Abstract: Advantageous error rate performance, high bandwidth efficiency, low delay and reduced error floor are achieved at an acceptable level of decoding complexity via the use of serial concatenated turbo codes. These are codes for which at least some of the output bits, including at least one redundant bit, provided by a first, outer encoder are, after interleaving, further processed by a second, inner encoder. The resulting data and redundant bits then select a symbol from a predetermined constellation for transmission. In the receiver, the turbo code is decoded using a corresponding number of soft output decoders which operates iteratively in such a way that improved performance as compared to a single encoding can be achieved. The turbo codes can be of various dimensionalities and can be used as a component of a multilevel code to achieve a desired level of bandwidth efficiency.

Abstract: A path-oriented approach is provided to determine surviving paths in a decoder. The paths that are retained as the surviving paths are some number, M, of the paths which have the smallest path metrics, even if two or more of those paths come into a given state. This approach provides significantly improved performance in at least those applications in which branch metrics are a function of the surviving path from which the branch emanates.

Abstract: In a method of administering a telephone local loop plant, a substantial portion--preferably at or above 80%--of the existing narrowband plant is caused to be "dedicated," so that constituent segments of an existing local loop therewithin are not allowed to be used to form other local loops when the existing loop is taken out of service. The remainder of the narrowband plant--the "non-dedicated" plant--is used to fill subscriber current orders for new service. Administration of the narrowband plant that has been dedicated is given over to an administrative system that is deployed to administer broadband facilities within the local loop plant. In preferred embodiment, the local loop plant is upgraded from narrowband to broadband in a way which gives priority to those geographical areas for which the costs of maintaining the narrowband plant are the greatest. The method, overall, provides a mechanism for reducing the costs associated with administering all of the narrowband plant using the legacy systems.

Abstract: A logical data architecture for fetch-intensive database applications includes a first and a second logical database. The second database includes materialized views over the first database. Updates are propagated from the first database to the second database using so-called view maintenance techniques. In preferred embodiments, the first database may be optimized for update transactions and the second database may be optimized for read transactions. At least one of the materialized views included in the second database is based on a pre-defined application read transaction. The update processing overhead associated with view maintenance is substantially performed at the first database.

Abstract: A method and apparatus for determining whether a wireless station is operating within a prescribed geographic location. During an initialization process, the wireless telephone measures propagation delays of pilot signals from nearby base stations and stores the propagation delays in a non-volatile memory of the wireless station. Thereafter, during a check process, the wireless station measures propagation delays of pilot signals from nearby base stations and compares them with the stored propagation delays stored in memory. If the difference between the two sets of propagation delays are within a predetermined tolerance, then a determination is made that the wireless station is operating within the prescribed geographic location. Multiple sets of propagation delays may be stored in memory such that a determination can be made as to whether the mobile station is operating within any one of a number of prescribed geographic locations.

Abstract: Signal points from a PCM-derived constellation are selected for transmission via a modulation technique which employs different levels of redundancy coding--including the possibility of no redundancy coding--for respective different sub-constellations of the overall PCM-derived constellation. The coding that is employed for at least one of the sub-constellations is carried out independently from any coding that is employed for any of the other sub-constellations. In preferred embodiments, the sub-constellations are non-overlapping portions of the overall PCM-derived constellation, the redundancy codes are trellis codes, and the trellis codes employed in conjunction with sub-constellations having increasingly smaller minimum distance between signal points provide respectively increasing amounts of decibel gain in that minimum distance in order to compensate for that increasingly smaller minimum distance.

Abstract: A method and apparatus for the three dimensional graphical display of information. Information is displayed as nodes and arcs connecting nodes. The nodes and arcs are displayed with their three dimensional characteristics used to encode data attributes. In one embodiment, the nodes and arcs represent geographic network data and are displayed on a representation of a globe. The height of the arcs above or below the surface of the globe encodes a link attribute of the data, while the height of the nodes above or below the surface of the globe encodes a node attribute of the data. Three dimensional characteristics of the nodes and arcs other than height may also be used to encode data attributes. In addition, the three dimensional representation of the data allows for novel thresholding techniques, such as drawing certain nodes and arcs below the surface of the globe and using the globe as a clipping surface.

Abstract: Techniques for fault-tolerant computing which do not require fault-tolerant hardware or a fault-tolerant operating system. The techniques employ a monitor daemon which is implemented as one or more user processes and a fault-tolerant library which can be bound into application programs. A user process which is executing on ordinary hardware under an ordinary operating system is made fault tolerant by registering it with the monitor daemon. The degree of fault tolerance can be controlled by means of the fault-tolerant library. Included in the fault-tolerant library is a function which defines portions of a user process's memory as critical memory, a function which copies the critical memory to persistent storage, and a function which restores the critical memory from persistent storage. The monitor daemon monitors fault-tolerant processes, and when such a process hangs or crashes, the daemon restarts it.

Abstract: A method and apparatus for determining the location of a mobile telephone within the serving area of a mobile telephone system are disclosed. A mobile switching center analyzes the calling mobile telephone number and called telephone number to determine if a location function is required. Upon initiation of the location function by the mobile switching center, a mobile location module calculates a location estimate of the mobile telephone. The mobile location module receives a list of signal strengths received by the mobile telephone from cell site antennas within the serving area. The distance between the mobile telephone and a plurality of cell site antennas is calculated using a technique which reduces the error component of the calculated distances. These reduced error distances are used to geometrically determine an estimate of the location area within the sewing area of a mobile telephone system.

