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US5794149A Expired / Lapsed US ⏱️ 0.0 years remaining

Base station controlled handoff method and apparatus

Assignee: Nokia of America Corp
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Filing: 1995-12-29
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Granted: 1998-08-11
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Expires: 2015-12-29
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Abstract

Abstract A handoff method and apparatus are disclosed for use in a wireless communication network in which a base station servicing a call selects a handoff candidate base station based in part on subscriber-specific information. For example, in some wireless networks, certain subscribers can only access a limited number of base stations and the subscriber-specific information identifies such access limitations. A central control processor provides the subscriber-specific information to the base station servicing the call during the course of the call. The base station is then operable to select a handoff candidate from the one or more neighbor base stations based on one or more neighbor base station signal quality measurements and subscriber-specific information.

Inventors

  • 👤 John Hoo

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 04:00
CPC Classifications
H; H04; H04W; H04W36/00; H04W36/24; H04W36/30; H04W36/302; H04W36/34; H04W36/38

Claims Analysis

Total Claims: 33
Claim 1
Independent Claim 128 words
A base station for use in a wireless communication network including a switching center and one or more neighbor base stations, said switching center having access to subscriber-specific parameters and operable to generate subscriber-specific information therefrom, said base station comprising: a) a radio for communicating with a wireless terminal using radio signals; b) a circuit connected to the radio for converting radio signals to digital signals, said circuit operable to provide the digital signals to the switching center; c) a base station controller operable to select a handoff candidate from the one or more neighbor base stations based on one or more neighbor base station signal quality measurements and subscriber-specific information received from the switching center; and transmit a request signal to the handoff candidate requesting a handoff.
Claim 2
Dependent Claim 128 words
A base station for use in a wireless communication network including a switching center and one or more neighbor base stations, said switching center having access to subscriber-specific parameters and operable to generate subscriber-specific information therefrom, said base station comprising: a) a radio for communicating with a wireless terminal using radio signals; b) a circuit connected to the radio for converting radio signals to digital signals, said circuit operable to provide the digital signals to the switching center; c) a base station controller operable to select a handoff candidate from the one or more neighbor base stations based on one or more neighbor base station signal quality measurements and subscriber-specific information received from the switching center; and transmit a request signal to the handoff candidate requesting a handoff.
Claim 3
Dependent Claim 50 words
The base station of claim 1 wherein the base station controller is further operable to: transmit an information signal to the switching center after the handoff has occurred, the information signal containing information identifying the handoff candidate; and receive an update signal from the switching center containing updated subscriber-specific information.
Claim 4
Dependent Claim 51 words
The base station of claim 1 wherein the base station controller is further operable to select the handoff candidate based on subscriber-specific information, wherein the subscriber-specific information comprises a neighbor blocking list, said neighbor blocking list identifying those of the one or more neighbor base stations for which handoff is prohibited.
Claim 5
Dependent Claim 105 words
Base station of claim 3 wherein the base station controller is further operable to select from neighbor base stations the candidate handoff base station by: receiving from the wireless terminal a signal containing information representative of one or more signal quality measurements, the signal quality measurements corresponding to each of one or more neighbor base stations; determining whether there is an eligible handoff candidate, the eligible handoff candidate comprising one of the one or more neighbor base stations, said determination based in part on the signal quality measurements; and determining whether handoff is permitted to the eligible handoff candidate based on the neighbor blocking list.
Claim 6
Dependent Claim 32 words
The base station of claim 1 wherein the base station comprises a first face of a multiple-face base station and the handoff candidate comprises a second face of the multiple-face base station.
Claim 7
Dependent Claim 95 words
The base station of claim 3 wherein the radio is operable to communicate with the wireless terminal over a first radio channel, said first radio channel defined in part by a frequency band, and wherein the base station controller is operable to: receive a handoff acknowledgement signal from the handoff candidate indicating that the handoff candidate can communicate on a second radio channel, said second radio channel defmed in part by the frequency band; and transmit a handoff signal to the wireless terminal causing the wireless terminal to begin radio communications with the handoff candidate.
Claim 8
Dependent Claim 98 words
The base station of claim 1 wherein the radio is operable to communicate with the wireless terminal over a first radio channel, said first radio channel defmed in part by a frequency band, and wherein the base station controller is operable to: receive a handoff acknowledgement signal from the handoff candidate indicating that the handoff candidate has resources available to communicate on a second radio channel, said second radio channel defined in part by the frequency band; and transmit a handoff signal to the wireless terminal causing the wireless terminal to begin radio communications with the handoff candidate.
Claim 9
Dependent Claim 30 words
The base station of claim 1 wherein the base station controller is further operable to release control of the call after the handoff candidate begins communicating with the wireless terminal.
Claim 10
Dependent Claim 21 words
The base station of claim 1 wherein said radio communicates with the wireless terminal using code division multiple access ("CDMA") signals.
Claim 11
Dependent Claim 125 words
A switching center coupled to a plurality of base stations, each base station associated with one or more neighbor base stations, said switching center comprising: a) a digital control switch for receiving call signals from one or more base stations, the digital control switch operable to provide the call signals to a communications network; b) a central control processor that is operable to, upon notification of a base station status change for a call, generate a first list comprising neighbor base stations associated with one or more base stations servicing the call, generate from the first list a second list of subscriber ineligible neighbors based on subscriber-specific parameters, and provide an update signal containing data representative of the second list to a primary base station.
Claim 12
Dependent Claim 125 words
A switching center coupled to a plurality of base stations, each base station associated with one or more neighbor base stations, said switching center comprising: a) a digital control switch for receiving call signals from one or more base stations, the digital control switch operable to provide the call signals to a communications network; b) a central control processor that is operable to, upon notification of a base station status change for a call, generate a first list comprising neighbor base stations associated with one or more base stations servicing the call, generate from the first list a second list of subscriber ineligible neighbors based on subscriber-specific parameters, and provide an update signal containing data representative of the second list to a primary base station.
