Catálogo de publicaciones - libros

Time of arrival (TOA) based geolocation schemes for indoor multi-hop environment are investigated and compared to some of conventional geolocation schemes such as least squares (LS) or residual weighting (RWGH). The multi-hop ranging involves positive multi-hop noise as well as non-line of sight (NLOS) and Gaussian measurement noise, so that it is more prone to ranging error than one-hop range. In this paper, RWGH algorithm is modified by adapting weighted residual normalization considering the number of hops taken to measure each ranging. The iterative positive noise mitigation schemes are further developed by using distance enlargement test (DET) to mitigate the multi-hop ranging noise. Simulation results show that the proposed modified RWGH algorithms show 5 to 25% smaller average estimation error compared to LS and RWGH for both positive noise mitigation and no mitigation cases, and the positive noise mitigation schemes provide 28 to 42% error mitigation compared to no mitigation schemes.

The paper focusses on the use of wireless networks, with special emphasis on Wi-Fi, in the manoeuvering and apron areas of an airport to control the ground vehicles movements in those areas and, consequently, to improve user safety, efficiency of operations and airport security. The use of Wi-Fi for these purposes constitutes a novel approach in an airport environment. Other wireless networks, namely CDMA and Tetra, are also experimented in this project as a lower bit-rate alternative to Wi-Fi. The platform consists of an on-board system in each vehicle, a centralised ground system and wireless networks to allow the communication between the vehicles and ground system. The architecture, protocols and network configurations in use are analysed as well as the respective deployment made in the airport of Porto in Portugal.

Mobile RFID (Radio Frequency Identification) is a new application to use mobile phone as RFID reader with a wireless technology and provides new valuable services to user by integrating RFID and ubiquitous sensor network infrastructure with mobile communication and wireless internet. However, there are an increasing number of concerns, and even some resistances, related to consumer tracking and profiling using RFID technology. Therefore, in this paper, we describe the security analysis and implementation leveraging globally networked mobile RFID service which complies with the Korea’s mobile RFID forum standard.

In order to provide suitable blood transfusion samples to patients, the blood bag should be kept at a uniformly maintained temperature to prevent deterioration during transportation. Therefore, this paper presents a blood monitoring and management system for use in hospitals. This system may continuously report the temperature of the blood bank refrigerator, track the location of a blood bag to increase staff operation efficiency, and can confirm that the assigned blood bag was transported to the intended patient in need of transfusion. We developed and demonstrated the clinical usability of the combined blood temperature management and tracking system using a ubiquitous sensor network and RFID (Radio Frequency Identification) technology.

The third generation wireless networks and wireless local networks possess complementary characteristics. Recently, there has been significant interest in providing algorithms and specifications that enable their inter-operability. In this paper we propose a novel cross-network, cross-layer algorithm that jointly performs 3G resource allocation and ad-hoc mode WLAN routing towards effectively increasing the performance of the 3G system. The metrics used in this joint design ensures that multi-user diversity is exploited without causing user starvation in the 3G system and the WLAN assistance does not cause an unfair treatment to any of the mobiles from a battery usage point of view. Furthermore, the design attempts to select the WLAN route so that the assistance does not become a major part of the internal WLAN traffic.