Method and system for a fast power control mechanism for bluetooth devices

Aspects of a method and system for a fast power control mechanism for Bluetooth devices may include receiving from a first Bluetooth device, a request for a transmit power adjustment for one or more operating modes. A step size may be received for the transmit power adjustment via the received request. The transmit power may be adjusted as a function of the step size. A feedback message may be sent to the first Bluetooth device, wherein the feedback message may indicate a status of the adjusting. The transmit power adjustment may be requested via a Link Management Protocol (LMP) message. One or more operating modes may comprise a Bluetooth Basic Rate (BR) mode, and/or a Bluetooth Enhanced Data Rate (EDR) mode.

The above referenced application is hereby incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

Certain embodiments of the invention relate to signal processing for communication systems. More specifically, certain embodiments of the invention relate to a method and system for a fast power control mechanism for Bluetooth devices.

BACKGROUND OF THE INVENTION

Bluetooth wireless technology offers personal connectivity and provides freedom from wired connections. Bluetooth is a specification for a small form-factor, low-cost radio solution providing links between mobile computers, mobile phones and other portable, handheld devices.

Bluetooth wireless technology is an international, open standard for allowing intelligent devices to communicate with each other through wireless, short-range radio links. This technology allows Bluetooth compliant devices such as computers, cell phones, keyboards and/or headphones to establish connections, without wires, cables or any direct action from a user. Bluetooth is currently incorporated into numerous commercial products including laptops, Personal Digital Assistants (PDAs), cell phones, and printers, with more products being released every day.

Modern portable devices increasingly provide converged functionality of many devices that used to be separate entities. For example, it is now common to find PDA, cell phone and portable music player converged into a single device. Such multi-modal devices often comprise a variety of functional blocks to fulfill various tasks and several functional blocks and/or chipsets may access Bluetooth functionality.

A Bluetooth system normally comprises a Bluetooth host that may be part of a functional block, and a Bluetooth host controller. The Bluetooth host may, for example, be a GSM (Global System for Mobile Communications) chipset or functional block. The Bluetooth host provides a high level interface between a Bluetooth command set and a core application furnished by the Bluetooth host. A Bluetooth host may be coupled to a Bluetooth host controller via a host controller interface (HCI). The Bluetooth host controller comprises the baseband and RF portion of the Bluetooth system, that is, the actual radio part that may be connected to the Bluetooth antenna. If, for example, the Bluetooth host is a GSM block and there is also a multimedia decoder block that may need to stream music to a pair of Bluetooth headphones, the multimedia decoder will send the audio data to the Bluetooth Host in the GSM block to be forwarded to the Bluetooth Host controller.

BRIEF SUMMARY OF THE INVENTION

A method and/or system for a fast power control mechanism for Bluetooth devices, substantially as shown in and/or described in connection with at least one of the figures, as set forth more completely in the claims.

DETAILED DESCRIPTION OF THE INVENTION

Certain embodiments of the invention may be found in a method and system for a fast power control mechanism for Bluetooth devices. Exemplary aspects of the method and system for a fast power control mechanism for Bluetooth devices may comprise performing using one or more processors and/or circuits in a second Bluetooth device, receiving from a first Bluetooth device, a request for a transmit power adjustment for one or more operating modes. A step size may be received for the transmit power adjustment via the received request. The transmit power adjustment may occur as a function of the step size. A feedback message may be sent to the first Bluetooth device, where the feedback message may indicate a status of the adjustment. The transmit power adjustment may be requested via a Link Management Protocol (LMP) message. One or more operating modes may comprise a Bluetooth Basic Rate (BR) mode, and/or a Bluetooth Enhanced Data Rate (EDR) mode. The received step size may be encoded in one or more bits of a reserved byte in the received request, and may be encoded utilizing 4 bits. It may be determined whether the first Bluetooth device is operable to utilize fast power control, and then an increase power message and/or the step size corresponding to the increase power message may be generated and/or received. It may be determined whether the first Bluetooth device is operable to utilize fast power control, and then a decrease power message and/or the step size corresponding to the decrease power message may be generated and/or received.

FIG. 1Ais a diagram illustrating an exemplary communications system utilizing Bluetooth, in accordance with an embodiment of the invention. Referring toFIG. 1A, there is shown a GSM handset150, a GSM base station152and Bluetooth headphones154. There is also shown a GSM wireless connection and a Bluetooth wireless connection.

