Showing papers by "Telcordia Technologies published in 1994"

Synthesis Conditions and Oxygen Stoichiometry Effects on Li Insertion into the Spinel LiMn2O4

Abstract: Using a new electrolyte composition which is stable against oxidation up to 5 V, the full electrochemical deintercalation of lithium from the spinel LiMn[sub 2]O[sub 4], is studied. The origin of two new reversible oxidation-reduction peaks near 4.5 and 4.9 V are examined. The capacity associated with these peaks depends on both the nominal composition x in Li[sub x]Mn[sub 2]O[sub 4] and the synthesis conditions (annealing temperatures and cooling rates), and thereby can be used as an indicator for electrochemically optimized LiMn[sub 2]O[sub 4] powders. The authors present evidence that these peaks are related to local structural defects. Thermogravimetric measurements (TGA) on Li[sub x]Mn[sub 2]O[sub 4] powders show a reversible loss of oxygen that can reach 5% at 1,000 C. The authors find that some of this weight loss is associated with the conversion of cubic LiMn[sub 2]O[sub 4] to a new tetragonal spinel phase and then to the decomposition of this phase into the orthorhombic LiMnO[sub 2] phase plus other products. This new tetragonal LiMn[sub 2]O[sub 4] spinel is prepared as a single phase, and its electrochemical properties are reported.

Method and system for managing telecommunications such as telephone calls

Abstract: A method and system for managing telephone calls includes a personal telephone manager (PTM) (12) and uses out-of-band, wireless, two-way signaling, messaging and alerting to screen, control, route and respond to incoming telephone calls and to communicate called party text messages in auditory form to the caller. Using an out-of-band signaling/messaging path (16), the PTM (12) frees the called party from the need to maintain telephone network connectivity, from having to inform others of his/her current location, and from having to subscribe to and use cellular telephone service. Two-way wireless data messaging to a portable computer (18) equipped with radio transceivers is also provided. This feature enables the system to provide a set of real-time options including: call screening by the called party based on information identifying the caller's telephone number; call redirection to a wireline or wireless telephone number as specified by the called party; call redirection to a third party or to a voice mail system; or the return of a text message specified by the called party to the caller in auditory form.

Communications Architecture and Buffer for Distributing Information Services

Abstract: A store-and-forward architecture which stores and distributes information programs to subscribers includes: information warehouses which archive information programs and dispense information programs in segments to central offices in bursts; central offices which manage subscriber's requests for service and buffer segments of information programs for delivery to subscribers in real-time under the subscriber's interactive control; and customer premises equipment. The central offices employ CO buffers, and each CO buffer includes: processors (402, 405), for administering internal buffer operations and processing subscribers requests based upon the service presentation script and a program presentation map; interfaces (43, 46) for providing external access; busses (411, 412) for internal transport; buffer storage (403, 404) for storing segments of information programs; and memory storage (407, 413) for storing the script and map.

Call routing and the ratcatcher

Abstract: Suppose we expect there to bep(ab) phone calls between locationsa andb, all choices ofa, b from some setL of locations. We wish to design a network to optimally handle these calls. More precisely, a “routing tree” is a treeT with set of leavesL, in which every other vertex has valency 3. It has “congestion” 0 form the edges of a planar graphG, there is an efficient, strongly polynomial algorithm. This is because the problem is equivalent to deciding if a ratcatcher can corner a rat loose in the walls of a house with floor planG, wherep(ab) is a thickness of the wallab. The ratcatcher carries a noisemaker of powerk, and the rat will not move through any wall in which the noise level is too high (determined by the total thickness of the intervening walls between this one and the noisemaker). It follows that branch-width is polynomially computable for planar graphs—that too is NP-hard for general graphs.

