Patent Application
20160081019
The present embodiments relate generally to wireless devices, and specifically to reducing power consumption in wireless devices.
A wireless network may include two or more wireless devices. The wireless network may be operating in an infrastructure mode and may be administered by an access point, or may be operating in an ad hoc or peer-to-peer mode and may be administered by one or more group owners.
Connecting to and/or administering the wireless network consumes power, even during times when there is little or no network activity. For example, access points and peer-to-peer group owners may periodically send (e.g., broadcast) a Wi-Fi beacon during each beacon period. Sending the Wi-Fi beacon and actively listening for any Wi-Fi messages in response to the Wi-Fi beacon consumes power, even when there are no Wi-Fi messages to receive. When the wireless device is a mobile wireless device, power consumption may undesirably decrease battery life.
Thus, there is a need to reduce the power consumption of wireless devices, particularly when there is little or no network traffic in the wireless network.
This Summary is provided to introduce in a simplified form a selection of concepts that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter.
Devices and methods for reducing power consumption by a wireless device are disclosed. In accordance with the present embodiments, a first wireless device may receive a Wi-Fi message by establishing a BLUETOOTH low energy (BLE) connection between the first wireless device and a second wireless device. The first wireless device may operate in a low-power mode and may receive a BLE message from the second wireless device. The first wireless device may leave the low-power mode and enter a normal operating mode based, at least in part, on the received BLE message. The first wireless device may then receive the Wi-Fi message from the second wireless device.
In other embodiments, a first wireless device may scan for a Wi-Fi network by establishing a BLUETOOTH low energy (BLE) connection between the first wireless device and a second wireless device. The first wireless device may operate in a low-power mode and may receive a BLE message from the second wireless device. The first wireless device may leave the low-power mode and enter a normal operating mode based, at least in part, on the received BLE message. The first wireless device may then scan for the Wi-Fi network.
In still other embodiments, a first wireless device may establish a BLUETOOTH low energy (BLE) connection between the first wireless device and a second wireless device. An association database may be maintained at the first wireless device. A synchronized BLE message may be sent to the second wireless device based, at least in part, on the association database. For at least one embodiment, the association database may include at least one of a station association identification number, a station internet protocol address and a BLUETOOTH identification number associated with the second wireless device.
The present embodiments are illustrated by way of example and are not intended to be limited by the figures of the accompanying drawings. Like numbers reference like elements throughout the drawings and specification.
The present embodiments are described below in the context of Wi-Fi enabled devices for simplicity only. It is to be understood that the present embodiments are equally applicable for devices using signals of other various wireless standards or protocols. As used herein, the terms “wireless local area network (WLAN)” and “Wi-Fi” can include communications governed by the IEEE 802.11 standards, BLUETOOTH®, HiperLAN (a set of wireless standards, comparable to the IEEE 802.11 standards, used primarily in Europe), and other technologies used in wireless communications. Further, the terms “low-power mode” may refer to a low-power operating mode in which one or more components of a Wi-Fi device or station are deactivated (e.g., to prolong battery life), and thus the terms “low-power state” and “power save state” may be used interchangeably herein.
In the following description, numerous specific details are set forth such as examples of specific components, circuits, and processes to provide a thorough understanding of the present disclosure. The term “coupled” as used herein means coupled directly to or coupled through one or more intervening components or circuits. Also, in the following description and for purposes of explanation, specific nomenclature is set forth to provide a thorough understanding of the present embodiments. However, it will be apparent to one skilled in the art that these specific details may not be required to practice the present embodiments. In other instances, well-known circuits and devices are shown in block diagram form to avoid obscuring the present disclosure. Any of the signals provided over various buses described herein may be time-multiplexed with other signals and provided over one or more common buses. Additionally, the interconnection between circuit elements or software blocks may be shown as buses or as single signal lines. Each of the buses may alternatively be a single signal line, and each of the single signal lines may alternatively be buses, and a single line or bus might represent any one or more of a myriad of physical or logical mechanisms for communication between components. The present embodiments are not to be construed as limited to specific examples described herein but rather to include within their scope all embodiments defined by the appended claims.
