Patent Application
20090191922
The invention relates generally to operation of portable hands-free phone accessories, and more particularly to reducing power consumption of such devices when the mobile communication device being supported is moved away from the device such that hands-free operation is no longer needed, and further to turning on the portable hands-free phone accessory when in a low power mode and a supported mobile communication device comes within sufficient range of the portable hands-free phone accessory.
A portable hands-free phone accessory is a device which allows “hands-free” operation of a phone device such as a mobile communication device. The portable hands-free phone accessory links with the phone device to replicate audio signals such that the user doesn't need to hold the phone device to their head. Hands-free operation therefore allows people to communicate while performing other activities with more ease. A common use for a hands-free phone accessory is as an in-vehicle speakerphone. Some vehicles are manufactured with integrated hands-free systems, but there is still a substantial number of new vehicles and older vehicles which have no such integrated system. As a result, there are a number of portable hands-free phone accessories for use in vehicles, and elsewhere.
Being portable, a portable hands-free phone accessory is typically battery powered. A common problem with these devices is that the user forgets to turn them off when, for example, leaving a vehicle in which the device is located, which unnecessarily depletes the charge of the hands-free device's battery. A further problem with the use of portable hands-free phone accessory devices is that the user may move away from the accessory device while a link is still maintained between the phone and the accessory device. When a call comes in to the phone, the phone will ring normally, but if the user answers the call at the phone, the audio is still being routed to the accessory device, so the user may not hear the person calling, or the person calling may not be able to hear the user, or both. Therefore there is a need for a means by which the portable hands-free accessory device can detect that it is no longer needed, and then shut itself down to a low power operating mode.
Likewise, when a person gets into their vehicle, it would be beneficial if the portable hands-free phone accessory could turn itself on, and provide hands-free operation, if so desired by the user. Accordingly, there is a corresponding need by which the portable hands-free phone accessory can determine that it will be needed, and power up from a low power mode to an operating mode.
The present invention discloses a method for operating a portable hands-free phone accessory in powering down when no longer needed, and power up automatically when hands-free operation of a supported mobile communication device may be needed. One embodiment of the invention commences while the portable hands-free phone accessory is not connected to a phone and is operating in a low power mode by detecting at least one of a vibration of the portable hands-free phone accessory or a radio signal indicating the presence of a mobile communication device. The vibration may correspond to that caused by a vehicle door closing. Upon detecting the vibration or radio signal the method then commences powering up the portable hands-free phone accessory to an initial operating mode, and connecting to a mobile communication device over a wireless personal area radio link. Subsequently the portable hands-free phone accessory begins providing hands-free phone operation for the mobile communication device.
In another embodiment of the invention there is provided a method for operating a portable hands-free phone accessory commenced upon providing hand-free operation for an mobile communication device to which the portable hands-free phone accessory is wirelessly connected via a personal area network link. While in the hands-free mode, the portable hands-free phone accessory detects the occurrence of a condition indicating the mobile communication device has moved away from the portable hands-free phone accessory, and outside of a range corresponding to a vehicle cabin range. In response, the method then commences by powering the portable hands-free phone accessory down from an operating power level to a low power level, wherein the portable hands-free phone accessory cannot provide hands-free operation while in the low power mode.
There are shown in the drawings, embodiments which are presently preferred, it being understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown.
While the specification concludes with claims defining features of the invention that are regarded as novel, it is believed that the invention will be better understood from a consideration of the description in conjunction with the drawings. As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. Further, the terms and phrases used herein are not intended to be limiting but rather to provide an understandable description of the invention.
Referring now to
The portable hands-free phone accessory comprises a controller 106 which is programmed with instruction code stored in a memory 108. The controller may be any suitable microprocessor or microcontroller, or other suitable logic processor. The memory may be any combination of read only memory, random access memory, reprogrammable memory and so on. The controller carries out instructions which are designed to operate the portable hands-free phone accessory in accordance with the teachings herein, as well as additional functions which may be beyond the scope of the invention. The portable hands-free phone accessory includes an audio processor 110 which processes audio signals received from the phone device, and acoustic signals received at the portable hands-free phone accessory. The signals received from the phone device will typically be digitized signals which need to be converted to analog signals by the audio processor 110 and played over a speaker 114 or other audio transducer. Similarly, the portable hands-free phone accessory has a microphone 116 for receiving acoustic signals such as, for example, the voice of the user when speaking, and coverts the resulting electrical analog signal to a digitized signal which may be routed to the phone device. To send and receive signals with the phone device, the portable hands-free phone accessory includes an interconnection means, such as a personal area network (PAN) network interface controller (NIC) 112. The NIC 112 controls access to the transmission medium and controls operation of the transceiver according to established interface protocol.
In order to power from a low power or sleep mode to an operating mode, and vice-versa, the portable hands-free phone accessory must be able to determine the absence or presence of the phone device, or infer its absence or presence and prompt for confirmation. Since the portable hands-free phone accessory is typically used as a speakerphone in a vehicle, the invention uses the vibration of a car door shutting to trigger the change in mode. Accordingly, the portable hands-free phone accessory may comprise an acceleration or vibration detection means 118. A common vibration sensing means is an array of micro-electromechanical switches or systems (MEMS). A MEMS array allows the characterization of vibrations experienced by the device in which they are mounted. Using three MEMS sensors aligned in each of three axes allows three dimensional vibration characterization. The vibration experienced by the portable hands-free phone accessory inside a vehicle caused by closing a vehicle door can be generally characterized, and stored as a vibration profile in the memory 108. Upon detecting a vibration or acceleration, the controller can store measurements and compare them in magnitude and time with the vibration profile corresponding to the closing of a vehicle door. It may be assumed that the closing of the vehicle door occurs in conjunction with a person entering or exiting the vehicle. The portable hands-free phone accessory may request confirmation of such since the vibration detection may arise from other similar vibrations, such as a passenger door closing. For example, a synthesized voice prompt may be generated from speech information 120 stored in the portable hands-free phone accessory. The prompt may ask the user to take an action or otherwise respond in a way that is detectable by the portable hands-free phone accessory. A lack of response indicates the user, and therefore a phone device, are not nearby.
