Push-pull Patents (Class 455/332)
  • Patent number: 5539749
    Abstract: A method for merging data streams generated by a plurality of base stations in a cellular mobile radio telephone network upon receipt by each base station of a mobile unit signal transmitted by a mobile unit, wherein each base station routes the mobile unit signal in the form of a stream of data in blocks of data bits, each bit in each block having associated therewith a reliability value generated by its respective base station, the various streams of data generated by the base stations are received at a unification point, and a unified signal is generated out of the various base station streams of data in the form of a composite data stream by selecting each bit thereof from corresponding bits in the various base station streams of data.
    Type: Grant
    Filed: July 20, 1994
    Date of Patent: July 23, 1996
    Assignee: Siemens Aktiengesellschaft
    Inventor: Hermann-Josef Eul
  • Patent number: 5539923
    Abstract: A mobile telephone apparatus operates as follow: when an origination signal is transmitted from the mobile station, the base station of a wireless zone where the mobile station is not present communicates a connection possible signal to the base station in the zone where the mobile station is present, and the base station having a larger number of idle channels than that of the other base station is selected on priority basis independent on the signal intensity. Therefore, when the origination signal from the mobile station is received by a plurality of base stations, the base station having the receiving level larger than the required minimum receiving level and having the maximum number of idle channels is selected, and it is possible to reduce the origination loss rate relative to the conventional system.
    Type: Grant
    Filed: March 22, 1994
    Date of Patent: July 23, 1996
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Shinji Matsumoto
  • Patent number: 5539744
    Abstract: A telecommunications architecture using ATM based technology is disclosed that supports wireless communications. Some embodiments of the present invention may provide a mechanism for hand-off, which has fewer costs and restrictions than other hand-off schemes the in the prior art. In one embodiment a plurality of virtual circuit identifiers is created such that each is unambiquously associated with the others. The virtual circuit identifiers are then transmitted to a wireless terminal, via a first radio port. Subsequently, the wireless terminal transmits one of the virtual circuit identifiers to second radio port.
    Type: Grant
    Filed: February 28, 1995
    Date of Patent: July 23, 1996
    Assignee: AT&T Corp.
    Inventors: Helen Chu, Bharat T. Doshi, Subrahmanyam Dravida, Sanjiv Nanda, Anil S. Sawkar, Kazem A. Sohraby
  • Patent number: 5537679
    Abstract: A communication network (10) includes a constellation (12) of mobile satellites (14) in low earth orbits and stationary gateways (24) near the surface of the earth. Data packets are routed through the network (10) using communication paths that change from moment to moment due to satellite movement. The routing paths are scheduled in advance (58) in response to predictable orbital satellite movement. The constellation (12) is configured so that only a minor amount of overlap in radio range exists between adjacent satellites (14). Gateways (24) include multiple, spaced apart antennas (30) that may be used to acquire arriving satellites (14'). When a gateway (24) has trouble quickly acquiring an arriving satellite (14'), an exception handoff time may be substituted for the scheduled normal handoff time at the gateway (24), departing satellite (14), and arriving satellite (14') involved.
    Type: Grant
    Filed: August 1, 1994
    Date of Patent: July 16, 1996
    Assignee: Motorola, Inc.
    Inventors: Jeffrey S. Crosbie, David M. Baum, Michael W. Krutz
  • Patent number: 5535425
    Abstract: Channel switching control in a mobile telecommunication system of a multiple zone configuration provided with base stations of zones for engaging in radio communication with mobile stations and base station control equipment for controlling the base stations, wherein the base station control equipment performs priority processing on a request for channel switching due to deterioration of quality, in which there is little margin of time until the quality of service deteriorates below a predetermined level, when receiving a request for channel switching to a stronger field transferred from a mobile station through a base station and a request for channel switching due to deterioration of quality from a base station, thereby enabling channel switching able to ensure a predetermined quality of service.
    Type: Grant
    Filed: January 26, 1995
    Date of Patent: July 9, 1996
    Assignee: Fujitsu Limited
    Inventor: Keizo Watanabe
  • Patent number: 5530910
    Abstract: The handover method disclosed relates to a mobile communication system in which, based on the number of handovers in mobile units, the size of the radio zone to be assigned to a mobile unit is selected. The mobile switching center measures the number of handovers in each of the mobile units engaging in communication and, during the handover in the mobile unit, the handover target radio zone is assigned based on the measured value of the number of handovers. The target handover of mobile units is determined by the target determination controller based the number of handovers memorized in the handover number recorder. The assignment of the appropriate size radio zone prevents an excess load on the mobile switching center and the capacity to accommodate subscribers in the mobile communication system is enhanced.
