Patents Assigned to Telecom
  • Patent number: 5953385
    Abstract: In order to detect the error on the frequency of an M-PSK phase-modulated carrier, the phase .psi.(n) of the samples is restored to the interval ?-.pi., +.pi.?; .phi.(n)=mod(.psi.(n), 2.pi./M) is calculated; d(n)=mod(.phi.(n)-.phi.(n-1), 2.pi./M) is calculated; p'(n)=mod(d(n)+p(n-1), 2.pi./M) is calculated, where p(n)=mod(p*(n), 2.pi./M), where p*(n) is obtained by subtracting the current output from p'(n); d'(n)=p'(n)-p(n-1) is calculated; a parameter "tri" is defined by tri=1 if .vertline.d'(n).vertline.<S and tri=.beta. if .vertline.d'(n).vertline..gtoreq.S, where S is a threshold; det.sub.-- tri(n)=.alpha..p'(n).tri is calculated, det.sub.-- tri(n) constituting the current output, representative of the error on the frequency of the carrier.
    Type: Grant
    Filed: September 22, 1997
    Date of Patent: September 14, 1999
    Assignee: France Telecom
    Inventors: Ivar Mortensen, Marie-Laure Boucheret, Henri Favaro, Eric Belis
  • Patent number: 5952945
    Abstract: Method and apparatus of converting between digital and analogue signal formats, wherein dither signals are combined with information signals to be converted, the dither signals being as a predetermined plurality of particular discrete frequencies that are outside desired information signal bandwidth and have orderly relation including to signal conversion sampling rate, which orderly relation aids looping of sequences of patterns in a related data stream having pattern-to-pattern transitions similar to within-pattern transitions. Specifically, discrete dither signal frequencies have integral relation with their minimum separation or spacing and with said sampling rate, the lowest frequency and the minimum frequency separation each being whole number divisors or submultiples of higher dither frequencies andor of the signal conversion rate.
    Type: Grant
    Filed: August 14, 1997
    Date of Patent: September 14, 1999
    Assignee: Northern Telecom Limited
    Inventors: Nicholas Hugh James Latham, Christopher John Reed, John McNicol
  • Patent number: 5952966
    Abstract: A communications antenna assembly is disclosed, suitable for use in fixed antenna multiple access systems, such as fixed wireless access schemes and satellite communication systems. Such systems have independent base station transmitters which, in the case of fixed wireless access schemes, may be subject to over capacity and/or obstructions between the subscriber and the base station and, in the case of non-geostationary satellite communication systems continuously move. The antenna is operable to communicate with at least one of two communication stations at each of two directions from the antenna assembly, said assembly comprising: a beamformer connected to the antenna and arranged to allow the antenna to provide at least two antenna beams, one substantially in each of the communication station directions are provided substantially simultaneously, such that in use the antenna assembly can communicate with the two communication stations. A corresponding system and method of use is also described.
    Type: Grant
    Filed: September 11, 1997
    Date of Patent: September 14, 1999
    Assignee: Northern Telecom Limited
    Inventor: Martin Stevens Smith
  • Patent number: 5953338
    Abstract: A system comprises a system control module and a plurality of interconnected asynchronous transfer mode switches the interconnected asynchronous transfer mode switches are interconnected with one another via at least one physical interface to form a network. The network is used to transfer various types of information. Each asynchronous transfer mode switch has a connection admission control module to determine whether a virtual connection, such a virtual path, virtual channel, or grouping of virtual paths, can be connected through that particular asynchronous transfer mode switch. The virtual connection is formed from one asynchronous transfer mode switch to at least one other asynchronous transfer mode switch via a link of the at least one physical interface. The system control module connects to at least one asynchronous transfer mode switch and determines whether the virtual connection can be created in the network.
    Type: Grant
    Filed: December 13, 1996
    Date of Patent: September 14, 1999
    Assignee: Northern Telecom Limited
    Inventors: Patrick S. Ma, Gregory S. Graham
  • Patent number: 5953670
    Abstract: A CATV distribution network provides an interface between a cellular communications base station and a plurality of mobile terminals. A head end signal processor disposed at a head end of the CATV network provides a first frequency conversion between a cellular communications radio frequency and the CATV network transmission frequency. A plurality of remote antenna drivers are disposed at the remote end of the CATV network and provide a second frequency conversion between the cellular communications radio frequency and the CATV network transmission frequency. Antennas coupled to the remote antenna drivers provide radio communications with the mobile terminals. The remote antenna drivers are arranged in groups, each group being operated in a simulcast manner. Dynamic range compression of the cellular communications traffic is provided on the upstream path between the mobile terminals and the base station.
