Patent US1977819A successfully refreshed from Google Patents.
US5212684A
Expired / Lapsed
US
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Protocol and transceiver for cordless/cellular telephone service
Assignee: IPG Electronics 503 Ltd
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Filing: 1990-08-30
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Granted: 1993-05-18
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Expires: 2010-08-30
Abstract
Abstract A communications system suitable for use with hand portable radio telephones operating in a cellular mode, the typical cell size being between 500 m and 3 km radius. Each cell comprising at least one primary or base station (10) connected to the PSTN and one or more secondary portable stations (14) which are capable of roaming within the cell. Radio communication between the stations can be initiated by either station. Each primary and secondary station having radio transceiving means for time division duplex communication between the stations, a codec operating at 32 kbits/second or 11.4 kbits/second and means for transmitting digitised speech in accordance with a framed structure comprising 3 full rate or 6 half rate channels per carriers, the carrier being modulated at a carrier bit rate of substantially 270.8333 kbits/second. Provision is made for internal and external handover, if required. Also, if required, the secondary station can be constructed to operate in the DECT system as well as in the above described system.
Inventors
- 👤 Robert J. G. MacNamee
- 👤 Sunil K. Vadgama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:54
CPC Classifications
H; H04; H04W; H04W88/00; H04W88/02; H04M; H04M2250/00; H04M2250/08; H04W36/00; H04W36/14; H04W36/142
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
195 words
A communications system comprising a dual mode hand portable transceiver for metropolitan cellular and cordless telecommunications use, forming a secondary station, and a primary station, the primary and secondary stations each comprising respective radio transceiving means for duplex radio communication between the stations, said primary and secondary stations each further comprising: a single encoding means for digitizing speech to form transmitter digitized speech signals, and a single decoding means for recovering speech from received digitized speech signals, and means for formatting said digitized speech signals to produce a modulation signal according to a selected one of first and second protocols, selection of the protocol being responsive to control by a user of the transceiver, said first protocol using 3 full rate channels per carrier, with each channel carrying signals at substantially 32 kbits per second; and said second protocol using 2 half rate duplex channels carrying signals at substantially 11.4 kbits per second, and each respective transceiver comprising a single transmitter means for modulating a carrier with said modulation signal at a carrier bit rate of substantially 270.8333 kbits per second, and transmitting the resultant formatted transmitter digitized speech signals over a duplex channel system.
Claim 2
Dependent Claim
195 words
A communications system comprising a dual mode hand portable transceiver for metropolitan cellular and cordless telecommunications use, forming a secondary station, and a primary station, the primary and secondary stations each comprising respective radio transceiving means for duplex radio communication between the stations, said primary and secondary stations each further comprising: a single encoding means for digitizing speech to form transmitter digitized speech signals, and a single decoding means for recovering speech from received digitized speech signals, and means for formatting said digitized speech signals to produce a modulation signal according to a selected one of first and second protocols, selection of the protocol being responsive to control by a user of the transceiver, said first protocol using 3 full rate channels per carrier, with each channel carrying signals at substantially 32 kbits per second; and said second protocol using 2 half rate duplex channels carrying signals at substantially 11.4 kbits per second, and each respective transceiver comprising a single transmitter means for modulating a carrier with said modulation signal at a carrier bit rate of substantially 270.8333 kbits per second, and transmitting the resultant formatted transmitter digitized speech signals over a duplex channel system.
Claim 3
Dependent Claim
17 words
A system as claimed in claim 1, characterised in that the frame length is substantially 10 milliseconds.
Claim 4
Dependent Claim
24 words
A system as claimed in claim 1 characterised in that communication between the primary and secondary stations is by single frequency time division duplex.
Claim 5
Dependent Claim
38 words
A system as claimed in claim 3, characterised in that each channel comprises two slots and the message structure for each slot comprises successively a preamble, a training sequence, a signalling field, a data field and tail bits.
Claim 6
Dependent Claim
23 words
A system as claimed in claim 3 characterised in that broadcast, common and dedicated control channels are provided on the same radio carrier.
Claim 7
Dependent Claim
21 words
A system as claimed in claim 3 characterised in that broadcast and common control are provided on a reserved radio carrier.
Claim 8
Dependent Claim
19 words
A system as claimed in claim 1 characterised in that the modulation parameter (bandwidth x time) BT is 0.3.
Claim 9
Dependent Claim
25 words
A system as claimed in claim 7, having at least two carriers and characterised in that adjacent carriers are spaced apart by substantially 200 KHz.
Claim 10
Dependent Claim
22 words
A system as claimed in claim 1, characterised in that the primary station is connected to a public switched telephone network (PSTN).
Claim 11
Dependent Claim
34 words
A system as claimed in claim 1, characterised in that the primary and secondary stations each operate in accordance with a protocol which permits either station to initiate a call to the other station.
