United States Patent [19J
`Myllymaki et al.
`
`[54] POWER CONSUMPTION MONITOR AND
`ALARM FOR A MOBILE MEANS OF
`COMMUNICATION
`
`[75]
`
`Inventors: Kimmo Sakari Myllymiiki,
`Riippakoivuntie; Veli A. Santomaa,
`Kotitontuntie; Seppo Kalervo Kivela,
`Rinteentie, all of Finland
`
`[73] Assignee: Nokia Mobile Phones Limited, Espoo,
`Finland
`
`[21] Appl. No.: 08/916,832
`
`[22] Filed:
`
`Aug. 22, 1997
`
`[30]
`
`Foreign Application Priority Data
`
`Aug. 30, 1996
`
`[FI]
`
`Finland .................................... 963389
`
`Int. Cl.7 ..................................................... H04B 17/00
`[51]
`[52] U.S. Cl. ......................... 455/115; 455/423; 455/67.1;
`455/116; 455/117
`[58] Field of Search .............................. 455/226.1, 226.2,
`455/226.4, 234.2, 250.1, 115, 117, 126,
`127, 67.1, 69, 70, 129, 423
`
`[56]
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`4,593,409
`4,703,259
`5,091,919
`5,101,175
`5,109,538
`5,118,965
`5,123,031
`5,152,004
`5,204,643
`5,214,372
`5,230,091
`5,241,694
`5,276,917
`5,291,150
`5,313,661
`5,333,175
`5,392,464
`5,404,585
`5,432,473
`
`6/1986 Miller ...................................... 455/129
`10/1987 Berliner et al. ......................... 455/115
`2/1992 Kuisma ..................................... 375/60
`3/1992 Vaisanen ................................. 330/279
`4/1992 Ikonen et al. ............................. 455/89
`6/1992 Vaisanen et al.
`....................... 307/261
`6/1992 Kuisma ..................................... 375/60
`9/1992 Vaisanen et al.
`......................... 455/68
`4/1993 Verronen .. ... ... .... ... ... ... ... ... .... 333/81 R
`5/1993 Vaisanen et al.
`......................... 324/95
`7/1993 Vaisanen ................................... 455/88
`8/1993 Vaisanen et al.
`....................... 455/126
`1/1994 Vanhanen et al. ........................ 455/89
`3/1994 Saarnimo et al.
`...................... 330/279
`5/1994 Malmi et al. ........................ 455/232.1
`7/1994 Ariyavisitakul et al. ............... 455/423
`2/1995 Pakonen .................................. 455/115
`4/1995 Vimpari et al. ......................... 455/115
`7/1995 Mattila et al. .......................... 330/133
`
`I 1111111111111111 11111 1111111111 1111111111 11111 1111111111 lll111111111111111
`US006018646A
`[11] Patent Number:
`[45] Date of Patent:
`
`6,018,646
`Jan.25,2000
`
`5,434,537
`5,450,620
`5,493,255
`5,530,923
`5,548,616
`5,564,074
`5,564,084
`5,564,086
`5,590,415
`5,604,921
`5,943,609
`
`7/1995 Kukkonen ................................... 330/2
`9/1995 Vaisanen ................................. 455/127
`2/1996 Murtojarvi .............................. 330/296
`6/1996 Heinonen et al.
`...................... 455/126
`8/1996 Mucke et al. ........................... 375/295
`10/1996 Juntti ...................................... 455/67.1
`10/1996 Hirasawa ................................ 455/115
`10/1996 Cygan et al.
`........................... 455/126
`12/1996 Peltola et al. ........................... 455/115
`2/1997 Alanara ..................................... 455/45
`8/1999 Ericson et al. ......................... 455/67.4
`
`FOREIGN PATENT DOCUMENTS
`
`92766 12/1994 Finland .
`2277234 10/1994 United Kingdom .
`PCT/SE95/
`00174
`WO 95/24059
`
`9/1995 WIPO .................................... 455/561
`9/1995 WIPO .
