Patent US5969842A successfully refreshed from Google Patents.
US5969842A
Expired / Lapsed
US
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Method and apparatus for cordless infrared communication
Assignee: Wireless Communications Products LLC
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Filing: 1998-02-17
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Granted: 1999-10-19
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Expires: 2018-02-17
Abstract
Abstract An infrared (IR) communication system is described in which a base unit for a cell can communicate with a plurality of infrared portable devices through distributed infrared receiver/transmitter (RT) modules over a plurality of channels using IR carrier signals. A call or signal processor, referred to as a radio exchange unit, and controlling communication of a cell, communicates with the base unit to place or receive calls with the IR portable devices. The communication occurs in standard communication frames divided into transmission and receiving segments with each segment further divided into slots and with the slots containing digital data, with each communication-channel formed by a slot. Each transmission segment to an RT module is immediately followed by a responsive receiving segment. As an IR portable device moves from the vicinity of one RT module to another, the base unit automatically and seamlessly and in a robust manner hands over control to the nearer RT module by monitoring signal strength signals from various RT modules coupled to the base unit. When an IR portable device moves from one cell to another, the call processor hands over control to another base unit using standard protocols. Since an IR portable device may receive IR communication signals from several RT modules, care is taken to avoid signal interference by effectively controlling signal propagation lengths between the base unit and RT modules so that signals arriving from nearby RT modules at a common IR portable device do not have a phase difference more than a predetermined amount. The path lengths can be controlled by selecting cable lengths or by insertion of delays between the base unit and the RT modules to assure that IR signals arrive at portable devices with a minimum amount of interference.
Inventors
- 👤 James W. Crimmins
- 👤 James L. Saulnier
- 👤 Steven Gallo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:40
CPC Classifications
H; H04; H04B; H04B10/00; H04B10/11; H04B10/114; H04B10/1149
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
172 words
An infrared receiver/transmitter (RT) module for use in a communication system using a time division multiple access communication protocol for enabling a central control unit connected to telephone lines to communicate with a plurality of portable infrared devices located within a building through a signal processing unit which produces a repetitive frame signal having time spaced transmission and receiving segments each of which includes a plurality of time spaced respective transmission and receiving slots, comprising: an infrared, receiver and transmitter (RT) module, said RT module including means for sending signals received from a base unit within transmission slots at an infrared carrier frequency to portable infrared devices and means for sending signals received in the form of infrared signals from portable devices within receiving slots to the base unit; said RT module including a signal generator to produce characteristic signals indicative of a quality of infrared signals occurring during respective receiving slots and incident at the RT module from infrared portable devices communicating during said respective receiving slots with the base unit.
Claim 2
Dependent Claim
172 words
An infrared receiver/transmitter (RT) module for use in a communication system using a time division multiple access communication protocol for enabling a central control unit connected to telephone lines to communicate with a plurality of portable infrared devices located within a building through a signal processing unit which produces a repetitive frame signal having time spaced transmission and receiving segments each of which includes a plurality of time spaced respective transmission and receiving slots, comprising: an infrared, receiver and transmitter (RT) module, said RT module including means for sending signals received from a base unit within transmission slots at an infrared carrier frequency to portable infrared devices and means for sending signals received in the form of infrared signals from portable devices within receiving slots to the base unit; said RT module including a signal generator to produce characteristic signals indicative of a quality of infrared signals occurring during respective receiving slots and incident at the RT module from infrared portable devices communicating during said respective receiving slots with the base unit.
Claim 3
Dependent Claim
231 words
An infrared receiver/transmitter (RT) module for use in a communication system using a time division multiple access communication protocol for enabling a central control unit connected to telephone lines to communicate with a plurality of portable infrared devices located within a building through a signal processing unit which produces a repetitive frame signal having time spaced transmission and receiving segments each of which includes a plurality of time spaced respective transmission and receiving slots, comprising: an infrared, receiver and transmitter (RT) module, said RT module including means for sending signals received from a base unit within transmission slots at an infrared carrier frequency to portable infrared devices and means for sending signals received in the form of infrared signals from portable devices within receiving slots to the base unit; said RT module including a signal strength detector to produce characteristic signals indicative of the strength of infrared signals occurring during respective receiving slots and incident at the RT module from infrared portable devices communicating during said respective receiving slots with the base unit; means for producing a reference signal indicative of a high quality infrared signal level incident on the RT module; and means responsive to the reference signal and a signal representative of the infrared signal incident on the RT module for producing said characteristic signals when said infrared signals incident on the RT module exceed the reference signal level.
