Showing papers by "Igor Bisio published in 2015"

Contact graph routing in DTN space networks: overview, enhancements and performance

Abstract: Delay- and Disruption Tolerant Networks (DTNs) are based on an overlay protocol and on the store-carry-forward paradigm. In practice, each DTN node can store information for a long time before forwarding it. DTNs are particularly suited to cope with the challenges imposed by the space environment. This paper is focused on routing in space DTNs, and in particular on contact graph routing (CGR) and its most representative enhancements, available in the literature, which are briefly surveyed in this work. Moreover, the applicability and the obtained performance of the DTN protocol stack and of the CGR have been evaluated by presenting results from real experimental experiences such as the Deep Impact Network experiment (employing the EPOXI space cruise), the JAXA jointly performed space link demonstrations with NASA (where the JAXA’s GEO relay satellite called Data Relay Test Satellite has been used), the Space Data Routers European Project, and the pilot operation of a DTN implementation on the International Space Station (ISS).

Smartphone-centric ambient assisted living platform for patients suffering from co-morbidities monitoring

Abstract: Recently, patients suffering from a set of physical and mental limitations, called co-morbidities, are often treated at home. In this environment, modern communication systems represent a great support to implement Ambient Assisted Living platforms aimed at monitoring patients at home because they enable the seamless integration of heterogeneous sensing units, medical devices, and ubiquitous access to data. This article describes a specific smartphone-centric architecture where smartphones are employed not only as hubs of the health information but also as sensing, processing, and transmitting devices. Smartphones have both short-range (Bluetooth and WiFi employed for local information exchange) and long-range (GPRS, 3G/4G, and WiFi employed as Internet access) communication capabilities; information processing capabilities offered by modern platforms often equipped with different CPUs and with flexible and efficient software; and sensing capabilities implemented through sensors embedded into smartphones such as GPS receivers, accelerometers, microphones, and radio interfaces or through external sensors added to smartphones by cables or connected through local radio interfaces. The specific case of co-morbidities considered in this article implies the necessity to acquire a heterogeneous set of data from patients and from their environment. For this reason this article highlights the information processing capabilities of the introduced smartphone-centric platform. Audio, localization, and movement information processing have been evidenced as well as the specific implementations of these capabilities and their performance.

A smartphone-centric platform for remote health monitoring of heart failure

Abstract: Heart failure is a chronic disease that alternates intense and weak phases and requires repeated and frequent hospital treatments. The use of automatic instruments for a remote and ubiquitous monitoring of biological parameters relevant to heart failure pathophysiology offers new perspectives to improve the patients' quality of life and the efficacy of the treatment.

A Television Channel Real-Time Detector using Smartphones

Abstract: Recently, people have been interested in sharing what they are watching on TV, allowing the development of Social TV Applications often based on mobile devices. In this context, this paper proposes IRTR (Improved Real-Time TV-channel Recognition): a new method aimed at recognizing in real time (live) what people are watching on TV without any active user interaction. IRTR uses the audio signal of the TV program recorded by smartphones and is performed through two steps: i) fingerprint extraction and ii) TV channel real-time identification. Step i) is based on the computation of the Audio Fingerprint (AF). The AF computation has been taken from the literature and has been improved in terms of power consumption and computation speed to make the smartphone implementation feasible by using an ad hoc cost function aimed at selecting the best set of AF parameters. Step ii) is aimed at deciding the TV channel the user is watching. This step is performed using a likelihood estimation algorithm proposed in this paper. The consumed power, computation and response time, and correct decision rate of IRTR, evaluated through experimental measures, show very satisfying results such as a correct decision rate of about 95%, about 2s of computation time, and above 90% power saving with respect to the literature.

