Patent US5428601A successfully refreshed from Google Patents.
US5428601A
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US
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Method of operating a communications system, a communications system and a secondary station for use in the system
Assignee: US Philips Corp
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Filing: 1994-03-29
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Granted: 1995-06-27
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Expires: 2014-03-29
Abstract
Abstract A method of operating a communications system, particularly a FDM-TDD cordless telephony system, in which, in order to expedite handover, a portable secondary station builds up a record of the status and quality of the other FDM channels in the system by every 1 in n (where n is an integer greater than one) TDD frames monitoring another FDM channel. The value of n is adaptive in that, as the quality of its existing channel deteriorates, the value of n decreases, thereby updating its record more rapidly. At handover, the secondary station is able to choose immediately an acceptable alternative channel, thereby avoiding the time overhead of scanning all the other FDM channels.
Inventors
- 👤 Frank C. G. Owen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:14
CPC Classifications
H; H04; H04M; H04M1/00; H04M1/72; H04M1/725; H04M1/733; H04W; H04W24/00; H04W36/00; H04W36/08; H04W36/24; H04W36/30; H04W36/06; H04W74/00
Claims Analysis
Total Claims: 38
Claim 1
Independent Claim
119 words
A method of operating a frequency division multiplex, FDM, -time division duplex, TDD, communications system comprising at least one primary station and one secondary station, Wherein the one primary and the one secondary station are communicating with each other in successive TDD frames in a plurality of FDM channels, each TDD frame including a transmit half frame and a receive half frame, the method comprising communicating between one secondary station and one primary station on one of the plurality FDM channels and monitoring, in the one secondary station, a channel quality parameter in at least one other FDM channel during the receive half frame of one of every n TDD frames, where n is an integer greater than one.
Claim 2
Independent Claim
119 words
A method of operating a frequency division multiplex, FDM, -time division duplex, TDD, communications system comprising at least one primary station and one secondary station, Wherein the one primary and the one secondary station are communicating with each other in successive TDD frames in a plurality of FDM channels, each TDD frame including a transmit half frame and a receive half frame, the method comprising communicating between one secondary station and one primary station on one of the plurality FDM channels and monitoring, in the one secondary station, a channel quality parameter in at least one other FDM channel during the receive half frame of one of every n TDD frames, where n is an integer greater than one.
Claim 3
Dependent Claim
39 words
A method as claimed in claim 1, further comprising the steps of monitoring the communicating one of the FDM channels; decreasing the value of n in response to the quality of the communicating one of the FDM channels deteriorating.
Claim 4
Dependent Claim
19 words
A method as claimed in claim 1, wherein the channel quality parameter monitored comprises a measurement of signal strength.
Claim 5
Dependent Claim
49 words
A method as claimed in claim 3, further comprising the steps of, in the secondary stations monitoring the communicating one of the FDM channels; and altering the value of n in response to a 10 dB change in the signal strength of the communicating one of the FDM channels.
Claim 6
Dependent Claim
79 words
A method as claimed in claim 1, wherein the monitoring step comprises monitoring the channel quality parameter in a plurality of other FDM channels; and further comprising the step of storing, in the secondary station in response to the monitoring step, a respective indication of the quality of each of the plurality of other FDM channels, whereby the primary station need not communicate a list of free channels to the secondary station and need not determine such a list.
Claim 7
Dependent Claim
107 words
A method as claimed in claim 5, further comprising the steps of in the secondary station, monitoring the quality of the communicating one of the FDM channels; and transmitting, by the one secondary station, in response to an indication that the quality of the communicating one of the FDM channels has deteriorated below an acceptable level, a request for handover of a call to one of the other FDM channels that according to the stored indications is of acceptable quality, said transmitting being made on the one of the other FDM channels during the transmit half frame of a sequence of one in every n TDD frames.
Claim 8
Dependent Claim
34 words
A method as claimed in claimed in claim 6, further comprising the step of initiating the handover in response to a bit error rate in the communicating one of the FDM channels becoming unacceptable.
Claim 9
Dependent Claim
31 words
A method as claimed in claim 6, further comprising the step of initiating the handover in response to a signal strength in the communicating one of the FDM channels becoming unacceptable.
