US6038448A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wireless communication system having hand-off based upon relative pilot signal strengths
Assignee: Ericsson AB
•
Filing: 1997-07-23
•
Granted: 2000-03-14
•
Expires: 2017-07-23
Abstract
Abstract A wireless communication system facilitates wireless communication with a mobile unit within a respective service area. The wireless communication system includes a mobile switching center and a plurality of base stations. Each base station couples to the mobile switching center and provides wireless communication within a respective cell or within a plurality of respective sectors. Each base station provides a pilot signal that may be received by the wireless mobile unit. With multiple sectors, a pilot signal is provided for each sector. The mobile unit may wirelessly connect to any of the base stations' cells and sectors. A determination of whether to be connected to a particular base station cell and/or base station sector is based upon the relative strengths of pilot signals received by the wireless mobile unit. The mobile unit may evaluate the relative strengths of received pilot signals and simply request a connection to a base station or a disconnection therefrom based upon the evaluation. However, the mobile unit may also notify the mobile switching center of strengths of received pilot signals with the mobile switching center taking action. In such case, the mobile switching center may determine thresholds and pass the thresholds to the mobile unit for later use, the thresholds based upon the relative strengths of the pilot signals. A corresponding method includes steps for operating a wireless communication system.
Inventors
- 👤 Ashvin H. Chheda
- 👤 Ahmad Jalali
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 16:48
CPC Classifications
H; H04; H04W; H04W36/00; H04W36/24; H04W36/30; H04W36/302; H04W16/00; H04W16/24
Claims Analysis
Total Claims: 45
Claim 1
Independent Claim
153 words
A wireless communication system that facilitates wireless communication with a mobile unit operating within a respective service area, the wireless communication system comprising: a mobile switching center; a plurality of base stations, each base station coupled to the mobile switching center, each base station providing wireless communication and each base station providing a pilot signal that may be received by the wireless mobile unit; the mobile unit receiving a plurality of pilot signals from the plurality of base stations and measuring the strength of the received pilot signals, the received pilot signals including a strongest pilot signal and at least one weaker pilot signal; the mobile unit wirelessly connected to at least one of the base stations; and a determination of whether to be connected to a particular base station corresponding to a weaker pilot signal based upon the difference in strength between the strongest pilot signal and the corresponding weaker pilot signal.
Claim 2
Dependent Claim
153 words
A wireless communication system that facilitates wireless communication with a mobile unit operating within a respective service area, the wireless communication system comprising: a mobile switching center; a plurality of base stations, each base station coupled to the mobile switching center, each base station providing wireless communication and each base station providing a pilot signal that may be received by the wireless mobile unit; the mobile unit receiving a plurality of pilot signals from the plurality of base stations and measuring the strength of the received pilot signals, the received pilot signals including a strongest pilot signal and at least one weaker pilot signal; the mobile unit wirelessly connected to at least one of the base stations; and a determination of whether to be connected to a particular base station corresponding to a weaker pilot signal based upon the difference in strength between the strongest pilot signal and the corresponding weaker pilot signal.
Claim 3
Dependent Claim
30 words
The wireless communication system of claim 1, the mobile unit evaluating the relative strengths of received pilot signals and requesting a connection to a base station based upon the evaluation.
Claim 4
Dependent Claim
33 words
The wireless communication system of claim 2, the mobile unit evaluating the relative strengths of received pilot signals and requesting a release from a connection to a base station based upon the evaluation.
Claim 5
Dependent Claim
45 words
The wireless communication system of claim 1, wherein: the mobile unit notifies the mobile switching center of strengths of received pilot signals; and the mobile switching center determines whether to establish connections between base stations corresponding to the received pilot signals and the mobile unit.
Claim 6
Dependent Claim
45 words
The wireless communication system of claim 4, wherein the mobile switching center determines whether to remove a connection between the mobile unit and one of the plurality of base stations based upon strengths of the weaker pilot signals as compared to the strongest pilot signal.
Claim 7
Dependent Claim
35 words
The wireless communication system of claim 1, wherein the mobile unit determines whether to notify the mobile switching center of the strengths of received pilot signals based upon strengths of the pilot signals and thresholds.
