Abstract:
A Bluetooth device searches for another Bluetooth device or a Bluetooth command in response to a user intervention event. A user intervention event can take many forms, such as, for example, a connection to a power source or communication device, a mechanical configuration change, or a user input. Specifically, a Bluetooth device begins searching when the user intervention event takes place. To list some examples, the Bluetooth device may enter a page state, a page scan state, an inquiry state or an inquiry scan state in response to the user intervention. Alternatively, as more examples, if the Bluetooth device is in a sniff mode, a hold mode or a park state, the Bluetooth device may enter the active mode in response to the user intervention event.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates generally to wireless communication and more particularly to Bluetooth wireless communication. 
     2. Background 
     Consumers are increasingly demanding long battery life and more consistent connections for wireless communication devices, including short range wireless communication devices. The Bluetooth wireless communication standard, as defined in the IEEE Std 802.15, defines a short range wireless communication system (also known as a wireless personal area network (WPAN)) for use on consumer electronic devices. See IEEE Std 802.15, The Institute of Electrical and Electronics Engineers, Inc., New York, N.Y., 1999 (Reaff 2003). 
     There are many Bluetooth applications. One example is a cellular telephone having Bluetooth connections to a wireless (Bluetooth) headset. That is, a cellular telephone, in addition to having a cellular transceiver (e.g., U.S. personal communication system (PCS) transceiver or a global system for mobile communication (GSM) transceiver), would have a Bluetooth transceiver for communicating with a headset. The headset also has a Bluetooth transceiver. The headset additionally has a speaker and a microphone for transmitting audio information (typically voice) to and from the user. With such a Bluetooth cellular telephone and headset, the user does not have to use a loudspeaker or hold the cellular telephone close to the user&#39;s ear and mouth to talk and listen. Essentially, this is a convenient way of carrying on a “hands free” conversation. 
     One problem with such an arrangement is that the cellular telephone and headset consume power while searching in Bluetooth, as will be described more fully below. This is especially problematic in portable applications with limited portable power supplies, such as, for example, as described above, in cellular telephones and wireless headsets. 
     Another example of a Bluetooth application is a Bluetooth connection between a Bluetooth enabled cellular telephone and a Bluetooth enabled automobile. For example, a cellular telephone might download map data, such as, for example, a map, over the cellular communication network for use with the automobile navigation system. The map data may be transferred from the cellular telephone to the automobile via a Bluetooth communication. 
     Searching in Bluetooth consumes power. Searching can be defined as checking for the presence of another Bluetooth device or for a Bluetooth command from another device. For example, a Bluetooth module in any of the following states or modes is considered searching: page state, page scan state, inquiry state, inquiry scan state, sniff mode, hold mode and park state. See IEEE Std 802.15, Volume 2, Part B, Section 8, pp. 133-188. 
     Bluetooth communication systems are made up of peer to peer communications. That is, there is no base station or central network. In a Bluetooth peer to peer connection, one of the peers, known as the master Bluetooth device, or simply as the master, controls the communication. The other peer, known as the slave Bluetooth device, or simply as the slave, is controlled by the master. One master can control up to seven slaves in the present Bluetooth standard. A grouping of a master and one or more connected slaves is called a piconet. Piconets can be connected together to form a scatternet. The arrangements of piconets and scatternets will not be described further here. 
     In page state, a Bluetooth module transmits a Bluetooth signal attempting to connect to another particular Bluetooth device. A Bluetooth page includes the address of the particular device and asks that particular device to connect. For example, in page mode, a Bluetooth enabled cellular telephone might page the headset to establish a connection between the headset and the cellular telephone. The paging device typically becomes the master. 
     In page scan state, a Bluetooth module turns its receiver on and tunes its receiver to receive a Bluetooth page signal. This is also known as listening for a page. The page scanning device typically becomes the slave. 
     In inquiry state, a Bluetooth module transmits a Bluetooth signal asking any Bluetooth enabled devices that receives the signal to respond and give its address, so that a Bluetooth connection can be established. For example a Bluetooth enabled cellular telephone might inquire whether a Bluetooth enabled wireless headset is within range of the Bluetooth enabled cellular telephone. 
