Showing papers by "Igor Bisio published in 2012"

Power Saving Bandwidth Allocation over GEO Satellite Networks

Abstract: The problem of bandwidth allocation may be simply stated, independently of the target of the allocation: an amount of bandwidth must be shared among different entities. Each entity receives a portion of the overall bandwidth. Bandwidth allocation may be formalized as a Multi-Objective Programming (MOP) problem where the constraint is the maximum available bandwidth. The objectives of the allocation such as loss and power may be modelled through a group of objective functions possibly contrasting with each other. It is quite intuitive that using more bandwidth will reduce losses, but also that transmitted power will increase with the bandwidth. Which is the balance among these needs? This letter proposes an extended model for bandwidth allocation [1] and uses a modified version of a MOP-based bandwidth allocation to provide a possible solution to the mentioned balancing problems.

Smartphone-based user activity recognition method for health remote monitoring applications

Abstract: In the framework of health remote monitoring applications for individuals with disabilities or particular pathologies, quantity and type of physical activity performed by an individual/patient constitute important information. On the other hand, the technological evolution of Smartphones, combined with their increasing diffusion, gives mobile network providers the opportunity to offer real-time services based on captured real world knowledge and events. This paper presents a Smartphone-based Activity Recognition (AR) method based on decision tree classification of accelerometer signals to classify the user’s activity as Sitting, Standing, Walking or Running. The main contribution of the work is a method employing a novel windowing technique which reduces the rate of accelerometer readings while maintaining high recognition accuracy by combining two single-classification weighting policies. The proposed method has been implemented on Android OS smartphones and experimental tests have produced satisfying results. It represents a useful solution in the aforementioned health remote applications such as the Heart Failure (HF) patients monitoring mentioned below.

Capacity bound of MOP-based allocation with packet loss and power metrics in satellite communications systems

Abstract: The task of a capacity allocation policy is to determine the optimal quantity of capacity that has to be shared among the transmitting entities. In this work the allocation problem is modelled by the Multi Objective Programming (MOP) theory. In particular, an allocation criterion based on the L p -problem is proposed to find out a capacity allocation, among Earth Stations, representative of a compromise if Packet Loss Probability and Transmitted Power are taken into account as performance metrics. The paper also discusses the existence of a capacity allocation, called Capacity Bound, on which the performance converges independently of the overall capacity available C TOT . A performance analysis, carried out through simulations and under different satellite channel conditions, is finally proposed to investigate the allocation criterion performance and to show the Capacity Bound existence.

Trainingless fingerprinting-based indoor positioning algorithms with Smartphones using electromagnetic propagation models

Abstract: Recent multimedia and location-based services (LBSs) employ information about location, orientation, and context of a mobile device. Moreover, the wide spread adoption of Smartphones, usually equipped with powerful processors, accelerometers, compasses, and Global and Hybrid Positioning Systems (GPS/HPSs) receivers, has favored the increasing of location- and context-based services over the last years. In this work a Wi-Fi fingerprint-based indoor positioning techniques is considered. It is aimed at supporting possible location aware services. The main novelty introduced in this paper concerns the training phase, which is usually needed by these techniques. In our approach, the training phase is avoided, since opportune simulative propagation models of the environment in which the algorithm are working are introduced. The resulting technique allows exploiting the accuracy of the fingerprinting approaches and, simultaneously, avoids the heavy training phase, which represents one of the main drawbacks of such techniques.

Opportunistic estimation of television audience through smartphones

Abstract: Television audience estimation is an important task for advertisement placement. In this paper we present a system based on a client-server architecture able to recognize a live television show. The clients are implemented throughout smartphones, thus a well known audio fingerprint algorithm has been modified to fit smartphone needs. To reach this aim, the optimization of an ad-hoc cost function has been introduced. Server and client are generally far from being synchronized, due to the variety of broadcasting media (aerial, satellite or streaming over the Internet) leading to different and unpredictable delays. For this reason, we present a new likelihood estimate designed to overcome the lack of synchronization issue.

Smartphone-based automatic place recognition with Wi-Fi signals for location-aware services

Abstract: Recent multimedia and location-based services (LBSs) employ information about location, orientation and context of a mobile device. Moreover, the wide spread adoption of Smartphones, usually equipped with powerful processors, accelerometers, compasses and Global and Hybrid Positioning Systems (GPS/HPSs) receivers, has favored the increasing of location- and context-based services over the last years. In this work a novel Location Recognition approach aimed at supporting location aware services, in particular Check-In services, is presented. The proposed method uses both the GPS/HPS positioning information and, in an opportunistic way, the presence of Wi-Fi Access Points (APs). The method is based on the concept of radio FingerPrint (FP) whose definition proposed in this paper, to the best of authors' knowledge, has never been applied previously. The method is suited to be employed where traditional approaches — usually based only on GPS/HPS − fail, as in case of indoor or dense urban environments. Finally, the proposal, practically realized over different Android OS Smartphones, has been tested in terms of performance. The experimental results are very satisfying and open the doors to a wide employment of the method.

Mobile Sensing of User’s Motion and Position Context for Automatic Check-in Suggestion and Validation

Abstract: Users are increasingly interested in mobile social applications that allow them to share opinions, comments and votes about places (restaurants, shops, etc.). Among these, check-in applications are spreading rapidly. In this paper we illustrate a system able to automatically validate users’ check-in in a place exploiting device’s sensors and inferred knowledge of context (motion activity, nearby friends). Additionally, the system allows check-in suggestion to users staying in a place for a required amount of time. A description of the service scenario, of the architecture and its technical components is given, focusing on how raw context data from accelerometer onboard the device is used to recognize users’ motion situation and how it is combined with GPS position to validate check-ins.

Personal Satellite Services

Abstract: Future Personal Satellite Services (PSATS) represent a trendy research area due to its importance that it may have in the our daily lives. Being the personal services related to users, they deal with services and devices whose nature is pervasive. All these concepts have been clearly addressed in the Personal Satellite Services 2011 Conference (PSATS’11) through different interesting talks and in this special issue where original contributions selected from the set of papers presented to PSATS’11, have been extended and published after a severe two-round review process. In more detail, among the topics that deal with Personal Satellite Services, this special issue focuses on four topics: i) dual frequency receivers performance for Galileo-based tracking services; ii) integrated radio systems; iii) transport layer protocols; iv) security issues in Delay Tolerant Networks. Received on 20 March 2012; published on 29 March 2012 Copyright © 2011 Bisio and Hu, licensed to ICST. This is an open access article distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/3.0/), which permits unlimited use, distribution and reproduction in any medium so long as the original work is properly cited. doi: 10.4108/trans.ubienv.2012.e2