Editorial of the 2019 Workshop on Very Large Internet of Things (VLIoT)

We are proud of presenting the outcome of this third edition of the "Very Large Internet of Things" (VLIoT) workshop, which was held in Los Angeles (USA) in August 2019, in conjunction with the 45th International Conference on Very Large Data Bases (VLDB). Following the success path of the two previous workshop editions - in Munich (2017) and in Rio de Janeiro (2018) - VLIoT 2019 kept its tradition to be a vivid and high-quality technical forum for researchers and practitioners working with Internet of Things to share their experiences, visions and latest findings, most of them regarding the design, implementation, deployment and management of IoT systems at very large and scale. This editorial of the special issue introduces and introduces all papers presented at the workshop

Leveraging Application Development for the Internet of Mobile Things

So far, most of research and development for the Internet of Things has been focused at systems where the smart objects, WPAN beacons, sensors, and actuators are mainly stationary and associated with a fixed location (such as appliances in a home or office, an energy meter for a building), and are not capable of handling unrestricted/arbitrary forms of mobility. However, our current lifestyle and economy are increasingly mobile, as people, vehicles, and goods move independently in public and private areas (e.g., automated logistics, retail). Therefore, we are witnessing an increasing need to support Machine to Machine (M2M) communication, data collection, and processing and actuation control for mobile smart things, establishing what is called the Internet of Mobile Things (IoMT). Examples of mobile smart things that fit in the definition of IoMT include Unmanned Aerial Vehicles (UAVs), all sorts of human-crewed vehicles (e.g., cars, buses), and even people with wearable devices such as smart watches or fitness and health monitoring devices. Among these mobile IoT applications, there are several that only require occasional data probes from a mobile sensor, or need to control a smart device only in some specific conditions, or context, such as only when any user is in the ambient. While IoT systems still lack some general programming concepts and abstractions, this is even more so for IoMT. This paper discusses the definition and implementation of suitable programming concepts for mobile smart things - given several examples and scenarios of mobility-specific sensoring and actuation control, both regarding smart things individually, or in terms of collective smart things behaviors. We then show a proposal of programming constructs and language, and show how we will implement an IoMT application programming model, namely OBSACT, on the top of our current middleware ContextNet

Middleware Support for Generic Actuation in the Internet of Mobile Things

As the Internet of Things is expanding towards applications in almost any sector of our economy and daily life, so is the demand of employing and integrating devices with actuation capabilities, such as smart bulbs, HVAC,smart locks, industrial machines, robots or drones. Many middleware platforms have been developed in orderto support the development of distributed IoT applications and facilitate the sensors-to-cloud communication andedge processing capabilities, but surprisingly very little has been done to provide middleware-level, support andgeneric mechanisms for discovering the devices and their interfaces, and executing the actuation commands, i.e.transferring them to the device. In this paper, we present a generic support for actuation as an extension ofContextNet, our mobile-cloud middleware for IoMT. We describe the design of the distributed actuation supportand present a proof of working implementation that enables remote control of a Sphero mobile BB-8 toy

A middleware service for coordinated adaptation of communication services in groups of devices

Abstract—Recent research in pervasive computing has shown that context-awareness and dynamic adaptation are fundamental requirements of mobile distributed applications. However, most approaches that focus on context-aware dynamic adaptation use only the context information available at the mobile device to trigger a local adaptation. However, for distributed collaborative applications this is clearly insufficient, since a same adaptation has to be done, in synch, at all mobile devices of the group, and hence should also be based on a commonly agreed context. Therefore, for such kinds of applications one requires mechanisms and protocols to exchange the context information among the devices and to coordinate of the adaptation operations at a group of mobile device. In this paper we present a middleware service for coordinated adaptation of communication services in groups of devices. At each device this adaptation is achieved with minimal disruption for the application’s remote interactions. This middleware service is based on the notion of global context and a generic protocol for global context election and synchronization of the adaptation steps, which we called Moratus. Our middleware service was implemented using JGroups and evaluated for groups of up to 30 devices, showing acceptable latency for groups of such size. I

Practical Challenges And Pitfalls Of Bluetooth Mesh Data Collection Experiments With Esp-32 Microcontrollers

Testing network algorithms in physical environments using real hardware is an important step to reduce the gap between theory and practice in the field, and an interesting way to explore technologies such as Bluetooth Mesh. We implemented a Bluetooth Mesh data collection strategy and deployed it in indoor and outdoor settings, using ESP-32 microcontrollers. This data collection strategy also covers an alternative packet routing strategy based on Bluetooth Mesh - MAM - already discussed and simulated in previous work using the OMNET++ simulator. We compared the real-world ESP-32 experiments with the past simulations, and the results differed significantly: the simulations predicted a +459\% unique message collection compared to the results we obtained with the ESP-32. Based on those results, we also identified vast room for improvement in our ESP-32 implementation for future work, including solving an unexpected packet duplication in the MAM algorithm implementation. Even so, MAM performed better than Bluetooth Mesh's default relay strategy, with up to +4.06\% more (unique) data messages collected. We also discuss some challenges we experienced when implementing, deploying, and running benchmarks using Bluetooth Mesh and the ESP-32 platform.Comment: 12 pages, 6 figures and graph

Wireless Connectivity of a Ground-and-Air Sensor Network

This paper shows that, when considering outdoor scenarios and wireless communications using the IEEE 802.11 protocol with dipole antennas, the ground reflection is a significant propagation mechanism. This way, the Two-Ray model for this environment allows predicting, with some accuracy, the received signal power. This study is relevant for the application in the communication between overflying Unmanned Aerial Vehicles (UAVs) and ground sensors. In the proposed Wireless Sensor Network (WSN) scenario, the UAVs must receive information from the environment, which is collected by sensors positioned on the ground, and need to maintain connectivity between them and the base station, in order to maintain the quality of service, while moving through the environment.Comment: 8 pages, 11 figure

A Formal Framework for Modeling Context-Aware Behavior in Ubiquitous Computing

Abstract. A formal framework to contextualize ontologies, proposed i