Abstract:
A low-power wireless communication device is in a sleep or standby mode of operation for extended periods of time, periodically becoming fully operational and issuing a “check in” message to a base station, thereby inhibiting the ability of the base station to assist in the locating of device, and remotely updating the settings or operational programming of the device much of the time. Upon receipt of a command to locate a misplaced low-power wireless device or to update the device, a base station queues an associated command in a task queue. Upon receipt of a check-in message from an associated low-power wireless device, indicating it is in a fully powered and communicative state of operation, the base station searches its task queue for applicable commands relative to the specific wireless device and executes them via communication with the now fully-operational wireless device.

Description:
FIELD OF THE INVENTION 
     This invention relates in general to wireless electronic communication devices and, in particular, to an apparatus and a method capable of both locating and updating the settings and/or programming of certain low-power wireless communication devices that are primarily in an uncommunicative mode of operation in order to preserve their battery life. 
     BACKGROUND OF THE INVENTION 
     Wireless technology is currently becoming increasingly popular, including being integrated into many types of devices that need to convey information only intermittently, and that have been previously networked, if at all, via hardwired communication channels. For example, wireless technology has now been integrated into many home monitoring systems, including transducers that indicate the security of doors and windows, home security video cameras which may transmit data primarily upon the detection of motion in their field of view, and weather monitoring equipment. Wireless technology is, of course, also increasingly popular in portable communication devices, such as cellular telephones and smartphones. 
     Another popular application of wireless communication technology is the Personal Emergency Response System (PERS) market, which has been estimated to have approximately one billion dollars in annual North American sales. A typical PERS system in a residence includes a base station that facilitates voice communication between one or multiple portable, wireless transceivers, on the one hand, and automatically called parties, on the other hand, such as a family member, an emergency services operator, or a private monitoring service. Such communication is typically initiated by a user, who wears a portable communications transceiver in the form of a PERS pendant, and who operates the device by pressing a “call” or “panic button of the transceiver in the event of an emergency. 
     As remote and portable wireless transceivers are typically battery operated, there is a significant desire to reduce their power consumption, in order to reduce the frequency with which the device&#39;s batteries must be recharged or replaced. One approach to reducing power consumption and extending battery life is device power management, whereby most or all of a device may be turned off, or placed in a low-power sleep or standby mode of operation, particularly for devices that require only intermittent communication with a base station, with the communication being initiated by the mobile device on either on a periodic or an on-demand basis, such as, for example, a PERS pendent or other mobile device, which may autonomously transition from a low-power sleep or standby mode to a transmit-only operational mode, wherein the radio transmitter portion of its transceiver is temporarily powered while the radio receiver portion of its transceiver remains unpowered, to perform a “check in” operation by transmitting a predetermined signal or message once every predetermined time period such as, for example, once every approximately thirteen hours. 
     As a result, these low-power wireless devices are commonly out of communication with their base station for extended periods of time. This frequent inaccessibility inhibits the ability of the base station to perform certain desirable functions, such as assisting in the locating of misplaced portable transceivers, and remotely updating the settings or operational programming of the portable transceivers. 
     Accordingly, it is an object of the present invention to provide an apparatus and a method for locating a misplaced low-power wireless communication device. 
     It is another object of the present invention to provide an apparatus and a method for remotely updating the settings of a low-power wireless communication device. 
     It is yet another object of the present invention to provide an apparatus and a method for remotely updating the operational programming of a low-power wireless communication device. 
     These and other objects, features and advantages of the invention will be apparent from the following detailed disclosure, taken in conjunction with the accompanying sheets of drawings, wherein like reference numerals refer to like parts. 
