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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.

Mobile Ad-Hoc Networks are currently experiencing a second youth in terms of research interest as well as providing benefits to our society. Clearly, this has been fostered by the wide range of applications that have become actually feasible thanks to the pervasive and increasing presence of smartphones, drones, sensors and other small devices with communication and sensing capability. Aiming to deploy solutions able to self-organize without the need for any infrastructure support, packet routing remains an open and critical research problem. Several routing solutions have been conceived to guarantee delivery and low overhead in this context. A promising approach, trying to limit the information needed and stored in the network, is represented by stateless solutions, a class of solutions not relying on topology state information. However, since they exploit local knowledge, the achieved performance in terms of packet delivery and latency is not always up to expectations. To this aim, we propose a dynamic routing protocol based on a tabu search approach, relying on local network knowledge and in-packet short-term memory to alleviate the local minima problem. A through experimental assessment is conducted, measuring protocol performance under different configurations and profiles, evidencing its benefits.

Industrial networked computing environments are expected to serve a wide range of applications with heterogeneous Quality-of-Service (QoS) requirements. This capability demands for novel, QoS-aware network management and configuration techniques resilient in the face of network changes. State-of-the-art approaches only focus on aspects related to the management of network devices. In this work, we move a step further, proposing an end-to-end QoS management approach in Time-Sensitive Networking (TSN) compliant networks, capable of handling reconfiguration events e.g., link-drop. Shedding some light on our proposal, we first discuss its functional building blocks, successively validating the approach on a real TSN testbed.

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.

Recent market trends in self-driving technology have revived the attention on vehicular networks, posing a demand for intelligent solutions supporting the proliferation of many useful applications. Inter-vehicular communication presents an opportunity, capable of providing the basis for localized, timely, collective intelligence. In this context, critical safety applications are particularly challenging, urging for quick multi-hop message propagation schemes within an area of interest. The anycast communication model embodied by safety applications and the shared broadcast medium demand for intelligent message propagation schemes minimizing latency. To this end, the state of the art approach is based on having different contention windows among vehicles so as to probabilistically select specific ones as forwarders in order to reduce the number of hops and transmissions needed to propagate the message. However, this solution has been mainly studied empirically. In this article, we present and discuss an analytical model, shedding light on the expected behavior and performance of such approach, along with a validation analysis conducted through the well known simulator NS-2.

We present the design and implementation aspects of a virtualized Performance Enhancing Proxy (vPEP), in a 5G compliant architecture involving the satellite as an alternate, additional backhaul link. The deployment of hybrid terrestrial-satellite configurations is realized through the vPEP agent, meant as a chain of Virtual Network Functions (VNFs), enhancing protocol performance and/or bringing value-added services in the end-to-end path. To this end, we discuss a possible integration approach of the satellite link into the 5G service-based architecture, outlining key functional components. In addition, we present a preliminary evaluation study employing a vPEP embodying the QUIC protocol in a possible web-browsing, 5G optimized slice.

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.

In this paper, we propose GeoSaW, a delay-tolerant routing protocol for Airborne Networks in Search and Rescue scenarios. The protocol exploits the geographical information of UAVs to make appropriate message forwarding decisions. More precisely, the information about the future UAV&rsquo, s motion path is exploited to select the best UAV carrying the message towards the destination. Simulation results show that the proposed solution outperforms the classic DTN routing protocols in terms of several performance metrics.

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.

Unmanned aerial vehicles (UAV), or commonly referred to as Drones, have captured our imagination bringing new and challenging service provisioning schemes into the networking scenario. We might indeed be reaching the day where communication-enabled drones might be employed in synergy with deployed public networks offering alternate service access means. In this context, we contribute with quantitative analysis of classic routing algorithms in a 3D mobile environment, shedding some light on their performance tradeoffs.

In recent years we have seen a great proliferation of smart vehicles, ranging from cars to little drones (both terrestrial and aerial), all endowed with sensors and communication capabilities. It is hence easy to foresee a future with even more smart and connected vehicles moving around, occupying space and creating an Internet of Vehicles (IoV). In this IoV, a multitude of nodes (both static and mobile) will generate a continuous multihop flow of local information to support local smart environment applications. Therefore, one interesting environment for the IoV would be in the form of 3-D mobile ad-hoc networks (MANETs). Unfortunately, MANET routing protocols have generally been designed and analyzed keeping in mind a 2-D scenario; there is no guarantee on how they would support a 3-D topology of the IoV. To this end, we have considered routing protocols deemed as the state-of-the-art for classic MANETs and tested them over 3-D topologies to evaluate their assets and technical challenges.