    Type: Grant
    Filed: December 27, 1994
    Date of Patent: June 25, 1996
    Assignee: NEC Corporation
    Inventor: Masanori Taketsugu
  • Patent number: 5530912
    Abstract: A method is disclosed for reducing handover failure probability in cellular networks which includes the steps of determining whether a mobile subscriber is traversing a pre-handover zone defined in each cell of the network, reserving a free channel in an adjacent cell for the mobile subscriber traversing the pre-handover zone, and granting the free channel to the mobile subscriber upon entering a handover region extending across the boundary of the adjacent cells provided that a free channel is available at such a time, and in the alternative, if a free channel is not available at such a time, the handover request is queued until a free channel becomes available.
    Type: Grant
    Filed: June 29, 1994
    Date of Patent: June 25, 1996
    Assignee: AT&T Corp.
    Inventors: Prathima Agrawal, Dinesh K. Anvekar, Balakrishnan Narendran
  • Patent number: 5530693
    Abstract: A packet data communication system (100) that includes a packet data routing network (101, 103) and a plurality of base sites (105-107) employs a method (400, 500) and apparatus for providing packet data to a communication unit (109). The packet data routing network (101, 103) provides a packet (201-208) of data to at least two of the base sites (105-107), one of the base sites (e.g., 105) being the site currently serving the communication unit (109) and the other base site or sites (e.g., 106, 107) being possible handoff targets. The serving base site (105) transmits at least a first portion (e.g., 201-203) of the packet (201-208) to the communication unit (109) and the communication unit (109) receives the transmitted packet or portion thereof. However, if during transmission of the packet (201-208) the communication unit (109) requires a handoff to one (e.g.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: June 25, 1996
    Inventors: Rod Averbuch, Israel A. Cimet, Valy Lev
  • Patent number: 5530917
    Abstract: A method for optimizing the use of channels, the changing of channels and handover procedures in a mobile telecommunications system for instance, wherein parameters belonging to the mobile telecommunications system generate the load values for the connections via different channels/base stations between subscribers in a public telephone network and mobile stations in the mobile telecommunications systems. Different kinds of parameters can be compared directly by means of the load values which are combined to provide a total load value for each connection. A first total load value is generated for a connection set-up between one of the subscribers and one of the mobile stations. The total load values for the connection are estimated for alternative channels/base stations and these total load values are compared with the first total load value. The system changes to the channel/base station that has the most favorable load value, on the basis of the comparison.
    Type: Grant
    Filed: May 17, 1994
    Date of Patent: June 25, 1996
    Assignee: Telefonaktiebolaget LM Ericsson
    Inventors: Claes H. Andersson, Knut M. Almgren, Kenneth Y. Wallstedt, Anna Fallgren, Hakan Eriksson
  • Patent number: 5526403
    Abstract: A wireline interface permitting a cellular telephone transceiver to originate and receive calls using both cellular and wireline services. The invention permits a subscriber unit to operate as a standard cellular telephone when it is disconnected from a land-based telephone line, and as both a full-featured telephone and a full-featured cellular telephone when it is connected to a wireline. A wireline interface circuit provides on/off hook, calling identification, and audio signal conversion functions on the wireline signals. A duplexed audio switch permits the audio signals provided to and from a cellular-type handset to be connected either to the cellular transceiver or to the wireline interface adapter, under control of the user. As a result, any handset-provided functions such as speed dialing or hands-free operation are available for use when operating on a wireline circuit as well as when operating on a cellular radio link.
    Type: Grant
    Filed: February 24, 1995
    Date of Patent: June 11, 1996
    Assignee: Novatel Communications Ltd.
    Inventor: Ambrose W.C. Tam
  • Patent number: 5524136
    Abstract: A method and apparatus for efficiently tracking the location of a mobile station in a cellular network, especially in cellular networks having nonuniform traffic distribution. A mobile station reports to a base station only upon entering selected reporting cells. When communication with a mobile station is desired, the station is searched for in the vicinity of the last reporting cell in which the station appeared. The vicinity of a reporting cell is defined as the set of all intersecting cells reachable from the reporting cell without passing through another reporting cell.
    Type: Grant
    Filed: April 20, 1992
    Date of Patent: June 4, 1996
    Assignee: International Business Machines Corporation
    Inventors: Amotz Bar-Noy, Ilan Kessler
  • Patent number: 5524009
    Abstract: In a wireless or cellular telephone system operated, for example, in accordance with the TIA/EIA IS-54 TDMA standard specification and frame structure, wherein RSS measurements in a Mobile Station of scanned communication channels are made in the slot intervals between the RX and TX slots to prepare for determining the gain (AGC) values needed in the receiver for a new channel identified over the current channel communicating with a Base Station, wherein slot interval measurements of the new channel signal strength are used to achieve a shorter handoff time in the Mobile Station and a more accurate initial AGC value in the receiver. The new channel signal strength is measured using the existing MAHO measurement procedure according to the IS-54 standard specification, or like procedure, and is performed in three slot intervals. The results of these measurements are used to determine the AGC value needed for the new radio channel.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: June 4, 1996
    Assignee: Nokia Mobile Phones Ltd.
