424 research outputs found
Architectural and mobility management designs in internet-based infrastructure wireless mesh networks
Wireless mesh networks (WMNs) have recently emerged to be a cost-effective solution to support large-scale wireless Internet access. They have numerous ap- plications, such as broadband Internet access, building automation, and intelligent transportation systems. One research challenge for Internet-based WMNs is to design efficient mobility management techniques for mobile users to achieve seamless roam- ing. Mobility management includes handoff management and location management. The objective of this research is to design new handoff and location management techniques for Internet-based infrastructure WMNs.
Handoff management enables a wireless network to maintain active connections as mobile users move into new service areas. Previous solutions on handoff manage- ment in infrastructure WMNs mainly focus on intra-gateway mobility. New handoff issues involved in inter-gateway mobility in WMNs have not been properly addressed. Hence, a new architectural design is proposed to facilitate inter-gateway handoff man- agement in infrastructure WMNs. The proposed architecture is designed to specifi- cally address the special handoff design challenges in Internet-based WMNs. It can facilitate parallel executions of handoffs from multiple layers, in conjunction with a data caching mechanism which guarantees minimum packet loss during handoffs. Based on the proposed architecture, a Quality of Service (QoS) handoff mechanism is also proposed to achieve QoS requirements for both handoff and existing traffic before and after handoffs in the inter-gateway WMN environment.
Location management in wireless networks serves the purpose of tracking mobile users and locating them prior to establishing new communications. Existing location management solutions proposed for single-hop wireless networks cannot be directly applied to Internet-based WMNs. Hence, a dynamic location management framework
in Internet-based WMNs is proposed that can guarantee the location management performance and also minimize the protocol overhead. In addition, a novel resilient location area design in Internet-based WMNs is also proposed. The formation of the location areas can adapt to the changes of both paging load and service load so that the tradeoff between paging overhead and mobile device power consumption can be balanced, and at the same time, the required QoS performance of existing traffic is maintained. Therefore, together with the proposed handoff management design, efficient mobility management can be realized in Internet-based infrastructure WMNs
Implementation and evaluation of the sensornet protocol for Contiki
Sensornet Protocol (SP) is a link abstraction layer between the network layer and the link layer for sensor networks. SP was proposed as the core of a future-oriented sensor node architecture that allows flexible and optimized combination between multiple coexisting protocols. This thesis implements the SP sensornet protocol on the Contiki operating system in order to: evaluate the effectiveness of the original SP services; explore further requirements and implementation trade-offs uncovered by the original proposal. We analyze the original SP design and the TinyOS implementation of SP to design the Contiki port. We implement the data sending and receiving part of SP using Contiki processes, and the neighbor management part as a group of global routines. The evaluation consists of a single-hop traffic throughput test and a multihop convergecast test. Both tests are conducted using both simulation and experimentation. We conclude from the evaluation results that SP's link-level abstraction effectively improves modularity in protocol construction without sacrificing performance, and our SP implementation on Contiki lays a good foundation for future protocol innovations in wireless sensor networks
EFFICIENT DYNAMIC ADDRESSING BASED ROUTING FOR UNDERWATER WIRELESS SENSOR NETWORKS
This thesis presents a study about the problem of data gathering in the inhospitable
underwater environment. Besides long propagation delays and high error probability,
continuous node movement also makes it difficult to manage the routing information
during the process of data forwarding. In order to overcome the problem of large
propagation delays and unreliable link quality, many algorithms have been proposed
and some of them provide good solutions for these issues, yet continuous node
