Search results for " Wireless"

Control Architecture for Wireless MAC Processor Networking

2013

Abstract: In these years, the proliferation of unplanned WLANs is creating the need of implementing different adaptation strategies for improving the network per- formance under mutating and evolving interference scenarios. Many vendors pro- pose undisclosed MAC/PHY optimization solutions, such as ambient noise immunity schemes, dynamic tuning of operating channels and contention parameters, etc., rely- ing on low-level implementations in the card hardware/firmware. In this paper we envision a new solution for expressing and implementing high-level adaptation policies in WLANs, in contrast to the current approaches based on vendor- specific implementations. We exploit the hardware abstracti…

Flexible and Modular Support for Multicast Rate Adaptation in WLANs

2013

The flexibility and virtualization capabilities provided by wireless cards have received significant attention as a means to reduce development costs. In this paper we present a modular architecture that exploits the features provided by emerging PHY and MAC implementations to rapidly develop new rate adaptation algorithms for multicast trans- mission in wireless LANs. We validate our solution by developing three rate adapta- tion algorithms that use an innovative sensing mechanism to evaluate the frame recep- tion correlation of the members of the multicast group. The experimental results obtained on a real-life testbed show that our solutions permit to increase the performance of multicas…

Fading mitigation coding techniques for space to ground free space optical communications

2014

Coloring-based resource allocations in ad-hoc wireless networks

2011

It is well known that CSMA/CA protocols exhibit very poor performance in case of multi-hop transmissions, because of inter-link interference due to imperfect carrier sensing. We propose to control such an interference by preallocating temporal slots in which different sets of network nodes are allowed to contend for the channel access. The approach is based on distributed coloring algorithms with limited signaling overhead that can be customized as a function of the network topology and traffic load.

An Ambient Intelligence Architecture for Extracting Knowledge from Distributed Sensors

2009

Precisely monitoring the environmental conditions is an essential requirement for AmI projects, but the wealth of data generated by the sensing equipment may easily overwhelm the modules devoted to higher-level reasoning, clogging them with irrelevant details. The present work proposes a new approach to knowledge extraction from raw data that addresses this issue at different levels of abstraction. Wireless sensor networks are used as the pervasive sensory tool, and their computational capabilities are exploited to remotely perform preliminary data processing. A central intelligent unit subsequently extracts higher-level concepts represented in a geometrical space and carries on symbolic re…

Exploiting the Human Factor in a WSN-Based System for Ambient Intelligence

2009

Practical applications of ambient intelligence cannot leave aside requirements about ubiquity, scalability, and transparency to the user. An enabling technology to comply with this goal is represented by wireless sensor networks (WSNs); however, although capable of limited in-network processing, they lack the computational power to act as a comprehensive intelligent system. By taking inspiration from the sensory processing model of complex biological organisms, we propose here a cognitive architecture able to perceive, decide upon, and control the environment of which the system is part. WSNs act as a transparent interface that allows the system to understand human requirements through impl…

Extracting Structured Knowledge From Sensor Data for Hybrid Simulation

2014

Obtaining continuous and detailed monitoring of indoor environments has today become viable, also thanks to the widespread availability of effective and flexible sensing technology; this paves the way for the design of practical Ambient Intelligence systems, and for their actual deployment in real-life contexts, which require advanced functionalities, such as for instance the automatic discovery of the activities carried on by users. Novel issues arise in this context; on one hand, it is important to reliably model the phenomena under observation even though, to this end, it is often necessary to craft a carefully designed prototype in order to test and fine-tune the theoretical models.

A Hybrid Framework for Soft Real-Time WSN Simulation

2009

The design of a wireless sensor network is a chal- lenging task due to its intrinsically application-specific nature. Although a typical choice for testing such kind of networks requires devising ad-hoc testbeds, this is often impractical as it depends on expensive, and hard to maintain deployment of nodes. On the other hand, simulation is a valuable option, as long as the actual functioning conditions are reliably modeled, and carefully replicated. The present work describes a framework for supporting the user in early design and testing of a wireless sensor network with an augmented version of TOSSIM, the de-facto standard for simulators, that allows merging actual and virtual nodes seaml…

DC4CD

2017

In this article, we present Distributed Computing for Constrained Devices (DC4CD), a novel software architecture that supports symbolic distributed computing on wireless sensor networks. DC4CD integrates the functionalities of a high-level symbolic interpreter, a compiler, and an operating system, and includes networking abstractions to exchange high-level symbolic code among peer devices. Contrarily to other architectures proposed in the literature, DC4CD allows for changes at runtime, even on deployed nodes of both application and system code. Experimental results show that DC4CD is more efficient in terms of memory usage than existing architectures, with which it also compares well in te…

Robust Data Gathering for Wireless Sensor Networks

2006

2005 13th IEEE International Conference on Networks jointly held with the 2005 7th IEEE Malaysia International Conference on Communications, Proceedings Volume 1, 2005, Article number 1635527, Pages 469-474 2005 13th IEEE International Conference on Networks jointly held with the 2005 7th IEEE Malaysia International Conference on Communications; Kuala Lumpur; Malaysia; 16 November 2005 through 18 November 2005; Category number05EX1235; Code 69262 Robust data gathering for wireless sensor networks (Conference Paper) Ortolani, M. , Gatani, L. , Lo Re, G. Dipartimento di Ingegneria Informatica, Università degli Studi di Palermo, Viale delle Scienze Parco d'Orleans, 90128 Palermo, Italy View re…