Alcatel-Lucent

About: Alcatel-Lucent is a based out in Stuttgart, Germany. It is known for research contribution in the topics: Signal & Network packet. The organization has 37003 authors who have published 53332 publications receiving 1430547 citations. The organization is also known as: Alcatel-Lucent S.A. & Alcatel.

Superconductivity in YBa2Cu3O7 single crystals

Abstract: Increased understanding of fundamental properties of the new cuprate superconductors depends on advances in the preparation of quality materials for study. Early work focused on the study of sintered polycrystalline samples. In some cases, grain growth during sintering yielded individual grains large enough (˜80 μm) for single crystal X-ray determination1. Larger single crystals allow measurements of physical properties including measurements of anisotropic behaviour. The anisotropy of upper critical fields in YBa2Cu3O7 single crystals has been reported by lye et al.2 who found critical fields characteristic of a quasi-two-dimensional superconductor, which are highest when the field is orientated perpendicular to the c-axis. Dinger et al.3 have measured critical fields and critical currents of single crystals and find anisotropies of 10 and greater3. These studies contain little detail on the crystal growth of YBa2Cu3O7. Here we report the growth of single crystals as large as 4 mm of YBa2Cu3O7 and DyBa2Cu3O7 and confirm superconductivity in them by magnetic and electrical measurements. Single crystals of other rare earth barium cuprates are also obtained although we have yet to optimize growth conditions for these phases.

Automatic composition of transition-based semantic web services with messaging

Abstract: In this paper we present Colombo, a framework in which web services are characterized in terms of (i) the atomic processes (i.e., operations) they can perform; (ii) their impact on the "real world" (modeled as a relational database); (iii) their transition-based behavior; and (iv) the messages they can send and receive (from/to other web services and "human" clients). As such, Colombo combines key elements from the standards and research literature on (semantic) web services. Using Colombo, we study the problem of automatic service composition (synthesis) and devise a sound, complete and terminating algorithm for building a composite service. Specifically, the paper develops (i) a technique for handling the data, which ranges over an infinite domain, in a finite, symbolic way, and (ii) a technique to automatically synthesize composite web services, based on Propositional Dynamic Logic.

Providing cloud-based services using dynamic network virtualization

Abstract: The invention is directed to providing cloud-based services using dynamic network virtualization. Embodiments of the invention provide a cloud-based service over a system that has a dynamic network virtualization architecture. The architecture includes a set of distributed forwarding elements with centralized control, and at least one virtual machine that is bound to one of the forwarding elements. These features enable the virtual machine to be migrated across a wide area network while maintaining its original IP address and service continuity.

Synchronized presentation of television programming and internet content

Abstract: Uniform Resource Locators (URLs) or other network information identifiers are transmitted with television signals in order to permit web content to be displayed in synchronization with television programming. In an illustrative embodiment, URLs are embedded in a closed caption portion of a transmitted television signal, and delimited from the closed caption text using predetermined delimiting characters. A decoder extracts the URLs from the television signal, and supplies the URLs to a retrieval device which automatically retrieves corresponding web pages or other similar information over a network. The retrieved web pages are then displayed to a viewer in synchronization with related programming in the television signal. The retrieval device may be a set-top box associated with a television set that displays both a retrieved web page and the corresponding television picture portion of the television signal. Alternatively, the retrieval device may be a computer which retrieves and displays a web page, while the corresponding television picture is displayed on a television set.

WTCP: a reliable transport protocol for wireless wide-area networks

Abstract: Wireless wide-area networks (WWANs) are characterized by very low and variable bandwidths, very high and variable delays, significant non-congestion related losses, asymmetric uplink and downlink channels, and occasional blackouts. Additionally, the majority of the latency in a WWAN connection is incurred over the wireless link. Under such operating conditions, most contemporary wireless TCP algorithms do not perform very well. In this paper, we present WTCP, a reliable transport protocol that addresses rate control and reliability over commercial WWAN networks such as CDPD. WTCP is rate-based, uses only end-to-end mechanisms, performs rate control at the receiver, and uses inter-packet delays as the primary metric for rate control. We have implemented and evaluated WTCP over the CDPD network, and also simulated it in the ns-2 simulator. Our results indicate that WTCP can improve on the performance of comparable algorithms such as TCP-NewReno, TCP-Vegas, and Snoop-TCP by between 20% to 200% for typical operating conditions.