Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W52/00—Power management, e.g. Transmission Power Control [TPC] or power classes
  • H04W52/02—Power saving arrangements
  • H04W52/0209—Power saving arrangements in terminal devices
  • H04W52/0261—Power saving arrangements in terminal devices managing power supply demand, e.g. depending on battery level
  • H04W52/0267—Power saving arrangements in terminal devices managing power supply demand, e.g. depending on battery level by controlling user interface components
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
  • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
  • H02J7/0063—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with circuits adapted for supplying loads from the battery
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
  • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
  • H02J7/007—Regulation of charging or discharging current or voltage
  • H02J7/00712—Regulation of charging or discharging current or voltage the cycle being controlled or terminated in response to electric parameters
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
  • H02J9/00—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting
  • H02J9/005—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting using a power saving mode
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
  • Y02D30/00—Reducing energy consumption in communication networks
  • Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks

Definitions

• the present invention relates generally to the field of communications and particularly to wireless telephones.
• Cordless or wireless telephones are typically home units that consist of a base unit and one or more remote units.
• An example of such a cordless telephone is seen in U.S. Patent No. 4,989,230 to Gillig et al., assigned to Motorola, Inc., and is incorporated herein by reference.
• the remote units communicate with the base unit over radio frequencies (RF) typically within a range of 1000 feet of the base unit.
• RF radio frequencies
• the base unit is connected to the land-line telephone system, thus al ⁇ lowing a remote user to communicate with other land-line telephones.
• the remote unit in order to conserve power, leaves the receiver in a power off state, applying power periodically for a brief period.
• the receiver is powered up in order to check for a depressed key on the keypad or an incoming ring signal from the base unit, since the remote unit has the alert transducer to announce an incoming call.
• the receiver draws a large amount of power from the remote's bat ⁇ tery, thus reducing the amount of time the remote can be used for a telephone call. There is a resulting need for way to re ⁇ cute the power used by the remote unit when not in a tele- phone call.
• the process of the present invention conserves battery power for a wireless communication device.
• the device has receiving means, data entry means, and a battery saver switch for enabling a power conservation mode or a normal mode.
• the process consists of first determining which mode the battery saver switch is enabling. If the normal mode is enabled, power is periodically applied to the receiving means and the data entry means is scanned for a depressed key. If the power conservation mode is enabled, the data entry means is scanned periodically for a depressed key while the receiving means remains in an unpowered state.
• FIG. 1 shows a block diagram of a base unit of a cord ⁇ less telephone.
• FIG. 2 shows a block diagram of a remote unit of a cord- less telephone.
• FIG. 3 shows a flowchart of the process for enabling a scrambling demonstration mode.
• FIG. 4 shows a block diagram of a scrambler integrated circuit.
• FIG. 5 shows a flowchart of the power saving process of the present invention.
• FIG. 6 shows a block diagram of a battery saver circuit of the present invention.
• the process of the present invention reduces the time that power is being used by the remote unit's receiver. By placing a switch in the power conservation mode position, the receiver is not turned on periodically as in the normal mode, thus reducing power consumption.
• FIG. 1 illustrates a preferred em ⁇ bodiment of a cordless telephone base unit having a control ⁇ lable scrambling or encryption circuit for encrypting and de- crypting signals.
• This particular base unit also includes a speakerphone.
• FIG. 2 illustrates a preferred embodiment of a remote unit for communicating with the base unit, the remote also having a controllable scrambling or encryption circuit for encrypting and decrypting signals.
• the base unit is comprised of an an- tenna (101) that is coupled to the receive and transmit paths of the base.
• the receive path is comprised of a bandpass filter (102) that allows the frequencies of 49.670 - 49.990 MHz to pass.
• the filter is connected to a receive amplifier (103) that ampli ⁇ fies the filtered signal by approximately 18 dB.
• the output of the amplifier is then filtered by another bandpass filter (104) before being input to the receiver (105).
• the preferred em ⁇ bodiment/the receiver is an MC3363 available from Motorola, Inc.
• the receiver (105) mixes the signal down to 10.7 MHz and then to 455 kHz. This signal is then demodulated.
• the lo ⁇ cal oscillators in the receiver (105) are controlled by a phase locked loop (120) whose frequency is controlled by a micropro ⁇ cessor (112).
• the microprocessor (112) also receives a carrier detect signal and the demodulated signal, labeled RX Data, from the receiver (105).
• the demodulated signal is used by the microprocessor (112) to interpret coded data messages trans ⁇ mitted by the remote unit. These coded data messages are used for DTMF dialing, telephone hook switch control, and control of the scrambling circuit.
• the carrier detect signal is used to detect the presence of a transmitter occupying the base unit receive channel.
• the mi ⁇ croprocessor (112) is an MC68HCL05C4 available from Motorola, Inc.