The GSM handset150may comprise suitable logic, circuitry, interfaces and/or code that may be operable to wirelessly communicate data, including but not limited to voice. The GSM base station152may comprise suitable logic, circuitry, interfaces and/or code that may be operable to wirelessly communicate data, including but not limited to voice. The Bluetooth headphones154may comprise suitable logic, circuitry, interfaces, and/or code that may be operable to wirelessly communicate data, including but not limited to voice.

Many modern mobile devices may comprise Bluetooth functionality and/or possess the capability to utilize Bluetooth via a plug-in adapter. For example, Global System for Mobile Communications (GSM) handsets may comprise Bluetooth blocks to connect to a large variety of peripheral devices. InFIG. 1A, an exemplary GSM headset150may be operable to utilize a Bluetooth wireless connection to connect and communicate with the Bluetooth headphones154.

In addition to its core telephone functionality, the GSM handset150may comprise further functional blocks and/or chipsets to provide additional functionality. For example, the GSM handset150may comprise an audio decoder block that may efficiently decode a number of music formats. In order for the user of the GSM handset150to listen to audio decoded by the audio block on the Bluetooth headphones154, the GSM handset150may forward audio data from the audio block over its Bluetooth stack to the Bluetooth headphones154.

When the channel conditions for a Bluetooth wireless connection, for example between GSM handset150and Bluetooth headphones154may change, it may be desirable to adjust the data rates. In some instances, in particular if the channel conditions may not change very quickly, it may be desirable to use a same transmission power increase/decrease step size for all power changes. In these instances, because the step size may be fixed, no step size information need be fed back from the receiver to the transmitter. In instances where the data rates may need to be adjusted rapidly, it may be more efficient to feedback a variable step size for the transmission power control, so that the channel variations may be tracked closely.

FIG. 1Bis a block diagram illustrating an exemplary GSM handset with multiple Bluetooth hosts, in accordance with an embodiment of the invention. Referring toFIG. 1B, there is shown a GSM handset160, comprising a processor162, system memory168, a GSM block166, a multimedia block164, a Bluetooth host controller170, a GSM antenna174and a Bluetooth antenna172. The GSM block166may comprise a GSM core functionality block176and a GSM Bluetooth Host178. The multimedia block164may comprise a multimedia core functionality block180and a multimedia Bluetooth host182. There is also shown a GSM-processor interface190, a multimedia (MM)-processor interface192, a memory interface198, a Bluetooth (BT) interface200, and host controller interface (HCI) transport1194and HCI transport2196. The processor162may be a main processor or a baseband processor, for example.

The GSM handset160may comprise suitable logic, circuitry, interfaces and/or code that may be operable to wirelessly communicate data, including but not limited to voice. In one embodiment of the invention, the GSM block166, the system memory168, the multimedia block164, processor162, Bluetooth host controller170, the GSM antenna174and the Bluetooth antenna172may be functional blocks of a single chipset.

The processor162may comprise suitable logic, circuitry, interfaces and/or code that may be operable to control the GSM handset160, for example by utilizing system memory168via the memory interface198. The processor162may control the high-level functionality of the GSM handset160, for example, the user interface, and access to the GSM block166and the multimedia block164. Access to the GSM block166and the multimedia block164may occur via the GSM-processor interface190and the MM-processor interface192, respectively. In another embodiment of the invention, the functional blocks may each be a chip or some functional blocks may be combined into a chip.

The system memory168may comprise suitable logic, circuitry, interfaces and/or code that may be operable to store and retrieve data sent to and from the processor162via the memory interface198.

The GSM block166may comprise suitable logic, circuitry, interfaces and/or code that may be operable to control and operate a GSM radio interface, which may comprise generating radio-frequency signal for transmission via antenna174, and/or GSM core functionality block176, and/or a GSM Bluetooth host178. The processor162may access to the GSM block166and the multimedia block164may occur via the GSM-processor interface190and the MM-processor interface192, respectively. The GSM block166may provide the core mobile telephone functionality of the GSM handset160in the GSM core functionality block176. The GSM block166may also be communicatively coupled to the GSM antenna174. In addition, the GSM block166may comprise a GSM Bluetooth host178that may be used, for example, to connect to peripheral devices like headsets.

The GSM core functionality block176may comprise suitable logic, circuitry, interfaces and/or code that may be operable to generate, and process GSM signals.

The GSM Bluetooth Host178may comprise suitable logic, circuitry, interfaces and/or code that may be operable to generate and process signals related to the control and provide date with regard to Bluetooth functionality. The GSM Bluetooth host178in the GSM block166may also communicate directly with the Bluetooth host controller170via the HCI transport1.

