US Patent No: 4,718,081

Number of patents in Portfolio can not be more than 2000

Method and apparatus for reducing handoff errors in a cellular radio telephone communications system

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Abstract

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Wrong handoffs in a cellular radio telephone RF communications system can be minimized or eliminated without increasing locating receiver equipment requirements, field strength measurement time or system response time. Field strength measurements are made at handoff candidate cells and also at cells neighboring (geographically proximate to) those candidate cells. A weighted average of the measured field strength of the candidate cell and the field strength measured in cells neighboring the candidate cell is calculated for each candidate cell (the field strengths measured by neighboring cells may be multiplied by a weighting factor of 0.5). The weighted averages for the candidate cells are compared, and the candidate cell corresponding to the highest average is selected to handle the mobile transceiver call. Statistical analysis shows that this technique for determining handoff candidates significantly reduces the probability that a call will be handed off to a cell which is geographically distant from the mobile transceiver--even in the presence of propagation anomalies.

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Patent Owner(s)

Patent OwnerAddressTotal Patents
ERICSSON GE MOBILE COMMUNICATIONS INC.LYNCHBURG, VA375
GENERAL ELECTRIC COMPANYSCHENECTADY, NY31143

International Classification(s)

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Inventor(s)

Inventor Name Address # of filed Patents Total Citations
Brenig, Theodore Lynchburg, VA 3 177

Cited Art Landscape

Patent Info (Count) # Cites Year
 
MOTOROLA, INC. (4)
4,545,071 Portable radio for a zoned data communications system communicating message signals between portable radios and a host computer 35 1984
4,597,105 Data communications system having overlapping receiver coverage zones 64 1984
4,670,905 Method and apparatus for coordinating independent communications systems 74 1985
4,670,906 Data communications system transmitter selection method and apparatus 75 1986
 
Bell Telephone Laboratories, Incorporated (2)
4,384,362 Radio communication system using information derivation algorithm coloring for suppressing cochannel interference 41 1980
4,475,010 High density cellular mobile radio communications 184 1983
 
LUCENT TECHNOLOGIES INC. (1)
4,613,990 Radiotelephone transmission power control 267 1984
 
Nippon Electric Co., Ltd. (1)
4,435,840 Radio mobile communication system wherein probability of loss of calls is reduced without a surplus of base station equipment 61 1982

Patent Citation Ranking

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Patent Info (Count) # Cites Year
 
TELEFONAKTIEBOLAGET LM ERICSSON (PUBL) (25)
5,109,528 Handover method for mobile radio system 165 1989
5,175,867 Neighbor-assisted handoff in a cellular communications system 267 1991
5,434,798 Reconfiguration in a cellular communications network 37 1991
5,335,356 Adaptive resource allocation in a mobile telephone system 33 1991
5,293,641 Signal strength controlled directed retry in a mobile radiotelephone system 53 1991
5,513,246 Radiotelephone locating and handoff using alternative criteria 63 1991
5,287,545 Method of and apparatus for advanced directed retry 17 1991
5,408,696 Method and apparatus for correcting a radio signal strength information signal 3 1992
5,327,577 Handover method for mobile radio system 64 1993
5,517,674 Low capacity mobile assisted handoff in a cellular communications network 35 1993
RE36017 Cellular digital mobile radio system and method of transmitting information in a digital cellular mobile radio system 2 1993
5,737,689 Method for preventing calls of bad quality from being disconnected in a cellular mobile radio system 1 1994
5,778,316 Method and apparatus for selecting a control channel based on service availability 186 1995
5,970,407 Compensation for mobile assisted handoff measurement inaccuracies 13 1996
RE36078 Handover method for mobile radio system 11 1997
RE36079 Handover method for mobile radio system 1 1997
6,175,745 Initial transmit power determination in a radiocommunication system 56 1997
6,144,653 Method for communicating in a wireless communication system 140 1998
6,246,877 Method and system in a mobile radio system 6 1998
RE37685 Handover method for mobile radio system 1 1999
RE37787 Handover method for mobile radio system 2 1999
7,171,211 Estimating signal strength measurements in a telecommunications system 4 2002
8,060,091 Transfer rate measurements 2 2005
8,135,407 Network evaluated hard hardover using predictions 1 2005
8,185,115 Tracking cells for cell-reselection in a cellular communications system 0 2010
 