     SUMMARY OF THE INVENTION 
     The present invention comprises a method of locating a misplaced low-power wireless communication device that is primarily in an uncommunicative mode of operation. First, a command is received by a base unit, indicating that a misplaced low-power wireless communication device is to be found. The base unit adds a “locate mobile device” command to a task queue that the base unit maintains in its memory. Next, the base unit listens for mobile messages from the low-power wireless communication device. Upon receipt of a mobile message, the base unit determines if it is a periodic check-in message from the misplaced low-power wireless communication device. If so, the base unit searches its task queue for a locate mobile device command, and then issues a find command message to the low-power wireless communication device, prompting the misplaced low-power wireless communication device to take action assisting in its location, such as, for example, the issuance by low-power wireless communication device of an audible alert, such as a periodic beeping or chirping sound. In an embodiment of the present invention, the low-power wireless communication device comprises a mobile unit of a Personal Emergency Response System, and the above described steps are performed by a base unit of a Personal Emergency Response System. Moreover, in an embodiment of the invention, the low-power wireless communication device, when issuing its periodic check-in message, also powers its radio receiver for either a predetermined amount of time, or until a responsive communication is received from a base unit. 
     The present invention also comprises a method of updating a low-power wireless communication device that is primarily in an uncommunicative mode of operation. First, a command is received by a base unit, indicating that the base unit is to perform at least one of modifying a setting and modifying programming of the low-power wireless communication device. The base unit adds a “modify setting” command and/or a “modify programming” command to a task queue that the base unit maintains in its memory. Next, the base unit listens for mobile messages from the low-power wireless communication device. Upon receipt of a mobile message, the base unit determines if it is a periodic check-in message from a low-power wireless communication device that is to be updated. If so, the base unit searches its task queue for a “modify setting” command and/or a “modify programming” command. If a “modify setting” command is found in the task queue, the base unit issues a “modify setting” message to the low-power wireless communication device, which has temporarily powered its radio receiver upon the issuance of a “check in” message, prompting the low-power wireless communication device to update at least one parameter or setting with data contained within the modify setting command. If a “modify programming” command is found in the task queue, the base unit issues at least one message to the low-power wireless communication device containing replacement or additional programming instructions, prompting the low-power wireless communication device to load and begin execution of the replacement or additional programming instructions. As in the prior embodiment of the present invention, the low-power wireless communication device comprises a mobile unit of a Personal Emergency Response System, and the above described steps are performed by a base unit of a Personal Emergency Response System. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is schematic diagram of a communication system including a base station and a low-power wireless communication device; 
         FIG. 2  is a flowchart of a portion of the operation of the base station; and 
         FIG. 3  is a flowchart of a portion of the operation of the low-power wireless communication device. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail several specific embodiments, with the understanding that the present disclosure is to be considered merely an exemplification of the principles of the invention and is not intended to limit the invention to the embodiments disclosed 
     A mobile-base communication system  10  in accordance with the present invention is shown in  FIG. 1  as comprising base unit  20  and mobile unit  100 , communicating with each other via radio waves  80 . The bidirectional communication protocol between base unit  20  and mobile unit  100  may comprise the Digital Enhanced Cordless Telecommunications (“DECT”) standard, commonly used in digital cordless telephone handsets, or other suitable wireless communications protocols, such as wireless network-based communications protocols (e.g., Bluetooth and the IEEE 802.11 family of protocols). Although only a single mobile unit  100  is shown in  FIG. 1 , base unit is preferably capable of communicating with a plurality of mobile units  100 , each of which is assigned a unique identifier for use within the DECT communication protocol. 
     Base unit  20 , which may be, for example, a PERS system base unit, comprises microcontroller  30 , radio transceiver  40 , antenna  45 , network interface  50 , switches  60 , and display LEDs  70 . Microcontroller  30  includes an internal microprocessor, program and data memory units, analog and digital input/output ports, timers, and power management circuitry and may comprise, for example, a PIC microcontroller manufactured by Microchip Technology Inc. Radio transceiver  40  is coupled to microcontroller  30  via a digital data interface and may comprise a special purpose integrated circuit implementing a specific communication protocol, such as the DECT standard, and having power management capability and may comprise, for example, an LMX3161 radio transceiver manufactured by Texas Instruments, Inc. Network interface  60  enables microcontroller  50  to communicate externally via, for example, a conventional analog telephone network, and may comprise, for example, a TP3420A integrated circuit manufactured by Texas Instruments, Inc. 
