Abstract:
A method for using a verification system comprising a verification terminal (30, 32, or 34), operated by a verification authority, a remote terminal (20, 22, or 24), and a communication link coupling the terminals. The method includes generating a document data file from an identity document provided at the remote terminal, transmitting the document data file from the remote terminal to the verification terminal, generating a verification data file that verifies an attribute of the document at the verification terminal and preferably comprises a digitized signature of the verification authority, transmitting the verification data file to the remote terminal, and finally merging the document data file and the verification data file to produce a verification record. The verification record may be time stamped and stored and/or printed by a printer. Alternatively, the verification record may be assembled and stored at the verification terminal. The verification method is especially useful for the remote verification of identity documents required at a point of sale of a product or service, for example, banking services.
Abstract:
A method of and apparatus for balancing rotating machinery (20) involves the transient acquisition of transient data (100) over the operational speed range of the engine being analyzed. A spectrum of the transient data is acquired using a real time spectrum analyzer (7) capturing an RPM triggered waterfall (34, 38). Further, a computer calculates a one shot balance solution. The balance solution (44) is shown on a video display screen (850) and includes the suggested solution to the balance problem based on the acquired data and generic sensitivity coefficients (46) and the predicted vibrational behavior of the proposed solution. By acquiring a second set of data, it can be verified whether the one shot balance solution remedied the balance problem. If a problem remains, the operator may calculate engine specific sensitivity coefficients based on at least two previous data acquisition runs. A new trim balance solution is then calculated based on the immediately previous run and the calculated engine specific sensitivity coefficients.
Abstract:
A broadband communications system for coupling telephony (10) or other digital networks to a CATV network (12). The system transmits a multiplex of telephony signals in the forward band of the CATV network. Each forward channel is QPR modulated on a carrier and contains multiple subscriber telephony signals. The forward telephony channels are demodulated and multiplexed by a plurality of subscriber terminals into the individual telephony signals directed to an addressed subscriber. Audio and control signals returning from the subscriber are digitized into standard telephony signals and QPSK modulated on a carrier onto the reverse band of the CATV network. The multiplicity of reverse band telephony channels are demodulated and multiplexed into a standard telephony signal which is directly interfaced to the telephony network. The reverse band modulators are frequency agile and modulate telephony signals from a subscriber in a selected one or more frequency subbands in the reverse band of the subscription network.
Abstract:
A method for providing packet error indication (62) in a multi-hop communications system (10) in which packets (17) of data are transmitted from a transmission site (14) to a reception site (32) via a plurality of successive physical links (22a, 26a, 28a, 30a, 22b, 26b, 28b, 30b, 22c, 26c, 28c, 30c). At the transmission site, a pre-defined bit (62) in a packet (16) to be transmitted is set to a first value indicating that no errors are present in the packet. Then, at each successive physical link, after transmission of the packet over that link, the following steps are performed: detecting (82) whether any uncorrectable errors occurred in the packet during transmission over that link; if an uncorrectable error is detected, setting (90) the pre-defined bit in the packet to a second value indicative of an uncorrectable error in the data of the packet; and relaying (88) the packet to the next successive physical link for transmission over that next link. A decoder (32) at the reception site may, upon receiving a given packet, examine the value of the pre-defined bit to determine the integrity of the data contained in that packet.
Abstract:
A video system for processing compressed video data into composite data, the composite video data corresponding to a standard composite video signal type selected from a plurality of standard types including at least one of an NTSC composite video signal type and a PAL video signal type, including a processor (34), a standard video decompressor (32) and a video interface (40). The standard video decompressor processes the compressed video data into decompressed video data and user data, the user data having VBI data encoded therein. The processor culls the VBI data from the user data. The video interface processes the decompressed video data and the VBI data into a composite video signal. The video interface includes a VBI data generator (60) to process the VBI data into VBI signal, a mixer (50) coupled to the video decompressor to receive the decompressed video data, the mixer being coupled to the VBI data generator to receive the VBI signal and then output Y, U and V data.