QUALCOMM INCORPORATED (17)
5,640,414 Mobile station assisted soft handoff in a CDMA cellular communications system 307 1994
6,914,965 Method and apparatus of providing a single state mobile unit in a modem connection comprising a wireless link 3 1994
6,157,668 Method and apparatus for reducing the average transmit power of a base station 54 1994
5,625,876 Method and apparatus for performing handoff between sectors of a common base station 144 1995
6,021,122 Method and apparatus for performing idle handoff in a multiple access communication system 40 1996
5,933,787 Method and apparatus for performing handoff between sectors of a common base station 71 1996
6,999,766 Method and apparatus for optimization of a cellular network 12 1997
5,864,760 Method and apparatus for reducing the average transmit power from a sectorized base station 48 1997
5,953,320 Method and apparatus for constructing a temporary list of neighboring base stations in a wireless communication device 31 1997
6,215,777 Method and apparatus for transmitting and receiving data multiplexed onto multiple code channels, frequencies and base stations 36 1997
6,674,736 Method and apparatus for performing idle handoff in a multiple access communication system 14 1999
7,876,729 Intersystem base station handover 16 2000
6,654,611 Method and apparatus for performing idle handoff in a multiple access communication system 3 2000
7,496,073 Method and apparatus for performing idle handoff in a multiple access communication system 1 2003
7,580,709 Method and apparatus for performing handoff in communications systems 1 2007
8,094,623 Method and apparatus for choosing a sector based on a scaled forward link metric 5 2007
8,010,113 Method and apparatus for performing handoff in communication systems 0 2009
 
MOTOROLA, INC. (8)
4,881,082 Antenna beam boundary detector for preliminary handoff determination 48 1988
5,038,399 Method for assigning channel reuse levels in a multi-level cellular system 151 1990
5,309,503 Dynamic channel assignment in a communication system 62 1991
5,740,530 Rapid received signal strength indication 5 1992
5,259,021 Transmission of interconnection information for next generation cordless telephone networks 10 1993
5,276,906 Radiotelephone system incorporating two thresholds for handoff 36 1993
5,379,447 Method of selecting a handoff target in a cellular communication system 45 1993
5,991,901 Indication of coverage area limits within digital communication systems 18 1994
 
MOTOROLA MOBILITY LLC (5)
5,497,383 Error detector circuit for receiver operative to receive discretely-encoded signals 14 1993
5,491,717 Method for controlling transmission during handoff in a communication system 40 1993
5,640,676 Method for generating a handoff candidate list 47 1995
6,337,983 Method for autonomous handoff in a wireless communication system 84 2001
6,725,043 Method for autonomous handoff in a wireless communication system 39 2001
 
GOOGLE INC. (4)
6,735,178 Method for maximizing throughput for multiple links using directional elements 35 2000
7,003,313 Method for enhancing mobility in a wireless mesh network 18 2001
6,999,441 Method and apparatus for contention management in a radio-based packet network 32 2001
7,068,630 Method for measuring load between MCDN devices for use in determining path with optimal throughput 1 2001
 
BROADCOM CORPORATION (3)
7,606,575 Remote radio data communication system with data rate switching 2 2002
7,787,419 System and method for providing a mesh network using a plurality of wireless access points (WAPs) 1 2003
7,672,674 Remote radio data communication system with data rate switching 3 2004
 
CANON KABUSHIKI KAISHA (2)
5,969,629 Wireless communication apparatus 3 1996
6,243,583 Communication system 19 1996
 
ERICSSON INC. (2)
5,995,498 Channel strength measurement shifting scheme 16 1996
6,801,778 Efficient location of mobile radiotelephones using cellular and GPS information 38 2001
 
HUGHES ELECTRONICS CORPORATION (2)
5,367,559 Sequential power estimation for cellular system handoff 30 1992
5,557,657 Handoff between overlay and underlay cells 46 1993
 