The multimedia block164may comprise suitable logic, circuitry, interfaces and/or code that may be operable to process multimedia signals and access the GSM block166, the Bluetooth host controller170, and the processor162, via the MM-processor interface192, HCI transport2196, and the BT interface200, respectively. The multimedia block164may provide, for example, audio and video decoding for the GSM handset160. The multimedia block164may comprise a multimedia Bluetooth host182that may communicate directly with the Bluetooth host controller170via the HCI transport2196and the GSM Bluetooth host178via the Bluetooth interface200.

The multimedia core functionality block180may comprise suitable logic, circuitry, interfaces and/or code that may be operable to generate and process multimedia signals.

The multimedia Bluetooth host182may comprise suitable logic, circuitry, interfaces and/or code that may be operable to generate and process signals related to the Bluetooth functionality of the GSM handset160. The multimedia Bluetooth host182may interface the GSM Bluetooth host178via the BT interface200, and the Bluetooth host controller170via the HCI transport2196.

The Bluetooth host controller170may comprise suitable logic, circuitry, interfaces and/or code that may be operable to generate, receive and/or process a radio portion of the Bluetooth radio of the GSM handset160, and may be communicatively coupled to a Bluetooth antenna172.

The GSM antenna174may comprise suitable logic, circuitry, interfaces and/or code that may be operable to transmit and receive radio frequency signals that might be suitable for GSM communication. The GSM antenna174may be communicatively coupled to the GSM Chipset166.

The Bluetooth antenna172may comprise suitable logic, circuitry, interfaces and/or code that may be operable to transmit and receive radio frequency signals that might be suitable for Bluetooth communications. The Bluetooth antenna172may be communicatively coupled to the Bluetooth host controller172.

In operation, the processor162may control the overall functionality of the GSM handset160. For example, the processor162may process signals and information from the GMS chipset166and/or the multimedia chips set164via the GSM-processor interface190and the MM-processor interface192, respectively. In instances of Bluetooth communication, the multimedia chipset164and the GSM chipset166may transfer and suitably process data generated or controlled by the processor162via the HCI transport1194and the HCI transport2196, respectively.

When the channel conditions for a Bluetooth wireless connection, for example between GSM handset150and Bluetooth headphones154may change, it may be desirable to adjust the Bluetooth data rates in the GSM handset160. In particular, it may be desirable to adjust the data rates via the Bluetooth host controller170to adapt to the changing channel conditions. In some instances, in particular if the channel conditions may not change very quickly, it may be desirable to use a same transmission power increase/decrease step size for all power changes. In these instances, because the step size may be fixed, no step size information may have to be fed back from a receiver, for example a receiver in the GSM handset150or the Bluetooth headphones154, to the transmitter, for example a receiver in the GSM handset150or the Bluetooth headphones154. In instances where the data rates may need to be adjusted rapidly, it may be more efficient to feed back a variable step size for the transmission power control, so that the channel variations may be tracked closely.

WhileFIG. 1Bdepicts an exemplary GSM handset160, it may be envisaged that the wireless system inFIG. 1Bmay comprise any number of functional block combinations with multiple Bluetooth hosts. For example, an IEEE 802.11 WLAN block, a CDMA block or a WIMAX block may replace the GSM block166and a video block, an FM radio block, a keyboard controller block or a photo camera block may replace the multimedia block164. These functional blocks may or may not be comprised within a single chip.

FIG. 2illustrates exemplary communication between communicating Bluetooth devices via a Link Management Protocol, in accordance with an embodiment of the invention. Referring toFIG. 2, there is shown a device A202, and a device B204. The device A202and device B204may comprise suitable logic, circuitry, interfaces, and/or code that may be operable to communicate with other Bluetooth devices via radio-interface interface. The device A202and device B204may be compliant with Bluetooth 2.1, for example, which may be backwards compatible with Bluetooth 1.2 devices.

Power control may be required for Bluetooth Class 1 devices in the Bluetooth 2.1+Enhanced Data Rate (EDR) specification. Power control may be used for limiting the transmitted power in accordance with transmit conditions between device A202and device B204. Power step sizes to increment or decrement transmit power at device A202and/or device B204may typically range from 2 dB to 8 dB. In a radio connection between Bluetooth devices, the output transmit power may not exceed the maximum output power of the Bluetooth power class 2 for transmitting packets, when a receiving device does not support the necessary messaging for sending power control messages. Bluetooth devices may not exceed the maximum allowed transmit power levels set by controlling regulatory bodies. The maximum allowed transmit power level may depend upon the modulation mode. For example, in transmission206, the device A202may transmit a Link Management Protocol (LMP) message206to the device B204, which may request an increase in transmission power from the device B204. Such a message may be referred to as a LMP increase power request (LMP_incr_power_req) message.