`
`OTHER PUBLICATIONS
`
`Patent Abstracts of Japan, Publication No. 08029462 A,
`Yoshimura Koji, "Reflected Wave Monitoring Device".
`
`Primary Examiner-Dwayne D. Bost
`Assistant Examiner-Joy Redmon
`Attorney, Agent, or Firm-Perman & Green, LLP
`
`[57]
`
`ABSTRACT
`
`The invention relates to portable mobile communication
`device. The system according to the invention measures the
`power transmitted by the mobile communication device and
`the reflected power returning from the antenna. From these,
`the system calculates various parameters, for example, the
`short-term average value, the cumulative sum of transmitted
`power used during a call and the proportion of power
`reflected back. The user may set the limit values which he
`requires for these parameters, and the system will issue an
`alarm when these are exceeded. If the user so desires, the
`system may also continuously display the value of a desired
`quantity. With the aid of the system according to this
`invention, the user may monitor the benefit of different
`positions and ways in which the appliance is used and the
`power consumption of the mobile communication device in
`different situations, and thus avoid unfavorable operating
`situations and methods.
`
`4 Claims, 2 Drawing Sheets
`
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`U.S. Patent
`
`Jan.25,2000
`
`Sheet 1 of 2
`
`6,018,646
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`U.S. Patent
`
`Jan.25,2000
`
`Sheet 2 of 2
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`6,018,646
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`6,018,646
`
`1
`POWER CONSUMPTION MONITOR AND
`ALARM FOR A MOBILE MEANS OF
`COMMUNICATION
`
`5
`
`2
`reflected radio power returning from the mobile commu(cid:173)
`nication means antadio power fed to the mobile com(cid:173)
`munication means antenna, and
`reflected radio power returning from the mobile commu-
`nication means antenna, and by the fact that the system
`is designed to alarm the user of the mobile communi(cid:173)
`cation means of a manner of usage in which the radio
`power consumption of the mobile communication
`means exceeds a preset limit.
`The system according to this invention measures the
`power transmitted by the mobile communication means and
`the reflected power returning from the antenna as a function
`of time. From these the system calculates different
`parameters, for example the short-term average value, the
`15 cumulative sum of transmitted power used during a call and
`the ratio of transmitted to reflected power. The user may
`determine his desired limit values for these, and when these
`limit values are exceeded the system will issue an alarm
`concerning this. If the user so desires, the system may also
`20 continuously indicate the value of a desired quantity. With
`the aid of the system according to this invention, the user
`may monitor the suitability of different positions and modes
`of use and the power consumption of the mobile commu(cid:173)
`nication means in different situations, and thus avoid
`25 unfavourable situations and modes of use.
`
`BACKGROUND OF THE INVENTION
`This invention relates to mobile means of communication,
`and in particular to the ways and situations in which they are
`used.
`In the most common mobile communication means
`systems, the base station controls the transmitted power of 10
`the mobile communication means on the basis of the
`received signal level. The transmitted power of a mobile
`communication means close to the base station is small,
`whereas at the limits of the coverage area the transmitted
`power is at its maximum. The current consumption of a
`mobile communication means is thus highly dependent upon
`the place in which the device is used.
`Different obstacles, particularly in the immediate vicinity
`of the antenna, also attenuate the transmitter signal. The base
`station compensates for this attenuation by increasing the
`transmitted power of the mobile communication means. For
`example, a poor operating position of the mobile commu(cid:173)
`nication means, or having the antenna too close to the user's
`head, may cause an unnecessary rise in the current con(cid:173)
`sumption. The same problem also arises when the user has
`turned so that his head lies between the base station and the
`mobile communication means.
`A third factor affecting the intensity of the signal received
`
`DESCRIPTION OF THE DRAWING
`
`Below, the invention will be described in greater detail
`with reference to favourable embodiments, which are pre(cid:173)
`sented by way of example, and to the attached drawings,
`where
`FIG. 1 shows a system according to the prior art for
`measuring the power fed to an antenna and the reflected
`power returning therefrom,
`FIG. 2 shows the circuitry of a detector according to the
`prior art for power coming from a directional coupler, and
`FIG. 3 shows an example of a system according to the
`present invention.
