Modeling and Performance Evaluation of MANET Handover

A Mobile Ad Hoc Network (MANET) is an unstructured collection of wireless nodes that move arbitrarily and use multi-hop protocols to communicate between each other. There is not a predefined infrastructure in a MANET as there is in other types of wireless networks. Now days, MANET networks integrate with other networks, like the Internet, permitting ad hoc nodes to communicate with hosts placed in any part of the world. But the integration of MANETs with fixed infrastructures must be carefully studied to evaluate how it performs. In such integrated scenario, commonly known as Hybrid Ad Hoc Network, a MANET can be seen as an extension to the existing infrastructure, whose mobile nodes seamlessly communicate with hosts on the fixed network by forwarding packets throughout the gateways found on the edge that join both types of network. Connecting MANETs to the Internet does not come without difficulties. Ad hoc routing protocols work different than the regular routing protocols used on the Internet, and their interoperability becomes an important issue. But when MANETs integrate with the Internet, a more demanding challenge emerges if node mobility is considered. A moving node may lose registration with its current gateway, and may then need to register to a different gateway (a handover) to continue communicating. During a handover, any ongoing communication will be interrupted affecting network performance. In order to improve this performance, an IP mobility management protocol must be used. The main objective of this research is to develop a model that may be used to evaluate the performance of MANET handovers under different scenarios. Different issues about MANET integration with the Internet are considered: the IP mobility protocol implemented, the external route computation procedure, the type of ad hoc routing protocol used, and the gateway discovery approach used. For this evaluation, a mobile node in a MANET holding a communication with a correspondent node in the Internet roams to a different sub-network, having to change its registration to a different gateway. The different scenarios considered to evaluate the handover performance include the use of different types of MANET protocols, the use of different gateway discovery approaches, and the use of different versions of the Mobile IP protocol. During the research a review was made of the functioning conditions for the proposed scenario. Then, a handover model was proposed, which was used to develop some metrics that were later used to evaluate the MANET handover performance. This metrics are the broken communication time, the probability of handover failure, and the average communication interruption time. In all the results found, we could confirm that the proactive discovery approach has a better handover performance than the reactive discovery approach, which permit us to conclude that regardless the MANET routing protocol, and the Mobile IP version, the proactive agent discovery approach should be used in highly mobile scenarios, preferable, with the reactive routing protocol

Interoperabilidad dinámica de servicios mediante comunicaciones inalámbricas bluetooth en entornos urbanos y sistemas inteligentes de transporte

La evolución en la capacidad de los sistemas empotrados y, en particular, de aquellos sistemas embarcados en terminales móviles, hace posible que hoy en día puedan ofrecer servicios avanzados que antes sólo se concebían para redes y sistemas de mayor envergadura tales como PCs conectados a través de Internet. En el nuevo escenario de los servicios en movilidad las tecnologías inalámbricas juegan un papel fundamental, y se complementan con tecnologías procedentes de otros ámbitos, como el middleware, para dar soporte a los servicios. El uso de estas tecnologías en entornos urbanos y sistemas de transporte inteligente conlleva una serie de ventajas que se manifiestan, por ejemplo, en la posibilidad de ofrecer servicios dependientes del contexto o en la interoperabilidad de servicios. Entre esas tecnologías destacan Bluetooth, como base para las comunicaciones inalámbricas y CORBA, como plataforma middleware. Si bien, las características de ambas tecnologías son bastante adecuadas al tipo de entornos mencionado, es necesario acomenter ciertas adaptaciones que tengan en cuenta las particularidades y situaciones que se dan en estos entornos y que garanticen un correcto acceso a los servicios y una gestión inteligente de las conexiones. Sobre la base de Wireless CORBA, una de las iniciativas que une Bluetooth y CORBA, en esta Tesis se plantean modificaciones y se definen nuevos elementos que permiten su utilización en entornos urbanos y sistemas inteligentes de transporte. La definición del sistema se acompaña de estudios y recomendaciones que ayudan a optimizar el rendimiento en función del tipo de servicio y las condiciones del entorno. El sistema planteado supone una base común para el desarrollo de nuevos servicios, y prueba de ello lo constituyen las aplicaciones implementadas, que demuestran la viabilidad práctica del mismo

Mobile Ad Hoc Networks

Guiding readers through the basics of these rapidly emerging networks to more advanced concepts and future expectations, Mobile Ad hoc Networks: Current Status and Future Trends identifies and examines the most pressing research issues in Mobile Ad hoc Networks (MANETs). Containing the contributions of leading researchers, industry professionals, and academics, this forward-looking reference provides an authoritative perspective of the state of the art in MANETs. The book includes surveys of recent publications that investigate key areas of interest such as limited resources and the mobility of mobile nodes. It considers routing, multicast, energy, security, channel assignment, and ensuring quality of service. Also suitable as a text for graduate students, the book is organized into three sections: Fundamentals of MANET Modeling and Simulation—Describes how MANETs operate and perform through simulations and models Communication Protocols of MANETs—Presents cutting-edge research on key issues, including MAC layer issues and routing in high mobility Future Networks Inspired By MANETs—Tackles open research issues and emerging trends Illustrating the role MANETs are likely to play in future networks, this book supplies the foundation and insight you will need to make your own contributions to the field. It includes coverage of routing protocols, modeling and simulations tools, intelligent optimization techniques to multicriteria routing, security issues in FHAMIPv6, connecting moving smart objects to the Internet, underwater sensor networks, wireless mesh network architecture and protocols, adaptive routing provision using Bayesian inference, and adaptive flow control in transport layer using genetic algorithms

Mobile Ad Hoc Networks

Guiding readers through the basics of these rapidly emerging networks to more advanced concepts and future expectations, Mobile Ad hoc Networks: Current Status and Future Trends identifies and examines the most pressing research issues in Mobile Ad hoc Networks (MANETs). Containing the contributions of leading researchers, industry professionals, and academics, this forward-looking reference provides an authoritative perspective of the state of the art in MANETs. The book includes surveys of recent publications that investigate key areas of interest such as limited resources and the mobility of mobile nodes. It considers routing, multicast, energy, security, channel assignment, and ensuring quality of service. Also suitable as a text for graduate students, the book is organized into three sections: Fundamentals of MANET Modeling and Simulation—Describes how MANETs operate and perform through simulations and models Communication Protocols of MANETs—Presents cutting-edge research on key issues, including MAC layer issues and routing in high mobility Future Networks Inspired By MANETs—Tackles open research issues and emerging trends Illustrating the role MANETs are likely to play in future networks, this book supplies the foundation and insight you will need to make your own contributions to the field. It includes coverage of routing protocols, modeling and simulations tools, intelligent optimization techniques to multicriteria routing, security issues in FHAMIPv6, connecting moving smart objects to the Internet, underwater sensor networks, wireless mesh network architecture and protocols, adaptive routing provision using Bayesian inference, and adaptive flow control in transport layer using genetic algorithms