Terms Of Handover Delay Research Articles

Mobility management of multi-hop mobile integrated access and backhaul network

As services and applications utilizing mobile networks grow exponentially, base station (BS) density becomes increasingly dense. There is an increasing demand for wireless backhaul technology for efficient deployment of high-density mobile networks. Although integrated access and backhaul (IAB) technology for efficient operation of wireless backhaul is attracting attention, consideration for mobile IAB (MIAB) is very insufficient. In this work, we propose a novel handover (HO) scheme for MIAB network to reduce handover interruption time (HIT) and radio link failure (RLF) that have a significant impact on users' quality of service (QoS). We investigate HO cases that cover intra-gNB HO, inter-gNB HO, and parent MIAB node HO, and develop their probabilistic models according to the velocities of parent MIAB node and child MIAB node. In addition, we investigate the latency in uplink (UP) control plane (CP) data transmission and each HO case for the baseline MIAB network. Our proposed HO scheme consists of low-latency UL CP data transmission with semi-persistent resource pre-allocation and RACH-less HO procedure for child MIAB nodes. Through simulation, we verify our proposed MIAB HO scheme outperforms the baseline HO scheme in terms of HO delay and HO overhead.

Exploring Software-Defined Network (SDN) for Seamless Handovers in Future Vehicular Networks

With the rapid development of communication technology, vehicular communications systems are evolving to Intelligent Transportation System (ITS) by providing its wireless network services with increasing demand for high data rate. However, the highly mobile feature of vehicles and varying network densities in such communication systems pose challenges for the mobility management, including frequent handovers, increased delay and failure of the handover process. In this work, we propose an optimized mobility management approach using Software-Defined Network (SDN) in the future vehicular networks. In addition, we have proposed a new handover management mechanism. This new mechanism allows vehicles to select the most optimal network based on multi-criteria metrics. The simulation results show that the proposed approach performs well and achieves an improvement in terms of handover delay and handover failure rate, compared to existing approach.

Efficient Handover Approach in 5G Mobile Networks

Femtocell technology has improved cellular coverage and capacity allowing the provision of rich and interactive communication services in current mobile networks. However, this technology suffers from several drawbacks including; increased interference and packet loss, frequent handovers, and high energy consumption. This paper presents a new handover management approach to overcome performance limitations linked to handover taking place at dense femtocell environments. RSSI of Base Station (BS), mobile user’s movement direction, and BS available capacity are factors used in this work to improve handover decision while sustaining perceived network performance. In addition, in order to reduce the complexity and delay of handover process, the proposed approach has redefined handover major phases including; preparation, decision and execution phases. A densely deployed simulated environment representing heterogeneous 4G and 5G architecture was implemented to evaluate the proposed approach. The simulation environment consists of three paths, each path represents a different network and mobility condition including BS distribution, obstacles, UE movement direction and distance. Results confirmed that the proposed handover approach reported an improved performance in terms of handover delay and number of unnecessary handovers. The average number of handovers occurred during all simulation scenarios was 3, also the average handover delay achieved was (55.15 ms). The number of handovers were decreased 30% and handover delay was reduced more than 10 ms comparing to conventional handover approaches such RSS-based. Hence, an improved adoption of handover management into femotocell environment.

Performance analysis of handover delay and buffer capacity in mobile OpenFlow‐based networks

SummarySoftware‐defined networking (SDN) is a network concept that brings significant benefits for the mobile cellular operators. In an SDN‐based core network, the average service time of an OpenFlow switch is highly influenced by the total capacity and type of the output buffer, which is used for temporary storage of the incoming packets. In this work, the main goal is to model the handover delay due to the exchange of OpenFlow‐related messages in mobile SDN networks. The handover delay is defined as the overall delay experienced by the mobile node within the handover procedure, when reestablishing an ongoing session from the switch in the source eNodeB to the switch in the destination eNodeB. We propose a new analytical model, and we compare two systems with different SDN switch designs that model a continuous time Markov process by using quasi‐birth–death processes: (1) single shared buffer without priority (model SFB), used for all output ports for both control and user traffic, and (2) two isolated buffers with priority (model priority finite buffering [PFB]), one for control and the other for user plane traffic, where the control traffic is always prioritized. The two proposed systems are compared in terms of total handover delay and minimal buffer capacity needed to satisfy a certain packet error ratio imposed by the link. The mathematical modeling is verified via extensive simulations. In terms of handover delay, the results show that the model PFB outperforms the model SFB, especially for networks with high number of users and high probability of packet‐in messages. As for the buffer dimensioning analysis, for lower arrival rates, low number of users, and low probability of packet‐in messages, the model SFB has the advantage of requiring a smaller buffer size.

