Handover Scheme Research Articles

An Efficient Data Dissemination and Handover Scheme for Vehicular Ad hoc Networks

This paper presents a data dissemination and smooth handover scheme for vehicular ad hoc network. The data dissemination scheme is based on position-based routing class protocol and uses optimise forwarding to find forwarding node along the road pattern to deliver the data packets. The proposed routing algorithm ensures that all data packets are received with minimal delay and higher delivery ratio. A heterogeneous network architecture is proposed in this paper to support seamless mobility of mobile network. Each vehicle is provided with mobility through different internet server protocols (ISPs). The mobile router (MR) based handover scheme where MRs cooperatively receive packet destined for each other can provide no service disruption and significantly reduce packet loss during handover. It also makes the packet loss independent to handover latency. Simulation study shows the comparative performance of the proposed handover architecture in terms of throughput, handover latency service disruption time, packet loss and signalling overhead.

Power Aware Mobility Management of M2M for IoT Communications

Machine-to-Machine (M2M) communications framework is evolving to sustain faster networks with the potential to connect millions of devices in the following years. M2M is one of the essential competences for implementing Internet of Things (IoT). Therefore, various organizations are now focusing on enhancing improvements into their standards to support M2M communications. Thus, Heterogeneous Mobile Ad Hoc Network (HetMANET) can normally be considered appropriate for M2M challenges. These challenges incorporated when a mobile node (MN) selects a target network in an energy efficient scanning for efficient handover. Therefore, to cope with these constraints, we proposed a vertical handover scheme for handover triggering and selection of an appropriate network. The proposed scheme is composed of two phases. Firstly, the MNs perform handover triggering based on the optimization of the Receive Signal Strength (RSS) from an access point/base station (AP/BS). Secondly, the network selection process is performed by considering the cost and energy consumption of a particular application during handover. Moreover, if there are more networks available, then the MN selects the one provided with the highest quality of service (QoS). The decision regarding the selection of available networks is made on three metrics, that is, cost, energy, and data rate. Furthermore, the selection of an AP/BS of the selected network is made on five parameters: delay, jitter, Bit Error Rate (BER), communication cost, and response time. The numerical and experimental results are compared in the context of energy consumption by an MN, traffic management on an AP/BS, and QoS of the available networks. The proposed scheme efficiently optimizes the handoff related parameters, and it shows significant improvement in the existing models used for similar purpose.

Cross layer trigger-based handover scheme for mobile WiMAX networks

Wireless interoperability for microwave access WiMAX networks have recently emerged to be a cost-effective solution to provide broadband access over a large coverage area. To maintain service continuity and guarantee the QoS in real-time applications for mobile users, handover delay is one of the main challenges. In this paper, cross layer trigger-based handover scheme is proposed which will be able to offer uninterrupted services to mobile users. The basic idea behind this scheme is to achieve a global optimality by utilising the advantages of cross layer interactions between link layer and network layer. The cross layer triggers generated at lower layers, intimate higher layers about an imminent handover and allow execution of handover processes in layer 2 and layer 3 simultaneously. The analytical and simulation results show that the proposed mechanism enhances the handover performance in terms of handover delay and latency, which, in turn, reduces signalling overload and service disruption significantly.

An Enhanced Secure Mobility Management Scheme for Building IoT Applications

Abstract In this paper, we analyze the Kang-Park and ESS-FH scheme, and propose an Enhanced Secure-Mobility Data Management Scheme for FPMIPv6 (ESS-FP). Based on the CGA method and public key Cryptography, ESS-FP provides a strong key exchange and key independence, in addition to improving the weaknesses of Fast Handover for Proxy Mobile IPv6 (FPMIPv6). We formally verify the proposed scheme based on BAN (Burrows, Abadi, and Needham) Logic, and analyze and compare its handover latency with those of the Kang-Park scheme and ESS-FH. In addition, we propose an inter-domain fast handover scheme for PMIPv6, using the proxy-based FPMIPv6. Furthermore, we apply an Enhanced Secure-Mobility Data Management Scheme for FPMIPv6 in the Internet of Things (IoT) environments.

