Patent EP0565507A2 successfully refreshed from Google Patents.
EP0565507A2
Expired / Lapsed
EP
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Power control for random access call set-up in a mobile telephone system
Assignee: Ericsson Inc
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Filing: 1993-04-01
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Granted: —
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Expires: 2013-04-01
Abstract
Abstract The present invention includes a system and method for minimizing interference between two radio stations, e.g., a mobile radio telephone and a fixed base station, at the initiation of a radio communication. A mobile station initiates a random access at the lowest power level and increases the transmission power level until the base station detects the access signal. Once detected, the power level of the message is maintained at the detected level so that the signal interference is avoided. The present invention also provides a mechanism for synchronizing random access communications between mobile stations and the base station despite variation in distances between the mobile and base stations.
Inventors
- 👤 Paul W. Dent
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 13:50
CPC Classifications
H; H04; H04W; H04W56/00; H04W56/004; H04W56/0045; H04J; H04J13/00; H04J13/0007; H04J13/004; H04W52/00; H04W52/04; H04W52/38; H04W52/48; H04W52/50; H04B; H04B2201/00; H04B2201/69; H04B2201/707; H04B2201/7097; H04B2201/709709
Claims Analysis
Total Claims: 48
Claim 1
Independent Claim
94 words
A method for minimizing interference caused by radio communications initiated between at least one of a plurality of first radio stations and a second radio station, comprising the steps of: transmitting from said at least one first radio station an access message at a relatively low power level; determining whether said access message has been detected by said second radio station; retransmitting said access message at an increased power level until said access message is detected; and upon detecting said access message, transmitting power setting information for said first station from said second station.
Claim 2
Independent Claim
94 words
A method for minimizing interference caused by radio communications initiated between at least one of a plurality of first radio stations and a second radio station, comprising the steps of: transmitting from said at least one first radio station an access message at a relatively low power level; determining whether said access message has been detected by said second radio station; retransmitting said access message at an increased power level until said access message is detected; and upon detecting said access message, transmitting power setting information for said first station from said second station.
Claim 3
Dependent Claim
23 words
A method according to claim 1 wherein said first station is a mobile radio telephone and said second station is a base station.
Claim 4
Dependent Claim
22 words
A method according to claim 1 wherein said access message includes an access code and an identification code of said first station.
Claim 5
Dependent Claim
16 words
A method according to claim 1 wherein said access message is transmitted using spread-spectrum signal coding.
Claim 6
Dependent Claim
15 words
A method according to claim 4 wherein said access message includes orthogonal block error-correction codes.
Claim 7
Dependent Claim
27 words
A method according to claim 4 wherein said transmitting step includes: scrambling said access message using a scrambling code selected from a reserved group of scrambling codes.
Claim 8
Dependent Claim
20 words
A method according to claim 6 wherein said scrambling codes are identifiable from information broadcast on a common calling channel.
Claim 9
Dependent Claim
18 words
A method according to claim 1 further comprising: acknowledging at said second station reception of said access message.
Claim 10
Dependent Claim
20 words
A method according to claim 8 wherein said acknowledging step includes commanding said first station to discontinue power level increases.
Claim 11
Dependent Claim
20 words
A method according to claim 1 wherein a time of transmission said access message is based on said power level.
Claim 12
Dependent Claim
14 words
A method according to claim 8 wherein acknowledging step includes transmitting time alignment information.
Claim 13
Dependent Claim
14 words
A method according to claim 8 wherein acknowledging step includes transmitting power adjustment information.
Claim 14
Dependent Claim
35 words
A method according to claim 1 further comprising the step of terminating said radio communication including gradually diminishing said power level and terminating said communication when said power level has diminished by a predetermined extent.
Claim 15
Dependent Claim
16 words
A method according to claim 13 wherein said terminating step includes entering a discontinuous transmission mode.