Sound localization system for teleconferencing using self-steering microphone arrays

Abstract: A teleconferencing system (100) is disclosed having a video camera for generating a video signal representative of a video image of a first station B. A microphone array (150, 160) is also provided in the first station for receiving a sound from one or more fixed non-overlapping volume zones (151-159) into which the first station is divided. The microphone array is also provided for generating a monochannel audio signal (170) representative of the received sound and a direction signal indicating, based on the sound received from each zone, from which of the volume zones the sound originated. The teleconferencing system also includes a display device (120A) at a second station A for displaying a video image of the first station. A loudspeaker control device (140) is also provided at the second station for selecting a virtual location (121) on the displayed video image depending on the direction signal, and for generating stereo sound from the monochannel audio signal which stereo sound emanates from the virtual location on the displayed video image.

A caching strategy to reduce network impacts of PCS

Abstract: We propose an auxiliary strategy, called per-user caching, for locating users who move from place to place while using Personal Communications Services (PCS). The caching strategy augments the basic location strategy proposed in existing standards such as GSM and IS-41, with the objective of reducing network signaling and database loads in exchange for increased CPU processing and memory costs. Since technology trends are driving the latter costs down, the auxiliary strategy will become increasingly attractive. The idea behind caching is to reuse the information about a called user's location for subsequent calls to that user, and is useful for those users who receive calls frequently relative to the rate at which they change registration areas. This idea attempts to exploit the spatial and temporal locality in calls received by users, similar to the idea of exploiting locality of file access in computer systems. We use a reference PCS architecture and the notion of a user's local call-to-mobility ratio (LCMR) to quantify the costs and benefits of using caching and classes of users for whom it would be beneficial. We also present two simple algorithms for estimating users' LCMR and the situation in which each is preferable. We show that under a variety of assumptions caching is likely to yield significant net benefits in terms of reduced signaling network traffic and database loads. >

Experiences with a high-speed network adaptor: a software perspective

Abstract: This paper describes our experiences, from a software perspective, with the OSIRIS network adaptor. It first identifies the problems we encountered while programming OSIRIS and optimizing network performance, and outlines how we either addressed them in the software, or had to modify the hardware. It then describes the opportunities provided by OSIRIS that we were able to exploit in the host operating system (OS); opportunities that suggested techniques for making the OS more effective in delivering network data to application programs. The most novel of these techniques, called application device channels, gives application programs running in user space direct access to the adaptor. The paper concludes with the lessons drawn from this work, which we believe will benefit the designers of future network adaptors.

Rechargeable lithium intercalation battery with hybrid polymeric electrolyte

Abstract: A rechargeable battery comprises lithium intercalation compound electrodes (43, 47) and an interposed electrolyte of flexible polymer (45) containing a lithium salt dissolved in a polymer-compatible solvent. Preferred components include tertiary lithium manganese oxide compound positive electrodes, carbon negative electrodes, and poly(vinylidene fluoride) copolymer with 8 to 25 % by weight hexafluoropropylene electrolyte layers containing about 20 to 70 % of a solution of lithium salt in a medium-boiling solvent comprising such solvents as ethylene carbonate, propylene carbonate, and dimethyl carbonate. The electrolyte layer (45) may be employed in the form of an individual separator film or as a coated component of a multilayer battery structure to provide electrical ionic conductivity up to about 10-3 S/cm.

System and method for recording, playing back and searching multimedia events wherein video, audio and text can be searched and retrieved

Abstract: A system for recording and playing back multimedia events includes recording sources, a preprocessor, a delivery processor, and user control units. The recording sources each captures a continuous temporal record or track of the multimedia event and transmits the captured track to the source preprocessor where tracks are coded into digital blocks and digitized blocks of tracks received simultaneously are time stamped with the same relative time, and therefore synchronized in time. Tracks of the multimedia event are also compressed and preprocessed to generate other representations of the multimedia event, which further assist users in searching through the multimedia event. The delivery processor services users' requests for multimedia events and delivers events to requesting users according to users' interactive commands. The delivery processor also generates stacked representations of the tracks of the multimedia event, which representations provide visual cues to assist the user in conducting rapid and intelligent searches through the multimedia event. The user control unit receives requests and interactive commands from the user to be transmitted to the delivery processor and multimedia events from the delivery processor for presentation to the user. Our inventive method for recording and playing back multimedia events entails: capturing tracks of various aspects of a multimedia event; coding the tracks into digitized blocks; time stamping each block; and compressing and preprocessing each track as instructed in a source mapping table; transmitting tracks of the multimedia event to the user as requested; and adjusting the delivery of tracks based upon relative time information associated with a new position established after searching through a track of the multimedia event.

