Handoff Scheme Research Articles

Performance Evaluation of Multi-Interfaced Fast Handoff Scheme for PNEMO Environment

Mobility management is classified into two parts such as location management and handoff management. The earlier one concentrates on location update whereas the later one manages continuous Internet connectivity while the Mobile Router (MR) changes its single point of attachment to the network. Therefore, frequent movement of the MR is one of the significant characteristics in Network Mobility (NEMO) environment. Because, in accordance with the standard Network Mobility Basic Support Protocol (NEMO BSP), the MR utilizes single Interface to attach to the access link. MR requires changing its Care of Address (CoA) when it moves among different wireless access networks. As a result, it can directly influence the performance of the mobility management protocols during inter technology handoff of multi-interfaced MR. This paper proposed a multi-interfaced fast handoff scheme in Proxy NEMO (PNEMO) environment. After that, it represents a comparative analysis between the proposed multi-interfaced scheme, NEMO BSP and the PNEMO scheme respectively. The performance disparities of these schemes are estimated and analyzed via both numerical and simulation approaches. The simulation is performed through NS-3 network simulator. The performance metrics estimated for evaluation are mainly handoff delay and packet loss. It has been perceived that, the proposed scheme performs better compared to the PNEMO scheme and NEMO BSP.DOI: http://dx.doi.org/10.5755/j01.eie.24.5.21848

Multi-Objective Handoff Scheme for Macro/Femto WiMAX Networks

Femtocell plays a significant role in technologies to improve service quality and data rates for indoor mobile users. It is the recent less expensive concept that provides better indoor coverage. Therefore, handoff process from macrocell to femtocell is an open research issue. In this paper, an adaptive macro/femto handoff scheme is proposed. It takes into consideration the velocity of mobile station, load balancing and the accessing mode of the target cell. It effectively handles the indoor handoff situations by checking user velocity which has to be lower than a threshold value in order to guarantee that this user has a sufficient time to switch from macrocell to femtocell. The proposed scheme aims to achieve load balancing between macrocells and femtocells. It also minimizes the number of femtocells in the neighbor cell list. The target femtocell is predicted based on the direction of the mobile user considering the femtocells accessing mode. Numerical results show that the proposed scheme improves femtocell usage and decreases the handoff latency and the total handoff delay compared to the standard macrocell-to-femtocell handoff process and other existing schemes.

Design, analysis and implementation of a time-bounded spectrum handoff algorithm for real-time industrial wireless sensor and actuator networks

Industrial control applications require real-time communication systems with time-critical and safety-critical features, as well as the ability to operate in harsh propagation environments. This means that data communications need to be bounded both in time and reliability domains, while dealing with severe interference coming from other wireless communication systems, including jammers, and with signal degradation phenomena such as delay spread, deep fading or Doppler spread. The present work proposes a spectrum handoff (i.e. channel switching) mechanism for Industrial Wireless Sensor and Actuator Networks (IWSAN) which is capable of detecting interferences and hopping to another channel within a given time bound. This is possible because the spectrum handoff strategy is capable of detecting interference in the MAC layer with the high requirements demanded by real-time IWSAN applications in terms of time and reliability. A theoretical analysis has first been provided using Network Calculus, which determines the delay bounds, and simulations in OPNET have been done afterwards in order to validate the theoretical results, taking into account several industrial environments (e.g. lognormal shadowing, Rice and Rayleigh fading and interference). Furthermore, the proposed communication system, based on the IEEE 802.11a/g physical layer, has been implemented in a FPGA, and simulations in OPNET network simulator and measurements on real hardware have been carried out in order to characterize its performance. The obtained results prove the capability of the proposed spectrum handoff mechanism to guarantee bounded delays and reliable operation in harsh propagation environments with interference, what makes it a suitable candidate for replacing wired communication systems in industrial environments.

A Multi-Armed Bandit Model-Based Vertical Handoff Algorithm for Heterogeneous Wireless Networks

Vertical handoff is widely accepted as an important issue for ensuring seamless communication in heterogeneous wireless networks. This letter proposes a multi-armed bandit model-based vertical handoff approach (MABA). First, the vertical handoff problem is formulated as a multi-armed bandit problem. Then, the terminal services are divided into real-time services and non-real-time services, and their reward functions are constructed respectively. Finally, the Gittins indices of networks in different states are calculated by the state-elimination algorithm (SEA). Based on the Gittins theorem, the handoff strategy for maximizing the benefit of the system is obtained. Simulation results indicate that the proposed approach could select optimal networks for users with different types of services and reduce blocking probability of the system, thereby improving the performance of the system.

