(19) United States
`(12) Patent Application Publication (10) Pub. No.: US 2005/0113124 A1
`Syrjarinne et al.
`(43) Pub. Date:
`May 26, 2005
`
`US 20050113124A1
`
`(54) METHOD AND APPARATUS FOR
`LOWERING POWER USE BY A RANGING
`RECEIVER
`(76) Inventors: Jari Syrjarinne, Tampere (FI); Jani
`Kappi, Tampere (FI)
`Correspondence Address:
`WARE FRESSOLAWAN DER SLUYS &
`ADOLPHSON, LLP
`BRADFORD GREEN BUILDING 5
`755 MAIN STREET, PO BOX 224
`MONROE, CT 06468 (US)
`(21) Appl. No.:
`10/727,342
`(22) Filed:
`Nov. 26, 2003
`Publication Classification
`
`(51) Int. Cl. .................................................... H04B 7700
`
`(52) U.S. Cl. .............................................. 455/522; 455/69
`
`(57)
`
`ABSTRACT
`
`Equipment and a method by which power consumed by a
`ranging receiver (12) is reduced without appreciably impair
`ing performance of the GPS receiver (12), the method
`including: a step (21) in which a controller (15) reads Sensor
`Signals provided by a motion Sensor (14) mechanically
`coupled to the ranging receiver (12); and a step (22) in which
`the controller (15) powers down selected components of the
`ranging receiver (12) based on whether the Sensor Signals
`indicate only at most insubstantial motion of the ranging
`receiver (12). The motion Sensor is advantageously a motion
`Sensor constructed using MEMS technology, but at any rate
`is of a type using So little power as to provide a power
`Savings when used according to the invention, i.e. when it is
`always on and at least partially based on its Sensor Signals,
`the ranging receiver (12) is Sometimes at least partially
`turned off.
`
`- - - - - a- - - - - - - - - - - - - - -
`
`10 cellular phone
`
`12 GPS receiver
`
`
`
`14 Motion sensor
`
`
`
`15 Controller
`
`
`
`16 User interface
`
`1 Mobile terminal
`
`Exhibit 2006
`
`

`

`Patent Application Publication May 26, 2005
`
`US 2005/0113124 A1
`
`
`
`
`
`
`
`14 Motion sensor
`
`15 Controller
`
`
`
`
`
`
`
`16 User interface
`
`11 Mobile terminal
`
`am as
`
`as p an um m am ame sm amo ame m m ms um sm
`
`
`
`21 Read sensor Output
`signals and GPS receiver
`Output signals.
`
`ls motion significant?
`
`22 Power down selected
`components of GPS
`receiver.
`
`23 Read sensor output
`Signals.
`
`Time to re-apply power to
`powered-down Components
`of GPS receiver (according
`to One Or another
`predetermined rule)?
`
`24 Re-apply power to
`powered-down components
`of GPS receiver.
`
`FIG. 2
`
`Exhibit 2006
`
`