     The anodes of display LEDs  70  are coupled to output pins of a data port of microcontroller  30  via current limiting resistors  71 . The cathodes of display LEDs  70  are coupled to ground  63 . Accordingly, microcontroller  30 , by controlling the individual logic level of its associated digital data port output pins, may programmatically turn display LEDs on and off to indicate, for example, whether or not base unit  20  is currently in setup mode, or whether or not base unit  20  is currently scanning for mobile units  100  to communicate with. Switches  60  are for user input purposes and may comprise, for example, momentary pushbutton single pole, single throw (“SPST”) switches. One contact of each switch is coupled to a digital port input pin of microcontroller  30 , with intermediate pull-up resistors  61  being coupled to supply voltage  62 . The other contact of each switch  60  is coupled to ground  63 . By periodically poling the value of a data input port associated with switches  60 , microcontroller  30  may determine whether each individual switch  60  is presently in a closed (logic zero at the input port) or open (logic one at the input port) configuration. Specific functions may be assigned to each switch  60 . For example, a user depressing a specific switch  60  may command or initiate a “find” operation to be performed, towards locating a lost or misplaced mobile unit  100 , or to command or initiate a system self-test operation. 
     Mobile unit  100 , which may be, for example, a PERS system mobile pendant, comprises microcontroller  110 , radio transceiver  120 , antenna  125 , power management timer  130 , battery  140 , speaker  111 , microphone  112 , display LEDs  150  and switches  160 . Microcontroller  110  includes an internal microprocessor, program and data memory units, analog and digital input/output ports, timers, and power management circuitry and may comprise, for example, a PIC microcontroller manufactured by Microchip Technology Inc. Radio transceiver  120  is coupled to microcontroller  110  via a digital data interface and may comprise a special purpose integrated circuit implementing a specific communication protocol, such as the DECT standard, and having power management capability and may comprise, for example, an LMX3161 radio transceiver manufactured by Texas Instruments, Inc., or, alternatively, another transceiver having separate power management capability for both the transmitter and receiver portions of the transceiver Power management timer  130  is employed to manage the power state of microcontroller  110 , enabling microcontroller  110  to commonly remain in a low-power, sleep mode, until a timer trigger initiated by power management timer  130  causes microcontroller  110  to transition to full operational mode. Microcontroller  110 , in turn, governs the power state of transceiver  120 , leaving it unpowered much of the time, including whenever microcontroller  110  is in low-power, sleep mode of operation. This, in turn, further conserves the power stored within battery  140 . Power management timer  130  may, alternatively, be an internal timer contained within the power management circuitry of microcontroller  110 . 
     The anodes of display LEDs  150  are coupled to the output pins of a digital data port microcontroller  110  via current limiting resistors  151 . The cathodes of display LEDs  150  are coupled to ground  142 . Accordingly, microcontroller  110 , by controlling its associated digital data port output pins, may programmatically turn display LEDs on and off to indicate, for example, whether or not mobile unit  100  is currently in setup mode, or whether or not mobile unit  100  is currently scanning to establish communication with base unit  20 . Switches  160  are for user input purposes and may comprise, for example, momentary pushbutton SPST switches. One contact of each switch is coupled to a digital data port input pin of microcontroller  110 , with intermediate pull-up resistors  161  being coupled to supply voltage  141 . The other contact of each switch is coupled to ground  142 . By periodically poling the value of a data input port associated with switches  160 , microcontroller  110  may determine whether each switch  110  is presently in a closed (logic zero at the input port pin) or open (logic one at the input port pin) configuration. Specific functions may be assigned to each switch  160 . For example, a user depressing a specific switch  160  may initiate an emergency communication operation, establishing 2-way communication by causing base unit  20  to dial and establish a telephone connection with emergency personnel or a family member its telephone network interface  50 , enabling the user to converse with the called party via speaker  111  and microphone  122 . Moreover, switches  160  are preferably also coupled to power management timer  130  to cause an immediate transition of microcontroller  110  to full powered mode (if necessary) upon the user activation of any switch. 