Network planning with random demand

Abstract: We study a planning problem associated with networks for private line services. In these networks, demands are known to exhibit considerable variability, and as such, they should be treated as random variables. The proposed planning model is a two-stage stochastic linear program (SLP) with recourse. Due to the enormous size of the deterministic equivalent, we choose a sampling based algorithm calledstochastic decomposition (SD). For very large-scale SLPs, such as the ones solved in this application, SD provides an effective methodology. The model presented in this paper is validated by using a detailed simulation of the network. We report results with a network that has 86 demand pairs, 89 links and 706 potential routes.

Automatic tracking camera control system

Abstract: Methodology and circuitry for automatically effecting electronic camera movement to track and display the location of a moving object, such as a person presenting a talk to an audience. A fixed spotting camera is used to capture a field of view, and a moving tracking camera with pan/tilt/zoom/focus functions is driven to the present location of the moving object. Information for driving the tracking camera is obtained with reference to the pixel difference between a current image and a previous image within the field of view. A tracking algorithm computes the information necessary to drive the tracking camera from these pixel differences as well as data relative to the field of view of the spotting camera and the present tracking camera position.

Two-way public key authentication and key agreement for low-cost terminals

Abstract: A method for achieving mutual authentication and session key agreement between a first party (12) that has a minimal computational resources and a second party (18) that has substantial computational resources uses a modular square root operation for certificate authentication and key distribution and an ELGamal, NIST DSS, or other efficient signature operation for obtaining the signature of a message. The second party (18) is connected to a switching system (23) in a central office (22).

Broadband intelligent telecommunications network and method employing a resource system to support network services

Abstract: A Broadband Intelligent Network employs an ATM fast-packet switch to route signaling cells from a calling party to a switch port directly connected to a Service Control Point (SCP) (61). The signaling cells carry a service request that requires the support of a network resource, and, in the specific case described herein, the support of the Line Information Data Base (LIDB) (150) to facilitate the establishment of a switched virtual connection to a called party (54). The SCP (61) acts on the information in the signaling cells and selects the required resource, i.e., the LIDB (150), and then sends a query cell(s) to the LIDB (150) through a permanent virtual connection in the ATM switch (51). The LIDB (150), in turn, acts on the information in the query cell(s) to assemble a response cell(s) with the requested information. The response cell(s) is sent to the SCP (61) through the permanent virtual connection in the ATM switch (51), thereby enabling the SCP to complete call processing, establish the requested connection, and generate a billing record (65).

Surface approximation and geometric partitions

Abstract: Motivated by applications in computer graphics, visualization, and scientic compu- tation, we study the computational complexity of the following problem: given a set S of n points sampled from a bivariate function f(x;y) and an input parameter "> 0, compute a piecewise-linear function (x;y) of minimum complexity (that is, an xy-monotone polyhedral surface, with a mini- mum number of vertices, edges, or faces) such thatj(xp;yp) i zp j" for all (xp;yp;zp)2 S.W e give hardness evidence for this problem, by showing that a closely related problem is NP-hard. The main result of our paper is a polynomial-time approximation algorithm that computes a piecewise- linear surface of size O(Ko logKo), where Ko is the complexity of an optimal surface satisfying the constraints of the problem. The technique developed in our paper is more general and applies to several other problems that deal with partitioning of points (or other objects) subject to certain geometric constraints. For instance, we get the same approximation bound for the following problem arising in machine learning: givenn \red" andm \blue" points in the plane, nd a minimum number of pairwise disjoint triangles such that each blue point is covered by some triangle and no red point lies in any of the triangles.

