In this paper, we propose an unobtrusive method and architecture for monitoring a person’s presence and collecting his/her health-related parameters simultaneously in a home environment. The system is based on using a single ultra-wideband (UWB) impulse-radar as a sensing device. Using UWB radars, we aim to recognize a person and some preselected movements without camera-type monitoring. Via the experimental work, we have also demonstrated that, by using a UWB signal, it is possible to detect small chest movements remotely to recognize coughing, for example. In addition, based on statistical data analysis, a person’s posture in a room can be recognized in a steady situation. In addition, we implemented a machine learning technique (k-nearest neighbour) to automatically classify a static posture using UWB radar data. Skewness, kurtosis and received power are used in posture classification during the postprocessing. The classification accuracy achieved is more than 99%. In this paper, we also present reliability and fault tolerance analyses for three kinds of UWB radar network architectures to point out the weakest item in the installation. This information is highly important in the system’s implementation.

Integrating the standard coverage of traditional macrocells with cells of reduced dimensions (i.e., small cells) is considered one of the main enhancements for Long Term Evolution systems. Small cells will be overlapped with macrocells and possibly also with each other in areas where wider coverage capability and higher throughput are needed. Such heterogeneous network deployment presents many potential benefits but also some challenges that need to be resolved. In particular, multi-antenna techniques and processing in the spatial domain will be key enabling factors to mitigate these issues. This article presents different small cell deployment approaches: sharing the same frequency bands with the macrocell, or using separated higher frequency bands. For each approach, the benefits of beamforming are discussed.

Wireless communications have received much attention during the last decades due to easy implementation, the possibility of delivering multimedia services to rural communities, and the suitability for public safety and for communicating in emergency situations. In particular, a wireless network designed for an emergency scenario must be capable of monitoring sensitive areas and must enable people to connect immediately after a disaster. This article discusses the main features of a wireless network that aims to interconnect several heterogeneous systems and provide multimedia access to groups of people to better monitor a specific area, to have a fast response in case of a disaster, and to efficiently coordinate all of the forces during the disaster management phase.

WiMax is one of the most important technologies for providing a broadband wireless access (BWA) in a metropolitan area. The use of OFDM transmissions has been proposed to reduce the effect of multipath fading in wireless communications. Moreover, multiple access is achieved by resorting to the OFDMA scheme. Adaptive subcarrier allocation techniques have been selected to exploit the multiuser diversity, leading to an improvement of performance by assigning subchannels to the users accordingly with their channel conditions. A method to allocate subcarriers is to assign almost an equal bandwidth to all users (fair allocation). However, it is well known that this method limits the bandwidth efficiency of the system. In order to lower this drawback, in this paper, two different adaptive subcarrier allocation algorithms are proposed and analyzed. Their aim is to share the network bandwidth among users on the basis of specific channel conditions without loosing bandwidth efficiency and fairness. Performance comparisons with the static and the fair allocation approaches are presented in terms of bit error rate and throughput to highlight the better behavior of the proposed schemes in particular when users have different distances from the BS.

The evolution toward 5G is driven by the need of providing a wide range of services differing on needed network functionalities, performance requirements, type of devices, and going beyond the human-type communications. Such a wide variety of requirements cannot be always met through a common network setting, hence, high network flexibility and scalability are required. Network slicing allows the operation of multiple end-to-end logical networks on a common physical infrastructure: each network slice is tailored to best support a specific service. Network slicing on the radio access network (RAN) domain is challenging. In order to manage the scarce radio resources, RAN slicing requires flexibility, efficient resource sharing, and customization. Hence, dynamic resource management presents unique challenges, it has to take into account different issues that can also be in contrast with each other. This paper proposes a two-layer scheduler for an efficient and low complexity RAN slicing approach in actual systems. It is shown that simply setting some parameters it is possible to achieve different trade-offs between isolation and efficiency, allowing the management of priority and customization. The performance of the proposed method has been compared with other benchmark approaches to show good behavior and the flexibility of the proposed approach.

Broadband wireless technologies are becoming more and more pervasive in several fields of application to supply new services and to satisfy operational constraints. Among them, this article deals with the use of WiMAX technology in future air traffic management system. This technology is expected to increase the safety and to allow the exchange of large volumes of data among heterogeneous users, including aircraft. In particular, Eurocontrol and ICAO identified a WiMAX-based technology for communications on the airport surface, named Aeronautical Mobile Airport Communication System (Aero- MACS). The scope of this article is to provide an overview of AeroMACS, with a description of its main features, requirements, PHY and MAC profile choices, and related network architecture. Finally, the article highlights some open issues for AeroMACS that represent critical aspects and require, at this time, additional investigation.