Showing papers by "Alcatel-Lucent published in 2008"

An overview of limited feedback in wireless communication systems

Abstract: It is now well known that employing channel adaptive signaling in wireless communication systems can yield large improvements in almost any performance metric. Unfortunately, many kinds of channel adaptive techniques have been deemed impractical in the past because of the problem of obtaining channel knowledge at the transmitter. The transmitter in many systems (such as those using frequency division duplexing) can not leverage techniques such as training to obtain channel state information. Over the last few years, research has repeatedly shown that allowing the receiver to send a small number of information bits about the channel conditions to the transmitter can allow near optimal channel adaptation. These practical systems, which are commonly referred to as limited or finite-rate feedback systems, supply benefits nearly identical to unrealizable perfect transmitter channel knowledge systems when they are judiciously designed. In this tutorial, we provide a broad look at the field of limited feedback wireless communications. We review work in systems using various combinations of single antenna, multiple antenna, narrowband, broadband, single-user, and multiuser technology. We also provide a synopsis of the role of limited feedback in the standardization of next generation wireless systems.

The Sixth Data Release of the Sloan Digital Sky Survey

Abstract: This paper describes the Sixth Data Release of the Sloan Digital Sky Survey. With this data release, the imaging of the northern Galactic cap is now complete. The survey contains images and parameters of roughly 287 million objects over 9583 deg(2), including scans over a large range of Galactic latitudes and longitudes. The survey also includes 1.27 million spectra of stars, galaxies, quasars, and blank sky ( for sky subtraction) selected over 7425 deg2. This release includes much more stellar spectroscopy than was available in previous data releases and also includes detailed estimates of stellar temperatures, gravities, and metallicities. The results of improved photometric calibration are now available, with uncertainties of roughly 1% in g, r, i, and z, and 2% in u, substantially better than the uncertainties in previous data releases. The spectra in this data release have improved wavelength and flux calibration, especially in the extreme blue and extreme red, leading to the qualitatively better determination of stellar types and radial velocities. The spectrophotometric fluxes are now tied to point-spread function magnitudes of stars rather than fiber magnitudes. This gives more robust results in the presence of seeing variations, but also implies a change in the spectrophotometric scale, which is now brighter by roughly 0.35 mag. Systematic errors in the velocity dispersions of galaxies have been fixed, and the results of two independent codes for determining spectral classifications and red-shifts are made available. Additional spectral outputs are made available, including calibrated spectra from individual 15 minute exposures and the sky spectrum subtracted from each exposure. We also quantify a recently recognized underestimation of the brightnesses of galaxies of large angular extent due to poor sky subtraction; the bias can exceed 0.2 mag for galaxies brighter than r = 14 mag.

Temperature-dependent transport in suspended graphene.

Abstract: The resistivity of ultraclean suspended graphene is strongly temperature ($T$) dependent for $5lTl240\text{ }\text{ }\mathrm{K}$ At $T\ensuremath{\sim}5\text{ }\text{ }\mathrm{K}$ transport is near-ballistic in a device of $\ensuremath{\sim}2\text{ }\text{ }\ensuremath{\mu}\mathrm{m}$ dimension and a mobility $\ensuremath{\sim}170\text{ }000\text{ }\text{ }{\mathrm{cm}}^{2}/\mathrm{V}\text{ }\mathrm{s}$ At large carrier density, $ng05\ifmmode\times\else\texttimes\fi{}{10}^{11}\text{ }\text{ }{\mathrm{cm}}^{\ensuremath{-}2}$, the resistivity increases with increasing $T$ and is linear above 50 K, suggesting carrier scattering from acoustic phonons At $T=240\text{ }\text{ }\mathrm{K}$ the mobility is $\ensuremath{\sim}120\text{ }000\text{ }\text{ }{\mathrm{cm}}^{2}/\mathrm{V}\text{ }\mathrm{s}$, higher than in any known semiconductor At the charge neutral point we observe a nonuniversal conductivity that decreases with decreasing $T$, consistent with a density inhomogeneity $l{10}^{8}\text{ }\text{ }{\mathrm{cm}}^{\ensuremath{-}2}$