Handover Management based on Asymmetric Nature of LTE-A HetNet using MCDM Algorithm

This paper proposes an efficient handover scheme considering the asymmetric characteristics of macro and pico cells in LTE-A HetNet. The proposed scheme detects a suitable target eNB for handover using a multi-criteria decision making algorithm and the mobility information of user equipment (UE). A prompt handover is triggered for the UE if the received power is too low or the downlink SINR is below a threshold, avoiding radio link failure. The simulation results reveal that the proposed scheme significantly enhances goodput while reducing packet loss and unnecessary handover.

PMIPv6 도메인에서 MPTCP 기반 Handover 기법

PMIPv6 도메인에서 MPTCP 기반 Handover 기법

Improving Handover and Drop-off Performance on High-Speed Trains With Multi-RAT

Provisioning commercial mobile telecommunications service on a high-speed train (HST) faces several challenges. In particular, when an HST quickly passes through the radio coverage of the base stations, frequent handovers may result in serious communication interruption. Methods such as the hierarchical two-hop network and the seamless dual-link handover scheme were proposed to address these challenges. This paper proposes the multiple radio access technology (multi-RAT) to resolve the HST handover issue, which allows the HST to simultaneously connect to two or more heterogeneous mobile networks (e.g., the Universal Mobile Telecommunications System and Long Term Evolution). With this approach, the handover process can be improved by keeping multiple heterogeneous network links of the HST at the same time and maintaining the connection through one link during the handover process of the other link. We show that multi-RAT can effectively enhance HST communications by reducing the impact of handover failure. This approach can work together with other solutions such as the dual-link scheme to further enhance the performance of the HST communications.

선박 내 Peer-to-Peer 다운로드 서비스를 위한 효율적인 핸드오버 기법

스마트 디바이스의 확산과 멀티미디어 콘텐츠에 대한 수요 증가로 인해 인터넷 트래픽이 급증하고 있다. 최근 크루즈선과 같은 대형 선박을 설계할 때, 지상 환경과 유사하게 해양 및 선박 내 환경에서도 다양한 IT 서비스를 제공할 수 있는 네트워크 설계가 고려되고 있다. 본 논문에서는 크루즈선과 같은 대형 선박 내부에서 효과적인 멀티미디어 콘텐츠 분배를 위한 무선 P2P (peer-to-peer) 통신시나리오를 고려하고, 멀티미디어 콘텐츠의 다운로드 서비스를 원활히 수행하기 위한 효율적인 핸드오버 기법을 제시한다. 제안한 방식은 핸드오버 시 기존의 방식이 신호 세기만을 고려하여 핸드오버를 수행하는 것과 달리, 인접 셀의 피어의 품질을 고려하여 핸드오버 히스테리시스 마진을 적응적으로 조절함으로써, 무선 P2P를 통한 멀티미디어 콘텐츠의 다운로드 속도를 개선함을 보였다. 제안한 방식은 선박 내 네트워크 (ship-area-network: SAN)에서 무선 P2P 통신을 통한 멀티미디어 콘텐츠의 공유과정에서 사용자들에게 효율적으로 콘텐츠를 제공할 수 있는 기술로 기대된다. Internet traffic is rapidly increasing due to the spread of personal smart devices and the demand for multimedia contents. When designing a large ship such as cruise, network architecture is also considered which supports various IT services in a maritime environment similar to the ground environment. In this paper, we consider wireless P2P (peer-to-peer) communication for efficient multimedia content sharing and propose novel handover scheme for efficient download service. The proposed handover method shows that it can improve the download symbol rates for handover in a wireless P2P system considering the signal strength and quality of peers as well. The proposed system is expected to provide efficient contents distribution and reliable communication in the ship-area-network (SAN).