An optimization problem related to balancing loads on SONET rings

Abstract: We provide a model and a set of solution techniques for an important problem arising in the design of survivable telecommunication networks utilizing fiber-optics-based technologies. The emergence of a synchronous standard for optical signaling called "SONET" allows for an economic implementation of ring designs that provides protection for high capacity services. An objective is to choose a loading of the demands onto a ring design that minimizes associated equipment and facility costs while providing capacity for alternative routing should some link or node fail. After the computational complexity of the problem has been determined, three approximation heuristics, including a mathematical programming dual-ascent solution technique, are described and compared. The heuristics are being successfully applied to actual network design problems arising in Bell operating companies and other telecommunication providers.

Oriented ferroelectric La‐Sr‐Co‐O/Pb‐La‐Zr‐Ti‐O/La‐Sr‐Co‐O heterostructures on [001] Pt/SiO2 Si substrates using a bismuth titanate template layer

Abstract: We demonstrate the growth of c‐axis oriented La‐Sr‐Co‐O/Pb‐La‐Zr‐Ti‐O/La‐Sr‐Co‐O ferroelectric capacitor heterostructures on a highly [001] oriented Pt film which was grown on a thermally oxidized Si (SiO2/Si) substrate. The [001] growth orientation in the Pt film is induced by depositing it on a thin c‐axis oriented bismuth titanate template layer which is previously grown on the SiO2/Si substrate. The test capacitors show saturation and remnant polarization values comparable with that obtained on single‐crystal LaAlO3 substrates. The use of a Pt layer reduces the sheet resistance of the bottom electrode stack by at least 3–5 times. Since the Pt layer is strongly [001] oriented, it favors the growth of [001] La‐Sr‐Co‐O (LSCO) and lead zirconate titanate layers. The use of the LSCO top and bottom electrodes in contact with the ferroelectric thin film provides the resistance to bipolar fatigue, consistent with our earlier results.

Eye contact video-conferencing system and screen

Abstract: Our video-conferencing system (10) comprises stations (20, 30) which are remotely located from one another and interconnected by a transmission system (12). Each station includes a camera (23, 33), a projector (21, 31), and a screen (22, 32), which is simultaneously translucent with respect to the projector and transparent with respect to the camera. The projector as well as the camera are placed behind and in line with the screen, thus allowing greater viewing reciprocity and eye-contact and projecting a stronger feeling of reality to the video-conferencing parties. Our screen includes segments which discriminates between projected light and light to be captured by the camera based upon polarization or angle.

Hybrid intra-cell TDMA/inter-cell CDMA for wireless networks

Abstract: In a cellular network, a multiple-access methodology and concomitant circuitry in which TDMA is used inside each cell and CDMA signals, having pulse shapes with low cross-correlations, are assigned to adjacent cells. For example, these pulses could be Direct-Sequence Spread-Spectrum pulses. Such a hybrid system combines the high intra-cell capacity of TDMA with the inter-cell and multipath interference rejection capabilities of CDMA.

Multitrees: enriching and reusing hierarchical structure

Abstract: This paper introduces multitrees, a new type of structure for representing information. Multitrees are a class of directed acyclic graphs (DAGs) with the unusual property that they have large easily identifiable substructures that are trees. These subtrees have a natural semantic interpretation providing alternate hierarchical contexts for information, as well as providing a natural model for hierarchical reuse. The numerous trees found within multitrees also afford familiar, tree-based graphical interactions.

