Prediction assisted fast handovers for seamless IP mobility

Word processed copy.Includes bibliographical references (leaves 94-98).This research investigates the techniques used to improve the standard Mobile IP handover process and provide proactivity in network mobility management. Numerous fast handover proposals in the literature have recently adopted a cross-layer approach to enhance movement detection functionality and make terminal mobility more seamless. Such fast handover protocols are dependent on an anticipated link-layer trigger or pre-trigger to perform pre-handover service establishment operations. This research identifies the practical difficulties involved in implementing this type of trigger and proposes an alternative solution that integrates the concept of mobility prediction into a reactive fast handover scheme

An Overview of Mobile Ad Hoc Networks for the Existing Protocols and Applications

Mobile Ad Hoc Network (MANET) is a collection of two or more devices or nodes or terminals with wireless communications and networking capability that communicate with each other without the aid of any centralized administrator also the wireless nodes that can dynamically form a network to exchange information without using any existing fixed network infrastructure. And it's an autonomous system in which mobile hosts connected by wireless links are free to be dynamically and some time act as routers at the same time, and we discuss in this paper the distinct characteristics of traditional wired networks, including network configuration may change at any time, there is no direction or limit the movement and so on, and thus needed a new optional path Agreement (Routing Protocol) to identify nodes for these actions communicate with each other path, An ideal choice way the agreement should not only be able to find the right path, and the Ad Hoc Network must be able to adapt to changing network of this type at any time. and we talk in details in this paper all the information of Mobile Ad Hoc Network which include the History of ad hoc, wireless ad hoc, wireless mobile approaches and types of mobile ad Hoc networks, and then we present more than 13 types of the routing Ad Hoc Networks protocols have been proposed. In this paper, the more representative of routing protocols, analysis of individual characteristics and advantages and disadvantages to collate and compare, and present the all applications or the Possible Service of Ad Hoc Networks.Comment: 24 Pages, JGraph-Hoc Journa

Media independent handovers : network selection for mobile IP nodes in heterogeneous wireless networks

Includes abstract.Includes bibliographical references (p. 79-82).In Next Generation Networks (NGN), also known as 4G, Beyond 3G, Converged, Integrated and Interworked Network, user node mobility in wireless and wired environments will seamlessly cross disparate network boundaries. The effort to offer ubiquitous computing, providing access to services anywhere and anytime, strongly encourages the ability to roam across the different existing and future networks. Literature shows investigation of concepts such as Always Best Connected (ABC) when heterogeneous networks co-exist , which will work or compete with other schemes like Home Network Default (HND), Compatibility and Network Operator Agreements (CNOA) to guide network selection or access . With the variety of available networks, the mobile node may be faced with having to decide which network to connect to. We concentrate on the network selection aspects of these envisaged mobile, overlay and integrated environment in heterogeneous networks. The standard developments by the IEEE802.21 Working group and the IETF Networking group form the base of our approach that seeks to see mobility across heterogeneous networks a reality. We propose an IEEE802.21 Media Independent Handover Function (MIHF) based network discovery and network selection, leading to a handover. The selection may be further assisted by an MIHF capable Broker Node that is Third party to the Network Providers to provide a central yet distributed database of the available networks as encountered by the Mobile Node, to cater for Nodes with no prior knowledge of networks and software repository. A Mobile Node (MN) in our solution uses 802.21 communication messages to obtain information about foreign networks encountered before selecting the networks to connect to. Our evaluation through simulations, shows that network selection in heterogeneous wireless networks environment for the appropriately equipped devices is greatly enhanced by the use of the Media Independent Handover Protocol. In scenarios where the mobile node has no prior knowledge of the encountered different network architectures, the use of a Broker node can, for an optimal number of available networks also greatly enhance the mobile node’s network selection by reducing the delay associated and the packet losses incurred

Dynamic wireless mobile framework for distributed collaborative real-time information generation and control systems