SPECTRA: A SPEech proCessing plaTform as smaRtphone Application

Abstract: In this paper, an Android SPEech proCessing plaTform as smaRtphone Application (SPECTRA) is presented. Such application, developed by the authors, has three main functions: i) Gender Recognition (GR), ii) Speaker Recognition (SR) and iii) Language Recognition (LR). All these recognition functions are performed simultaneously by using unsupervised Support Vector Machine (SVM) classifiers. An innovative point of this paper lies in the automatic re-training of the employed SVMs which are able to dynamically update themselves when a (new) audio from a (new) speaker is provided. This allow to build more robust classifiers, which results in better recognition performances. In terms of accuracy, the GR reaches about 98% of correct classifications, SR performs around 80% while LR shows an accuracy of about 74%.

Asset tracking architecture with Bluetooth Low Energy tags and ad hoc smartphone applications

Abstract: The paper describes an original architecture aimed at tracking assets within construction sites or similar contexts. The main components are: i) RFID tags, ii) Bluetooth Low Energy (BLE) tags and iii) smartphones. The core functions of the architecture are performed by two Android applications: the Asset Proximity Locator (APL) and the Wandering Objects Location Finder (WOLF). The key feature of the asset tracking function is the ability to maximize smartphone battery lifetime by switching on and off the GPS unit, thus guaranteeing that the smartphone can be used for an entire working shift. A detailed energy consumption analysis is carried out for each component of the architecture. The results achieved by simulations, concerning BLE tag detection probability, are presented and discussed.

A simple ultrasonic Indoor/Outdoor detector for mobile devices

Abstract: Context information is fundamental for mobile application. A system able to detect Indoor/Outdoor state switching can give useful information to upper-level applications permitting to improve their performance or reduce the computational load and consequently the lifetime of the smartphone. A localization application may exploit the Indoor/Outdoor information to smartly decide if using GPS (that performs well outdoors but poorly indoors) or other localization methods. In this paper we present an ultrasonic-signal-based Indoor/Outdoor detector for smartphones. The phone plays an ultrasonic ping by using its in-built speakers and records the echoes by using its microphone, therefore, no specific hardware is required to be added to the smartphone. The proposed detector shows good performance in terms of accuracy and latency.

Performance Comparison of Network Selection Algorithms in the Framework of the 802.21 Standard

Abstract: The diffusion of mobile devices, equipped with many different network interfaces, offers great benefits to mobile communications, by allowing the fruition of network services through different Radio Access Networks (RANs). On the other hand, the development of the IEEE 802.21 Standard, which facilitates the interoperability between different access networks, assures further performance improvements. In this scenario, Network Selection is the action of choosing the best Radio Access Network (RAN) among a set of available heterogeneous radio links. Within this topic, the main contribution of this paper is a performance comparison, obtained through a simulator developed by using Network Simulator 2, among different network selection algorithms, within the framework of the 802.21 standard.

Hybrid Simulated-Emulated Platform for Heterogeneous Access Networks Performance Investigations

Abstract: A communication network composed of heterogeneous access technologies can assure some benefits to mobile users. To exploit these benefits it is crucial to implement control techniques and algorithms to assure a proper level of Quality of Service (QoS). Performance studies are necessary to validate the proposed solutions before implementing them in real networks. Network simulators and emulators are useful tools. The main contribution of this paper is the description of a tool developed by the authors and called Hybrid Simulated and Emulated Platform (HySEP). HySEP is used to analyse the performance of different wireless networks such as Long Term Evolution (LTE) and Wi-Fi, simulated by using Network Simulator 3 (ns-3), connected to a transport network which implements the Differentiated Service (DiffServ) protocol, emulated through a group of virtual PCs. HySEP enables the creation of a simulated mobile node which implements heterogeneous network interfaces and can execute vertical handover while it is communicating with a real node. HySEP validation tests represent a further contribution of this paper.