RETRACTED ARTICLE: Fuzzy signal strength estimated Markov probabilistic graph for efficient handover and seamless data delivery in PAN

Seamless mobility management is an ability of the system to support the different services in personal area networks. A mobility management system is effectively designed for seamless mobile communication through the handover process. The handover is to transfer the data efficiently from one base station to another without any link failure. In order to improve the seamless data delivery with less handover delay, Fuzzy Signal Strength Estimation based on Stochastic Markov Graphical Model (FSSE-SMGM) is introduced in PAN. The PAN includes a number of mobile nodes. The mobile nodes are clustered in a more dynamic manner based on their communication range. Each cluster has a unique base station. When a mobile node moves out of its communication range, the centralized anchor node computes the Received Signal Strength (RSS) of the mobile nodes from the base station using two ray ground model. The model predicts the path losses between transmitting antenna and receiving antenna when they are in line of sight. FSSE-SMGM uses the fuzzy triangular membership function to evaluate the RSS with the threshold value. In addition, the direction angle’s degree of each mobile node from the current position towards the available base station is computed. Based on the signal strength and direction angle, the centralized anchor node switches the mobile node to the best available base station. Followed by, greater signaling cost is achieved during randomness nature over seamless mobility. After that, Stochastic Markov Graphical Model is used in FSSE-SMGM to improve the seamless data delivery through adjacent mobile nodes using state transition probability. The nodes with minimum distance are formed a chain with Markov property. This in turn minimizes the packet loss and ensures seamless data delivery between the mobile nodes. The simulations of proposed FSSE-SMGM and existing methods are carried out in terms of handover delay, seamless data delivery rate and data packet loss rate with respect to a number of data packets, and mobile speed. The simulation result shows that FSSE-SMGM improves the seamless data delivery rate and minimizes the data packet loss as well as handover delay.

Extension of MIH for FPMIPv6 (EMIH-FPMIPv6) to support optimized heterogeneous handover

Fast handover for Proxy Mobile IPv6 (FPMIPv6) can optimize the handover performance compared with PMIPv6 in terms of handover delay and packet loss. However, FPMIPv6 cannot handle heterogeneous handovers due to the lack of unified Layer 2 triggering mechanism. While Media Independent Handover (MIH) can provide heterogeneous handover support, and a lot of MIH-based integration solutions have been proposed. However, most of these solutions are based on the integration of MIH and PMIPv6, and require additional mechanisms such as L2 scanning, handover coordinator or neighbor discovery, which are out of the scope of MIH and difficult to be standardized. Furthermore, the direct integration of MIH and FPMIPv6 will cause redundant signaling cost due to the similar functions such as MIH handover commit procedure in MIH and inter-MAG (Mobility Access Gateway) tunnel setup in FPMIPv6. This paper provides a comprehensive survey on these solutions and compares each solution’s functionality and characteristic, and then proposes an integration scheme based on Extension of MIH for FPMIPv6 (EMIH-FPMIPv6) to support optimized heterogeneous handover, which extends the existing MIH standard and reduces the redundant messages interaction caused by FPMIPv6 and MIH. This paper adopts the city section mobility model and heterogeneous networks model to analyze and compare the performance of EMIH-FPMIPv6 under different heterogeneous handover scenarios. The analytical results show that EMIH-FPMIPv6 is capable of reducing the handover delay and the signaling cost compared to the solution specified in MIH standard (noted as standard handover solution) and FPMIPv6.