Claim 10
Dependent Claim
30 words
A method as claimed in claim 6, further comprising the step of initiating the handover in response to clock jitter being detected in the communicating one of the FDM channels.
Claim 11
Dependent Claim
61 words
A method as claimed in claim 1, wherein the communicating step comprises receiving, in the one secondary station, a received signal from the one primary station; and further comprising the step of, in the one secondary station, repeating a preceding TDD frame of the received signals during the one of every n TDD frames, whereby data lost during monitoring is replaced.
Claim 12
Dependent Claim
59 words
A method as claimed in claim 1, wherein each FDM channel includes a control channel, and further comprising the steps of transmitting, by the one primary station, data bits relating to the one secondary station's identity over a plurality of TDD frames, and inserting, by the one secondary station, data bits to replace those lost during the monitoring step.
Claim 13
Dependent Claim
36 words
A method as claimed in claim 11, wherein the data bits inserted correspond to those bits relating to the one secondary station's identity which should have been present in the one in every n TDD frames.
Claim 14
Dependent Claim
58 words
A method as claimed in claim 11, wherein the data bits are binary bits and in an error checking process in the one secondary station, various combinations of binary bits are inserted at those locations in the one secondary s station's identity which would have been filled by the bits in the one in every n TDD frames.
Claim 15
Dependent Claim
27 words
The method of claim 1 wherein there are a plurality of pairs of primary and secondary stations all performing the communicating and monitoring steps of the method.
Claim 16
Dependent Claim
14 words
Method of claim 1 in which the primary station does not monitor channel quality.
Claim 17
Dependent Claim
115 words
A frequency division multiplex, FDM, -time division duplex, TDD, communications system comprising at least one primary station and at least one secondary station for communicating with the primary station over one of a plurality of FDM channels, the secondary station including a transmitter, a receiver, means for tuning the transmitter and receiver to any one of the FDM channels, control means for causing the tuning means to retune at least the receiver, for a receive half frame of one in every n TDD frames, to at least one other FDM channel, where n is an integer greater than one, and means for monitoring a channel quality parameter in the at least one other FDM channel.
Claim 18
Dependent Claim
115 words
A frequency division multiplex, FDM, -time division duplex, TDD, communications system comprising at least one primary station and at least one secondary station for communicating with the primary station over one of a plurality of FDM channels, the secondary station including a transmitter, a receiver, means for tuning the transmitter and receiver to any one of the FDM channels, control means for causing the tuning means to retune at least the receiver, for a receive half frame of one in every n TDD frames, to at least one other FDM channel, where n is an integer greater than one, and means for monitoring a channel quality parameter in the at least one other FDM channel.
Claim 19
Dependent Claim
61 words
A system as claimed in claim 16, wherein the secondary station has storage means for storing indications of the quality of the at least one other FDM channel, in response to an output of the means for monitoring, whereby the primary station need not communicate a list of free channels to the secondary station and need not determine such a list.
Claim 20
Dependent Claim
51 words
A system as claimed in claim 17, wherein the secondary station has means for monitoring the quality of the communicating one of the FDM channels and the control means is adapted to reduce the value of n in response to the quality of the communicating one of the FDM channels deteriorating.
Claim 21
Dependent Claim
42 words
A system as claimed in claim 18, wherein the control means, in response to the communicating one of the FDM channels becoming unacceptable, initiates a handover routine to a channel which is acceptable according to the indications stored in the storage means.
Claim 22
Dependent Claim
63 words
A system as claimed in claim 19, wherein the control means instructs the tuning means to tune the transmitter to the frequency of the channel which the secondary station has selected as being acceptable in the transmit half frame of a sequence of the one in every n TDD frames in order to initiate negotiations connected with the handover of the secondary station.
Claim 23
Dependent Claim
32 words
The system of claim 18 wherein the means for monitoring the at least one other FDM channel and the means for monitoring the communicating FDM channel are the same means for monitoring.
Claim 24
Dependent Claim
50 words
A system as claimed in claim 16, wherein the secondary station has means for monitoring the quality of the communicating one of the FDM channels and the control means is adapted to reduce the value of n in response to the quality of the communicating one of FDM channels deteriorating.
