1,720,992 research outputs found
Inducing collisions for fast RFID tag identification
No full textEfficient tag reading is one of the major challenges in RFID systems. So far, most of the literature has assumed that interference is intrinsically harmful and must be avoided. For this reason prior work aims at singulating tag transmissions in order to prevent collisions. In this paper we adopt the opposite approach: rather than working against interference, we embrace the collision of radio waves. We propose a new protocol, called TIANC, which uses multiple antennas and analog network coding (ANC) to recover the original tag transmissions. Performance analysis shows that TIANC achieves substantial speed improvement, performing up to 2.3 times faster than previously proposed mechanism
SECY APP: self configuration and easy management for software defined smart homes
Full text linkIn this paper we address configuration and management issues of smart homes. Current platforms requires the user to deal with several management inconvenience problems, such as increasing devices, operating between devices, and using new devices. From a user perspective, system configuration and management are major issues: ordinary consumers want to use systems performing minimal configuration. To address this issue, we propose a platform, composed of a web application and Software Defined Network (SDN). While the user interacts with an easy-to-use interface on a smart device, the app automatically generates and installs SDN rules. Our platform, besides facilitating configuration and management, results more efficient --- up to 4 times faster --- and reliable --- able to operate even in case of no connection with the cloud --- than current solutions
A flexible Cross-Layer Interface for Ad-Hoc Networks: Architectural Design and Implementation Issues
No full text
Adaptive communication for battery-free devices in smart homes
Full text linkWith the ever-growing usage of batteries in the IoT era, the need for more eco-friendly technologies is clear. RF-powered computing enables the re-design of personal computing devices in a battery-less manner. While there has been substantial work on the underlying methods for RF-powered computing, practical applications of this technology has largely been limited to scenarios that involve simple tasks. This article demonstrates how RFID technology, typically used to implement object identification and counting, can be exploited to realize a battery-free Smart Home. In particular, we consider the coexistence of several battery-free devices, with different transmission requirements — periodic, event based, and real-time — and propose a new adaptive and quick-to-learn MAC protocol, called APT-MAC, which dynamically collects information from devices without requiring any a priori knowledge of the environment. Extensive simulations clearly show the benefits of using APT-MAC, which is able to successfully deliver 97.7% of new data samples in complex scenarios, including several high traffic demanding devices such as joysticks and cameras
Reliable and efficient forwarding in ad hoc networks
No full textThis paper focuses on packet forwarding in ad hoc networks and proposes a new approach to improve performance of nodes communication. In particular, we present a lightweight mechanism for REliable and Efficient Forwarding (REEF), which mitigates the effects of adverse situations caused by cooperation misbehavior or network fault conditions. It exploits nodes' local knowledge to estimates route reliability, and multi-path routing to forward packets on the most reliable route. REEF becomes also a security mechanism in case of a security association established between the communication parties. This additional feature makes the mechanism robust, guaranteeing trustworthiness of the reliability estimator and security of data transmission. A new approach to cooperation enforcing is also proposed. The classical method denies service to misbehaving nodes by, for example, not serving their forwarding requests. We approach the problem less drastically, differentiating the quality of service provided to nodes according to their behavior. In other words, traffic of misbehaving nodes will flow through the network slower than that one of reliable nodes. © 2004 Elsevier B.V. All rights reserved
Reti di calcolatori. Un approccio Top-Down
No full textLibro di testo per corso di Reti di Elaboratori per laurea in Informatica e Ingegneria Informatic
Environment-driven Communication in Battery-free Smart Buildings
No full textRecent years have witnessed the design and development of several smart devices that are wireless and battery-less. These devices exploit RFID backscattering-based computation and transmissions. Although singular devices can operate efficiently, their coexistence needs to be controlled, as they have widely varying communication requirements, depending on their interaction with the environment. The design of efficient communication protocols able to dynamically adapt to current device operation is quite a new problem that the existing work cannot solve well. In this article, we propose a new communication protocol, called ReLEDF, that dynamically discovers devices in smart buildings and their active and nonactive status and when active their current communication behavior (through a learning-based mechanism) and schedules transmission slots (through an Earliest Deadline First-- (EDF) based mechanism) adapt to different data transmission requirements. Combining learning and scheduling introduces a tag starvation problem, so we also propose a new mode-change scheduling approach. Extensive simulations clearly show the benefits of using ReLEDF, which successfully delivers over 95% of new data samples in a typical smart home scenario with up to 150 heterogeneous smart devices, outperforming related solutions. Real experiments are also conducted to demonstrate the applicability of ReLEDF and to validate the simulations
Battery-free smart objects based on RFID backscattering
No full textThe Internet of Things era has witnessed an explosion of smart objects. As we move toward connecting the next billion wireless devices to the Internet, however, the use of batteries to power them will become unworkable, with significant repercussions on health and the environment if improperly disposed. Hence, the need for more eco-friendly technologies. This article shows how radio-frequency identification technology enables the re-design of personal wireless computing devices in a battery-less manner, representing a major leap forward in moving beyond chargers, cords, and dying devices. Specifically, we study the development of various battery-free devices, and identify the types of devices that can be handled today and what is future work. We describe testbed experiments that clearly demonstrate the feasibility of the devices we built, presenting performance comparable to commercial battery-powered counterparts
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