EMA-RPL: Energy and mobility aware routing for the Internet of Mobile Things

Internet of Mobile Things (IoMT) is a new paradigm of the Internet of Things (IoT) where devices are inherently mobile. While mobility enables innovative applications and allows new services, it remains a challenging issue as it causes disconnection of nodes and intermittent connectivity, which negatively impacts the network operation and performance. In addition, energy saving presents a real challenge for networks with limited resources. In this context, a new energy efficient and mobility aware routing protocol called EMA-RPL is proposed based on the well-known Routing Protocol for Low power and Lossy Networks (the RPL standard). Unlike the RPL which is basically designed for static devices, EMA-RPL enables better sustaining of connectivity of mobile nodes and conserving energy. The proposed protocol integrates an enhanced mobility detection method through a continuous control of the distance between the mobile node and its attachment, a novel point of attachment prediction based on the new location of the mobile node, and an efficient replacement strategy preserving the mobile node energy. EMA-RPL overcomes and mitigates problems caused by the mobility of nodes. Simulations using Cooja/Contiki show that EMA-RPL outperforms both the RPL and its mobility aware variant (MRPL) in terms of handover delay, data loss rate, signaling cost and energy consumption.

A Future Mobile Packet Core Network Based on Ip-In-Ip Protocol

The current Evolved Packet Core (EPC) 4th generation (4G) mobile network architecture features complicated control plane protocols and requires expensive equipment. Data delivery in the mobile packet core is performed based on a centralized mobility anchor between eNode B (eNB) elements and the network gateways. The mobility anchor is performed based on General Packet Radio Service tunnelling protocol (GTP), which has numerous drawbacks, including high tunnelling overhead and suboptimal routing between mobile devices on the same network. To address these challenges, here we describe new mobile core architecture for future mobile networks. The proposed scheme is based on IP encapsulated within IP (IP-in-IP) for mobility management and data delivery. In this scheme, the core network functions via layer 3 switching (L3S), and data delivery is implemented based on IP-in-IP routing, thus eliminating the GTP tunnelling protocol. For handover between eNB elements located near to one another, we propose the creation of a tunnel that maintains data delivery to mobile devices until the new eNB element updates the route with the gateway, which prevents data packet loss during handover. For this, we propose Generic Routing Encapsulation (GRE) tunnelling protocol. We describe the results of numerical analyses and simulation results showing that the proposed network core architecture provides superior performance compared with the current 4G architecture in terms of handover delay, tunnelling overhead and total transmission delay.

Handover performance analysis for managing D2D mobility in 5G cellular networks

Device-to-device (D2D) communication is seen as an important emerging technology and a hot research area for (5th Generation) cellular networks that takes advantage of the physical proximity of communicating devices. However, its implementation faces some technical issues such as interference management, resource allocation, mobility management, security and so on. Recently, many research works have tried to deal with those problems. In this study, the authors focus on D2D mobility management issue and they give a comparative study on the existing techniques in cellular networks managing the mobile devices (MDs) connections and maintaining service continuity when moving between coverage areas. First, they describe the different D2D handover management techniques. Second, through analysing and categorising a wide range of the latest research works on Distributed Mobility Management, they select some approaches that could be suitable for D2D mobility management in 5G cellular networks. Finally, they mathematically analyse the handover performance of the selected solutions, and compare them and they conclude that Software Defined Networking based solution outperforms the others in terms of handover delay, packet loss, ping-pong effect as well as the handover failure probability.

On the impact of mobile node radio architectures on heterogeneous wireless network standards: A performance analysis of LTE–eHRPD mobility

With the availability of various heterogeneous radio access technology standards, how to support multiple heterogeneous radio interfaces in a single device and provide seamless mobility between them is one of key issues in the design and implementation of modern multi-radio mobile devices (like smartphones). The radio architectures of such multi-radio mobile devices can have great impacts on achievable mobility performance. This paper presents a case study that investigates into the impacts of radio architecture design on mobility performance achievable in wireless standard implementation, with a particular focus on heterogeneous radio access mobility between Long Term Evolution (LTE) and enhanced High Rate Packet Data (eHRPD). We present an in-depth overview of handover procedures in standards and their achievable performance enhancements from the perspective of device radio architectures. We consider three radio architectures (single transmission/reception, single transmission dual reception, and dual transmission/reception architectures) and provide a performance analysis to compare the three architectures in terms of handover delay and energy consumption. We also discuss supportability for advanced flow-precision mobility under the different radio architectures, and present a comparison with another vertical handover technology.

