The fast increment in the number of IoT (Internet of Things) devices is accelerating the research on new solutions to make cloud services scalable. In this context, the novel concept of fog computing as well as the combined fog-to-cloud computing paradigm is becoming essential to decentralize the cloud, while bringing the services closer to the end-system. This paper surveys on the application layer communication protocols to fulfill the IoT communication requirements, and their potential for implementation in fog-and cloud-based IoT systems. To this end, the paper first briefly presents potential protocol candidates, including request-reply and publish-subscribe protocols. After that, the paper surveys these protocols based on their main characteristics, as well as the main performance issues, including latency, energy consumption and network throughput. These findings are thereafter used to place the protocols in each segment of the system (IoT, fog, cloud), and thus opens up the discussion on their choice, interoperability and wider system integration. The survey is expected to be useful to system architects and protocol designers when choosing the communication protocols in an integrated IoT-to-fog-to-cloud system architecture. Continuous innovations in hardware, software and connection solutions in the last decade have lead to the expansion of the Internet of Things (IoT) with the number of connected devices growing by the day [1] [2]. The huge amount of data generated by these devices require to find a proper system architecture able to both process and store all the data. While cloud-based architectures are being currently used for that purpose, the new fog computing paradigm is envisioned to scale and optimize the IoT infrastructures [3]. Examples of the cloud-based IoT solutions have been proposed in [4], [5], [6] and a detailed analysis of properties for IoT cloud providers has been conducted in [7]. These studies have shown that cloud computing has the potential to satisfy many IoT requirements, such as monitoring of services, powerful processing of sensor data streams and visualization tasks. On the other hand, fog-based solutions are suited to address real-time processing, fast data response, and latency issues, thus extending the cloud capabilities closer to the edge of the network [8]. Among many factors that will determine the performance in a combined IoT, fog and cloud computing paradigm, the application layer communication, which in turn depends on the selected communication protocols, is one of the main ones.Despite the popularity and wide spread usage of HTTP, the currently used protocols in various domains of IoT, fog and cloud domains are de-facto fragmented with many different solutions. This is due to the different requirements and areas that IoT needs to cover, combining the functionalities of sensors, actuators and computing power with security, connectivity and a myriad of other features. As a result, there is no common agreement on the reference architecture or adopted standards of co...

-The recent advances in the cloud services technology are fueling a plethora of information technology innovation, including networking, storage and computing. Today, various flavors have evolved of Internet of Things (IoT), cloud computing and the so-called fog computing, -a concept referred to capabilities of edge-devices and user's clients to compute, store and exchange data among each other and with the cloud. Though the evolution was not easily foreseeable to happen at such a rapid pace, each piece of it today facilitates and enables the deployment of what we commonly refer to as a smart scenario, including smart cities, smart transportation and smart homes. As most of the cloud, fog and network services today run simultaneously in each scenario, we observe that we are at the dawn of what maybe the next big step in the cloud computing and networking evolution, whereby services might be executed at the network edge, both in parallel and in a coordinated fashion, as well as supported by the unstoppable technology evolution. As edge devices become richer in functionality and smarter, -embedding capacities such as storage or processing, as well as embedding new functionalities, such as decision making, data collection and forwarding, sharing, etc, a real need is emerging for coordinated management of fog-to-cloud (F2C) computing systems. This paper introduces a layered fog-to-cloud (F2C) architecture, its benefits and strengths as well as the arising open and research challenges, making the case for the real need for their coordinated management. Our architecture, the illustrative use case presented and a comparative performance analysis, albeit conceptual, all clearly show the way forward towards a new IoT scenario with a set of existing and unforeseen services provided on a highly distributed and dynamic compute, storage and networking resources, bringing together heterogeneous and commodity edge devices, emerging fogs as well as conventional clouds. Keywords-Cloud computing, fog computing, fog-to-cloud, Internet of Things (IoT) I. INTRODUCTION: THE SCENARIOThe most recent developments in the information and communications technologies area have started to make a profound impact, through massive connectivity of humans and computers, as well as a massive proliferation of edge devices carried by humans (i.e., smart phones, and those associated with all the surroundings -the Internet of Things). These two major commodities not only have facilitated the true "anywhere, anyhow, anytime" users' connectivity, but also the data collection, further enabling the deployment of new value-added services. Today, the scenarios of smart cities, smart transportation and smart homes are no more domain of research of distant future, but are becoming the new "normal". Several references can be found in the literature that already showed the notable effect these concepts can bring to the business market [1]. For a rapid business and technological success to happen, however, two inherent features need to be addressed in t...

The recent technological advances related to computing, storage, cloud, networking and the unstoppable deployment of end-user devices, are all coining the so-called Internet of Things (IoT). IoT embraces a wide set of heterogeneous services in highly impacting societal sectors, such as Healthcare, Smart Transportation or Media\ud delivery, all of them posing a diverse set of requirements, including real time response, low latency, or high capacity. In order to properly address such diverse set of requirements, the combined use of Cloud and Fog computing turns up as an emerging trend. Indeed, Fog provides low delay for services demanding real time response, constrained to support low capacity queries, whereas Cloud provides high capacity at the cost of a higher latency. It is with no doubt that a\ud new strategy is required to ease the combined operation of cloud and fog infrastructures in IoT scenarios, also referred to as Combined Fog-Cloud (CFC), in terms of service execution performance metrics. To that end, in this paper, we introduce and formulate the QoS-aware service allocation problem for CFC architectures as an integer optimization problem, whose solution minimizes the latency experienced by the services while guaranteeing the fulfillment of the\ud capacity requirements.Peer ReviewedPostprint (published version

Animals play a profoundly important and intricate role in our lives today. Dogs have been human companions for thousands of years, but they now work closely with us to assist the disabled, and in combat and search and rescue situations. Farm animals are a critical part of the global food supply chain, and there is increasing consumer interest in organically fed and humanely raised livestock, and how it impacts our health and environmental footprint. Wild animals are threatened with extinction by human induced factors, and shrinking and compromised habitat. This review sets the goal to systematically survey the existing literature in smart computing and sensing technologies for domestic, farm and wild animal welfare. We use the notion of animal welfare in broad terms, to review the technologies for assessing whether animals are healthy, free of pain and suffering, and also positively stimulated in their environment. Also the notion of smart computing and sensing is used in broad terms, to refer to computing and sensing systems that are not isolated but interconnected with communication networks, and capable of remote data collection, processing, exchange and analysis. We review smart technologies for domestic animals, indoor and outdoor animal farming, as well as animals in the wild and zoos. The findings of this review are expected to motivate future research and contribute to data, information and communication management as well as policy for animal welfare.

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