US5276908A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Call set-up and spectrum sharing in radio communication on systems with dynamic channel allocation
Assignee: Nortel Networks Ltd
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Filing: 1990-10-25
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Granted: 1994-01-04
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Expires: 2010-10-25
Abstract
Abstract The call set-up technique of this invention is characterized by the use of channel information from both base station and subscriber terminal in determining the radio traffic channel upon which to set-up a new call. Communication between the base station and subscriber terminal is carried out on a signalling channel until the traffic channel is chosen. Calls are set-up so that they proceed on the radio channel which, of a set of channels under consideration by the subscriber terminal, contains the least amount of interference as measured at the subscriber terminal. The set of channels under consideration by the subscriber terminal is a subset of the entire set of channels allocated to the service. This subset is made up of those channels having little interference, as measured by the base station, and which, additionally, are not reserved exclusively for stationary, fixed-allocation services in the geographic location of the base station. The call set-up technique thereby assures that calls proceed on channels containing little interference from the viewpoints of both base station and subscriber terminal. The technique also facilitates sharing of the radio spectrum with stationary, fixed-allocation services because there is no need to program each subscriber terminal to avoid the spectrum allocated to the fixed service.
Inventors
- 👤 Mahshad Koohgoli
- 👤 Sorin Cohn-Sfetcu
- 👤 John D. Lockton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 17:19
CPC Classifications
H; H04; H04M; H04M1/00; H04M1/72; H04M1/725; H04M1/72502; H04M1/72505; H04M1/72511; H04W; H04W72/00; H04W72/50; H04W72/54; H04W72/541; H04W16/00; H04W16/14; H04W72/56; H04W72/563
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
165 words
In a radio communication system operating within a specific radio spectrum and having a number of base stations, each communicating with a plurality of subscriber terminals over separate radio channels, a method of determining the availability of radio channels for use between said base station and said subscriber terminals, said base stations being located in geographical regions wherein varying portions of the radio spectrum in each of said geographical regions are reserved for fixed radio transmission services, the method comprising the steps of: identifying the range of frequencies which is reserved for said fixed radio transmission services in a said base station's geographical region; selecting, from a plurality of radio channels covering the radio spectrum, those radio channels that lie outside of the reserved range of frequencies for said base station's geographical region; and registering, at the said base station associated with the geographical region, signalling and radio traffic channels that can be allocated from those channels that lie outside the reserved range of frequencies.
Claim 2
Dependent Claim
165 words
In a radio communication system operating within a specific radio spectrum and having a number of base stations, each communicating with a plurality of subscriber terminals over separate radio channels, a method of determining the availability of radio channels for use between said base station and said subscriber terminals, said base stations being located in geographical regions wherein varying portions of the radio spectrum in each of said geographical regions are reserved for fixed radio transmission services, the method comprising the steps of: identifying the range of frequencies which is reserved for said fixed radio transmission services in a said base station's geographical region; selecting, from a plurality of radio channels covering the radio spectrum, those radio channels that lie outside of the reserved range of frequencies for said base station's geographical region; and registering, at the said base station associated with the geographical region, signalling and radio traffic channels that can be allocated from those channels that lie outside the reserved range of frequencies.
Claim 3
Dependent Claim
46 words
A method as defined in claim 1, wherein said radio channels are registered by: storing at the base station, a list of available radio channels comprised of traffic and signalling channels which can be allocated in the geographical region where the said base station is located.