Intelligent Transportation Systems (ITS) have only recently discovered the exciting possibilities in the nomadic and ubiquitous computing space to build a new generation of information systems by allowing the vehicle to act both as a carrier and consumer of wireless (and thus omnipresent) information. Wide deployment of such ITS systems may eventually allow for more dynamic and efficient transportation systems, which can contribute in several ways towards greater economic growth whilst respecting environmental sustainability. A great number of researchers have dedicated considerable time and resources to tackling traffic related issues by utilising the new wireless capabilities enabled by ITS; such initiatives cover a wide range of applications such as safety, knowledge sharing and infotainment. Indicative of the extent of such efforts is the plethora of research projects initiated by many national and multi-national organisations such as the EU Framework Programme for Research and Technological Development. To achieve their goals, proposed solutions from such organisations depend on the development and deployment of intelligent wireless mobile communication systems, where data dissemination issues make the prospect of efficient and effective communication a challenging proposition. Presently, Car-to-Car and Car-to-Infrastructure communications are two distinct avenues that make possible efficient and reliable delivery of messages via direct radio links in traffic areas. In all cases, high quality of communication performance is desirable for a communication system composed mostly of roaming participants; such a system needs to be dynamic, flexible and infrastructure-less. Consequently, Mobile Ad hoc Network (MANET)-based networks are a natural fit to ITS

Seamless Hand-over Algorithm for Wireless Enterprise Networks

Masteroppgave i informasjons- og kommunikasjonsteknologi 2007 – Høgskolen i Agder, GrimstadThe mass deployment of the Institute of Electrical and Electronics Engineers’ (IEEE) 802.11 based wireless local area networks (WLAN) and increased sales in hand-held devices supporting WLAN have resulted in an urgent need to support fast WLAN handovers or roaming. The reason for this problem arising now is that hand-held devices are more mobile than a laptop and their users actively use their hand-held equipment while moving. Laptop users are often called nomadic users in contrast to the real mobile users. The customarily solution is that when a connection is lost with the associated access point, one tries to find a new access point and tries to connect to it. The process of finding a new access point and connecting to it takes too long time in current implementations. Some applications cannot tolerate to be interrupted or disconnected for a very long time period before the session breaks. Therefore we need mechanisms to make sure that the disconnection time is as low as possible. Our algorithm uses an improved threshold scheme to detect the handover. The algorithm avoids many unnecessary handovers and prevents rapidly dropped signal strength or poor connection quality. In addition, we do scanning and AP selection before critical situations occur and therefore are faster in disconnecting from the current AP. As a result, the whole disconnection time is only the handover execution time, which is much shorter than the customarily one’s. Furthermore, we use signal strength, hysteresis and trends to classify the candidate APs. The result allows us to choose the best one of them and then switch to it. Through thresholds and hysteresis based decisions we avoid the latent unnecessary handovers resulting in a undesired “yoyo” effect, where the client continuously jumps back and forth between APs. Our handover algorithm is signal strength based. For technical reasons, the signal strength is the main parameter we considered. In the future, several other quality parameters can be implemented into our algorithm to make the algorithm even more efficient, e.g., by querying APs about their current load and QoS resources

SIP-based proactive and adaptive mobility management framework for heterogeneous networks

Abstract In this paper, we present and evaluate the performance of a mobility management system called the Proactive and Adaptive Handover (PAHO) system. PAHO is an application-level approach that uses SIP to manage client-initiated connection handoff across heterogeneous networks based on the IEEE 802.21 framework with designated user/configuration policy. Unlike conventional systems which make sub-optimal decision when managing connection handoff due to limited awareness of the relevant context for the application/service being delivered, PAHO defines proper interface to interact with the application as to determine when and to where the handoff and/or codec switching should take place in the event of network performance degradation. The results showed that using the PAHO approach on an audio/video conferencing session helps reducing the overall handover delay from 10.766 s (on non-PAHO system) down to at least 288 ms, and slowing down the degradation of MOS value throughout the entire experiment in the event of signal degradation as well as network congestion. It is also shown that load balancing among the access points (AP) could be achieved with an improved Information Server (IS). r 2007 Elsevier Ltd. All rights reserved

Supporting Internet Access and Quality of Service in Distributed Wireless Ad Hoc Networks

