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.

UCAN: a unified cellular and ad-hoc network architecture

Abstract: In third-generation (3G) wireless data networks, mobile users experiencing poor channel quality usually have low data-rate connections with the base-station. Providing service to low data-rate users is required for maintaining fairness, but at the cost of reducing the cell's aggregate throughput. In this paper, we propose the Unified Cellular and Ad-Hoc Network (UCAN) architecture for enhancing cell throughput, while maintaining fairness. In UCAN, a mobile client has both 3G cellular link and IEEE 802.11-based peer-to-peer links. The 3G base station forwards packets for destination clients with poor channel quality to proxy clients with better channel quality. The proxy clients then use an ad-hoc network composed of other mobile clients and IEEE 802.11 wireless links to forward the packets to the appropriate destinations, thereby improving cell throughput. We refine the 3G base station scheduling algorithm so that the throughput gains of active clients are distributed proportional to their average channel rate, thereby maintaining fairness. With the UCAN architecture in place, we propose novel greedy and on-demand protocols for proxy discovery and ad-hoc routing that explicitly leverage the existence of the 3G infrastructure to reduce complexity and improve reliability. We further propose a secure crediting mechanism to motivate users to participate in relaying packets for others. Through extensive simulations with HDR and IEEE 802.11b, we show that the UCAN architecture can improve individual user's throughput by up to 310% and the aggregate throughput of the HDR downlink by up to 60%.

TTP/spl minus/a protocol for fault-tolerant real-time systems

Abstract: The Time-Triggered Protocol integrates such services as predictable message transmission, clock synchronization, membership, mode change, and blackout handling. It also supports replicated nodes and replicated communication channels. The authors describe their architectural assumptions, fault hypothesis, and objectives for the TTP protocol. After they elaborate on its rationale, they give a detailed protocol description. They also discuss TTP characteristics and compare its performance with that of other protocols proposed for control applications. >

Tripling the capacity of wireless communications using electromagnetic polarization

Abstract: Wireless communications are a fundamental part of modern information infrastructure. But wireless bandwidth is costly, prompting a close examination of the data channels available using electromagnetic waves. Classically, radio communications have relied on one channel per frequency, although it is well understood that the two polarization states of planar waves allow two distinct information channels; techniques such as 'polarization diversity' already take advantage of this. Recent work has shown that environments with scattering, such as urban areas or indoors, also possess independent spatial channels that can be used to enhance capacity greatly. In either case, the relevant signal processing techniques come under the heading of 'multiple-input/multiple-output' communications, because multiple antennae are required to access the polarization or spatial channels. Here we show that, in a scattering environment, an extra factor of three in channel capacity can be obtained, relative to the conventional limit using dual-polarized radio signals. The extra capacity arises because there are six distinguishable electric and magnetic states of polarization at a given point, rather than two as is usually assumed.

Consumer ethnocentrism and attitudes toward domestic and foreign products

Abstract: Investigates the relationship between consumer ethnocentrism and consumer attitudes toward foreign manufactured products in product categories in which domestic alternatives are not available. Such decision situations (i.e. product choice in categories with no domestic alternative) are common for consumers in many smaller countries throughout Europe, and thus important for marketing managers to understand. It was hypothesised that individuals with high levels of consumer ethnocentrism would have more favourable attitudes toward products from culturally similar countries in comparison to products from culturally dissimilar countries. The values classification of culture proposed by Schwartz was used to establish cultural similarity, and the attitudes of a representative sample of New Zealand consumers were assessed using a nation‐wide mail survey. Our results suggest that cultural similarity is an important consideration for highly ethnocentric consumers in the evaluation of foreign products. A number of theoretical and managerial implications are discussed.

Statistical signatures of photon localization

Abstract: The realization that electron localization in disordered systems1 (Anderson localization) is ultimately a wave phenomenon2,3 has led to the suggestion that photons could be similarly localized by disorder3. This conjecture attracted wide interest because the differences between photons and electrons—in their interactions, spin statistics, and methods of injection and detection—may open a new realm of optical and microwave phenomena, and allow a detailed study of the Anderson localization transition undisturbed by the Coulomb interaction. To date, claims of three-dimensional photon localization have been based on observations of the exponential decay of the electromagnetic wave4,5,6,7,8 as it propagates through the disordered medium. But these reports have come under close scrutiny because of the possibility that the decay observed may be due to residual absorption9,10,11, and because absorption itself may suppress localization3. Here we show that the extent of photon localization can be determined by a different approach—measurement of the relative size of fluctuations of certain transmission quantities. The variance of relative fluctuations accurately reflects the extent of localization, even in the presence of absorption. Using this approach, we demonstrate photon localization in both weakly and strongly scattering quasi-one-dimensional dielectric samples and in periodic metallic wire meshes containing metallic scatterers, while ruling it out in three-dimensional mixtures of aluminium spheres.