Vertical Handoff Performance Research Articles

MUACLP Modeling Unified Architecture of Cross Layer Parameters Strategy of Handoff for Next Generation Wireless Network

The Quality of Service and Quality of experience is always a goal of future generation wireless systems. A suitably designed handoff plays an important role in achieving these goals. The traditional methods of handoff for wireless systems pose challenges in handling the smooth transition in the heterogeneous architecture of future generation architecture. This paper induces a model for synchronization of seamless handoff for a mobile user from a unified access point of a large cell to the small cell. The study is carried out considering a novel analytical model for facilitating a better form of vertical handoff mechanism in order to facilitate communication over 5G networks. The modeling is carried out considering the efficiency of channel capacity as well as considering near real-time constraint of latency and throughput. The typical design assumption for the unified architecture of the model for the handoff is for future generation wireless network that includes various physical layer parameters. For an effective analysis, the study considers that the receiving node will be identified on the basis of the non-erroneous node as the idea is to increase the proper utilization of the network resources. The core agenda of the study will be to ensure that irrespective of any form of traffic intensity as well as variable resource availability, the proposed scheme should be able to offer an extensive communication with the seamless performance during handoff operation. The study outcome exhibits that the proposed system offers better vertical handoff performance in contrast to the existing system on various test cases.

Implementation of Vertical Handoff Over LTE, Wi-Fi and WiMAX Networks

The forthcoming wireless networks provide the continuous services to their users for different applications by the integration of diverse wireless access technologies known as heterogeneous wireless network. The heterogeneous wireless network improves the Quality of Service for stationary and non-stationary mobile users. Even when users are in mobility the services are provided by means of handoff or handover. In this paper, the integration of three different wireless networks such as LTE, WiMAX and Wi-Fi networks and their vertical handoff performance analysis are presented. These diverse wireless networks which are considered for integration are modeled as a heterogeneous wireless network. This network is designed using QualNet simulator. Furthermore, the designed heterogeneous network, vertical handoff performance is estimated by using factors such as throughput, jitter and End to End delay. With these performance factors, the designed network’s Quality of Service (QoS) is estimated under mobility conditions.

A Novel PROMSIS Vertical Handoff Decision Algorithm for Heterogeneous Wireless Networks

A novel preference ranking organization method by similarity to ideal solution (PROMSIS) vertical handoff algorithm is proposed for heterogeneous wireless networks, and its essential idea includes the preference structure of the PROMETHEE and the concept of Euclid distance of the TOPSIS. Four 3GPP defined traffic classes are considered in performance evaluation. An attribute matrix is constructed considering some major attributes. Handoff decision meeting multiattribute QoS requirement is made according to the traffic features. The weight relation of decision elements is determined with the least square (LS) approach. The final decision is made using the proposed PROMSIS algorithm based on the attribute matrix and weight vector. The simulation results have manifested that the proposed PROMSIS algorithm can provide satisfactory vertical handoff performance, and the LS-PROMSIS algorithm can be fit to the characteristics of the traffic.

Research on vertical handoff decision based on service history information and SINR for heterogeneous wireless networks

In this letter, we propose a SH (Service History) and SINR (Signal to Interference plus Noise Ratio) based PROMETHEE (SHS-PROMETHEE) vertical handoff (VHO) decision algorithm. An attribute matrix is constructed considering the SH information and the SINR in the source network and the equivalent SINR in the target network and so on. Handoff decision meeting multi-attribute QoS requirement is made according to the traffic features. The weight relation of decision elements is determined with LS method. Finally decision is made using PROMETHEE algorithm based on the attribute matrix and weight vector. The simulation results have shown that the SHS-PROMETHEE algorithm can reduce unnecessary handoffs and provide satisfactory vertical handoff performance.

Immune optimization algorithm for solving vertical handoff decision problem in heterogeneous wireless network

In heterogeneous wireless network environment, wireless local area network (WLAN) is usually deployed within the coverage of a cellular network to provide users with the convenience of seamless roaming among heterogeneous wireless access networks. Vertical handoffs between the WLAN and the cellular network maybe occur frequently. As for the vertical handoff performance, there is a critical requirement for developing algorithms for connection management and optimal resource allocation for seamless mobility. In this paper, we develop a mathematical model for vertical handoff decision problem, and propose a multi-objective optimization immune algorithm-based vertical handoff decision scheme. The proposed scheme can enable a wireless access network not only to balance the overall load among all base stations and access points but also maximize the collective battery lifetime of mobile terminals. Results based on a detailed performance evaluation study are also presented here to demonstrate the efficacy of the proposed scheme.

Seamless handoff across heterogeneous networks: A multi-objective optimization approach

The growing consumer's demand leads a great access to communication services anywhere and at anytime. It has started to accelerate the development of technologies that would allow for the integration of various Wireless Access Technologies. With regard to vertical handoff performance, there is a critical need for developing algorithms for connection management and optimal resource allocation for seamless mobility. This study proposes a novel Vertical Handoff Decision Making Algorithm (VHDMA) based on analytic multi-objective optimization. The multi-objective cost function involves transmit power of Mobile Terminals (MTs), outage and throughput over Access Points (APs)/Base Stations (BSs). The proposed algorithm lowers the barriers and jointly optimizes all the required objectives. The results showed that the Multi-Objective (MO) optimization has the advantages of optimizing over different and conflicting objectives jointly. Key words: Seamless mobility, heterogeneous networks, multi-objective (MO) optimization, vertical handover.