Claim 4
Dependent Claim
231 words
An infrared receiver/transmitter (RT) module for use in a communication system using a time division multiple access communication protocol for enabling a central control unit connected to telephone lines to communicate with a plurality of portable infrared devices located within a building through a signal processing unit which produces a repetitive frame signal having time spaced transmission and receiving segments each of which includes a plurality of time spaced respective transmission and receiving slots, comprising: an infrared, receiver and transmitter (RT) module, said RT module including means for sending signals received from a base unit within transmission slots at an infrared carrier frequency to portable infrared devices and means for sending signals received in the form of infrared signals from portable devices within receiving slots to the base unit; said RT module including a signal strength detector to produce characteristic signals indicative of the strength of infrared signals occurring during respective receiving slots and incident at the RT module from infrared portable devices communicating during said respective receiving slots with the base unit; means for producing a reference signal indicative of a high quality infrared signal level incident on the RT module; and means responsive to the reference signal and a signal representative of the infrared signal incident on the RT module for producing said characteristic signals when said infrared signals incident on the RT module exceed the reference signal level.
Claim 5
Dependent Claim
257 words
An infrared receiver/transmitter (RT) module for use in a communication system using a time division multiple access communication protocol for enabling a central control unit connected to telephone lines to communicate with a plurality of portable infrared devices located within a building through a signal processing unit which produces a repetitive frame signal having time spaced transmission and receiving segments each of which includes a plurality of time spaced respective transmission and receiving slots, comprising: an infrared, receiver and transmitter (RT) module, said RT module including first means for sending signals received from a base unit within transmission slots at an infrared carrier frequency to portable infrared devices and second means for sending signals received in the form of infrared signals from portable devices within receiving slots to the base unit; said RT module including a signal generator, which produces characteristic signals indicative of a quality of infrared signals occurring during respective receiving slots and incident at the RT module from infrared portable devices communicating during said respective receiving slots with the base unit; means for producing a reference signal indicative of an acceptable quality infrared signal level incident on the RT module; means responsive to the reference signal and a signal representative of the infrared signal incident on the RT module for producing an enabling signal when said infrared signals incident on the RT module exceed the reference signal level; and means responsive to the enabling signal and an electrical form of the infrared signals incident upon the RT module for activating the second sending means.
Claim 6
Dependent Claim
257 words
An infrared receiver/transmitter (RT) module for use in a communication system using a time division multiple access communication protocol for enabling a central control unit connected to telephone lines to communicate with a plurality of portable infrared devices located within a building through a signal processing unit which produces a repetitive frame signal having time spaced transmission and receiving segments each of which includes a plurality of time spaced respective transmission and receiving slots, comprising: an infrared, receiver and transmitter (RT) module, said RT module including first means for sending signals received from a base unit within transmission slots at an infrared carrier frequency to portable infrared devices and second means for sending signals received in the form of infrared signals from portable devices within receiving slots to the base unit; said RT module including a signal generator, which produces characteristic signals indicative of a quality of infrared signals occurring during respective receiving slots and incident at the RT module from infrared portable devices communicating during said respective receiving slots with the base unit; means for producing a reference signal indicative of an acceptable quality infrared signal level incident on the RT module; means responsive to the reference signal and a signal representative of the infrared signal incident on the RT module for producing an enabling signal when said infrared signals incident on the RT module exceed the reference signal level; and means responsive to the enabling signal and an electrical form of the infrared signals incident upon the RT module for activating the second sending means.
Claim 7
Dependent Claim
63 words
The RT module as claimed in claim 1 wherein said signal generator further comprises: means for producing a control signal representative of the end of a preceding slot; and means activated by the control signal for generating a said characteristic signal indicative of a quality of the infrared signal incident on the RT module during a receiving slot which follows the preceding slot.
Claim 8
Dependent Claim
70 words
The RT module as claimed in claim 4 wherein said receiving signals sent in different slots during receiving segments are separated by short intervals of time; and wherein said characteristic signal generating means comprises a fast analog to digital converter coupled to produce a predetermined number of data bits representative of the signal strength or signal-to-noise ratio of the infrared signals incident on the RT module during the short intervals.
Claim 9
Dependent Claim
32 words
The RT module as claimed in claim 5 and further including means for sending the individual data bits from the fast analog to digital converter on separate lines to said base unit.
Claim 10
Dependent Claim
212 words
An infrared receiver/transmitter (RT) module for use in a communication system using a time division multiple access communication protocol for enabling a central control unit connected to telephone lines to communicate with a plurality of portable infrared devices located within a building through a signal processing unit which produces a repetitive frame signal having time spaced transmission and receiving segments each of which includes a plurality of time spaced respective transmission and receiving slots, comprising: an infrared, receiver and transmitter (RT) module, said RT module including means for sending signals received from a base unit within transmission slots at an infrared carrier frequency to portable infrared devices and means for sending signals received in the form of infrared signals from portable devices within receiving slots to the base unit; said RT module including a signal strength detector to produce characteristic signals indicative of the strength of infrared signals occurring during respective receiving slots and incident at the RT module from infrared portable devices communicating during said respective receiving slots with the base unit; and means for sensing a calibration mode and means responsive to the sensed calibration mode for returning signals to a base unit for a measurement of the length of a cable coupling the RT module to the base unit.