     In inquiry scan state a Bluetooth module turns its receiver on and tunes its receiver to receive a Bluetooth inquiry signal. This is also known as listening for an inquiry. 
     Sniff mode is a Bluetooth mode in which a slave Bluetooth device is made to turn its receiver off except at regular intervals. The slave device in sniff mode can save power and resources this way. However, at the regular intervals, the slave Bluetooth device turns its receiver on and listens for a signal from the master Bluetooth device. Commonly, when in sniff mode, a slave device may turn its receiver on repeatedly without returning to active communication with the master Bluetooth device. 
     Hold mode is a Bluetooth mode in which a slave Bluetooth device is made to turn its receiver off for a predetermined time period. The slave device in hold mode can save power and resources this way, similar to sniff mode. However, at the end of the predetermined time period, the slave Bluetooth device turns its receiver and transmitter on and returns to the active mode. 
     In park state, a Bluetooth module of a slave Bluetooth device is made to turn its receiver off except at regular intervals. The master Bluetooth device sends a beacon signal to the slave in the park state, to help the slave maintain the connection with the master Bluetooth device. Also, if the master Bluetooth device wants the slave Bluetooth device to return to the active mode, the master Bluetooth device will send an indicator signal as part of the beacon signal to the slave Bluetooth device telling the slave Bluetooth device to return to the active mode. 
     The park state is similar to sniff mode in the sense that a device in either park state or sniff mode keeps its receiver off except at regular intervals. There are other differences and similarities which will not be described here more fully. However, at the regular intervals, the slave Bluetooth device turns its receiver on and listens to the beacon signal from the master Bluetooth device. Commonly, when in the park state, a slave device may turn its receiver on repeatedly and listen to the beacon signal without returning to an active connection with the master Bluetooth device. 
     Accordingly, searching consumes considerable power or Bluetooth network resources or both. Further, Bluetooth page signals, inquiry signals and beacon signals can cause interference with other signals, including other Bluetooth signals and other communication system signals, such as, for example, wireless local area network (WLAN) signals, such as signals conforming to the IEEE Std 802.11b or IEEE Std 802.11g, (hereinafter, collectively “802.11”). See IEEE Std 802.11b and IEEE Std 802.11g, The Institute of Electrical and Electronics Engineers, Inc., New York, N.Y., 1999 (Reaff 2003). Both Bluetooth and 802.11 signals operate at a frequency of approximately 2.4 GHz. This makes it difficult, if not impossible, for Bluetooth and 802.11 communications to occur simultaneously in the same location. 
     SUMMARY OF THE INVENTION 
     In order to overcome the problems associated with conventional Bluetooth searching, a Bluetooth device searches in response to a user intervention event. A user intervention event can take many forms, such as, for example, a connection to a power source or communication device, a mechanical configuration change, or a user input. 
     Specifically, a Bluetooth device begins searching when the user intervention event takes place. To list some examples, the Bluetooth device may enter a page state, a page scan state, an inquiry state or an inquiry scan state in response to the user intervention. Alternatively, as more examples, if the Bluetooth device is in a sniff mode, a hold mode or a park state the Bluetooth device may enter the active mode in response to the user intervention event. 
     Advantageously, the Bluetooth device may save power and network resources by keeping its transmitter or receiver or both off. Additionally, the Bluetooth device may interfere with other communications less by keeping its transmitter or receiver or both off. 
     Other aspects, advantages, and novel features of the invention will become apparent from the following Detailed Description, when considered in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Preferred embodiments of the present inventions taught herein are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings, in which: 
         FIG. 1  shows a perspective view of a Bluetooth enabled cellular telephone illustrating one user intervention event. 
         FIG. 2  shows a perspective view of a Bluetooth enabled cellular telephone illustrating several user intervention events. 
         FIG. 3  shows a block diagram of a Bluetooth enabled cellular telephone. 