In instances when the device B204, which is already set to operate at maximum transmission power, receives the LMP_incr_power_req, the device B204may send a message208, which indicates that the device B204may already be transmitting at maximum transmission power. The message208may be referred to as a LMP maximum power (LMP_max_power) message, for example. In this instance, the device A202may request a power increase again from device B204after having requested a power decrease by a LMP decrease power request (LMP_decr_power_req) message, at least once.

The device A202may, for example, send a request210to decrease transmission power to device B204, when the device B204may already have reached minimum transmission power. The message210requesting a decrease in transmission power may be referred to as LMP_decr_power_req. When the transmission power is at a minimum at the device B204, a message212indicating minimum transmission power may be returned to device A202. This message212may be referred to as a LMP minimum transmit power (LMP_min_power) message. In instances when the device B204may transmit at minimum power, the device A202may request a power decrease utilizing the LMP_decr_power_req message after having requested a power increase using the LMP_incr_power_req message at least once.

In accordance with an embodiment of the invention, a Bluetooth device may comprise five power control steps: for example, 0-4. In some instances, a Bluetooth device may be able to use a reduced set of power steps, based on the modulation employed, for example. In accordance with various embodiments of the invention, power steps 0-4 may be used for Gaussian Frequency-Shift Keying (GFSK), and power steps 0-3 may be used for Phase Shift Keying (PSK). In these instances, and in accordance with various embodiments of the invention, a maximum power reached message LMP_max_power, for example message210, or a minimum power reached message LMP_min_power, for example message212, may be returned as a function of the modulation and/or logical transport parameters.

Thus, a Bluetooth device, for example the device A202or the device B204, may have different maximum transmitting (TX) power levels for different modulation modes. The modulation modes may comprise, for example, Bluetooth Basic Rate (BR) and/or Bluetooth Enhanced Date Rate (EDR). A Bluetooth device may have the ability to control its transmission power independently for BR and EDR modulation schemes. A Bluetooth device's power class classification may be separated into BR and EDR power levels, in accordance with various embodiments of the invention, and as described above.

FIG. 2Bis an illustration of an exemplary LMP protocol data unit with a short opCode, in accordance with various embodiments of the invention. Referring toFIG. 2B, there is shown a payload220, and operations code (opCode)222, and a Transaction Identification (TID)224. The payload220may comprise a Link Management Protocol message, for example LMP_incr_power_req, LMP_decr_power_req, LMP_min_power, and LMP_max_power. The messages in the payload220may be structured as described inFIG. 2andFIGS. 3-5, for example. The payload220may comprise any LMP message, however, and is not limited to the ones listed above. The opCode222may comprise a code that may indicate the type of message that may be transmitted in the payload. The opCode may be, for example, a 7-bit field. The TID224may be used, for example, to identify the message, and may be desirable to avoid duplicate messages.

FIG. 2Cis an illustration of an exemplary LMP protocol data unit with a long opCode, in accordance with various embodiments of the invention. Referring toFIG. 2C, there is shown a payload230, and operations code (opCode)232, and a Transaction Identification (TID)234. The payload230may comprise a Link Management Protocol message, for example LMP_incr_power_req or LMP_decr_power req. The messages in the payload230may be structured as described inFIG. 2andFIGS. 3-5, for example. The payload230may comprise any LMP message, however, and is not limited to the ones listed above. The opCode232may comprise a code that may indicate the type of message that may be transmitted in the payload. The opCode may be, for example, a 15-bit field. The TID234may be used, for example, to identify the message, and may be desirable to avoid duplicate messages.

FIG. 3illustrates exemplary communication between communicating Bluetooth devices via a Link Management Protocol, in accordance with an embodiment of the invention. Referring toFIG. 3, there is shown a device A302, and a device B304.

The device A302and device B304may comprise suitable logic, circuitry, interfaces, and/or code that may be operable to communicate with other Bluetooth devices via radio-interface interface. The devices A302and device B304may be compliant with Bluetooth 2.1, for example, which may be backwards compatible with Bluetooth 1.2 devices.