Claim 25
Dependent Claim
31 words
The system of claim 22 wherein the means for monitoring the at least one other FDM channel and the means for monitoring the communicating FDM channel are same means for monitoring.
Claim 26
Dependent Claim
29 words
A system as claimed in claim 16, wherein the control means repeats signal data from a preceding TDD frame for that lost during operation of the means for monitoring.
Claim 27
Dependent Claim
45 words
A system as claimed in claim 16, wherein the secondary station has means for recovering its identity from data bits transmitted over a plurality of TDD frames; and the control means provides data bits to replace those lost during operation of the means for monitoring.
Claim 28
Dependent Claim
123 words
A secondary station for use in a frequency division multiplex, FDM, -time division duplex, TDD, communication system comprising at least one primary station and at least one secondary station for communicating with the primary station over a communicating one of a plurality of FDM channels, the secondary station comprising a transmitter, a receiver, means for tuning the transmitter and receiver to any one of the FDM channels, control means for causing the tuning means to retune at least the receiver, for a receive half frame of one in every n TDD frames, to at least one other FDM channel, where n is an integer greater than one, and means for monitoring a channel quality parameter in the at least one other FDM channel.
Claim 29
Dependent Claim
123 words
A secondary station for use in a frequency division multiplex, FDM, -time division duplex, TDD, communication system comprising at least one primary station and at least one secondary station for communicating with the primary station over a communicating one of a plurality of FDM channels, the secondary station comprising a transmitter, a receiver, means for tuning the transmitter and receiver to any one of the FDM channels, control means for causing the tuning means to retune at least the receiver, for a receive half frame of one in every n TDD frames, to at least one other FDM channel, where n is an integer greater than one, and means for monitoring a channel quality parameter in the at least one other FDM channel.
Claim 30
Dependent Claim
59 words
A secondary station as claimed in claim 26, further comprising storage means for storing indications of the quality of the at least one other FDM channel, in response to an output of the means for monitoring, whereby the primary station need not communicate a list of free channels to the secondary station and need not determine such a list.
Claim 31
Dependent Claim
50 words
The secondary station as claimed in claim 27, further comprising means for monitoring the quality of the communicating one of the FDM channels and wherein the control means is adapted to reduce the value of n in response to the quality of the communicating one of the FDM channels deteriorating.
Claim 32
Dependent Claim
43 words
A secondary station as claimed in claim 28, wherein the control means, in response to the communicating one of the FDM channels becoming unacceptable, initiates a handover routine to a channel which is acceptable according to the indications stored in the storage means.
Claim 33
Dependent Claim
61 words
A secondary station as claimed in claim 27, wherein the control means instructs the tuning means to tune the transmitter to the frequency of the channel which the secondary station has selected as being acceptable in a transmit half frame of a sequence of the one in every n TDD frames in order to initiate negotiations connected with the handover routine.
Claim 34
Dependent Claim
32 words
The system of claim 28 wherein the means for monitoring the at least one other FDM channel and the means for monitoring the communicating FDM channel are the same means for monitoring.
Claim 35
Dependent Claim
49 words
The secondary station as claimed in claim 26, further comprising means for monitoring the quality of the communicating one of the FDM channels and wherein the control means is adapted to reduce the value of n in response to the quality of the communicating one of FDM channels deteriorating.
Claim 36
Dependent Claim
32 words
The system of claim 32 wherein the means for monitoring the at least one other FDM channel and the means for monitoring the communicating FDM channel are the same means for monitoring.
Claim 37
Dependent Claim
30 words
A secondary station as claimed in claim 26, wherein the control means repeats signal data from a preceding TDD frame for that lost during operation of the means for monitoring.
Claim 38
Dependent Claim
44 words
A secondary station as claimed in claim 26, further comprising means for recovering its identity from data bits transmitted over a plurality of TDD frames; and wherein the control means provides data bits to replace those lost during operation of the means for monitoring.
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) | 1998-06-26 | 1998-12-26 | 1999-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-06-26 | 2002-12-26 | 2003-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-06-26 | 2006-12-26 | 2007-06-27 | $7700.00 | Window Closed / Lapsed |