Claim 12
Dependent Claim
17 words
A system as claimed in claim 10, characterised in that each secondary station includes a channel equaliser.
Claim 13
Dependent Claim
26 words
A system as claimed in claim 1, characterised in that each primary station includes a channel equaliser for equalising a digital signal from the secondary station.
Claim 14
Dependent Claim
94 words
A system as claimed in claim 12, characterised in that each channel comprises two slots and the message structure for each slot comprises successively a preamble, a training sequence, a signalling field, a data field and tail bits; and the channel equaliser pre-distorts a digital signal to be transmitted to a secondary station, the degree of pre-distortion being determined on the basis that the channel is a reciprocal channel and that the adjustment of the equaliser coefficients using the training sequence is such that the signal received at the secondary station is substantially undistorted.
Claim 15
Dependent Claim
19 words
A system as claimed in claim 1 characterised in that the primary station has means to practise antenna diversity.
Claim 16
Dependent Claim
16 words
A system as claimed in claim 1 further comprising means for permitting internal and external handover.
Claim 17
Dependent Claim
20 words
A system as claimed in claim 1 characterised in that GSM signalling protocols are adapted to work on DECT channels.
Claim 18
Dependent Claim
48 words
A system as claimed in claim 1 having a signalling protocol comprising a physical layer, a link layer and network layer protocols, characterised in that at least some of the signalling messages for the link layer comprise short form messages which are contained in a single message frame.
Claim 19
Dependent Claim
152 words
A dual mode hand portable transceiver for metropolitan cellular and cordless telecommunications use, comprising: a single encoding means for digitizing speech to form transmitter digitized speech signals, and decoding means for recovering speech from received digitized speech signals, a single means for formatting said digitized speech signals to produce a modulation signal according to a selected one of first and second protocols, selection of the protocol being responsive to control by a user of the transceiver, said first protocol using 3 full rate channels per carrier, with each channel carrying signals at substantially 32 kbits per second; and said second protocol using 2 half rate duplex channels carrying signals at substantially 11.4 kbits per second, and a single means for modulating a carrier with said modulation signal at a carrier bit rate of substantially 270.8333 kbits per second, and transmitting the resultant formatted transmitter digitized speech signals over a duplex channel system.
Claim 20
Dependent Claim
152 words
A dual mode hand portable transceiver for metropolitan cellular and cordless telecommunications use, comprising: a single encoding means for digitizing speech to form transmitter digitized speech signals, and decoding means for recovering speech from received digitized speech signals, a single means for formatting said digitized speech signals to produce a modulation signal according to a selected one of first and second protocols, selection of the protocol being responsive to control by a user of the transceiver, said first protocol using 3 full rate channels per carrier, with each channel carrying signals at substantially 32 kbits per second; and said second protocol using 2 half rate duplex channels carrying signals at substantially 11.4 kbits per second, and a single means for modulating a carrier with said modulation signal at a carrier bit rate of substantially 270.8333 kbits per second, and transmitting the resultant formatted transmitter digitized speech signals over a duplex channel system.
Claim 21
Dependent Claim
26 words
A transceiver as claimed in claim 18, characterized in that said transceiver is arranged to communicate with a primary station by single frequency time division duplex.
Claim 22
Dependent Claim
38 words
A transceiver as claimed in claim 19, characterised in that each channel comprises two slots and the message structure for each slot comprises successively a preamble, a training sequence, a signalling field, a data field and tail bits.
Claim 23
Dependent Claim
34 words
A transceiver as claimed in claim 19, characterised in that the primary and secondary stations each operate in accordance with a protocol which permits either station to initiate a call to the other station.
Claim 24
Dependent Claim
17 words
A transceiver as claimed in claim 18 characterised in that the modulation parameter (bandwidth×time) BT is 0.3.
Claim 25
Dependent Claim
50 words
A transceiver as claimed in claim 18, for responding to a signalling protocol comprising a physical layer, a link layer and network layer protocols, characterised in that at least some of the signalling messages for the link layer comprise short form messages which are contained in a single message frame.
Claim 26
Dependent Claim
64 words
A transceiver as claimed in claim 18, characterized in that said transceiver comprises means for operating in a DECT system mode, said single means for modulating comprising means for setting the modulation rate to 1.152 Mbits/S, and said single means for formatting comprising means for setting the multiplexing rate to 12 duplex channels in a 10 mS frame, and for selecting the appropriate protocol.
References Cited (Backward Citations)
US4989230A
Cited
US5117449A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-05-17 | 1996-11-16 | 1997-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-05-17 | 2000-11-16 | 2001-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-05-17 | 2004-11-16 | 2005-05-18 | $7700.00 | Window Closed / Lapsed |