    Type: Grant
    Filed: May 1, 1996
    Date of Patent: September 14, 1999
    Assignee: Northern Telecom Limited
    Inventor: Paul Newson
  • Patent number: 5950837
    Abstract: A shipping kit assembly is disclosed for use in transporting circuit packs installed in electronic bays. The assembly kit includes a pair of spaced, upper and lower channel members which, together with a vertical band strap received in and retained thereby, are adapted to secure and support a plurality of circuit packs which are installed in shelf units or sub-racks for shipping or transporting therein. The bottom channel member incorporates a supporting bracket at each end therefor for securing and locating an attached circuit pack in a predetermined location in the shelf unit or sub-rack. One or more horizontal band straps may be used to secure the packs against movement in the shelf unit.
    Type: Grant
    Filed: July 7, 1998
    Date of Patent: September 14, 1999
    Assignee: Northern Telecom Limited
    Inventor: Robert John Barber
  • Patent number: 5949778
    Abstract: An apparatus for routing a plurality of cells. The apparatus includes a plurality of inputs, wherein the plurality of cells are received at the inputs. Each of the cells contains routing information. The apparatus also includes a plurality of outputs, wherein the outputs are associated with a plurality of destinations such that each output corresponds to a destination within the plurality of destinations. The apparatus employs a routing means for routing the cells received by the inputs through the apparatus to the outputs using the routing information contained in the cells. The routing means includes a number of single path switching matrixes in which each single path switching matrix has a plurality of stages. A portion of the these stages are dilated such that two or more cells may be routed to the same destination.
    Type: Grant
    Filed: December 31, 1996
    Date of Patent: September 7, 1999
    Assignee: Northern Telecom Limited
    Inventors: Hosame Hassan Abu-Amara, Venkat Kotamarti
  • Patent number: 5949861
    Abstract: A system and method for extending the time period at which a facsimile response signal can be received before a time-out occurs without altering the underlying transmission protocol. The disclosed system and method determines a response time before which a response signal must be received by a transmitting facsimile station in order to avoid a time-out event. Before the response time arrives, the disclosed system and method generates and transmits a delay signal to the transmitting facsimile station which does not substantively interfere with ongoing communications. Instead, the delay signal causes the transmitting facsimile station to tickle an internal time-out counter which results in an extension of the response signal delay tolerance. Delay signal frames can be transmitted repeatedly to accommodate any desired time-out period.
    Type: Grant
    Filed: April 13, 1998
    Date of Patent: September 7, 1999
    Assignee: Northern Telecom Limited
    Inventors: Christina K. Chan, Hongsoon H. Kwon, Simon S. Lam, William A. Larson
  • Patent number: 5949379
    Abstract: A microwave antenna device on PCMCIA network cards for notebook computers includes; extended base, which is connected to input port of PCMCIA network card, has pivot acceptor symmetrically located on the outer side of extended base, T-shaped pivot which is capable of 180-degree rotation about the vertical axis, is then supported by pivot acceptor. Tunnel is inside pivot and extended base, in which HF (high frequency) transmitting wire from input port passes through up to the top of pivot. Plate which is capable of 90-degree rotation in both clockwise and counter-clockwise direction is hooked up on pivot. Plate which is capable of 90-degree rotation in both clockwise and counter-clockwise direction is hooked up on pivot. Plate or bar microwave antenna is capped on pivot and connected through HF transmitting wire. In accordance with the above description, plate microwave antenna has the advantage of foldable for transportation easy to setup, receiving angle optimisable and preventing from breaking design.
    Type: Grant
    Filed: January 12, 1998
    Date of Patent: September 7, 1999
    Assignee: Alpha Telecom Inc.