In this era of wireless hysteria, with continuous technological advances in wireless communication and new wireless technologies becoming standardized at a fast rate, we can expect an increased interest for wireless networks, such as ad hoc and mesh networks. These networks operate in a distributed manner, independent of any centralized device. In order to realize the practical benefits of ad hoc networks, two challenges (among others) need to be considered: distributed QoS guarantees and multi-hop Internet access. In this thesis we present conceivable solutions to both of these problems. An autonomous, stand-alone ad hoc network is useful in many cases, such as search and rescue operations and meetings where participants wish to quickly share information. However, an ad hoc network connected to the Internet is even more desirable. This is because Internet plays an important role in the daily life of many people by offering a broad range of services. In this thesis we present AODV+, which is our solution to achieve this network interconnection between a wireless ad hoc network and the wired Internet. Providing QoS in distributed wireless networks is another challenging, but yet important, task mainly because there is no central device controlling the medium access. In this thesis we propose EDCA with Resource Reservation (EDCA/RR), which is a fully distributed MAC scheme that provides QoS guarantees by allowing applications with strict QoS requirements to reserve transmission time for contention-free medium access. Our scheme is compatible with existing standards and provides both parameterized and prioritized QoS. In addition, we present the Distributed Deterministic Channel Access (DDCA) scheme, which is a multi-hop extension of EDCA/RR and can be used in wireless mesh networks. Finally, we have complemented our simulation studies with real-world ad hoc and mesh network experiments. With the experience from these experiments, we obtained a clear insight into the limitations of wireless channels. We could conclude that a wise design of the network architecture that limits the number of consecutive wireless hops may result in a wireless mesh network that is able to satisfy users’ needs. Moreover, by using QoS mechanisms like EDCA/RR or DDCA we are able to provide different priorities to traffic flows and reserve resources for the most time-critical applications

Design of a UMTS/GPRS Assisted Mesh Network (UAMN)

Wireless Mesh or multi-hop networks (WMNs) are well known thanks to its simplicity on deployment and the lack of infrastructure. These two advantages come with some drawbacks. WMNs have limitations with the support of Quality of Service (QoS), they do not assure coverage or even connectivity, and security, management and monitoring are not considered key requirements. In order to benefit of mesh networks and use them as an operator graded network, it is necessary to either improve mesh networks to fulfill all these requirements or use an alternative network that offers full availability, connectivity and security to assist the mesh network. Considering the two options, the second is the one selected making use of GPRS/UMTS as an assistant network. The document describes a set of requirements and the design of the functionalities needed to build an operator graded network using the cellular GPRS/UMTS. The aspects covered in the design are: security, quality of service, mobility, self configuration and optimization. The last point, optimization, is not directly involved with mesh networking, but it is an improvement easy to achieve when using a gateway node to access the Internet through a GPRS/UMTS connection. The design of the solution not only considers functionality, but also feasibility employing of the shelve elements. The mesh nodes and gateways are built on top of Linux operating system with the aim to reuse previous results and open source software. The final objective of the project is to build a usable system to be used as a proof of concept.Peer Reviewe

Fast and seamless mobility management in IPV6-based next-generation wireless networks

Introduction -- Access router tunnelling protocol (ARTP) -- Proposed integrated architecture for next generation wireless networks -- Proposed seamless handoff schemes in next generation wireless networks -- Proposed fast mac layer handoff scheme for MIPV6/WLANs

Security and mobility in 802.11 structured networks

Mestrado em Engenharia Electrónica e TelecomunicaçõesNesta tese é apresentado um protocolo que permite handovers rápidos e seguros em redes estruturadas 802.11. Este protocolo recupera o paradigma original do 802.11: autenticar primeiro, reassociar depois. Partindo deste paradigma, apresentamos duas novas operações 802.11 de autenticação e (re)associacão, que permitem que uma estacão móvel realize reautenticacões e reassociações com as mesmas funcionalidades do 802.1X. Esta nova aproxiamação requer pouca mudança na arquitectura da rede, nomeadamente só necessita de um novo Servidor de Reautenticação, para armazenar os dados usados pelas estações móveis durante as reautenticações. Nesta tese é também apresentada uma extensão do nosso protocolo, de maneira a permitir uma migração rápida e segura entre ESS usando Mobile IP. ABSTRACT: This thesis presents a fast, secure handover protocol that recovers the original 802.11 paradigm: authenticate first, reassociate next. Following this paradigm, we present two new 802.11 authentication and (re)association operations which allow a mobile station to perform network reauthentications and reassociations with the same functionality of a complete 802.1X authentication. This new approach requires very little from the environment, namely it only requires a new, central network Reauthentication Service, for storing data used in the reauthentication of stations. This thesis also presents a layer 3 extension of our protocol, to support fast, secure transitions between ESS using Mobile IP