Other

Alcatel Canada Inc.

Mpr Teltech Ltd.

Alcatel Networks Corporation

Sound Qa Solutions Inc.

Sentry Telecom Systems Inc.

Neil B Cox

Edwin L Froese

Randy A Law

Kent Graham Bodell

James Lawrence Booth

Svetlana Brzev

Bill McEwen

Diane Kennedy

Cameron Young

A method and apparatus for determining the compressive strength of masonry units based on airborne sonic signals generated by stimulating the samples with short duration, mechanical impulses are described. The non-destructive testing apparatus consists of a specimen support unit which mechanically isolates the masonry unit from the environment and from the support, a mechanical stimulator, and an acoustic response detector. The signals recorded are analyzed to extract the pertinent features which are then used to compute the compressive strength of the sample. The pertinent signals are deduced through a calibration of the masonry type being analyzed (material and shape) based on physical analysis of the sample's normal modes of vibration, or through Finite Element Analysis of the vibrations, or through direct empirical calibration. This non-destructive testing method is low-cost, readily implemented and provides a reliable technique for compressive strength estimation.

Method and apparatus for non-destructive measurement of modulus of elasticity and/or the compressive strength of masonry samples

This invention allows enterprises to achieve specific objectives in the management and enforcement of policies related to the use of telecommunications services. It was conceived for use in connection with traditional telephone networks that carry voice, facsimile or voice-band-data (VBD) traffic, though it is not necessarily limited to such networks. It involves measurement of the properties of traffic on a communications channel, and the use of such knowledge in combination with various ancillary properties of telecommunications service usage to guide the conditional performance of prescribed actions based on user-defined policies. The measured traffic properties include classification of the type of traffic, where the set of possible classes include zero or more classes selected from a group of general categories comprising Voice, Facsimile, Voice-Band-Data, DTMF, Audible Network Signaling, Facsimile Handshaking, Voice-Band-Data Handshaking, Silence and Unknown. The ancillary properties may include network control parameters such as the apparent on-hook and off-hook state of the communications channel, the calling number, the called number, the side of the channel that originated the call, the side of the channel that is the dominant source of traffic for the call, the elapsed time since a call starts, and the time or day. The prescribed actions may include imposition of a recorded voice message, blockage of traffic on the communications channel, forced call termination through intervention with network signaling, direct notification of security personnel, generation of alarms, generation of call detail records, or other actions. The prescribed actions may also involve selecting or configuring a downstream telecommunications service for carriage of traffic with the observed traffic properties.

Apparatus and method for management of policies on the usage of telecommunications services

A method of minimizing throughput delay in constant-bit-rate services carried over packet-based networks subject to variable delays, comprises, in one embodiment, the steps of receiving incoming packets in a buffer, reading out bits from the buffer at a clock frequency fi, continually monitoring the buffer fill level L , determining the maximum fill level Lmax over a plurality of successive samples, determining the minimum fill level Lmin over a plurality of successive samples, adjusting the clock frequency f to cause the maximum fill level Lmax to tend toward a target value TargetLmax, and adaptively changing said target value TargetLmax so that the minimum fill level Lmin tends toward a predetermined set-point. The rate of change of the target value TargetLmax is significantly slower than the rate of adjustment of clock frequency. The invention can be applied to other types of clock recovery.

Delay minimization for circuit emulation over packet switched (ATM) networks

A method of clock recovery from a fast packet switched asynchronous network wherein a time stamp is transmitted over a network that has variable delay, involves maintaining an input counter at a sending device. The counter has a value dependent on an input clock. The value of the input counter is periodically transmitted over the network to a receiving device. A local counter at a receiving device has a value dependent on a local clock. The received value sample x.sub.i is compared with the local sample y.sub.i to derive the difference e.sub.i. The local clock frequency f.sub.j is adjusted such that the average of Emin.sub.j, where Emin.sub.j is the minimum of a block of error samples e.sub.i, remains close to a predetermined value, preferably zero. The clock recovery method is particularly suitable for MPEG2 video transmitted over ATM.

Clock recovery for video communication over ATM network

An apparatus and method is disclosed for performing policing functions for specialized telephone services, and for mitigating fraudulent usage of such services in ubiquitous telephone networks that carry voice, facsimile or voice-band-data traffic. Signal processing is used to determine the properties of traffic present on a channel at a given point in time, and actions are conditionally imposed based on such traffic properties. A first embodiment of the invention can be applied to prevent fraudulent use of telephone services through suppression of an answer supervision response. A second embodiment of the invention can also be applied for regulation of access to specialized telephone services which depend on the manner of customers' use of such services.

Fraud prevention apparatus and method for performing policing functions

A method and apparatus for detecting and classifying signals that are the additive combination of a few constant-amplitude sinusoidal components, herein called N-tones. The attributes of this method and apparatus include provision of superior classification performance with an algorithm of low computational complexity. The method includes filtering to remove extraneous signal components, separation of the incoming signal into one or more output streams and segmenting these output streams into blocks of successive data samples. The magnitude of the data within each block is estimated along with the frequencies of the dominant spectral components. The frequency estimates are then used as part of the configuration process of a set of notch filters for removal of the identified dominant spectral components. The newly-configured notch filters are then applied to the same data blocks and the magnitudes of their outputs are estimated. The estimated magnitudes from before and after the notch filtering are then passed on to a block classifier along with the aforementioned frequency estimates. This block classifier tests its inputs to ascertain if the input signal conforms to prespecified conditions of tonal purity, absolute component magnitude, relative component magnitude and component frequency. Finally, a timing classifier is applied to monitor the time course of block classifications and test the candidate N-tones for conformance with application-specific requirements regarding signal persistence and longevity.

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Burnaby, Canada

Neil B Cox