In some embodiments, wireless network 100 may include a wireless device operating as an access point (AP) for wireless networks operating in the infrastructure mode, or as a peer-to-peer group owner (P2PGO) for wireless networks operating in the ad hoc or the peer-to-peer mode. The AP or P2PGO (shown as AP/P2P Group Owner 101 in
Wireless network 100 may include a wireless device operating as a station (STA) for wireless networks operating in the infrastructure mode, or as a peer-to-peer client (P2P client) for wireless networks operating in the ad hoc or the peer-to-peer mode. The STA or P2P client (shown as STA/P2P client 102 in
AP/P2PGO 101 and STA/P2P client 102 may also include BLUETOOTH® transceivers (not shown for simplicity) to send and receive BLUETOOTH messages. In some embodiments, the BLUETOOTH transceivers may also send and receive BLUETOOTH Low Energy (BLE) messages. Operation of AP/P2PGO 101 and STA/P2P client 102 with respect to BLE messages is described in more detail below in conjunction with
Application processor 250 may be coupled to BLUETOOTH transceiver 220 and Wi-Fi transceiver 230. In some embodiments, application processor 250 receives data from and/or provides data to Wi-Fi transceiver 230 and/or BLUETOOTH transceiver 220. For example, Wi-Fi transceiver 230 may receive Wi-Fi messages from another wireless device (not shown for simplicity) and may provide the received data to the application processor 250. In another example, BLUETOOTH transceiver 220 may receive BLE messages from another wireless device and may provide the received data to the application processor 250.
Controller 210 may be coupled to BLUETOOTH transceiver 220, Wi-Fi transceiver 230, and application processor 250. In some embodiments, controller 210 may control operations of BLUETOOTH transceiver 220 and Wi-Fi transceiver 230. For example, controller 210 may cause Wi-Fi transceiver 230 to send Wi-Fi messages including Wi-Fi beacons to other wireless devices. Controller 210 may also cause BLUETOOTH transceiver 220 to send one or more BLE messages to other wireless devices. In some embodiments, controller 210 may cause BLUETOOTH transceiver 220 to send one or more BLE messages synchronized to Wi-Fi beacons sent (e.g., broadcast) by Wi-Fi transceiver 230. The synchronized BLE message (when received by BLUETOOTH transceiver 220 from another wireless device) may cause portions of wireless device 200 to enter or leave a low-power mode. For example, the synchronized BLE message may cause controller 210 to provide a mode_cntl signal 240 to Wi-Fi transceiver 230 and application processor 250. The mode_cntl signal 240 may determine whether Wi-Fi transceiver 230 and/or application processor 250 is in the low-power mode. Operation of controller 210, BLUETOOTH transceiver 220, Wi-Fi transceiver 230, application processor 250, and mode_cntl signal 240 is described below in more detail in conjunction with
Memory 340 may include a BLE association database 342 that may be used to associate several identification numbers with a particular wireless device. In some embodiments, the wireless device 300 may be identified by a station association identification (AID) number, a station internet protocol address (IP ADDR) and a BLUETOOTH identification number. Table 1 shows example entries in the BLE association database 342.
The BLE association database 342 may allow a user and/or program to identify a particular wireless device from at least one of the entries within the BLE association database 342. In some embodiments, data for the BLE association database 342 may be provided by STAs and/or P2P clients of wireless network 100. In other embodiments, data for the BLE association database 342 may be provided by the user through a user operable interface (not shown for simplicity) associated with wireless device 300.
Further, memory 340 may also include a non-transitory computer-readable storage medium (e.g., one or more nonvolatile memory elements, such as EPROM, EEPROM, Flash memory, a hard drive, etc.) that may store the following software modules:
Processor 330, which is coupled to BLUETOOTH transceiver 220, Wi-Fi transceiver 230, and memory 340, may be any suitable processor capable of executing scripts or instructions of one or more software programs stored in the wireless device 300 (e.g., within memory 340).
Processor 330 may execute BLUETOOTH communication module 344 to send and/or receive BLUETOOTH messages, including BLE messages. In some embodiments, transmitting and/or receiving BLE messages may consume less power than transmitting and/or receiving BLUETOOTH messages. Some BLE messages may include informational elements that may provide status information regarding a wireless device. For example, a BLE message may include an informational element to indicate that wireless device 300 is sending a Wi-Fi message after the next Wi-Fi beacon. In another example, another BLE message may include an informational element to indicate that a subsequent Wi-Fi message is directed to a particular wireless device. In some embodiments, BLUETOOTH communication module 344 may determine a receive signal strength value associated with received BLUETOOTH and/or BLE messages.
