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The availability of network softwarization and virtualization technology in the field of telecommunications has opened the door to a radical review of the applications, protocols, and deployment models. In this evolving framework, old assumptions and constraints specific to satellite communications must be carefully re-assessed. To this aim, we revisit the role of the performance enhancing proxy (PEP), replaced by a chain of custom virtual network functions properly enabled to optimize common web traffic performance over a backhaul dynamically enabled with a supplementary satellite link. The resulting virtual PEP (vPEP) is compliant with the breakthrough virtualization and slicing paradigms and can fruitfully exploit the advanced features of the most recent IETF technologies such as QUIC and MPTCP.

Serverless computing is an emerging proposition in the cloud offering landscape that promotes a higher level of abstraction, further decoupling software operations from the underlying hardware. Often recognized as an economically driven computational approach, the serverless model relies on the execution of short-lived stateless functions, enabling a fine-grained accounting and control of resources. In this context, function composition represents an appealing feature, allowing the composition of two or more functions to create tailored processing pipelines, incentivizingmodularityandreusabilityof functions, while paving the way to application-specific run-time optimizations. This work presents DIFFUSE: a DIstributed and decentralized platForm enabling Function composition in Serverless Environments. DIFFUSE embodies an innovative infrastructural support, enabling the efficient and transparent composition of functions by relying on pluggable middleware support, serving as a conveyor of messages among the platform components. Broadening the deployment spectrum of our proposal, we assess differentmiddleware solutions, each presenting distinct delivery profiles, evidencing the tradeoffs that emerge.

Industry 4.0 aims to revolutionize and digitize the manufacturing sector by enabling and facilitating interoperability, solution agility, flexible (re)configuration of production chain(s) while, at the same time, reducing costs by exploiting real time data. These capabilities require to link the plant floor with data flows from/to the enterprise borders and include as core enabling technologies the Internet of Things (IoT), cloud, and edge computing key to move and execute parts of the business logic. The new capabilities might be leveraged in an innovative way, especially in the plant floor to dynamically change the monitoring/control logic of the smart machinery. In our reference scenario, the data flows originating from the plant floor can be processed and filtered locally, creating the basis for a selective Quality of Service (QoS) mechanism allowing for the implementation of reactive services, such as predictive maintenance. To that end, we propose an innovative serverless edge processing solution used for monitoring geo-distributed industrial plants. The proposal is validated in realistic settings, under different operational regimes, exhibiting acceptable performance trends under realistic periodic and variable traffic scenarios.

We consider the scenario in which several TCP connections share the same access point (AP) and a congestion avoidance/control mechanism is adopted with the aim of assigning the available bandwidth to the clients with a certain fairness. When UDP traffic with real-time requirements is present, the problem becomes even more challenging. Very well-known congestion avoidance mechanisms are the Random Early Detection (RED) and the Explicit Congestion Notification (ECN). More recently, the Smart Access Point with Limited Advertised Window (SAP-LAW) has been proposed. Its main idea is that of computing the maximum TCP rate for each connection at the bottleneck, taking into account the UDP traffic to keep a low queue size combined with a reasonable bandwidth utilization. In this paper, we propose a new congestion control mechanism, namely, Smart-RED, inspired by SAP-LAW heuristic formula. We study its performance by using mean field models and compare the behaviours of ECN/RED, SAP-LAW, and Smart-RED under different scenarios. We show that while Smart-RED maintains some of the desirable properties of the SAP-LAW, it solves the problems it may have in case of bursty UDP traffic or TCP connections with very different needs of bandwidth.

