Kassio Machado

A routing protocol based on energy and link quality for Internet of Things applications.

The Internet of Things (IoT) is attracting considerable attention from the universities, industries, citizens and governments for applications, such as healthcare, environmental monitoring and smart buildings. IoT enables network connectivity between smart devices at all times, everywhere, and about everything. In this context, Wireless Sensor Networks (WSNs) play an important role in increasing the ubiquity of networks with smart devices that are low-cost and easy to deploy. However, sensor nodes are restricted in terms of energy, processing and memory. Additionally, low-power radios are very sensitive to noise, interference and multipath distortions. In this context, this article proposes a routing protocol based on Routing by Energy and Link quality (REL) for IoT applications. To increase reliability and energy-efficiency, REL selects routes on the basis of a proposed end-to-end link quality estimator mechanism, residual energy and hop count. Furthermore, REL proposes an event-driven mechanism to provide load balancing and avoid the premature energy depletion of nodes/networks. Performance evaluations were carried out using simulation and testbed experiments to show the impact and benefits of REL in small and large-scale networks. The results show that REL increases the network lifetime and services availability, as well as the quality of service of IoT applications. It also provides an even distribution of scarce network resources and reduces the packet loss rate, compared with the performance of well-known protocols.

A Hierarchical Multi-hop Multimedia Routing Protocol for Wireless Multimedia Sensor Networks

Wireless Multimedia Sensor Networks (WMSNs) play an important role in pervasive and ubiquitous systems. WMSNs promise a wide scope of potential applications in both civilian and military areas, which require visual and audio information such as environmental monitoring, smart parking, traffic control, and other applications for smart cities. The multimedia content in such applications has the potential to enhance the level of collected information, show the real impact of the event and help to detect objects or intruders. However, WMSN applications must assure reliability, scalability, energy-efficiency and quality level (also from the user’s point-of-view) to support the transmission of multimedia content. With this goal in mind, this article outlines a smart Multi-hop hierarchical routing protocol for Efficient VIdeo communication over WMSN (MEVI). MEVI combines a cluster formation scheme with a minimal signaling overhead, a cross-layer solution to select routes based on network conditions and energy issues, and a smart scheme to trigger multimedia transmission according to sensed data. The cluster approach aims to minimize the energy consumption and is suitable for the distribution of multimedia content in WMSNs.

A smart multi-hop hierarchical routing protocol for efficient video communication over wireless multimedia sensor networks

For smart applications, nodes in wireless multimedia sensor networks (MWSNs) have to take decisions based on sensed scalar physical measurements. A routing protocol must provide the multimedia delivery with quality level support and be energy-efficient for large-scale networks. With this goal in mind, this paper proposes a smart Multi-hop hierarchical routing protocol for Efficient VIdeo communication (MEVI). MEVI combines an opportunistic scheme to create clusters, a cross-layer solution to select routes based on network conditions, and a smart solution to trigger multimedia transmission according to sensed data. Simulations were conducted to show the benefits of MEVI compared with the well-known Low-Energy Adaptive Clustering Hierarchy (LEACH) protocol. This paper includes an analysis of the signaling overhead, energy-efficiency, and video quality.

Recent Advances and Challenges in Wireless Multimedia Sensor Networks

Wireless Sensor Networks (WSNs) Akyildiz et al. (2002), Zhao & Guibas (2009) are formed of spatially distributed autonomous sensor nodes (motes). They are deployed in an environment where they can be used to monitor environmental conditions in collaboration, and communicate with each other through the wireless links. Several applications that are used in different areas have been outlined in the literature, such as, medical applications for monitoring patients Shnayder et al. (2005), monitoring mission critical environments, e.g., volcanic eruptions Werner-Allen et al. (2005), monitoring the structural integrity of buildings/towers Ceriotti et al. (2009) and several other multimedia applications.