[EN] Flying ad-hoc networks are becoming a promising solution for different application scenarios involving unmanned aerial vehicles, like urban surveillance or search and rescue missions. However, such networks present various and very specific communication issues. As a consequence, there are several research studies focused on analyzing their performance via simulation. Correctly modeling mobility is crucial in this context and although many mobility models are already available to reproduce the behavior of mobile nodes in an ad-hoc network, most of these models cannot be used to reliably simulate the motion of unmanned aerial vehicles. In this article, we list the existing mobility models and provide guidance to understand whether they could be actually adopted depending on the specific flying ad-hoc network application scenarios, while discussing their advantages and disadvantages.

Mobile networks are expected to serve a wide range of verticals, however the Long Term Evolution (LTE) network is optimized for basic mobile operator services only. The network functions serving LTE networks are largely implemented as dedicated single function devices that offer poor customization options. This intrinsic inflexibility makes current LTE networks unable to meet the requirements of future mobile networks. For example, LTE networks experience signaling storms because the signals exchanged by the network functions cannot be optimized according to the current usage pattern of mobile services. Modularizing these network functions would enable a refactoring of the LTE network, allowing operators to compose networks that adapt and evolve with the influx of verticals. In this article, we present a new approach for refactoring the network functions serving LTE networks which can be leveraged to compose a modular mobile network optimized for the verticals using its services. As an example, we demonstrate that deploying network functions at the edge significantly reduces the signals exchanged within a mobile network.

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.

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.

Active Queue Management (AQM) techniques have been proposed to support scenarios with many connections sharing the same bottleneck. The basic idea is that a smart management of the bottleneck queue can avoid the saturation of the link and ensure a smoother use of the available bandwidth. This is generally achieved by exploiting the flux control mechanism of TCP and its behavior in case of packet losses or other explicit notifications. In this paper we consider classic and innovative AQM techniques and analyse their performance under different scenarios through the use of mean field models.

Internetworking often requires a large amount of users to share a common gateway to obtain connectivity to the Internet. Congestion avoidance mechanisms are used to prevent the saturation of the gateway which represents a bottleneck of the system. The most popular congestion avoidance mechanisms are the Explicit Congestion Notification (ECN) and the Random Early Detection (RED). Recently, a new method for the congestion avoidance has been proposed: the Smart Access Point with Limited Advertised Window (SAP-LAW). The main idea is to hijack the acknowledge packets in the TCP connections in order to artificially reduce the advertised destination window according to some bandwidth allocation policy. Therefore, the flux control mechanism is artificially exploited to control the congestion at the bottleneck. The advantage of this approach is that it does not require any modification in the TCP implementations at the clients. In this paper, we propose stochastic models for the ECN/RED and SAP-LAW mechanisms in order to compare their performances under different scenarios. The models are studied in mean field regime, i.e., under a great number of TCP connections and UDP based transmissions. Augmenting previous work on ECN/RED, we consider the presence of UDP traffic with bursts, and short lived TCP connections. The models for SAP-LAW are totally new. The comparison is performed in terms of different performance indices including average queue length, system throughput and expected queuing time.

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.

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.

Cloud-based entertainment is gaining momentum. With the cost of commodity hardware lowering by the day and the consumer market penetration of in-house digital entertainment systems, a new generation of interactive services has come into being. This new technological wave has launched new content producers and providers that are rapidly adapting to match the consumer demand. In this context, thin client or cloud-based gaming is attracting much attention, shifting the computational burden to the cloud while the consumer enjoys a fat video feed accessed through its thin client via the shared wireless gateway. However, this model of interaction raises new challenges that demand for specific networking solutions aimed at addressing the heterogeneous flow coexistence problem at the home wireless gateway. We propose a solution to this problem by devising a Transmission Control Protocol Vegas-like congestion control algorithm deployed on top of the home gateway. Our solution works out of the box with the standard protocols at the server, router, and client levels, thereby making deployment straightforward. Experimental assessment with real traffic traces shows that our solution addresses the problem effectively.

