29 research outputs found
Fast Authentication in Heterogeneous Wireless Networks
The growing diffusion of wireless devices is leading to an increasing demand for mobility and security. At the same time, most applications can only tolerate short breaks in the data flow, so that it is a challenge to find out mobility and authentication methods able to cope with these constraints. This paper aims to propose an authentication scheme which significantly shortens the authentication latency and that can be deployed in a variety of wireless environments ranging from common Wireless LANs (WLANs) to satellite-based access networks
Analysis and Simulation of a Parallel Packet Switch for Satellite On-board Switching
In this paper we consider a packet switching system composed of X parallel switching planes
operating independently and at a speed lower than the input lines. Arriving traffic is segmented into
fixed length cells, then each cell is sent to one of the X planes, where it is switched to the correct
output port and finally recombined with the other cells, coming from other planes, to reconstruct the
original packet. This architecture, originally proposed by Iyer and McKeown [1], is referred to as a
Parallel Packet Switch (PPS) and allows to design a switching fabric operating at a fraction of the line
rate R. A PPS, with planes operating at rate r, must have at least k=R/r planes to avoid systematic
packet losses. In [1] it was proved that a PPS can emulate the behavior of an Output Queue Switch
(OQS) with the same buffering capabilities and the same number of ports. However, the centralized
scheduling algorithm required to achieve this result can not be easily implemented in hardware, due to
its complexity.
In this paper we propose a Redundant Parallel Packet Switch (RePPS), i.e. a PPS with more than k
planes, with a distributed scheduling algorithm, and multiplexing/demultiplexing stages without
coordination buffers, which is a fair trade-off between performance and complexity. In particular we
show that the minimum number n = X - k of redundant planes required to emulate an OQS with FIFO
policy under any incoming traffic type is n = k2-2k+1. The distributed scheduling algorithm, which is the
key component of the proposed switch, is presented and its performance, analyzed thru simulation, is
discussed for a realistic fabric with a limited number of redundant planes. The results so far obtained
suggest a possible application of this architecture for satellite on-board packet switches
SHORT TERM URBAN TRAFFIC FORECASTING USING DEEP LEARNING
Abstract. In today's world, the number of vehicles is increasing rapidly in developing countries and China and remains stable in all other countries, while road infrastructure mostly remains unchanged, causing congestion problems in many cities. Urban Traffic Control systems can be helpful in counteracting congestion if they receive accurate information on traffic flow. So far, these data are collected by sensors on roads, such as Inductive Loops, which are rather expensive to install and maintain. A less expensive approach could be to use a limited number of sensors combined with Artificial Intelligence to forecast the intensity of traffic at any point in a city. In this paper, we propose a simple yet accurate short-term urban traffic forecasting solution applying supervised window-based regression analysis using Deep Learning algorithm. Experimental results show that is it possible to forecast the intensity of traffic with good accuracy just monitoring its intensity in the last few minutes. The most significant result, in our opinion, is that the machine can generate accurate predictions even with no knowledge of the current time, the day of the week or the type of the day (holiday, weekday, etc).</p
Fast Authentication in Heterogeneous Wireless Networks
The growing diffusion of wireless devices is
leading to an increasing demand for mobility and security.
At the same time, most applications can only tolerate short
breaks in the data flow, so that it is a challenge to find out
mobility and authentication methods able to cope with these
constraints. This paper aims to propose an authentication
scheme which significantly shortens the authentication
latency and that can be deployed in a variety of wireless
environments ranging from common Wireless LANs
(WLANs) to satellite-based access networks
MOON: a New Overlay Network Architecture for Mobility and QoS Support
The continuously increasing diffusion of mobile devices
such as laptops, PDAs and smartphones, all equipped with
enhanced functionalities, has led to numerous studies about
mobility and to the definition of new network architectures
capable to support it.
Problems related to mobility have been addressed mostly
operating on the network or transport layers of the Internet
protocol stack. As a result, most of these solutions generally
require modifying the TCP and/or the IP protocol. Although this
approach is well suited to handle mobility, it lacks in
compatibility with the Internet Protocol Suite.
This consideration led us to study a fully TCP compatible and
flexible approach we dubbed MOON, for MObile Overlay
Network. This network architecture is currently under design at
LIPAR, the Internet, Protocols and Network Architecture Lab of
Politecnico di Torino
On the performance of web services, google cloud messaging and firebase cloud messaging
Smartphones and other connected devices rely on data services, such as Web Services (WS), Google Cloud Messaging (GCM) and Firebase Cloud Messaging (FCM), to share the information they collect or use. Traditionally, these services were classified according to the average number of bytes transmitted or their delivery time. However, when dealing with battery-operated devices, another important parameter to be taken into account is their power consumption. Furthermore, software designers and developers often do not consider the efficiency of a data communication system, but are simply concerned about ease-of-use and response time. In this paper, we compare FCM, GCM and two types of WS, namely Simple Object Access Protocol (SOAP) and REpresentational State Transfer (REST) WS in terms of delay, data efficiency, and power consumption. The final outcome is that RESTful WS outperforms all others, making GCM and FCM a viable alternative only when the amount of data to be transmitted is very limited, or when the mobile application requires the advanced services offered by FCM or GCM only. Keywords: Web Services, Google Cloud Messaging, Firebase Cloud Messaging, REST, SOA