Single-Layer versus Multilayer Preplanned Lightpath Restoration

Special Issue on ”Optical Networks” October 200

Elastic QoS Scheduling with Step-by-Step Propagation in IEEE 802.11e Networks with Multimedia Traffic

The spreading diffusion of wireless devices and the crowded coexistence of multimedia applications greedy of bandwidth and with strict requirements stress the service provisioning offered by wireless technologies. WiFi is a reference for wireless connectivity and it requires a continuous evolution of its mechanism in order to follow increasingly demanding service needs. In particular, despite the evolution of physical layer, some critical contexts, such as industrial networks, telemedicine, telerehabilitation, and virtual training, require further refined improvements in order to ensure the respect of strict real-time service requirements. In this paper an in-depth analysis of Dynamic TXOP HCCA (DTH) MAC enhanced centralized scheduler is illustrated and it is further refined introducing a new improvement, DTH with threshold. DTH and DTH with threshold can be integrated with preexisting centralized schedulers in order to improve their performances, without any overprovisioning that can negatively impact on the admission control feasibility test. Indeed, without modifying the centralized scheduler policy, they combine together the concepts of reclaiming transmission time and statistical estimation of the traffic profile in order to provide, at each polling, an instantaneous transmission time tailored to the variable traffic requirements, increasing, when necessary, the service data rate. These mechanisms can coexist with advanced physical layer-based solutions, providing the required service differentiation. Experimental results and theoretical analysis, based on elastic scheduler theory, show that they are effective especially in the case of Variable Bit Rate traffic streams in terms of transmission queues length, packets loss, delay, and throughput

Virtualized eNB Latency Limits

In flexible functional split, functions of a virtualized evolved NodeB (eNB) can be disaggregated in distributed computational resources. One of the main constraints for their placement is the latency experienced by the communication between the Virtual Machines (VM) hosting the functions. This paper evaluates experimentally the latency limits for different functional splits providing insights on flexible functional split implementationThis work has been partially funded by the EU H2020 5G-Transformer Project (grant no. 761536

On the Optimal Design of a Spectrum-Switched Optical Network With Multiple Modulation Formats and Rates

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Network Orchestration in Reliable 5G/NFV/SDN Infrastructures

In this paper, we elaborate an SDN orchestration solution aiming at the dynamic adaptation of service chain paths thereby addressing high-availability requirements of 5G applications. We present an SDN orchestrator that periodically monitors the availability of the network and, if necessary, promptly adapts service chain paths to recover from congestion events and to preserve network QoS performance of service data flows. A set of performance results are finally presented.This work has been partially supported by the EU H2020 5G Exchange (5GEx) innovation project (grant no. 671636) and by EU H2020 5G-Transformer Project (grant no. 761536

An implementation of EURORADIO protocol for ERTMS systems

European Rail Traffic Management System (ERTMS) is the European reference for interoperable and safer signaling systems to efficiently manage trains running. If implemented, it allows trains cross seamlessly intra-European national borders. ERTMS has defined a secure communication protocol, EURORADIO, based on open communication networks. Its RadioInfill function can improve the reaction of the signaling system to changes in line conditions, avoiding unnecessary braking: its advantages in terms of power saving and travel time has been analyzed. In this paper a software implementation of the EURORADIO protocol with RadioInfill for ERTMS Level 1 using GSM-R is illustrated as part of the SR-Secure Italian project. In this building-blocks architecture the EURORADIO layers communicates together through modular Application Programm Interfaces. Security coding rules and railway industry requirements specified by EN 50128 standard have been respected. The proposed implementation has successfully passed conformity tests and has been tested on a computer-based simulator

A Wireless System for Sport Assessment

In the context of sport assessment, the evaluation and monitoring of the referees decisions is of interest for several sports in order to avoid disputes and assist the referees in their activity. Some current solutions are based on video recording, third referee, etc. In this paper, a new wireless wearable system, result of the Italian research project REC-VISIO, is described suitable to assess the referees actions when they are on the move. The system is able to collect the referee staff visual perspective of a sport match, whose subjective is recorded, preprocessed and sent by a wireless network to a sideline workstation for final stabilization. The system architecture design and implementation are described along with the experimentation on the field, considering as use case a football match. The experimentation has shown the successful integration of all the different system components, where the cooperation of sensor-based subsystem, processing unit, and communication subsystem allows to collect and stabilize the video streaming reducing the effects of the movement of the referee, and send in real-time the video content to the sideline workstation without video quality degradation