    Inventor: Jui-Lin Yang
  • Patent number: 5950137
    Abstract: A method, for use in a mobile communications system having a plurality of mobile stations (MS's) and a mobile subscriber information register (MSIR), provides a requesting MS with location information (LI) of a target MS. At a first step, a LI request signal, including a subscriber number assigned to the target MS, a service code representing a LI supplying service and a secret number, is received from the requesting MS. At a second step, it is checked whether the service code of the LI supplying service is included in the subscriber information of the target MS stored in the MSIR. At a third step, if the service code of the LI supplying service is included in the subscriber information of the target MS, it is checked whether the secret numbers included in the subscriber information of the target MS and the LI request signal are identical each other.
    Type: Grant
    Filed: September 16, 1997
    Date of Patent: September 7, 1999
    Assignee: Daewoo Telecom, Ltd.
    Inventor: Young-Je Kim
  • Patent number: 5949578
    Abstract: A reflective grating for the optical diffraction of light rays comprises k juxtaposed, grooved, plane sub-gratings, the planes of the sub-gratings being offset in terms of height with respect to one another along the normal to the plane of the reflective surface of the grooves, enabling the difference in optical path of the grating to be reduced to the difference in optical path between the two ends of a sub-grating.
    Type: Grant
    Filed: February 19, 1998
    Date of Patent: September 7, 1999
    Assignee: France Telecom
    Inventor: Bernard Sermage
  • Patent number: 5949560
    Abstract: An Optical Transmission System includes a monitor for outputting monitored data representative of the extent to which an optical signal is degraded by polarization mode dispersion. The monitor measures the degree of depolarization present in a sample of the optical signal derived from an optical tap, the depolarization being associated with polarization variation at the bit rate frequency of a signal data stream carried by the optical signal. The monitored data is used to control operation of the system to reroute the optical path taken by the optical signal in the event of a threshold level of polarization mode dispersion being exceeded. A transmitter of the optical signal may also be controlled to minimize polarization mode dispersion by varying the polarization state of the optical signal at launch so as to reduce the measured monitor data. The monitor functions during normal transmission of optical signals without the need for shutting down links of the system for measurement purposes.
    Type: Grant
    Filed: February 5, 1997
    Date of Patent: September 7, 1999
    Assignee: Northern Telecom Limited
    Inventors: Kim Byron Roberts, Alan Robinson, Richard Edward Epworth, Henry John Harvey
  • Patent number: 5949645
    Abstract: An electronic unit with a mother board carrier beneath a service carrier in a housing. The carriers are independently movable between retracted use positions and forward access positions for maintenance. Service components are hence of no hindrance when removing printed circuit boards from the mother board carrier. The mother board is horizontal with the primary surface facing upwards. This latter feature together with the orientation of other printed circuit boards and of the service components minimizes the frontal area of the unit and provides pathways for front-to-rear cooling air flow. A connector arrangement connects the two carriers together only when both carriers are in their retracted use positions. Flexible lengths of cable extending between the carriers together with attendant stowage and hindrance problems are thus avoided. A retaining bar structure is included which acts at multiple positions against daughter boards to hold them securely against vibration during transporting and also in use.
    Type: Grant
    Filed: April 23, 1998
    Date of Patent: September 7, 1999
    Assignee: Northern Telecom Limited
    Inventors: Farid H. Aziz, Hope E. Ring, Balwantrai V. Mistrv, J. Michele Low, Mark R. Harris
  • Patent number: 5950231
    Abstract: A memory manager arrangement for use within a memory comprises a memory management structure, a set of memory blocks in which data can be stored under the control of the management structure, and a stack of pointers to free memory blocks within the set of memory blocks. The memory management structure incorporates a first management pointer to the stack of pointers and a second management pointer to a first memory block in the stack whereby to provide automatic allocation of memory blocks on demand. The manager arrangement may be created by an an application prior to the running of that application.
    Type: Grant
    Filed: November 25, 1996
    Date of Patent: September 7, 1999
    Assignee: Northern Telecom Limited
    Inventor: John Nichol
  • Patent number: 5946313
    Abstract: The invention provides for a E-Mux and a method for encapsulating/segmenting ATM cells into/from an Ethernet frame at the boundary between an ATM and an Ethernet network. An Ethernet end-station on the E-Mux is addressed using multiple MAC level identifiers, which are dynamically assigned according to the ATM virtual circuits which terminate on that end station, and have only transitory significance on the Ethernet. A unique ATM OUI identifies the frames carrying ATM-traffic.
