Vertical Handover Decision Research Articles

Enhanced Handover Decision Algorithm in Heterogeneous Wireless Network.

Transferring a huge amount of data between different network locations over the network links depends on the network’s traffic capacity and data rate. Traditionally, a mobile device may be moved to achieve the operations of vertical handover, considering only one criterion, that is the Received Signal Strength (RSS). The use of a single criterion may cause service interruption, an unbalanced network load and an inefficient vertical handover. In this paper, we propose an enhanced vertical handover decision algorithm based on multiple criteria in the heterogeneous wireless network. The algorithm consists of three technology interfaces: Long-Term Evolution (LTE), Worldwide interoperability for Microwave Access (WiMAX) and Wireless Local Area Network (WLAN). It also employs three types of vertical handover decision algorithms: equal priority, mobile priority and network priority. The simulation results illustrate that the three types of decision algorithms outperform the traditional network decision algorithm in terms of handover number probability and the handover failure probability. In addition, it is noticed that the network priority handover decision algorithm produces better results compared to the equal priority and the mobile priority handover decision algorithm. Finally, the simulation results are validated by the analytical model.

VERTICAL HANDOVER DECISION MANAGEMENT ON THE BASIS OF SEVERAL CRITERIA FOR LVQNN WITH UBIQUITOUS WIRELESS NETWORKS

Vertical handover decision management is an essential to keep the seamless ubiquitous heterogeneous wireless networks since each access network has different operations in the next generation. In this paper, WCDMA, LTE and WLAN are cooperated in the architecture of mobile IP regional registration (MIP-RR). We propose the Learning Vector Quantization Neural Networks (LVQNNs) approach in order to maintain uninterrupted communication that depends on received signal strength indicator, data rate requirement, monetary cost of service and mobile terminal device speed metrics are considered as multi-criteria to initial handover. Furthermore, the multi-criteria are dynamic to influence for real-time and non-real time services in different networks and the users select the optimal target network which is the highest handover factor score in order to balance against the network condition and user preference. To ensure the Always Best Connected (ABC) demands, the simulation results illustrate that our proposed algorithm provided outperform the performance in term of unnecessary handover, the call dropping probability, data packet delay and network utilization compared with conventional method as fuzzy logic and neural network based machine learning.

Vertical Handover Decision Algorithm for Multimedia Streaming in VANET

Vehicular ad hoc networks represent one of the most important applications of wireless ad hoc networks. In highways, where different networks exist, frequent and sometimes unnecessary switches from one network to another may occur, which degrade network performance and affect applications, especially those that require high quality networks such as multimedia applications (Video conferencing, Video On-Demand, etc.). This work presents an analytical model and a Vertical Handover decision method for Highways called VHH. It is based on position, velocity, jitter, and density as mandatory inputs which aim to both minimize Vertical handover frequency and avoid unnecessary handoffs and ping pong effect between different networks, in the goal of enhancing multimedia streaming services in highways. A simulation is provided to prove the performance of the algorithm.

User-Driven Network Selection during Vertical Handover in 4G Networks

The importance of network selection for wireless networks, is to facilitate users with various personal wireless devices to access their desired services via a range of available radio access networks. The inability of these networks to provide broadband data service applications to users poses a serious challenge in the wireless environment. Network Optimization has therefore become necessary, so as to accommodate the increasing number of users’ service application demands while maintaining the required quality of services. To achieve that, the need to incorporate intelligent and fast mechanism as a solution to select the best value network for the user arises. This paper provides an intelligent network selection strategy based on the user- and network-valued metrics to suit their preferences when communicating in multi-access environment. A user-driven network selection strategy that employs Multi-Access Service Selection Vertical Handover Decision Algorithm (MASS-VHDA) via three interfaces; Wi-Fi, WiMAX and LTE-A is proposed, numerically evaluated and simulated. The results from the performance analysis demonstrate some improvement in the QoS and network blocking probability to satisfy user application requests for multiple simultaneous services.

