Gianluca Reali

Autonomic control and personalization of a wireless access network

As ICT services are becoming more ubiquitous and mobile and access technologies grow to be more heterogeneous and complex, we are witnessing the increasing importance of two related needs: (i) users need to be able to configure and personalize their services with minimal effort; (ii) operators desire to engineer and manage their networks easily and efficiently, limiting human agency as far as possible. We propose a possible solution to reach these goals. Our vision, developed in the so-called Simplicity project, is based on a personalization device, which, together with a brokerage framework, offers transparent service configuration and runtime adaptation, according to user preferences and computing/networking context conditions. The capabilities of this framework can be exploited: (i) on the user side, to personalize services, to improve the portability of services over heterogeneous terminals and devices, to adapt services to available networking and terminal technologies; (ii) on the network side, to give operators more powerful tools to define new solutions for distributed, technology-independent, self-organizing, autonomic networking systems. Such systems could be designed so as to be able to react autonomously to changing contexts and environments. In this paper, we first describe the main aspects of the Simplicity solution. We then want to show that our approach is indeed viable. To prove this point, we present an application which exploits the capabilities of the Simplicity system: a mechanism to drive mobile users towards the most appropriate point of access to the network, taking into account both user preferences and network context. We use simulation to evaluate the performance of this procedure in a specific case study, where the aim is to balance the load in an 802.11b access network scenario. The numerical results show the effectiveness of the proposed procedure when compared to a legacy scenario and to another solution from literature. To give ample proof of the feasibility of our solution, we also designed and implemented a real prototype. The prototype enables not only the load to be balanced among different 802.11 access points, but also network and application services to be differentiated as a function of user profiles and network load. The main aspects of this prototype are presented in this paper.

On ant routing algorithms in ad hoc networks with critical connectivity

This paper shows a novel self-organizing approach for routing datagrams in ad hoc networks, called Distributed Ant Routing (DAR). This approach belongs to the class of routing algorithms inspired by the behavior of the ant colonies in locating and storing food. The effectiveness of the heuristic algorithm is supported by mathematical proofs and demonstrated by a comparison with the well-known Ad hoc On Demand Distance Vector (AODV) algorithm. The differences and the similarities of the two algorithms have been highlighted. Results obtained by a theoretical analysis and a simulation campaign show that DAR allows obtaining some important advantages that makes it a valuable candidate to operate in ad hoc networks and the same method helps in the selection of the algorithm parameters. Since the approach aims at minimizing complexity in the nodes at the expenses of the optimality of the solution, it results to be particularly suitable in environments where fast communication establishment and minimum signalling overhead are requested. These requirements are typical of ad hoc networks with critical connectivity, as described in the paper. Thus the performance of the proposed algorithm are shown in ad hoc networks with critical connectivity and compared to some existing ad hoc routing algorithms.

A simulation tool for nanoscale biological networks

a b s t r a c t Nanonetworking is a new interdisciplinary research area including nanotechnology, biotechnology, and ICT. In this paper, we present a novel simulation platform designed for modeling information exchange at nanoscales. This platform is adaptable to any kind of nano bearer, i.e. any mechanism used to transport information, such as electromagnetic waves or calcium ions. Moreover, it includes a set of configuration functions in order to adapt to different types of biological environments. In this paper, we provide a throughout description of the simulation libraries. In addition, we demonstrate their capabilities by modeling a section of a lymph node and the information transfer within it, which happens between antibody molecules produced by the immune system during the humoral immune response.

TCP-Like Molecular Communications

In this paper, we present a communication protocol between a pair of biological nanomachines, i.e., a transmitter and a receiver, built upon molecular communications in an aqueous environment. In our proposal, the receiver, acting as a control node, sends a connection setup signal to the transmitter, which stokes molecules, to start molecule transmission. The molecules transmitted by the transmitter propagate in the environment and are absorbed by the receiver through its receptors. When the receiver absorbs the desired quantity of molecules, it releases a tear-down signal to notify the transmitter to stop the transmission. The proposed protocol implements a bidirectional communication by using a number of techniques originally designed for the TCP. In fact, the proposed protocol is connection-oriented and uses the TCP-like probing to find a suitable transmission rate between the transmitter and the receiver to avoid receiver congestion. Unlike the TCP, however, explicit acknowledgments are not used since they would degrade the communication throughput due to the large delay, which is a characteristic feature of molecular communications. Thus, the proposed protocol uses implicit acknowledgments, and feedback signals are sent by the receiver to throttle the transmission rate at the transmitter, i.e., explicit negative feedback. We also present the results of an extensive simulation campaign, used to validate the proposed protocol and to properly dimension the main protocol parameters.