Processor 330 may execute Wi-Fi communication module 346 to send and/or receive Wi-Fi messages, including Wi-Fi beacons. Wi-Fi communication module 346 may also control a power mode of Wi-Fi transceiver 230 through transceiver power controller 232 (see also
Processor 330 may execute wireless device management module (WDMM) 348 to control at least some operations of BLUETOOTH communication module 344 and/or the Wi-Fi communication module 346. In some embodiments, WDMM 348 may synchronize transmission of some BLE messages with Wi-Fi beacons. For example, WDMM 348 may cause BLUETOOTH communication module 344 to send a synchronized BLE message to one or more wireless devices prior to when Wi-Fi communication module 346 causes Wi-Fi transceiver 230 to send a Wi-Fi beacon. The synchronized BLE message may cause Wi-Fi transceiver 230 to enter or leave a low-power mode as described below in more detail in conjunction with
Next, AP/P2PGO 101 enters a low-power mode (403). In some embodiments, in response to entering the low-power mode, mode_cntl signal 240 may reduce power consumption by turning off a portion of Wi-Fi transceiver 230 included in AP/P2PGO 101. For example, analog and/or digital portions of Wi-Fi transceiver 230 associated with receiving a Wi-Fi message may be placed in a low-power mode and/or turned off. In other embodiments, other portions of AP/P2PGO 101 such as application processor 250 may be placed in the low-power mode.
Next, STA/P2P client 102 sends a synchronized BLE message indicating a Wi-Fi message status to AP/P2PGO 101 (405). In some embodiments, the BLE message is synchronized to a periodic Wi-Fi beacon sent by the AP/P2PGO 101. For example, prior to when AP/P2PGO 101 sends the Wi-Fi beacon, STA/P2P client 102 may send the synchronized BLE message. In some embodiments, the synchronized BLE message may include one or more informational elements indicating Wi-Fi message status. For example, a synchronized BLE message may include an informational element that may indicate whether STA/P2P client 102 has a Wi-Fi message for AP/P2PGO 101. In some embodiments, STA/P2P client 102 may determine a receive signal strength value associated with the synchronized BLE message or a BLE acknowledgment message (possibly sent by AP/P2PGO 101 in response to receiving the synchronized BLE message). The receive signal strength value may be used to determine a transmit output power of a Wi-Fi message transmitted by STA/P2P client 102 to AP/P2PGO 101.
Next, AP/P2PGO 101 determines if the synchronized BLE message is received (407). Since the BLE message is synchronized (in some embodiments, synchronized to the Wi-Fi beacon), the AP/P2PGO 101 may predict when the BLE message may be received. If the synchronized BLE message is received, then AP/P2PGO 101 may determine if the synchronized BLE message indicates that STA/P2P client 102 has a Wi-Fi message for AP/P2PGO 101 (409). In some embodiments, the AP/P2PGO 101 may determine if the synchronized BLE message includes an informational element indicating that STA/P2P client 102 has a Wi-Fi message for AP/P2PGO 101. In some other embodiments, the AP/P2PGO 101 may determine a receive signal strength value associated with the received synchronized BLE message. The receive signal strength value may be used to determine a transmit output power of a Wi-Fi message transmitted by AP/P2PGO 101 to STA/P2P client 102. If the synchronized BLE message indicates that STA/P2P client 102 does not have a Wi-Fi message, then AP/P2PGO 101 remains in the low-power mode (411). Thus, AP/P2PGO 101 may continue to reduce power consumption because there is no Wi-Fi message to receive from STA/P2P client 102. Operations proceeds to 405.
If the synchronized BLE message indicates that STA/P2P client 102 has a Wi-Fi message for AP/P2PGO 101 (as tested at 409), then AP/P2PGO 101 enters the normal operating mode (413). In some embodiments, in response to entering the normal operating mode, mode_cntl signal 240 may return power to application processor 250 and/or portions of Wi-Fi transceiver 230 that may have been previously in a low-power mode. For example, analog and digital portions of Wi-Fi transceiver 230 associated with receiving Wi-Fi messages may return to their operational modes.