Abstract: Software rejuvenation techniques which improve reliability of a software system by stopping execution of the system and restarting the execution with "clean" state. The rejuvenation techniques are generally available to applications executing in a computer system. The techniques are implemented using a daemon process which observes applications registered with it and restarts them if they crash or hang and a process like the cron process of the UNIX operating system. The daemon process responds to a rejuvenation specification which indicates that an application which is registerd with it be rejuvenated by making a script for the cron process which specifies that the application's process be killed. When the cron process executes the script and kills the application, the daemon process observes that the application is dead and restarts it. In restarting the application, the daemon process may use state previously saved by the application for that purpose.

Abstract: A method for deadlock recovery in a shared resource multiprocess message passing computer system. The processes executing in the computer system perform periodic local checkpoints and communicate via inter-process messages. Upon detection of a deadlock in the computer system, inter-process rollback dependency is analyzed in order to choose a resource to reclaim. The choice of a resource to reclaim is made such that a resource manager which manages the resource can be rolled back so as to reclaim the resource, and such that an application process which is waiting for the resource is not rolled back past the point at which deadlock was detected. Thus, upon system restart, the reclaimed resource can be provided to the waiting process, and the waiting process can execute past the deadlock point.

Abstract: An antenna for use in urban areas and the like, wherein the antenna is of a design that can be attached to the exterior corner of a building. The antenna is designed to be a low-profile configuration and conformal so as to maximize the aesthetic quality. The antenna also has a continuous backplane so as to create a radiation pattern that will allow substantially complete coverage of an intersection that is adjacent to the location of the antenna.

Abstract: Disclosed is a method for error recovery in a multiprocessing computer system of the type in which each of the processes periodically takes checkpoints. In the event of a failure, a process can be rolled back to a prior checkpoint, and execution can continue from the checkpointed state. A monitor process monitors the execution of the processes. Upon the occurrence of a failure, a target set of checkpoints is identified, and the maximum consistent global checkpoint, which includes the target set of checkpoints, is computed. Each of the processes is rolled back to an associated checkpoint in the consistent global checkpoint. Upon a subsequent occurrence of the same failure, a second set of checkpoints is identified, and the minimum consistent global checkpoint, which includes the target set of checkpoints, is computed. Each of the processes is rolled back to an associated checkpoint in the consistent global checkpoint.

Abstract: A method and apparatus for querying a disjunctive database is disclosed. An annotated object, which defines a complete object which is a unique element of the normal form of the database, is stored and maintained in memory. A complete object is created using the annotated object, and is stored in memory. A query is run against the complete object. If continued processing is required, a next function produces a next annotated object, which represents another unique element of the normal form of the database. The next annotated object is stored in memory, overwriting the previous annotated object. A complete object is then created using the next annotated object and is stored in memory, overwriting the previous complete object. The query is then applied to the complete object stored in memory. By processing the elements of the normal form one at a time and reusing memory spaces, the present invention has a polynomial space requirement.

Abstract: A pay per use system for of the unauthorized use of computer software. An encryption program encodes original software to produce secured software. The encoding is accomplished by using cryptographic techniques. In order to use the software, a user must call a telephone number to receive the cryptographic keys necessary to decrypt the secured software. Thus, users must pay for each use of the secured software. The system allows software developers to freely distribute the secured software. Copies of the secured software may be freely made, because payment is based on each use of the software not on each copy of the software.

Abstract: Apparatus and methods for determining whether a word/sense pair is proper for a context. Wide contexts (100 words) are employed for both training and testing, and testing is done by adding the weights of vocabulary words from the context. The weights are determined by Bayesian techniques which interpolate between the probability of occurrence of a vocabulary word in a conditional sample of the training text and the probability of its occurrence in the entire training text. A further improvement in testing takes advantage of the fact that a word is generally used in only a single sense in a single discourse. Also disclosed are automated training techniques including training on bilingual bodies of text and training using categories from Roget's Thesaurus.

Abstract: In a speaker verification system, a method of compensating for differences in speech samples obtained during registration and those obtained during verification due to the use of different types of microphones is provided by filtering at least one of the samples such that the similarities of the two samples are increased. The filtered sample is used within the speaker verification matching process. A two-way comparison is disclosed in which both a verification speech sample and a reference sample are filtered with nonlinear microphone characteristics such as carbon microphone characteristics. A four-way comparison is also disclosed in which patterns produced from unfiltered verification and reference samples and patterns produced from the filtered verification and reference samples are compared to identify a match. A score is determined for each comparison. The comparison having the best score is used to determine if a match has occurred.

Abstract: A first portion of an optical fiber encapsulant is selectively removed by softening it; i.e., converting the first portion from a solid state to a partly fluid state, as by exposure to an appropriate chemical. The first portion (12) is then penetrated with at least first and second knife edges (14, 15), the penetration being on opposite sides of the optical fiber (10). The first portion of the encapsulant is removed from the optical fiber by providing relative movement between the knife edges and the optical fiber, the movement being in the direction of the central axis of the fiber, thereby to gather at least part of the first portion of the encapsulant on the knife edges. In a preferred embodiment, third and fourth knife edges (16, 17) the also included on opposite sides of the optical fiber.

Abstract: A failure rate independent system for achieving zero defect data integrity in a computer transaction system is disclosed. The system receives events from an event generator and stores the raw events to disk. Structural information relating events to transactions is not stored on disk. Data which is lost after a system failure is reconstructed from the raw events during recovery. Transaction processing capacity is increased by trading off the continual updating of disk stored events and associated structural information for the post recovery reconstruction of structural information. As a result, zero defect data integrity is achieved at minimum processing cost.