Cloud computing has transformed the way IT services are provisioned and consumed, shifting the burden of configuration and management to the cloud provider. A lot of research has been conducted in the field aimed at optimizing and/or devise new in-cloud service delivery models. Yet, service outages are a norm rather than an exception. A natural evolution for application developers, especially for those applications that must meet high availability requirements, is to rely on resources and services provisioned by multiple cloud simultaneously. The so-called multi-cloud, distributed deployment model coupled with a monitoring solution spanning multiple domains could help in a timely identification and isolation of faulty components, alleviating service impairment issues. To this end, we propose an extension to NoMISHAP, a Platform as a Service (PaaS) multi-cloud middleware, introducing a cross layer monitoring solution for use in distributed cloud environments. Experimental results show the effectiveness of our approach and its ease of adoption for management tasks.

Wearable technology is no longer science fiction. Thanks to the growing capability in the production chain to miniaturize complex electronics, a wide variety of gadgets that can be worn or included in dresses and accessories have emerged. These smart gadgets can collect data about the physical condition of the user and/or the environment providing the basis for innovative and valuable services. The main goal of this paper is to assess this context through field experiments undertaken in a testbed comprised of sensing hardware deployed on open source boards such as Arduino. Moreover, coupled with the sensing tier, we propose a proof-of-concept deployment architecture enabling a wide range of wearable sensors to collect and transmit data to a logically centralized unit.

The actual advent of autonomous vehicles and the general improvement of traffic safety pass through quick and reliable message dissemination in a certain Area of Interest (AoI). Message dissemination among the vehicles composing an Internet of Vehicles (IoV) is of paramount importance and has to make use of fast and efficient multi-hop message forwarding to broadcast information. While most of existing works focus only on simple car platooning scenarios (e.g., a highway), we discuss here a fast multi-hop broadcast protocol able to quickly and reliably propagate an alert message even in general 2D (and 3D) topology scenarios.

The advent of broadband technology has revolutionized the fruition of multimedia contents. Moreover, the cloud is now moving the computational load from domestic devices to remote servers, enabling the provisioning of new multimedia services through the Internet. To provide a proper user experience, a low E2E latency and a high bandwidth are both required. Unfortunately, this is difficult to achieve in a shared network like the Internet. My PhD project focuses on the study and analysis of modern network protocols to identify viable solutions for a suitable user experience.

The technological evolution in the mobile sector has experienced an exponential growth in the last years. The number of functionalities has grown, and of course the way we use these devices has changed. Starting with calls and messages, introducing cameras, implementing Internet connectivity, and finally introducing the sensor technology, we arrive to today's smartphones. Following this trend, a popular application as gaming has extended its domain from home computers and consoles to the mobile realm. While there are many developers working on modern game genres, we devised a mobile game that join the rediscovery of ancient board games with the pleasure to play on a smart device. Through the development of the digital version of a game that was played centuries ago, we have created a very attractive tool able to raise the interest of children toward ancient history. We hence discuss here our attempt to digitally rediscover and enhance an ancient board game called "Fox and Geese"

Although much has been done in the field of accessibility, the World Wide Web is not yet for everyone. Many Internet users often find difficulties in navigating web pages. This is particularly true for people with visual impairments and blind people. In this paper, we present a review of the state of the art of the application of accessibility rules to web pages and describe which are the common problems that people with sight impairments must endure when surfing the Internet; to this aim, we use information collected during an interview with a blind user who is an expert in navigating the web using a screen reader.

In the recent years, ICT use in vehicular technology has expanded very fast. Inter-vehicle communication (IVC) is seen as the natural next step in this evolution whose availability will give rise to the next generation of smart vehicles. As this technology is deployed, a wide range of services varying from safety to entertainment will become factually accessible to passengers. Many of these envisaged services require a one-to-many communication model which demand for intelligent solutions able to propagate the message in areas of the network where it has not been heard before. To this end, we propose an enhancement of an existent optimal message propagation scheme proposed in the context of one dimensional vehicular networks, namely Fast-Broadcast. Our proposal generalizes the former with the objective of guiding message dissemination to an entire area of interest in generic road topologies. Our proposed scheme exploits bloom filter properties to further advance message propagation into the network. We contrast our approach with the original, lightweight state-of-the-art proposal, showing that it fulfills its design objectives.