`

`US 2005/0113124 A1
`
`May 26, 2005
`
`METHOD AND APPARATUS FOR LOWERING
`POWER USE BY A RANGING RECEIVER
`
`TECHNICAL FIELD
`0001. The present invention pertains to the field of rang
`ing receivers, including GPS receivers. More particularly,
`the present invention pertains to Saving power in Such
`receivers.
`
`BACKGROUND ART
`0002 For a GPS receiver integrated into a cellular phone,
`power-consumption is an issue. Since only a limited Storage
`of energy is available, every module inside a cellular phone
`should consume as little power as possible. Besides the
`required cellular transmitter and receiver modules, cellular
`phones today often include a GPS receiver module, a
`Bluetooth receiver module, a WLAN module, and even a
`Caca.
`0003. There are several ways to reduce power consump
`tion in an electrical device; e.g. the device can be miniatur
`ized, modules/components can be Selected that consume leSS
`power, or modules in the device can be selectively shut
`down (partially or wholly). Shutting down a module, how
`ever, is really only viable if it is possible to maintain the
`same level of performance with the shut down/reduced
`power-on time.
`0004) Of the modules now often included in cellular
`phones, the GPS receiver consumes significant power. There
`are many generally known techniques for Saving power
`consumed by a GPS receiver (in a cellular phone or in a
`standalone application): Parts of the GPS receiver hardware
`can be shut down; for example, any exceSS channels not
`useful in tracking Satellites due to poor local constellation
`can be powered-down. The GPS receiver hardware can be
`run at a lower frequency. And the GPS receiver RF (radiof
`requency) front-end can be shut down and only the tracking
`loops at the DSP (digital signal processing) baseband run (to
`enable fast reacquisition). All of these methods, however,
`without more, can Sacrifice GPS receiver performance.
`0005 For saving power in a cellular phone generally, it is
`noted that U.S. Pat. No. 6,067,460 for a MOBILESTATION
`HAVING ENHANCED STANDBY MODE discloses using
`motion sensors or a GPS receiver (or other devices) to
`determine when a user of a cellular phone might not be
`moving (or moving only very slowly), in which case
`usually only after the user confirms both that the user is not
`moving and is not likely to be moving in the next Several
`minutes-the cellular phone stops making neighbor channel
`measurements for DCCH (dedicated control channel) rese
`lection, thereby Saving power.
`0006 What is still needed is a way to reduce power use
`by a GPS receiver-in either a standalone application or in
`a mobile phone-without a significant sacrifice of the GPS
`receiver's performance.
`
`DISCLOSURE OF THE INVENTION
`0007 Accordingly, in a first aspect of the invention, an
`apparatus is provided comprising a ranging receiver, for
`providing output Signals indicating information as to the
`position or motion of the ranging receiver, the apparatus
`characterized in that: the ranging receiver is responsive to
`
`power control Signals based on Sensor Signals indicating
`whether the ranging receiver is in motion, the power control
`Signals for powering on or off Selected components of the
`ranging receiver; and in that the apparatus further comprises:
`a motion Sensor, mechanically coupled to the ranging
`receiver, for providing the Sensor Signals.
`0008. In accord with the first aspect of the invention, the
`apparatus may also include a controller, responsive to the
`Sensor Signals, for providing the power control Signals So as
`to power down the Selected components of the ranging
`receiver if the Sensor Signals indicate that the ranging
`receiver is Substantially Stationary.
`0009. Also in accord with the first aspect of the invention,
`the controller may use the output signals from the ranging
`receiver to determine whether to power down the selected
`components of the ranging receiver.
`0010 Also in accord with the first aspect of the invention,
`the controller may re-apply power to the Selected compo
`nents as Soon as the motion Sensor indicates significant
`motion of the ranging receiver.
`0011. Also in accord with the first aspect of the invention,
`the controller may re-apply power to the Selected compo
`nents according to a predetermined rule allowing for the
`power to remain off for a predetermined time based option
`ally on recent past Sensor Signals, but at least as Soon as the
`motion Sensor indicates Significant motion of the ranging
`receiver.
`0012. Also in accord with the first aspect of the invention,
`the motion sensor may be a MEMS-based motion sensor.
`0013 Also in accord with the first aspect of the invention,
`the motion Sensor may comprise an electronic compass or an
`accelerometer.
`0014.
`In a second aspect of the invention, a system is
`provided including an apparatus according to the first aspect
`of the invention and also including one or more ranging
`Satellites for providing ranging Signals conveying navigation
`information, and the apparatus may provide the output
`Signals indicating information as to the position or motion of
`the ranging receiver based on the ranging Signals.
`0015. In a second aspect of the invention, a system is
`provided including a cellular communication terminal in
`turn including an apparatus according to the first aspect of
`the invention, and a cellular communication network by
`which the cellular communication terminal is communica
`tive with other communication terminals.
`0016. In a third aspect of the invention, a system is
`provided, comprising: a cellular communication terminal
`including an apparatus according to the first aspect of the
`invention; a cellular communication network by which the
`cellular communication terminal is communicative with
`other communication terminals, and one or more ranging
`Satellites for providing ranging Signals conveying navigation
`information, wherein the apparatus provides the output
`Signals indicating information as to the position or motion of
`the ranging receiver based on the ranging Signals.
`0017. In a fourth aspect of the invention, a method is
`provided for Saving power consumed by a ranging receiver,
`characterized by: a step of reading Sensor Signals provided
`by a motion Sensor mechanically coupled to the ranging
`
`Exhibit 2006
`
`