Claim 4
Dependent Claim
408 words
In a radio communication system operating within a specified radio spectrum and having a number of base stations, each communicating with a plurality of subscriber terminals over separate radio channels and each base station having access to each of said plurality of radio channels, a method of selecting a radio traffic channel for completing call set-up of incoming and outgoing calls between a base station, a subscriber terminal and the Public Switched Telephone Network (PSTN), said base stations being located in geographical regions wherein varying portions of the radio spectrum in each of said geographical regions are reserved for fixed radio transmission services, the method comprising the steps of: identifying the range of frequencies which is reserved for said fixed radio transmission services in a said base station's geographical region; selecting for allocation, from a plurality of radio channels covering the radio spectrum, those radio channels that lie outside of the reserved range of frequencies for said base station`s geographical region; registering, at each of said base stations, signalling and radio traffic channels that can be allocated; receiving at a said base station, an incoming call attempt from a subscriber or from the PSTN; scanning, at the said base station, said radio traffic channels that can be allocated at the said base station for the presence of radio power levels above a first specified threshold; measuring the power level of a scanned traffic channel; selecting from the scanned traffic channels, traffic channels with radio power levels below said first specified threshold; storing a list of selected traffic channels; sending, to the subscriber terminals, the list stored at said base station; receiving the list of selected channels at the subscriber terminal; scanning at the subscriber terminal the traffic channels on said list for the presence of radio power levels above a second specified threshold; measuring at the subscriber terminal the power level on a scanned traffic channel on said list; selecting at the subscriber terminal from the scanned traffic channels of the list, traffic channels with radio power levels below said second specified threshold; storing the selected traffic channels at said subscriber terminal; sending, to the said base station, along the signalling channel, a traffic channel selection comprised of a first preferred traffic channel and a second redundant traffic channel; receiving the traffic channel selection at the said base station; switching the said base station and the subscriber terminal to the preferred traffic channel; and proceeding with call connection.
Claim 5
Dependent Claim
408 words
In a radio communication system operating within a specified radio spectrum and having a number of base stations, each communicating with a plurality of subscriber terminals over separate radio channels and each base station having access to each of said plurality of radio channels, a method of selecting a radio traffic channel for completing call set-up of incoming and outgoing calls between a base station, a subscriber terminal and the Public Switched Telephone Network (PSTN), said base stations being located in geographical regions wherein varying portions of the radio spectrum in each of said geographical regions are reserved for fixed radio transmission services, the method comprising the steps of: identifying the range of frequencies which is reserved for said fixed radio transmission services in a said base station's geographical region; selecting for allocation, from a plurality of radio channels covering the radio spectrum, those radio channels that lie outside of the reserved range of frequencies for said base station`s geographical region; registering, at each of said base stations, signalling and radio traffic channels that can be allocated; receiving at a said base station, an incoming call attempt from a subscriber or from the PSTN; scanning, at the said base station, said radio traffic channels that can be allocated at the said base station for the presence of radio power levels above a first specified threshold; measuring the power level of a scanned traffic channel; selecting from the scanned traffic channels, traffic channels with radio power levels below said first specified threshold; storing a list of selected traffic channels; sending, to the subscriber terminals, the list stored at said base station; receiving the list of selected channels at the subscriber terminal; scanning at the subscriber terminal the traffic channels on said list for the presence of radio power levels above a second specified threshold; measuring at the subscriber terminal the power level on a scanned traffic channel on said list; selecting at the subscriber terminal from the scanned traffic channels of the list, traffic channels with radio power levels below said second specified threshold; storing the selected traffic channels at said subscriber terminal; sending, to the said base station, along the signalling channel, a traffic channel selection comprised of a first preferred traffic channel and a second redundant traffic channel; receiving the traffic channel selection at the said base station; switching the said base station and the subscriber terminal to the preferred traffic channel; and proceeding with call connection.
Claim 6
Dependent Claim
30 words
A method as defined in claim 3, wherein said plurality of traffic channels are scanned by switching the said base station on an available frequency channel using frequency synthesizer means.
Claim 7
Dependent Claim
22 words
A method as defined in claim 4, wherein said traffic channels are scanned regularly to maintain a list of useable traffic channels.
Claim 8
Dependent Claim
30 words
A method as defined in claim 3, wherein said radio traffic channels that can be allocated are registered by: storing at the said base station the allocatable radio traffic channels.
Claim 9
Dependent Claim
33 words
A method as defined in claim 3, further comprising the step of selecting radio signalling channels whose frequencies lie outside of the reserved range of frequencies for the said base station's geographical region.
Claim 10
Dependent Claim
25 words
A method as defined in claim 7, further comprising the step of storing at the said base station a list of the selected signalling channels.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-01-03 | 1997-07-05 | 1998-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-01-03 | 2001-07-05 | 2002-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-01-03 | 2005-07-05 | 2006-01-04 | $7700.00 | Window Closed / Lapsed |