Analysis of IEEE 802.21 media independent handover with mobility management protocols for handover optimization

The accessibility of different wireless access technologies has become an essential aspect of mobile communications. Integrating heterogeneous wireless networks should guarantee the best quality of service (QoS) and cooperation among all layers. Seamless service is achieved by an optimized handover decision. Hence, the IEEE 802.21 Media Independent Handover (MIH) standard provides sufficient information for handover operations across heterogeneous environments. The present work aims at the integration of available networks and analyzes user mobility behavior based on the IEEE 802.21 MIH standard and the cooperative Proxy Mobile IPv6 (PMIPv6) and Session Initiation Protocols (SIP) to assist fast handover operations. The handover performance metrics are compared with various existing mechanisms in terms of handover delay, packet loss, network load and different traffic classes. Simulation results prove that the combined PMIPv6-SIP protocol considerably minimize handover delay and improve the system throughput for both real-time and non-real-time QoS efficiency.

Fast Forced Handover Technique for Load Balancing in Mobile WiMAX for Real-time Applications

Mobile WiMAX is a wireless Metropolitan Area Network technology based on IEEE 802.16e standard which supports mobility for users. Huge number of mobile devices being used in WiMAX networks more than ever. However, these devices sustaining poor service quality and long delay due to network congestion. In order to solve these problems, a load balancing technique using Base Station (BS) initiated directed handover is proposed in this paper. The proposed technique called Fast Forced Handover Technique (FFHT). FFHT monitors the load-state in each BS and collect information about load-states of Neighbor BSs (NBSs). When congestion occurred at any BS, FFHT chooses Target BS (TBS). Furthermore, FFHT chooses candidate Mobile Stations to perform directed handover. In terms of handover delay, FFHT exchanges pre-handover control messages between serving BS (SBS) and NBSs to reduce delay and packet loss during handover process. FFHT is implemented using OPNET modeler 17.1. Its performance is evaluated based on an extensive simulation. The evaluation results demonstrate that the proposed technique distributes load efficiently in the whole network using light amount of control messages. FFHT assures Quality of Service (QoS) for all users in the network. The simulation shows how FFHT is suitable for real-time applications.

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.

A Context Transfer Model for Secure Handover in WiMAX/LTE Integrated Networks

One of the recent research issues in IP Multimedia Subsystem (IMS) based heterogeneous internetworking environment is to provide secure handover when a mobile node (MN) moves between different access networks. Various security schemes are available in literature but most of the schemes provide security but degrades the Quality of Service (QoS). The objective of this work is to provide secure and efficient handover in an IMS based Worldwide Interoperability for Microwave access (WiMAX)/ Long Term Evolution (LTE) integrated networks by using the proposed Secure Context Transfer Model (SCTM). New Session Initiation Protocol (SIP) messages are introduced in the proposed SCTM for transferring the context securely from old Proxy-Call session control function (P-CSCF) server to new P-CSCF server during handover. SCTM is verified using NS-2 simulator and analyzed based on Queuing theory. The results show that when compared with previous approaches, SCTM shows an improvement of 23% in terms of handover delay and packet loss providing security and guaranteed QoS to mobile users.

Cross layer based fast handover for IEEE 802.16e networks

To guarantee the QoS in real time applications in wireless networks, handover delay is one of the most important parameters to be considered while mobile users are changing their point of attachment to the access networks. This calls for a fast handover mechanism that will be able to offer uninterrupted services to mobile users. In this paper, a cross layer based fast handover mechanism is proposed to reduce handover delay and signaling load in IEEE 802.16e wireless metropolitan area networks. This is achieved by overlapping the functions of Medium Access Control (MAC) Layer and Internet Protocol (IP) layer. The analytical results show that the proposed mechanism significantly enhances the handover performance in terms of handover delay and signaling load thus resulting into fast handover.