     In a preferred embodiment, to conserve the charge of battery  140 , power management timer  130  is configured to “wake” microcontroller  110  only infrequently, such as approximately once every thirteen hours. Each time microcontroller  110  transitions to fully powered mode as commanded by power management timer  130 , it powers both the transmitter and receiver portions of its transceiver  120 , which is likewise generally kept unpowered to conserve battery charge, and issues a “check in” communication message to base unit  20  via transceiver  120  and antenna  125  using radio waves  80 . The check in communication from a given mobile unit  100  permits the mobile unit to provide base unit  20  with an indication of its battery charge and overall status, and, in turn, to potentially receive a response message from base unit  20  indicating the base unit&#39;s status. This permits both base unit  20  and each mobile unit  100  to provide a visual or audible indication of any system errors or warning conditions that may be encountered. The receiver portion of transceiver  120  is then used to listen for a message, either responsive to the check-in message or otherwise, from base unit  20 . If the message from base unit  20  is a shutdown command, or a system health message indicating that the overall system is fully operational, microcontroller  110  will then cause both the transmitter and receiver portions of transceiver  120  to again be unpowered, and microcontroller  110  will then reenter its low-power, sleep mode, until the next periodic awakening prompted by power management timer  130 . 
     In addition to an indication of overall system health, the message from base unit  20  may also include a command or indication that mobile unit  100  is to perform a specific operation. Specifically, and as detailed further below, a message from base unit  20  to mobile unit  100  may initiate a “find” operation, indicating that the mobile unit has been misplaced, commanding the mobile unit to take action, such as emitting periodic beeps or other sounds, to assist in its being located by the user. Moreover, a message from the base unit may be used to initiate a data transfer from the base unit to the mobile unit. The data transfer may consist of new setting information, such as, for example, remotely commanding the volume setting of the mobile unit, or the frequency with which the mobile unit transitions from sleep to active modes of operation. Alternatively, the data transfer may be a programming upgrade, which microcontroller  110  is to transfer to its internal program memory and then begin executing. 
     Referring to  FIG. 2 , a portion  200  of the operation of the programming of microcontroller  30  of base unit  20  is shown. In step  201 , device initialization of base unit  20  is performed, such as when power is initially applied to base unit  20 . Next, in step  202 , microcontroller  30  polls the position of each switch  60 . In step  203 , a search is made to determine if the user has depressed a switch indicating that a base unit has been misplaced, and a “find” operation is to be performed. If so, transition is taken to step  204 , where a search is made of a pending task queue maintained within the memory of microcontroller  30  to determine whether a find operation is already pending in the queue. If so, transition is taken to step  206 . If not, a find operation is added to the task queue, and transition is taken to step  206 . 
     The task queue of microcontroller  30 , in general, is preferably a first-in, first-out (“FIFO”) queue of tasks that are to be performed in association with one or more mobile units  100  associated with base unit  20 . As detailed further below, inasmuch as each mobile unit  100  is left in a substantially unpowered, battery-conserving mode of operation most of the time, tasks to be performed in association with a particular mobile unit generally cannot be immediately performed, as each mobile unit is incommunicative, with its transceiver being unpowered, when in its normal, low-power, sleep mode of operation. Accordingly, a queue is maintained within the memory of microcontroller  30  of tasks that have been triggered or commanded, such as by user input, but that are not currently capable of being performed in view of the lack of current communication with an applicable mobile unit  100 . 
     Within step  206 , a test made to determine if base unit  20  has been commanded to perform an update of the firmware programming within one or more mobile units  100 . Such a command, and the associated data, may be received from base unit  20  from a remote computer via network interface  50  of base unit  20 . The remote computer may, for example, be associated with a manufacturer of communication system  10  and maintained for purposes of remotely updating previously purchased communication systems  10  with the latest version of software releases. If the base unit  20  has been commanded to perform a firmware update, transition is taken to step  207 , where a search is made of the pending task queue to determine whether a firmware update operation is already pending in the queue. If so, transition is taken to step  209 . If not, a firmware update operation is added to the task queue, and transition is taken to step  209 . 