`In the drawings, the same reference numbers and symbols
`are used for parts which correspond to one another.
`
`DETAILED DESCRIPTION OF THE
`INVENTION
`
`35
`
`:'o~t: !::m~~I~:~i;: !eea:t~~~~a~~ :~:iii:t::t:~n°a~ :~: 30
`typically arranged so as to transmit and receive vertically
`polarized signals, in which case the signal received by the
`base station is at its most powerful when the antenna of the
`mobile communication means is in the vertical position. If
`the user holds the mobile communication means diagonally
`or even horizontally, the signal received by the base station
`is thereby weakened, in which case the base station has
`again to increase the transmitted power.
`An object of this invention is to create a system which 40
`directs the user of a mobile communication means to use his
`device in an optimal way. An object of this invention is also
`to create a system with the aid of which the user may avoid
`or shorten the length of a call when the power consumption
`of the mobile communication means is high. A further object 45
`of the invention is to create a system with the aid of which
`the user may maximize the battery charging interval. An
`object of the invention is also to create such a system with
`as little alteration as possible to current mobile telephones.
`
`SUMMARY OF THE INVENTION
`The objects of the invention are attained by monitoring
`the power fed to the antenna and the reflected power
`returning from the antenna, and by informing the user of
`these in the way desired by the user. The amount of power
`fed to the antenna immediately reveals the level of current
`consumption by the mobile communication means. Objects
`close to the antenna cause reflection of power back, in which
`case a high level of reflected power indicates that the
`antenna is, for example, too close to the user's head.
`This invention is characterized by the fact that it com-
`prises
`a detector of power fed to the antenna,
`a detector of reflected power returning from the antenna,
`a control device,
`at least one alarm device and by the fact that the system
`is designed to monitor
`
`FIG. 1 shows a system according to the prior art for
`measurement of the outgoing and reflected power, which
`may advantageously also be used in the system according to
`this invention. The directional coupler 2 is situated in the
`50 transmission line between the output stage of the transmitter
`and the antenna. The directional coupler comprises, in
`addition to the transmission line connectors, two outputs, the
`signal level of the first of which is proportional to the signal
`power going to the antenna from the output stage, and the
`55 signal level of the second of which is proportional to the
`signal power going from the antenna to the output stage.
`These outputs are connected to detectors 8, 10 at the outputs
`of which there is a DC voltage U ant proportional to the
`power going to the antenna and a DC voltage Ure/ propor-
`60 tional to the power going to the output stage. FIG. 2 shows
`the circuitry of a detector 8, 10 according to the prior art
`which is suitable for the system according to this invention.
`The operation of this detector is described in greater detail
`in the Finnish Patent 82865 and in the corresponding U.S.
`65 Pat. No. 5,214,372. In the system according to the present
`invention use may also be made of any other measuring- and
`detection circuitry according to the prior art.
`
`4
`
`

`

`6,018,646
`
`3
`In mobile means of communication according to the prior
`art it is typically only the transmitted power which is
`measured for regulation of the power output, in which case
`detector 10 in the measuring circuit according to FIG. 1 is
`usually replaced by a resistor. In the system according to the
`present invention it is essentially the power in both direc(cid:173)
`tions which is measured.
`FIG. 3 shows one embodiment of the system according to
`the present invention. The outputs of the detectors 8, 10 in
`the system according to this invention are connected to a 10
`control circuit 26, which may for convenience be the micro(cid:173)
`processor 26 controlling the operation of the mobile com(cid:173)
`munication means. The system may also include signal
`processing devices, which calculate various parameters on
`the basis of the output signals of the detectors, such as, for
`example, the short-term average value, the cumulative sum 15
`of transmitted power used during a call and the ratio of
`transmitted to reflected power. These signal processing
`devices may conveniently be realized as programmes of the
`control circuit 26. The control circuit 26 monitors the
`transmitted and the reflected power and the parameters
`calculated from these by the signal processing devices 20,
`22, 24. Control circuit 26 may transmit to the user informa(cid:173)
`tion as to the values of these quantities or as to whether the
`set limits are exceeded, for example with the aid of the
`display 28, a light-emitting diode 30, a loudspeaker or
`similar device 32 or a vibrator 34. The user may set the
`limits he requires for different quantities, for example with
`the aid of the keypad 36 of the mobile communication
`means.