EFLoM: An Efficient Framework for Local Mobility

In this paper, we propose a new framework: Efficient Framework for Local Mobility (EFLoM). EFLoM is developed to handle the issue of local mobility management. To enable MN to move across networks within one domain, EFLoM employs three network entities: Local Anchor Router (LAR), Wireless Access Gateway (WAG) and Mobile Node (MN). With the help of the three network entities, EFLoM can reduce the handover delay for MN. Moreover, EFLoM uses an IP header swapping mechanism to avoid the traffic overhead and improve the network’s throughput. To evaluate the performance of EFLoM, several experiments are carried out comparing EFLoM with Hierarchical Mobile IPv6 (HMIPv6) (Soliman et al., 2008) [1] and Proxy Mobile IPv6 (PMIPv6) (Gundavelli et al., 2008; Kempf, 2007a, 2007b; Vogt and Kempf, 2007) [2–5] – both of which are common local mobility management protocols – in terms of handover delay, throughput and signaling cost. Analysis and simulation results show good performance for EFLoM.

A Fast Authentication Scheme for WiMAX–WLAN Vertical Handover

In view that authentication has made a significant determinant in handover delay, this paper presents a fast authentication mechanism for mobile stations roaming within a WiMAX---WLAN interconnected environment. Incorporating a key reuse design that prevents repeated transactions at a remote server, our mechanism distributes security contexts ahead of handover to a local trusted key holder which manages several sites. A target site, upon receiving a mobile station, retrieves the contexts locally for authentication purpose and thus completes handover efficiently. While employing a target prediction algorithm as an option, our mechanism distributes the contexts to target candidates as dictated, which further improves handover performance if target prediction hits and maintains its advantage even in a miss. In addition, the handover optimization design specified in WiMAX is extended to support WiFi-to-WiMAX handovers. We reason that the proposed mechanism does not compromise the system in any sense as well. Analytical and simulation results show that, despite key pre-distribution misses, our mechanism leads to marked improvement over counterpart schemes in terms of handover delay and packet loss, meeting delay-sensitive application requirements.

고속 핸드오버를 위한 PFMIPv6와 무선랜의 효율적인 연동 방안

As the number of a smart phone user over the world surprisingly grows and a wireless Internet market expands, service requirement of a mobile terminal is increasing. However, because there is no consideration of mobility in the early standard step, it is difficult to expect to improve the service performance in handover procedure. This paper proposes a PFMIPv6 handover scheme by using probe request message and authentication message and by using buffering scheme in IEEE 802.11. In addition, we simulated this proposal scheme and verified that the proposed handover scheme is improved in terms of handover delay, and average FTP throughput during the handover period.

Handover approaches for seamless mobility management in next generation wireless networks

ABSTRACTNext generation wireless networks (NGWN) will be an integration of heterogeneous wireless access networks that will interwork over an IP‐based infrastructure. This all‐IP vision has led to the development of handover mechanisms to support seamless mobility for active network services among the different interworking wireless networks in order to ensure network access ubiquity in NGWN. These handover mechanisms need to ensure that mobile devices continue to receive ongoing communication without any noticeable disruption during handover events among the heterogeneous networks. This paper gives a qualitative and quantitative review of current handover approaches of IP mobility management protocols for NGWN with an objective to introduce a new way of further optimizing the handover performance. In particular, the paper focuses on handover approaches of mobile IPv6 (MIPv6) based mobility management protocols. Thus, the need, benefits, and limitations of these handover approaches are explored. Thereafter, dynamic handover coordination is introduced as a new viable solution that exploits the benefits and mitigates the limitations of these handover approaches hence improving handover performance in terms of handover delay, packet loss, and signaling overhead. Copyright © 2011 John Wiley & Sons, Ltd.

Enhancing PMIPv6 for Better Handover Performance among Heterogeneous Wireless Networks in a Micromobility Domain

This paper analyzes the reduction of handover delay in a network-based localized mobility management framework assisted by IEEE 802.21 MIH services. It compares the handover signaling procedures with host-based localized MIPv6 (HMIPv6), with network-based localized MIPv6 (PMIPv6), and with PMIPv6 assisted by IEEE 802.21 to show how much handover delay reduction can be achieved. Furthermore, the paper proposes and gives an in-depth analysis of PMIPv6 optimized with a handover coordinator (HC), which is a network-based entity, to further improve handover performance in terms of handover delay and packet loss while maintaining minimal signaling overhead in the air interface among converged heterogeneous wireless networks. Simulation and analytical results show that indeed handover delay and packet loss are reduced.