Relazioni tra Sistemi Informativi ed E-Governament della Sanità

In questo articolo vengono analizzati alcuni aspetti dell’e-governament della sanità, in particolare si descrivono le relazioni esistenti tra Sistemi Informativi Ospedalieri, ed il management aziendale, i servizi amministrativi, il personale medico e l’utenza. La recente tendenza ad intensificare le cure del paziente al fine di diminuire il tempo di degenza e quindi di contenere la spesa sanitaria ha reso necessario l’ adeguamento delle strutture sanitarie alle nuove tecnologie. L’ospedale moderno sin dalla fase progettuale deve essere concepito razionalmente come un contenitore di tecnologie con il massimo d’integrazione tra le stesse: in questa struttura le informazioni cliniche amministrative e di management assumono sempre più importanza e diventa fondamentale il loro scambio in modo efficiente. Queste informazioni sono gestite dal Sistema Informativo Ospedaliero (SIO): si tratta di un sistema finalizzato alla raccolta, all’analisi ed al recupero di tutti i dati connessi alla gestione del paziente, ai servizi diagnostici ed amministrativi, alle tecnologie biomediche ed informatiche. All’interno del SIO i flussi di informazione sono tali da offrire un accesso completo ai dati clinici per disporre di una cartella clinica elettronica funzionale allo sviluppo delle terapie e dei protocolli diagnostici. Una particolare attenzione è stata rivolta agli aspetti legati alla sicurezza ed alla riservatezza dei dati sensibili ed all’impatto dell’informatizzazione nel sistema sanitario considerandone la criticità dell’introduzione di nuove procedure informatizzate sull’organizzazione preesistente dei reparti e dell’intero ospedal

Providing Enhanced Framework to support QoS in Open Wireless Architecture

This paper presents a novel approach to support Quality of Service for Open Wireless Architectures (OWA), building a suitable framework over the top of the heterogeneous wireless MACs. It lets to enhance the existing QoS support provided by standard MAC protocols and it uses the contract model to guarantee QoS, taking into account the applications requests. It negotiates dynamically Application Level Contracts which will be translated seamlessly in Resource Level Contracts for the underlying network services. It receives the feedback by underlying network services to adjust the scheduling algorithms and policies to provide hard and soft guarantees. The framework comprises QoS Manager, Admission Control, Enhanced Scheduler, Predictor and Feedback System. The QoS manager component is able to dynamically manage available resources under different load conditions. A IEEE 802.11e Wireless LAN is simulated to show the benefits of this approach

Performance evaluation of real-time schedulers for HCCA function in IEEE 802.11e wireless networks

IEEE 802.11 standard for wireless networks recently has been enhanced with IEEE 802.11e amendment to this protocol which introduces Quality of Service support. It provides differentiation mechanisms at the Medium Access Control layer, using two additional access functions: the Enhanced Distributed Channel Access (EDCA) function and the HCF Controlled Channel Access (HCCA) function. The EDCA function is based on a distributed control and enables prioritized channel access while the latter requires centralized scheduling and allows the applications to negotiate parameterized service guarantees. Only HCCA mechanism is suitable for serving traffic streams with real-time requirements such as multimedia applications and Voice Over IP. The IEEE 802.11e standard does not specify a mandatory HCCA scheduling algorithm, while it offers a reference scheduler. In this paper we analyze four HCCA schedulers which are alternative to the reference one and which offer real-time guarantees. A performance evaluation through simulation is conducted to show the main differences between the considered schedulers, including the reference one

Toward the QoS Support in 4G Wireless Systems

This paper presents a novel approach to support Quality of Service for wireless multimedia applications in the context of 4G wireless systems. Adopting a Service Oriented Architecture, it is inspired to Open Wireless Architectures (OWA), building a suitable framework over the top of the heterogeneous wireless MACs. It lets to enhance the existing QoS support provided by standard MAC protocols and it uses the contract model to guarantee QoS, taking into account the applications requests. It negotiates dynamically Application Level Contracts which will be translated seamlessly in Resource Level Contracts for the underlying network services. It receives the feedback by underlying network services to adjust the scheduling algorithms and policies to provide soft guarantees. The framework comprises QoS Manager, Admission Control, Enhanced Scheduler, Predictor and Feedback System. In particular, the QoS manager component is a middleware between applications and lower network layers and it is able to dynamically manage available resources under different load conditions in a transparent manner to application level