`In another favourable embodiment of this invention the 30
`signal processing devices 20, 22, 24 are realized program(cid:173)
`matically as a programme of the microprocessor 26. In that
`case, the output signal of detectors 8, 10 has to be converted
`to digital form with an analog/digital converter, after which
`the processor 26 may carry out the necessary signal pro-
`cessing operations.
`The system according to this invention may transmit
`information as to the value of the quantities and as to
`whether limits are exceeded, for example by a visual signal,
`an acoustic signal or a mechanical signal. The visual signal
`may for example take the form of a light-emitting diode 30
`or a symbol shown on the display 28 of the mobile com(cid:173)
`munication means, which the system illuminates when a
`specific limit is exceeded.
`With the aid of the display 28 it is possible to produce a
`wide selection of different indications; the indicator may for
`example be a symbol, text or the numerical value of a
`particular quantity.
`With the mobile communication means loudspeaker 32, 50
`earpiece 32 or corresponding device it is possible to create
`various acoustic signals. When the limit value of a given
`quantity is exceeded, the system may issue an acoustic
`signal, or the value of a desired quantity may be transmitted
`to the user as a quiet acoustic signal, the frequency of which 55
`is dependent upon the value of the quantity. Such a signal
`should ideally be so quiet that it does not disturb the user's
`call, in which case the user may, by monitoring the pitch of
`the signal tone during the call, find a more favourable call
`location or a better operating position. The vibratory alarm 60
`of the mobile communication means may also act as the
`alarming device in the system according to this invention.
`With the system according to this invention it is possible
`to monitor a wide selection of quantities in addition to
`directly measured transmitted and reflected power.
`The short-term average value is in many cases a quantity
`more useful than the measured instantaneous power, since
`
`4
`rapid changes in power caused by momentary variations in
`signal strength occurring, for example, when the user is
`moving, do not in that case immediately result in an alarm.
`Another useful monitored quantity is the cumulative sum of
`5 power used during a call, with the aid of which the user may
`set for each call the the upper limit of used power which he
`desires. In this way the user may be warned of situations in
`which the battery of the mobile communication means
`discharges rapidly.
`In many situations, the ratio of transmitted to reflected
`power is a quantity more useful than reflected power alone,
`since the amount of transmitted power directly affects the
`reflected power. The power ratio best describes the condition
`of the antenna and the effect of objects close to the antenna
`on the signal. As the proportion of reflected power increases,
`the system may issue an alarm indicating that an object is too
`close to the antenna.
`The quantity of reflected power alone is a useful moni(cid:173)
`tored quantity if the user desires to reduce to a minimum the
`20 SAR value or the quantity of radio-frequency radiation
`directed at his body, as the amount of power reflected from
`the body is dependent upon the same factors as the quantity
`of radiation directed at the body: the transmitted power and
`the distance of the antenna from the body. For monitoring of
`25 the quantity of radio-frequency radiation directed at the
`body, the system may also incorporate a proximity sensor to
`measure the distance between the mobile communication
`means antenna and the body of the user. In a favourable
`embodiment of the invention the system may automatically
`reduce the outgoing power or interrupt transmission, if the
`quantity of reflected power exceeds a desired limit value, in
`which case the user does not need to monitor the system's
`indications.
`A third useful calculated quantity is the peak value of
`power or of some other above-mentioned quantity which has
`occurred during a specific period of time, since with the
`customary models of mobile communication means the user
`does not look at the display of the mobile communication
`40 means during a call. With the aid of such a peak value
`quantity the user may however monitor power peaks occur(cid:173)
`ring during a call.