`

`US 2005/0113124 A1
`
`May 26, 2005
`
`receiver; and a step of powering down Selected components
`of the ranging receiver based on whether the Sensor Signals
`indicate only at most insubstantial motion of the ranging
`receiver.
`0.018. In accord with the fourth aspect of the invention,
`the method may also include: a step of reapplying power to
`the Selected components according to a predetermined rule
`allowing for the power to remain off for a predetermined
`time based optionally on recent past Sensor Signals, but at
`least as Soon as the motion Sensor indicates significant
`motion of the ranging receiver.
`0019. In a fifth aspect of the invention, a computer
`program product is provided comprising: a computer read
`able Storage Structure embodying computer program code
`thereon for execution by a computer processor, with Said
`computer program code characterized in that it includes
`instructions for performing the Steps of a method according
`to the fourth aspect of the invention.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`0020. The above and other objects, features and advan
`tages of the invention will become apparent from a consid
`eration of the Subsequent detailed description presented in
`connection with accompanying drawings, in which:
`0021
`FIG. 1 is a block diagram of a cellular phone
`including a GPS/ranging receiver, and also including a
`motion Sensor and a (power) controller, according to the
`invention.
`0022 FIG. 2 is a method by which the controller is
`operative.
`
`DETAILED DESCRIPTION OF THE
`INVENTION
`0023 The invention is described here in terms of a GPS
`receiver, but it should be understood that the invention
`applies to any kind of ranging receiver, i.e. any kind of a
`receiver equipped to wirelessly receive information useful in
`determining position or Velocity or another aspect of the
`motion or position of the receiver. For example, the inven
`tion applies also to ranging receivers used with GLONASS
`and receivers used with the Galileo positioning System
`(never abbreviated GPS-a planned satellite navigation sys
`tem intended as a European alternative to the United States
`Global Positioning System).
`0024. The invention is based on the following observa
`tions. A GPS receiver consumes ten-twenty times more
`power than current motion sensors based on MEMS (Micro
`electromechanical Systems) technology. A GPS receiver
`consumes Substantially more power when in active mode
`(i.e. actively acquiring Satellite or other ranging signals and
`recalculating position information) than when not in active
`mode, i.e. is in standby (during which the GPS receiver
`Simply holds in memory the last received ranging informa
`tion and position calculations). In addition, when the user of
`a cellular phone is in motion, the motion includes enough
`accelerations to be detectable by a low-power consuming
`MEMS-based motion sensor.
`0.025
`Based on these observations, and now referring to
`FIG. 1, to save power in a cellular phone 10 including a
`mobile terminal 11 (for communicating with a cellular
`
`telecommunication network via a radio access network) and
`also a GPS receiver/ranging receiver 12, a motion Sensor 14
`is included in the cellular phone mechanically (as opposed
`to electromagnetically) coupled (i.e. directly or indirectly
`attached) to the GPS receiver 12 (so as to sense the same
`motion as the GPS receiver 12) and signals provided by the
`motion sensor 14 are used by a controller 15 for deciding
`whether to Switch the GPS receiver 12 from active mode to
`Standby, or to otherwise turn off one or more components of
`the GPS receiver 12. The controller 15 may base its decision
`not only on the motion Sensor Signals, but also on the most
`recent position calculations by the GPS receiver 12. In
`normal operation, the GPS (receiver) 12 provides its posi
`tion calculations to a user interface module 16 (including
`typically Some form of display or other means by which to
`convey information to a user and means by which to accept
`inputs from the user).
`0026. The invention thus saves power by reducing
`power-on time of one or more components of the GPS
`receiver 12, components used in receiving and processing
`ranging Signals. And it does So in Such a way as to Still give
`a continuous periodic position result to the user because the
`power is turned off by the controller 15 only if inputs to the
`controller-from typically both the motion sensor 14 and the
`GPS-indicate that the mobile phone is likely stationary.
`0027. The motion sensor 12 is of course of a type that
`uses relatively low power So that Sometimes keeping the
`motion Sensor online and turning off Some of the compo
`nents of the GPS receiver and Sometimes keeping the motion
`Sensor online and also keeping the GPS receiver online is
`less power-costly than keeping the GPS in full active mode
`all the time. Preferably, the motion sensor (system) 12 uses
`one or more relatively low-power consuming embedded
`motion Sensors (not shown), Such as electronic compasses,
`accelerometers (Such as e.g. gyroscope-based accelerom
`eters and including angular accelerometers), and especially
`such motion sensors built using MEMS technology- i.e.
`MEMS-based motion sensors, which consume only about
`5-10% of the power that a typical GPS receiver consumes in
`active mode.
`0028. According to the invention in some embodiments,
`the power to the tracking components of the GPS receiver 12
`is shut down for a period of time (that may be interrupted if
`motion is sensed before the time period elapses) if both the
`GPS receiver and the motion sensor system 14 (one or more
`motion sensors) detect either Stationary or very slow motion
`(i.e. motion of no significant consequence, Such as less than
`Several centimeters per minute).
`0029. The GPS receiver 12 can be kept in standby mode
`(or otherwise partially turned off) according to several
`different possible rules: In one rule, it is kept in Standby as
`long as the motion Sensor (System) 14 does not detect
`motion. In another rule, it is kept in Standby for Some
`predetermined time period but not after the motion Sensor 12
`again Senses motion. Alternatively, the GPS receiver can be
`turned back on (i.e. can be turned from Standby or partial
`power down to full active mode) after a first predetermined
`time even if the motion Sensors do not Sense motion, and
`then, if both the motion sensor 14 and the GPS receiver 12
`indicate that the user Still has not moved and is not moving,
`the GPS receiver 12 can be turned off again for a next, longer
`predetermined time, and So on, for longer and longer time
`Exhibit 2006
`
`