     Within step  209 , a test is made to determine if base unit  20  has been commanded to change a setting or parameter within the memory of microcontroller  110  of one or more mobile units  100 . Such a command may be received by base unit  20 , for example, within a data message received via network interface  50  from a host computer. Alternatively, such a command may be from some form of user input to base unit  20 , such as a function associated with a designated pushbutton switch  60 . If such a command has been received, transition is taken to step  210 , where a search is made of the pending task queue to determine whether a remote setting change operation is already pending in the queue. If so, transition is taken to step  212 . If not, a remote setting change operation is added to the task queue, and transition is taken to step  212 . 
     In step  212 , a test is made to determine if a complete mobile message has been received from a mobile unit  100  associated with base unit  20 . If not, transition is taken to step  202 , where user activated switches  60  are again polled for activity. Otherwise, transition is taken to step  213 , where a test is made to determine if the mobile message received from a mobile unit  100  was a periodic check-in message, indicating that a mobile unit  100  has recently reawakened from its normal, low-power state and is checking in with its associated base unit  20 . If not, transition is taken to step  216 , where the mobile message, which may comprise, for example, a user-initiated emergency communication, is processed, after which transition is taken to step  202 , where user activated switches  60  are again polled for activity. 
     Otherwise, transition is taken to step  214 , where a test is made to determine if the task queue contains at least one queued task associated with the specific mobile unit  100  that issued the check-in message. If not, transition is taken to step  216 , where usual check-in message processing occurs. For example, if the check-in message includes an indication that a mobile unit  100  has little remaining battery power or is in some way malfunctioning, base unit  20  may issue an audible or visual alert to the user. 
     If, however, there is at least one task queued for the mobile unit  100  that is currently checking in, all queued tasks for that mobile unit  100  are removed from the queue, and transition is taken to step  215  where each task just removed from the queue is sequentially processed. 
     If the task (or one of the tasks) to be currently processed in step  215  is the “find” task, indicating that the associated mobile unit  100  has been misplaced, a “find” message is transmitted from base unit  20  to the mobile unit  100 . Receipt of the find message by the mobile unit  100  causes the mobile unit to remove power from its transceiver to conserve battery power, and to begin emitting a periodic sound, such as a beeping sound every several seconds, to assist the user in locating the misplaced mobile unit  100 . Once the user has located the mobile unit  100 , he or she may stop the beeping and terminate the find operation by pressing any user input button  160  (such as an emergency call button or a system test button) on the mobile unit  100 . This, in turn, causes the mobile unit  100  to return to its fully unpowered, sleep mode. 
     If the task (or one of the tasks) to be currently processed in step  215  is the mobile firmware update task, indicating that the programming of the associated mobile unit  100  is to be updated, a “firmware update” message is transmitted from base unit  20  to the mobile unit  100 . This begins what may be a relatively lengthy sequence of data packets containing the new firmware to be transmitted from base unit  20  to mobile unit  100 , with each packet being checked for transmission errors by mobile unit  100 , which then issues responsive acknowledgement messages (prompting transmission of the next packet in sequence by base unit  20 ) or negative-acknowledgement messages (in the case of a transmission error being detected by mobile unit  100 , prompting retransmission of the current data packet by base unit  20 ). Upon the receipt of a complete set of firmware update messages, microcontroller  110  of mobile unit  100  will initiate a system reboot. Upon rebooting, microcontroller  110  will automatically replace its prior execution firmware with the new firmware just received from base unit  20 . Mobile unit  100  will then continue its normal operation in accordance with its updated programming. 
