46,701 research outputs found
The Development of a Mobile Ad-Hoc Network Testbed: Modular Implementation of Ad-Hoc On-Demand Distance Vector Routing
In communication systems, a Mobile Ad-Hoc Network (MANET) is a communication topology that has no central infrastructure, in contrast to more common network topologies such as Wi-fi or cellular towers. MANETs are of particular interest in the field as Internet-of-Things (IOT) applications and the push towards 6th-generation (6G) communications continues. MANET networks provide communication access to all nodes within the network using peer-to-peer communications, requiring extensive maintenance and updating of routes within the network as nodes move around. Routing protocols must be designed and used for these networks, and are typically complex algorithms that are difficult to implement on hardware. To combat this, this work presents a MANET testbed, designed to provide users with an Application Programming Interface (API) that separates routing protocol implementation from operating system functionality. To verify the testbed, this work also presents an implementation of Ad-Hoc On-Demand Distance Vector Routing (AODV) that uses the provided API functions. By comparing simulation results from Network Simulator 3 (NS3), a physical implementation, and a physical implementation that uses firewall capabilities to form the network, a full evaluation of AODV and the MANET testbed is performed
Flat Cellular (UMTS) Networks
Traditionally, cellular systems have been built in a hierarchical manner: many specialized cellular access network elements that collectively form a hierarchical cellular system. When 2G and later 3G systems were designed there was a good reason to make system hierarchical: from a cost-perspective it was better to concentrate traffic and to share the cost of processing equipment over a large set of users while keeping the base stations relatively cheap. However, we believe the economic reasons for designing cellular systems in a hierarchical manner have disappeared: in fact, hierarchical architectures hinder future efficient deployments. In this paper, we argue for completely flat cellular wireless systems, which need just one type of specialized network element to provide radio access network (RAN) functionality, supplemented by standard IP-based network elements to form a cellular network. While the reason for building a cellular system in a hierarchical fashion has disappeared, there are other good reasons to make the system architecture flat: (1) as wireless transmission techniques evolve into hybrid ARQ systems, there is less need for a hierarchical cellular system to support spatial diversity; (2) we foresee that future cellular networks are part of the Internet, while hierarchical systems typically use interfaces between network elements that are specific to cellular standards or proprietary. At best such systems use IP as a transport medium, not as a core component; (3) a flat cellular system can be self scaling while a hierarchical system has inherent scaling issues; (4) moving all access technologies to the edge of the network enables ease of converging access technologies into a common packet core; and (5) using an IP common core makes the cellular network part of the Internet
A Mediation Framework for Mobile Web Service Provisioning
Web Services and mobile data services are the newest trends in information
systems engineering in wired and wireless domains, respectively. Web Services
have a broad range of service distributions while mobile phones have large and
expanding user base. To address the confluence of Web Services and pervasive
mobile devices and communication environments, a basic mobile Web Service
provider was developed for smart phones. The performance of this Mobile Host
was also analyzed in detail. Further analysis of the Mobile Host to provide
proper QoS and to check Mobile Host's feasibility in the P2P networks,
identified the necessity of a mediation framework. The paper describes the
research conducted with the Mobile Host, identifies the tasks of the mediation
framework and then discusses the feasible realization details of such a mobile
Web Services mediation framework.Comment: Proceedings of 2006 Middleware for Web Services (MWS 2006) Workshop @
10th International IEEE EDOC Conference "The Enterprise Computing
Conference", October 16, 2006, pp. 14-17. IEEE Computer Societ
Wireless communication, identification and sensing technologies enabling integrated logistics: a study in the harbor environment
In the last decade, integrated logistics has become an important challenge in
the development of wireless communication, identification and sensing
technology, due to the growing complexity of logistics processes and the
increasing demand for adapting systems to new requirements. The advancement of
wireless technology provides a wide range of options for the maritime container
terminals. Electronic devices employed in container terminals reduce the manual
effort, facilitating timely information flow and enhancing control and quality
of service and decision made. In this paper, we examine the technology that can
be used to support integration in harbor's logistics. In the literature, most
systems have been developed to address specific needs of particular harbors,
but a systematic study is missing. The purpose is to provide an overview to the
reader about which technology of integrated logistics can be implemented and
what remains to be addressed in the future
Mobile Computing in Digital Ecosystems: Design Issues and Challenges
In this paper we argue that the set of wireless, mobile devices (e.g.,
portable telephones, tablet PCs, GPS navigators, media players) commonly used
by human users enables the construction of what we term a digital ecosystem,
i.e., an ecosystem constructed out of so-called digital organisms (see below),
that can foster the development of novel distributed services. In this context,
a human user equipped with his/her own mobile devices, can be though of as a
digital organism (DO), a subsystem characterized by a set of peculiar features
and resources it can offer to the rest of the ecosystem for use from its peer
DOs. The internal organization of the DO must address issues of management of
its own resources, including power consumption. Inside the DO and among DOs,
peer-to-peer interaction mechanisms can be conveniently deployed to favor
resource sharing and data dissemination. Throughout this paper, we show that
most of the solutions and technologies needed to construct a digital ecosystem
are already available. What is still missing is a framework (i.e., mechanisms,
protocols, services) that can support effectively the integration and
cooperation of these technologies. In addition, in the following we show that
that framework can be implemented as a middleware subsystem that enables novel
and ubiquitous forms of computation and communication. Finally, in order to
illustrate the effectiveness of our approach, we introduce some experimental
results we have obtained from preliminary implementations of (parts of) that
subsystem.Comment: Proceedings of the 7th International wireless Communications and
Mobile Computing conference (IWCMC-2011), Emergency Management: Communication
and Computing Platforms Worksho
- …