         FIG. 4  shows a block diagram of a Bluetooth state machine. 
     
    
    
     DETAILED DESCRIPTION 
     A Bluetooth device searches in response to a user intervention event.  FIG. 1  shows a perspective view of a Bluetooth device undergoing a user intervention event. The Bluetooth device  102  may be a cellular telephone, as depicted in  FIG. 1 . The cellular telephone  102  is a slider type cellular telephone. Specifically, the cellular telephone has a top housing portion  104  and a bottom housing portion  106 . The top housing portion includes a display screen  108 , a speaker  110  and a menu navigation keypad  112 , including one or more navigation keys  114 ,  116 ,  118 ,  120  and  122 . The bottom housing portion  106  includes a keypad  124 , a microphone  126 , a communication connector  128  and a power supply connector  130 . 
     The top housing portion  104  is slidably connected to the bottom housing portion  106 . Specifically, the top housing portion  104  slides over the bottom housing portion  106  covering at least the keypad  124 . A user intervention event  133  is represented by arrow  133 . As shown in  FIG. 1 , the user intervention event is sliding the top portion up, relative to the bottom portion. That is, the top housing portion  104  has just been slid up revealing the keypad  124  and extending the overall length of the cellular telephone  102 . 
     Advantageously, the cellular telephone  102 , which is Bluetooth enabled, begins searching in response to the sliding up event. This is advantageous because the cellular telephone conserves power or communication resources or both by not searching until the sliding up. Specifically, a user would typically slide the top housing portion up, when the user wants to place a call. That is typically when a user would want the Bluetooth module to wake up. Waking up will be described more fully below, with respect to  FIG. 4 . 
     For example, the user may want to use a Bluetooth enabled headset with the Bluetooth enabled cellular telephone. But the user does not need the Bluetooth enabled cellular telephone and the Bluetooth enabled headset to be communicating with each other, and maintaining a connection prior to that time. Therefore, for example, the cellular telephone&#39;s Bluetooth module may enter a page state in response to the sliding up. 
     The user intervention event may be another type of mechanical configuration change. For example, the user intervention event might be a rotation of top housing portion  104  relative to bottom housing portion. For example, the cellular telephone may be a flip phone and the housing portions  104  and  106  might open like a clam shell. Other mechanical configuration user intervention events are possible as well. For example, the housing portions  104  and  106  might swivel relative to each other. 
       FIG. 2  shows a perspective view of Bluetooth enabled cellular telephone  135  and several user intervention mechanisms. The cellular telephone shown with respect to  FIG. 2  is similar to the cellular telephone shown with respect to  FIG. 1 , except that the cellular telephone  135  shown with respect to  FIG. 2  only has one housing portion  138 . It does not have a second, sliding portion. The cellular telephone  135  has a display screen  108 , a keypad  124  and a navigation keypad  112 . 
     The display screen has several menu entries  141  and  144  displaying various options for selection by the user. The user can press one of the keys on keypad  124  or navigation keypad  112  to select an option. Additionally, the user can navigate within the menu by pushing one of the keys on keypad  124  or navigation keypad  112 . For example, menu entry  141  may be highlighted or otherwise indicated, and the user may wish to select menu entry  144 . The user may navigate to entry  144  by pushing one of the keys and then select entry  144  by pushing one of the keys. One of the options  141  or  144  is an activate Bluetooth option  144 . The user can cause the Bluetooth module to enter an activity state by selecting the activate Bluetooth option  144 . Alternatively, the menu option  144  can be selected by speaking into microphone  126  if the cellular telephone  135  has a voice recognition module. 
     The menu is stored in a memory and generated for display on the display screen  108  by a processor. The processor and memory will be described more fully below, with respect to  FIG. 3 . 