    Inventors: Mika J. Tuutijarvi, Pertti Makikyro
  • Patent number: 5521962
    Abstract: Allowing multiple copies of authentication information for a mobile telephone to exist in switching nodes of a distributed switching system. The mobile telephone is only registered on one switching node at a time. One copy is maintained on the resident switching node, and another copy is maintained on the switching node on which the mobile telephone was last registered other than the resident switching node. If the mobile telephone normal only registers on the resident switching node and one other switching node, the authentication information is present on both switching nodes, and both always have the authentication information to register the mobile telephone stored internally which speeds up the registration process. Further, the authentication information does not have to be repeatly communicated through the distributed switching system.
    Type: Grant
    Filed: June 30, 1994
    Date of Patent: May 28, 1996
    Assignee: AT&T Corp.
    Inventor: David L. Chavez, Jr.
  • Patent number: 5521961
    Abstract: In a method of providing cellular telephone service to a mobile telephone located in an off-load cellular telephone system adjacent to a main cellular telephone system, the mobile telephone is registered with the off-load cellular telephone system upon the mobile telephone entering the off-load cellular telephone system, and then is registered with the main cellular telephone system as being located in the off-load cellular telephone system as a function of predetermined criteria. During the time in which the mobile telephone has entered the off-load cellular telephone system but has not yet registered with the main cellular telephone system as being located in the off-load cellular telephone system, rebroadcasting page signals from main cellular telephone system into the off-load cellular telephone system ensures delivery of incoming telephone calls to the mobile telephone.
    Type: Grant
    Filed: February 25, 1994
    Date of Patent: May 28, 1996
    Assignee: Celcore, Inc.
    Inventors: Anthony G. Fletcher, John L. Hatcher
  • Patent number: 5519758
    Abstract: In a radiotelephonic process for locating mobile subsribers, a profile is created from data recorded in a recording means in the form of a first work file and obtained during the movements of a particular mobile subscriber during a first predetermined observation period, the data relates to a plurality of daily chronological periods spanning the first observation period and each period has a start determined by the time at which the mobile subscriber entered a location zone with a particular daily identity, and an end determined by the time at which the mobile subscriber left the location zone and entered another location zone with a different identiy. There is also disclosed a radiotelephonic installation for carrying out the process.
    Type: Grant
    Filed: May 11, 1994
    Date of Patent: May 21, 1996
    Assignee: France Telecom
    Inventor: Sami Tabbane
  • Patent number: 5519761
    Abstract: The airborne radio communications system of the present invention enables an airborne radio to communicate with the ground based cellular radiotelephone system. The present invention also enables the ground based system to keep track of the location of the airborne radiotelephone and page it when a call from the ground based telephone system is received. The ground base station is connected to upward radiating antennas that form airborne cells. As the aircraft with the radio flies through the airborne cells, the airborne relay receives the signals from the base station and relays them to the radio. If the radio is transmitting signals, the relay transmits those signals, through the airborne cells, to the base station. As the aircraft moves from cell to cell, the radio is handed off to the next cell to maintain communications with the ground.
    Type: Grant
    Filed: July 8, 1994
    Date of Patent: May 21, 1996
    Assignee: QUALCOMM Incorporated
    Inventor: Klein S. Gilhousen
  • Patent number: 5517674
    Abstract: A method of controlling handoff in a telecommunications network is provided, the network including a land system and a plurality of mobile stations, the land system including a plurality of cells, the method comprising the steps of dividing each cell into a first region where evaluation of measurement values is performed and a second region where the evaluation of measurement values is not performed, performing an evaluation of measurement values when a mobile station enters the first region, and controlling the handoff based on the evaluation of measurement values.
    Type: Grant
    Filed: August 9, 1993
    Date of Patent: May 14, 1996
    Assignee: Telefonaktiebolaget LM Ericsson
    Inventor: Goren Rune
  • Patent number: 5517675
    Abstract: Transmission of candidate-sector signalling channels are synchronized to facilitate mobile-assisted handoff (MAHO) measurements by a mobile (125). Transmitters in candidate sectors each transmit their signalling channel at distinct frequencies and at predetermined intervals. The transmission of each signalling channel by each candidate sector transmitter is synchronized to provide a known reference to the mobile (125). When instructed, the mobile (125) need only to perform MAHO measurements at the predetermined intervals in the order and at the frequency instructed.
    Type: Grant
    Filed: February 13, 1995
    Date of Patent: May 14, 1996
    Assignee: Motorola, Inc.