movements still need attention. Considering the node mobility as a challenging task,
a distributed routing scheme called Hop-by-Hop Dynamic Addressing Based (H2-
DAB) routing protocol is proposed where every node in the network will be assigned
a routable address quickly and efficiently without any explicit configuration or any
dimensional location information. According to our best knowledge, H2-DAB is first
addressing based routing approach for underwater wireless sensor networks
(UWSNs) and not only has it helped to choose the routing path faster but also
efficiently enables a recovery procedure in case of smooth forwarding failure. The
proposed scheme provides an option where nodes is able to communicate without
any centralized infrastructure, and a mechanism furthermore is available where
nodes can come and leave the network without having any serious effect on the rest
of the network. Moreover, another serious issue in UWSNs is that acoustic links are
subject to high transmission power with high channel impairments that result in
higher error rates and temporary path losses, which accordingly restrict the
efficiency of these networks. The limited resources have made it difficult to design a
protocol which is capable of maximizing the reliability of these networks. For this
purpose, a Two-Hop Acknowledgement (2H-ACK) reliability model where two
copies of the same data packet are maintained in the network without extra burden
on the available resources is proposed. Simulation results show that H2-DAB can
easily manage during the quick routing changes where node movements are very
frequent yet it requires little or no overhead to efficiently complete its tasks
Software-Driven and Virtualized Architectures for Scalable 5G Networks
In this dissertation, we argue that it is essential to rearchitect 4G cellular core networks–sitting between the Internet and the radio access network–to meet the scalability, performance, and flexibility requirements of 5G networks. Today, there is a growing consensus among operators and research community that software-defined networking (SDN), network function virtualization (NFV), and mobile edge computing (MEC) paradigms will be the key ingredients of the next-generation cellular networks. Motivated by these trends, we design and optimize three core network architectures, SoftMoW, SoftBox, and SkyCore, for different network scales, objectives, and conditions. SoftMoW provides global control over nationwide core networks with the ultimate goal of enabling new routing and mobility optimizations. SoftBox attempts to enhance policy enforcement in statewide core networks to enable low-latency, signaling-efficient, and customized services for mobile devices. Sky- Core is aimed at realizing a compact core network for citywide UAV-based radio networks that are going to serve first responders in the future. Network slicing techniques make it possible to deploy these solutions on the same infrastructure in parallel. To better support mobility and provide verifiable security, these architectures can use an addressing scheme that separates network locations and identities with self-certifying, flat and non-aggregatable address components. To benefit the proposed architectures, we designed a high-speed and memory-efficient router, called Caesar, for this type of addressing schemePHDComputer Science & EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/146130/1/moradi_1.pd
The design and performance evaluation of a proactive multipath routing protocol for mobile ad hoc networks
Due to unpredictable network topology changes, routing in Mobile Ad Hoc Networks
(MANET) is an important and challenging research area. The routing protocol
should detect and maintain a good route(s) between source and destination nodes in
these dynamic networks. Many routing protocols have been proposed for mobile ad
hoc networks, and none can be considered as the best under all conditions.
This thesis presents the design and implementation of a new proactive multipath
MANET routing protocol. The protocol, named Multipath Destination Sequenced
Distance Vector (MDSDV), is based on the well known single path Destination Sequenced
Distance Vector (DSDV). We show that the protocol finds node-disjoint
paths, i.e., paths which do not have any nodes in common, except for the source
and the destination.
The thesis presents a systematic evaluation of MDSDV in comparison with three
well known protocols: one proactive (DSDV), and two reactive (AODV) and (DSR).
