Enhanced bicasting and buffering

Includes abstract. Includes bibliographical references

Quality of service and mobility management in IP-based radio access networks

Master'sMASTER OF ENGINEERIN

Design of interface selection protocols for multi-homed wireless networks

This thesis was submitted for the degree of Doctor of Philosophy and was awarded by Brunel University on 10 December 2010.The IEEE 802.11/802.16 standards conformant wireless communication stations have multi-homing transmission capability. To achieve greater communication efficiency, multi-homing capable stations use handover mechanism to select appropriate transmission channel according to variations in the channel quality. This thesis presents three internal-linked handover schemes, (1) Interface Selection Protocol (ISP), belonging to Wireless Local Area Network (WLAN)- Worldwide Interoperability for Microwave Access (WiMAX) environment (2) Fast Channel Scanning (FCS) and (3) Traffic Manager (TM), (2) and (3) belonging to WiMAX Environment. The proposed schemes in this thesis use a novel mechanism of providing a reliable communication route. This solution is based on a cross-layer communication framework, where the interface selection module uses various network related parameters from Medium Access Control (MAC) sub-layer/Physical Layer (PHY) across the protocol suite for decision making at the Network layer. The proposed solutions are highly responsive when compared with existing multi-homed schemes; responsiveness is one of the key factors in the design of such protocols. Selected route under these schemes is based on the most up to date link-layer information. Therefore, such a route is not only reliable in terms of route optimization but it also fulfils the application demands in terms of throughput and delay. Design of ISP protocol use probing frames during the route discovery process. The 802.11 mandates the use of different rates for data transmission frames. The ISP-metric can be incorporated into various routing aspects and its applicability is determined by the possibility of provision of MAC dependent parameters that are used to determine the best path metric values. In many cases, higher device density, interference and mobility cause variable medium access delays. It causes creation of ‘unreachable zones’, where destination is marked as unreachable. However, by use of the best path metric, the destination has been made reachable, anytime and anywhere, because of the intelligent use of the probing frames and interface selection algorithm implemented. The IEEE 802.16e introduces several MAC level queues for different access categories, maintaining service requirement within these queues; which imply that frames from a higher priority queue, i.e. video frames, are serviced more frequently than those belonging to lower priority queues. Such an enhancement at the MAC sub-layer introduces uneven queuing delays. Conventional routing protocols are unaware of such MAC specific constraints and as a result, these factors are not considered which result in channel performance degradation. To meet such challenges, the thesis presents FCS and TM schemes for WiMAX. For FCS, Its solution is to improve the mobile WiMAX handover and address the scanning latency. Since minimum scanning time is the most important issue in the handover process. This handover scheme aims to utilize the channel efficiently and apply such a procedure to reduce the time it takes to scan the neighboring access stations. TM uses MAC and physical layer (PHY) specific information in the interface metric and maintains a separate path to destination by applying an alternative interface operation. Simulation tests and comparisons with existing multi-homed protocols and handover schemes demonstrate the effectiveness of incorporating the medium dependent parameters. Moreover, show that suggested schemes, have shown better performance in terms of end-to-end delay and throughput, with efficiency up to 40% in specific test scenarios

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

Design of interface selection protocols for multi-homed wireless networks

The IEEE 802.11/802.16 standards conformant wireless communication stations have multi-homing transmission capability. To achieve greater communication efficiency, multi-homing capable stations use handover mechanism to select appropriate transmission channel according to variations in the channel quality. This thesis presents three internal-linked handover schemes, (1) Interface Selection Protocol (ISP), belonging to Wireless Local Area Network (WLAN)- Worldwide Interoperability for Microwave Access (WiMAX) environment (2) Fast Channel Scanning (FCS) and (3) Traffic Manager (TM), (2) and (3) belonging to WiMAX Environment. The proposed schemes in this thesis use a novel mechanism of providing a reliable communication route. This solution is based on a cross-layer communication framework, where the interface selection module uses various network related parameters from Medium Access Control (MAC) sub-layer/Physical Layer (PHY) across the protocol suite for decision making at the Network layer. The proposed solutions are highly responsive when compared with existing multi-homed schemes; responsiveness is one of the key factors in the design of such protocols. Selected route under these schemes is based on the most up to date link-layer information. Therefore, such a route is not only reliable in terms of route optimization but it also fulfils the application demands in terms of throughput and delay. Design of ISP protocol use probing frames during the route discovery process. The 802.11 mandates the use of different rates for data transmission frames. The ISP-metric can be incorporated into various routing aspects and its applicability is determined by the possibility of provision of MAC dependent parameters that are used to determine the best path metric values. In many cases, higher device density, interference and mobility cause variable medium access delays. It causes creation of ‘unreachable zones’, where destination is marked as unreachable. However, by use of the best path metric, the destination has been made reachable, anytime and anywhere, because of the intelligent use of the probing frames and interface selection algorithm implemented. The IEEE 802.16e introduces several MAC level queues for different access categories, maintaining service requirement within these queues; which imply that frames from a higher priority queue, i.e. video frames, are serviced more frequently than those belonging to lower priority queues. Such an enhancement at the MAC sub-layer introduces uneven queuing delays. Conventional routing protocols are unaware of such MAC specific constraints and as a result, these factors are not considered which result in channel performance degradation. To meet such challenges, the thesis presents FCS and TM schemes for WiMAX. For FCS, Its solution is to improve the mobile WiMAX handover and address the scanning latency. Since minimum scanning time is the most important issue in the handover process. This handover scheme aims to utilize the channel efficiently and apply such a procedure to reduce the time it takes to scan the neighboring access stations. TM uses MAC and physical layer (PHY) specific information in the interface metric and maintains a separate path to destination by applying an alternative interface operation. Simulation tests and comparisons with existing multi-homed protocols and handover schemes demonstrate the effectiveness of incorporating the medium dependent parameters. Moreover, show that suggested schemes, have shown better performance in terms of end-to-end delay and throughput, with efficiency up to 40% in specific test scenarios.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