Claim 8
Dependent Claim
57 words
The wireless communication system of claim 1, wherein: a connect threshold level is determined based upon strengths of pilot signals received by the mobile unit; and the determination of whether to initiate a connection to a particular base station is made based upon a comparison of the strength of a respective pilot signal to the connect threshold.
Claim 9
Dependent Claim
60 words
The wireless communication system of claim 1, wherein: a connect threshold level is determined based upon a number of base stations to which the mobile unit is connected; and the determination of whether to initiate a connection to a particular base station is made based upon a comparison of the strength of a respective pilot signal to the connect threshold.
Claim 10
Dependent Claim
61 words
The wireless communication system of claim 1, wherein: a connect threshold level is determined by the mobile unit based upon strengths of pilot signals received by the mobile unit; and the determination of whether to initiate a connection to a particular base station is made based upon a comparison of the strength of a respective pilot signal to the connect threshold.
Claim 11
Dependent Claim
33 words
The wireless communication system of claim 9, wherein: the connect threshold level is determined based upon relative strengths of pilot signals received by the mobile unit from at least one connected base station.
Claim 12
Dependent Claim
60 words
The wireless communication system of claim 1, wherein: a drop threshold level is determined based upon strengths of pilot signals received by the mobile unit; and a determination of whether to initiate a drop of a connection with a particular base station is made based upon a comparison of the strength of a respective pilot signal to the drop threshold.
Claim 13
Dependent Claim
40 words
The wireless communication system of claim 11, wherein: the drop threshold level is determined for a particular connected base station based upon strengths of pilot signals received by the mobile unit from at least some of the connected base stations.
Claim 14
Dependent Claim
157 words
The wireless communication system of claim 1, wherein: each of the base stations includes a plurality of sectors, wherein the base station may communicate with mobile units in more than one of the plurality of sectors and wherein the base station provides a pilot signal for each sector that may be received by the wireless mobile unit; the mobile unit receiving a plurality of pilot signals from the plurality of sectors of the base station and measuring the strength of the received pilot signals, the received pilot signals including a strongest pilot signal and at least one weaker pilot signal; the mobile unit connected to a particular sector of the base station corresponding to the strongest pilot signal; and a determination of whether to be connected to a particular sector of the base station corresponding to a weaker pilot signal based upon the difference in strength between the strongest pilot signal and the corresponding weaker pilot signal.
Claim 15
Dependent Claim
178 words
A wireless communication system that facilitates wireless communication with a mobile unit operating within a respective service area, the wireless communication system comprising: a base station that provides wireless communication within a plurality of sectors that form the service area, wherein the base station may communicate with the mobile unit in more than one of the plurality of sectors and wherein the base station provides a pilot signal for each sector that may be received by the wireless mobile unit; the mobile unit receiving a plurality of pilot signals from the plurality of sectors of the base station and measuring the strength of the received pilot signals, the received pilot signals including a strongest pilot signal and a plurality of weaker pilot signals; the mobile unit wirelessly connected to at least one of the sectors of the base station; and a determination of whether to be connected to a particular sector of the base station corresponding to a weaker pilot signal based upon the difference in strength between the strongest pilot signal and the corresponding weaker pilot signal.
Claim 16
Dependent Claim
178 words
A wireless communication system that facilitates wireless communication with a mobile unit operating within a respective service area, the wireless communication system comprising: a base station that provides wireless communication within a plurality of sectors that form the service area, wherein the base station may communicate with the mobile unit in more than one of the plurality of sectors and wherein the base station provides a pilot signal for each sector that may be received by the wireless mobile unit; the mobile unit receiving a plurality of pilot signals from the plurality of sectors of the base station and measuring the strength of the received pilot signals, the received pilot signals including a strongest pilot signal and a plurality of weaker pilot signals; the mobile unit wirelessly connected to at least one of the sectors of the base station; and a determination of whether to be connected to a particular sector of the base station corresponding to a weaker pilot signal based upon the difference in strength between the strongest pilot signal and the corresponding weaker pilot signal.
Claim 17
Dependent Claim
33 words
The wireless communication system of claim 14, the mobile unit evaluating the relative strengths of received pilot signals and requesting a connection to a sector of the base station based upon the evaluation.
Claim 18
Dependent Claim
36 words
The wireless communication system of claim 14, the mobile unit evaluating the relative strengths of received pilot signals and requesting a release from a connection to a sector of the base station based upon the evaluation.