Computer-centered services and broadband wireless connectivity have boosted the demand for delivery of multimedia-based entertainment from the Internet to in-house wireless appliances. In this context, rich-media applications can be supported by a variety of protocols, each sharing the same bottleneck, affecting one another's performance. Indeed, in current systems, real-time applications (e.g., video streaming, online games) suffer from delays caused by the interference of elastic, best-effort (e.g., TCP-based download sessions) traffic. In this paper we propose a solution to this problem, addressed by deploying a Vegas-like congestion control algorithm at the home gateway, requiring no client-side modification.

In recent years, the number of appliances connected to the Interned has steadily increased thanks to the wide popularity of WIFI/3G enabled mobile devices. This has led to an increase of multimedia resource consumption, causing traffic overload problems for classic resource providers. Different solutions have been studied to shift this traffic overhead from the server(s) towards the client(s) through the employment of the so called swarming protocols. However, most of these solutions have been verified only through simulations. 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, in this paper we describe BlueFall, an application that could allow to test swarming protocols using actual mobile phones. Pursuing our goal, we provide some preliminary evidence on two simple swarming schemes we have implemented in our testbed.

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.

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.

Opportunistic Networking (ON) is an emerging networking paradigm exploiting contact opportunities and node mobility to move data between nodes. Differently from infrastructure networks, where conventional information like network topology could be used to route messages, ON demands for new techniques able to cope with a dynamic evolving network topology and scenarios with limited or no information. Further, the heterogeneity of the autonomous actors involved in the network processes translates into different network protocol constraints which, if not considered carefully could lead to scalability problems of the devised solutions. In this context, in this article, we provide a survey of relevant opportunistic solutions and their motivation, with emphasis on the data gathering and dissemination processes. Despite the major research effort, it emerges there is no one silver bullet.

When discussing vehicular networking we have also to consider the multitude of commuters daily travelling to work through public transportation means such as buses, metros, and trains. Indeed, through their smartphones, commuters can generate communication traffic while moving, thus embodying a significant part of an urban communication scenario. In this context, we discuss in this article a way to port the P2P paradigm into mobile disconnected networks composed by commuters’ smartphones. Different from classical P2P file-sharing systems, our solution is designed to specifically leverage on the mobility pattern of commuters. In essence, users can exchange multimedia contents when in proximity with each other; they can also leverage on peer mobility and encounters in order to extend a requesting peer reacharea to other local disconnected networks. This is achieved by implementing a DTN-like store-delegate-and-forward communication model over underlying social networks where a peer can delegate unaccomplished file download tasks to frequently encountered peers: e.g., other commuters sharing a part of the path between home and workplace. We show how involving only frequently encountered peers/commuters improves the success ratio for the file search task while reducing useless communication overhead.

Mobile Ad-hoc Networks (MANETs) exhibit unpredictable topology with heterogeneous node contact rates, high mobility and limited information. When dealing with such challenging environments, the mobility model has a key role in testing the performance and proving the expected behavior of routing algorithms. While synthetic mobility models have been largely used to measure quantitative aspects of routing protocols, they are not sufficient as they do not capture reliably the properties of movement in the real life scenarios. In this paper we present some experimentation done in THE_ONE simulation environment, involving our M2MShare, a peer-to-peer (P2P) delay tolerant file sharing platform for mobile networks. For testing purposes we have chosen the Working Day Movement (WDM) model which is shown to make a good approximation of human mobility patterns and provides the flexibility of configuring real life test scenarios.

Due to mobility, communication links between mobile nodes are transient and network maintenance overhead is a major performance bottleneck for data transmission. Low node density makes it difficult to establish end-to-end connection, thus impeding a continuous end-to-end path between a source and a destination. This creates a modern type of DTN, which was originally intended for communication in outer space, but is now directly accessible from our pockets. In this paper, we present a special purpose system for searching and transferring files tailored to both the characteristics of MANETs and the requirements of P2P file sharing. Our approach is based on an application layer overlay network. We port a DTN type solution into an infrastructure-less environment like MANETs and leverage peer mobility to reach data in other disconnected networks. This is done by implementing an asynchronous communication model, store-delegate-and-forward, like DTNs, where a peer can delegate unaccomplished file download or query tasks to special peers. To improve data transmission performance while reducing communication overhead, we select these special peers by the expectation of encountering them again in future and assign them different download starting point on the file.