Performance Analysis of Multi-level Vertical Handover in Wireless Heterogeneous Networks

The quest for high data rates, mobility and QoS has witness the integration of diverse wireless network systems in providing services to mobile users anywhere and at all-time. The convergence of these networks makes it possible for the mobile user equipment to roam seamlessly across the heterogeneous networks with session continuity. However, the integration comes with its own difficulties of selecting the right target network to handover to and therefore requires the right decision to achieve such task. This paper attempts to describe multi-level vertical handover decision algorithm that employs multi-attribute decision making in selecting the best network to optimize the VHO. The algorithm considers received signal sensitivity (power level or RSS), bandwidth and cost as the deciding factors in selecting the correct network based on the established memberships (function and degree) of the processed correlated weight vector. The results of the simulation show how the vertical handover optimization could be realized by selected the right target network.

Fuzzy based multi-criteria vertical handover decision modeling in heterogeneous wireless networks

Vertical handover gain significant importance due to the enhancements in mobility models by the Fourth Generation (4G) technologies. However, these enhancements are limited to specific scenarios and hence do not provide support for generic mobility. Similarly, various schemes are proposed based on these mobility models but most of them are suffered from the high packet loss, frequent handovers, too early and late handovers, inappropriate network selection, etc. To address these challenges, a generic vertical handover management scheme for heterogeneous wireless networks is proposed in this article. The proposed scheme works in three phases. In the first phase, a handover triggering approach is designed to identify the appropriate place for initiating handover based on the estimated coverage area of a WLAN access point or cellular base station. In the second phase, fuzzy rule based system is designed to eliminate the inappropriate networks before deciding an optimal network for handover. In the third phase, a network selection scheme is developed based on the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) decision mechanism. Various parameters such as delay, jitter, Bit Error Rate (BER), packet loss, communication cost, response time, and network load are considered for selecting an optimal network. The proposed scheme is tested in a mobility scenario with different speeds of a mobile node ranging from very low to very high. The simulation results are compared with the existing decision models used for network selection and handover triggering approaches. The proposed scheme outperforms these schemes in terms of energy consumption, handover delay and time, packet loss, good put, etc.

Improved vertical handover decision algorithm using ants' colonies with adaptive pheromone evaporation rate for 4th generation heterogeneous wireless networks

ACOR (Ant Colony Optimisation for Continuous Domains) has been proved to be able to adapt to vertical handoff mechanism. Adaptation capabilities of ACO are due to the pheromone evaporation, where the rate is usually fixed as it is done for vertical handover decision algorithm using ant colonies for 4G heterogeneous wireless networks. An adaptive pheromone evaporation rate (PER) is more suitable. High PER will eliminate the high intensity of pheromone trails that represent bad solutions from previous environments, while low PER may be more interesting when we have stagnation behaviours to minimise power consumption. In this paper, an update version of vertical handover decision algorithm using ant colonies for 4G heterogeneous wireless networks is proposed to vary the evaporation rate at different stages of the optimisation process. Simulation results show that ACOR with adaptive pheromone evaporation rate (ACOR APER) achieves promising results, when compared to the original ACOR and ACOR LPER (ACOR with low pheromone evaporation rate) with a fixed pheromone evaporation rate.

Vertical handover decision algorithm in heterogeneous wireless networks

With the recent progress in the area of cellular communication the issue of inter cells handover without dropping an ongoing connection with the base station has arisen. In this paper, the focus is on the performance of vertical handover. Various proposed interconnection architectures for vertical handover in heterogeneous networks were studied. Two different algorithms to make the decision on when and to which network perform a handover were considered. In the first of them the decision is based on the received signal strength (RSS). In the second one a fuzzy logic system that uses RSS, bandwidth, battery power and packet loss as the input parameters is proposed. The simulation results show that the algorithm based on fuzzy logic leads to a reduction of the number of handovers and a minimisation of the power consumption as compared to the first algorithm used here and the existing algorithms.