    Inventors: James M. O'Connor, Eric R. Schorman, John D. Reed, Kamyar Rohani
  • Patent number: 5517673
    Abstract: A cellular radiotelephone system is accessed by a cellular radiotelephone without requiring System IDentification (SID) comparison during access. Access is performed by eliminating a rescan of Access Channels during access and using the Combined Paging and Access Channel which was identified during initialization for system access. Alternatively, the Access Channels may be rescanned upon an access request and a comparison of the Digital Color Code with the initially scanned channels is made. If the compared Digital Color Code matches, the identified channel is used for system access regardless of its SID.
    Type: Grant
    Filed: September 20, 1994
    Date of Patent: May 14, 1996
    Assignee: Ericsson Inc.
    Inventor: Michael D. Fehnel
  • Patent number: 5513380
    Abstract: In A speed-dependent hand over procedure for hierarchic cell structures, a check is carried out given a mobile station traveling into A radio coverage domain of a micro cell to see whether the radio coverage of the mobile station with respect to the micro cell has significantly or insignificantly improved within a time interval. In case of a significant improvement, the micro cell is blocked for the rapidly traveling mobile station.
    Type: Grant
    Filed: February 14, 1994
    Date of Patent: April 30, 1996
    Assignee: Siemens Aktiengesellschaft
    Inventors: Kolio Ivanov, Egon Schulz
  • Patent number: 5513246
    Abstract: In a cellular mobile radiotelephone system having a plurality of cells providing radio coverage by a plurality of base stations and having a plurality of mobile stations, the location of a mobile station with respect to cell boundaries is identified using measurements, performed at the mobile station or at selected cells, of transmissions from the cells or transmissions from the mobile station. When a cell is found that meets a specified standard with respect to a call connection in progress according to a first radio-signal criterion, a handoff candidate cell is selected according a second different radio-signal criterion. When no cell is found that meet the specified standard, a cell is selected according to the first radio-signal criterion. Handoff to the selected cell is attempted if that cell is not presently handling that call. More particularly, the first radio-signal criterion may be signal strength and the second radio-signal criterion may be path loss.
    Type: Grant
    Filed: November 12, 1991
    Date of Patent: April 30, 1996
    Assignee: Telefonaktiebolaget LM Ericsson
    Inventors: Sven-Olof L. Jonsson, Georg W. R. Chambert, Stig R. Bodin
  • Patent number: 5513379
    Abstract: A communications system and method of ordered borrowing which facilitates dynamic access to a global channel set that has been partitioned into subsets, with each cell of the system being assigned a particular subset of the channel set. The assignment of channel subsets is performed in such a way as to respect various constraints imposed by the physical layout. Calls originating in a cell are first assigned to the channels allocated to the base station of that cell, in an order determined by the cell. Once the allotted channels are exhausted, i.e. in the busy state, the cell attempts to borrow channels from those allotted to the base stations of neighboring cells in a specified order. The borrowing cell borrows a specified number of channels from each neighbor before returning to a particular cell to borrow additional channels. The channels borrowed from a neighbor are accessed in an order which is substantially the reverse of the order in which they are accessed by the owner cell.
    Type: Grant
    Filed: May 4, 1994
    Date of Patent: April 30, 1996
    Assignee: AT&T Corp.
    Inventors: Mathilde Benveniste, Albert G. Greenberg, Frank K. Hwang, Boris D. Lubachevsky, Paul E. Wright
  • Patent number: 5513247
    Abstract: The lack of uniformity for accessing wireless carriers to reach roaming wireless telephones prevents nationwide wireless telephone service from being provided in a seamless manner by an automated system that accesses the roamer access ports to connect a caller to a wireless telephone station in a manner such that the roaming nature of the called wireless telephone station is transparent to the caller. This problem is overcome, by a method for placing a telephone call to a wireless telephone station, method including the steps of: a) storing in a data base an association between respective (i) roamer access ports, (ii) mobile switching centers and (iii) one of a predetermined set of instructions, i.e.
    Type: Grant
    Filed: July 21, 1995
    Date of Patent: April 30, 1996
    Assignee: AT&T Corp.
    Inventors: Sandip Mukerjee, Ralph Utano
  • Patent number: 5509051
    Abstract: Each cell has an assigned classification that determines its inclusion in a measurement list for handing off. The candidate cells, which are selected from the measurement list are given priority level assignments. The priority levels are implemented by the candidate neighboring cells measured RF signal strength; and the order of handing off is arranged in accordance with the adjusted RF signal strength.
    Type: Grant
    Filed: September 9, 1993
    Date of Patent: April 16, 1996
    Assignee: Hughes Aircraft Company
    Inventors: Charles A. Barnett, Ashok D. Mehta, Lou King
  • Patent number: 5509052
    Abstract: A CT-2 base's intelligence (36) is enhanced by having a handset (12) transmit (418) its base registration history to the base station (24) such that the base can determine (724) whether the handset is correctly registered. The handset (12) requests (606) a link with any one of the previously registered base stations recorded in the base registration history by transmitting a link request containing the handset ID and any one of the previously recorded base IDs from the base registration history. This single base ID need not necessarily be the base station identification of the currently registered base station. The base station then determines (724) whether the one base station identification matches one member of the base registration history for the associated handset identification. In response to a match, the base transmits (712) the link grant to the handset.