`In the system according to this invention, the user may
`adjust the alarming limits and types of alarm in various ways
`45 advantageously with the aid of the keypad 36 and display 28
`of the mobile communication means. The user may select
`the quantities which he desires, set the alarming limits which
`he desires and choose the type of alarm which he requires.
`For example, the user may choose to have the short-term
`average value of transmitted power continuously visible on
`the display of the mobile communication means, and set an
`alarming limit on reflected power, and choose the type of
`alarm as a quiet acoustic signal which does not disturb his
`call. The user may also, if he so desires, prevent the issuing
`of all alarms.
`With the aid of the system according to the invention, the
`user may control the power consumption of the mobile
`communication means. This is particularly useful in circum(cid:173)
`stances in which the user does not have the opportunity to
`recharge the batteries of the mobile communication means,
`in which case the user will want to retain the battery capacity
`for as long as possible. In an optimal situation, in a good
`receiving area, the current consumption is at its lowest while
`the quality of the link is at its best. The system according to
`65 this invention also detects faults occurring in the antenna,
`since deficiency in the antenna increases the ratio of
`reflected power to outgoing power. With the aid of the
`
`35
`
`5
`
`

`

`6,018,646
`
`5
`system according to the invention the user may also reduce
`to a minimum the SAR value and the quantity of radiation
`directed at his head or body by employing the correct
`appliance positions and situations and by adjusting the
`transmission time.
`The system according to this invention is easy to incor(cid:173)
`porate in current mobile communication means, since for
`implementation of the invention use may be made of a
`directional coupler and transmitted power detector which are
`usually already present in current mobile communication 10
`means, so that only a detector of reflected power needs to be
`added to the mobile communication means. In a typical
`mobile communication means there are also a keypad and a
`display, which means that the control functions of the system
`according to this invention may be performed pro(cid:173)
`grammmatically making use of the microprocessor of the
`mobile communication means.
`We claim:
`1. A system for monitoring the consumption of power in
`a mobile communications device during use, wherein said
`device comprises a transmitter, a receiver, and an antenna
`connected thereto, said device controlled by a
`microprocessor, said system comprising:
`a first monitor for sensing the power level of the signal
`from the transmitter to the antenna during use;
`a second monitor for sensing the power level of the signal
`from the antenna to the receiver during use;
`a processing module within the microprocessor con(cid:173)
`structed to receive the transmitted signal power level
`and the received signal power level and calculate an
`average value of power consumption over a selected
`time;
`
`5
`
`6
`a storage module within the microprocessor for receiving
`and storing preset limits for said average power con(cid:173)
`sumption; and
`wherein said processing module compares said actual
`power consumption to said preset limit and generates
`an indication lo the user of the mobile communications
`device when said average power consumption exceeds
`said limits, to allow the user to adjust the use of the
`communication device to lower power consumption.
`2. A system for monitoring the consumption of power in
`a mobile communications device during use, wherein said
`device comprises a transmitter, a receiver, and an antenna
`connected thereto, said device controlled by a
`microprocessor, said system, as described in claim 1, further
`15 comprising an input device which enables the user to enter
`said preset limits in accordance with personal preference.
`3. A system for monitoring the consumption of power in
`a mobile communications device during use, wherein said
`device comprises a transmitter, a receiver, and an antenna
`20 connected thereto, said device controlled by a
`microprocessor, said system, as described in claim 1,
`wherein the processing module is constructed to calculate
`the cumulative sum of the power consumption during a call.
`4. A system for monitoring the consumption of power in
`25 a mobile communications device during use, wherein said
`device comprises a transmitter, a receiver, and an antenna
`connected thereto, said device controlled by a
`microprocessor, said system, as described in claim 1,
`wherein the processing module generates a continuous indi-
`30 cation of power consumption during use of the communi(cid:173)
`cations device.
`
`* * * * *
`
`6
`
`