Vertical handover decision algorithm in heterogeneous wireless networks

Vertical handover decision algorithm in heterogeneous wireless networks

An Overview on ANS Methods: Who Is a Dominant for the Seamless Vertical Handover Decision through Heterogeneous Networks

An Overview on ANS Methods: Who Is a Dominant for the Seamless Vertical Handover Decision through Heterogeneous Networks

ANDSF-Assisted vertical handover decisions in the IEEE 802.11/LTE-Advanced network

To address the challenging issues of energy-efficiency and seamless connectivity in heterogeneous networks, 3GPP and IEEE have recently incorporated several architectural and functional enhancements to the baseline operation of their standards for cellular and wireless local area network access, respectively. Based on the 3GPP Access Network Discovery and Selection Function (ANDSF) as well as the advanced measurement capabilities provided by the IEEE 802.11-2012 and the 3GPP Long Term Evolution–Advanced (LTE-A) Standards, we propose an ANDSF-assisted energy-efficient vertical handover decision algorithm for the heterogeneous IEEE 802.11-2012 / LTE-A network. The proposed algorithm enables multi-mode mobile terminals to select and associate with the network point of attachment that minimizes the average overall power consumption at the mobile terminal and guarantees a minimum supported quality of service for its ongoing connections. System-level simulations demonstrate the performance of the proposed algorithm and compare it against that of other competing solutions.

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.

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.

Developing an Efficient Utility Theory based VHO Algorithm to Boost User Satisfaction in HETNETs

Objectives: Heterogeneous environment is formed by co-existing interworking networks, with the objective of providing mobile users with best connectivity at anytime. This is facilitated by handover process. In this paper we have proposed Utility Theory based vertical handover decision algorithm, taking into consideration utility functions/parameters like bandwidth, monetary cost, security and power consumption levels of candidate network available for handover. Methods/ Analysis: The proposed algorithm uses hybrid of Fuzzy logics and AHP to assign weights to the parameters and since the algorithm is utility based, the network are ranked using simple weighted sum of the parameters. Findings: The proposed algorithm selects the network which satisfies all the network selection criteria. Higher the level of user satisfaction served by the network, more it is suitable for handover in heterogeneous environment. Conclusion/Applications: The proposed algorithm provides higher level of user satisfaction. It is well suited for random and imprecise wireless environment since it makes use of fuzzy logics instead of crisp values. Furthermore to check its applicability in real time the proposed algorithm can be implemented on a simulation tool.

Handover Optimization Based on Media Independent Handover in New Networks NGWN

One of the challenging issues in Next Generation Wireless Network (NGWN) is achieving seamless Vertical Handover (VHO) while roaming between different technologies such as Wireless Fidelity (Wi- Fi), Worldwide Interoperability for Microwave Access (WiMAX), Universal Mobile Telecommunications System (UMTS) and Long Term Evolution (LTE). F or that the telecommunication operators will be required to develop a strategy for interoperability of these different types of existing network to give the best connection anywhere anytime for the Mobile Users (MUs). To full these requirements we propose a new VHO approach that based on loose coupling internetworking in conjunction with Mobile IPv4 ( MIPv4) under Media Independent Handover (MIH). Our objective is develop a strategy for interoperability of different technologies and optimized the VHO decision. Our proposed approach provides more exhaustive, high accurate and better performance compared with the approaches proposed in the literature.

Survey on Evaluation Models of Vertical Handoff Decision Algorithms

Heterogeneous systems, Vertical Handoff calculations (VHAs) used to permit mobile terminals (MT) to keep up the system association when versatile hub switch starting with one remote system then onto the next one. The Vertical Handover Decision is NP-Hard issue, thus assessment of all VHA is imperative perspective while working with Vertical Handoff calculations. In this paper, we concentrated on different assessment models which were utilized by past analysts. We likewise concentrated on the different parameters which are imperative for execution examination of VHAs and represent the absence of a legitimate assessment model to look at the different Vertical Handoff Algorithms (VHAs) that have been proposed in the writing.

