Abstract:
When wireless binding or pairing is required, two wireless devices change from a normal broad wireless operating range to a reduced wireless operating range. The wireless devices then conduct binding or pairing operations in the reduced wireless range. This prevents other wireless devices in the same area from detecting the same reduced range binding signaling and inadvertently binding with the wrong devices. After the reduced range binding operations are completed, the wireless devices automatically switch back to the broader normal wireless operating range and use the exchanged binding information for conducting normal wireless communications. The reduced range pairing scheme creates a simple and intuitive technique for pairing wireless devices without requiring the user to press buttons or select devices from a list.

Description:
BACKGROUND 
     Wired peripherals, such as keyboards, mice, game controllers, etc. are physically connected to a host computer by a cable. Wireless peripherals on the other hand are not physically connected to the host computer. Therefore wireless peripherals must be paired to the host to create a “virtual cable.” During the “pairing” or “binding” process, two wireless devices exchange device identifiers (IDs) and agree upon one of multiple wireless channels for transmitting information. The device IDs are sent along with the wireless transmissions so that the receiving device can confirm it is receiving data from the correct remote wireless device. 
     Today there are three main techniques for wirelessly pairing a peripheral with a desired host. The first technique requires a user to push buttons on the peripheral and host at the same time. This places both devices in a special pairing mode where the two devices exchange pairing information. The pairing button technique assumes that no other devices will be in the pairing mode at the same time. This is the typical technique used with most 27 Mega Hertz (MHz) wireless mice and keyboards. 
     The pairing buttons used for the pairing button technique add cost to the host and peripheral devices. The pairing buttons are usually placed in out of the way locations on the wireless devices and are relatively small so they are not accidentally pressed during normal wireless operations. Users are frustrated when they cannot find or activate these small out of the way pairing buttons. 
     A second pairing technique requires the wireless peripheral device to query all devices in range and present a list to the user. The peripheral user then selects the desired host from the displayed list. The list technique requires a user interface, which is not available on many low-cost peripheral devices. This technique also requires the user to know the name, or some other distinguishing characteristic, of the desired host in order to select it from the list of all in-range devices. 
     A third wireless system adds a near field communications transceiver to each wireless device that only transmits over a few centimeters. This technique requires additional transceiver hardware and additional firmware to control the special near field communications transceiver. The near field transceiver uses special wireless binding signals that are different from the signaling used for normal data communications. This adds additional wireless hardware to the system that is cost-prohibitive for many low-cost peripherals. 
     The present invention addresses this and other problems associated with the prior art. 
     SUMMARY OF THE INVENTION 
     When wireless binding or pairing is required, two wireless devices change from a normal broad wireless operating range to a reduced wireless operating range. The wireless devices then conduct binding or pairing operations in the reduced wireless range. This prevents other wireless devices in the same area from detecting the same reduced range binding signaling and inadvertently binding with the wrong devices. After the reduced range binding operations are completed, the wireless devices automatically switch back to the broader normal wireless operating range and use the exchanged binding information for conducting normal wireless communications. The reduced range pairing scheme creates a simple and intuitive technique for pairing wireless devices without requiring the user to press buttons or select devices from a list. 
     The foregoing and other objects, features and advantages of the invention will become more readily apparent from the following detailed description of a preferred embodiment of the invention which proceeds with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram showing two wireless devices switching from a normal wireless operating range to a reduced binding range. 
         FIG. 2  is a diagram showing the wireless devices conducting binding operations while operating in the reduced binding range. 
         FIG. 3  is a diagram showing the two wireless devices switching back to the normal operating range. 
         FIG. 4  shows a diagram comparing one example of the normal operating range with the reduced binding range. 
         FIG. 5  is a sequence diagram showing the operations performed by the wireless devices. 
         FIG. 6  is a detailed block diagram of the wireless communication circuitry inside the wireless devices. 
         FIG. 7  is a diagram of a wireless Universal Serial Bus (USB) device that uses the reduced binding range to bind with a USB host. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows a host device  12  that in this example is a Personal Computer (PC) and a peripheral device  14  that in this example is a computer mouse. These of course are just examples and the host device  12  and the peripheral device  14  can be any devices that need to wirelessly communicate with each other. For example, the wireless peripheral device  14  can be a game console, toy, keyboard, wireless sensors, etc. that needs to communicate with a computer, television, stereo, server, or other type of host computing device  12 . 
