Nowadays, smart urban environments face increasing demands by citizens for reliable wireless connectivity to support the adoption of smart services, such as intelligent transportation systems. In this context, the city of Caltanissetta has implemented a comprehensive project focused on providing research and development services to facilitate the integration of such systems. The initiative includes the assessment and validation of LoRaWAN coverage models through empirical field testing, combining advanced simulation methodologies with real-world measurements to enhance the accuracy of propagation models in urban settings. Within this framework, SmartMe has deployed a software ecosystem based on its Stack4Things framework, alongside a LoRaWAN infrastructure, to monitor critical urban parameters such as weather conditions, air quality, park availability, and traffic flows, contributing to the development of smart mobility solutions. The urban deployment consists of a network of Cyber-Physical Systems (CPS) distributed throughout the city, with multiple edge elements contributing to real-time data collection. The validation process involves comparing simulated coverage predictions with field measurements, refining model parameters to optimize network performance and reliability.

Abstract Very popular mobile devices such as cellular phones, laptops, and handheld and tablet PCs are becoming more and more powerful. One of today's trends is to access multimedia services from this sort of device. Their low capacity in terms of storage, and their high inclination to wireless connection, suggest the use of streaming techniques instead of media download. Mobile devices are, at present, dramatically unhomogeneous for visualization and audio reproduction characteristics. Consequently, today multimedia delivery systems are very customized for some device profiles or for wireless connection types. Transcoding techniques are used in order to adapt the same media source to the multiple hardware profiles. Client‐based transcoding techniques show their weakness in high energy consumption, and server‐based transcoding techniques suffer from scalability problems. In this paper we propose a scalable distributed multimedia server based on the Grid computing paradigm, which can adapt media content to the device profile and/or to the connection link. Copyright © 2005 John Wiley & Sons, Ltd.

This paper proposes a methodological approach for the performance analysis of Web-based searching applications on the Internet. It specifically investigates the behavior of the client/server (C/S), remote-evaluation (REV) and mobile-agent (MA) communication paradigms and describes how Petri-net models can be developed to derive performance indices which can help the designer to improve the efficiency of his distributed applications. Our purpose is that of identifying a set of models that can help to understand the environmental situations in which such paradigms should be preferred or combined in order to optimize the performances of a distributed system. In particular, we propose a modeling technique applied to an information retrieval application on the World Wide Web. An analytical evaluation through the solution of nonMarkovian Petri-net models is provided, which allows us to identify the main parameters, as well as the way they interact, to be taken into consideration when distributed applications are to be designed. An experimental environment is also studied in order to obtain real measurements used to validate the analytical models.

This paper wishes to investigate the converging field of mobile and Grid computing by defining an architecture for the provision of Grid services, which Is based on standards, robust and useful across application domains. We propose using the mobile agent paradigm in order to develop a middleware layer that takes care of all the details to allow mobile users to access distributed resources in a transparent, secure and effective way. Our purpose Is also that of Identifying the environmental situations In which such paradigm should be preferred or adopted in conjunction with more traditional communication paradigms (i.e. client/server, Remote Evaluation). For this purpose, we provide an experimental and analytical evaluation of the Client-Server, Remote Evaluation and Mobile Agent communication paradigms.

Wireless devices are becoming very popular and powerful to be commonly adapted to access distributed services. More and more sophisticated applications are being developed and a very promising market is quickly being established where mobile users might access multimedia data while roaming from a cell to another, anytime and everywhere. Such scenario requires a strong infrastructure in order to adequately manage all the different issues related with high-level service provisioning. QoS represents one of the most crucial issues as it involves many different aspects and directly impacts the user satisfaction. In order to achieve this target, we propose an architecture, which allows mobile devices to access advanced services available in the wired part of the network. This architecture, based on mobile agents technology, assumes the presence of a VOD virtual server. The strategy adopted is to hide all the basic mechanisms inside a middleware layer that provides necessary interfaces to allow a simple interaction between the user on the one side and the network and the distributed services on the other. The overall architecture, that is currently being implemented and tested, has been used as an experimental environment to provide mobile users with a new service to access MPEG-4 flows.

This paper provides an experimental and analytical evaluation of the client-server, remote evaluation and mobile agent communication paradigms. Our purpose is that of identifying the environmental situations in which such paradigms should be preferred or combined in order to optimize the performances of a distributed system. The scenario selected for the analysis is information retrieval on the WWW. An analytical evaluation throughout the solution of non-Markovian Petri net models is provided.

Wireless communication systems are becoming the new enabling technology for accessing, sharing and processing data. It is easy to foresee that in the near future users will access the Internet through wireless PDA, while roaming from one place to another. Mobile ad-hoc networks (MANET) are peer-to-peer wireless networks that do not rely on the presence of a wired interconnection infrastructure. Apart from more traditional applications in the military field as well as in disaster recovery and emergency situations, MANET may represent an interesting possibility for personal communications and interaction among mobile users. We identify some possible fields of application for such wireless systems, identifying advantages and drawbacks. We also present a prototype application where MANETs are used in order to provide a distributed image processing service.