Hybrid Hand-off Scheme for Performance Improvisation of Wireless Networks

Wireless systems administration is turning into an inexorably significant and well known method of giving worldwide data access to clients progressing. Handoff, the procedure where portable hubs select best passageway accessible to move information and its postpones make a major issue. A great deal of research has been done in most recent years to diminish the handoff delays happen in the various degrees of WLAN correspondence. Because of the versatility of handoff, significant viewpoint in WLAN and cell correspondences are substantially more significant. Because of constrained scope of APs, WLAN likewise gives adequate data transmission to continuous spilling administrations. In this research article, various handoff plans are proposed to diminish the hand-off idleness and bolster quick hand-off in IEEE 802.11arcchitecture of wireless networks. In this article, we survey these quick handoff plots subjectively. In this work it is to make accessible preparation for prospect research on lessening the handoff inertness and give accentuation on necessity of quick handover for consistent network.

공공 Wi-Fi 네트워크에서 수신 신호 세기 이력 기반의 핸드오프 기법

공공 Wi-Fi 네트워크에서 수신 신호 세기 이력 기반의 핸드오프 기법

Performance Analysis of Handover Schemes in Heterogeneous Networks

Internet protocol (IP)-based mobile systems are ushering new and faster technologies in wireless mobile networking. Therefore, the expectations from these network services with respect to data transfer rate and quality of service (QoS) are high. As such, meeting these requirements is the recent trend in modern wireless technologies. An important aspect regarding such improvements is the modification of handoff schemes between different networks. In this paper, we are focusing on the recent trends based on seamless handoff scheme in heterogeneous networks such as worldwide interoperability for microwave access (WiMAX) and long term evolution (LTE). The development of the session initiation protocol (SIP) Prior-INVITE scheme is an improvement on the earlier used SIP Re-INVITE method, which comes a long way in decreasing the average handoff delay. The performance analysis using software simulation on account of various parameters, such as handoff delay, cost of signaling and packet loss rate are accomplished in this work. The performance analysis demonstrates that the proposed scheme outperforms the ordinary cross-layer scheme and noncross-layer scheme in a vertical handover scenario.

Call Admission Control for Non-Standalone 5G Ultra-Dense Networks

In this letter, we propose new handoff schemes to reduce the interruption time that occurs during re-connection of an arriving mobile user moving from macrocell to small cell or from small cell to macrocell domains. A new call admission control function is developed to adjust thresholds during handoff request signaling. To perform the handoff operation, Markov chain technique is used to analyze the call blocking probability characteristic and subsequently to decide handoff approval for various subscriber requests. Numerical results show that the proposed admission control mechanism is able to minimize call blocking probability, without sacrificing resource utilization, and to reduce the number of service interruptions occurring during user re-connections.

Smart prediction for seamless mobility in F-HMIPv6 based on location based services

This paper proposed a new scheme for smooth handoff over F-HMIPv6 networks based on Location Based Services (LBS). It uses the available information about mobile node (MN) such as user mobility patterns and MN’s velocity to reduce handoff latency. In the proposed scheme, the movement pattern of users plays an important role in the performance analysis. The proposed scheme develops LBS that records a number of mobility patterns based on user daily behavior, and exploits these information to reduce the handoff latency. The proposed scheme is analyzed and compared with F-HMIPv6 protocol. The results show that it improves the performance in terms of handoff latency, packet delivery cost, and location update cost. Specifically, the proposed scheme achieves the tradeoff between realizing a smooth handoff and minimizing the cost that is the demand for all customers of mobile services.

Channel/Beam Handoff Control in Multi-Beam Antenna Based Cognitive Radio Networks

A novel spectrum handoff scheme, called feature stacking (FEAST) is proposed to achieve the optimal “channel + beam” handoff (CBH) control in cognitive radio networks (CRNs) with multi-beam smart antennas. FEAST uses the online supervised learning based on the support vector machine to maximize the long-term quality of experience of user data. The spectrum handoff uses the mixed preemptive/non-preemptive M/G/1 queueing model with a discretion rule in each beam to overcome the interruptions from the primary users and to resolve the channel contentions among different classes of secondary users (SUs). A real-time CBH scheme is designed to allow the packets in an interrupted beam of a SU to be detoured through its neighboring beams, depending their available capacity and queue sizes. The proposed scheme adapts to the dynamic channel conditions and performs spectrum decision in time- and space-varying CRN conditions. The simulation results demonstrate the effectiveness of our CBH-based packet detouring scheme, and show that the proposed FEAST-based spectrum decision can adapt to the complex channel conditions and improves the quality of real-time data transmissions compared to the conventional spectrum handoff schemes.