• the output of the receiver (105) is filtered again by an- other bandpass filter (106).
• the output of the filter (106) is in ⁇ put to the scrambling circuit (107).
• the scrambling circuit (107) is an MX108DW Full- Duplex Voiceband Scrambler integrated circuit available from MX • Com, Inc.
• the unscrambled output of the scrambler circuit (107) is filtered in a de-emphasis filter (108) before being input to an expander (109).
• the expansion process applies gain to the in ⁇ put signal that is varied as a function of the signal magnitude. The effective gain being greater for large magnitude signals and less for small magnitude signals.
• this signal After this signal has been filtered by a highpass filter (110), it is input to a speaker- phone circuit (111) and is also output to the land-line telephone system. If the speakerphone is being used, such as in a three way call between the base, the remote, and a land-line party, the audio signal is output to the base unit's speaker.
• the transmit path of the -base is comprised of the audio signal, either from the microphone (121) of the speakerphone or the land-line party, being bandpass filtered (113) before go ⁇ ing through a compressor (114).
• the compressor (114) applies gain to the audio signal that is varied as a function of the sig- nal magnitude, the effective gain being greater for small sig ⁇ nals.
• An example of a compandor compressor/expander
• the dynamic range of the compandor is 80 dB.
• the output of the compressor (114) is input to a pre-em- phasis filter (115) before being scrambled by the scrambler cir ⁇ cuit (116).
• the scrambler circuit (116) is the second half of the same integrated circuit used to unscramble the received sig ⁇ nal.
• the scrambled audio signal is bandpass filtered (117) be ⁇ fore being modulated by the transmitter (118) to a frequency in the range of 46.610 - 46.970 MHz.
• the actual frequency used by the telephone can. be user selectable by a switch or other con ⁇ trol on the telephone base or remote. Both the receive and transmit frequency ranges are set by the FCC for all cordless telephones.
• An example of a transmitter is MC2833 manufac- tured by Motorola, Inc.
• the output of the transmitter is bandpass filtered (119) to filter out the signal outside the 46.610 - 46.970 MHz range.
• This signal is then transmitted from the antenna (101) to the remote unit.
• the remote unit is comprised of the antenna (201) that receives the signal from the base unit.
• a bandpass filter (202) removes that part of the signal outside the range of 46.610 - 46.970 MHz.
• a gain of approximately 18 dB is then applied to the signal by a receive amplifier (203) before it is bandpass fil ⁇ tered (204) again. This signal is then input to the receiver (205).
• the remote unit receiver (205) mixes the signal down to 10.7 MHz and then to 455 kHz. This signal is then demodu ⁇ lated.
• the demodulated signal labeled RX Data, is input to the microprocessor (212) to interpret the coded data messages transmitted by the base unit. These coded data messages are used to control the remote ringer and the scrambling circuit.
• the demodulated signal is also bandpass filtered (206) before being input to the scrambler circuit (207) for descram- bling.
• the scrambler circuit (207) is identical to the integrated circuit used in the base unit.
• the unscrambled output is filtered by a de-emphasis fil ⁇ ter (208) before going through an expander (209).
• the ex ⁇ panded signal is bandpass filtered (210) and amplified (211).
• the amplifier (211) is controlled by the microprocessor (212). By operating a control on the remote unit, the user can in ⁇ crease or decrease the speaker (220) volume by increasing or decreasing the gain applied to the signal at this point.
• the amplified signal is input to the earpiece speaker of the remote unit.
• the microphone (221) of the remote generates the audio signal that is bandpass filtered (213), compressed (214), and filtered by a pre-emphasis filter (215) before being processed by the scrambler circuit (216).
• This circuit (216) is the second half of the integrated circuit used to unscramble the received signal.
• the scrambled signal is bandpass filtered (217) before being modulated to a frequency in the range of 49.67 - 49.99 MHz by the transmitter (218).
• the modulated signal is band ⁇ pass filtered (219) to remove the signal outside this frequency range and is transmitted on the remote's antenna (201).
• the keypad on the remote (222) is used to take the tele ⁇ phone off hook, enter telephone numbers, change the fre ⁇ quency used to communicate with the base, and to enable the scramble demonstration function.
• the keypad enables the scrambling demonstration function by telling the micropro ⁇ cessor to generate a control signal to the scrambling inte ⁇ grated circuit.
• the base unit also has a keypad.
• control signals in both the remote and the base units are connected to the transmitter after the scrambling function so that these signals are not scrambled.
• the control signals, generated by the microprocessor, are wire-ORed with the scrambled voice signal to the transmitter input.
• the scrambling of the signal between the remote and the base is operating continuously. This scrambling, how ⁇ ever, is not evident to the telephone user or the party on the other end of the call. It would not be known, therefore, if the scrambling was operating properly.
• the scrambling demon ⁇ stration process of the present invention provides both parties to the telephone call the ability to hear the scrambled version of the signal.
• the scrambling demonstration process is illustrated in FIG. 3. While the telephone is in a call, the keypad is scanned (301) by the microprocessor for the depression of a key, such as a Secure Demo key, that indicates that the remote unit user wishes to enter the scrambling demonstration mode. In the preferred embodiment, this mode is referred to as the Secure Demo mode.
