Search results for "access"

An energy analysis of IEEE 802.15.6 scheduled access modes

2010

Body Area Networks (BANs) are an emerging area of wireless personal communications. The IEEE 802.15.6 working group aims to develop a communications standard optimised for low power devices operating on, in or around the human body. IEEE 802.15.6 specifically targets low power medical application areas. The IEEE 802.15.6 draft defines two main channel access modes; contention based and contention free. This paper examines the energy lifetime performance of contention free access and in particular of periodic scheduled allocations. This paper presents an overview of the IEEE 802.15.6 and an analytical model for estimating the device lifetime. The analysis determines the maximum device lifeti…

Coexistence between IEEE802.15.4 and IEEE802.11 through cross-technology signaling

2017

When different technologies use the same frequency bands in close proximity, the resulting interference typically results in performance degradation. Coexistence methods exist, but these are often technology specific and requiring technology specific interference detection methods. To remove the root cause of the performance degradation, devices should be able to negotiate medium access even when using different technologies. To this end, this paper proposes an architecture that allows crosstechnology medium access by means of a Time Division Multiple Access (TDMA) scheme. In order to achieve cross-technology synchronization, which is required for the TDMA solution, an energy pattern beacon…

Random access with repeated contentions for emerging wireless technologies

2017

In this paper we propose ReCo, a robust contention scheme for emerging wireless technologies, whose efficiency is not sensitive to the number of contending stations and to the settings of the contention parameters (such as the contention windows and retry limits). The idea is iterating a basic contention mechanism, devised to select a sub-set of stations among the contending ones, in consecutive elimination rounds, before performing a transmission attempt. Elimination rounds can be performed in the time or frequency domain, with different overheads, according to the physical capabilities of the nodes. Closed analytical formulas are given to dimension the number of contention rounds in order…

Achieving Robustness through Caching and Retransmissions in IEEE 802.15.4-based WSNs

2007

This paper proposes a network-layer protocol for wireless sensor networks based on the IEEE 802.15.4 standard. Our protocol is devised to provide reliable data gathering in latency-constrained applications, and exploits both the flexibility of the IEEE 802.15.4 MAC layer and features of data aggregation techniques, such as implicit acknowledgment of reception. The proposed protocol acts as a routing module and a control entity for the MAC layer and provides reliable communication, while managing power saving and synchronizertion among nodes. Without relying on MAC-layer acknowledgments, the protocol implements caching and network-layer retransmissions, triggered upon detection of a link fai…

An extended JADE-S based framework for developing secure Multi-Agent Systems

2009

Agent communities are self-organized virtual spaces consisting of a large number of agents and their dynamic environments. Within a community, agents group together offering special e-services for effective, reliable, and mutual benefits. Usually, an agent community is composed of specialized agents performing one or more tasks in a single domain/sub-domain, or in highly intersecting domains. However, secure Multi- Agent Systems require severe mechanisms in order to prevent malicious attacks. Several limits affect exiting secure agents platform, such as the lack of a strong authentication system, the lack of a flexible distributed mechanism for access control and the lack of a system for st…

MEDIATION IN ITALY: NEW DISCIPLINE, OLD-STYLE LOGIC

2014

L'accesso al credito immobiliare

2018

The essay deals with the issue of the various forms of financing real estate purchases with particular regard to the new types of contracts designed specifically to facilitate access to credit, such as rent to buy, the real estate lifetime loan, the real estate credit to businesses and the real estate credit to consumers

sub artt. 38 e 39 d.lgs. n. 150/2009

2011

IL DIRITTO ALL'ISTRUZIONE AL COSPETTO DELLE CORTI DI STRASBURGO E DI LUSSEMBURGO: L'ACCESSO ALL'UNIVERSITÀ E LA QUESTIONE DEL NUMERO CHIUSO.

Quote rosa e parità tra i sessi: la storia di un lungo cammino

2019

Article 3.1 of the Italian Constitution enshrines the principle of equality and the prohibition of discrimination, based on “gender, race, language, religion, political opinion, personal and social conditions”. Additionally, Article 48 grants an equal right to men and women to vote, and Articles 56.3 and Article 58.1 establish the right to be elected to the Camera dei Deputati and the Senato della Repubblica without any reference to the gender of the candidates. Men and women voted in Italy the first time in an institutional referendum on 2 June 1946 to choose between a Republic and a Monarchy. However , the right for women to be elected came many years later, after a long and hard-fought s…