MITSUBISHI DENKI KABUSHIKI KAISHA (2)
5,067,171 Method and apparatus for hand-off of call in progress 26 1988
RE37669 Method and apparatus for hand-off of call in progress 5 1993
 
MOTOROLA MOBILITY, INC. (2)
5,390,339 Method and apparatus for selecting a serving transceiver 171 1991
5,428,818 Method and apparatus for reducing interference in a radio communication link of a cellular communication system 63 1994
 
NORTEL NETWORKS LIMITED (2)
5,293,642 Method of locating a mobile station 206 1990
6,049,715 Method and apparatus for evaluating a received signal in a wireless communication utilizing long and short term values 61 1997
 
SUN MICROSYSTEMS, INC. (2)
5,515,509 Method and apparatus for implementing self-organization in a wireless local area network 59 1995
6,360,264 Method and apparatus for maintaining connectivity of nodes in a wireless local area network 39 1995
 
ALCATEL (1)
6,493,555 Method of improving cooperation between entities during call handover 8 1998
 
AT&T Bell Laboratories (1)
5,384,826 Distributed packetized switching cellular radio telephone communication system with handoff 52 1993
 
AT&T CORP. (1)
5,371,780 Communications resource assignment in a wireless telecommunications system 162 1993
 
BELL ATLANTIC MOBILE SYSTEMS LLC (1)
5,613,204 Beacon system for roaming cellular stations 80 1994
 
BRITISH TELECOMMUNICATIONS PUBLIC LIMITED COMPANY (1)
5,379,446 Cellular radio with microcellular/macrocellular handoff 38 1993
 
CINTERION WIRELESS MODULES GMBH (1)
5,539,749 Method for merging data streams 26 1994
 
FRANCE TELECOM (1)
6,122,507 Call handover in a non-geostationary satellite constellation 6 1998
 
FREESCALE SEMICONDUCTOR, INC. (1)
5,603,112 Received signal strength indicator utilizing approximation factors and the I and Q signal components 8 1995
 
FUJITSU LIMITED (1)
7,328,019 Communication environment measurement method for mobile station and the mobile station 24 2005
 
INTERNATIONAL BUSINESS MACHINES CORPORATION (1)
5,390,234 Dynamic tracking of mobile stations in wireless networks 27 1992
 
LUCENT TECHNOLOGIES INC. (1)
5,884,174 Call admission control for wireless networks 51 1996
 
METRICOM, INC. (1)
7,050,806 Method for enhancing mobility in a wireless mesh network 11 2002
 
METROPCS WIRELESS, INC. (1)
5,586,338 System identification (SID) list for selecting operating frequencies 93 1994
 
MOTOROLA SOLUTIONS, INC. (1)
6,295,450 Method and apparatus for transferring communication within a communication system 39 1998
 
NEC CORPORATION (1)
4,989,204 High throughput communication method and system for a digital mobile station when crossing a zone boundary during a session 58 1989
 
NOKIA MOBILE PHONES INC. (1)
5,774,809 Simplified mobile assisted handoff of signal between cells 67 1996
 
PENNISULA ENGINEERING GROUP INC., (1)
5,187,806 Apparatus and method for expanding cellular system capacity 38 1990
 
STC PLC (1)
5,278,991 Handover techniques 46 1991
 
STEELHEAD LICENSING, LLC (1)
5,678,185 Mobile radio handover determination based on rise/fall of signal quality as a function of time 29 1995
 
TORSAL TECHNOLOGY GROUP LTD. LLC (1)
5,161,248 Method of predicting cell-to-cell hand-offs for a satellite cellular communications system 77 1989
 
U.S. PHILIPS CORPORATION (1)
5,189,734 Cellular radio system 77 1992
 
UNWIRED PLANET, LLC (1)
6,078,813 Handover quality control in a mobile communications system 9 1997
 
VERIZON PATENT AND LICENSING INC. (1)
5,761,618 Updating technique for downloading new system identification (SID) list into a handset 200 1994
 
Wellington Leisure Products, Inc. (1)
5,293,643 Method for handoff in a mobile radio communication system 24 1991
 
WI-LAN INC. (1)
6,647,053 Method and system for channel masking in a communication network 17 2000