Optimized handover strategy with hybrid satisfaction mechanisms

One of the key features of cellular systems is the possibility to switch the connection over several cells while the user is moving. This handover between cells has been upgraded to tackle different operator/users' objectives, and even it has been proposed between two access technologies for what is known as vertical handover. The long term evolution-advanced technology uses two kinds of cells within its coverage design, the macrocell to provide larger coverage at the extent of lower data rate; and the smallcell (i.e., femtocell) that is designed for very high data rate while low coverage is provided. Therefore, special mechanisms for handover between macrocells and smallcells are required. Along this paper we propose two handover mechanisms over such scenario where the objectives vary among larger data rate, lower energy consumption and load balancing. Special concern is given to green communications that have emerged as one of the most important trends in wireless communications because of its several advantages of interference reduction, battery life increase and electrical bill cut. The presented handover mechanism can tackle more than one objective at a time in order to provide satisfaction both to the operator and users. Interesting conclusions are obtained about the presented approach through computer simulations.

A moving direction prediction-assisted handover scheme in LTE networks

Abstract The 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) defines a wireless network standard for high packet transmission rate and low packet latency provisions. Handover is one of the important features for helping user equipments (UEs) to roam between LTE networks. However, LTE networks adapt a make-before-break handover procedure, which may cause a brief disconnection, therefore results in the packet transmission delay and packet loss problems. In this paper, we propose a moving direction prediction-assisted handover scheme for LTE networks to lower the number of handovers. We first track the location of user equipments (UEs) to predict their moving direction. By referencing previous locations, the next moving direction of UEs is estimated with the cosine function in order to determine the candidate E-UTRAN NodeBs (eNBs) for handover. Then, a target eNB is selected from the candidate eNBs through an angle-based dynamic weight adjustment scheme. By selecting a proper target eNB for handover, thus the quality of network transmission can be enhanced. Simulation results demonstrate the ability of the proposed scheme in reducing 17% average handover times, compared with the standard handover procedure, thereby reducing 12% average number of packet loss and 5% average packet delay time.

Adaptive handover scheme for evolved multimedia broadcast multicast services in long‐term evolution networks

The evolved multimedia broadcast multicast services (E-MBMS) can bring television (TV) services to a small mobile phone. The E-MBMS has been proposed in the third generation partnership project long-term evolution standardisation to support both normal mobile phone and mobile TV capabilities on a single device. As the E-MBMS delivers the same content simultaneously to multiple E-MBMS users sharing the same subframe in the multicast broadcast single frequency network (MBSFN) area and has the benefit of short handover latency when handover occurs within the MBSFN area; it is important to increase the number of E-MBMS users to be supported within the MBSFN area in order to achieve better performance in terms of spectral efficiency and handover latency. To obtain the advantages mentioned above, the proposed adaptive handover scheme increases the handover hysteresis margin (HM) when an E-MBMS user moves from the serving MBSFN area to the target non-MBSFN area and decreases the handover HM when an E-MBMS user travels from the serving non-MBSFN area to the target MBSFN area. Simulation results show that the spectral efficiency can be improved by increasing the number of E-MBMS users in the MBSFN area. Also, it is shown that the lower handover latency can be achieved by reducing the additional handover signalling message exchanges.

Handover Scheme for 5G C/U Plane Split Heterogeneous Network in High-Speed Railway

Being a promising technology for fifth-generation (5G) communication systems, a novel railway communication system based on control/user (C/U) plane split heterogeneous networks can provide a high-quality broadband wireless service for passengers in high-speed railways with higher system capacity, better transmission reliability, and less cochannel interference. However, due to its special architecture where the C-plane and the U-plane must be split and supported by a macro Evolved Node B (eNB) and a phantom eNB, respectively, it would suffer more serious handover problem, particularly in intermacrocell handover, which directly degrades its applicability and availability in high-speed railways. Moreover, no technical specification has been released about this network architecture. Therefore, this paper focuses on redesigning and analyzing technical details and handover procedures based on Long-Term Evolution (LTE) specifications to guarantee the proposed system's practicability and generality and its analytical tractability. To resolve the handover problem, this paper proposes a handover trigger decision scheme based on GM(1, $n$) model of the grey system theory. By this scheme, the received signal quality from the $(N + hbox{1})$th measurement report can be predicted from the $N$th measurement period, and the predicted values can be then utilized to make the handover trigger decision. The simulation results show that the proposed scheme is capable of triggering handover in advance effectively and of enhancing handover success probability remarkably.