PERFORMANCE OF ADAPTIVE LIFE TIME BASED VERTICAL HANDOFF ALGORITHM IN HETEROGENEOUS NETWORKS

The convergence of heterogeneous wireless networks combines existing wireless networks. An effective combination of diff erent wireless networks should enable them to complement each other and pro vide high-speed data rate, wide area coverage, and quality of service (Q oS) guarantee. In Next Generation Wireless Systems (NGWS), seamless handof f between different wireless access networks plays a vital role. One of the major challenges for seamless mobility is the creation of a vertical han doff protocol. In this paper, the performance of vertical handoff is studi ed using the integration of third generation (3G) cellular and wireless loca l area networks (WLAN). The effect of application-based signal stre ngth threshold (ASST) and path loss exponent on an adaptive lifetime-base d vertical handoff (ALIVE-HO) strategy is studied in terms of number o f handoffs, aggregated throughput, and packet delay. Therefore the vertical handoff performance can be optimized in wireless and mobile networks. The present work is done for different channel conditio ns as well as different mobility schemes.

Simple harmonic oscillator immune optimization algorithm for solving vertical handoff decision problem in heterogeneous wireless network

In heterogeneous wireless network environment, wireless local area network (WLAN) are usually deployed within the coverage of a cellular network to provide users with the convenience of seamless roaming among heterogeneous wireless access networks. Vertical handoffs between the WLAN and the cellular network could occur frequently, with regard to vertical handoff performance, there is a critical need for developing algorithms for connection management and optimal resource allocation for seamless mobility. In this paper, we develop a mathematical model for vertical handoff decision problem, propose an artificial simple harmonic oscillator immune algorithm-based vertical handoff decision scheme, and perform the simulation experiments to validate proposed solution. Experimental result shows that the proposed solution, compared with literature solutions, can not only balance the overall load among all networks but also increase the collective battery lifetime of mobile terminals, and has the advantage of good application value.

Analytic Performability Model of Vertical Handoff in Wireless Networks

Problem statement: The next generation wireless systems should be designed to support heterogeneous traffic with seamless mobility. A single network alone cannot cope up with such heterogeneous requirements. Hence it is desirable to interoperate between diverse and complementary Radio Access Technologies (RATs). In such system, user will switch between different Radio Access Technologies (RATs) to satisfy the User/application requirement and this process is known as Vertical Handoff (VHO). The process of network switching had three phases, network discovery, handoff decision and execution. The decision phase played a crucial role in resource utilization and user/application Quality of Service (QoS) requirement. Hence it was essential to model and evaluate the handoff decision system along with VHO system model. Approach: The traditional performance models were optimistic models and would evaluate the system performance under ideal condition by ignoring failures and recovery in the system. The availability models were conservative models and would assess the availability/reliability of the system. The performabality models were combined models of performance and reliability. The performablity models were more realistic models of the system due to the simultaneous consideration of performance and reliability. Here the VHO process of a next generation wireless system was modeled and evaluated by an analytic performablity model and performance of decision system is evaluated through the sensitivity analysis of VHO decision parameter. Results: In VHO performance evaluation, the metrics of performance evaluation are handoff dropping probability and new call blocking probability. The dynamics of these metrics are depends on set of wireless network parameter such as Available Bandwidth (ABW), users, Bit Error Rate (BER) and network traffic. The ABW, BER and network traffic is also parameter for VHO decisions. The results of performance evaluation are used to develop a novel intelligent vertical handoff decision technique to achieve optimum tradeoff between set of handoff decision criteria. Finally, sensitivity analysis of system parameters on four traffic classes and two vertical handoff decision algorithms along with intelligent vertical handoff decision method were presented. Conclusion: The results of sensitivity analysis depicted that the VHO process in next generation wireless system needs intelligent criteria based technique at the decision making phase of VHO process.

Vertical Handoff Decision Algorithms for Providing Optimized Performance in Heterogeneous Wireless Networks

There are currently a large variety of wireless access networks, including the emerging vehicular ad hoc networks (VANETs). A large variety of applications utilizing these networks will demand features such as real-time, high-availability, and even instantaneous high-bandwidth in some cases. Therefore, it is imperative for network service providers to make the best possible use of the combined resources of available heterogeneous networks (wireless area networks (WLANs), Universal Mobile Telecommunications Systems, VANETs, Worldwide Interoperability for Microwave Access (WiMAX), etc.) for connection support. When connections need to migrate between heterogeneous networks for performance and high-availability reasons, seamless vertical handoff (VHO) is a necessary first step. In the near future, vehicular and other mobile applications will be expected to have seamless VHO between heterogeneous access networks. With regard to VHO performance, there is a critical need to develop algorithms for connection management and optimal resource allocation for seamless mobility. In this paper, we develop a VHO decision algorithm that enables a wireless access network to not only balance the overall load among all attachment points (e.g., base stations and access points) but also maximize the collective battery lifetime of mobile nodes (MNs). In addition, when ad hoc mode is applied to 3/4G wireless data networks, VANETs, and IEEE 802.11 WLANs for a more seamless integration of heterogeneous wireless networks, we devise a route-selection algorithm for forwarding data packets to the most appropriate attachment point to maximize collective battery lifetime and maintain load balancing. Results based on a detailed performance evaluation study are also presented here to demonstrate the efficacy of the proposed algorithms.