An overview of the femtocell concept

Abstract: The femtocell concept aims to combine fixed-line broadband access with cellular telephony using the deployment of ultra-low-cost, low-power third generation (3G) base stations in the subscribers' homes or premises. It enables operators to address new markets and introduce new high-speed services and disruptive pricing strategies to capture wireline voice minutes and to grow revenues. One of the main design challenges of the femtocell is that the hierarchical architecture and manual cell planning processes used in macrocell networks do not scale to support millions of femtocells. In this paper, a user-deployed femtocell solution based on the base station router (BSR) flat Internet Protocol (IP) cellular architecture is presented that addresses these problems, and several aspects of the proposed solution are discussed. The overall concept and key requirements are presented in detail. The auto-configuration and self-optimization process from purchase by the end user to the integration into an existing macrocellular network is described. Then the theoretical performance of a co-channel femtocell deployment is analyzed and its impact on the macrocell underlay is assessed. Finally, a financial analysis of a femtocellular home base station deployment in a macrocellular network is presented. It is shown that in urban areas, the deployment of publicly accessible home base stations with slightly increased coverage can significantly reduce the operator's annual network costs (up to 70 percent in the investigated scenario) compared to a pure macrocellular network.

Nanonails: a simple geometrical approach to electrically tunable superlyophobic surfaces.

Abstract: In this work, dynamically tunable, superlyophobic surfaces capable of undergoing a transition from profound superlyophobic behavior to almost complete wetting have been demonstrated for the first time. In the initial state, with no voltage applied, these surfaces exhibit contact angles as high as 150° for a wide variety of liquids with surface tensions ranging from 21.8 mN/m (ethanol) to 72.0 mN/m (water). Upon application of an electrical voltage, a transition from the superlyophobic state to wetting is observed. We have examined experimentally and theoretically the nature of these transitions. The reported results provide novel methods of manipulating liquids on the microscale.

Methods and entities using IPSec ESP to support security functionality for UDP-based traffic

Abstract: Methods in OMA SEC_CF for providing security services to traffic over UDP between a client and a server and the relevant entities are provided. A pre-shared key is pre-shared between the client and the server. A pair of IPSec ESP SAs between the client and the server is established without shared key negotiation, wherein traffic data cryptographic algorithms are determined. Traffic data security keys are derived from the pre-shared key via the determined traffic data cryptographic algorithms. Then, data of the traffic can be provided with security services with the traffic data security keys through use of IPSec ESP.

Quasi-particle properties from tunneling in the v = 5/2 fractional quantum Hall state.

Abstract: Quasi-particles with fractional charge and statistics, as well as modified Coulomb interactions, exist in a two-dimensional electron system in the fractional quantum Hall (FQH) regime. Theoretical models of the FQH state at filling fraction \(v={^{5}}/{_{2}}\) make the further prediction that the wave function can encode the interchange of two quasi-particles, making this state relevant for topological quantum computing. We show that bias-dependent tunneling across a narrow constriction at \(v={^{5}}/{_{2}}\) exhibits temperature scaling and, from fits to the theoretical scaling form, extract values for the effective charge and the interaction parameter of the quasi-particles. Ranges of values obtained are consistent with those predicted by certain models of the \({^{5}}/{_{2}}\) state.