Comparison of two lightweight protocols for smartphone-based sensing

Smartphones are equipped with numerous sensors and have become sophisticated sensing platforms. However, several sensing applications running on a smartphone can degrade the device performance. This can be overcome by using lightweight application protocols which improve the smartphone performance in terms of bandwidth consumption, battery lifetime and communication latency. This work focuses on two emerging application protocols: the Message Queuing Telemetry Transport (MQTT) and the Constrained Application Protocol (CoAP). Although both protocols have been designed for highly constrained environments such as sensors, they are also appropriate to be adopted in smartphone applications. We provide a qualitative and quantitative comparison between MQTT and CoAP when used as smartphone application protocols and we give preliminary indications on the application scenarios in which either protocol should be adopted. While MQTT has already been adopted in smartphone applications, CoAP is relatively new and has up to now mainly been considered for sensors and actuators. Our comparison shows that CoAP can be a valid alternative to MQTT for certain application scenarios.

An enabling platform for autonomic management of the future internet

This article shows an autonomic management solution based on the recently defined programmable node architecture NetServ. The article starts with a general description of the classical network management requirements and their adaptation to the expected network evolution. After a description of the major issues characterizing the management of the expected Future Internet, the main autonomic management paradigms, and some recently introduced autonomic service platforms, we show and demonstrate the effectiveness of the NetServ architecture. Born as a means to deploy and execute networked services at runtime over programmable routers, NetServ has proved to be a suitable environment for hosting an autonomic management architecture.

Simulation of molecular signaling in blood vessels: Software design and application to atherogenesis

Abstract This paper presents a software platform, named BiNS2, able to simulate diffusion-based molecular communications with drift inside blood vessels. The contribution of the paper is twofold. First a detailed description of the simulator is given, under the software engineering point of view, by highlighting the innovations and optimizations introduced. Their introduction into the previous version of the BiNS simulator was needed to provide the functions for simulating molecular signaling and communication potentials inside bounded spaces. The second contribution consists of the analysis, carried out by using BiNS2, of a specific communication process happening inside blood vessels, the atherogenesis, which is the initial phase of the formation of atherosclerotic plaques, due to the abnormal signaling between platelets and endothelium. From a communication point of view, platelets act as mobile transmitters, endothelial cells are fixed receivers, sticky to the vessel walls, and the transmitted signal is made of bursts of molecules emitted by platelets. The simulator allows for the evaluation of the channel latency and the footprint on the vessel wall of the transmitted signal as a function of the transmitter distance from the vessels wall, the signal strength, and the receiver sensitivity.

Applications of molecular communications to medicine: A survey

In recent years, progresses in nanotechnology have established the foundations for implementing nanomachines capable of carrying out simple but significant tasks. Under this stimulus, researchers have been proposing various solutions for realizing nanoscale communications, considering both electromagnetic and biological communications. Their aim is to extend the capabilities of nanodevices, so as to enable the execution of more complex tasks by means of mutual coordination, achievable through communications. However, although most of these proposals show how devices can communicate at the nanoscales, they leave in the background specific applications of these new technologies. Thus, this paper shows an overview of the actual and potential applications that can rely on a specific class of such communications techniques, commonly referred to as molecular communications. In particular, we focus on health-related applications. This decision is due to the rapidly increasing interests of research communities and companies to minimally invasive, biocompatible, and targeted health-care solutions. Molecular communication techniques have actually the potentials of becoming the main technology for implementing advanced medical solution. Hence, in this paper we provide a taxonomy of potential applications, illustrate them in some details, along with the existing open challenges for them to be actually deployed, and draw future perspectives.

Modeling CD40-based molecular communications in blood vessels.

This paper presents a mathematical characterization of the main features of the molecular communication between platelets and endothelial cells via CD40 signaling during the initial phases of atherosclerosis, known also as atherogenesis. We demonstrate through laboratory experimentation that the release of soluble CD40L molecules from platelets in a fluid medium is enough to trigger expression of adhesion molecules on endothelial cells surface; that is, physical contact between the platelets and the endothelial cells is not necessary. We also propose the mathematical model of this communication, and we quantify the model parameters by matching the experiment results to the model. In addition, this mathematical model of platelet-endothelium interaction, along with propagation models typical of blood vessels, is incorporated into a simulation platform. Analysis of the simulation results indicates that these enhancements render the simulator a useful tool upon which to base discussion for planning research, and has the potential to be an important step in the understanding, diagnosis, and treatment of cardiovascular diseases.

On the Performance of Service Publishing in IEEE 802.11 Multi-Access Environment

In a multi-access/service IEEE 802.11 environment, the problem of providing users with service-related information to support a correct and fast network selection is expected to become a very important issue. We present a quantitative comparison between the legacy scenario, where each user must enter a network point of access to check its service offer, and the enhanced scenario where some service-related information is broadcasted through beacons. Results confirm the effectiveness of the beacon-based approach, in terms of discovery time, server load, and bandwidth consumption