    Type: Grant
    Filed: March 20, 1997
    Date of Patent: August 31, 1999
    Assignee: Northern Telecom Limited
    Inventors: David Ian Allan, Liam M. Casey, Andre J. Robert
  • Patent number: 5946627
    Abstract: The present invention relates to a communication process in a radio communication system with mobile terminals, in conjunction with at least one fixed base station, using the radio interface standard CAI-CT2, in which during the establishment of a communication between a base station (10) and a mobile terminal (15), the base station supplies the mobile terminal (15) with a radio link reference, which is a function of the identity of said mobile terminal (15). This link reference enables another base station in the network to distinction a handover request from a private communication establishment request.
    Type: Grant
    Filed: February 20, 1996
    Date of Patent: August 31, 1999
    Assignee: France Telecom
    Inventors: Christophe Desseignes, Fran.cedilla.ois Despres
  • Patent number: 5946362
    Abstract: An apparatus for use in a synchronous transmission system, for detecting a failure of a clock signal, which comprises: a reference clock generator for generating a reference clock signal (RCS) in response to a reset signal issued by a system controller in the STS; and means for receiving a clock signal, the RCS issued by the reference clock signal generating means and the reset signal and for producing a failure signal for the received clock signal, wherein the failure represents a state of a clock in which the clock does not have a pulse for a predetermined time interval, the time interval being measured by using the RCS.
    Type: Grant
    Filed: September 10, 1997
    Date of Patent: August 31, 1999
    Assignee: Daewoo Telecom, Ltd.
    Inventor: Jae-Sul Ha
  • Patent number: 5945860
    Abstract: A CML/ECL clock phase shifter device provides a 360.degree. phase control range and, upon being provided with two CML clock signals related by a known phase difference, the device produces any desired phase in response to a control signal. The device uses a CMOS current switch which generates current signals having the amplitude adjustable with the control signal, which is a digital word. Differential pairs provide amplitude modulated current signals for the input clock and the variant of the input clock. Two MOS transmission networks selectively invert each amplitude modulated signal and sum the signals from each side on a load network. The phase control resolution is optimal over four quadrants for quadrature input clock signals.
    Type: Grant
    Filed: January 4, 1996
    Date of Patent: August 31, 1999
    Assignee: Northern Telecom Limited
    Inventors: Bernard Guay, Michael Altmann
  • Patent number: 5945261
    Abstract: A method of avoiding unwanted phase discontinuities between adjacent sections of a long Bragg grating written section-by-section in an optical fibre uses masks with alignment parts additional to their writing parts. Each alignment part is a replica of a portion of the writing part of the adjacent mask. Light of the same wavelength as used for writing grating sections excites stronger luminescence in regions of waveguide where there has been no irradiation induced raising of the refractive index than in regions where such index raising has occurred. Therefore, for such light directed through the alignment part of the mask and into the already-written previous section of the grating, the intensity of luminescent light propagating to an end of the waveguide varies according to how well or how badly the bright fringes produced by the mask register with the corresponding irradiated portions of the written Bragg grating.
    Type: Grant
    Filed: May 15, 1997
    Date of Patent: August 31, 1999
    Assignee: Northern Telecom Limited
    Inventor: Howard Neil Rourke
  • Patent number: 5946382
    Abstract: This button telephone equipment comprising a plurality of button telephone apparatus 2a-2m having a plurality of the public line button 23 and a display for displaying the sender's information, and an auto-exchange apparatus 1, this auto-exchange apparatus 1 detecting the operation of the public line button during displaying the incoming call or during displaying the holding on the ON-HOOK status, and extracting the communication line data with reference to the incoming call on the basis of the data corresponding to the public line button of the operated button telephone apparatus, and extracting the sender's telephone number on the basis of the extracted communication line data, and extracting the sender's name on the basis of the extracted sender's telephone number, and then displaying the sender's telephone number and the sender's name on the display 22 the operated button telephone apparatus.
    Type: Grant
    Filed: September 11, 1997
    Date of Patent: August 31, 1999
    Assignee: Hitachi Telecom Technologies, Ltd.
    Inventor: Yoshinobu Sugahara