Improving the design of wireless sensor networks using QoS-aware opportunistic techniques

The design of a Wireless Sensor Network with QoS is a challenging and complex topic especially when the post-deployment corrections are expensive. This paper proposes a design methodology of Wireless Sensor Networks to estimate network performance in terms of end-to-end delay and reliability. It uses a probabilistic model to determine the needed node density, then adopting a variant of geographic routing it lets to calculate the number of path hops. The introduced opportunistic mechanism offers a trade-off between low end-to-end delay and reliable packets delivery. The modeled network with the adopted Geographic Opportunistic Routing has been evaluated through simulations and some guidelines about its design in order to obtain desired performance are given

QoS Framework for wireless networks

This paper presents a work in progress about a cross-layer approach to support Quality of Service for wireless multimedia applications, building a suitable framework over the top of the heterogeneous wireless MACs. It lets to enhance the existing QoS support provided by standard MAC protocols and it uses the contract model to guarantee QoS, taking into account the applications requests. It negotiates dynamically Application Level Contracts which will be translated seamlessly in Resource Level Contracts for the underlying network services from which it receives the feedback to adjust the scheduling algorithms and policies to provide soft guarantees. The framework comprises QoS Manager, Admission Control, Enhanced Scheduler and Feedback System. The QoS manager component is a middleware able to dynamically manage available resources under different load conditions in a transparent manner to application level

A Scheduling Algorithm for Providing QoS Guarantees in 802.11e WLANs

In this paper we propose a scheduling algorithm for supporting Quality of Service (QoS) in an IEEE 802.11e network using the HCF Controlled Channel Access (HCCA) function. This is derived from Constant Bandwidth Server with Resource Constraints and adapted to wireless medium. It consists of a procedure to actually schedule transmission opportunities to HCCA flows with Quality of Service guarantees, in particular in the case of multimedia applications which present variable bit rate traffic

A IEEE 802.11e HCCA Scheduler with a Reclaiming Mechanism for Multimedia Applications

The QoS offered by the IEEE 802.11e reference scheduler is satisfactory in the case of Constant Bit Rate traffic streams, but not yet in the case of Variable Bit Rate traffic streams, whose variations stress its scheduling behavior. Despite the numerous proposed alternative schedulers with QoS, multimedia applications are looking for refined methods suitable to ensure service differentiation and dynamic update of protocol parameters. In this paper a scheduling algorithm,Unused Time Shifting Scheduler(UTSS), is deeply analyzed. It is designed to cooperate with a HCCA centralized real-time scheduler through the integration of a bandwidth reclaiming scheme, suitable to recover nonexhausted transmission time and assign that to the next polled stations. UTSS dynamically computes with anO(1)complexity transmission time providing an instantaneous resource overprovisioning. The theoretical analysis and the simulation results highlight that this injection of resources does not affect the admission control nor the centralized scheduler but is suitable to improve the performance of the centralized scheduler in terms of mean access delay, transmission queues length, bursts of traffic management, and packets drop rate. These positive effects are more relevant for highly variable bit rate traffic

Adopting Redundancy Techniques for Multicast Stream Authentication

Various schemes have been proposed to achieve strong authentication of streamed data in a lossy network by means of "light" digital signatures. Such techniques perform a strong authentication on only one packet, to which others are linked by means of hash functions, so that the authentication property propagates to them too. Most of these schemes make the basic assumption that the signature packet is not lost, even if no practical and precise solutions are proposed that guarantee such a property. In this paper we show how adoption of some redundancy techniques can be used in the context of multicast stream authentication in order to increase probability that the signature packets are received and correctly verified against their digital signature. Finally some experimental results are presented comparing computational overheads due to the authentication schemes both at the sender and at the receiver

W-CBS: A Scheduling Algorithm for Supporting QoS in IEEE 802.11e

This paper presents a new scheduling algorithm, the Wireless Constant Bandwidth Server (W-CBS) for the Access Points of an IEEE 802.11e wireless networks to support traffic streams with Quality of Service guarantees, in particular in the case of multimedia applications which present variable bit rate traffic. The performance of W-CBS is compared to that of the reference scheduler defined in 802.11e standard using the ns2 simulator. The results show that the W-CBS outperforms the reference scheduler with VBR traffic, in terms of resource utilization and maximum admitted flows