Mediation of the solar wind termination shock by non-thermal ions

Abstract: Broad regions on both sides of the solar wind termination shock are populated by high intensities of non-thermal ions and electrons. The pre-shock particles in the solar wind have been measured by the spacecraft Voyager 1 (refs 1-5) and Voyager 2 (refs 3, 6). The post-shock particles in the heliosheath have also been measured by Voyager 1 (refs 3-5). It was not clear, however, what effect these particles might have on the physics of the shock transition until Voyager 2 crossed the shock on 31 August-1 September 2007 (refs 7-9). Unlike Voyager 1, Voyager 2 is making plasma measurements. Data from the plasma and magnetic field instruments on Voyager 2 indicate that non-thermal ion distributions probably have key roles in mediating dynamical processes at the termination shock and in the heliosheath. Here we report that intensities of low-energy ions measured by Voyager 2 produce non-thermal partial ion pressures in the heliosheath that are comparable to (or exceed) both the thermal plasma pressures and the scalar magnetic field pressures. We conclude that these ions are the >0.028 MeV portion of the non-thermal ion distribution that determines the termination shock structure and the acceleration of which extracts a large fraction of bulk-flow kinetic energy from the incident solar wind.

Method and system for mobility across heterogeneous address spaces

Abstract: A mobile node includes a processor, a network interface, and a storage device having computer program code for execution by the processor. The computer program code includes a network layer for transmitting and receiving packets and an intermediate driver that transmits packets to the network layer and receives packets from the network layer using a virtual internet protocol (IP) address to identify the mobile node. The intermediate driver transmits packets to the network interface and receives packets from the network interface using a routable actual IP address to identify the mobile node. The intermediate driver permits the actual IP address to change when the mobile node moves from a first subnet to a second subnet without a corresponding change in the virtual IP address. A corresponding NAT associates the virtual IP address with a second actual IP address when the NAT is notified that the mobile node is in the second subnet.

Dual-polarized wireless communications: from propagation models to system performance evaluation

Abstract: In this paper, we address the potential benefits of dual-polarized arrays in multi-antenna wireless systems. After an extensive literature overview of experimental data, we present a new and simple analytical framework to model dual-polarized Rayleigh and Ricean fading channels for arbitrary array sizes. The model relies on a limited number of physical parameters, such as the channel spatial correlations, the channel co-polar and the cross-polar ratios and the antenna cross-polar discrimination. Then, we investigate the multiplexing advantage of dual-polarized transmissions through the evaluation of the ergodic mutual information, for both TITO and MIMO systems. Finally, the performance of two space-time coding schemes (Alamouti OSTBC and uncoded spatial multiplexing) is evaluated via a detailed analysis of the pairwise error probability.

Analysis of Respiratory Sounds: State of the Art

Abstract: Objective: This paper describes state of the art, scientific publications and ongoing research related to the methods of analysis of respiratory sounds. Methods and material: Review of the current medical and technological literature using Pubmed and personal experience. Results: The study includes a description of the various techniques that are being used to collect auscultation sounds, a physical description of known pathologic sounds for which automatic detection tools were developed. Modern tools are based on artificial intelligence and on technics such as artificial neural networks, fuzzy systems, and genetic algorithms… Conclusion: The next step will consist in finding new markers so as to increase the efficiency of decision aid algorithms and tools.

Information-guided channel-hopping for high data rate wireless communication

Abstract: In this letter, we introduce information-guided channel-hopping, a new scheme for high data rate communication over Rayleigh fading channel using multiple transmit antennas. This scheme is proposed based on the fact that the independence character of multi-channel can be used as an additional information transmitting channel, and the maximum likelihood decoding can be achieved in a simple way by decoupling of the signals conveyed by different methods. The analysis results prove that the capacity behavior of this scheme is better than that of the space-time block coding for more than two transmit antennas.

Short message service communication security

Abstract: A system, method, and device for securely forwarding SMS messages in a communication system, for example in a communication system including an IMS network accessible to wireless devices via a radio access network. The communication system forwards SMS messages from a sending station to a receiving station via a network node. The network node, which may be an SMSC in an IMS network, is operable to determine whether the SMS message is encrypted and whether the intended recipient supports encryption, and then the network node selectively encrypts and decrypts received SMS messages prior to forwarding to the intended recipient; SMS messages received unencrypted are encrypted by the SMS message encrypter/decrypter if the intended recipient supports encryption, and SMS messages received encrypted are decrypted by the SMS message encrypter/decrypter if the intended recipient does not support SMS message encryption. SMS messages intended for a recipient determined not to support SMS message encryption may be stored in a holding database, and an alert send to the intended recipient, if the sender requires that the SMS message be sent only in encrypted form.