Cooperative Application Layer Joint Coding and rate allocation techniques for video transmissions over satellite channels through smartphones

Abstract: This paper considers video transmissions through Smartphones in scenarios of emergency networks where satellite links are employed. Unfortunately, satellite channels may be affected by attenuation and fading, causing significant and frequent variations of the link quality. For this reason, static compression, coding and resource allocation are not optimal solutions to guarantee a satisfactory level of Quality of Experience: we propose to apply two techniques: i) a dynamic transmission rate allocation able to assign resources to the links according to their conditions; ii) an application layer joint coder for video transmission capable of adaptively compressing and protecting the transmitted video frames so recovering losses. The performance investigation of the proposal has been carried out through emulation and the obtained results are satisfactory and open the doors to future development of the proposal.

An Ns-3 based simulative and emulative platform

Abstract: This chapter contains the description of a simulative/emulative platform developed by the authors and called the “Hybrid Simulative-Emulative Platform (HySEP).” It has been designed and built to simulate long term evolution (LTE) networks by using Network Simulator 3 (ns-3) and to emulate a backhaul network that implements the Differentiated Service (DiffServ) solution to guarantee Quality of Service (QoS). The former composes the Simulated Network Segment (SNS), the latter the Emulated Network Segment (ENS). The use of ns-3 assures a detailed LTE simulative model and an effective mechanism to connect the simulated scenario with real network nodes and links. Moreover, this platform enables the creation of a heterogeneous network through the exploitation of personal computers and free software without using any ad-hoc hardware. HySEP makes possible testing different network configurations, limiting costs and using technologies such as LTE whose real implementation is hardly applicable inside a research laboratory. The tool can be completely configured and used remotely through Internet connections.

Poster: Detecting if a Smartphone is Indoors or Outdoors with Ultrasounds

Abstract: Context information is fundamental for mobile application. A system able to detect if a smartphone is indoors or outdoors can give useful information to upper-level applications, permitting to improve their performance or reduce the computational load and consequently the lifetime of the smartphone battery. For example, GPS provides an accurate location reference in the outdoor environment while it performs poorly inside buildings. The proposed Indoor/Outdoor (IO) detector can provide a useful essential information to a localization application that can check whether the user is outdoors before turning on the GPS interface and decide not to turn it on and use other localization methods if the user is detected indoors. In mobile data services, mobile phones normally observe more WiFi access points (APs) with strong signals inside buildings, whereas it is unlikely to have good WiFi connections in outdoor environments. Therefore, knowing whether the smartphone is indoors or outdoors can help to make smarter decisions regarding whether to perform or not AP scans. Although it is clear that various applications may benefit from accurate and prompt indoor/outdoor information, the research work on indoor/outdoor detection of mobile devices is still lacking. There are mainly two techniques to perform such detection. One is to use GPS and its signal quality as a cue to infer if the user is indoor. This technique is proven to be highly power consuming. Another technique is to leverage the sensors which the smartphone is equipped with. IO detection can be done by exploiting lightweight sensors such as the light sensor, the radio interface and the magnetism sensor [1]. The proposed IO detector is an active system. The phone periodically emits an ultrasonic ping using its in-built speakers and continuously listens for the echoes through its microphone. It is impossible to identify the direction of the echoes being the microphone (as well as the phone speakers) non-directional. The idea is that indoors the number and the intensity of the echoes should be higher than outdoors due to the higher number of obstacles. Translating such an idea into a practical Indoor/Outdoor detector means finding those features that model such behaviour. The proposed

A Heuristic Attack Method to PRH-Based Audio Copy Detectors

Abstract: Often copyrighted multimedia files are uploaded and shared online. To avoid the unregulated spread of such material many copy detectors have been developed in order to deny the possibility to upload, and consequently make available, copies of copyrighted contents. A widely referenced fingerprint method for content-based audio identification is the Philips Robust Hash (PRH) . This paper introduces a simple but effective attack technique capable to defeat a PRH fingerprint-based audio copy detector without significantly affecting the signal quality. It is a heuristic method that adds a suitable distortion to the original audio signal, so that the modified signal is not detected as a copy of the original one but is perceptively very similar to it. The quality of the modified signal has been evaluated in terms of a distortion measure based on a mathematical model of the human auditory system and of the Peak Signal-to-Noise Ratio (PSNR). The attack method has shown a promising success rate.