     The peripheral device  14  includes wireless communication circuitry  15  that is used to wirelessly communicate with wireless communication circuitry  13  in host device  12 . The wireless communication circuitry  13  and  15  is described in more detail below in  FIG. 6  but can be any type of wireless communication circuitry, such as the type used for Bluetooth, IEEE 802.11, or for any other type of wireless communications. 
     The peripheral device  14  and the host device  12  conduct normal data and message communications over what is referred to as a normal wireless operating range  16 . The normal wireless operating range  16  refers to the range of distances that the host device  12  and peripheral device  14  are normally spaced apart when conducting wireless communications. The normal wireless operating range  16  also refers to the wireless signal amplification levels or power levels normally used in the wireless devices  12  and  14  when conducting normal data and message communications. 
     When the peripheral device  14  is not currently wirelessly connected to the host device  12 , or has never been wirelessly connected to the host device  12 , the peripheral device  14  automatically reduces its normal operating range  16  to a reduced binding mode range  20 . In other embodiments, the peripheral device  14  may switch to the reduced binding mode range  20  whenever it first powers up or whenever it does not currently know the wireless identification number of host device  12 . Alternatively, the peripheral device  14  may switch to the reduced binding range  20  when a button  19  is pressed by a user. 
     The reduced binding range  20  refers to a reduced narrower range of distances that the peripheral device  14  must be physically located next to the host device  12  in order to conduct wireless communications. In one example, the peripheral device  14  switches to the reduced binding range  20  by reducing the amplification level of signals transmitted from the wireless communication circuitry  15 . 
     While in the reduced binding range  20 , the peripheral device  14  sends a bind channel change request message  22  on all channels  24  requesting any in-range host device to enter a pairing or binding mode. All channels  24  include any channels that host device  12  may be currently operating on. Because the peripheral device  14  is transmitting at a low power level, the bind channel change request  22  can only be successfully processed by a host device  12  that is in relatively close proximity to peripheral device  14 . Thus, a binding handshake exchange can be initiated simply by a user moving the peripheral device  14  close to the desired host device  12 . 
     In one example, the reduced binding range  20  may be somewhere around 6-12 inches or in other words around 15-30 centimeters. Reducing the communication range  20  to inches, reduces the possibility that the peripheral device  14  may unintentionally pair with the wrong host device. 
     In one example, the host device  12  successfully receiving the bind channel change request message  22  may also reduce the transmit power level and/or receive sensitivity of communication circuitry  13 . This is done in one embodiment by reducing the amplification level of the transmit and/or receive signals in the wireless communication circuitry  13 . 
     The host device  12  and the peripheral device  14  then each enter a pairing or binding mode where each configure their wireless communication circuitry  13  and  15 , respectively, to operate on a particular bind channel. In one example, this may be a predetermined channel only used for binding operations. For example, in current spread spectrum wireless systems, this could be channel  78  while channels  0 - 77  are used for normal communications. Of course any predefined channel can be used. In an alternative embodiment, the bind channel change request  22  can identify the bind channel that the two devices  12  and  14  should use for conducting binding operations. 
     The bind channel change request  22  notifies the host device  12  to change to the bind mode. In addition to operating at a reduced binding range  20 , wirelessly sending the bind channel change request  22  is also new. In previous binding systems, a binding button had to be pressed in order to initiate binding operations in the host computer. 
       FIG. 2  shows the operations that are performed by the peripheral device  14  and the host device  12  while in the binding mode and while operating in the reduced binding range  20 . In the binding mode, the peripheral device  14  and host device  12  send conventional binding messages  24 ,  26 , and  28 , but at a greatly reduced range that can only be successfully received by another wireless device in relatively close proximity. 
     Bind request  24  causes the host device  12  to send back a bind response  26  that identifies a wireless channel for conducting normal wireless communications. The response  26  also includes an identifier that is used by the peripheral device  14  to identify wireless communications from host device  12 . The peripheral device  14  then sends a final control response  28  back to the host device  12  that acknowledges the previous bind response  26  and causes both the peripheral device  14  and the host device  12  to revert back to a normal operating mode. A Light Emitting Diode (LED)  21  may then be activated on the peripheral or host device  14  to notify the user that the binding operations were successfully completed. 