An analytical evaluation of mobility management in integrated WLAN-UMTS networks

Ensuring uninterrupted service continuity for handoff calls in an all-IP inter-networked heterogeneous environment requires successful session management among participating access networks. As such, a mobility-aware novel interworking architecture is presented in this article that facilitates session management including session establishment and seamless session handoff across different networks. This framework conveniently enables any 3G cellular technology such as the Universal Mobile Telecommunications System (UMTS) to interwork with a given Broadband Wireless Access (BWA) technology such as the Worldwide Interoperability for Microwave Access (WiMAX) network or the Wireless Local Area Network (WLAN) under a common signaling platform. This framework exploits the IP Multimedia Subsystem (IMS) as a universal coupling mediator for real-time session negotiation and management. Next, a Queuing Theory based analytical model for evaluating the performance of vertical handoff management between these interworked 3rd Generation (3G) cellular networks and the WLANs is presented. The analysis includes vertical handoff performance measures such as delay, transient packet loss, jitter, and signaling overhead/cost. The latter part of this paper presents some results from OPNET based simulations for the verification of the analytical model and results.

Advanced seamless vertical handoff architecture for WiMAX and WiFi heterogeneous networks with QoS guarantees

The development of wireless networks brings people great convenience. More state-of-the-art communication protocols of wireless networks are getting mature. People attach more importance to the connections between heterogeneous wireless networks as well as the transparency of transmission quality guarantees. In this paper, WiFi wireless networks and WiMAX mobile communication system are selected as our research subjects. VHTC (Vertical Handoff Translation Center Architecture) is proposed to improve the transmission QoS guarantees. Thus, the quality of transmission cannot be reduced enormously even by the effect of vertical handoff between heterogeneous wireless networks. This paper includes new approaches and architecture among Packet Translation, QoS Mapping, Bandwidth Borrowing Management and Vertical Handoff Protocol with a view to achieve the goal, that is, an advanced seamless heterogeneous wireless networks. Also, through the modification of WiFi module of TKN and WiMAX module of NIST, these two heterogeneous wireless networks can be connected and embedded in NS2 (Network Simulator version 2) simulation system. Afterwards, the methods, proposed in this paper, can be implemented in such simulation system. Finally, lots of satisfactory simulation results about throughput, delay, jitter and packet loss rate were given to show the brilliant performance of vertical handoff implemented by VHTC.

A client‐based vertical handoff approach for seamless mobility across heterogeneous wireless networks

AbstractWith the rapid growth of mobile Internet, offering seamless connectivity in different types of wireless networks is an important feature in next generation wireless networks (4G networks). Mobile IP (MIP) is expected to play a key role to handle the movements of mobile nodes (MNs) in 4G networks. However, MIP suffers from long handoff latency since it is designed to support the macromobility of a MN. Therefore, it is necessary to devise a scheme that provides currently deployed networks with backward compatibility and that offers seamless connectivity during MIP handoffs across the heterogeneous wireless networks. In this paper, we propose a client‐based vertical handoff system for multi‐networks to provide end‐users with seamless connectivity across heterogeneous wireless networks. Our proposed system is designed as a common network interface at a client side and provides transparent service to IP/MIP layers regardless of used wireless technologies. With this system, we also present vertical handoff performance over a loosely coupled cdma2000/WLAN experimental test‐bed. The experimental results show that our system enables a MN to handoff seamlessly across different types of wireless networks without any modifications to the existing IP/MIP stack and core network. Copyright © 2008 John Wiley & Sons, Ltd.

Signal threshold adaptation for vertical handoff in heterogeneous wireless networks

The convergence of heterogeneous wireless access technologies has been envisioned to characterize the next generation wireless networks. In such converged systems, the seamless and efficient handoff between different access technologies (vertical handoff) is essential and remains a challenging problem. The heterogeneous co-existence of access technologies with largely different characteristics results in handoff asymmetry that differs from the traditional intra-network handoff (horizontal handoff) problem. In the case where one network is preferred, the vertical handoff decision should be carefully executed, based on the wireless channel state, network layer characteristics, as well as application requirements. In this paper, we study the performance of vertical handoff using the integration of 3G cellular and wireless local area networks as an example. In particular, we investigate the effect of an application-based signal strength threshold on an adaptive preferred-network lifetime-based handoff strategy, in terms of the signalling load, available bandwidth, and packet delay for an inter-network roaming mobile. We present an analytical framework to evaluate the converged system performance, which is validated by computer simulation. We show how the proposed analytical model can be used to provide design guidelines for the optimization of vertical handoff in the next generation integrated wireless networks.