0000000000088408
AUTHOR
Jaime Lloret
showing 24 related works from this author
A Survey on Proxy Mobile IPv6 Handover
2016
[EN] As wireless technologies have been improving in recent years, a mobility management mechanism is required to provide seamless and ubiquitous mobility for end users who are roaming among points of attachment in wireless networks. Thus, Mobile IPv6 was developed by the Internet Engineering Task Force (IETF) to support the mobility service. However, Mobile IPv6 is unable to fulfill the requirements of real-time applications, such as video streaming service and voice over IP service, due to its high handover (HO) latency. To address this problem, Proxy Mobile IPv6 (PMIPv6) has been introduced by the IETF. In PMIPv6, which is a network-based approach, the serving network controls mobility m…
A Secure Spontaneous Ad-Hoc Network to Share Internet Access
2009
In this paper, we propose a secure spontaneous ad-hoc network to grant the access of the users to surf the Web. The paper shows the description of our proposal, the procedure of the nodes involved in the system and the designed messages. We also validate the success of our proposal through several simulations and comparisons with a regular architecture. The proposal has been developed with the main objective of improving the communication and integration between different study centers of low resource communities.
A Group-Based Architecture for Wireless Sensor Networks
2007
Many routing protocols for ad-hoc networks and sensor networks have been designed, but none of them are based on groups. We propose to divide the network into several groups of sensors. When a sensor send data to other groups, the data has to arrive just to one sensor from each group, then they propagate it to the rest of sensors in their groups. We have simulated our proposal for different types of sensor topologies to know which type of topology is the best depending on the number of sensors in the whole network or depending on the number of interior sensors. We have also simulated how much time is needed to propagate information between groups. The application areas for our proposal coul…
Does ns2 Really Simulate MPLS Networks?
2008
Multi Protocol Label Switching (MPLS) is being used in many corporate networks and public infrastructures and as a backbone technology of many Autonomous Systems. Because of its importance, what is needed is to find out simulators able to simulate MPLS networks whose results reflect the real environment as much as possible. In this article, we will show real measurements from the Railway Infrastructure Administrator (ADIF, the Spanish railway infrastructure manager) MPLS network and we will compare them with the results obtained by the freeware simulator ns2. We will check the level of reliability provided by the simulator and we will know under which parameters its results will be similar …
Two Levels SPF-Based System to Interconnect Partially Decentralized P2P File Sharing Networks
2005
Partially decentralized P2P (PDP2P) networks are a subset of P2P networks. Roles of nodes are different according to their functionality in the network. Nowadays, there are many PDP2P networks, with different characteristics. It is necessary to find a way to join those autonomous networks. We have not found any interconnection system, so in this article we present a new hierarchical system for interconnecting peers from different PDP2P networks. It will allow sharing data, content and resources between networks. It can be employed between sensor networks, P2P networks, and generally, overlay networks. Oldest superpeers or brokers with higher bandwidth in the PDP2P network will belong to hig…
A fault-tolerant protocol for railway control systems
2006
Railway control systems are largely based on data communication and network technologies. With the adoption of Ethernet-IP as the main technology for building end-to-end real-time networks on railway control systems, the requirement to deliver high availability, quality and secure services over Ethernet has become strategic. Critical real-time traffic is generally penalized and the maximum restoration time of 50 msec sometimes is exceeded because of real-time applications hangings, so passengers' safety could be committed. It occurs on more than twenty percent of critical fail tests performed. Our main goal is to minimize restoration time from the application point of view. This article des…
A User-Balanced System for IP Telephony in WLANs
2008
Wireless IP telephony is becoming very popular between the users of large wireless local area networks (WLANs). This increment has been mainly caused because it allows cost savings. Although, large WLANs use to provide high availability and redundancy, WLANs lack on the available throughput when there are many IP telephony users. In this paper we present a system that reallocates IP telephony devices when the system detects that an AP is overloaded. The algorithm and the frames used for our proposal are described. Measurements taken show how the bandwidth consumed is transferred from an access point to another when our proposal is running. Finally, we show the time needed to re-associate re…
Emerging Trends, Issues, and Challenges in Big Data and Its Implementation toward Future Smart Cities