Claim 19
Dependent Claim
45 words
The wireless communication system of claim 14, wherein: the mobile unit notifies the base station of strengths of received pilot signals; and the base station determines whether to establish a connection between the mobile unit and one of the of sectors of the base stations.
Claim 20
Dependent Claim
44 words
The wireless communication system of claim 14, wherein the mobile unit notifies the base station of strengths of received pilot signals; and the base station determines whether to drop a connection between the mobile unit and one of the sectors of the base station.
Claim 21
Dependent Claim
40 words
The wireless communication system of claim 14, wherein the mobile unit determines whether to notify the base station of the strengths of received pilot signals based upon strengths of the pilot signals received from the base station and determined thresholds.
Claim 22
Dependent Claim
58 words
The wireless communication system of claim 14, wherein: a connect threshold level is determined based upon relative strengths of pilot signals received by the mobile unit; and the determination of whether to initiate a connection to a particular base station is made based upon a comparison of the strength of a respective pilot signal to the connect threshold.
Claim 23
Dependent Claim
33 words
The wireless communication system of claim 20, wherein: the connect threshold level is determined based upon relative strengths of pilot signals received by the mobile unit from connected sectors of the base stations.
Claim 24
Dependent Claim
64 words
The wireless communication system of claim 14, wherein: a drop threshold level is determined based upon relative strengths of pilot signals received by the mobile unit; and a determination of whether to initiate a drop of a connection with a particular sector of the base station is made based upon a comparison of the strength of a respective pilot signal to the drop threshold.
Claim 25
Dependent Claim
54 words
The wireless communication system of claim 22, wherein: the drop threshold level is determined for a particular connected sector of the base station based upon relative strengths of a strongest pilot signal and weaker pilot signals received by the mobile unit corresponding to at least one of the connected sectors of the base stations.
Claim 26
Independent Claim
118 words
A method of operating a wireless communication system that facilitates wireless communication with a mobile unit operating within a respective service area, the method comprising: broadcasting a plurality of pilot signals, each of pilot signals corresponding to a respective one of a plurality of base stations; receiving, by the mobile unit, a plurality of received pilot signals; measuring strengths of the received pilot signals, the received pilot signals including a strongest pilot signal and at least one weaker pilot signal; and determining whether to establish a connection between the mobile unit and a base station corresponding to a weaker pilot signal based upon the difference in strength between the strongest pilot signal and the corresponding weaker pilot signal.
Claim 27
Independent Claim
118 words
A method of operating a wireless communication system that facilitates wireless communication with a mobile unit operating within a respective service area, the method comprising: broadcasting a plurality of pilot signals, each of pilot signals corresponding to a respective one of a plurality of base stations; receiving, by the mobile unit, a plurality of received pilot signals; measuring strengths of the received pilot signals, the received pilot signals including a strongest pilot signal and at least one weaker pilot signal; and determining whether to establish a connection between the mobile unit and a base station corresponding to a weaker pilot signal based upon the difference in strength between the strongest pilot signal and the corresponding weaker pilot signal.
Claim 28
Dependent Claim
27 words
The method of claim 24, further comprising: evaluating the relative strengths of received pilot signals; and requesting a connection to a base station based upon the evaluation.
Claim 29
Dependent Claim
21 words
The method of claim 25, further comprising: requesting a release from a connection to a base station based upon the evaluation.
Claim 30
Dependent Claim
39 words
The method of claim 24, further comprising: determining whether to transmit the strengths of received pilot signals to one of the base stations based upon relative strengths of the pilot signals received from the base station and determined thresholds.
Claim 31
Dependent Claim
48 words
The method of claim 24, further comprising: determining a connect threshold based upon relative strengths of pilot signals received by the mobile unit; and initiating a connection to a particular base station based upon a comparison of the strength of a respective pilot signal to the connect threshold.
Claim 32
Dependent Claim
27 words
The method of claim 28, further comprising: determining the connect threshold based upon relative strengths of pilot signals received by the mobile unit from connected base stations.
Claim 33
Dependent Claim
51 words
The method of claim 24, further comprising: determining a drop threshold based upon relative strengths of pilot signals received by the mobile unit; and initiating a drop of a connection with a particular base station based upon a comparison of the strength of a respective pilot signal to the drop threshold.