     A communication adapter  147  is also shown with respect to  FIG. 2 . The communication adapter  147  connects to the cellular telephone  135  by plugging into communication connector  128 . The communication adapter  147  can be used to transfer data between the cellular telephone  135  and another electronic device (not shown), such as, for example, a computer. The communication adapter  147  may be, for example, a universal serial bus (USB) connector, or a serial data connector, or any other convenient type of communication adapter. The cellular telephone has a sensor connected to the communication connector  128  for sensing when a communication adapter  147  is connected to the communication connector. The Bluetooth module is connected to the sensor. When the communication adapter  147  is connected to the cellular telephone, the Bluetooth module is notified and the Bluetooth module enters an activity state, such as, for example, a page state. 
     A power adapter  151  is also shown with respect to  FIG. 2 . The power adapter  151  can be plugged into the cellular telephone at power connector  130  for providing power to the cellular telephone. As is well known, the power adapter may provide power to the processor the transceiver and the portable power supply, such as a battery. The power adapter  151  has a plug  155 , for connecting the power adapter to a power supply. The power supply may be a wall outlet, as is well known. Alternatively, the power supply may be an automobile. In that case, the plug  155  might be adapted to fit into an automobile lighter power supply, as is well known. In that case, the power adapter  151  would be a car power adapter. 
     The power connector  130  is connected to a power connection sensor  204 . When a power adapter  151  is connected to the cellular telephone  135 , the power connection sensor  204  senses the power adapter  151 . The power connection sensor  204  is connected to the Bluetooth module. In response to a signal from the power connection sensor  204 , the Bluetooth module enters an activity state. For example, the Bluetooth module may enter a page state or a page scan state. 
     In addition to plugging a communication adapter or a power adapter, the user intervention event might be plugging in an adapter that provides both communication and power. One device that provides both power and communication is a sync cradle. A sync cradle is a cradle for a cellular telephone that provides power and functionality for synchronizing various software on a the cellular telephone with software on another electronic device, such as, for example, synchronizing a scheduling program on the cellular telephone with a scheduling program on a computer. Plugging any device into the cellular telephone can be a user intervention event. 
     The various parts and functions of a Bluetooth enabled cellular telephone will now be described with respect to  FIG. 3 .  FIG. 3  shows a block diagram of a Bluetooth enabled cellular telephone  160 . The cellular telephone  160  includes an antenna  165  for communicating radio frequency RF signals over the air. The antenna  165  is connected to an RF circuit  170  for converting the RF signal to a digital signal and for converting a digital signal to an RF signal. The RF circuit may include, for example, any one or more of the following: a duplexer, a filter, a mixer and an RF amplifier. The RF circuit  170  includes a Bluetooth RF circuit and a cellular communication RF circuit. One or more of the components may be re-used between the Bluetooth circuit and the cellular communication circuit. The cellular communication circuit communicates cellular communication signals, such as, for example, U.S. PCS signals or GSM signals. Other communication signals are possible, such as, for example, U.S. cellular communication between 824 and 899 MHz. 
     One antenna  165  and one RF circuit  170  are shown. Other configurations are possible. For example, the cellular telephone may have one antenna for Bluetooth communication and another antenna for cellular communication. Alternatively, the cellular telephone may have an adaptable antenna or antennas that can be adapted to be used for cellular communications or for Bluetooth. 
     The RF circuit  170  is connected to a processor block  175 . The processor block performs many functions for the cellular telephone. The processor block demodulates and decodes the digital signal so that the signal can be sued by the cellular telephone. For example, if the cellular communication signal contains an audio signal, the processor block demodulates and decodes the digital signal to present the audio signal at a user interface device  180  such as a speaker. Only one user interface device is shown with respect to  FIG. 3 , but, at least four user interface devices are common on a cellular telephone, namely, a speaker  110 , a display screen  108 , a keypad  124  and a microphone  126 , shown with respect to  FIGS. 1 and 2 . Other user interface devices are possible. 
     The processor block  175  includes a cellular communication module  185  and a Bluetooth module  190 . The cellular communication module demodulates the digital cellular communication signals, as described above. The Bluetooth module  190  demodulates the Bluetooth signals and controls the states and modes of a Bluetooth state machine, which will be described with respect to  FIG. 4 . 