2017
The articles in this special section focus on Big Data as it impacts future smart cities. The world is experiencing a period of extreme urbanization. Moreover, this process will continue, and the global urban population is expected to double by 2050. Smart city has been proposed to improve the efficiency of services and meet residents’ needs for better quality of life. Essentially, smart city integrates the Internet of Things and emerging communication technologies such as fifth generation (5G) solutions to manage the citys’ assets, including transportation systems, hospitals, water supply networks, waste management, and so on. Therefore, smart city is driving innovation and new technologie…
A New Neighbour Selection Strategy for Group-Based Wireless Sensor Networks
2008
In any type of networks a neighbour selection method is needed to form the topology of the network and to know which node the information has to be sent to reach a destination. Nowadays, several selection strategies exist that are based on different aspects and mainly designed to work in common networks. In this paper we will show our study about those different methods and, then we show the development of a suitable neighbour selection strategy for group-based wireless sensor networks (WSN) that is based on a capacity parameter defined by us and the new neighbour distance. We also present the proposal architecture for WSNs and the protocol when a new node joins a group and has to select it…
How the Atmospheric Variables Affect to the WLAN Datalink Layer Parameters
2010
There are many issues that affect to WLAN connections (walls, vegetation, rain, objects in the Fresnel zone, etc.). Network designers and telecommunication practitioners must take them into account when they are planning wireless connections between devices. Some studies have demonstrated the implication of the atmospheric variables in the frequency attenuation and in the line of sight of the waves. But, to the extend of our knowledge, there is not any work published that relates the atmospheric variables with the datalink layer parameters of the WLANs. We must take into account that the datalink layer allows us to measure quite more parameters than the physical layer. After a review of the…
Improving IoT Communications Based on Smart Routing Algorithms
2018
International audience; Due to the recorded success by Internet of Things (IoT) technology, more and more domains use it as a communications and exchange network such as e-health, smart cities, vehicles, etc. IoT don’t stop integrating an important number of components and objects that are characterized by their complexity and heterogeneity. Such constraints make the existing routings protocols unsuitable for IoT communications. To accomplish all the expected tasks and satisfy the user services, it is important to guarantee a quality of communication that answers to the requirements of the various applications in terms of data and processing (availability, integrity, efficiency, etc.). The …
A comprehensive survey of multi-view video summarization
2021
[EN] There has been an exponential growth in the amount of visual data on a daily basis acquired from single or multi-view surveillance camera networks. This massive amount of data requires efficient mechanisms such as video summarization to ensure that only significant data are reported and the redundancy is reduced. Multi-view video summarization (MVS) is a less redundant and more concise way of providing information from the video content of all the cameras in the form of either keyframes or video segments. This paper presents an overview of the existing strategies proposed for MVS, including their advantages and drawbacks. Our survey covers the genericsteps in MVS, such as the pre-proce…
Recent advances in green industrial networking [Guest Editorial]
2016
The articles in this special section focus on green industrial networking. Due to the explosive increase in energy usage, it is essential that governmental and industrial institutions address this problem. Therefore, the development of green and low-carbon economy has recently become a hot issue in the industry. It is envisioned in such cases to meet the growing demands for industrial networking with limited resources. This is considered one of the challenges that needs to be addressed. Addressing such key problems will hopefully allow us to reach the realization of sustainable development. We believe that network technologies will be critical and will greatly contribute to achieving large-…
TCP Performance in Mobile Ad hoc Networks
2013
International audience; In this paper, we present a survey of TCP (Transmission Control Protocol) protocol for better performance in the MANET (Mobile Ad Hoc Network). After a short presentation of the main features of TCP, we give the most important problems from which TCP suffer in MANET. We present after that some approaches proposed in the literature in order to improve its performance. Our paper contains also a performance evaluation of TCP NewReno and TCP Vegas transport protocols under AODV and DSR routing protocols. The simulations are conducted under varying conditions of number of TCP connections, number of nodes and mobility.