DIHAT: Differential Integrator Handover Algorithm with TTT window for LTE-based systems

Abstract Handover is one of the key operations in the mobility management of long-term evolution (LTE)-based systems. Hard handover decided by handover margin and time to trigger (TTT) has been adopted in third Generation Partnership Project (3GPP) LTE with the purpose of reducing the complexity of network architecture. Various handover algorithms, however, have been proposed for 3GPP LTE to maximize the system goodput and minimize packet delay. In this paper, a new handover approach enhancing the existing handover schemes is proposed. It is mainly based on the two notions of handover management: lazy handover for avoiding ping-pong effect and early handover for handling real-time services. Lazy handover is supported by disallowing handover before the TTT window expires, while early handover is supported even before the window expires if the rate change in signal power is very large. The performance of the proposed scheme is evaluated and compared with two well-known handover algorithms based on goodput per cell, average packet delay, number of handovers per second, and signal-to-interference-plus-noise ratio. The simulation with LTE-Sim reveals that the proposed scheme significantly enhances the goodput while reducing packet delay and unnecessary handover.

Seamless handover between unicast and multicast multimedia streams

With the deployment of heterogeneous networks, mobile users are expecting ubiquitous connectivity when using applications. For bandwidth-intensive applications such as Internet Protocol Television (IPTV), multimedia contents are typically transmitted using a multicast delivery method due to its bandwidth efficiency. However, not all networks support multicasting. Multicasting alone could lead to service disruption when the users move from a multicast-capable network to a non-multicast network. In this paper, we propose a handover scheme called application layer seamless switching (ALSS) to provide smooth real-time multimedia delivery across unicast and multicast networks. ALSS adopts a soft handover to achieve seamless playback during the handover period. A real-time streaming testbed is implemented to investigate the overall handover performance, especially the overlapping period where both network interfaces are receiving audio and video packets. Both the quality of service (QoS) and objective-mapped quality of experience (QoE) metrics are measured. Experimental results show that the overlapping period takes a minimum of 56 and 4 ms for multicast-to-unicast (M2U) and unicast-to-multicast (U2M) handover, respectively. The measured peak signal-to-noise ratio (PSNR) confirms that the frame-by-frame quality of the streamed video during the handover is at least 33 dB, which is categorized as good based on ITU-T recommendations. The estimated mean opinion score (MOS) in terms of video playback smoothness is also at a satisfactory level.

Coordinated of multi‐point and bi‐casting joint soft handover scheme for high‐speed rail

The high mobility of high-speed train brings great challenges to the current wireless communication, especially to the handover. How to reduce the interrupt time and enhance the handover performance is becoming a serious problem for high-speed rail (HSR). In this study, a coordinated of multi-point (CoMP) and bi-casting joint soft handover scheme for HSR is proposed, which is based on long-term evolution network architecture, and without any change to the existing network and the train. In the scheme, CoMP is used on air interface and bi-casting is used on S1 interface. With the binding triggering of CoMP and bi-casting, only one suit of signalling is needed and the system complexity is much simplified. Meanwhile, as much handover related information is stored in corresponding entity during the joining process of CoMP and bi-casting, the handover process is much simplified and converted into update of serving eNodeB. Compared with traditional handover scheme, it can be seen from theoretical analysis and simulation results that the handover delay is reduced remarkably and the handover performance is improved greatly.

An Effective Handover Scheme Based on Antenna Selection in Ground–Train Distributed Antenna Systems

Due to frequent handovers in broadband wireless communications for the high-speed railway system, communication interruption caused by handover failures could seriously degrade the users' experience. Aiming at reducing the handover failure probability, this paper proposes an effective handover scheme based on the distributed antenna system (DAS) and mobile-relay-aided two-link architecture, i.e., ground-relay link and relay-onboard link, where the mobile relay is mounted on top of the moving train. In addition, an antenna selection scheme with optimal power allocation is proposed to improve handover performance. Our simulation and analysis results show that the DAS structure with macrodiversity can reduce the unnecessary handovers, as well as reduce the handover failure and link outage probabilities compared with the traditional cell without DAS. In addition, the proposed DAS with an antenna selection scheme performs better in terms of handover failure and link outage probabilities than that of DAS with a equal power allocation (EPA) scheme.