    Type: Grant
    Filed: May 25, 1994
    Date of Patent: April 16, 1996
    Assignee: Motorola, Inc.
    Inventors: Song C. Chia, Simon M. L. Tsang
  • Patent number: 5509027
    Abstract: A method for a synchronizing user devices (12) performing handoffs includes providing a set of location synchronizing frequencies and data frequencies selected from a hopping set used by network access points (14). Each AP transmits synchronizing data (36) at the synchronizing frequencies during a portion of a short dwell (32), the short dwells (32) being interleaved between long dwells (30). When a user device (12) attempt a handoff, it tunes to at least one of the synchronizing frequencies and receives synchronizing information (36). The user device (12) then selects one AP (14) for link transfer and synchronizes its operation to the hopping set used by the selected AP (14).
    Type: Grant
    Filed: December 5, 1994
    Date of Patent: April 16, 1996
    Assignee: Motorola, Inc.
    Inventors: Frederick W. Vook, William K. Doss, Alan D. Muehlfeld, Mai T. Nguyen, John E. Shaver, Brian J. Wesselman
  • Patent number: 5509035
    Abstract: A method of mobile station synchronization to a system time, wherein the time alignment is attained while the mobile station operates in analog mode. The mobile stations transmits a periodic signal, each period of which has a leading edge. The base station detects the leading edge of the periodic signal and compares it to an indication of system time. The base station generates an error message for the mobile station indicating an update to the phase of the periodic signal. When the mobile station and the base station are time aligned, the base station may send a message indicating the absolute time at some future leading edge of the periodic signal thereby eliminating ambiguities of time due to the finite time required to receive the message.
    Type: Grant
    Filed: January 31, 1995
    Date of Patent: April 16, 1996
    Assignee: Qualcomm Incorporated
    Inventors: Edward G. Teidemann, Jr., Alejandro R. Holcman
  • Patent number: 5506869
    Abstract: In methods and apparatus for estimating carrier-to-interference ratios of signals transmitted between cellular radio base stations and mobile units, a SAT signal is transmitted from a base station to a mobile unit served by that base station. The mobile unit receives the SAT signal and retransmits the received SAT signal to the base station. A first order autoregressive parameter is calculated for the received SAT signal at the base station is correlated with a tabulated carrier-to-interference ratio estimate to estimate the carrier-to-interference ratio of the signals.
    Type: Grant
    Filed: October 27, 1994
    Date of Patent: April 9, 1996
    Assignee: Northern Telecom Limited
    Inventor: Claude Royer
  • Patent number: 5506837
    Abstract: Cellular mobile radio systems provide full-duplex communication between base stations and mobile stations and with the fixed public service network. Also known are trunked mobile radio systems wherein a group of mobile users can exchange information with each other in the half-duplex mode over a common channel, only one user transmitting to the others at any time. It has been proposed to provide mobile radio sets which are especially adapted to be switched for use in either of such systems. The present invention avoids the need for specific adaptation of a mobile radio set for that purpose. Instead, it enables a cellular mobile radio system to be selectively converted into a trunked mobile radio system by providing for the base station to couple an up-link radio channel of any mobile user to down-link radio channels of a selected group of mobile users. One or more such user groups can be formed, only one radio channel being used for each group.
    Type: Grant
    Filed: February 10, 1994
    Date of Patent: April 9, 1996
    Assignee: U.S. Philips Corporation
    Inventors: Michael Sollner, Alfons Eizenhofer
  • Patent number: 5504936
    Abstract: A cellular telephone system is described of the type wherein a plurality of contiguous cells, each having an assigned set of identification codes, are arranged with means for maintaining continuous communication with mobile telephones moving from cell to cell. The system allows multiple access by including means for assigning at least one of the in the assigned set of identification codes to more than one mobile telephone. A unique identification code is assigned to a mobile telephone located in the cell. A signal having a unique identification code is generated for identifying the mobile telephone. The signal is coupled to the zones. A combiner is also provided for combining signals from all of the zones in the cell. A receiver is coupled to the combiner for retrieving the signals having the code.
    Type: Grant
    Filed: June 21, 1994
    Date of Patent: April 2, 1996
    Assignee: AirTouch Communications of California
    Inventor: William C. Lee
  • Patent number: 5504803
    Abstract: A personal communications system permits a wireless handset to access either a cellular mobile telephone system (CMTS) or a private wireless telephone system (WTS) which shares the CMTS frequency band by utilizing those CMTS channels which are idle in the area serviced by the WTS. The wireless handset automatically selects between the WTS and CMTS operating modes by maintaining a list of previously accessed WTS control channels and periodically scanning that list for a WTS available at the location of the handset. If a WTS control channel is not found in that list, then the handset periodically scans all possible WTS control channels for the purpose of registering on an available WTS. If no WTS is found, then the handset switches to CMTS mode. The scanning methodology permits the wireless handset to rapidly lock on to an available WTS which will provide service to the handset, so as to reduce the possibility of the wireless handset missing incoming paging signals.