Mobility Aware Policy and Charging Control in a Wireless Communication Network

Abstract: One embodiment of the present invention provides a method for implementation in a policy control and charging rules functional entity in a wireless communication system. The method includes receiving, from at least one of a source policy and charging enforcement function in a source access network or a target policy and charging enforcement function in a target access network, information indicative of a mobile unit that has handed off from the source access network to the target access network. The method also includes establishing a first session for communicating policy and charging rules associated with the mobile unit. The first session is concurrent with a second session for communicating policy and charging rules associated with the mobile unit. The second session was previously established with the source policy and charging enforcement function in the source access network. The method further includes transmitting at least one policy and charging rule to the target policy and charging enforcement function using the first session.

Electronic Dispersion Compensation

Abstract: The performance of different electronic equalization and processing schemes for 40- and 10-Gb/s optical transmission over single-mode fiber (SMF) are discussed, from the point of their ability to compensate chromatic dispersion (CD) and polarization mode dispersion (PMD). In addition, the impact of fiber nonlinearity and modulation format on equalization is also investigated. The main objective of this paper is to present an overview and a comparison of the performances rather than a detailed explanation of the principles of the different equalization schemes. The equalizers which will be covered are analog equalizer (feedforward and decision feedback type), maximum likelihood sequence estimator (MLSE), electronic precompensation, coherent/intradyne detection with digital signal processing (DSP) equalization, DSP-based optical orthogonal frequency division multiplexing (OFDM), and turbo equalization.

Resilient service quality in a managed multimedia delivery network

Abstract: A managed multimedia delivery network (1) for providing a multimedia service with resilient service quality is disclosed. The network comprising a plurality of caching nodes (3) for caching multimedia data segments; an edge caching node (4) for colleting requested multimedia data segments from the caching nodes (3) and for serving a user equipment (2) with the collected multimedia data; and a service gateway (5) for providing cache information to the edge caching node (4) indicating how to obtain the requested multimedia data segments from the caching nodes (3). The edge caching node (4) comprises a service quality monitoring unit for monitoring the collection of the data segments from the caching nodes (3) and for requesting cache information from the service gateway (5) when the collection of data segments impacts the service quality.

Measurement of the Casimir force between a gold sphere and a silicon surface with nanoscale trench arrays.

Abstract: We report measurements of the Casimir force between a gold sphere and a silicon surface with an array of nanoscale, rectangular corrugations using a micromechanical torsional oscillator. At distances between 150 and 500 nm, the measured force shows significant deviations from the pairwise additive formulism, demonstrating the strong dependence of the Casimir force on the shape of the interacting bodies. The observed deviation, however, is smaller than the calculated values for perfectly conducting surfaces, possibly due to the interplay between finite conductivity and geometry effects.

25.6-Tb/s WDM Transmission of Polarization-Multiplexed RZ-DQPSK Signals

Abstract: We demonstrate record 25.6-Tb/s transmission over 240 km using 160 WDM channels on a 50-GHz grid in the C+L bands. Each channel contains two polarization-multiplexed 85.4-Gb/s RZ-DQPSK signals, yielding a spectral efficiency of 3.2b/s/Hz in each band.

Charge fractionalization in quantum wires

Abstract: Although the unit of charge in nature is a fundamental constant, the charge of individual quasiparticles in some low-dimensional systems may be fractionalized. Quantum one-dimensional (1D) systems, for instance, are theoretically predicted to carry charge in units smaller than the electron charge e. Unlike 2D systems, the charge of these excitations is not quantized and depends directly on the strength of the Coulomb interactions. For example, in a 1D system with momentum conservation, it is predicted that the charge of a unidirectional electron that is injected into the wire decomposes into right- and left-moving charge excitations carrying fractional charges f0e and (1−f0)e respectively1,2. f0 approaches unity for non-interacting electrons and is less than one for repulsive interactions. Here, we provide the first experimental evidence for charge fractionalization in one dimension. Unidirectional electrons are injected at the bulk of a wire and the imbalance in the currents detected at two drains on opposite sides of the injection region is used to determine f0. Our results elucidate further3,4 the collective nature of electrons in one dimension.