We discuss MDTN: a delay tolerant application platform built on top of the Public Transportation System (PTS) and able to provide service access while exploiting opportunistic connectivity. Our solution adopts a carrier-based approach where buses act as data collectors for user requests requiring Internet access. Simulations based on real maps and PTS routes with state-of-the-art routing protocols demonstrate that MDTN represents a viable solution for elastic nonreal-time service delivery. Nevertheless, performance indexes of the considered routing policies show that there is no golden rule for optimal performance and a tailored routing strategy is required for each specific case.

Vehicular networks are receiving more and more attention from researchers and practitioners. In this context, it is particularly interesting to study realistic scenarios where vehicles are connected among themselves, or with other nodes. Think, for instance, of cooperating interconnecting objects forming an Internet of Vehicles (IoV) to collectively decide on maneuvers. Such connected autonomous vehicles would certainly require fast but also reliable group communications. Broadcast in wireless networks would be useful in this scenario if a tradeoff between reliable message delivery and low overhead can be solved. To this aim, we evaluate the performance of probabilistic flooding schemes and propose a heuristic-based solution that seems promising in fitting the IoV's needs.

It is easy to foresee a future with many smart and connected things, static or moving around, occupying space and creating an Internet of Things (IoT) with a 3D topology. Unfortunately, state-of-the-art routing protocols for ad-hoc networks have been designed to work in 2D scenarios. We here evaluate how these routing protocols would perform in a 3D IoT.

Scalable routing for ad-hoc wireless systems is a compelling and challenging task. In particular, due to mobility of nodes, topological information is volatile and changes in time. In this context, routing algorithms exploiting geographic information have been proposed to address this issue. This class of protocols exploits nodes' location, rather than their address and routing tables, to greedily route data towards a destination. Mainly proposed and tuned in the context of 2D MANETs these protocols exhibit less overhead in terms of control traffic and state, however, they are susceptible to local minina due to their localized decision making. In this context, we propose a hybrid position-topology based algorithm named Greedy Distance Vector (GDV), which tries to strike a balance between a greedy and topology-based forwarding process in a 3D environment. GDV greedily routes data packet toward a destination by exploiting nodes coordinates and whenever a local minima is found shifts to a topology, reactive-based approach to recover the delivery process. We present a preliminary simulation and discuss the benefits of the approach.

The worldwide diffusion of mobile technology has opened the door to a new era of distributed sensing. Indeed, mobile sensing and wireless technology can be exploited to create new information and services that have the potential to improve our lives in many ways. This becomes even more interesting if the benefits could reach the whole community, even people with disadvantages that are often left out by the digital divide. To this aim, we have developed a system able to offer an enhanced route navigation system, while at the same time gathering quality data through smartwatches. Even more interesting, we have endowed our system with an interaction paradigm based on vibration patterns so as to guide the user without the need for looking at the device. Our proposal avoids user distraction and field trials demonstrate its effectiveness when employed by visually impaired people.

Online social networks (OSN) have revolutionized many aspects of our daily lives and have become the predominant platform where content is consumed and produced. This trend coupled with recent advances in the field of Artificial Intelligence (AI) have paved the way to many interesting features, enriching user experience in these social platforms. Photo sharing and tagging is an important activity contributing to the social media data ecosystem. These data once labeled constitute a fruitful input for the system which is exploited to better the services of interest to the user. However, these labeling activity is imperfect and user subjective, hence prone to errors inherent to the process. In this paper, we present the design and the analysis of an Android app (namely GHio-Ca), an automatic photo tagging service relying on state-of-the-art image recognition APIs. The application is presented to the user as a camera app used to share pictures on social networks while relying on external services to automatically retrieve tags best representing the picture theme. Along with the system description we present a user evaluation involving 30 subjects.