    Type: Grant
    Filed: August 2, 1993
    Date of Patent: April 2, 1996
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Jun Yamada, Kevin Callahan, Charles A. Jacobs
  • Patent number: 5504809
    Abstract: A communication system for use in a mine to provide two-way communication between a conveyance which moves in a mine and a communication network located in the mine. The system comprising: means for producing a signal indicative of the location of the conveyance in the mine; a plurality of repeaters situated in the mine and being coupled to the communication network; and a controller for controlling the repeaters and the controller being responsive to the signal and having means for activating the repeater which is proximate to the conveyance so that a communication link is provided between the conveyance and the communication network.
    Type: Grant
    Filed: September 3, 1993
    Date of Patent: April 2, 1996
    Assignee: Placer Dome Inc.
    Inventors: Frank Chalmers, Robert Millions
  • Patent number: 5504935
    Abstract: The invention concerns a mobile communication network (MCN) having communication paths (DCMRN, FBS, LE or ICMRN, RS, GCFN/GCRN, FBS, LE) between any one of mobile terminals (MT) and a fixed telecommunication network (FTN). Each communication path (DCMRN, FBS, LE or ICMRN, RS, GCFN/GCRN, FBS, LE) has a radio access link (DCMRN, ICMRN) between a mobile terminal (MT) and a relay station (RS) and has a relay link (GCFN/GCRN) between the relay station (RS) and a fixed base station (FBS). The mobile communication network has path selection means (FBS) for selecting, as part of a hand-over decision, a communication path (DCMRN, FBS, LE or ICMRN, RS, GCFN/GCRN, FBS, LE) between the mobile terminal (MT) and the fixed telecommunication network (FTN) based on measurement data of characteristics of radio access links (DCMRN/ICMRN) included in the possible communication paths (DCMRN, FBS, LE or ICMRN, RS, GCFN/GCRN, FBS, LE).
    Type: Grant
    Filed: March 8, 1994
    Date of Patent: April 2, 1996
    Assignee: Alcatel N.V.
    Inventor: Leo A. A. Vercauteren
  • Patent number: 5499387
    Abstract: The invention relates to a method in connection with handoff in a mobile radio communication system comprising at least one mobile station and a set of base stations surrounding the mobile station, each of the base stations including at least one traffic channel. Measured information that is significant for handoff-decisions and that before handoff of the mobile station from a first traffic channel to a second traffic channel has been measured, stored and associated with the first traffic channel, is associated with the second traffic channel in connection with handoff.
    Type: Grant
    Filed: May 23, 1994
    Date of Patent: March 12, 1996
    Assignee: Telefonaktiebolaget LM Ericsson
    Inventor: William R. G. Chambert
  • Patent number: 5499386
    Abstract: A multi-level layered cellular radio architecture serves mobile subscriber stations moving within the system. Best server selection is performed for the mobile stations by assigning within each cell a preference value to each other one of the cells with which is associated by proximity of service area. The strength of the radio signal received by the mobile from the serving cell as well as the radio channels of associated cells is measured. A decision as to the best serving cell for the mobile station is made based upon both the preference value of the associated cells and the signal strength of their respective radio channels.
    Type: Grant
    Filed: July 9, 1993
    Date of Patent: March 12, 1996
    Assignee: Telefonaktiebolaget L M Ericsson
    Inventor: Bror A. Karlsson
  • Patent number: 5497504
    Abstract: In a mobile communications network, cell-clusters are defined to include a multiplicity of cells. Wireless connections within the network are classified based on the actions taken for the connections when a radio congestion state is encountered. A cell-cluster controller controls admission of new calls to the cell-cluster, and admits or rejects the calls based on (1) number of existing calls of each class in the cell-cluster, (2) traffic characteristics including call holding time and a hand-off rate of each class, (3) quality-of-service (QOS) requirements of each class, and (4) policy for scheduling or sharing different call classes at each base station of the cell-cluster.
    Type: Grant
    Filed: May 13, 1994
    Date of Patent: March 5, 1996
    Assignee: The Trustees of Columbia University
    Inventors: Anthony S. Acampora, Mahmoud Naghshineh
  • Patent number: 5497424
    Abstract: A system for accessing a telephone system, in which a set of user stations are matched with a set of base stations for connection to a telephone network. Each base station may be coupled directly or indirectly to the telephone network and may be capable of initiating or receiving calls on the telephone network. Each user station may comprise a spread-spectrum transmitter or receiver and may be capable of dynamic connection to selected base stations. A plurality of base stations may be coupled to a private exchange telephone system for coupling user stations in calls outside the telephone network. User stations may use CDMA, FDMA, TDMA or other multiple-access techniques to obtain one or more clear communication paths to base stations. Base stations may be placed at convenient locations or may themselves be mobile. User stations may make and break connections with base stations as the user station moves between service regions, or is otherwise more advantageously serviced by, base stations.