Enhanced VHD Making Algorithm for 4G Heterogeneous Networks

In next generation wireless system such as Long Term Evolution (LTE) and Worldwide Interoperability Microwave Access (WIMAX) the major issue is to maintain the quality of service of a network. User required always best connected services anytime and anywhere. Due to increase in number of user on particular network, load is increased on a network. Due to high load handover is required but in many situations unnecessary handoff and handoff failure is initiated, which lags the performance of a network. To overcome this problem we have used RSS vertical handover decision method with some additional parameters to improve the performance in 4G heterogeneous networks.

Optimized RSS based Algorithm for Heterogeneous Networks

In next generation wireless system such as long term evolution (LTE) and worldwide interoperability microwave access (WIMAX) the major issue is to maintain the quality of service of a network. User required always best connected services anytime and anywhere. Due to increase in number of user on particular network, load is increased on a network. Due to high load handover is required but in many situations unnecessary handoff and handoff failure is initiated, which lags the performance of a network. To overcome this problem we have used RSS vertical handover decision method with some additional parameters to improve the performance in 4G heterogeneous networks.

Hybrid Particle Swarm Optimization based Vertical Handoff Decision Algorithm for Multicriteria Metrics for Radio Heterogeneous Network

One among the critical design issues in the case of heterogeneous wireless networks is regarding the vertical handoff support. Vertical handoff happens when a mobile terminal makes a switch from one network to another (e.g., from WLAN to CDMA 1xRTT). The aim of this work is about determining the circumstances during which the vertical handoff has to be performed. Typically, a mobile user can roam and achieve the vertical handover making use of single criteria, like the Received Signal Strength (RSS). However the decision of single criteria vertical handover, might lead to a handoff that is inefficient, imbalanced network load, and service disruption. For the purpose of improving the accuracy pertaining the vertical handoff decision for use in radio heterogeneous network, this paper presents a Hybrid Particle swarm optimization based Multi criteria Vertical Handoff (HPMVHO) decision algorithm employing multi criteria metrics in the heterogeneous network environment that consists of three network interfaces: (i) Wireless Local Area Network (WLAN), (ii) Wideband Code Division Multiple Access (WCDMA), and (iii) Worldwide Interoperability For Microwave Access (WiMAX). In vertical handover decision, the metrics including Received Signal Strength (RSS), Network Throughput, bandwidth available, Power consumption, Expenditure, Security and user choices are taken into consideration. In the HPMVHO decision algorithm proposed, Fuzzy logic is applied for representing the inaccurate information of some of the attributes and user preferences. The Fuzzy logic considers the crucial criteria of the vertical handoff in the form of the input variables and then the handoff decision is made on the basis of the weight values defined. The weight values to every service has to be assigned in accordance with the quality with respect to the services parameters to each of the sensor on the basis of the Hybrid Particle Swarm Optimization (HPSO). The Extreme Learning Machine (ELM) assists in making the prediction for the number-of-users belonging to the after-handoff network that plays the role of a pivotal variable of the HPSO. This algorithm renders precise decision by using reasonable inference for designing the crucial multi criteria and then deciding over efficient decision technique. Finally, examples illustrating the proposed techniques are given, and the sensitivity of the strategies are examined.

Secured Token Based Handover (STBH) Algorithm for Traffic Collision alert in VANETs

Vehicular Ad-Hoc Network or VANET is a technology in which moving cars acts as nodes of a mobile network. Vehicular Ad-hoc Networks paves a way for Intelligent Transportation Systems (ITS). In a network of nodes if a nodal vehicle fall out of signal and gets drop out of the network, then there should be a replaceable vehicle that would help to repair the disconnection of the network by facilitating uninterrupted data transmission. This can be made possible through various handover techniques available. Using GPS, the fastest route to transfer the data is analyzed. To manage the Always Best Connected (ABC) requirement, available vertical soft handover decision strategies are being analyzed in this paper. This paper also proposes a new Secured Token Based vertical soft handover method, which relies on token system using FCFS process. A temporary node is used as a replaceable node during handover to avoid data loss.