Modeling Seamless Vertical Handovers in Heterogeneous Wireless Networks

Vertical handover in heterogeneous wireless networks provides customers with better Quality of Service (QoS) experience. For seamless handover, timely initiation of handover process plays a key role. Various vertical handover management protocols have been proposed and standardized to support mobility across heterogeneous networks. In Media Independent Handover (MIH) based schemes, distributed handover decision is made via certain predefined triggers that consider user context. In this paper, we present a comprehensive review of the modeling techniques used during management of vertical handover. We have also defined a novel architecture, HRPNS: Handoff Resolving and Preferred Network Selection module enabling vertical handover that ensures QoS. The construction of HRPNS module involves integration of fuzzy logic and Markov Decision Process (MDP) for providing precise decision of handover

SCALABLE AND EFFICIENT VERTICAL HANDOVER DECISION ALGORITHMS IN VEHICULAR NETWORK CONTEXTS

A finales de los años noventa, y al comienzo del nuevo milenio, las redes inalámbricas han evolucionado bastante, pasando de ser sólo una tecnología prometedora para convertirse en un requisito para las actividades cotidianas en las sociedades desarrolladas. La infraestructura de transporte también ha evolucionado, ofreciendo comunicación a bordo para mejorar la seguridad vial y el acceso a contenidos de información y entretenimiento. Los requisitos de los usuarios finales se han hecho dependientes de la tecnología, lo que significa que sus necesidades de conectividad han aumentado debido a los diversos requisitos de las aplicaciones que se ejecutan en sus dispositivos móviles, tales como tabletas, teléfonos inteligentes, ordenadores portátiles o incluso ordenadores de abordo (On-Board Units (OBUs)) dentro de los vehículos. Para cumplir con dichos requisitos de conectividad, y teniendo en cuenta las diferentes redes inalámbricas disponibles, es necesario adoptar técnicas de Vertical Handover (VHO) para cambiar de red de forma transparente y sin necesidad de intervención del usuario. El objetivo de esta tesis es desarrollar algoritmos de decisión (Vertical Handover Decision Algorithms (VHDAs)) eficientes y escalables, optimizados para el contexto de las redes vehiculares. En ese sentido se ha propuesto, desarrollado y probado diferentes algoritmos de decisión basados en la infraestructura disponible en las actuales, y probablemente en las futuras, redes inalámbricas y redes vehiculares. Para ello se han combinado diferentes técnicas, métodos computacionales y modelos matemáticos, con el fin de garantizar una conectividad apropiada, y realizando el handover hacia las redes más adecuadas de manera a cumplir tanto con los requisitos de los usuarios como los requisitos de las aplicaciones. Con el fin de evaluar el contexto, se han utilizado diferentes herramientas para obtener información variada, como la disponibilidad de la red, el estado de la red, la geolocalizaciónMárquez Barja, JM. (2012). SCALABLE AND EFFICIENT VERTICAL HANDOVER DECISION ALGORITHMS IN VEHICULAR NETWORK CONTEXTS [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/17869Palanci

Mobility management across converged IP-based heterogeneous access networks

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University, 8/2/2010.In order to satisfy customer demand for a high performance “global” mobility service, network operators (ISPs, carriers, mobile operators, etc.) are facing the need to evolve to a converged “all-IP” centric heterogeneous access infrastructure. However, the integration of such heterogeneous access networks (e.g. 802.11, 802.16e, UMTS etc) brings major mobility issues. This thesis tackles issues plaguing existing mobility management solutions in converged IP-based heterogeneous networks. In order to do so, the thesis firstly proposes a cross-layer mechanism using the upcoming IEEE802.21 MIH services to make intelligent and optimized handovers. In this respect, FMIPv6 is integrated with the IEEE802.21 mechanism to provide seamless mobility during the overall handover process. The proposed solution is then applied in a simulated vehicular environment to optimize the NEMO handover process. It is shown through analysis and simulations of the signalling process that the overall expected handover (both L2 and L3) latency in FMIPv6 can be reduced by the proposed mechanism by 69%. Secondly, it is expected that the operator of a Next Generation Network will provide mobility as a service that will generate significant revenues. As a result, dynamic service bootstrapping and authorization mechanisms must be in place to efficiently deploy a mobility service (without static provisioning), which will allow only legitimate users to access the service. A GNU Linux based test-bed has been implemented to demonstrate this. The experiments presented show the handover performance of the secured FMIPv6 over the implemented test-bed compared to plain FMIPv6 and MIPv6 by providing quantitative measurements and results on the quality of experience perceived by the users of IPv6 multimedia applications. The results show the inclusion of the additional signalling of the proposed architecture for the purpose of authorization and bootstrapping (i.e. key distribution using HOKEY) has no adverse effect on the overall handover process. Also, using a formal security analysis tool, it is shown that the proposed mechanism is safe/secure from the induced security threats. Lastly, a novel IEEE802.21 assisted EAP based re-authentication scheme over a service authorization and bootstrapping framework is presented. AAA based authentication mechanisms like EAP incur signalling overheads due to large RTTs. As a result, overall handover latency also increases. Therefore, a fast re-authentication scheme is presented which utilizes IEEE802.21 MIH services to minimize the EAP authentication process delays and as a result reduce the overall handover latency. Analysis of the signalling process based on analytical results shows that the overall handover latency for mobility protocols will be approximately reduced by 70% by the proposed scheme

