Search results for "Protocol"
showing 10 items of 1808 documents
Testbed implementation of the meta-MAC protocol
2016
The meta-MAC protocol is a systematic and automatic method to dynamically combine any set of existing MAC protocols into a single higher layer MAC protocol. We present a proof-of-concept implementation of the meta-MAC protocol by utilizing a programmable wireless MAC processor (WMP) on top of a commodity wireless card in combination with a host-level software module. The implementation allows us to combine, with certain constraints, a number of protocols each represented as an extended finite state machine. To illustrate the combination principle, we combine protocols of the same type but with varying parameters in a wireless mesh network. Specifically, we combine TDMA protocols with all po…
A Wireless Mesh Network-based System for Hotspots Deployment and Management
2007
In recent years Wireless Local Area Networks (WLANs) or hotspots, as they are commonly known, have emerged as a promising networking platform to extend network connectivity in public venues, providing local coverage for Internet applications on the move in urban areas and rural environments. Wireless hotspots using 802.11-based technology have popped up in corporate offices, coffeehouses, airports, restaurants and bookstores worldwide. For all their utility and ease of use the 802.11 wireless protocol, known as WiFi, has become the mobile connectivity mechanism of choice for business people, travelers, villagers, and everyone else. Unfortunately, even with the protocol's ease of use and its…
Making WiFi work in multi-hop topologies: Automatic negotiation and allocation of airtime
2015
We propose a solution for mitigating the performance impairments of CSMA/CA protocols in multi-hop topologies based on the dynamic adaptation of the contention process experienced by nodes in a wireless network. A distributed protocol is used to negotiate the channel airtime for a node as a function of the traffic requirements of its neighbourhood, taking into account bandwidth reserved for the control operations. A mechanism is provided for a node to tune its contention window depending on its allocated airtime. Different from previous schemes, a node's contention window is fixed in size unless the traffic requirements of its neighbourhood change. The scheme is implemented on legacy commer…
COVID-19 Pandemic: Prevention and protection measures to be adopted at the workplace
2020
Introduction: SARS-CoV-2, identified in Wuhan, China, for the first time in December 2019, is a new viral strain, which has not been previously identified in humans; it can be transmitted both by air and via direct and indirect contact; however, the most frequent way it spreads is via droplets. Like the other viruses belonging to the same family of coronaviruses, it can cause from mild flu-like symptoms, such as cold, sore throat, cough and fever, to more severe ones such as pneumonia and breathing difficulties, and it can even lead to death. Since no effective specific drug therapy has been found yet, nor any vaccine capable of limiting the spread of this pathogen, it is important for way…
Meeting others—supporting situation awareness on the WWW
2001
Abstract World Wide Web (WWW) techniques provide a simple interface, which is accessible almost everywhere. The WWW supports document sharing and information retrieval, but has no tools for direct user interaction, simply because the mechanisms to support user awareness are missing. The aim of this paper is twofold. First, we present general concepts of situation awareness, which concerns the user interaction on the WWW platform, and a theoretical framework, which is used in examining existing awareness support systems. Second, we provide an analysis of PeopleAwarenessEngine, which supports situation awareness and enables user communication and collaboration on the WWW.
Interoperability between Distributed Systems and Web-Services Composition
2009
An information system is a multi-axis system characterized by a “data” axis, a “behavioral” axis, and a “communication” axis. The data axis corresponds to the structural and schematic technologies used to store data into the system. The behavioral axis represents management and production processes carried out by the system and corresponding technologies. The processes can interact with the data to extract, generate, and store data. The communication axis relates to the network used to exchange data and activate processes between geographically distant users or machines. Nowadays, technologies required for interoperability are extended to deal with the semantic aspect of the information sys…
Content Production Strategies for E-Government
2008
The terms electronic government (e-government) and digital government are used to refer to the utilization of the Internet and other information and communication technologies (ICT) effectively in public sectors. In e-government development activities, the concern is often in building new means to support and strengthen democracy (e.g., Watson, Alselsen, Evjemo, & Aarsæther, 1999). In other cases, the main concern may be in supporting the work of people in public sectors (e.g., Mustajärvi, 2003), or in building new kinds of services for citizens (e.g., Lyytikäinen, Tiitinen, & Salminen, 2000). Common to most development activities is the need to have the content of public sector inf…
A novel policy-driven reversible anonymisation scheme for XML-based services
2015
Author's version of an article in the journal: Information Systems. Also available from the publisher at: http://dx.doi.org/10.1016/j.is.2014.05.007 This paper proposes a reversible anonymisation scheme for XML messages that supports fine-grained enforcement of XACML-based privacy policies. Reversible anonymisation means that information in XML messages is anonymised, however the information required to reverse the anonymisation is cryptographically protected in the messages. The policy can control access down to octet ranges of individual elements or attributes in XML messages. The reversible anonymisation protocol effectively implements a multi-level privacy and security based approach, s…
Polymorphisms in DNA repair genes modulate survival in cisplatin/gemcitabine-treated non-small-cell lung cancer patients.
2006
Abstract Background: Impaired DNA repair capacity may favorably affect survival in cisplatin/gemcitabine-treated non-small-cell lung cancer (NSCLC) patients. We investigated the association of survival with genetic polymorphisms in X-ray repair cross-complementing group 1 and group 3 (XRCC3), xeroderma pigmentosum group D (XPD), excision repair cross-complementing group 1, ligase IV, ribonucleotide reductase, TP53, cyclooxygenase-2, interleukin-6, peroxisome proliferator-activated receptor γ, epidermal growth factor, methylene-tetra-hydrofolate reductase and methionine synthase. Patients and methods: One hundred and thirty-five stage IV or IIIB (with malignant pleural effusion) NSCLC patien…
Fast Secure Routing for Highly Mobile Large-Scale Ad-Hoc Vehicular Networks
2009
In highly mobile large-scale vehicular ad-hoc networks, routing protocols must be fast and efficient in terms of low routing discovery delay and communication overhead to support the applications such as car talk. Such requirement becomes more difficult to achieve when inducing security enhancement to tackle the authentication of routing messages. In this paper, we propose a lightweight (fast) secure routing protocol, Secure Proactive Tree-based Routing (SPTR) to hit these two points. SPTR makes use of the characteristics of VANET networks, that is, the traffic originates from or terminates at the gateway or road side unit. SPRT also takes advantages of certificate-less ID-based cryptograph…