Method and system for IP multimedia bearer path optimization through a succession of border gateways

Abstract: A method for identifying alternative end-to-end media paths through Internet protocol realms using substitute session description protocol parameters is disclosed. The method includes receiving a session description protocol offer, including a list of internet protocol realms. The list may include any number of previously traversed through internet protocol realms and/or secondary Internet protocol realms. The method continues with determining the outgoing Internet protocol realm for a media path based on unspecified signaling criteria. Finally, the method includes that if the outgoing Internet protocol realm to be traversed through is on the list of previously traversed through and/or secondary Internet protocol realms, bypassing at least one border gateway associated with the incoming and previously traversed through Internet protocol realms. The system implementing a method for identifying optimal end-to-end media paths and Internet protocol multimedia subsystems includes a list of internet protocol realm instances and an application level gateway configured to receive a session description protocol offer having connection information and port information, and a procedure to determine that if the outgoing Internet protocol realm that the media path may traverse through is on the list of instances, the media path connection information and port information is substituted to facilitate border gateway bypassing.

A method and device used in radio relay networks to re-construct the topology of networks

Abstract: A solution to re-construct the topology of networks according to cells' service-correlation information and to realize self-optimization of networks is disclosed. Said cells' service-correlation information includes service-correlation information which can be used to re-construct the topology of networks, or so-called load-correlation information including but not limiting to time-frequency resources correlation amount used by service data of said cells, cells' throughput or QoS of radio channel on which cells' service data are transmitted. Said solution re-constructs the topology of networks according to cells' service-correlation information, and thus the capacity and QoS of networks are improved efficiently, which enable radio relay networks to serve in service distributing indeterminable area. The function of re-construction the topology of networks in said solution could simplify networks management and save the fee of networks management.

Enhancement to sip forking for improved user services

Abstract: A method of enhancing SIP forking for offering improved call services in a telecommunication network is disclosed. An endpoint of the network is assigned as a Forking Master for providing improved call services for a user in the same Address of Record (AoR) in the presence of forking. The method of assigning a forking master comprises of user provisioning, updating by the user terminal during registration, subsequent declaration by the user terminal, third-party assignment and network- triggered assignment. An endpoint can take up or relinquish the role of Forking Master by specifying the value 'true' or false' for the forking-master parameter. The Forking Master can be associated with call completion services, presence-based services, call- forwarding interaction, lawful interception, facilities like PBRT and the like.

Radio Transmitter Fingerprinting: A Steady State Frequency Domain Approach

Abstract: We present a novel technique for radio transmitter identification based on frequency domain characteristics. Our technique detects the unique features imbued in a signal as it passes through a transmit chain. We are the first to propose the use of discriminatory classifiers based on steady state spectral features. In laboratory experiments, we achieve 97% accuracy at 30 dB SNR and 66% accuracy at OdB SNR based on eight identical universal software radio peripherals (USRP) transmitters. Our technique can be implemented using today's low cost high-volume receivers and requires no manual performance tuning.

Control for the interface for sending an SIP reply message

Abstract: In one embodiment a communication client, includes at least one sending interface to send a signaling message in accordance with the SIP protocol, towards a first interface of a communication server. The client and server are connected by a communication network. The communication client is suitable for inserting an indication within the signaling message regarding the interface for the communication server to use to send its response signaling message.

Neurite outgrowth on a DNA crosslinked hydrogel with tunable stiffnesses.