`

`US 2005/0113124 A1
`
`May 26, 2005
`
`periods, preferably up to Some maximum, as a precaution
`against failure of the motion Sensor 14. The procedure in
`which the GPS receiver 12 is turned back on after a
`predetermined time even if the motion Sensor does not detect
`motion (but turned back on earlier if the motion Sensor does
`Sense motion) is likely preferable for most applications,
`Since it is simple and prudent.
`0030 Thus, referring now to FIG. 2, the invention pro
`vides a method having a first Step 21, in which the controller
`15 reads the output signals of the motion sensor 14 and the
`output signals of the GPS receiver 12. The controller then
`decides whether the there is significant motion indicated by
`the outputs. If so, then in a next step 22, the controller 15
`powers down selected components of the GPS receiver 12,
`typically simply switching the GPS receiver from active
`mode to Standby mode, although more Sophisticated Strate
`gies for partially shutting down the GPS receiver are also
`contemplated by the invention. Then (after Some predeter
`mined time) in a next step 23, the controller 15 again reads
`output signals from the motion sensor 14 (but not also from
`the GPS receiver, which is turned off at this point). This step
`may be repeated Several times in Succession. Eventually,
`after either Some predetermined time has elapsed according
`to e.g. a local clock 18, or as Soon as the motion Sensor 14
`indicates Significant motion, the controller 15 decides
`whether it is time to re-apply power to the powered-down
`components of GPS receiver according to one or another of
`the above-described (or comparable) rules, or Some combi
`nation of the above (or comparable) rules. If so, the in a next
`Step 24, the controller 15 re-applies power to the powered
`down components of GPS receiver 12.
`0031. In a typical application of the invention in case of
`a GPS receiver included in a cellular phone 10, the GPS
`receiver 12 is embedded in the cellular phone so as to be
`either integrated into the chip Set used by the phone or as a
`Separate chip Set, and, in addition, the motion Sensor (Sys
`tem), typically consisting of one or more individual motion
`Sensors, are integrated into the cellular phone on its printed
`wiring board (PWB) (also known as a printed circuit board),
`e.g. for gaming, UI control or other purposes.
`0032. As is clear from the above description, the inven
`tion is also of use in case of a GPS receiver not included as
`part of a cellular phone. In Such an application, the GPS
`receiver equipment proper (i.e. the core equipment of the
`GPS receiver, such as it would be without the invention) is
`included in a housing that also includes one or more motion
`Sensors and a controller, just as in the above description. And
`the controller is operative just as in the above description.
`Furthermore, using MEMS-based motion sensor technology
`or any other miniature motion Sensor equipment, many
`already-manufactured GPS receivers can be retrofit with a
`controller and a motion Sensor (System) So as to be operative
`according to the invention.
`0033. As another example of the use of the invention, it
`can be used with a so-called BlueTooth GPS module and
`especially Such a module included in a cellular telephone,
`i.e. Such a BlueTooth GPS module can be coupled to a
`motion Sensor So as to be powered on and off as described
`above.
`0034 AS explained above, the invention provides both a
`method and corresponding equipment consisting of various
`modules providing the functionality for performing the Steps
`
`of the method. The modules may be implemented as hard
`ware, or may be implemented as Software or firmware for
`execution by a processor. In particular, in the case of
`firmware or Software, the invention can be provided as a
`computer program product including a computer readable
`Storage Structure embodying computer program code-i.e.
`the Software or firmware-thereon for execution by a com
`puter processor.
`0035) It is to be understood that the above-described
`arrangements are only illustrative of the application of the
`principles of the present invention. Numerous modifications
`and alternative arrangements may be devised by those
`skilled in the art without departing from the Scope of the
`present invention, and the appended claims are intended to
`cover Such modifications and arrangements.
`
`What is claimed is:
`1. An apparatus, comprising a ranging receiver (12), for
`providing output Signals indicating information as to the
`position or motion of the ranging receiver (12), the apparatus
`characterized in that:
`the ranging receiver is responsive to power control signals
`based on Sensor Signals indicating whether the ranging
`receiver (12) is in motion, the power control Signals for
`powering on or off Selected components of the ranging
`receiver;
`and in that the apparatus further comprises:
`a motion Sensor (14), mechanically coupled to the ranging
`receiver (12), for providing the Sensor signals.
`2. An apparatus as in claim 1, further characterized by a
`controller (15), responsive to the Sensor Signals, for provid
`ing the power control Signals So as to power down the
`Selected components of the ranging receiver (12) if the
`Sensor signals indicate that the ranging receiver (12) is
`Substantially Stationary.
`3. An apparatus as in claim 1, wherein the controller (15)
`also uses the output signals from the ranging receiver (12) to
`determine whether to power down the Selected components
`of the ranging receiver (12).
`4. An apparatus as in claim 1, wherein the controller (15)
`re-applies power to the Selected components as Soon as the
`motion sensor (14) indicates significant motion of the rang
`ing receiver (12).
`5. An apparatus as in claim 1, wherein the controller (15)
`re-applies power to the Selected components according to a
`predetermined rule allowing for the power to remain off for
`a predetermined time based optionally on recent past Sensor
`Signals, but at least as Soon as the motion sensor (14)
`indicates significant motion of the ranging receiver (12).
`6. An apparatus as in claim 1, wherein the motion Sensor
`(14) is a MEMS-based motion sensor.
`7. An apparatus as in claim 1, wherein the motion Sensor
`(14) comprises an electronic compass or an accelerometer.
`8. A System, comprising: an apparatus as in claim 1, and
`further comprising one or more ranging Satellites for pro
`Viding ranging Signals conveying navigation information,
`wherein the apparatus provides the output signals indicating
`information as to the position or motion of the ranging
`receiver (12) based on the ranging signals.
`9. A System, comprising: a cellular communication ter
`minal including an apparatus as in claim 1, and a cellular
`
`Exhibit 2006
`
`