IP-Based Mobility Management and Handover Latency Measurement in heterogeneous environments

One serious concern in the ubiquitous networks is the seamless vertical handover management between different wireless technologies. To meet this challenge, many standardization organizations proposed different protocols at different layers of the protocol stack. The Internet Engineering Task Force (IETF) has different groups working on mobility at IP level in order to enhance mobile IPv4 and mobile IPv6 with different variants: HMIPv6 (Hierarchical Mobile IPv6), FMIPv6 (Fast Mobile IPv6) and PMIPv6 (Proxy Mobile IPv6) for seamless handover. Moreover, the IEEE 802.21 standard provides another framework for seamless handover. The 3GPP standard provides the Access Network and Selection Function (ANDSF) to support seamless handover between 3GPP – non 3GPP networks like Wi-Fi, considered as untrusted, and WIMAX considered as trusted networks. In this paper, we present an in-depth analysis of seamless vertical handover protocols and a handover latency comparison of the main mobility management approaches in the literature. The comparison shows the advantages and drawbacks of every mechanism in order to facilitate the adoption of the convenient one for vertical handover within Next Generation Network (NGN) environments. Keywords: Seamless vertical handover, mobility management protocols, IEEE 802.21 MIH, handover latenc

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. © 201

A network-based coordination design for seamless handover between heterogeneous wireless networks

Includes bibliographical references (leaves 136-144).The rapid growth of mobile and wireless communication over the last few years has spawned many different wireless networks. These heterogeneous wireless networks are envisioned to interwork over an IP-based infrastructure to realize ubiquitous network service provisioning for mobile users. Moreover, the availability of multiple-interface mobile nodes (MNs) will make it possible to communicate through any of these wireless access networks. This wireless network heterogeneity combined with the availability of multiple-interface MNs creates an environment where handovers between the different wireless access technologies become topical during mobility events. Therefore, operators with multiple interworking heterogeneous wireless networks will need to facilitate seamless vertical handovers among their multiple systems. Seamless vertical handovers ensure ubiquitous continuity to active connections hence satisfy the quality of experience of the mobile users

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

Network-Assisted Handover for Heterogeneous Wireless Networks using IEEE 802.21

The IEEE 802.21 is a standard for enabling handover in heterogeneous wireless networks. Published in January 2009, it defines protocols and messages for mobile-to-node and node-to-node communication in a technology-neutral and flexible manner. The need arises because of the widespread diffusion of different technologies for wireless communications (e.g., WiFi, WiMAX, LTE) coexisting in the same geographical area. Even though the number of multi-radio multi-technology mobile devices is increasing significantly, there are no open solutions in the market to enable efficient inter-technology handover. As is often the case with communication standards, the structure of the required components, the procedures, and the algorithms are left unspecified by the IEEE 802.21 standard so as to promote competion by differentiation of equipment capabilities and services. The contribution of this thesis is two-fold: i) a design and an implemenation of the Media Independent Information Service (MIIS) server; and, ii) a solution to enable network-assisted handover using the IEEE 802.21 standard, aimed at reducing the handover latency and the energy consumption of mobile devices due to scanning. The MIIS server has been fully implemented in C++ under Linux. In order to perform testbed evaluations, all the required components have been implemented, as well, within an open source framework for IEEE 802.21 called ODTONE. Modifications to the latter have been performed for optimization and fine tuning, and for extending those functional modules needed but not fully implemented. For a realistic evaluation, Linux-based embedded COTS devices have been used, equipped with multiple IEEE 802.11a and IEEE 802.11g wireless network interface cards. This has required additional development for kernel/user space binding and hardware control. Testbed results are reported to show the effectiveness of the proposed solution, also proving the MIIS server scalability

Client-based SBM layer for predictive management of traffic flows in heterogeneous networks

In a heterogeneous networking environment, the knowledge of the time before a vertical handover (TBVH) for any network is vital in correctly assigning connections to available channels. In this paper, we introduce a predictive mathematical model for calculating the estimated TBVH component from available network parameters and discuss the different scenarios that arise based on a mobile host’s trajectory. We then introduce the concept of an intelligent Stream Bundle Management Layer (SBM) which consists of a set of policies for scheduling and mapping prioritised traffic streams on to available channels based on their priority, device mobility pattern and prevailing channel conditions. The layer is also responsible for the maintenance of connections during vertical handovers to avoid their forced termination