and issues.

Design and development of handover simulator model in 5G cellular network

In the modern era of technology, the high speed internet is the most important part of human life. The current available network is reckoned to be slow in speed and not be up to snuff for data transmission regarding business applications. The objective of handover mechanism is to reassign the current session handle by internet gadget. The globe needs the next generation high mobility and throughput performance based internet model. This research paper explains the proposed method of design and development for handover based 5G cellular network. In comparison to the traditional method, we propose to control the handovers between base-stations using a concentric method. The channel simulator is applied over the range of the frequencies from 500 MHz to 150 GHz and radio frequency for the 700 MHz bandwidth. The performance of the simulation system is calculated on the basis of handover preparation and completion time regarding base station as well as number of users. From this experiment we achieve the 7.08 ms handover preparation time and 9.98 ms handover completion time. The author recommended the minimum handover completion time, perform the high speed for 5G cellular networks.

Molecular mechanism of cargo recognition and handover by the mammalian signal recognition particle.

SUMMARYCo-translational protein targeting to membranes by the signal recognition particle (SRP) is a universally conserved pathway from bacteria to humans. In mammals, SRP and its receptor (SR) have many additional RNA features and protein components compared to the bacterial system, which were recently shown to play regulatory roles. Due to its complexity, the mammalian SRP targeting process is mechanistically not well understood. In particular, it is not clear how SRP recognizes translating ribosomes with exposed signal sequences and how the GTPase activity of SRP and SR is regulated. Here, we present electron cryo-microscopy structures of SRP and SRP·SR in complex with the translating ribosome. The structures reveal the specific molecular interactions between SRP and the emerging signal sequence and the elements that regulate GTPase activity of SRP·SR. Our results suggest the molecular mechanism of how eukaryote-specific elements regulate the early and late stages of SRP-dependent protein targeting.

Deployment of Robust Security Scheme in SDN Based 5G Network over NFV Enabled Cloud Environment

In this Modern era, Software Defined Network (SDN), Network Function Virtualization (NFV), and cloud computing participating of Fifth Generation (5G) network emergence. This paper presents a robust security scheme to provide fortification against major threats along with user privacy in 5G network, two additional entities are introduced. For mobile users, initial authentication is provided at access points by an inventive Highly Secured Authentication and Handover Mechanism (HS-AOHM) scheme which minimizes handover latency without loss of user privacy. Then the authorized user packets are arrived at dispatcher in which a novel Tree Based Switch Assignment (TBSA) algorithm is incorporated. TBSA mitigates the flow table overloading attack by assigning packets to underloaded switches. In controller, DDoS attack is detected with the assist of entropy analysis. Then the suspicious packets are redirected to scrubbing Virtual Network Function (sVNF) in cloud. In sVNF, suspicious packets are classified into normal packets and malicious packets by using Hybrid Fuzzy with Artificial Neural Network (HF-ANN) classifier based on packet features. Normal packets are allowed to access applications whereas malicious packets are dropped at sVNF. Extensive simulation shows security improvement in 5G network in terms of handover latency, holding time, switch failure rate, detection accuracy, and delay.

Automatic handover execution technique using machine learning algorithm for heterogeneous wireless networks

Integrating LTE sub-6 GHz and millimeter wave (mmWave) bands brings great benefit in increasing communication bandwidth, reliability, and better coverage of future smart intelligent network and its applications. However, finding the right mmWave remote radio units (RRUs) is challenging due to coverage blindness of directional beams. Further, the mmWave network depends on edge cloud deployment for satisfying low latency requirement of future smart applications. Along with, reducing energy consumption for handover execution is important due to the battery constraint of IoT (Internet of Things) device. Thus, it is important to reduce the signaling overhead of the handover process. First, this paper presents an efficient handover mechanism between LTE and mmWave; second present automatic handover execution mechanism between LTE and mmWave using a machine learning algorithm. Third presented improved XGBoost classification algorithm for predicting handover success rate using channel information collected through sampling window. Lastly, showed combining machine learning prediction model with standard handover execution model reduces signaling overhead and improves the handover success rate. The experiment is conducted by varying IoT device the result achieved shows XGBoost-based handover execution model achieves much superior performance than existing KNN-based handover execution algorithm.