`

`US 2005/0113124 A1
`
`May 26, 2005
`
`communication network by which the cellular communica
`tion terminal is communicative with other communication
`terminals.
`10. A System, comprising: a cellular communication ter
`minal including an apparatus as in claim 1; a cellular
`communication network by which the cellular communica
`tion terminal is communicative with other communication
`terminals, and one or more ranging Satellites for providing
`ranging Signals conveying navigation information, wherein
`the apparatus provides the output signals indicating infor
`mation as to the position or motion of the ranging receiver
`(12) based on the ranging signals.
`11. A method for Saving power consumed by a ranging
`receiver (12), characterized by:
`a step (21) of reading Sensor Signals provided by a motion
`Sensor (14) mechanically coupled to the ranging
`receiver (12); and
`
`a step (22) of powering down selected components of the
`ranging receiver (12) based on whether the Sensor
`Signals indicate only at most insubstantial motion of the
`ranging receiver (12).
`12. The method of claim 11, further characterized by:
`a step (24) of reapplying power to the Selected compo
`nents according to a predetermined rule allowing for
`the power to remain off for a predetermined time based
`optionally on recent past Sensor Signals, but at least as
`Soon as the motion Sensor (14) indicates significant
`motion of the ranging receiver (12).
`13. A computer program product comprising: a computer
`readable Storage Structure embodying computer program
`code thereon for execution by a computer processor, with
`Said computer program code characterized in that it includes
`instructions for performing the Steps of the method of claim
`11.
`
`Exhibit 2006
`
`