QUEUEING MODEL FOR SOFT HANDOFF ANALYSIS IN CDMA BASED WIRELESS CELLULAR NETWORK

The most important feature of the mobile network is mobility. Good and continuous service in cellular mobile network can be achieved by using the procedure of handoff (or handover) from one cell to another. Soft handoff is very important feature of cellular Code Division Multiple Access (CDMA) system. In CDMA system a mobile stations (MSs) within a soft handoff region use multiple radio channels and receive their signals from multiple base stations simultaneously. In CDMA cellular system, all cells can also share the same frequency. During handoff procedure, the signaling and voice information from multiple base stations are combined at the mobile switching center (MSC). During the handoff procedure, voice and signaling information must be sent to multiple base stations and the mobile station must combine the results. Within the overlapping area (which is developed by the adjacent cells) of cells, a handset can connect to multiple base stations. In this research paper, a new soft handoff scheme for CDMA cellular network is proposed and investigated. Here we introduce the concept of overlap region between adjacent cells and develop an analytical model for soft handoff in CDMA system. In developed soft handoff model, the balking and reneging behaviors of handoff calls have also considered. Different performance measures of the soft handoff model have developed.

Enabling fast handoff in dense 802.11 WMNs via temporal-spatial knowledge and opportunistic probing

Recently the deployment of IEEE 802.11 Wireless Mesh Networks (WMNs) has been growing exponentially attributing to sharing economy of WiFi. As a result, the handoff delay caused by mobile client (MC) probing for the next preferred AP imposes more challenges for time-sensitive mobile applications such as VoIP, video chat, and IoT in a dense WMN with more and more MCs and APs. In this work, we exploit the characteristic of dense network and propose two fast handoff schemes, namely T-NRS (Temporal-Network Radio Signature) and OppoScan. T-NRS scheme leverages historical knowledge of associated APs in time series together with radio signature technique based on spatial knowledge to assist in fast handoff, while OppoScan scheme opportunistically leverages nearby MCs and APs to produce the required information of neighboring AP for handoff and thus significantly decrease the number of switching channel of APs. We implement and evaluate the mechanisms in testbed of about 200 APs in shopping malls. The results prove that the performance of the proposed schemes is satisfactory while cost less than previous approaches.

A hardware testbed for learning-based spectrum handoff in cognitive radio networks

A real-time cognitive radio network (CRN) testbed is implemented by using the universal software radio peripheral (USRP) and GNU Radio to demonstrate the use of reinforcement learning and transfer learning schemes for spectrum handoff decisions. By considering the channel status (idle or occupied) and channel condition (in terms of packet error rate), the sender node performs the learning-based spectrum handoff. In reinforcement learning, the number of network observations required to achieve the optimal decisions is often prohibitively high, due to the complex CRN environment. When a node experiences new channel conditions, the learning process is restarted from scratch even when the similar channel condition has been experienced before. To alleviate this issue, a transfer learning based spectrum handoff scheme is implemented, which enables a node to learn from its neighboring node(s) to improve its performance. In transfer learning, the node searches for an expert node in the network. If an expert node is found, the node requests the Q-table from the expert node for making its spectrum handoff decisions. If an expert node cannot be found, the node learns the spectrum handoff strategy on its own by using the reinforcement learning. Our experimental results demonstrate that the machine learning based spectrum handoff performs better in the long term and effectively utilizes the available spectrum. In addition, the transfer learning requires less number of packet transmissions to achieve an optimal solution, compared to the reinforcement learning.11DISTRIBUTION STATEMENT A: Approved for Public Release; distribution unlimited 88ABW-2017–6274; 13 Dec 2017.

Prioritized Handoff Scheme with Imperfect Sensing for Secondary Users in Cognitive Radio Networks

Prioritized Handoff Scheme with Imperfect Sensing for Secondary Users in Cognitive Radio Networks

A Spectrum Handoff Scheme for Optimal Network Selection in NEMO based Cognitive Radio Vehicular Networks: A Cost Function MADM Method based on Grey Theory based Approach

Multiple Attribute Decision Making (MADM) is one of the intelligent network selection methodologies for Intelligent Transportation System (ITS). The fundamental objective of MADM method is to select the optimal network among the finite set of alternative. In this paper, we have proposed a cost function MADM method based on the grey theory based approach which outperforms the existing MADM method for ITS. The method is validated to perform a spectrum handoff for optimal network selection in Network Mobility (NEMO) based Cognitive Radio (CR) vehicular networks. In NEMO based CR vehicular networks, the Mobile Reuter (MR) requires spectrum handoff when a mobile network changes its point of attachment in CR vehicular networks. It becomes difficult for MR to select the optimal network from the available access networks. The application of MADM methods provides wider and optimum choice among the available networks with quality of service. Numerical results revel that the proposed MADM method is effective for spectrum handoff decision for optimal network selection with reduced complexity in NEMO based CR vehicular networks.

