US5930714A
Expired / Lapsed
US
⏱️ 0.0 years remaining
CDMA inter-mobile switching center soft hand-off
Assignee: Nortel Networks Ltd
•
Filing: 1996-10-24
•
Granted: 1999-07-27
•
Expires: 2016-10-24
Abstract
Abstract The present invention facilitates an inter-mobile switching center (MSC) soft hand-off by creating a communication link between the MSCs through the base station controllers (BSCs). The routers in the BSCs are linked to form a virtual router. This faster link between the BSCs enables the same protocol to be used for intra-MSC soft hand-off used for inter-MSC soft hand-off.
Inventors
- 👤 Marwan Abu-Amara
- 👤 Steve Sides
- 👤 Ahmad Jalali
- 👤 Jyoti Boppana
- 👤 Satyajit Doctor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 18:49
CPC Classifications
H; H04; H04W; H04W36/00; H04W36/12; H04W36/0005; H04W36/0055; H04W36/0069; H04W36/00692
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
138 words
A method for a soft hand-off of a radiotelephone call from a source cellular system to a target cellular system, the source cellular system comprising a source mobile switching center and a source vocoder and the target cellular system comprising a target mobile switching center and a target vocoder, both the source and target mobile switching centers coupled to a public switched telephone network, the source and target vocoders each comprising a selector, the method comprising the steps of: coupling the source vocoder and the target vocoder; the radiotelephone transmitting, to the source vocoder, a signal that indicates a desire to add the target cell; the source vocoder controlling the radiotelephone call; the target cellular system allocating a selector; the target cellular system allocating a radio; and the source vocoder instructing the radiotelephone to add the target cell.
Claim 2
Independent Claim
138 words
A method for a soft hand-off of a radiotelephone call from a source cellular system to a target cellular system, the source cellular system comprising a source mobile switching center and a source vocoder and the target cellular system comprising a target mobile switching center and a target vocoder, both the source and target mobile switching centers coupled to a public switched telephone network, the source and target vocoders each comprising a selector, the method comprising the steps of: coupling the source vocoder and the target vocoder; the radiotelephone transmitting, to the source vocoder, a signal that indicates a desire to add the target cell; the source vocoder controlling the radiotelephone call; the target cellular system allocating a selector; the target cellular system allocating a radio; and the source vocoder instructing the radiotelephone to add the target cell.
Claim 3
Dependent Claim
23 words
The method of claim 1 and further including the step of the radiotelephone indicating, to the source vocoder, the completion of the hand-off.
Claim 4
Dependent Claim
30 words
The method of claim 1 and further including the step of the target cellular system indicating to the source cell system the successful allocation of the selector and the radio.
Claim 5
Independent Claim
104 words
A method for handing off a radiotelephone call from a source cellular system to a target cellular system, the source cellular system comprising a source mobile switching center, a source vocoder, and a source base transceiver, the target cellular system comprising a target mobile switching center, a target vocoder, and a target base transceiver, the target and source mobile switching centers each having public switched telephone network trunks, the method comprising the steps of: performing a hand-off from the source base transceiver to the target base transceiver; and switching from the source vocoder as controlling vocoder to the target vocoder as the controlling vocoder.
Claim 6
Independent Claim
104 words
A method for handing off a radiotelephone call from a source cellular system to a target cellular system, the source cellular system comprising a source mobile switching center, a source vocoder, and a source base transceiver, the target cellular system comprising a target mobile switching center, a target vocoder, and a target base transceiver, the target and source mobile switching centers each having public switched telephone network trunks, the method comprising the steps of: performing a hand-off from the source base transceiver to the target base transceiver; and switching from the source vocoder as controlling vocoder to the target vocoder as the controlling vocoder.
Claim 7
Dependent Claim
60 words
The method of claim 4 wherein the step of performing the hand-off further includes the steps of: the radiotelephone transmitting a message to the source vocoder indicating a desire to add the target base transceiver; the source vocoder transmitting a first hand-off direction message to the radiotelephone; and the radiotelephone transmitting a first hand-off completion message to the source vocoder.
Claim 8
Dependent Claim
65 words
The method of claim 4 wherein the step of switching further includes the steps of: the source vocoder transmitting a vocoder switch request to the target vocoder; the target vocoder transmitting a vocoder switch message to the target base transceiver; and the target base transceiver acknowledging, to the target vocoder, the vocoder switch message; and the target vocoder acknowledging the switch to the source vocoder.
Claim 9
Dependent Claim
119 words
The method of claim 4 and further including the steps of: target vocoder transmitting a second hand-off direction message to the radiotelephone; the radiotelephone transmitting a second hand-off completion message to the target vocoder; the target vocoder indicating to the target mobile switching center that the target vocoder is the controlling vocoder; the target mobile switching center directing the source mobile switching center to switch its public switched telephone network trunk to an allocated voice trunk; the source mobile switching center switching its public switched telephone network trunk to the allocated voice trunk; and the source mobile switching center indicating to the source vocoder that the public switched telephone network trunk has been switched to the allocated voice trunk.
Claim 10
Independent Claim
126 words
A method for handing off a radiotelephone call from a source cellular system to a target cellular system, the source cellular system comprising a source mobile switching center, a source vocoder, a source router, and a source base transceiver, the target cellular system comprising a target mobile switching center, a target vocoder, a target router, and a target base transceiver, the target and source mobile switching centers each having public switched telephone network trunks, the method comprising the steps of: providing a link between the source router and the target router; performing a soft hand-off of the radiotelephone between the source cellular system and the target cellular system; and performing a hard hand-off of the radiotelephone between the source cellular system and the target cellular system.
Claim 11
Independent Claim
126 words
A method for handing off a radiotelephone call from a source cellular system to a target cellular system, the source cellular system comprising a source mobile switching center, a source vocoder, a source router, and a source base transceiver, the target cellular system comprising a target mobile switching center, a target vocoder, a target router, and a target base transceiver, the target and source mobile switching centers each having public switched telephone network trunks, the method comprising the steps of: providing a link between the source router and the target router; performing a soft hand-off of the radiotelephone between the source cellular system and the target cellular system; and performing a hard hand-off of the radiotelephone between the source cellular system and the target cellular system.
Claim 12
Dependent Claim
48 words
The method of claim 8 wherein the step of performing the hard hand-off further includes the steps of: allocating the target vocoder; allocating a radio resource in the target base transceiver; the target MSC allocating a voice trunk; and directing the radiotelephone to tune to the radio resource.
Claim 13
Dependent Claim
42 words
The method of claim 9 and further including the steps of: the target vocoder indicating that it is in control of the radiotelephone call; and the source mobile switching center switching its public switched telephone network trunk to the allocated voice trunk.
References Cited (Backward Citations)
US5168498A
Cited
US5101501A
Cited
US5146609A
Cited
WO1994001975A1
Cited
US5487065A
Cited
US5471644A
Cited
WO1995015665A1
Cited
US5572528A
Cited
WO1996036191A1
Cited
US5682416A
Cited
US5530693A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-07-26 | 2003-01-25 | 2003-07-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-07-26 | 2007-01-25 | 2007-07-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-07-26 | 2011-01-25 | 2011-07-27 | $7700.00 | Window Closed / Lapsed |