    Type: Grant
    Filed: February 7, 1994
    Date of Patent: March 5, 1996
    Assignee: Omnipoint Data Company
    Inventor: Jeffrey S. Vanderpool
  • Patent number: 5497412
    Abstract: A system for enhanced call delivery to a roaming cellular subscriber, enabling said subscriber to receive calls placed to his MIN in his home system service area, utilizes a central telecommunications system processor capable of handling network applications, directly connected to a plurality of mobile telephone switches located in the service areas of a plurality of cellular telephone systems, each of said switches connected via a direct communication link to said central telecommunications system processor. A plurality of registers in said central telecommunications system processor are provided for storing data bases of system information, individual switch information, and subscriber information.
    Type: Grant
    Filed: April 7, 1994
    Date of Patent: March 5, 1996
    Assignee: GTE Telecommunication Services Incorporated
    Inventors: Margaret Lannen, Kenneth W. Hammer, Edward L. Didion
  • Patent number: 5493605
    Abstract: The present invention eliminates the need for non-audio communications performed between base units and handset units to identify the handset unit existing communication zones, and thereby reduces the consumption of handset unit batteries to extend the lives thereof. The cordless system telephone apparatus in accordance with the invention comprises a control unit connected to a public communication network through telephone lines, a plurality of base units connected to the control unit, and a plurality of handset units communicating with the base units by way of radio waves. In waiting states where the handset units are not in audio communication with the base units, the control unit does not carry out, through the communications with the base units, identifications or registrations of the communication zones in which the handset units exist. The switching of the base units for higher communication qualities is only conducted during audio communications.
    Type: Grant
    Filed: August 10, 1993
    Date of Patent: February 20, 1996
    Assignee: Uniden Corporation
    Inventors: Masaru Akiyama, Junji Kanjo
  • Patent number: 5493693
    Abstract: A mobile radio communication system is provided with a base station apparatus connected to a wire circuit, a mobile radio station apparatus which is connected to the base station apparatus by means of a radio circuit, a mode designation device for selecting either an analog mode or a digital mode when radio communication is to be performed between the base station apparatus and the mobile radio station apparatus, and a mode-informing device for informing the base station apparatus of the mode designated by the mode designation device.
    Type: Grant
    Filed: April 12, 1994
    Date of Patent: February 20, 1996
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masayuki Tanaka, Koichi Ito
  • Patent number: 5493563
    Abstract: A communication system utilizes rotated bursts of voice channels to implement mobile assisted handoff (MAHO). Mobile stations measure the voice channels of adjacent cells as hopping frequencies are rotated from frame-to-frame of the communication system. Measurement of the voice channels of adjacent cells can be performed by mobile stations during timeslots subsequent to their receive and transmission so that measurement during a timeslot dedicated to a control channel related to the adjacent cells is not necessary.
    Type: Grant
    Filed: July 26, 1993
    Date of Patent: February 20, 1996
    Assignee: Motorola, Inc.
    Inventors: Walt Rozanski, Kamyar Rohani
  • Patent number: 5491833
    Abstract: A method of selecting sector antenna which is capable of reducing interference and improving the efficiency of utilization of frequencies is applied to a mobile radio communication system wherein a plurality of sector antennas whose half-power beam widths are different from basically used normal sector antennas are used so as to cover the same areas in an overlapping state. A radio base station located within a corresponding zone covers a plurality of sector cells using the sector antennas provided for each of the corresponding sector cells. Further, some of the radio base stations employ a way to cover partial area overlapping a normal sector cell with a narrow sector cell using a sector antenna whose half-power beam width is small. Each radio base station has a predetermined constant according to the half-power beam width.
    Type: Grant
    Filed: December 20, 1994
    Date of Patent: February 13, 1996
    Assignee: NEC Corporation
    Inventor: Kojiro Hamabe
  • Patent number: 5491717
    Abstract: Transmission is controlled using the present method after a handoff procedure has been entered between a subscriber unit and target transceivers. During this process, a communication link between the subscriber and at least one other transceiver is maintained. A quality factor of a signal from the subscriber is received by the target transceiver. If the quality factor meets a quality threshold, then a transmission from the target transceiver is activated. If the target transceiver is active and the quality factor drops below the quality threshold, then the transmission from the target transceiver is terminated.
    Type: Grant
    Filed: October 18, 1993
    Date of Patent: February 13, 1996
    Assignee: Motorola, Inc.