Claim 11
Dependent Claim
212 words
An infrared receiver/transmitter (RT) module for use in a communication system using a time division multiple access communication protocol for enabling a central control unit connected to telephone lines to communicate with a plurality of portable infrared devices located within a building through a signal processing unit which produces a repetitive frame signal having time spaced transmission and receiving segments each of which includes a plurality of time spaced respective transmission and receiving slots, comprising: an infrared, receiver and transmitter (RT) module, said RT module including means for sending signals received from a base unit within transmission slots at an infrared carrier frequency to portable infrared devices and means for sending signals received in the form of infrared signals from portable devices within receiving slots to the base unit; said RT module including a signal strength detector to produce characteristic signals indicative of the strength of infrared signals occurring during respective receiving slots and incident at the RT module from infrared portable devices communicating during said respective receiving slots with the base unit; and means for sensing a calibration mode and means responsive to the sensed calibration mode for returning signals to a base unit for a measurement of the length of a cable coupling the RT module to the base unit.
Claim 12
Dependent Claim
281 words
An infrared digital and analog communication system using a time division multiple access communication protocol for enabling a central control unit connected to telephone lines to communicate with a plurality of portable infrared devices located within a building through a signal processing unit which produces a repetitive frame signal having time spaced transmission and receiving segments each of which includes a plurality of time spaced respective transmission and receiving slots, a respective pair of which is, when needed to establish communication, designated to transmit and receive signals between a portable infrared device and a base unit, comprising: a base unit operatively located between the signal processing unit and the portable devices for enabling communication therebetween; a plurality of spaced apart stationary infrared receiver and transmitter (RT) modules, interposed between the base unit and said portable devices, for transmitting and receiving infrared signals at a desired carrier frequency to and from said portable devices; said RT modules each including a signal processor, which produces a characteristic signal representative that the intensity or the signal-to-noise ratio of IR carrier signals from portable devices incident on the respective RT module for each receiving slot exceeds a minimum threshold level; a receiving signal selector in the base unit, responsive to said characteristic signals from RT modules, to select a received signal from one of several RT modules which respond to an infrared portable device transmission for transfer of the selected received signal to said signal processing unit, whereby the system's IR connection to a portable infrared device can be effectively, automatically and instantly handed off from an RT module experiencing an unacceptable infrared input signal to an RT module having an acceptable infrared input signal.
Claim 13
Dependent Claim
281 words
An infrared digital and analog communication system using a time division multiple access communication protocol for enabling a central control unit connected to telephone lines to communicate with a plurality of portable infrared devices located within a building through a signal processing unit which produces a repetitive frame signal having time spaced transmission and receiving segments each of which includes a plurality of time spaced respective transmission and receiving slots, a respective pair of which is, when needed to establish communication, designated to transmit and receive signals between a portable infrared device and a base unit, comprising: a base unit operatively located between the signal processing unit and the portable devices for enabling communication therebetween; a plurality of spaced apart stationary infrared receiver and transmitter (RT) modules, interposed between the base unit and said portable devices, for transmitting and receiving infrared signals at a desired carrier frequency to and from said portable devices; said RT modules each including a signal processor, which produces a characteristic signal representative that the intensity or the signal-to-noise ratio of IR carrier signals from portable devices incident on the respective RT module for each receiving slot exceeds a minimum threshold level; a receiving signal selector in the base unit, responsive to said characteristic signals from RT modules, to select a received signal from one of several RT modules which respond to an infrared portable device transmission for transfer of the selected received signal to said signal processing unit, whereby the system's IR connection to a portable infrared device can be effectively, automatically and instantly handed off from an RT module experiencing an unacceptable infrared input signal to an RT module having an acceptable infrared input signal.
Claim 14
Dependent Claim
48 words
The infrared communication system as claimed in claim 8 wherein said RT module's signal processor produces a high quality signal indicative that the IR carrier signals from a portable device incident on the respective RT module for a respective receiving slot exceeds a predetermined high quality signal level.
Claim 15
Dependent Claim
43 words
The infrared communication system as claimed in claim 9 wherein said receiving signal selector in said base unit further includes a priority network responsive to respective high quality signals from different RT modules so as to select one of said high quality signals.
Claim 16
Dependent Claim
90 words
The infrared communication system as claimed in claim 8 and further including: a hub interposed between the base unit and a plurality of RT modules; said hub having a first port for connection to the base unit and a plurality of second ports for connection to a plurality of RT modules, said hub having an interconnection network between said first port and said second ports to enable communication between said portable devices and said base unit within said transmission and receiving slots as if the hub were an RT module.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-10-18 | 2003-04-19 | 2003-10-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-10-18 | 2007-04-19 | 2007-10-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-10-18 | 2011-04-19 | 2011-10-19 | $7700.00 | Window Closed / Lapsed |