MDSDV behaves very well in terms of its packet delivery fraction and data dropped in
both static and dynamic networks. It delivers nearly 100% of data in dense networks
(networks with more than 20 nodes). The speed of the nodes and the number of
sources have a low impact on its performance
A Survey of QoS Routing Protocols for Ad Hoc Networks
The aim of this paper is to give a big survey in enhancing the balance of the routing load and the consumption of resources using network layer metrics for the path discovery in the MAODV protocol. A ad hoc network (AD HOC NETWORKS) consists of a collection of wireless mobile nodes, which form a temporary network without relying on any existing infrastructure or centralized administration. The bandwidth of the ad hoc networks architecture is limited and shared between the participating nodes in the network, therefore an efficient utilization of the network bandwidth is very important. Multicasting technology can minimize the consumption of the link bandwidth and reduce the communication cost too. As multimedia and group-oriented computing gains more popularity for users of ad hoc networks, the effective Quality of Service (QoS) of the multicasting protocol plays a significant role in ad hoc networks. In this paper we propose a reconstruction of the MAODV protocol by extending some featuring QoS in MAODV. All simulations are prepared with the NS2 simulator and compare the performance of this algorithm with the MAODV algorithm. The achieved results illustrate faster path discovery and more performing routing balance in the use of MAODV-Extension.This paper would give relatively a modest support in Mobile Technology according to QoS communication
Peer-to-peer overlay in mobile ad-hoc networks
Wireless multi-hop networks such as mobile ad-hoc (MANET) or wireless mesh networks (WMN) have attracted big research efforts during the last years as they have huge potential in several areas such as military communications, fast infrastructure replacement during emergency operations, extension of hotspots or as an alternative communication system. Due to various reasons, such as characteristics of wireless links, multi-hop forwarding operation, and mobility of nodes, performance of traditional peer-to-peer applications is rather low in such networks. In this book chapter, we provide a comprehensive and in-depth survey on recent research on various approaches to provide peer-to-peer services in wireless multi-hop networks. The causes and problems for low performance of traditional approaches are discussed. Various representative alternative approaches to couple interactions between the peer-to-peer overlay and the network layer are examined and compared. Some open questions are discussed to stimulate further research in this area. © 2010 Springer Science+Business Media, LLC
7. GI/ITG KuVS Fachgespräch Drahtlose Sensornetze
In dem vorliegenden Tagungsband sind die Beiträge des Fachgesprächs Drahtlose Sensornetze 2008 zusammengefasst. Ziel dieses Fachgesprächs ist es, Wissenschaftlerinnen und Wissenschaftler aus diesem Gebiet die Möglichkeit zu einem informellen Austausch zu geben – wobei immer auch Teilnehmer aus der Industrieforschung willkommen sind, die auch in diesem Jahr wieder teilnehmen.Das Fachgespräch ist eine betont informelle Veranstaltung der GI/ITG-Fachgruppe „Kommunikation und Verteilte Systeme“ (www.kuvs.de). Es ist ausdrücklich keine weitere Konferenz mit ihrem großen Overhead und der Anforderung, fertige und möglichst „wasserdichte“ Ergebnisse zu präsentieren, sondern es dient auch ganz explizit dazu, mit Neueinsteigern auf der Suche nach ihrem Thema zu diskutieren und herauszufinden, wo die Herausforderungen an die zukünftige Forschung überhaupt liegen.Das Fachgespräch Drahtlose Sensornetze 2008 findet in Berlin statt, in den Räumen der Freien Universität Berlin, aber in Kooperation mit der ScatterWeb GmbH. Auch dies ein Novum, es zeigt, dass das Fachgespräch doch deutlich mehr als nur ein nettes Beisammensein unter einem Motto ist.Für die Organisation des Rahmens und der Abendveranstaltung gebührt Dank den beiden Mitgliedern im Organisationskomitee, Kirsten Terfloth und Georg Wittenburg, aber auch Stefanie Bahe, welche die redaktionelle Betreuung des Tagungsbands übernommen hat, vielen anderen Mitgliedern der AG Technische Informatik der FU Berlin und natürlich auch ihrem Leiter, Prof. Jochen Schiller
Review of multicast QoS routing protocols for mobile ad hoc networks
A Mobile Ad hoc NETwork (MANET) is consisting of a
collection of wireless mobile nodes, which form a temporary
network without relying on any existing infrastructure or
centralized administration. Since the bandwidth of MANETs is
limited and shared between the participating nodes in the
network, it is important to efficiently utilize the network
bandwidth. Multicasting can minimize the link bandwidth
consumption and reduce the communication cost by sending the
same data to multiple participants. Multicast service is critical for
applications that need collaboration of team of users.
Multicasting in MANETs becomes a hot research area due to the
increasing popularity of group communication applications such
as video conferencing and interactive television. Recently,
multimedia and group-oriented computing gains more popularity
for users of ad hoc networks. So, effective Quality of Service
(QoS) multicasting protocol plays significant role in MANETs.
In this paper, we are presenting an overview of set of the most
recent QoS multicast routing protocols that have been proposed
in order to provide the researchers with a clear view of what has
been done in this field
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