FANETs are a promising solution for application scenarios involving UAVs. There are many mobility models that can be used to reproduce the behavior of the mobile nodes in an ad-hoc network, but some of these cannot simulate the realistic motion of UAVs. In this paper we list the available mobility models and try to understand which ones should be adopted for different FANET application scenarios, discussing their pros and cons.

The mobile revolution has brought us the possibility to enjoy our favorite applications anywhere and anytime. In this context, interactive games over mobile networks embody a fascinating case study both for their commercial success and for their technical challenges, thus, sparking interest and development. The current state of the art of interactive games over mobile networks is captured in this article. We discuss main requirements and analyze possible combinations of existing solutions to provide better support for highly interactive game sessions with mobile players. Copyright © 2012 John Wiley & Sons, Ltd.

This paper investigates one of the main game streaming services, the Steam In-Home Streaming, to analyze the generated network traffic. Gathered data can be used to model this type of traffic in simulations and to determine whether it could be supported by Internet connections around the world.

With vehicular networks quickly becoming the new wireless frontier of the Internet, car passengers embody the next consumers that will be targeted by multimedia content providers. However, researchers and practitioners are still struggling to tackle the technical challenges that raise in this scenario such as, for instance, the continuous variations in the number and type of flows served by the access points along the road. Considering different traveling scenarios in terms of vehicles' speed and location we discuss how access points could be improved to properly address these challenges, ensuring coexistence among heterogeneous types of flow, even in presence of moving vehicles that generate frequent network traffic variations.

The market penetration of in-home entertainment systems is playing a crucial role in the diffusion of interactive multimedia services. In this context, thin-client game systems have received a lot of attention, shifting the computational burden of the game play toward the server while the client renders a fat video stream. This paper proposes an analysis of the network characteristics of the Remote Play for PlayStation 4 and PlayStation Vita, providing some insights on the network dynamics of this system under different game types. The measurements involve video games of different genres, analyzing the bitrates, the packet size, capturing the dynamics of the whole streaming session. Results indicate that the service generates a large quantity of big packets downstream and smaller and lesser packets upstream. Gathered data can help to understand if this type of service could be offered through the today's normal Internet connections.

Cloud-based entertainment is becoming a hot topic for researchers and practitioners. In this context, thin client or cloud based gaming promise to attract users with the possibility to dematerialize the console and let the user play any possible game for any platform through the Internet. Basically, the computational burden is left to the cloud while the user enjoys a fat video feed accessed through her/his thin client via the shared wireless gateway. Unfortunately, this model of interaction also raises new complex technical issues that requires specific networking solutions. In this short paper we aim at addressing the heterogeneous flow coexistence problem at the home wireless gateway. We propose a solution based on a TCP Vegas-like congestion control algorithm deployed on top of the home gateway. Our solution works out of the box with the standard protocols at server, router and client level, thereby making deployment straightforward.

The popularity of digital games and the wide diffusion of mobile devices with sensors and communication capabilities have led many researchers to think how this technology can be put to good use to improve people’s lives and, in general, our society. In this short survey we present an overview on how mobile games can go beyond their entertainment purpose to pursue a service that may be useful to overcome health and accessibility impairments.

Peer-to-peer (P2P) overlay networks and mobile ad hoc networks share many key characteristics such as self-organization and decentralization; they also face the crucial challenge of providing connectivity in a decentralized, dynamic environment. However, when considering ad hoc networks composed of mobile devices such as smartphones, we cannot rely on the continuous end-to-end path between peers as for classic Internet P2P applications; rather, we have to deal with low node density that creates mobile-disconnected networks. Porting the P2P paradigm into mobile networks to create a mobile-to-mobile file sharing application will create a modern type of delay/disruption tolerant network. In this context, we discuss our new approach for P2P file sharing that considers networks composed of mobile smartphones. As an innovative feature, we leverage on peer mobility to reach data in other disconnected networks by implementing a delay/disruption tolerant network-like store-delegate-and-forward communication model, where a peer can delegate unaccomplished file download tasks to other peers. In order to increase the chances of eventually receiving the requested file while reducing the number of transmitted messages and data, social awareness is exploited by nodes to delegate unaccomplished tasks only to peers that are expected to be encountered again in the future. Copyright © 2011 John Wiley & Sons, Ltd.