    Inventor: Scott M. Hall
  • Patent number: 5491741
    Abstract: Base stations responding on a shared channel to a registration request message received on another shared channel from a wireless mobile unit with the base station to which the mobile unit is assigned transmitting in a first time slot and the other base stations transmitting in a time slot determined by the strength of the received signal from the mobile unit. If two base stations respond to the registration request message in the same time slot and the assigned base station does not respond, the mobile unit determines whether there is a response in a time slot which is earlier in time to the first time slot than the collided time slot. If the collided time slot is earlier in time than any other time slot in which a response is received, the mobile unit transmits a second registration request message specifying the collided time slot.
    Type: Grant
    Filed: October 23, 1992
    Date of Patent: February 13, 1996
    Assignee: AT&T Corp.
    Inventors: Charles Y. Farwell, Richard D. Miller, Richard A. Windhausen
  • Patent number: 5491834
    Abstract: An intelligent mobile radio unit is served by one of a network of macrocells and microcells.
    Type: Grant
    Filed: August 27, 1993
    Date of Patent: February 13, 1996
    Assignee: British Telecommunications public limited company
    Inventor: Si Tak S. Chia
  • Patent number: 5490137
    Abstract: A new frequency plan is allocated in a communication system by first comparing (30) the channels in the old frequency plan with the channels in the new frequency plan to identify any problem channels that may exist (31). The system then attempts to clear any problem channels by reassigning (14) mobile stations, that may be currently assigned to those problem channels, to channels common to the old and new frequency plans, first non-problem channels. The new frequency plan is then implemented (15) by activating any new channels that are not active under the old frequency plan and deactivating any old channels that are not a part of the new frequency plan and are not currently assigned. Any remaining mobile stations still assigned to problem channels are then reassigned (17) within the new frequency plan and the problem channels are then de-allocated.
    Type: Grant
    Filed: August 3, 1994
    Date of Patent: February 6, 1996
    Assignee: Motorola, Inc.
    Inventors: Thomas G. Hulsebosch, Bruce Duysen
  • Patent number: 5487174
    Abstract: The invention relates to methods for handling a bidirectional connection involving a mobile station in a cellular mobile radio communication system having adjacent cells of substantially different sizes, wherein the mobile station estimates the strength of radio signals received from base stations for cells of different sizes, the signal strength of radio signals received from the mobile station by base stations for cells of different sizes are estimated, decisions on which base station(s) should be responsible for an uplink channel of a bidirectional connection are based on uplink parameters including estimated strength for signals received at base stations, the signal strength at the base station(s) responsible for the uplink channel is used for controlling the output power of the mobile station, and decisions on which base station(s) should be responsible for the downlink channel of a bidirectional connection are based on downlink parameters including estimated strength of radio signals from base stations
    Type: Grant
    Filed: March 23, 1993
    Date of Patent: January 23, 1996
    Assignee: Telefonaktiebolaget LM Ericsson
    Inventor: Bengt Y. Persson
  • Patent number: 5487101
    Abstract: An off-load cellular system controls cellular service between a main cellular system and the off-load cellular system and provides off-load cellular service to a mobile telephone. The off-load cellular system includes a receiver circuit, monitoring and receiving an origination message broadcast from the mobile telephone located in the off-load cellular system, and a system controller, for receiving the origination message output from the receiver circuit, and for outputting a connect signal indicating whether the off-load cellular service is to be provided to the mobile telephone responsive to the origination message.
    Type: Grant
    Filed: March 26, 1993
    Date of Patent: January 23, 1996
    Assignee: Celcore, Inc.
    Inventor: Anthony G. Fletcher
  • Patent number: 5485462
    Abstract: The present invention encompasses a method of facilitating an audio source change in a digital radio communication system (100). A typical system includes a plurality of audio source units ( 101-103), a plurality of audio destination units (105, 106), and a switching unit (108) for rendering one of the plurality of audio source units (101-103) operable. Upon receipt (302) of an information-bearing frame from an audio source unit, a frame sequence value is identified (304). The expected frame sequence value is then determined (306), and this value is compared to the identified frame sequence value to determine whether or not the received frame sequence value matches the expected frame sequence value. When the frame sequence values match, it is assumed that the frames were sourced from the same audio source unit (i.e., no source change has occurred).
    Type: Grant
    Filed: August 25, 1994
    Date of Patent: January 16, 1996
    Inventors: David Helm, William Felderman
  • Patent number: 5483668
    Abstract: The soft handover of a channel or a base station according to the invention functions especially well in a TDMA system with a high TDMA milo. For the time of preparation of handover parallel physical links are formed between the mobile station (MS) and two or more base stations (BTS1, BTS2), whereby these base stations transmit the same signal to the mobile station (MS) in different time slots, and possibly in a different frequency.
    Type: Grant
    Filed: June 22, 1993
    Date of Patent: January 9, 1996
    Assignee: Nokia Mobile Phones Ltd.
    Inventors: Esa Malkamaki, Harri Jokinen