Seamless and Secure Design for Subsequent Handover in Mobile WiMAX Networks

Handover performance plays a crucial role in ensuring the quality of real-time applications in WiMAX networks. In general, the total delay associated with the handover process can be divided into three category: i) link layer handover delay, ii) IP layer handover delay, iii) Security sub-layer handover delay, research shows that a large portion of the delay related to handover are actually comes from user authentication and network entry and re-entry, real-time applications such as VoIP and video streaming .require a minimum interruption for a suitable service, sadly the existing design of the handover scheme could not provide seamless safe connection, therefore the use of such application will be unlikely, in this paper we introduce an efficient design that can provide fast and secure communication especially over the subsequent handover, we named it FSSHO for short, in our proposal we consider the use the of a pre-authentication scheme and prior backhaul inter-communication, our design generate a minimum delay that is more than suitable for real-time application. From our analytical comparison and simulation result we can see that our FSSHO approach achieves 72% improve over the standard and 38% improve over the enhanced scheme cited in the paper.

A Generic Analytical Modelling Approach for Performance Evaluation of the Handover Schemes in Heterogeneous Environments

In recent years, there has been an increased interest in the integration of different technologies in heterogeneous environments. Modelling heterogeneous systems is a complex task and handover schemes should consider issues such as network coverage, mobility, and Quality of Service (QoS). Analytical models are useful to deal with this complexity. This paper presents a generic framework to model handover in heterogeneous environments for performance evaluation of different handover schemes. The model developed considers mobility of the users, coverage radius of the networks as well as decision making probabilities about handover between the two networks. The interaction between cellular mobile technologies is considered and handover between a WLAN and a cellular system is analysed using the proposed model. Two stage open networks can be used to model this kind of integrated systems. The cellular mobile technologies are modelled as a multi-channel queuing system while the WLAN is depicted as a single channel queuing system, both with finite buffers. The exact spectral expansion method is employed to solve the models. Simulation is also employed for the proposed systems and used for validation of the accuracy of the proposed models. Numerical results are presented for mean queue length and blocking probabilities for each system. The results of this study show that QoS measures of such systems can be evaluated efficiently and accurately, using the proposed analytical model and its solution. In addition, it can be used as a framework in heterogeneous environments and can also be adapted to various types of networks in interaction.

An apropos signal report and adaptive period (ASAP) scheme for fast handover in the fourth-generation wireless networks

In this paper, a medium access control (MAC) layer handover scheme is proposed to reduce the handover processing time. Two critical points of investigation are examined to improve the performance of the handover process. The first point is the exact point of time when the handover process should be triggered. This factor is highly related to the signal-to-noise ratio (SNR) the mobile station (MS) receives at that moment. The second point is the moving direction and current moving velocity of the MS. Based on these two factors, an apropos signal report and adaptive period (ASAP) handover scheme is proposed to reduce the handover processing time. ASAP is based on the concept that the received SNR is highly related to the point of time the MS reports and the circumstance the MS stays. If the variation between two reported SNR values is large, the time interval of receiving the next SNR report must be reduced, or increased when the variation is small, to accurately reflect the SNR change. ASAP adjusts the periodic ranging period dynamically according to the MS moving velocity and no additional control messages are introduced into ASAP. ASAP is a base station (BS) initiated handover scheme. Detailed comparisons reveal that ASAP can achieve a handover delay reaching 15ms low at most, which is substantially smaller than the fastest legacy network-assisted handover mechanism (50ms).

Quality of Service during Handover in Heterogeneous Wireless Network

a cellular network, handoff is a process of transferring a mobile station (MS) from one base station (BS) or channel to another as the user is on the move. The handover process must take care of several parameters e.g. the handover scheme that is being used; number of free channels etc. The main objective of any handover scheme is to keep QoS up to the standard. If handover scheme fails, it leads to disruption or termination of an ongoing call which is not desirable. The quality of any network is defined by its Quality of Service (QOS) parameters and handoff scheme plays an important role in maintaining the standards of QOS. In this paper, when the user is on the move, the handoff mechanism is analyzed on the basis of received signal strength from two different base stations and results are plotted using the Matlab code.