Recent research has proposed swarming protocols as a possible approach to offload the Internet infrastructure when some content can be shared by several users. However, simulations have been generally used as experimental means. Instead, we present an application platform that allows a rapid development and testing of swarming protocols using off-the-shelf smartphones.

Mobile data traffic is becoming a key issue, causing traffic overload problems for classic resource providers. Tackling this issue, different solutions have been proposed, communed by the goal of alleviating the burden on the infrastructure while guaranteeing service availability. In this context, swarming protocols present the advantage of addressing the problem at its source, e.g., by engaging a lower number of direct connections with the network hosted server(s), while the requesters share these same resources among them. However, these solutions are generally verified only through simulation studies. While simulations consist in a necessary first step, they can be far from the actual outcome of employing real protocols and devices. To this end, we discuss BlueFall, an application platform that allows a rapid development and testing of swarming protocols using off-the-shelf smartphones and PCs. Pursuing our goal, we provide some evidence on two swarming schemes we have implemented in our testbed, profiling different access technologies.

The widespread adoption of mobile technology has opened the door to a new era for the public health sector. The ability to collect, share and access community health related data are key factors that have made mobile health an appealing addon to medicine practitioners and researchers. Mobile sensing and wireless communications can be exploited to create new information and services that could help prevent health risks, benefiting the community as a whole. As a proof of concept, we have developed an augmented reality application offering an enhanced pedestrian route navigation system, while at the same time gathering quality data through the devices. Thanks to this application we are able to enrich geographical maps on the web with historical data about brightness and noise levels, and to provide pedestrians with an improved navigation.

Mobile communication devices are expected to overtake traditional desktop PCs and become the dominant point of entry to the Internet. This technology shift has boosted user demand for multimedia applications and services which are now typically accessed through the wireless interface. Users expect to be always connected and able to run a variety of applications which sometimes impose contrasting requirements. Of particular research interest in this scenario is the coexistence between two popular categories of traffic: elastic and real-time, both of them covering a wide range of user applications. In this paper, we investigate the above issue in the scenario where service connectivity is provided through a multihop wireless network. To this end, we study two representative applications, one for each of the above categories, which are content download and interactive game play. We show by means of extensive simulations, how both the content download's goodput and the online game's per-packet delivery delay can be improved through an appropriate solution implemented on the wireless Internet Gateway.

Joining a private Wi-Fi network is an intricate operation for end users, especially when they must type a long and complicated password in order to gain access. Moreover, it is often the case where users connect to multiple such hotspots, placed in public places visited in their daily routine, further exacerbating the issue. In this paper we present WPA-Totem: a small device that emits Wi-Fi configuration tokens, which can be received by any NFC-enabled smartphones and tablets. Moreover, our proposal is able to automatically change the WPA passphrase after a specified period of time, keeping away the freeloaders from the network. WPA-Totem is aordable, easy to deploy and compatible with all the existing WPA2-Personal protected Wi-Fi networks. A new client can connect to the access point by simply tapping the totem and this, as we measured, leads to a dramatic improvement of the user experience.

In the era of the Internet of Everything, users with handheld or wearable devices equipped with sensing capability have become producers as well as consumers of information and services. The more powerful these devices get, the more likely it is that they will generate and share content locally, through ad hoc opportunistic connectivity, leading to the presence of distributed information sources and forwarders and the diminishing role of centralized, infrastructure-based servers. Despite this interesting portrait, the mobile and volatile nature of this network presents severe challenges demanding new networking techniques able to cope with the unpredictable and resource-constrained nature of mobile entities comprising it. In this context, we discuss novel data gathering and dissemination strategies in urban scenarios which do not rely on strict infrastructure mediation. While preserving the general aspects of our study and without loss of generality, we focus our attention toward practical applicative case studies which help us capture the characteristics of ad hoc opportunistic communication networks, and devise efficient solutions for use in real applicative contexts.