     As will be understood by those of skill in the art, the processor block  175  may include one or more processors. For example, the Bluetooth module functions may be controlled by a Bluetooth processor while the cellular communication functions may be controlled by a separate processor. Additionally, as is well known in the art, one or more of the functions and processes described herein may be performed by discreet logic or any other device such as, for example, a field programmable gate array (FPGA), separately or in conjunction with a processor. 
     The processor block  175  is connected to a memory block  195 . The memory block may include one or more memory components. The memory compon4ents may be any convenient type of memory, such as, for example, flash memory, random access memory, read only memory, volatile memory, non-volatile memory and removable memory. The memory block  195  stores the code and data necessary for the cellular telephone to perform the functions described herein and those functions that are known in the art. 
     The processor block  175  is also connected to a portable power supply  198 , such as, for example, a battery. The portable power supply provides power for the processor block  175 . The portable power supply  198  is also connected to the RF circuit  170 , for supplying power to the RF circuit. The portable power supply may be connected to other components, such as, for example, the user interface device  180 . As depicted in  FIG. 3 , the portable power supply is connected to the user interface device  180  through the processor block  175 . 
     The processor block  175  is also connected to three sensors, a communication sensor  200 , a power connection sensor  204  and a configuration sensor  208 . Specifically, the processor block is configured so that the Bluetooth module  190  receives notification if a communication adapter, a power adapter or a configuration change is sensed by the communication sensor  200 , the power connection sensor  204  or the configuration sensor  208 , respectively. As described above with respect to  FIGS. 1 and 2 , the Bluetooth module enters an activity state responsive to sensing a communication adapter, a power adapter or a configuration change. 
     The processor block  175  is also connected to communication connector  128  and power connector  130 . Sensors  200  and  204  are shown as separate from the processor block  175 . The sensors  200  and  204  may be separate from or included in the processor block  175 . For example, a power supply connection to power connector  130  may cause an electrical line connected to a processor in processor block  175  to sense a high voltage. Responsive to sensing the high voltage, the processor may cause the Bluetooth module to enter an activity state. 
       FIG. 4  shows a block diagram of a Bluetooth state machine  210 . The Bluetooth state machine is similar to known Bluetooth state machines, except that transitions between passive states and activity states are made in response to user intervention events. Transitioning between a passive state and an activity state is defined as waking up. In a standby state  220 , a Bluetooth state machine is on but not transmitting or receiving. The standby state is a passive state. From the standby state  220 , the state machine  210  can transition to a page state  230 , a page scan state  240 , an inquiry state  250  or an inquiry scan state  260 , all of which are activity states. Advantageously, the state machine  210  can make these transitions in response to a user intervention event. Thus, arrows  232 ,  242 ,  252  and  262  represent user intervention events. 
     From the page state  230 , the page scan state  240 , the inquiry state  250  and the inquiry scan state  260  the state machine can return to the standby state. Additionally, from each of states  230 ,  240 ,  250  and  260 , the state machine can enter the connection state  270 . The connection state  270  includes three modes, the active mode  280 , the sniff mode  290  and the hold mode  300 . The active mode  280  is an activity state, but the sniff mode  290  and the hold mode  300  are passive states. The state machine  210  can enter the active mode  280  from either the sniff mode  290  or the hold mode  300 , as represented by arrows  292  and  302 . State changes  292  and  302  represent user intervention events. 
     The state machine can enter the park state  310  from the connection state  270 . The park state  310  is a passive state. Additionally, the state machine  210  can enter the connection state  270  from the park state  310  as represented by arrow  312 . Advantageously, the state machine may transfer from the park state  310  to the connection state  270  in response to a user intervention event. 
     By making any one or more of the above described transitions from a passive state to an activity state in response to a user intervention event, the Bluetooth module conserves power or communication resources or both. Conserving communication resources may include reducing interference with other communication systems, such as, for example, 802.11 communication systems. 
     Further, while embodiments and implementations of the invention have been shown and described, it should be apparent that many more embodiments and implementations are within the scope of the invention. Accordingly, the invention is not to be restricted, except in light of the claims and their equivalents.