Samuela Persia

Measurements of the performance degradation of UMTS receivers due to UWB emissions

Results of experimental trials performed to assess the coexistence of the UMTS systems and the UWB emissions are presented. The performance degradation of the UMTS system vs. the in-channel UWB interference power has been measured in terms of the bit error rate and the noise rise.

RF propagation analysis for ZigBee Sensor Network using RSSI measurements

The scope of this work is to investigate the RF behavior of ZigBee devices operating within a real environment. On this purpose a Wireless Sensor Network (WSN) ZigBee based has been deployed in a specific indoor context. Three different RSSI measurement campaigns have been carried out to characterize the main propagation features. On the basis of the experimental results it has been possible to analyze the different factors that affect the measurements, such as external factors (e.g. multipath, fading) or internal ones (e.g. hardware device, integrated antennas). The first campaign, made nearby the transmitter, was performed to study the internal and external factor effects, the second one to extend the range of the first experiment, and the latter to investigate the propagation trying to isolate the external phenomena. Furthermore to deeply analyze the ZigBee behavior we have compared the measurements with a suitable propagation model. This work allows the definition of the main performance requirements for a ZigBee Sensor Network deployed in real building environment.

Performance Analysis of Underwater Swarm Sensor Networks

Fundamental key aspects of underwater acoustic communications have been taken into account to define an underwater swarm network for monitoring and exploration applications. We discuss the communication architecture of underwater sensor networks as well as the factors that influence underwater network design. Specifically, the main requirements needed to design a suitable sensors underwater system has been provided by considering a Cross-Layer solution among the lower layers of the node to maintain the power consumption as low as possible without complexity addition in the architecture design. Results show that the average power can be preserved thanks to power control implementation used to optimize the overall across the physical, Medium Access Control (MAC) and Network (NWK) layers. This study wants to provide the performance analysis of a swarm network model to provide guideline for hardware developing of swarm nodes for a real underwater application.

Wireless M2M capacity analysis for smart distribution grids

In the recent years, advanced control techniques for power grid distribution have been provided in order to define a new concept of power grid management: the Smart Grid. Among of them, the use of Machine-to-Machine (M2M) will permit to define advanced monitoring system for the distribution grid. However, the unique characteristics of M2M communications pose a number of interesting challenges to the conventional telecommunications networks. In this paper, we analyzed the 4G cellular technology, the Long Term Evolution (LTE), to investigate if it could be a suitable technology for the local loop solution. The analysis in terms of coverage and capacity is provided taking into account two exemplary case studies: AMI (Advanced Metering Infrastructure) and Distribution Substation Monitoring. The aim of this work is to check whether wireless access method of cellular technology is able to satisfy the proposed applications requirements.

IPv4Wireless multimedia sensor networks

The acquisition and distribution of multimedia content, such as still images, audio and video streams, are the new frontier of wireless sensor networks (WSNs). Scalar data WSNs commonly rely on the IEEE 802.15.4 standard that defines suitable physical and medium access control layers, whereas wireless multimedia sensor networks (WMSNs) need advanced architectures able to maintain a predetermined level of quality of service (QoS). In this paper, we analyze the potential of the combination of IPv4 and the IEEE 802.15.4 standard, if employed in the innovative VISIONs architecture for WMSNs, designed to support real-time video streaming. We implement IPv4 at the network (NWK) layer, because it is the most suitable protocol to guarantee the interoperability among heterogeneous networks, hence it easily allows the remote access to the WMSNs content. Suitable protocols for network management will provide the relevant performance parameters to the QoS engine of the VISIONs architecture that will enable the full adaptability of nodes to the context. Since the main QoS requirements for real time video streaming are the maximum tolerable end-to-end delay and packet loss, our performance evaluation focuses on the analysis of latency and transmitted frames, in the presence of different traffic sources. We also measure the power consumption of WMSNs nodes for the video streaming service.

Cross-Layer Design of a LDR-L/T UWB Sensor Network

Low data rate location/tracking UWB sensors have both location/tracking and communication capabilities, calling for novel routing and MAC strategies, in order to efficiently manage ranging and data transfer. In this paper, a particular configuration is adopted for routing and MAC, that are strongly correlated, because both are tied to the ranging module. Hence, a cross-layer design approach appears as the most appropriate. The routing algorithm, the e-GPSR, is a novel energy-aware version of a geographic reactive multi-hop protocol, namely the greedy perimeter stateless routing (GPSR). The MAC scheme is a modified hybrid slotted-aloha time-hopping code division multiple access. Performance of the e-GPSR are evaluated as a function of design parameters of MAC and ranging module. Optimal values are provided for different degrees of networks mobility such that MAC and ranging are optimally designed to provide best performance of routing.

Data Link Layer Effect over Swarm Underwater Network Performance

The Underwater Swarm is a particular Underwater Network configuration characterized by nodes very close one to each other, with mobility capability. This type of network raises challenges for its effective design and development, for which the only use of acoustic communication as traditionally suggested in underwater communication could be not enough. A new emerging solution could be a hybrid solution that combines the use of acoustic and optical channel in order to overcome the acoustic channel limitations in underwater environment. In this work we want to investigate how the acoustic and optical communications influence the Underwater Swarm performance by considering the Data Link Layer effects over the two different propagation technologies. Performance simulations have been carried out to suggest how a new Underwater Swarm based on hybrid communication technology could be designed.

Next generation M2M Cellular Networks: LTE-MTC and NB-IoT capacity analysis for Smart Grids applications

LTE technology, although traditionally defined for H2H (Human-to-Human) Communications, could be a good candidate for M2M (Machine-to-Machine) Communications. For this reason, the global 3GPP standard promotes in the recent Releases low complexity devices to support M2M applications. LTE-MTC (Machine-Type-Communications) and NB-IoT (Narrow Band Internet of Things) appear as promising solutions for Smart Grid services. In this work, specific use cases, such as emerging Energy Services, have been investigated by evaluating coverage and capacity analysis in real context, to investigate how new M2M devices could be employed. This work wants to focus on the feasibility of the existing public LTE networks to support large number of devices in order to provide useful suggestions for future M2M Cellular Networks definition.

Digital holography for security applications

A survey of Digital Holography (DH) and its employment in different application fields is provided. This paper reviews the main principles of the DH focusing on the optical techniques for security purposes. Recording and processing of three dimensional data, secured storage data, the use of Multimedia Sensor Network (MSN) for encrypted data transmission, and thus remote reconstruction of 3D images, are relevant examples in which DH represents an attractive solution. In this work, the state of art and major research challenges for this type of applications are shown and at the end fundamental open issue are discussed in order to outline the future research trends in this topic.

ZigBee Sensor Network propagation analysis for health-care application

The goal of the work is to investigate the Radio Frequency (RF) propagation of ZigBee devices operating within a hospital environment to analyze their real indoor behaviour to design healthcare systems. Different Received Signal Strength Inidcation (RSSI) measurement campaigns have been carried out to characterize the main propagation features. On the basis of the experimental results it has been possible to analyze the different factors that affect the measurements, such as external factors (e.g. multipath, fading) or internal ones (e.g. hardware device, integrated antennas). Furthermore to deeply define the ZigBee behavior we have compared the measurements with a suitable propagation model. This preliminary study permitted us to include the main measurements outcomes in a planning simulator which emulates the radio propagation in hospital environments. Specifically the planning model proposed is useful to design a “Smart Hospital” and thus to define main performance requirements for a ZigBee Sensor Network deployed in real hospital environment.