Next, STA/P2P client 102 sends the Wi-Fi message to AP/P2PGO 101 (415). For example, STA/P2P client 102 may send data through a Wi-Fi message to AP/P2PGO 101. In some embodiments, the transmit output power associated with the Wi-Fi message may be based, at least in part, on a receive signal strength value associated with a BLE message received from AP/P2PGO 101. For example, a relatively low transmit output power may be used when a relatively high receive signal strength value is determined. In another example, a relatively high transmit output power may be used when a relatively low receive signal strength value is determined. Next, AP/P2PGO 101 receives the Wi-Fi message from STA/P2P client 102 (417). For example, AP/P2PGO 101 may receive data through a Wi-Fi message from STA/P2P client 102. Next, AP/P2PGO 101 may return to the low-power mode (419). In some embodiments, AP/P2PGO 101 may return to the low-power mode to reduce power consumption. Operations proceed to 405.
If AP/P2PGO 101 does not receive the synchronized BLE message (as tested at 407), then operations proceed to 413, and the AP/P2PGO 101 enters the normal operating mode. If the synchronized BLE message is not received (because of, for example, noise or interference present when trying to receive the synchronized BLE message), then AP/P2PGO 101 may enter the normal operating mode as a precaution so as not to miss Wi-Fi traffic that may be sent to AP/P2PGO 101. Since the BLE message is synchronized, a missing (e.g., not received) BLE message may be relatively easy to detect.
Next, AP/P2PGO 101 sends a synchronized BLE message to STA/P2P client 102 indicating a Wi-Fi beacon status (505). As described above in
Next, STA/P2P client 102 determines if the synchronized BLE message from AP/P2PGO 101 is received (507). As described above, since the BLE message is synchronized, the STA/P2P client 102 may predict when the BLE message may be received. If the BLE message is not received (because, for example, the AP/P2PGO 101 is out of range or in a low-power mode), then STA/P2P client 102 determines if a timer or a user initiates a network scan (509). In some embodiments, a timer may periodically initiate a network scan. For example, STA/P2P client 102 may have entered a new network and the user may want to connect to the new network. By periodically (e.g., under timer control) performing a network scan, new networks may be discovered while still reducing power consumption. In another example, the user may want to initiate a network scan because the user is aware that STA/P2P client 102 has entered a new network area. In one embodiment, if the STA/P2P client 102 is a smart phone, then the user may initiate a network scan by activating the smart phone display.
If a timer or a user initiates a network scan (as tested in 509), then STA/P2P client 102 enters the normal operating mode (513). In some embodiments, mode_cntl signal 240 may return power to application processor 250. Next, in response to entering the normal operating mode, the mode_cntl signal 240 may be cause STA/P2P client 102 to scan for available networks via Wi-Fi transceiver 230 (515).
Next, STA/P2P client 102 may remain or return to the low-power mode (517). The network scan may be complete, and therefore STA/P2P client 102 may return to the low-power mode to reduce power consumption. In some embodiments, in response to entering the low-power mode, mode_cntl signal 240 may cause STA/P2P client 102 to reduce power consumption by not performing network scans. In other embodiments, mode_cntl signal 240 may cause application processor 250 to enter a low-power mode. Operations proceed to 505.
If a timer or a user does not initiate a network scan (as tested in 509), then operations proceed to 517. The STA/P2P client 102 may continue to reduce power consumption by remaining in the low-power mode. If STA/P2P client 102 determines that the synchronized BLE message is received (as tested at 507), then STA/P2P client 102 determines if the synchronized BLE message indicates that a Wi-Fi beacon is forthcoming (511). For example, an informational element within the synchronized BLE message may indicate that AP/P2PGO 101 is to send a Wi-Fi beacon. If STA/P2P client 102 determines that BLE message indicates that there is a forthcoming Wi-Fi beacon, then operations proceed to 513. If STA/P2P client 102 determines that the synchronized BLE message does not indicate that there is a forthcoming Wi-Fi beacon, then operations proceed to 517.