     If a task (or one of the tasks) to be currently processed in step  215  is the remote setting change task, indicating that one or more settings or parameters of the associated mobile unit  100  is to be replaced with a new value or values, an “update setting” message is transmitted from base unit  20  to the mobile unit  100 . This message includes an identifier or identifiers of the setting(s) or parameter(s) to be updated, together with the new associated value(s). Upon receipt of the update setting message, mobile unit  100  will replace its existing setting(s) or parameter(s) identified in the message with the new values also contained in the message. This permits, for example, optional functional features of mobile unit  100  to be selectively and remotely activated or deactivated, or settings of mobile unit  100 , such as speaker volume, to be remotely modified. Transition is then taken to step  216 , where usual check-in message processing occurs. 
     Referring to  FIG. 3 , a portion  300  of the operation of microcontroller  110  of mobile unit  100  is shown. In step  301 , device initialization of mobile unit  100  is performed, such as when power is initially applied to mobile unit  100 . Next, in step  302 , microcontroller  302  enters a sleep or lower power mode or, if already in such a mode, remains there. In step  303 , a test is made for a user input, such as, in the case where mobile unit  100  is a PERS pendant, pressing a call” or “panic button associated with one of switches  160 . This test may be made by polling a data input port, if microcontroller  110  has such capability while in low-power mode. Alternatively, the outputs of switches  160  may be coupled to dedicated interrupt input pins of microcontroller  110  that are configured to cause microcontroller  110  to exit low-power mode upon an external interrupt trigger condition. 
     In either case, if a user input has occurred, microcontroller  110  exits low-power or sleep mode, and transition is taken to  304 , where the user input is processed. Depending upon the particular user input being processed, microcontroller may remain in full power mode for some period of time, such as when a two-way telephone conversation is initiated by the user. Otherwise, if no user input has occurred, transition is taken to step  305 , where a test is made to determine whether power management timer  130  has elapsed. If not, transition is taken back to step  302 , where mobile unit  100  remains in low-power mode. Otherwise, transition is taken to step  306 , where microcontroller  110  exits lower power mode, and both the transmitter and receiver of transceiver  120  are powered. 
     Next, in step  307 , microcontroller  110 , in conjunction with the transmitter portion of transceiver  120 , issues a “check-in”, or “I&#39;m alive” indicative message, to base unit  20 . Next, in step  308 , microcontroller determines whether a complete message has been received from base unit  20 . If so, transition is taken to step  309 , where the message is processed by microcontroller  110 . Otherwise, transition is taken to step  310 , where a test is made to determine if an inactivity timer has elapsed. The inactivity timer is a countdown timer that may be set, for example, to a duration of approximately two minutes. If the inactivity timer has elapsed, transition is taken to step  302 , where transceiver  120  is again unpowered, and microcontroller  110  enters a low-power or sleep mode of operation. Otherwise, transition is taken back to step  308 . 
     In step  309 , several different types of messages from base unit  20  may be processed. For example, if mobile unit  100  has been lost or misplaced, the message to be processed may be a “find” message, causing mobile unit  100  to remove power from its transceiver to conserve battery power, and to begin emitting a periodic sound, such as a beeping sound every several seconds, to assist the user in locating the misplaced mobile unit  100 . Alternatively, the message may be a “firmware update” message, which, when received, begins what may be a relatively lengthy sequence of data packets containing the new firmware to be transmitted from base unit  20  to mobile unit  100 . Moreover, the message may alternatively be an “update setting” message, causing mobile unit  100  to replace existing setting(s) or parameter(s) with new values contained in the message. The updated setting may be, for example, a change in the predetermined interval in which mobile unit  100  is to periodically exit sleep or low-power mode and issue a “check in” message. Furthermore, if base unit  20  has no tasks queued for mobile unit  100 , the message to be processed may be a “sleep immediately” command, wherein, rather than wait for the expiration of the inactivity countdown timer, base unit  20  will immediately transition to step  302 , turn off its transceiver, and enter sleep or low-power mode. 
     It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention, and that this application is limited only by the scope of the appended claims.