Interference suppression in cdma systems

Abstract: Circuitry and concomitant methodology for demodulating Direct-Sequence, Spread-Spectrum Code-Division Multiple-Access (DS/SS CDMA) channel signal using multiple samples per transmitted symbol and a minimum mean squared error criterion to suppress interference. In one embodiment, a bank of cyclically shifted filters (502) determined with reference to the conventional matched filter (401) for CDMA is used to demodulate the channel signal. In another embodiment, a bank of sub-filters (601, 602) determined with reference to the conventional matched filter (401) for CDMA is employed to demodulate the channel signal. In yet another embodiment, the output of a conventional matched filter is oversampled to demodulate the channel signal. Each embodiment utilizes a set of adaptive coefficients selected to minimize the mean square error between the transmitted symbol and detected symbol.

A Procurement Decision Support System in Business Volume Discount Environments

Abstract: Emergence of a new discount pricing schedule called Business Volume Discount becomes a major obstacle for procurement managers in finding the best purchasing strategy. In the context of business volume discount, a supplier offers discounts on total dollar amount of sales volume, not on the quantity or variety of the products purchased from the supplier. This paper describes a Procurement Decision Support System PDSS that has been successfully implemented to improve the purchasing activities of regional Bell telephone companies. In most purchasing operations, a flexible procurement plan is considered a necessity because of the uncertainties associated with product demand and procurement budget. PDSS provides this flexibility by combining two different purchasing strategies-purchasing on an annual commitment basis, and on an as-ordered basis. Although the development of the system is motivated by a particular application procurement of transmission plug-in in one of the regional telephone companies, the system is being used for a variety of procurement decisions involving business volume discount in the telecommunications industry. The results of the implementation indicate that cost savings of up to 15% are achieved. PDSS use is not limited to the companies in the telecommunications industry. The PDSS model is applicable to any organization having a centralized procurement operation with business volume discount.

Compatible licensed and unlicensed band portable handset unit for TDMA wireless communications system

Abstract: In a TDM/TDMA portable radio communications system, a portable handset is compatible for operation in both a frequency-division duplexing (FDD) mode for communication in the licensed portion of the Emerging Technologies frequency band, and in a time-division duplexing (TDD) mode for communication in the unlicensed portion of the Emerging Technologies frequency band. In the FDD mode, different frequencies are used to separate a downlink transmission to a portable from a port from an uplink transmission from a port to a portable. In the TDD mode, uplink and downlink transmissions are separated in different time-slots, but at the same frequency. The handset includes common transmit and receive circuitry that operates at fixed IF frequencies that are separated in frequency by the fixed FDD frequency difference between corresponding uplink and downlink signals. In the FDD mode, therefore, a frequency synthesizer (301), which is used to tune to transmit and receive at different frequencies from different ports, does not have to switch its frequency between transmitting and receiving a burst to and from a single port. In the TDD mode, however, even though uplink and downlink signals are at the same frequency, the synthesizer is switched in frequency between transmitting uplink and receiving downlink.

System and method for providing advanced intelligent network services

Abstract: In a telephone network, customized advanced intelligent network (AIN) services are provided to standard IN/1 '800' service customers. An IN/1 service switching point (IN/1 SSP) (130) receives a call directed to the standard IN/1 '800' service customer (112), and generates an '800' query to an '800' services data base (156). An '800' service control point ('800' SCP) (150) generates an '800' response containing a carrier identification code, and the IN/1 SSP routes the call via a trunk group designated by the carrier identification code. An AIN-equipped service switching point (AIN SSP) (126) then generates an AIN query to an AIN service data base (174). In response, an AIN-equipped service control point (AIN.SCP) (170) executes AIN service records corresponding to the standar IN/1 '800' service customer to generate an AIN response containing call processing instructions. The AIN SSP (126) then uses the call processing instructions to complete the call.

