Carlo Giannelli

A Software Defined Networking architecture for the Internet-of-Things

The growing interest in the Internet of Things (IoT) has resulted in a number of wide-area deployments of IoT subnetworks, where multiple heterogeneous wireless communication solutions coexist: from multiple access technologies such as cellular, WiFi, ZigBee, and Bluetooth, to multi-hop ad-hoc and MANET routing protocols, they all must be effectively integrated to create a seamless communication platform. Managing these open, geographically distributed, and heterogeneous networking infrastructures, especially in dynamic environments, is a key technical challenge. In order to take full advantage of the many opportunities they provide, techniques to concurrently provision the different classes of IoT traffic across a common set of sensors and networking resources must be designed. In this paper, we will design a software-defined approach for the IoT environment to dynamically achieve differentiated quality levels to different IoT tasks in very heterogeneous wireless networking scenarios. For this, we extend the Multinetwork INformation Architecture (MINA), a reflective (self-observing and adapting via an embodied Observe-Analyze-Adapt loop) middleware with a layered IoT SDN controller. The developed IoT SDN controller originally i) incorporates and supports commands to differentiate flow scheduling over task-level, multi-hop, and heterogeneous ad-hoc paths and ii) exploits Network Calculus and Genetic Algorithms to optimize the usage of currently available IoT network opportunities. We have applied the extended MINA SDN prototype in the challenging IoT scenario of wide-scale integration of electric vehicles, electric charging sites, smart grid infrastructures, and a wide set of pilot users, as targeted by the Artemis Internet of Energy and Arrowhead projects. Preliminary simulation performance results indicate that our approach and the extended MINA system can support efficient exploitation of the IoT multinetwork capabilities.

Adaptive buffering-based on handoff prediction for wireless internet continuous services

New challenging deployment scenarios are accommodating portable devices with limited and heterogeneous capabilities that roam among wireless access localities during service provisioning. That calls for novel middlewares to support different forms of mobility and connectivity in wired-wireless integrated networks, to provide runtime service personalization based on client characteristics, preferences, and location, and to maintain service continuity notwithstanding temporary disconnections due to handoff. The paper focuses on how to predict client horizontal handoff between IEEE 802.11 cells in a portable way, only by exploiting RSSI monitoring and with no need of external global positioning, and exploits mobility prediction to preserve audio/video streaming continuity. In particular, handoff prediction permits to dynamically and proactively adapt the size of client-side buffers to avoid streaming interruptions with minimum usage of portable device memory. Experimental results show that our prediction-based adaptive buffering outperforms traditional static solutions by significantly reducing the buffer size required for streaming continuity and by imposing a very limited overhead.

Efficiently managing location information with privacy requirements in Wi-Fi networks: a middleware approach

The growing availability of wireless portable devices is leveraging the diffusion of location based services (LBSs) that provide service contents depending on the current position of clients, servers, and involved distributed resources. When a wide public of final users use LBSs, two primary issues are crucial: how to guarantee the proper level of user privacy given the need to disclose, to some extent, client location information; how to effectively manage the exchange of positioning information (and of its variations) notwithstanding the high heterogeneity of connectivity technologies and device hardware/software capabilities. The paper presents the privacy-related extension of our proxy-based mobile agent middleware to support personalized service provisioning to Wi-Fi portable devices, in particular, our middleware prototype adopts a two-level proxy-based architecture to provide LBSs with middleware-mediated effective access to location data, which are exposed at the proper level of granularity depending on privacy/efficiency requirements dynamically negotiated between clients and LBSs.

Evaluating Filtering Strategies for Decentralized Handover Prediction in the Wireless Internet

The rapid diffusion of heterogeneous forms of wireless connectivity is pushing the tremendous growth of the commercial interest in mobile services, i.e., distributed applications to portable wireless terminals that roam during service provisioning. In the case of both location-dependent mobile services and mobile services with session continuity requirements, there is a growing need for decentralized and lightweight solutions to predict cell handovers, in order to enable proactive service management operations that anticipate actual terminal reconnections at their newly visited cells. The paper discusses how to predict client handovers between IEEE 802.11 cells in a portable and completely decentralized way, only by exploiting RSSI monitoring and with no need of external global positioning systems. In particular, the paper focuses on proposing and comparing different filtering techniques for mitigating Received Signal Strength Indication abrupt fluctuations. Experimental results point out that i) filtering techniques can relevantly improve the efficiency and effectiveness of handover prediction, and ii) the choice of the most appropriate filtering solution to adopt should be made at provisioning time depending on specific service/system requirements, e.g., privileging minimum overhead vs. greater prediction proactivity.

Mobile proxies for proactive buffering in wireless Internet multimedia streaming

The widespread popularity of roaming wireless devices with limited and heterogeneous capabilities is enabling new challenging deployment scenarios for multimedia streaming in wired-wireless integrated networks. Streaming services should consider not only the support of different forms of mobility and connectivity, but also runtime service personalization based on client characteristics and location, while possibly maintaining streaming continuity independently of client roaming. The paper proposes an original middleware solution based on mobile proxies that work at the wired-wireless network edges, close to their limited wireless clients, to support their personalized access to continuous services, especially by pre-fetching multimedia contents to avoid streaming interruptions. In particular, the paper focuses on how to exploit handover prediction i) to migrate mobile proxies in advance to the wireless cells where mobile clients are going to reconnect, and ii) to proactively manage mobile proxy buffers, thus reducing memory and bandwidth usage. Experimental results show that our original lightweight solution for IEEE 802.11 cell handover prediction can significantly improve the management of proactive multimedia buffers, by respecting the challenging time constraints of the addressed application domain.

