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Traffic engineering is a critical issue that has to be addressed in metro Ethernet networks for proper and efficient resource utilization as well as facilitating quality of service. This article aims at understanding the relevant issues and outlines novel algorithms for multipoint-TE in the metro Ethernet. We first propose a grouping scheme that extends the current label space in the provider domain and allows for a large number of VLANs to be provisioned efficiently. Next, the issues of load balancing, multiple spanning trees, and interaction between grouping and bandwidth provisioning are discussed, and solutions are provided. Finally, we address differentiated survivability in next-generation Ethernet and provide a novel scheme based on multiple spanning trees. The schemes proposed in this article are shown to be scalable, bandwidth-efficient, and practical for both the customer and the provider.

The ceramic ball grid array (CBGA) packages are typically used for high I/O count area array assemblies. As the package size is large, the distance to neutral point is also high resulting in a large thermal deformation mismatch between the CBGA package and the printed circuit board (PCB). In order to cope with this problem, a special solder joint connection is used. As CBGA assemblies are used for high pin count assemblies, a full 3D thermo-mechanical modelling of an assembly to an FR4 board is not possible anymore. Therefore, a modified micro–macro methodology is proposed where only the critical solder joint is modelled in detail, while the other connections are replaced by equivalent connections. For several CBGA configurations, simulation results are correlated to thermal cycling test results. Finally, a parameter sensitivity study shows that the PCB properties have a significant influence on the solder joint reliability.

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In this paper, we investigate the problem of spectrum sharing where a macro base station (MBS) is underlaid with multiple femto base stations (FBSs). This problem is investigated from a game theoretic perspective where two games are herein investigated. First, in the non-cooperative case, the MBS and FBSs (i.e., players) behave selfishly aiming at improving their respective payoffs (achievable rate), whereas in the second case a hierarchy is introduced among players as a means to improve the overall network efficiency. This problem is cast as a hierarchical game with a leader-follower approach in which the MBS is designated as the leader whereas FBSs are the followers. Furthermore, in the case of incomplete game information, a learning mechanism based on information exchange among players is investigated in which the leader builds its own estimate of other players's strategies and strategically adapt its decisions to maximize its expected utility. Numerical results corroborate the fact that the hierarchical model outperforms the non-cooperative approach in terms of achievable rate and optimal number of deployed small cells (or femtocells) in the network. Additionally, learning mechanisms based on public information exchange are shown to outperform the private information case as well as the selfish/myopic case.

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The concept of transmission network availability is discussed and defined. On this basis, a method for measuring the transmission network availability is presented, along with its applications and usefulness to some networks. The presence of privileged customers into the network enable us to compare preemptive vs. non-preemptive mechanisms of using network redundancies. The effects of the mechanisms on network availability are discussed and compared.

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[Abstract] This paper presents the Alcatel Alenia S pace ‐ Italy (AAS-I) product: Secure End-To-End Telemetry, Tracking and Commanding System for Military Satellites. The “product” is the design of a Secure TT&C System composed of the most advanced units and technologies tested successfully in existing Progra ms and considered as homogenous group. This complete system has been designed for obtain t he most warrantee of security, effectiveness and performances in the Satellite tec hnology.

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The paper deals with results from the experimental characterization of the Double-Stage Hall-effect Thruster prototype developed, under the European Space Agency sponsorship, by AASI, as prime contractor and ALTA, as AASI sub-contractor. The thruster architecture implements an intermediate electrode along the discharge chamber, designed to be an additional electrons source other than the external cathode, and a magnetic circuit providing a radial magnetic field profile with two different peaks, the most internal one conceived for generating an Hall-effect ionisation mechanism. Although experimental results show interesting performance, especially in terms of thrust efficiency, in the range of 50% for most of the investigated conditions, thruster has not been able to operate in a real DoubleStage configuration for the inability of the intermediate electrode of emitting a sufficient amount of electrons for propellant ionisation, independent on cathode electrons contribution. This fact seems imputable to space charge effect negatively affecting emission from dispenser cathodes, chosen for the intermediate electrode design. Some beneficial effect on thruster performance due to the presence of the active intermediate electrode has been observed at lowest powers, where possibly the weight of the intermediate electrode current with respect to the total discharge current is higher.

Primary mission objective of the COSMO-SkyMed system is the provision of an operational Earth Observation Endto-End Service able to fast answering to the user needs. End-To-End Service is based on a reliable, secure and flexible system capable of generating and distributing that service in terms of basic products and value added products. COSMO-SkyMed is a complex System, composed by a Space Segment, a distributed Ground Segment and an Integrated Logistic Support & Operations (ILSO presenting the topdown approach, the development process and the advantages in terms of cost optimization and end-to end performance achievement.

In the framework of the USV program, carried on within the Italian Aerospace Research Program, a trade-off analysis has been performed aimed at defining the configuration and the mission profile of a future experimental Flight Test Bed, called FTB-X, devoted to reentry flight experiments. FTB-X shall exhibit well improved aerodynamic and maneuverability characteristics, allowing to perform longer endurance re-entry patterns, as compared to conventional lifting re-entry vehicles, and therefore increasing related operability and safety margins. The long-duration mission requirement is particularly challenging from the point of view of Thermal Protection System (TPS) Design, because it has a direct impact on the type and on the thickness of the insulator used to protect internal structures and equipment. Moreover, a critical issue is the small radius of the nose and of the wing leading edge due to the need to guarantee a high aerodynamic efficiency. The performed thermal analysis and the proposed solutions for the TPS are described in the paper, together with the open points to be more deeply investigated in the next phases of the activity.

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INTRODUCTION Generally speaking, space has not been considered so far as a key player in new technologies. It is more a fast follower, the reason being the long and costly qualification programs which are directly linked to the combination of long life time (15 years for GEO satellites) and operation in harsh environment. Nevertheless the satellite industry could experience in the coming years, its biggest evolution since it joined the ranks of commerce. Thanks to increasing constraints on performance, cost and development cycles, it is possible that space industry could be at the cutting edge of the major technical evolution which is taking place in electronic industry. In some cases this evolution is going jointly with another low volume high added value industry : the military industry. In this paper, we will present and discuss Alcatel Space view in RF MEMS emerging technologies that may impact future telecom payload.

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(de)Photonic crystals, silicia, superprism, vertical straylight method

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(de)Railroad, train control, signalling, driverless, automatic operation, obstacle detection, ill

3R regeneration using different optical techniques is demonstrated up to 40 Gbits/s, covering a large spectrum of applications domains. New key property like WDM regeneration is also proven. But the deployment of such devices will be intimately linked to the capacity to implement simple, compact (integration), reliable structures with high performance and high bit rate potential levels.

This paper presents the research work carried out in the GEOCAST project, funded within the European 5 th Framework IST programme. It describes the challenges when using satellites for IP multicast, concerning networking technologies, satellite communications payload, IP multicast protocols, the role of satellites in the network and, in particular, the paper focuses on security. There are various security standards such as DVB-S, DVB-RCS, ATM and IPSec that can be applied to satisfy some of the user and network requirements. The paper provides an overview of these issues and the possible interaction between them. Then it examines in detail the topic of securing very large multicast groups, where the group size and group dynamics have great impact on networks and network security. It also presents key management distribution systems and a satellite key distribution architecture.

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