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

Mobility in IPv6

Masteroppgave i informasjons- og kommunikasjonsteknologi 2001 - Høgskolen i Agder, GrimstadIn the future it is expectable that the number of terminals with wireless access to network resources will be more and more widespread, and it is therefore necessary to integrate mobility support into future generation networks so that users can be online, even while in motion. The increasing use of Internet suggests that the Internet technology can be the best candidate for effective realization of future generation mobile systems. Mobile IP can offer the possibility for use of the mobile Internet in other ways than it is used in the standard wired environment, and may be the solution to increasing mobility demands. Due to this, mobility in IPv6 (MIPv6) is designed to be scalable, stable, efficient and secure, which are the factors considered important for this thesis. Scalable – The number of users are expected to be so many that MIPv6 is, according to its specification, designed to scale almost as well as Internet without mobility support integrated. This implies the elimination of triangle routing, currently a challenge in MIPv4, and also a reasonable amount of data that must be managed by the nodes involved in mobility. MIPv6 is also designed so that future extensions and modifications are possible by allowing further growth. Stable – For the adoption rate of this technology to high, the users must be able to depend on the services provided. At present the implementations shows that there are still a few more steps to take until necessary stability is offered, but product quality releases of MIPv6 is expected to be released sometime next year. The implementation tested in this thesis reflects transparent mobility as to simple higher-level applications such as telnet and http, but not real-time applications. The implementation described in this thesis had some initial problems with the procedures for Duplicate Address Detection (DAD), which shall guarantee that all addresses on any given IPv6 network is unique. Some improvements for DAD have therefore been proposed in order to get better solutions as to fault-handling procedures when DAD fails. Efficient – Base MIPv6 as used in our implementation does not provide the handover efficiency needed for all kinds of applications. Seen from a traditional Internet point of view, the services offered are of best effort quality. A future version of the Internet protocol must, however, be designed to support applications with greater demands to handover latencies, than what a best effort service level can provide. Thus, the handover latency must in these cases be so small that it goes within the boundaries for e.g. demanding real-time applications. Several solutions are proposed for this purpose, but the area of research is still very new and no proposal will be defined for still some time. It seems like the initial mobility deployment phase will be without support for these services, but the technology is very promising and will most likely be integrated as the use of MIPv6 advances. Secure – In a large mobile environment mobile nodes will not only require Internet access within their own domain. They will also probably visit foreign networks, and as known from GSM infrastructure today, this will not be free of charge. Service providers in foreign domains commonly require authorization to ensure a good business relationship with the client. This leads directly to authentication, and of course accounting (AAA). This AAA infrastructure should be in place before mobile Internet can be deployed worldwide

IEEE 802.21 in heterogeneous handover environments

Mestrado em Engenharia de Computadores e TelemáticaO desenvolvimento das capacidades tecnológicas dos terminais móveis, e das infra-estruturas que os suportam, potenciam novos cenários onde estes dispositivos munidos com interfaces de diferentes tecnologias vagueiam entre diferentes ambientes de conectividade. É assim necessário providenciar meios que facilitem a gestão de mobilidade, permitindo ao terminal ligar-se da melhor forma (i.e., optando pela melhor tecnologia) em qualquer altura. A norma IEEE 802.21 está a ser desenvolvida pelo Institute of Electrical and Electronics Engineers (IEEE) com o intuito de providenciar mecanismos e serviços que facilitem e optimizem handovers de forma independente da tecnologia. A norma 802.21 especifica assim um conjunto de mecanismos que potenciarão cenários como o descrito acima, tendo em conta a motivação e requerimentos apresentados por arquitecturas de redes futuras, como as redes de quarta geração (4G). Esta dissertação apresenta uma análise extensiva da norma IEEE 802.21, introduzindo um conjunto de simulações desenvolvidas para estudar o impacto da utilização de mecanismos 802.21 em handovers controlados por rede, numa rede de acesso mista composta por tecnologias 802.11 e 3G. Os resultados obtidos permitiram verificar a aplicabilidade destes conceitos a ambientes de próxima geração, motivando também uma descrição do desenho de integração de mecanismos 802.21 a arquitecturas de redes de quarta geração. ABSTRACT: The development of the technological capabilities of mobile terminals, and the infra-structures that support them, enable new scenarios where these devices using different technology interfaces roam in different connectivity environments. This creates a need for providing the means that facilitate mobility management, allowing the terminal to connect in the best way possible (i.e., by choosing the best technology) at any time. The IEEE 802.21 standard is being developed by the Institute of Electrical and Electronics Engineers (IEEE) to provide mechanisms and services supporting Media Independent Handovers. The 802.21 standard specifies a set of mechanisms that enable scenarios like the one described above, considering the motivation and requirements presented by future network architectures, such as the ones from fourth generation networks (4G). This thesis presents an extensive analysis of the IEEE 802.21 standard, introducing a set of simulations developed for studying the impact of using 802.21 mechanisms in network controlled handovers, in a mixed access network composed of 802.11 and 3G technologies. The obtained results allow the verification of the applicability of these concepts into next generation environments, also motivating the description of the design for integration of 802.21 mechanisms to fourth generation networks