Claim 16
Dependent Claim
81 words
A mobile radio station for communicating with at least one other radio station, comprising: means for transmitting from said mobile station to said other radio station a random access message at a relatively low power level; means for detecting an reply message from said other radio station; and means for commanding said transmitting means to retransmit said random access message at an increased power level if said reply message has not been detected to include an acknowledgement supplying power setting information.
Claim 17
Dependent Claim
81 words
A mobile radio station for communicating with at least one other radio station, comprising: means for transmitting from said mobile station to said other radio station a random access message at a relatively low power level; means for detecting an reply message from said other radio station; and means for commanding said transmitting means to retransmit said random access message at an increased power level if said reply message has not been detected to include an acknowledgement supplying power setting information.
Claim 18
Dependent Claim
20 words
The mobile station according to claim 15, wherein said retransmitting means increases said power level according to a ramp function.
Claim 19
Dependent Claim
36 words
The mobile station according to claim 15, wherein said transmitting means includes: means for selecting a scrambling code from a list of scrambling codes broadcast from said other radio station to generate said random access message.
Claim 20
Dependent Claim
26 words
The mobile station according to claim 15, further comprising: means for adjusting the time of transmission of said access message based on said increased power level.
Claim 21
Dependent Claim
92 words
A communications system, comprising: plural mobile radiotelephone stations, each mobile station including: means for transmitting an access message initially at a relatively low power level; means for regulating the power level of said transmitting means; and control means for controlling said regulating means depending on whether said access message has been detected; at least one base station including: means for receiving a composite of signals from said mobile stations; means for detecting said access messages; and means for transmitting a reply message to the mobile station corresponding to said detected access message.
Claim 22
Dependent Claim
92 words
A communications system, comprising: plural mobile radiotelephone stations, each mobile station including: means for transmitting an access message initially at a relatively low power level; means for regulating the power level of said transmitting means; and control means for controlling said regulating means depending on whether said access message has been detected; at least one base station including: means for receiving a composite of signals from said mobile stations; means for detecting said access messages; and means for transmitting a reply message to the mobile station corresponding to said detected access message.
Claim 23
Dependent Claim
44 words
The system according to claim 19, wherein said base station further comprises: means for ordering received signals including said access messages according to signal strength; means for selectively decoding the strongest signal; and means for removing said decoded signal from said received composite signal.
Claim 24
Dependent Claim
38 words
The system according to claim 20, wherein each mobile station includes: means for encoding access messages using orthogonal or bi-orthogonal codes to produce coded access messages; and means for scrambling said coded access messages using unique scrambling codes.
Claim 25
Dependent Claim
16 words
The system according to claim 21, wherein said scrambling codes are reserved for random access messages.
Claim 26
Dependent Claim
31 words
The system according to claim 22, wherein said base station transmitting means broadcasts a list of said reserved scrambling codes that enables the mobile station to determine an available access code.
Claim 27
Dependent Claim
29 words
The system according to claim 22, wherein said base station transmitting means broadcasts a list of said reserved scrambling codes separate from scrambling codes used for other radio communications.
Claim 28
Dependent Claim
25 words
The system according to claim 22, wherein said base station transmitting means broadcasts a list of said reserved scrambling codes used for other radio communications.
Claim 29
Dependent Claim
21 words
The system according to claim 19, wherein said access message includes a mobile station identification code and a random access code.
Claim 30
Dependent Claim
39 words
The system according to claim 19, wherein each mobile station includes means for adjusting the time of transmission of said access message based on said regulated power level; and means for detecting time alignment information in said reply message.
Claim 31
Dependent Claim
35 words
The system according to claim 27, wherein said base station includes means for determining the difference between the signal strength of said random access message detected at said base station and a predetermined signal strength.
Claim 32
Dependent Claim
26 words
The system according to claim 28, wherein said determining means determines a time difference between the time said random access was detected and a predetermined time.