First, a BLE connection is established between AP/P2PGO 101 (601A) and STA/P2P 102 client (601B). The BLE connection may be established in a manner similar to 401A and 401B described above in
Next, STA/P2P client 102 enters the low-power mode (603). In some embodiments, in response to entering the low-power mode, the mode_cntl signal 240 may reduce power consumption of STA/P2P client 102 by turning off a portion of Wi-Fi transceiver 230. For example, analog and digital portions of Wi-Fi transceiver 230 associated with receiving and/or sending Wi-Fi messages may be placed in a low-power mode via mode_cntl signal 240. In other embodiments, other portions of STA/P2P client 102 may be placed in a low-power mode and/or turned off. For example, application processor 250 may also be placed in a low-power mode.
Next, AP/P2PGO 101 maintains BLE association database 342 (605). As described in Table 1 above, in some embodiments, BLE association database 342 may associate a station association identification (AID) number, a station internet protocol address, and a BLUETOOTH identification number with a STA/P2P client. Thus, AP/P2PGO 101 may identify a particular STA/P2P client through BLE association database 342.
Next, AP/P2PGO 101 sends a synchronized BLE message to STA/P2P client 102 (607). As described above, in some embodiments, the BLE message may be synchronized to the periodic Wi-Fi beacons sent by the AP/P2PGO 101. A recipient of the synchronized BLE message may be determined based, at least in part, on BLE association database 342. For example, AP/P2PGO 101 may have a directed Wi-Fi message, such as an address protocol resolution message, for a particular STA/P2P client 102. AP/P2PGO 101 may determine which particular STA/P2P client 102 receives the directed Wi-Fi message using BLE association database 342. In another example, the directed Wi-Fi message may be any technically feasible unicast or multi-cast Wi-Fi message. In some embodiments, the synchronized BLE message may include an informational element indicating that a Wi-Fi message is forthcoming for the STA/P2P client 102 based on the BLE association database 342.
Next, STA/P2P client 102 determines if the synchronized BLE message from AP/P2PGO 101 is received (609). Since the BLE message is synchronized and periodic, the STA/P2P client 102 may predict when the synchronized BLE message may be received. If the synchronized BLE message is received, then STA/P2P client 102 determines if the BLE message indicates that a Wi-Fi message is forthcoming from AP/P2PGO 101 (611). In some embodiments, STA/P2P client 102 may determine whether the BLE message includes an informational element to indicate that the Wi-Fi message is forthcoming. If the BLE message indicates that a Wi-Fi message is forthcoming, then STA/P2P client 102 enters the normal operating mode (613). In some embodiments, in response to entering the normal operating mode, mode_cntl signal 240 may cause portions of STA/P2P client 102 to receive power. For example, through mode_cntl signal 240, the normal operating mode may return full power to portions of Wi-Fi transceiver 230 that may have previously been in a low-power mode. In another example, mode_cntl signal 240 may return full power to application processor 250.
Next, AP/P2PGO 101 may send the Wi-Fi message to STA/P2P client 102 (615). In some embodiments, the Wi-Fi message may include an address resolution protocol message for STA/P2P client 102. In other embodiments, the Wi-Fi message may include any feasible unicast or multicast Wi-Fi message. Next, STA/P2P client 102 receives the Wi-Fi message from AP/P2PGO 101 (617). Operations proceed to 603.
If the synchronized BLE message does not indicate that a Wi-Fi message is forthcoming (as tested at 611), then operations proceed to 603. Since there is no forthcoming Wi-Fi message, STA/P2P client 102 may continue to reduce power consumption by remaining in the low-power mode.
If synchronized BLE message is not received (as tested at 609), then operations proceed to 613. In some embodiments, the synchronized BLE message may not be received due to noise or interference. However, since the BLE message is synchronized, a missing (e.g., not received) BLE message may be relatively easy to determine. To ensure that STA/P2P client 102 may receive any Wi-Fi messages that may be sent, STA/P2P client 102 may enter the normal operating mode as described above.
In the foregoing specification, the present embodiments have been described with reference to specific exemplary embodiments thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader scope of the disclosure as set forth in the appended claims. The specification and drawings are, accordingly, to be regarded in an illustrative sense rather than a restrictive sense.