       FIG. 3  shows the peripheral device  14  and host device  12  after they have switched back to the normal wireless operating range  16 . The peripheral device  14  and the host device  12  each switch their communication circuitry  15  and  13  to operate on the channel  30  identified during the binding session in  FIG. 2 . The communication circuitry  13  and  15  increase their transmit and receive signal strengths back to normal operational power levels. This allows wireless communications  32  at the normal wireless operating range  16 . 
       FIG. 4  shows a diagram of the normal operating range  16  that is used for normal communications between the peripheral  14  and the host device  12 . In one example, when both the peripheral device  14  and the host device  12  operate at normal transmit and receive signal strengths, the normal wireless operating range  16  is around 10-20 meters. In one example, when the transmit or receive signal strengths are reduced in the peripheral device  14  and the host device  12 , the reduced binding range  20  is somewhere around, or less than, 6-12 inches or equivalently around, or less than, 15-30 centimeters (cms). These are only examples of the different operating ranges  16  and  20 . The normal transmit or received signal strengths and the corresponding amount of signal strength reduction can be varied according to the desired operating parameters of the wireless system. 
     There is less likelihood that other wireless devices will mistakenly respond to the binding messages when the wireless devices operate in the reduced binding range  20 . This allows a user to pair two wireless devices simply by moving the two devices close together. This is a more intuitive method for pairing a peripheral device with a host device, is more user-friendly, and results in lower cost. 
       FIG. 5  is a sequence diagram describing in further detail the operations performed by the peripheral device  14  and the host device  12  while in the reduced binding range  20 . At stage  40  the peripheral device  14  enters the bind mode. As explained above, at initial power up, the peripheral device may not have a host device ID or operating channel configured for sending wireless communications. Alternatively, a current wireless configuration may no longer be operational. For example, the peripheral device  14  may not receive some number of responses back from the host device  12  over the currently configured communication channel. If any of these events happen, the peripheral device reduces its communications range as shown in  FIGS. 1 and 2 . 
     At stage  42 , the peripheral device  14  sends out the bind channel change request packet  22  on each channel that the host device  12  might possibly be operating on. At stage  44 , the host device  12  receives the bind channel change request packet  22  on one of the channels and accordingly changes its wireless communication circuitry  13  ( FIG. 1 ) to start transmitting and receiving messages on the bind channel. At stage  46 , the peripheral device  14  has completed sending the bind channel change request packet  22  on each channel. The peripheral device  14  then configures its local wireless communication circuitry  15  to start transmitting and receiving messages on the bind channel. 
     At stage  48 , the peripheral device  14  and the host device  12  exchange conventional bind mode messages as previously described in  FIG. 2 . The bind request packet  24  solicits a bind response  26  from host device  12 . However, in a novel operation, the host device  12  checks the received signal strength associated with bind request packet  24 . The host  12  may successfully receive the bind request packet  24 . However, the host might not respond if the bind request packet  24  has a received signal strength below some predefined threshold. This prevents two host devices that are in close proximity from trying to bind to the same peripheral device. 
     If a received signal strength indication (RSSI) level is above the predefined threshold, the host device  12  sends the bind response packet  26  back to the peripheral device  14 . The bind response packet  26  identifies to the peripheral device  14  the channel that is going to be used for normal communications and also provides a host device identifier value. The peripheral device  14  then provides an acknowledge and any other necessary control information back to the host device  12  in control response packet  28 . At stage  50  the peripheral device  14  and host device  12  both exit the bind mode and start operating on the identified channel at the normal operating range  16  as previously shown in  FIG. 3 . The peripheral device  14  may also activate the LED  21  ( FIG. 1 ). 
       FIG. 6  shows in more detail the wireless communication circuitry  13  or  15  operating in the host device  12  or peripheral device  14 , respectively. The host device  12  and peripheral device  14  each include a micro-processor unit (MCU)  54  that controls the operation of radio circuitry  52 . The radio circuitry  52  can be any conventional transceiver that transmits and receives wireless signals. The MCU  54  sends data  58  to the radio circuitry  52  that is then encoded into wireless signals and transmitted over one of the available wireless channels. Similarly, any signals received over the wireless channel by the radio circuitry  52  is decoded into digital data that is then sent to the MCU  54  for additional processing. 