Claim 33
Dependent Claim
22 words
The system according to claim 19, wherein said receiving means includes means for detecting preset signal patterns associated with said first message.
Claim 34
Dependent Claim
14 words
The system according to claim 30, wherein said detecting means is a RAKE detector.
Claim 35
Dependent Claim
21 words
The system according to claim 19, wherein said base station detecting means searches for particular access messages at staggered time intervals.
Claim 36
Independent Claim
117 words
A method for establishing radio communications between at least one of a plurality of first radio stations and at least one second radio station, comprising the steps of: selecting, by at least one of said first stations, a lightly loaded channel of said at least one second stations; and, following a random access procedure including selecting, by said first station, a scrambling code identified from a list of codes broadcast by said second station; transmitting, by said first station, a call initiation message including said selected code at a relatively low power level; and gradually increasing, by said first station, said power level of said transmitted message until an acknowledgement message is received from said second station.
Claim 37
Independent Claim
117 words
A method for establishing radio communications between at least one of a plurality of first radio stations and at least one second radio station, comprising the steps of: selecting, by at least one of said first stations, a lightly loaded channel of said at least one second stations; and, following a random access procedure including selecting, by said first station, a scrambling code identified from a list of codes broadcast by said second station; transmitting, by said first station, a call initiation message including said selected code at a relatively low power level; and gradually increasing, by said first station, said power level of said transmitted message until an acknowledgement message is received from said second station.
Claim 38
Dependent Claim
48 words
A method according to claim 33, wherein said channel selection step includes receiving and decoding signals on channels from one or more of said second radio stations at various radio frequencies; determining the load on each received channel; and selecting a lightly loaded channel with clear reception qualities.
Claim 39
Dependent Claim
36 words
A method according to claim 33, wherein said random access procedure further includes starting said random access procedure upon receipt of an call initiation signal transmitted by one of said first station and said second station.
Claim 40
Dependent Claim
90 words
A method according to claim 35, wherein said random access procedure further includes determining, by said second station, whether a code from said list of codes is being transmitted by a first station; transmitting, by said second station, an acknowledgement message upon receipt and decoding of said transmitted message using said selected code; transmitting, by said first station, a second message to said second station upon detection of said acknowledgement message; and ceasing transmission of said acknowledgement message by said second station upon receipt and decoding of said second message.
Claim 41
Dependent Claim
27 words
A method according to claim 33, wherein said acknowledgement message is transmitted on a common calling channel and includes an timing adjustment information by said second station.
Claim 42
Dependent Claim
32 words
A method according to claim 36, wherein said second station transmits said acknowledgement message initially at a low power level and gradually increases said power level until receipt of said second message.
Claim 43
Dependent Claim
14 words
A method according to claim 36, wherein said second message includes signal strength information.
Claim 44
Dependent Claim
23 words
A method according to claim 35, wherein said first station receives said acknowledgement message from both common calling channel and said selected channel.
Claim 45
Dependent Claim
38 words
A method according to claim 33 further comprising the step of terminating said communication including gradually diminishing said power level of said transmitted message and terminating said communication when said power level is diminished by a predetermined extent.
Claim 46
Independent Claim
54 words
A method for minimizing interference caused by termination of radio communications between a first radio station and a second radio station, comprising the steps of: entering a call termination mode after a last communication segment; gradually diminishing a transmission power level; and terminating transmission when said power level has diminished by a predetermined extent.
Claim 47
Independent Claim
54 words
A method for minimizing interference caused by termination of radio communications between a first radio station and a second radio station, comprising the steps of: entering a call termination mode after a last communication segment; gradually diminishing a transmission power level; and terminating transmission when said power level has diminished by a predetermined extent.
Claim 48
Dependent Claim
28 words
A method according to claim 39, wherein said termination mode is a discontinuous transmission mode in which frames of data are reduced to no more than two flags.
References Cited (Backward Citations)
No citation records indexed.
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