Without the benefit of an accelerometer, the portable hands-free phone accessory may use the microphone 116 to detect the sound of a vehicle door closing. As with vibration, the acoustic signature of a vehicle door closing may be generally characterized and compared against sounds received at the portable hands-free phone accessory when the portable hands-free phone accessory is not engaged in a call.
An alternative method of detecting movement of the phone device away from the portable hands-free phone accessory is through the use of positioning information, as obtained, for example, by a satellite positioning receiver (SPR) 122. An SPR informs the portable hands-free phone accessory of its present location, as determined by receiving positioning signals transmitted by positioning satellites. The portable hands-free phone accessory may periodically receive location information from the phone device, assuming it is likewise equipped to determine its present location. The portable hands-free phone accessory may compare its location with the location of the phone device, and determine that the phone device has moved into or out of a range corresponding to a vehicle cabin range.
The phone device 104 may be a mobile communication device, such as a cellular telephone or similar device. It will typically include a controller 124 operating in conjunction with instruction code stored in a memory 126, and may include a wide area network modem 128 for communicating with wide area wireless networks, such as cellular networks. The mobile communication device also includes a PAN network interface controller 130 for communicating with nearby devices wirelessly, including the portable hands-free phone accessory. The mobile communication device also includes an audio processor 132 for playing audio signals over a speaker 134, and for converting acoustic signals received at a microphone 136 to electrical signals which are typically digitized.
In operation, the portable hands-free phone accessory is first paired with the mobile communication device over the PAN link. Pairing involves the portable hands-free phone accessory storing an identifier of the mobile communication device's PAN network interface controller in memory, and upon power up to an operating mode, searching PAN signals for that identifier, while ignoring signals from other devices. Once both the mobile communication device and portable hands-free phone accessory are powered up and linked, the portable hands-free phone accessory can provide hands-free operation for the mobile communication device. Upon commencement of a call, the call audio is processed by the portable hands-free phone accessory, rather than the audio processor 132 of the mobile communication device, generally.
Referring now to
In detecting the presence of the mobile communication device (204) there are several conditions which may be periodically monitored by the portable hands-free phone accessory (214). For example, the vibration or sound created by closing a vehicle door may be used to infer the mobile communication device has come in range of the portable hands-free phone accessory. In another embodiment, the portable hands-free phone accessory periodically monitors the PAN medium for a probe signal from the mobile communication device. Upon detecting the signal, and the identifier used by the mobile communication device, the portable hands-free phone accessory determines the strength of the signal being received. The portable hands-free phone accessory may compare the received signal strength to a threshold, or check its own transmit power level needed to maintain a PAN link as evidence that the mobile communication device is nearby.
Referring now to
In detecting a condition indicating the mobile communication device has moved away from the portable hands-free phone accessory (304), as mentioned, there are a variety of conditions which may be monitored. The portable hands-free phone accessory may monitor any one of them or a combination of them. For example, a vibration or sound corresponding to that cause by a vehicle door closing may be detected. The portable hands-free phone accessory may also monitor signal strength, directly or indirectly, of the wireless link between the portable hands-free phone accessory and the mobile communication device. The portable hands-free phone accessory may monitor received signal strength, or it may monitor the transmit power level used by the portable hands-free phone accessory's PAN controller. If the PAN transmitter has or is increasing transmit power, it may be due to the mobile communication device moving away from the portable hands-free phone accessory. To reduce a false detection due to a momentary change in signal strength, the portable hands-free phone accessory may keep a running average of signal strength or transmit power by periodically sampling and maintaining a buffer of the most recent samples, and averaging their values together. The running average may then be compared to a threshold which has been determined to indicate that the mobile communication device has been moved away from the portable hands-free phone accessory. In addition to signal strength, the portable hands-free phone accessory may also monitor the occurrence of the PAN link dropping and reconnecting, as may occur when the mobile communication device is moving in and out of range of the portable hands-free phone accessory, but is still close enough that average signal strength doesn't drop below a preselected threshold. It is also contemplated that the portable hands-free phone accessory may receive location information from the mobile communication device, assuming the mobile communication device is equipped to determine its location. The location of the mobile communication device, as reported to the portable hands-free phone accessory by the mobile communication device, may be compared to its own location, if the portable hands-free phone accessory has a location determination means, or it may be compared to information generated by the accelerometer. If the location reading of the respective devices differ, or if the location of the mobile communication device is changing and the accelerometer in the portable hands-free phone accessory indicates it is not moving, then a determination that the mobile communication device has moved away from the portable hands-free phone accessory may be made, and the user prompted to confirm or reverse that determination.
This invention can be embodied in other forms without departing from the spirit or essential attributes thereof. Accordingly, reference should be made to the following claims, rather than to the foregoing specification, as indicating the scope of the invention.