Are You Still Working on This? An Empirical Study on Pull Request Abandonment

The great success of numerous community-based open source software (OSS) is based on volunteers continuously submitting contributions, but ensuring sustainability is a persistent challenge in OSS communities. Although the motivations behind and barriers to OSS contributors’ joining and retention have been extensively studied, the impacts of, reasons for and solutions to contribution abandonment at the individual level have not been well studied, especially for pull-based development. To bridge this gap, we present an empirical study on pull request abandonment based on a sizable dataset. We manually examine 321 abandoned pull requests on GitHub and then quantify the manual observations by surveying 710 OSS developers. We find that while the lack of integrators’ responsiveness and the lack of contributors’ time and interest remain the main reasons that deter contributors from participation, limitations during the processes of patch updating and consensus reaching can also cause abandonment. We also show the significant impacts of pull request abandonment on project management and maintenance. Moreover, we elucidate the strategies used by project integrators to cope with abandoned pull requests and highlight the need for a practical handover mechanism. We discuss the actionable suggestions and implications for OSS practitioners and tool builders, which can help to upgrade the infrastructure and optimize the mechanisms of OSS communities.

Mobility-Aware Seamless Handover With MPTCP in Software-Defined HetNets

In this article, the problem of vertical handover in software-defined network (SDN) based heterogeneous networks (HetNets) is studied. In the studied model, HetNets are required to offer diverse services for mobile users. Using an SDN controller, HetNets have the capability of managing users' access and mobility issues but still have the problems of ping-pong effect and service interruption during vertical handover. To solve these problems, a mobility-aware seamless handover method based on multipath transmission control protocol (MPTCP) is proposed. The proposed handover method is executed in the controller of the software-defined HetNets (SDHetNets) and consists of three steps: location prediction, network selection, and handover execution. In particular, the method first predicts the user's location in the next moment with an echo state network (ESN). Given the predicted location, the SDHetNet controller can determine the candidate network set for the handover to pre-allocate network wireless resources. Second, the target network is selected through fuzzy analytic hierarchical process (FAHP) algorithm, jointly considering user preferences, service requirements, network attributes, and user mobility patterns. Then, seamless handover is realized through the proposed MPTCP-based handover mechanism. Simulations using real-world user trajectory data from Korea Advanced Institute of Science & Technology show that the proposed method can reduce the handover times by 10.85% to 29.12% compared with traditional methods. The proposed method also maintains at least one MPTCP subflow connected during the handover process and achieves a seamless handover.

MobTHE (Mobile Temperature Heterogeneity Energy) Aware Routing Protocol for WBAN IoT Health Application

In this paper, we are proposing and validating “mobTHE” protocol that is designed to fill the gap in handling seamless mobile communication for on-body nodes. Therefore, “mobTHE” protocol tackles the dis-connectivity problem resulted from the sensor nodes' mobility while keeping an eye on the network's sustainability in terms of maximum packet throughput, prolonged node lifetime, and low temperature. To provide such a balanced trade-off, we utilize two Coordinator Nodes (CNs), namely, CN1 and CN2. Both of these CNs are working as Serving CN (SCN) to its closest nodes and as Neighbour CN (NCN) to the sensor nodes located far from these CNs, which enable collecting data from different sensor nodes continuously. The challenge here is the synchronization between the two CNs in such a way to optimize network resources via minimizing packet transmission duplication and packet drop rate, which is the main contribution of this paper. We present a novel Handover (HO) mechanism during the sensor node mobility and changing between the two CNs. That HO mechanism is capable of minimizing the redundancy of packets and leading to minimization in the packet drop rate. Considering the worst-case scenario where the sensor node is out of the two CNs range, we exploit two-hops data transmission. Parent Node (PN) is selected “on demand” to carry only the data of the moving node which moves away from both CNs rather than carrying the data of all sensor nodes which conserves the energy of the PN nodes as well as the moving node. The simulation analysis depicted that “mobTHE” protocol outperforms the conventional “THE” and “iM-SIMPLE” protocols in terms of temperature control, WBAN lifetime, throughput, and overall residual energy.