Abstract: Mechanical cues arising from extracellular matrices greatly affect cellular properties, and hence, are of significance in designing biomaterials. In this study, a DNA crosslinked hydrogel was employed to examine cellular responses of spinal cord neurons to substrate compliances. Using DNA as crosslinkers in polymeric hydrogel formation has given rise to a new class of hydrogels with a number of attractive properties (e.g., reversible gelation and controlled crosslinking). Here, it was demonstrated that by varying length of crosslinker, monomer concentration, and level of crosslinking, DNA gel stiffnesses span from approximately 100 Pa to 30 kPa. Assessment of neurite outgrowth on functionalized DNA gels showed that although primary dendrite length is not significantly affected, spinal cord neurons extend more primary dendrites and shorter axons on stiffer gels. Additionally, a greater proportion of neurons have more primary dendrites and shorter axons on stiffer gels. There is a pronounced reduction in focal adhesion kinase (FAK) when neurons are exposed to stiffer substrates, suggesting its involvement in neuronal mechanosensing and neuritogenesis in response to stiffness. These results demonstrate the importance of mechanical aspects of the cell-ECM interactions, and provide guidance for the design of mechanical properties of bio-scaffolds for neural tissue engineering applications.

Transmission of 16.4Tbit/s Capacity over 2,550km using PDM QPSK Modulation Format and Coherent Receiver

Abstract: A record capacityxdistance product of 41.8Petabit/s.km is demonstrated. 164 channels are modulated at 100Gbit/s with PDM-QPSK format, packed with 2bit/s/Hz information spectral density, and recovered by off-line processing in a coherent receiver after 2550km distance.

Method of controlling a power grid

Abstract: The invention concerns a method of controlling a power grid and a control server. The control server (4) comprises communication means (41), a data base (43) and a control unit (42) adapted to execute the method of controlling a power grid. The control server (4) receives information about utilities energy data from a utilities provider (5). The control server (4) receives information about consumer energy data from a plurality of smart-meters (21, 22). The control server (4) performs a load balancing evaluation based on the received information about utilities energy data and on the received information about consumer energy data. The control server (4) generates consumer energy information based on results of the load balancing evaluation and on energy management data associated with a respective consumer (61, 62) and extracted from a data base (43) and sends the generated consumer energy information to a user device (3) and/or a smart-meter (21, 22), wherein the user device (3) is associated with the smart-meter (21, 22).

Method and apparatus for network managed radio frequency coverage and mobile distribution analysis using mobile location information

Abstract: A system and method for identifying geographical areas which distribute poor radio frequency coverage is provided. The method includes measuring a radio frequency signal of a mobile unit in response to a trigger. The method continues with mapping the location data of the radio frequency signal which represents the positioning of the mobile unit at a given time. The method continues with recording the location data of the mobile unit and storing the location data in a database. The trigger, which prompts the radio frequency measurement, may be a timer expiring, a dropped call, or a mobile power increase signaling a weak signal. In any form, a post processing module may be configured in order to record, store and organize the location data into a report, such as a coverage map. Embodiments of this disclosure will display geographic areas that have poor radio frequency and allow for an administrator to identify trouble spots by a geographical region.

Handover from e-utran to utran/geran cs

Abstract: The present invention relates to a method for a handover of a UE (User Equipment) currently engaged in a voice call. More particularly, the invention relates to a handover from 1) a packet based radio where Voice Service is provided via VoIP over the radio and is controlled via Session Initiation Protocol (SIP) based signalling (e.g. LTE, E-UTRAN or WIMAX radio) to 2) a radio access network where Voice Service can be only provided via circuit switched (CS) domain (a visited mobile switching centre (VMSC) is needed) such as legacy 3GPP UMTS Terrestrial Radio Access Network (UTRAN)/ GSM/Edge Radio Access Network (GERAN) coverage. A MSC-S entity acting as a Packet Core Control Node on a Packet Switched (PS) network and as an Anchor Visited Mobile Switching Centre (VMSC) for a handover to a Circuit Switched (CS) network on the CS domain side is proposed, the MSC-S preparing a new path with a remote UE-B and a CS domain handover towards a target legacy radio coverage before requesting a UE- A to execute the handover.