     The MCU  54  outputs a signal strength control signal  56  that is used by the radio circuitry  52  to adjust the amplification of the transmitted and/or received wireless signals. For example, a lower value is sent on signal strength signal  56  when the MCU  54  wants the radio circuitry  52  to operate in the reduced binding range  20 . Radio circuitry  52  then varies the amplification of transmit or receive signals according to signal  56 . Radio circuitry  52  is known to those skilled in the art and is therefore not described in further detail. 
     A receive signal strength monitor  60  can be used by the host device  12  to identify a received signal strength during the binding mode operations. As described above, if the received signal strength of the bind channel change request packet  22  or the bind request packet  24  ( FIG. 5 ) is below a predetermined threshold level, the host device  12  may ignore the received packet. This further prevents binding between the wrong wireless devices. 
     In one example, the radio circuitry  52  transmits wireless signals using a Bluetooth, 802.11, or some other spread spectrum transmission protocol. However it should be understood that the reduce binding range can be used with any wireless system that needs to perform binding operations. 
     The MCU  54  is configured to operate the same radio circuitry  52  in both the normal communications range  16  and in the reduced binding range  20 . As described above, the MCU  54  automatically operates the radio circuitry  52  in the reduced binding range  20  when the radio circuitry needs to be paired with a remote wireless device and operates the radio circuitry  52  in the normal communications range when the radio circuit is successfully paired with the remote wireless device  14 . 
     The MCU  54  changes between the different channels by varying the channel signal value  57  and controls the sending of the bind channel change request packets  22  on each of the plurality of different wireless channels. The MCU  54  also switches the radio circuitry  52  to start operating on the bind channel by setting an associated channel value  57  and performs the other operations described in  FIG. 5 . After binding operations have been successfully completed, the MCU  54  may activate LED  21  for some period of time. 
     The reduced range pairing operation does not require any additional radio circuitry or other hardware. For example, no additional buttons or near-field communications transceivers are required. A user does not have to fumble with small obscurely-placed buttons or confusing lists of hosts. Reduced range pairing is simple for a user to understand and also reduces the possibility of the peripheral pairing with the wrong host, which is more of a possibility with the button and list techniques. 
     Other ways to reduce the effective communication range between the peripheral device  14  and the host device  12 , include bypassing the antenna  55 . Additional hardware could also be used to trigger the devices  12  and  14  to enter the pairing mode. For example, a magnetic reed switch could be used as a trigger to indicate when the peripheral device  14  is held close enough to the host device  12  for conducing the bind operations. The host device  12  could include a large magnet that activates the magnetic reed switch when the two devices are within binding range. 
       FIG. 7  shows another embodiment where the reduced binding range  20  is used when a Universal Serial Bus (USB) device  70  needs to bind to a USB host  84 . In this example, the USB device  70  is a wireless game controller. The game controller includes a USB controller  72  for sending or receiving USB messages. A radio circuit  74  converts the USB messages into radio signals that are transmitted to a wireless dongle  76 . The dongle  76  includes radio circuitry  78  that is controlled by a MCU  80 . The MCU connects to a USB port  82  on a host computer  84 . The radio circuitry  74  and  78  and the processors  72  and  80  operate in a manner similar to the radio circuitry  52  and MCU  54  in  FIG. 6 . 
     The commands generated by the game controller  70  are converted by the USB controller  72  into USB messages that are transmitted via radio circuitry  74  and  78  to the MCU  80 . The MCU  80  then sends the USB messages over USB port  82  to the USB host computer  84 . During a binding operation, a user simply places the game controller  70  within some minimum distance from dongle  76 . The two controllers  72  and  80  then automatically reduce their operating range and conduct the binding operations described above. The user can then move the game controller  70  back to some conventional wireless operating distance and start performing normal wireless game controller operations. 
     The system described above can use dedicated processor systems, micro controllers, programmable logic devices, or microprocessors that perform some or all of the operations. Some of the operations described above may be implemented in software and other operations may be implemented in hardware. 
     For the sake of convenience, the operations are described as various interconnected functional blocks or distinct software modules. This is not necessary, however, and there may be cases where these functional blocks or modules are equivalently aggregated into a single logic device, program or operation with unclear boundaries. In any event, the functional blocks and software modules or features of the flexible interface can be implemented by themselves, or in combination with other operations in either hardware or software. 
     Having described and illustrated the principles of the invention in a preferred embodiment thereof, it should be apparent that the invention may be modified in arrangement and detail without departing from such principles. I claim all modifications and variation coming within the spirit and scope of the following claims.