Abstract:
A broadband communications system having means for coupling telephony (10) or other digital networks to a CTV network (12). The system includes transmitting a multiplex of telephony signals in 3 MHz channels in the forward band of the CTV network. Each 3 MHz channel is QPR modulated on a carrier and contains multiple subscriber telephony signals. The forward telephony channels are demodulated and demultiplexed by a plurality of subscriber terminals into the individual telephony signals directed to an addressed subscriber. The individually addressed telephony signal is then applied to a line card which connects the subscriber telephony equipment to the system. Audio and control signals returning from the subscriber are digitized into standard telephony signals and modulated on a carrier in 50 kHz reserved telephony channels onto the reverse band of the CTV network. The multiplicity of reverse band telephony channels are demodulated and multiplexed into a standard telephony signal which can be directly interfaced to the telephony network.
Abstract:
An apparatus providing a dynamic virtual service capability in a multi-service communications system is claimed. A dynamic virtual service comprises an associated group of basic services wherein only one of the basic services in the group is active at any time. Basic services comprise a number of service components which are transmitted to the apparatus on one or more of a plurality of different frequency channels. The apparatus comprises a service selection switch for selecting either one of the basic services directly or one of the dynamic virtual services. A dynamic virtual service map is provided that defines for each dynamic virtual service, on a time-varying basis, the currently active one of the group of basic services that comprises that dynamic virtual service. Means responsive to the service selection switch and to the dynamic virtual service map are provided for automatically selecting the currently active basic service of a subscriber selected dynamic virtual service. Finally, the apparatus provides means for receiving and accessing the service components of a selected basic service from the frequency channel carrying those components. According to one embodiment, dynamic virtual service map definitions are periodically retransmitted to the apparatus on each frequency channel carrying service components of one of the group of basic services that comprise that dynamic virtual service. Additionally, a "home" basic service may be defined for each dynamic virtual service. When a dynamic virtual service is initially selected by a subscriber, the apparatus initially "tunes" to the frequency channel carrying the service component of that home basic service.
Abstract:
A method of selecting individual subscribers for inclusion in groups by means of certain selection criteria comprises the steps of storing criteria related to terminals of a subscription television system, defining criteria which characterizes a group, logically linking the criteria in a predetermined manner to form a group criteria definition statement, comparing the stored terminal criteria with the group criteria definition statement, and assigning an individual or group of terminals to the group when the stored terminal criteria matches the group criteria definition statement. The selection criteria, for example, may include a range of terminal serial numbers, a range of terminal addresses, the status of the terminal, the service codes for the terminal and subscriber terminal features. The logical operators may include logical AND, logical OR, logical NOT, equal to, greater han, less than, parentheticals for joining operators and brackets and separators for service codes.
Abstract:
A method of data transmission for a cable television system comprises the steps of transmitting data via a plurality of signals including, but not limited to, in-band audio, in-band video and out-of-band signals. The in-band data signals are transmitted on scrambled or non-scrambled channels. In in-band video data transmission, the method comprises the further steps of selecting certain lines of the vertical blanking interval for in-band video data transmission, omitting certain equalizing pulses during the selected lines and inserting in-band video data during the selected lines. The several data signals, in-band and out-of-band, have compatible transaction formats to facilitate decoding and data storage processes at a subscriber terminal (300) of the cable television system. Data transmission apparatus (100) comprises a data inserter (107a) for inserting in-band data in non-scrambled channels, an addressable data transmitter (140) for transmitting out-of-band and a scrambler (104) for inserting data in scrambled channels.
Abstract:
An optical communications system provides optical signals of different wavelengths over an optical fiber (1, 2) having a zero dispersion wavelength. Electrical dispersion compensating elements (36-39) independently compensate optical signals having wavelengths different than the zero dispersion wavelength for dispersion in the optical fiber. Limiting radio frequency signals for modulating a light emitting device or laser (21-24) outputting signals at a wavelength different than the zero dispersion wavelength to less than one octave of frequency permits second order harmonic distortion resulting from dispersion in the fiber to be filtered at a receiving location. The optical communications system may include a reverse transmission path.