Claim 34
Dependent Claim
56 words
The method of claim 24, further comprising: notifying the base station of strengths of the received pilot signals; and determining by the base station whether to establish a connection between the mobile unit and one of the base stations based upon the difference in strength between the strongest pilot signal and a corresponding weaker pilot signal.
Claim 35
Dependent Claim
35 words
The method of claim 31, further comprising: determining by the base station whether to drop a connection between the mobile unit and one of the base stations based upon relative strengths of the pilot signals.
Claim 36
Independent Claim
126 words
A method of operating a wireless communication system that facilitates wireless communication with a mobile unit operating within a respective service area, the method comprising: broadcasting a plurality of pilot signals, each of pilot signals corresponding to a respective one of a plurality sectors provided by a base station; receiving, by the mobile unit, a plurality of received pilot signals; measuring respective strengths of the received pilot signals, the received pilot signals including a strongest pilot signal and a plurality of weaker pilot signals; and determining whether to establish a connection between the mobile unit and a sector of the base station that corresponds to a weaker pilot signal based upon the difference in strength between the strongest pilot signal and the corresponding weaker pilot signal.
Claim 37
Independent Claim
126 words
A method of operating a wireless communication system that facilitates wireless communication with a mobile unit operating within a respective service area, the method comprising: broadcasting a plurality of pilot signals, each of pilot signals corresponding to a respective one of a plurality sectors provided by a base station; receiving, by the mobile unit, a plurality of received pilot signals; measuring respective strengths of the received pilot signals, the received pilot signals including a strongest pilot signal and a plurality of weaker pilot signals; and determining whether to establish a connection between the mobile unit and a sector of the base station that corresponds to a weaker pilot signal based upon the difference in strength between the strongest pilot signal and the corresponding weaker pilot signal.
Claim 38
Dependent Claim
26 words
The method of claim 33, further comprising: evaluating the relative strengths of received pilot signals; and requesting a connection to a sector based upon the evaluation.
Claim 39
Dependent Claim
20 words
The method of claim 34, further comprising: requesting a release from a connection to a sector based upon the evaluation.
Claim 40
Dependent Claim
32 words
The method of claim 33, further comprising: determining whether to transmit the relative strengths of received pilot signals to the base station based upon strengths of the pilot signals and determined thresholds.
Claim 41
Dependent Claim
47 words
The method of claim 33, further comprising: determining a connect threshold based upon relative strengths of pilot signals received by the mobile unit; and initiating a connection to a particular sector based upon a comparison of the strength of a respective pilot signal to the connect threshold.
Claim 42
Dependent Claim
30 words
The method of claim 37, further comprising: determining the connect threshold based upon relative strengths of pilot signals received by the mobile unit corresponding to at least some connected sectors.
Claim 43
Dependent Claim
50 words
The method of claim 33, further comprising: determining a drop threshold based upon relative strengths of pilot signals received by the mobile unit; and initiating a drop of a connection with a particular sector based upon a comparison of the strength of a respective pilot signal to the drop threshold.
Claim 44
Dependent Claim
57 words
The method of claim 33, further comprising: notifying the base station of strengths of received pilot signals; and determining by the base station whether to establish a connection between the mobile unit and one of the sectors of the base station based the difference in strength between the strongest pilot signal and the corresponding weaker pilot signal.
Claim 45
Dependent Claim
38 words
The method of claim 40, further comprising: determining by the base station whether to drop a connection between the mobile unit and one of the sectors of the base station based upon relative strengths of the pilot signals.
References Cited (Backward Citations)
US5175867A
Cited
US5267261A
Cited
US5640414A
Cited
US5454026A
Cited
US5455963A
Cited
US5499386A
Cited
US5432843A
Cited
US5517674A
Cited
US5483669A
Cited
US5623484A
Cited
US5625876A
Cited
US5548808A
Cited
US5732347A
Cited
US5673307A
Cited
US5491837A
Cited
US5794149A
Cited
US5722073A
Cited
US5848063A
Cited
US5854785A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-03-14 | 2003-09-13 | 2004-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-03-14 | 2007-09-13 | 2008-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-03-14 | 2011-09-13 | 2012-03-14 | $7700.00 | Window Closed / Lapsed |