Alejandro Canovas

Saving energy and improving communications using cooperative group-based Wireless Sensor Networks

Wireless Sensor Networks (WSNs) can be used in many real applications (environmental monitoring, habitat monitoring, health, etc.). The energy consumption of each sensor should be as lower as possible, and methods for grouping nodes can improve the network performance. In this work, we show how organizing sensors in cooperative groups can reduce the global energy consumption of the WSN. We will also show that a cooperative group-based network reduces the number of the messages transmitted inside the WSNs, which implieasa reduction of energy consumed by the whole network, and, consequently, an increase of the network lifetime. The simulations will show how the number of groups improves the network performance.

A hybrid stochastic approach for self-location of wireless sensors in indoor environments.

Indoor location systems, especially those using wireless sensor networks, are used in many application areas. While the need for these systems is widely proven, there is a clear lack of accuracy. Many of the implemented applications have high errors in their location estimation because of the issues arising in the indoor environment. Two different approaches had been proposed using WLAN location systems: on the one hand, the so-called deductive methods take into account the physical properties of signal propagation. These systems require a propagation model, an environment map, and the position of the radio-stations. On the other hand, the so-called inductive methods require a previous training phase where the system learns the received signal strength (RSS) in each location. This phase can be very time consuming. This paper proposes a new stochastic approach which is based on a combination of deductive and inductive methods whereby wireless sensors could determine their positions using WLAN technology inside a floor of a building. Our goal is to reduce the training phase in an indoor environment, but, without an loss of precision. Finally, we compare the measurements taken using our proposed method in a real environment with the measurements taken by other developed systems. Comparisons between the proposed system and other hybrid methods are also provided.

A smart communication architecture for ambient assisted living

Intelligent systems and communication technologies have experienced huge advances in the last few years. AAL can benefit from mixing both research fields. This article presents an intelligent communication architecture for AAL. It uses artificial intelligence to process the information gathered from several types of communication (e.g., wireless sensor networks, wireless ad hoc networks, wireless mesh networks) over any type of communication technologies (e.g., device-to-device, machine-to-machine, sensor-actuator), know what is happening in the network, and detect if elderly people need assistance. The article shows the main intelligent algorithms included in the AAL system and the developed software application. Several real measurements validate the operation of our proposal.

A QoE management system to improve the IPTV network

One of the biggest problems of the IPTV providers is to offer enough quality of experience (QoE) to their customers. The minimum bandwidth in the access network required to provide IPTV services, jointly with the necessity to guarantee the QoE to the customers, creates the need for new type of algorithms to satisfy the network requirements. Apart from the parameters that depend on the application aspect and design, the users QoE mainly depends on the video quality (VQ), which can be affected by the network parameters (jitter, delay, lost packets, etc.), and on other parameters, such as zapping time and synchronization time. In this paper, we implement several benches to know how each measurable parameter affects the users QoE. Taking into account these parameters, we propose an analytical expression for the QoE calculation. Then, the paper presents a network management algorithm that takes into account the information received by the user to take the appropriate actions and vary some features of the IP network to provide enough IPTV QoE to the customer. Finally, we measure how one of the actions taken by our system affects the network performance and the VQ. Copyright

A QoE Management System for Ubiquitous IPTV Devices

The use of the triple-play services is growing up very quick in the recent years. This has come by the hand of the higher bandwidth offered in broadband access by the service providers. IPTV is the service that has been experienced more request, although it was the least developed. One of its biggest problems is to meet enough quality of experience (QoE) for the customers. This paper presents a QoE management system to guaranty enough IPTV QoE to the customer independently of its type of connection (wired or wireless). The User’s QoE depends, among others, on the video quality, the zapping time and the synchronization time. The system calculates the user’s QoE and notifies him which networks are available for him and have higher QoE. Then, the user decides to roam to that network. The system allows providing ubiquity to multi-network devices.

Group-based protocol and mobility model for VANETs to offer internet access

Abstract Some public transport vehicles embed devices that allow passengers to connect to Internet while traveling. These vehicles are true mobile Internet access zones inside public paths. These zones could be used by other vehicles moving close to them in order to have Internet access. At the same time, other vehicles in the influence area could be used as relay nodes which would increase this access area. In this paper, we present a group-based protocol and mobility model for vehicular ad hoc networks (VANETs) where each public transport vehicle forms a group of vehicles. They can access and allow access to Internet though the public transport vehicle. Each vehicle is moving inside the group and can leave and join any group at will, while all groups are moving. First, we will show the algorithm and protocol to achieve our purpose. Then, we will study the probability of having Internet access in order to demonstrate that it is a feasible proposal. Finally, we simulate a study case based on real values in order to obtain the performance of our proposal in terms of several network parameters such as the number of hops per route, the network traffic, the page response time, network delay, network load and so on.

An Integrated IoT Architecture for Smart Metering

Advanced meter infrastructures (AMIs) are systems that measure, collect, and analyze utilities distribution and consumption, and communicate with metering devices either on a schedule or on request. AMIs are becoming a vital part of utilities distribution network and allow the development of Smart Cities. In this article we propose an integrated Internet of Things architecture for smart meter networks to be deployed in smart cities. We discuss the communication protocol, the data format, the data gathering procedure, and the decision system based on big data treatment. The architecture includes electricity, water, and gas smart meters. Real measurements show the benefits of the proposed IoT architecture for both the customers and the utilities.

A network management algorithm and protocol for improving QoE in mobile IPTV

Last improvements on video codecs, jointly with the use of optimized transport protocols, have brought us to provide IPTV in wireless networks. Moreover, cellular phone users are being accustomed to have all Internet services in the mobile device, through 3G or WiFi technology, with the same quality of experience (QoE) than in any desktop computer or laptop with broadband Internet connection. In this paper we present a network management algorithm and protocol for ubiquitous networks based on the QoE of the end user. First, we explain the developed protocol and algorithm, that uses the information provided by the mobile device and the bandwidth, jitter, delay and packet loss of the end user, in order to decide which is the most appropriate video features and the best coding technique to deliver the video streams. A video controller server decides which video server, from a farm of servers, is the best one for each case. We show the algorithm performance when each coding technique is changed in the server due to transcoding process, and the network performance in terms of jitter, delay and lost packets received by the end user when each coding technique is selected by the video controller server.

A Framework for Obesity Control Using a Wireless Body Sensor Network

Low-cost low-power consumption small wireless sensor devices have empowered the development of wireless body area networks (WBANs). In WBANs many sensors are attached to human body for sensing particular health related information to improve healthcare and quality of life. Obesity is one of the most common problems all over the world, which is amongst main causes of cardiovascular diseases. In this research, we explore hardware and software architecture of WBAN for obesity monitoring. The proposed framework consists of few sensor nodes that monitor body motion, calories calculator, and a personal server running on a personal smart phone or a personal computer. The focus of this research is to make obesity patients easier to get rid of this disease.

Vertical WLAN handover algorithm and protocol to improve the IPTV QoS of the end user

The appearance of several IEEE 802.11 variants made possible the availability of many wireless local area network access options for end users in the same location. Network requirements for IPTV service become higher when the quality of the delivered video is higher. Moreover, in wireless networks the network performance is highly degraded when there is high number of users. In this paper, we propose a protocol and algorithm that makes to handover IPTV users to the best available WLAN when the QoS parameters received by the end user reaches a threshold. It guarantees anytime the highest QoS for the user. Real measurements show that the vertical handover performed by the user is performed without noticing it. This algorithm is highly appropriate for mobile users.