Design of a routing protocol using remaining energy and link quality indicator (REL)

This paper sets out an extension of an AODV routing protocol, called Routing by Energy and Link quality indicator (REL). The proposed protocol adopts a new cross-layer approach as a mechanism to select the best routes. The paths are selected on the basis of remaining energy, a proposed link quality estimator (WeakLink), and hop count. Thus, REL provides reliability, energy-efficiency, and a fair distribution of network resources.

Urban Mobility Sensing Analysis through a Layered Sensing Approach

The increase of computing power and connectivity provide a favorable scenario to data collection never experienced before. The popularization of computing devices, specially portable and for personal use ones, and the large number of applications for these devices are factors that favor social interactions navigation, entertainment, and others. These applications occasionally evaluate the user context through sensors and their online activities, registering fragments of the user context recorded in semantically valuable datasets. In this study, we investigated the challenge of analysis of heterogeneous data from ubiquitous and pervasive applications using an approach based on layers of sensing. We evaluated the urban scenario considering the mobility of users and the weather. The results showed a phenomenon of behavior transition within a specific temperature range for a group of cities studied in this paper.

Pervasive forwarding mechanism for mobile social networks

Abstract In recent years, we have witnessed an increase in the popularity of mobile wireless devices and networks, with greater attention devoted to feasibility of opportunistic computing, sensing, and communication. In Mobile Social Networks (MSNs), communication is provided by spatial proximity and social links between peers, where personal devices carried by users communicate directly in a device-to-device mode. On one hand, human mobility provides encounters between peers and opportunities for communication without additional infrastructure; on the other hand, it introduces intermittent connections, network partitions, and long delay, requiring sophisticated message-forwarding mechanisms to improve network performance. Therefore, socially-inspired approaches which consider network structure and personal user features have been proposed to cope with these challenges. However, many studies disregard adaptive policies of message forwarding capable of dealing with variations of these features. In this paper, we investigated message dissemination in MSNs considering external factors such as temperature and seasonal calendar as environmental features capable of model users’preferences and encounters. We evaluated the time of day, the day of the week, and environmental variables such as weather and geographic position as important factors to the collective behavior and spatiotemporal characteristics of urban scenarios. This paper presents an analysis of real data from weather and human mobility, which depict distinct social interactions and spatial features characterized by changes in thermal conditions. Thus, we propose a socially-aware forwarding mechanism that is adaptable to the seasonality of personal preferences. Our experiments indicated that pervasive data can provide useful information towards the design of the next generation of human-centered Opportunistic Networks.

A Socially-Aware In-Network Caching Framework for the Next Generation of Wireless Networks

The modernization of urban scenarios includes improvements in wireless communication and efficient content dissemination to citizens. In these scenarios, the demographic densification and the phenomenon of popularization of mobile devices may characterize massive demands for online content in crowded regions, able to temporarily deplete the resources of the network infrastructure. To address this challenge, the next generation of wireless networks envision local cooperation among users using the D2D paradigm to improve content retrieval. Much effort has been dedicated to proposing mechanisms for cooperation and resource sharing; however, the advantages of big data have been little explored to support D2D to cope with urban and social dynamics. In this article, we investigate human mobility using data from online social networks, observing the mobility of 362,000 users during one year in New York City. We analyze the spatiotemporal features of the city, and their effects on encounters between users and content dissemination through D2D. Thus, we propose a framework for distributed caching based on social and spatiotemporal factors. The results of the experiments demonstrate the feasibility of D2D to offload the network demand and performance gain in the provision of content opportunistically.

Long-Term Spatiotemporal Analysis of Social Media for Device-to-Device Networks

The popularity of personal devices has been creating a new location-based content era, where users produce, share and access content anytime and anywhere. Mobile devices in the same area can cooperate to each other by using a Device-to-Device (D2D) communication and maximize the usage of network resources and allow the creation of new applications and experiences. In this paper, we investigate the dynamics of physical proximity of peers in a long-term study. We used one year of collected data from social media for an analysis of spatiotemporal features of how users encounter each other and the opportunities for content offloading in cellular networks. The results provided insights about the regularity of encounters, the role of routine and other spatial characteristics.