Design and Implementation of ForCES Protocol
2017
This paper proposes the design and implementation of the ForCES protocol, specifically FP logical point of the ForCES architecture, which is strictly the communication between the CE (Control Element) and the FE (Forwarding Element). It is a flexible and reprogrammable architecture that is established within the specifications issued and defined by the ForCES working group, and consists of elaboration of a protocol that carries information between both elements. In order to comprobate the correct functioning of the implemented the ForCES protocol, is we provide a network testbed scenario, which consist an application client-server. Each device has equipped with the application which based o…
A Group-Based Protocol for Large Wireless AD-HOC and Sensor Networks
2008
Many routing protocols for ad-hoc networks and sensor networks have been designed, but none of them is based on groups. It is known that grouping nodes gives better performance to the group and to the whole system, thereby avoiding unnecessary message forwarding and additional overheads. We propose an approach where the network is split into several groups of sensors where connections between groups are established as a function of the proximity and the neighbor's available capacity (based on the sensor's energy). In this paper the network architecture is described with its mathematical description and the messages that are needed to proper operation. It is also simulated how much time is n…
Using MANET Protocols in Wireless Sensor and Actor Networks
2008
Although there are several routing protocols for wireless sensor and actor networks (WSAN), none of them have became standard. Now, there are several standard protocols for mobile ad hoc networks (MANET) that have been developed for devices with higher computing features than the sensor nodes. On the other hand, one of the main characteristics of the MANET protocols is their scalability. In this paper, we show the performance of a WSAN, when MANET protocols are used, for several topologies. We will discuss and evaluate which standard protocol is the best one depending on the number of nodes in the topology and depending on their mobility. Finally we will show their comparison. As far as we …
A Multisensor Proposal for Wireless Sensor Networks
2008
Every sensor node in a wireless sensor network (WSN) has a microcontroller, a transmitter/receiver and a sensor. It is able to acquire data from specific point in a real environment and transmit it through the WSN. Sometimes it is useful to gather different type of data from the same place in order to obtain a final result. In the related literature, very few works are about sensing different parameters using a unique sensor. In this paper we propose a Wireless IP multisensor that is able to gather several types of data from the environment and transmit the result of their combination. Our proposal decision has being mainly based on its development costs, its expansion capacity and its flex…
Software Requirements for Ubiquitous Ad Hoc Mobile Networks: An Example of a Bluetooth Application
2009
In contrast with the simple and elegant concept of global computing, also called ubiquitous computing - where daily life objects get now computing capacity and interact among them to provide a wide range of services to users - a major difficulty is arising with the software engineering process to develop applications for these devices. This article discusses the additional parameters that should be taken into account when designing and developing software for ubiquitous devices in ad-hoc networks. In these networks the mobility of the devices could increase the complexity of the requirements to be considered. As a case study, we present a Bluetooth application that has been developed to ful…
A group-based wireless body sensors network using energy harvesting for soccer team monitoring
2016
[EN] In team-based sports, it is difficult to monitor physical state of each athlete during the match. Wearable body sensors with wireless connections allow having low-power and low-size devices, that may use energy harvesting, but with low radio coverage area but the main issue comes from the mobility. This paper presents a wireless body sensors network for soccer team players' monitoring. Each player has a body sensor network that use energy harvesting and each player will be a node in the wireless sensor network. This proposal is based on the zone mobility of the players and their dynamism. It allows knowing the physical state of each player during the whole match. Having fast updates an…
Multicast TV over WLAN in a University Campus Network
2009
One of the multimedia services offered by the campus network of the Polytechnic University of Valencia is TV over IP. This service works well in the devices connected directly to the wired network but we have detected some problems when the receivers access to the campus network through wireless IEEE 802.11, especially when devices roam across the Campus. In this paper we propose and evaluate a server-based solution to minimize the packet loss and reduce the lack of service when the mobile devices roam from an Access Point to another Access Point in the wireless network. This solution uses a location system to modify the behaviour of standard multicasting protocols in order to get a near-se…
Context-aware vehicular cyber-physical systems with cloud support: architecture, challenges, and solutions
2014
[EN] The advances in wireless communication techniques, mobile cloud computing, and context-aware technologies boost a growing interest in the design, development, and deployment of vehicular networks for emerging applications. This leads to an increasing evolutionary tendency to change from vehicular networks toward cloud-assisted context-aware vehicular cyber-physical systems. In this article, we first propose a multi-layered context-aware architecture and introduce two crucial service components, vehicular social networks and context-aware vehicular security. Then we propose an application scenario regarding the context-aware dynamic parking services by illuminating the cloud-assisted ar…
Guest Editorial Introduction to the Special Issue on Dependable Wireless Vehicular Communications for Intelligent Transportation Systems (ITS)
2018
Over the past couple of decades, transportation systems have begun to receive widespread attention from the scientific community and emerged toward Intelligent Transportation Systems (ITS). Effective vehicular connectivity techniques can significantly enhance efficiency of travel, reduce traffic incidents and improve safety, and alleviate the impact of congestion; devising the ITS experience. Furthermore, during the past decades, the volume and density of vehicles increased significantly, especially the road traffic; this lead to a dramatic increase in the number of accidents and congestion, with negative impacts on the economy, environment, and quality of people’s lives. In particular, acc…
Measuring the weather’s impact on MAC layer over 2.4GHz outdoor radio links
2015
The weather s impact on the performance of a radio link at the 2.4 GHz ISM (Industry, Scientific and Medical) band had not been yet studied in great detail up to now as it is generally believed that the ultra-high frequency band is not significantly affected by weather conditions. However, our study shows significant correlations between meteorological variables and control frame errors at MAC (Medium Access Control) layer of the IEEE 802.11b/g standard. This study is performed over an outdoor radio link setting which has been monitored for several months. Moreover, we check if link distance and so modulation scheme and data rate are also decisive features of such impact. Our real scenario …