Deep Reinforcement Learning-Based Adaptive Handover Mechanism for VLC in a Hybrid 6G Network Architecture

Visible light communication (VLC) is considered an important complementary technology for extremely high sixth-generation (6G) data transmission and has become part of a hybrid 6G indoor network architecture with an ultradense deployment of VLC access points (APs) that presents severe challenges to user mobility. An adaptive handover mechanism, which includes a seamless handover protocol and a selection algorithm optimized with a deep reinforcement learning (DRL) method, is proposed to overcome these challenges. Experimental simulation results reveal that the average downlink data rate with the proposed algorithm is up to 48% better than those with traditional RL algorithms and that this algorithm also outperforms the deep Q-network (DQN), Sarsa and Q-learning algorithms by 8%, 13% and 13%, respectively.

Clustering-cum-Handover Management Scheme for improved Internet access in high-density mobile wireless environments

The accessibility of ubiquitous communication services from various wireless technologies has become essential in the current Internet of everything (IoE) era. It is crucial for mobile users residing in densely populated areas to get the provision of uninterrupted connectivity and seamless services. To this end, this paper provides a mechanism for uninterrupted connectivity to a maximum number of users with the available resources. We propose a master/slave model in a 4G-Wi-Fi integrated network. Our novel Clustering-cum-Handover Management Scheme (CHMS) for dynamic cluster management together with the handover management in high density mobile wireless environment dispenses the unrestricted movement without connectivity loss and quality sacrifice. The dynamically configured clustering protocol of CHMS provides reduced cluster formation overhead and balances the load between cluster heads. To make smart selections, a distance-based energy-efficient clustering scheme is proposed for calculating the chances of a mobile device to become a cluster head. The seamless handover mechanism of CHMS manages the mobility of both the cluster head and cluster member while considering the limited energy of devices. It also achieves high network throughput and reduced end-to-end delay during handovers. Furthermore, our evaluation shows that CHMS provides application-specific quality of service even in highly dense wireless environments.

Supervised ensemble sentiment-based framework to measure chatbot quality of services

Developing an intelligent chatbot has evolved in the last few years to become a trending topic in the area of computer science. However, a chatbot often fails to understand the user’s intent, which can lead to the generation of inappropriate responses that cause dialogue breakdown and user dissatisfaction. Detecting the dialogue breakdown is essential to improve the performance of the chatbot and increase user satisfaction. Recent approaches have focused on modeling conversation breakdown using serveral approaches, including supervised and unsupervised approaches. Unsupervised approach relay heavy datasets, which make it challenging to apply it to the breakdown task. Another challenge facing predicting breakdown in conversation is the bias of human annotation for the dataset and the handling process for the breakdown. To tackle this challenge, we have developed a supervised ensemble automated approach that measures Chatbot Quality of Service (CQoS) based on dialogue breakdown. The proposed approach is able to label the datasets based on sentiment considering the context of the conversion to predict the breakdown. In this paper we aim to detect the affect of sentiment change of each speaker in a conversation. Furthermore, we use the supervised ensemble model to measure the CQoS based on breakdown. Then we handle this problem by using a hand-over mechanism that transfers the user to a live agent. Based on this idea, we perform several experiments across several datasets and state-of-the-art models, and we find that using sentiment as a trigger for breakdown outperforms human annotation. Overall, we infer that knowledge acquired from the supervised ensemble model can indeed help to measure CQoS based on detecting the breakdown in conversation.