With the proliferation of connectivity enabled smartphones and the huge amount of data that everyday users generate through Web 2.0, the Internet is becoming bigger and bigger. The possibility to search for objects and users' profiles is at the base of the Internet of Everything paradigm. Surprisingly, the more we expand our interconnecting possibilities, the more we are interested in local, context-related information. In this paper we describe this envisioned scenario also discussing cutting edge technology that could soon turn this vision into reality.

Outdoor games are becoming an interesting opportunity thanks to the wide popularity of both games and mobile devices. In this paper, we consider the scenario where players are directly connected with each other, without relying on the infrastructure. To this end, we leverage on a hybrid architecture that allows client-server games to be played in adhoc mode. The energy consumption problem is addressed through the presence of background servers that alternate in acting as the game server. Realistic simulations on both ns-2 and ns-3 are exploited to evaluate this solution also providing a comparison of the two simulation frameworks.

Testing Vehicular Network protocols can be quite problematic. In fact, vehicular experiments are often expensive in both economic and temporal terms. As a consequence, researchers generally resort to software simulations which are a neccessary first step but still not sufficient. In this paper, we present two possible experimentation frameworks that could give a boost to the testing of protocols for vehicular networks: the first framework is based on Android smartphones, while the second is based on commodity laptop computers. In order to assess the feasibility and the performance of the proposed frameworks, we implemented through them a representative vehicle-to-vehicle multi-hop broadcast algorithm, i.e., the Fast Broadcast algorithm.

Nowadays, the proliferation of high-end mobile devices has enabled the possibility to create applications that pervasively cover our urban environment. However, the increasing demand for sharing and consuming information in this context requires new solutions able to sustain mobile-to-mobile communication. We envision a scenario where communication among mobile users is supported by opportunistic solutions, exploited to transfer data from a source user to a location. In this context, we propose a solution to geo-anchor data to a specific location through replication and bouncing among mobile users in the area. The rationale is that while users come and go, the data should remain anchored for a certain period of time or until the intended recipient(s) consume them. In this paper, we sketch our proposal and provide a preliminary analysis of its modus operandi.

Sensor-enabled smartphone's have become a mainstream platform for researchers due to their ability to collect and process large quantities of data, hence creating new opportunities for innovative applications. Yet, the limits in employing sensors to opportunistically detect human behaviors are not clear and deserve investigation. To this purpose, in this article, we discuss movement pattern recognition in day-by-day urban street behavior. As a case study, we restrict at recognizing situations when a pedestrian stops, crosses a street ruled by a traffic light; to do so we only use data coming from the accelerometer of the pedestrian's smartphone.

Sensor-enabled smartphone's are becoming a mainstream platform for researchers to collect data which could prove useful for discovering patterns in human behavior. Yet, employing sensorial data to extrapolate information is not clear and deserves investigation. In this article, we discuss movement pattern recognition in day-by-day urban street behavior. As a case study, we aim at recognizing when a pedestrian stops crosses a street ruled by a traffic light; to do so we only use data coming from the accelerometer of the pedestrian's smartphone.

Mobile phones have already evolved from simple voice communication means into a powerful device able to handle multimedia documents, personal productivity applications, and all sort of connections to the Internet. It is hence expected to see a popular application such as file sharing to become widely utilized even in this context. Indeed, the combination among mobile users and file sharing seems a match made in heaven: people could exchange files of interest just passing by each other. Moreover, new context related applications may be developed to exploit this possibility enriching our lives. In this work, we present design issues and implementation details about a real P2P file sharing application for mobile phones.