• a key such as a Secure Demo key
• a timer in the microproces- sor is started (303). If the key is released immediately (304), the timer is cleared (305) and the keypad scanned again (301). If the key is still depressed (304), the timer is incremented (306) and checked to determine if the key has been depressed for at least 3 seconds (307). This time check is continued until the key has been depressed for 3 seconds. At this point, the scrambling demonstration mode is operating (308). This can be indicated on the remote or the base by flashing indicator lights (309). The remote keypad may be used for the above pro ⁇ cess or, if the base has a keypad, this keypad may be used to enter the scrambling demonstration mode. 5 The block diagram of the MX108DW Full-Duplex
• Voiceband Scrambler integrated circuit is illustrated in FIG. 4. Since this integrated circuit uses frequency inversion scrambling, a signal that is input to the circuit that has al ⁇ ready been scrambled will be returned to normal by the ⁇ r-
• the MX108DW In order to put the telephone into the scrambling demonstration mode, the MX108DW must be able to transmit the input signal without scrambling. This is accomplished by the control input labeled Qear/Scramble. By applying a logic one
• the microprocessor begins with the microprocessor in a stop or sleep mode (501).
• the microprocessor then receives an in ⁇ terrupt (502) by an external clock. This interrupt is done peri ⁇ odically to enable the microprocessor to check for inputs from the base unit or the keypad on the remote unit.
• the microprocessor then checks the battery saver switch to determine the mode of the telephone (503). If the switch is in the normal operation mode, power is applied to the receiver and the received signals are monitored for data from the base unit (504). If the battery saver switch is in the
• ⁇ 35 power conservation mode position power is not applied to the receiver.
• the keypad is scanned to determine if a key has been depressed (505). If a key was depressed (506), the key is pro ⁇ Completed (507). An example of such a key is a last number redial key or number key for dialing a telephone number. If a key was not depressed (506), it is determined if power was applied to the receiver (508). If the receiver is on, it is determined if data was received (509). If data was received, the data is processed (510).
• An example of the type of data re ⁇ ceived is a ring signal from the base unit instructing the re- mote unit to activate the alert tone.
• a software timer is next checked to determine if the mi ⁇ croprocessor has been active for the required time (511).
• the microprocessor is awake for 40 ms in the power conservation mode and 125 ms in the normal mode. The shortened time for the power conservation mode reduces the power load on the remote's battery.
• the process repeats from scanning the keypad (505). If the time has elapsed (511), the power to the receiver is removed (512), if it had been ap- plied initially.
• the battery saver circuit of the present invention is il ⁇ lustrated in FIG. 6. This circuit is comprised of a switch (601) to the microprocessor (602) input. When the switch (601) is closed, a logic one is input to the microprocessor (602), thus indicating the telephone is in the power conservation mode. The interrupt to bring the microprocessor (602) out of the sleep mode comes from either the keypad (603) or the sleep timer (604).
• a transistor switch (605) is coupled to the microproces ⁇ sor to allow tiie microprocessor (602) to turn the transistor (605) on and apply power to the receiver.
• the recovered data received from the base unit is input from the receiver to the microprocessor.
• the cordless telephone while in the power conservation mode, can still make or receive calls by pressing a key on the keypad or, in the preferred embodiment, opening the flip of the remote unit.
• the remote automati ⁇ cally returns to the power conservation mode, if that was the mode selected before the call.
• the user can use the remote to enter telephone numbers to be stored in the base unit's memory for memory dialling later. These numbers can be entered while the remote is in the power conservation mode.
• the microprocessor automatically turns on the transmitter and sends the numbers to the base unit for storage. After a certain time, the transmitter turns off and the remote automatically reverts to the power conservation mode if that was the mode previously selected.
• a wireless or cordless telephone having controllable scrambling between the remote unit and the base unit has been shown, thus providing secure conversations be ⁇ tween the telephone user and the land-line party.
• the tele ⁇ phone also has a mode for normal power consumption and a power conservation mode. By placing the telephone in the power conservation mode, the telephone can be used for longer periods between battery charging.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Human Computer Interaction (AREA)
• Computer Networks & Wireless Communication (AREA)
• Signal Processing (AREA)
• Business, Economics & Management (AREA)
• Emergency Management (AREA)
• Mobile Radio Communication Systems (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=25059469

Family Applications (1)

Country Status (7)

Cited By (21)

Families Citing this family (1)

Citations (2)

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• 1992
  • 1992-07-14 TW TW081105542A patent/TW198141B/zh active
  • 1992-07-24 AU AU24178/92A patent/AU2417892A/en not_active Abandoned
  • 1992-07-24 WO PCT/US1992/006143 patent/WO1993006682A1/en unknown
  • 1992-09-09 IT ITRM920656A patent/IT1258482B/it active IP Right Grant
  • 1992-09-14 MX MX9205231A patent/MX9205231A/es unknown
  • 1992-09-14 CN CN92110607A patent/CN1071292A/zh active Pending
  • 1992-09-16 FR FR9211037A patent/FR2683408A1/fr active Pending

Patent Citations (2)

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