QoE-Aware Intelligent Vertical Handoff Scheme Over Heterogeneous Wireless Access Networks

As a measurement, quality of service (QoS) has been commonly taken into account in the traditional vertical handoff schemes for the heterogeneous wireless access networks. However, the QoS is not sufficient to correlate well with the user satisfaction. In this paper, quality of experience (QoE) is introduced into the decision mechanism of the vertical handoff and a random neural network -based QoE estimation is proposed to determine the correlation between the QoE and the QoS in the heterogeneous networks. In addition, a Q-learning-based vertical handoff algorithm, designated as a QoE-Q algorithm, is presented in order to maximize the QoE utility for users. It can be observed from the simulation results that the proposed method not only outperforms the existing schemes with enhanced call blocking probability and handoff dropping probability property but also obtains better QoE performance in the service charges and the terminal power consumption than other schemes.

Vertical Handoff in Wireless 4G Heterogeneous Networks

In today’s high-speed communication era, when a user moves from one network to another, voice call and video streaming should not be interrupted. Different wireless network technologies such as WLAN, a cellular network, WiMAX coexist and they have different data rate and different area of coverage. Therefore, it is very challengeable to design an efficient vertical handoff scheme which will satisfy the seamless connectivity and provide Quality of Service(QoS). The aim of this paper is the different classification of handoff and survey the existing vertical Handoff decision making algorithms.

Time triggered handoff schemes in cognitive radio networks: A survey

Rapid development in wireless networks has largely raised the demand for spectrum bandwidth. However, current static spectrum allocation policy is unable to meet this ever-growing requirement which causes the spectrum scarcity problem. Cognitive radio network (CRN) has emerged as a grasping solution to scarcity problem where the secondary or unlicensed users are allowed to access the temporary free channels owned by the licensed or primary users. Among other important steps involved in a spectrum management process, handoff plays an essential role since it requires shifting the on-going transmission of a secondary user (SU) to a free channel without degrading the quality of service. An extensive work has been done in the field of spectrum handoff for CRNs. This work is mostly classified in timing, probability, and operating mode based handoff schemes. In this paper, we present a detailed classification and a compressive survey for time triggered handoff schemes. This topic is chosen because in time triggered handoff process, the handoff decision needs to be performed based on continuously sensing the arrival and departure patterns of licensed users, thus making it an important area of research. Therefore, we discuss the pros and cons for time triggered handoff schemes in detail.

Genetic Based Approach to Optimize the Vertical Handover Performance Among Heterogeneous Network

Mobile terminals typically can be connected to multiple wireless networks that offer different degrees of suitability for different classes of service. A genetic algorithm (GA) - based on a supervised approach - is used to assess the likelihood of a successful handover in heterogeneous networks to increase capacity and network performance. Traditional handoff schemes are prone to ping-pong and corner effects, and the development of an optimized handover scheme for a seamless, faster and less energy-consuming handover decision is a challenge. In order to ensure service continuity and to maintain the promising QoS, the handover decision should be made appropriately. The most general criteria for handover is the received signal strength, which is not sufficient in advanced networks. The GA scheme can effectively optimize the soft handoff decision by using the best-fit network for the mobile terminal (MT), taking into account the quality of service requirements (QoS), the network parameters, and the user preference for the cost of the various connection points for the MT is selected. The mathematical model-based approach to vertical handoff prediction involves a well-defined objective function taking into account signal strength, user equipment speed, load and cost per user bandwidth. The system performance can be improved according to the user settings by adjusting the weights in the defined objective function. Due to the high bandwidth and easy networking, the system consider the wireless access standards: UMTS, Wi-Fi, LTE and Wimax. The decision problem is formulated as several objective optimization problems and simulated using a monitored genetic algorithm. The simulation result shows that the number of handovers can be minimized when using optimized network parameter values.

Ant Colony Optimization Based Handoff Scheme and Verifiable Secret Sharing Security with M-M Scheme for VoIP

Ant Colony Optimization Based Handoff Scheme and Verifiable Secret Sharing Security with M-M Scheme for VoIP