Space Variant Image Processing

Abstract: This paper describes a graph-based approach to image processing, intended for use with images obtained from sensors having space variant sampling grids. The connectivity graph (CG) is presented as a fundamental framework for posing image operations in any kind of space variant sensor. Partially motivated by the observation that human vision is strongly space variant, a number of research groups have been experimenting with space variant sensors. Such systems cover wide solid angles yet maintain high acuity in their central regions. Implementation of space variant systems pose at least two outstanding problems. First, such a system must be active, in order to utilize its high acuity region; second, there are significant image processing problems introduced by the non-uniform pixel size, shape and connectivity. Familiar image processing operations such as connected components, convolution, template matching, and even image translation, take on new and different forms when defined on space variant images. The present paper provides a general method for space variant image processing, based on a connectivity graph which represents the neighbor-relations in an arbitrarily structured sensor. We illustrate this approach with the following applications: (1) Connected components is reduced to its graph theoretic counterpart. We illustrate this on a logmap sensor, which possesses a difficult topology due to the branch cut associated with the complex logarithm function. (2) We show how to write local image operators in the connectivity graph that are independent of the sensor geometry. (3) We relate the connectivity graph to pyramids over irregular tessalations, and implement a local binarization operator in a 2-level pyramid. (4) Finally, we expand the connectivity graph into a structure we call a transformation graph, which represents the effects of geometric transformations in space variant image sensors. Using the transformation graph, we define an efficient algorithm for matching in the logmap images and solve the template matching problem for space variant images. Because of the very small number of pixels typical of logarithmic structured space variant arrays, the connectivity graph approach to image processing is suitable for real-time implementation, and provides a generic solution to a wide range of image processing applications with space variant sensors.

Broadband intelligent telecommunications network and method providing enhanced capabilities for customer premises equipment

Abstract: A Broadband Intelligent Network employs an ATM fast-packet (51) switch to route signaling cells from a calling party (52) to a switch port (53) directly connected to a network controller (64). The signaling cells carry a service request for download of a program module or data from a network resource unit (63) to the calling party, or for download of a program module or data from the calling party apparatus to a network host resource unit, or for service circuit service to the calling party or in a connection path between the calling party and a called party, or for a message broadcast. The network controller (64) responds to the information in the signaling cells and establishes the necessary switched virtual connections in the ATM switch (51) to provide the requested services. A service creation program (31) may be downloaded to the customer from the network (61), und used by the customer to create a new service script which is subsequently downloaded to the network for execution.

Identification and Role of Two-Photon Excited States in a π -Conjugated Polymer

Abstract: We have measured the full two-photon absorption (TPA) spectrum in the transparency range of single-crystal polydiacetylene paratoluene-sulfonate (PTS) using $z$ scan. The spectrum consists of three well-defined two-photon excited states superimposed on a continuum of even-parity states. Comparison of the TPA and the one-photon absorption spectra identifies a two-photon accessible state as the lowest excited state of PTS. The accompanying dispersion in the intensity-dependent refractive index coefficient ${n}_{2}$ is also reported.

Methods and apparatus for managing information on activities of an enterprise

Abstract: A system for maintaining various information representative of activities of an enterprise having four components. The first component creates the information including project data, subproject data, task data, and employee data. The second component stores the project data, the subproject data, the task data, and the employee data. The third component creates non-hierarchical relationship keys among the project data, the subproject data, the task data, and the employee data stored by the storing means; and the fourth component updates the project data, the subproject data, the task data, and the employee data stored by the storing means and for updating the relationship keys among the project elements, the subproject elements, the task elements, and the employee elements.

Self-regulating multiwavelength optical amplifier module for scalable lightwave communications systems

Abstract: In a multiwavelength lightwave communications system automatic self-power regulation on a channel-by-channel basis is achieved with a cascade of multiwavelength amplifier modules (200), wherein each multiwavelength amplifier module in the cascade includes a plurality of pump-shared parallel fiber amplifiers (208) operated in gain-saturation and connected between an optical demultiplexer (203) and multiplexer (209). An optional first gain stage (202) improves performance with higher optical signal-to-noise ratio. By self-regulating the power in each channel, the communications system is scalable, allowing the system to grow without deleterious effects due to power spread.