Claim 13
Dependent Claim 29 words
The switching center of claim 10 wherein the central control processor is further operable to provide said update signal to the primary base station within a handoff acknowledgement signal.
Claim 14
Dependent Claim 35 words
The switching center of claim 10 wherein the central control processor is operable to generate said first list and second list upon notification of a base station status change comprising an origination of the call.
Claim 15
Dependent Claim 29 words
The switching center of claim 12 wherein the central control processor is further operable to provide the update signal to the primary base station within a call attribute signal.
Claim 16
Dependent Claim 49 words
The switching center of claim 10 wherein the central control processor is operable to generate said first list and second list upon notification of a base station status change comprising a soft handoff, wherein said soft handoff includes an addition of a secondary base station to service the call.
Claim 17
Dependent Claim 28 words
The switching center of claim 14 the central control processor is further operable to provide the update signal to the primary base station within a handoff acknowledgement signal.
Claim 18
Dependent Claim 67 words
The switching center of claim 10 wherein said primary base station comprises a first face of a multi-face base station, and the central control processor is operable to generate said first list and second list upon notification of a base station status change comprising a softer handoff, wherein said softer handoff includes an addition of a second face of the multi-face base station to service the call.
Claim 19
Dependent Claim 32 words
The switching center of claim 16 the central control processor is further operable to provide the update signal to the first face of the multi-face base station within a handoff acknowledgement signal.
Claim 20
Dependent Claim 56 words
The switching center of claim 10 wherein the central control processor is operable to generate said first list and second list upon notification of a base station status change comprising a handoff wherein at least one base station is added to service the call and at least one base station is dropped from servicing the call.
Claim 21
Dependent Claim 31 words
The switching center of claim 10 wherein the central control processor is further operable to provide an update signal containing data representative of the first list to the primary base station.
Claim 22
Dependent Claim 90 words
The switching center of claim 10 wherein the central control processor is further operable to generate the second list of subscriber-ineligible neighbors from the first list of neighbor base stations by i) obtaining subscriber-specific parameters representative of one or more subscriber-specific features; ii) determining whether a first parameter of the one or more subscriber-specific parameters render a selected base station from the first list ineligible as a handoff candidate; and iii) repeating step ii) for a plurality of the base stations identified on the first list of neighbor base stations.
Claim 23
Dependent Claim 24 words
The switching center of claim 10 wherein said digital control switch is operable to receive call signals in the form of digital data packets.
Claim 24
Dependent Claim 41 words
The switching center of claim 10 wherein the digital control switch further comprises a speech handler, said speech handler operable to receive call signals associated with the call and convert the call signals into a format convertible with an external network.
Claim 25
Independent Claim 115 words
A method of performing a handoff during a call in a wireless communication system, the wireless communication system comprising a switching center, a first base station servicing the call prior to handoff, and a second base station, said method comprising: a) executing the handoff between the first base station and the second base station, wherein the second base station is added to service the call; b) notifying the switching center that the handoff has occurred; c) employing the central control processor to determine a list of neighbor base stations which are ineligible for a subsequent handoff; and d) forwarding the list to at least one base station servicing the call after execution of the handoff.
Claim 26
Independent Claim 115 words
A method of performing a handoff during a call in a wireless communication system, the wireless communication system comprising a switching center, a first base station servicing the call prior to handoff, and a second base station, said method comprising: a) executing the handoff between the first base station and the second base station, wherein the second base station is added to service the call; b) notifying the switching center that the handoff has occurred; c) employing the central control processor to determine a list of neighbor base stations which are ineligible for a subsequent handoff; and d) forwarding the list to at least one base station servicing the call after execution of the handoff.
Claim 27
Dependent Claim 33 words
The method of claim 23 wherein step c) further includes employing the central control processor to determine the list of neighbor base stations which are ineligible for a subsequent handoff using subscriber-specific parameters.
Claim 28
Dependent Claim 36 words
The method of claim 23 wherein step a) further includes executing a soft handoff between the first base station and the second base station and step d) further includes forwarding the list to first base station.
Claim 29
Dependent Claim 22 words
The method of claim 23 further including a step e) selecting a handoff candidate for a subsequent handoff based on the list.
Claim 30
Dependent Claim 50 words
The method of claim 23 wherein step c) further comprises first employing the central control processor to determine a first list of neighbor base stations associated with the call and then determining the list of neighbor base stations which are ineligible for a subsequent handoff based on the first list.
Claim 31
Dependent Claim 36 words
The method of claim 23 wherein step a) further includes executing a semisoft handoff between the first base station and second base station and step d) further includes forwarding the list to the second base station.
Claim 32
Dependent Claim 54 words
The method of claim 27 wherein step b) further comprises providing an information signal to the switching center after the handoff has occurred, the information signal containing information identifying the second base station; and wherein step c) further comprises determining the first list of neighbor base stations based in part on the information signal.
Claim 33
Dependent Claim 92 words
The method of claim 26 wherein step e) further comprises receiving from a wireless terminal associated with the call a signal containing information representative of one or more signal quality measurements, the signal quality measurements corresponding to each of one or more neighbor base stations; determining whether there is an eligible handoff candidate, the eligible handoff candidate comprising one of the one or more neighbor base stations, said determination based in part on the signal quality measurements; and determining whether handoff is permitted to the eligible handoff candidate based on the list.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2001-08-10 2002-02-09 2002-08-11 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2005-08-10 2006-02-09 2006-08-11 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2009-08-10 2010-02-09 2010-08-11 $7700.00 Window Closed / Lapsed

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