The real Ad-hoc Multi-hop Peer-to-peer (RAMP) middleware: An easy-to-use support for spontaneous networking

Spontaneous (or opportunistic) networks are multi-hop ad-hoc networks where nodes opportunistically exploit peer-to-peer contacts to share content and available resources in an impromptu way. Even if spontaneous networking has recently received growing interest, there is still the lack of impactful and wide-scale applications fully exploiting its potential. We claim that this is due to the intrinsic complexity of spontaneous network management, unsuitable to be directly handled by application developers. Therefore, this paper proposes a novel easy-to-use middleware, called RAMP, for the autonomic, cross-, and application-layer management of spontaneous networks. RAMP enables the dynamic sharing of all resources available via multiple, heterogeneous, intermittent, infrastructure-based, and ad-hoc links, which are orchestrated in a lightweight way to compose the multi-hop paths needed by sharing applications at runtime. The RAMP prototype is a useful tool for the community of researchers in the field and can be rapidly deployed over real execution environments. The reported experimental results demonstrate the feasibility of our approach and the limited RAMP overhead over common deployment scenarios.

A Unifying Perspective on Context-Aware Evaluation and Management of Heterogeneous Wireless Connectivity

The growing market of wireless devices with multiple connectivity technologies, e.g., Wi-Fi, Bluetooth, and UMTS, is pushing toward the necessity of seamless autonomic selection of the proper connectivity network at any time. That selection should be context-dependent and consider several elements, at different abstraction layers, from bandwidth requirements to network congestion, from connectivity costs to user preferences. As a symptom of the recognized relevance of this topic, relevant research work has recently addressed context-dependent connectivity management. We claim the need to provide both practitioners and newcomers of this research field with a comprehensive survey with a unifying perspective, to better point out similarities and specific aspects of the numerous solutions in the literature. In particular, the paper aims to achieve the twofold goal of i) identifying the primary design choices, together with corresponding tradeoffs, emerging from recent proposals, and ii) better positioning the wide variety of related work based on a single classification scheme. To that purpose, we introduce an original model to represent solution architectures, by showing how it makes the adopted design choices manifest and facilitates the positioning of proposed approaches, e.g., by throwing new light on the usage of 4th Generation and Always Best Connected terms. In addition, based on that model, we propose a novel taxonomy to cluster the proposals in the field along three first-level classification directions: management scope, evaluation process, and continuity management. A wide set of examples illustrate how our taxonomy is useful to thoroughly understand the differences and similarities among state-of-the-art solutions in the literature, to some extent independently on technology-specific implementation details, thus providing a valuable classification tool also for future proposals.

Mobility-aware management of internet connectivity in always best served wireless scenarios

The widespread availability of portable devices with multiple wireless interfaces, e.g., IEEE 802.11, WiMAX, Bluetooth, and/or UMTS, is leveraging the potential of novel supports to seamlessly and automatically select the proper connectivity technology to exploit at any time for any node and any running application. That selection should be context-dependent and take into account several aspects, at very different abstraction layers, from application-specific bandwidth requirements to expected client mobility, from user preferences to energy consumption. We claim the suitability of mobility-aware middlewares to relieve the application logic from the burden of determining the most suitable interface and connectivity provider for each client/application at service provisioning time. In particular, the paper motivates the need for novel context indicators, e.g., client/connector relative mobility, and describes effective lightweight solutions to estimate them flexibly, depending on dynamically introduced evaluation metrics. The paper presents primary architecture and implementation guidelines to build such a novel middleware solution. The proposed middleware has been experimentally validated and the reported performance results demonstrate the feasibility of the approach: it achieves accurate estimations of node mobility and consequently performs connection establishment/selection with very limited overhead.

Mobility Prediction for Mobile Agent-Based Service Continuity in the Wireless Internet

New challenging deployment scenarios are integrating mobile devices with limited and heterogeneous capabilities that roam among wireless access localities during service provisioning. This calls for novel middleware solutions not only to support different forms of mobility and connectivity in wired-wireless integrated networks, but also to perform personalized service reconfiguration/adaptation depending on client characteristics and in response to changes of wireless access locality. The paper proposes the adoption of Mobile Agent (MA) proxies working at the wired-wireless network edges to support the personalized access of limited wireless clients to their needed resources on the fixed network. In particular, the paper focuses on how to predict device mobility between IEEE 802.11 cells in a portable lightweight way, with no need of external global positioning systems. In fact, we claim that mobility prediction is crucial to maintain service continuity: MA-based proxies can migrate in advance to the wireless cells where mobile clients are going to reconnect to, in order to anticipate the local rearrangement of personalized sessions. The paper proposes and evaluates different mobility prediction solutions based on either client-side received signal strength or Ekahau positioning, all integrated in the SOMA platform. Both simulation and experimental results show that SOMA can predict the next visited cell with a very limited overhead and enough in advance to maintain service continuity for a large class of wireless Internet services.

Mobility-aware middleware for self-organizing heterogeneous networks with multihop multipath connectivity

The full exploitation of multihop multipath connectivity opportunities offered by heterogeneous wireless interfaces could allow innovative deployment scenarios where mobile nodes dynamically self-organize to best offer/exploit Internet connectivity. To seamlessly enable the potential of this scenario, we claim the suitability of novel mobility-aware and application-layer middleware that effectively considers a limited set of practical indicators for a coarse-grained dynamic estimation of expected reliability/quality of multihop paths. To validate the claim, we have developed an innovative middleware that manages the durability/ throughput-aware formation and selection of different multihop paths simultaneously, based on practical lightweight indicators of node mobility and wireless network characteristics. The reported results show the effective performance results of our middleware and, in general, the feasibility of application-layer middleware solutions with simplifying estimation assumptions to effectively make mobility-aware connectivity management decisions with limited overhead.