The request messages to increase or decrease transmission power, LMP_incr_power_req and LMP_decr_power_req, may comprise a one-byte reserved field, in accordance with Bluetooth standard 1.2, for example. LMP messages may be carried in the payload220or payload230, as illustrated inFIG. 2BorFIG. 2C, respectively. In accordance with an embodiment of the invention, the one-byte reserved field in LMP_incr_power_req306and LMP_decr_power_req310may be utilized for power control. For a power increase message, LMP_incr_power_req306, bit0-bit3of the reserved one-byte field may be used to represent a base rate transmit power adjustment, BR_TX_power_adjustment, and bit4-bit7of the reserved one-byte field may represent an Enhanced Data Rate transmit power adjustment, EDR_TX_power_adjustment. Similarly, for a power decrease message, LMP_decr_power_req310, bit0-bit3may represent BR_TX_power_adjustment and bit4-bit7may represent EDR_TX_power_adjustment. For the BR_TX_power_adjustment, the power adjustment may occur in 2 dB steps, for example. The range may depend on the LMP message, for example.

In accordance with various embodiments of the invention, LMP_incr_power_req306message may comprise a range for the 4 bits of BR_TX_power_adjustment or EDR_TX_power_adjustment of 0-28 dB, in 2 dB steps, and e.g. 0xF (all ones) may indicate to go to the maximum transmission power. Thus, an LMP_incr_power_req306message may request a power increase, and indicate a desired step size. Similarly, a LMP_decr_power_req message310, for example, may use the 4-bit BR_TX_power_adjustment or EDR_TX_power_adjustment field to denote a step size 0-30 dB, in 2 dB steps. In accordance with various embodiments of the invention, the step size shall not be limited to 2 dB, and the number of bits used for a BR_TX_power_adjustment field, or EDR_TX_power_adjustment field shall not be limited to 4 bits.

In another embodiment of the invention, in instances when EDR may not be supported, bit4-bit7of the reserved byte may be set to zero, where zero may represent a zero step size, for example. When a Bluetooth link is not in EDR mode (for example, when a LMP_packet_table_type message may set the link into BR only mode) bit4-bit7may be set to zero, for example. Furthermore, if both fields BR_TX_power_adjustment field and EDR_TX_power_adjustment in the reserved byte are set to zero, for example, an error code “invalid LMP parameters” may be returned. If a requested adjustment field (for BR or EDR) may be set to zero, this may indicate that transmit power for the corresponding modulation scheme should not be lowered or increased from the current setting. Upon baseband acknowledgement (ACK), when it occurs, a receiving device may apply a desired power step within, for example, 80 time slots.

FIG. 4illustrates an exemplary communication between communicating Bluetooth devices via a Link Management Protocol, in accordance with an embodiment of the invention. Referring toFIG. 4, there is shown a device A402, and a device B404. The device A402and device B404may comprise suitable logic, circuitry, interfaces, and/or code that may be operable to communicate with other Bluetooth devices via radio-interface interface. The devices A402and device B404may be compliant with Bluetooth 2.1, for example, which may be backwards compatible with Bluetooth 1.2 devices.

In another embodiment of the invention, new Link Management Protocol (LMP) messages may be utilized to increase or decrease the power resolution. For example, an LMP increase power resolution LMP_incr_power_res606and a LMP decrease power resolution LMP_decr_power_res410may utilized. For the LMP_incr_power_res406, bit0-bit3may represent BR_TX_power_adjustment, which may denote that BR transmit power may increase in 2 dBm steps (0-30), for example. For LMP_incr_power_res406, bit4-bit7may represent EDR_TX_power_adjustment, which may denote that EDR transmit power may increase in 2 dBm steps (0-30 dB), for example. For the LMP_decr_power_res410, bit0-bit3may represent BR_TX_power_adjustment, which may denote that BR TX power may decrease in 2 dBm steps (0-30 dB), for example. For the LMP_decr_power_res410, bit4-bit7may represent EDR_TX_power_adjustment, which may denote that EDR transmit power may decrease in 2 dBm steps (0-30 dB).

In accordance with various embodiments of the invention, in instances were EDR may not be supported, EDR_TX_power_adjustment may be set to zero, which may indicate no change in transmission power. In instances where the achievable transmit power adjustment due to a LMP_incr_power_res406message or LMP_decr_power_res410message may be less than the requested value for a given modulation method, this may indicate that the maximum or the minimum transmit power has been reached. In these instances, no further non-zero (requiring a change) power increase or decrease LMP messages may be sent for the corresponding data rate (BR or EDR) until a request in the reverse direction of power change may have been sent at least once. In instances when the actual transmit power adjustment in the LMP_incr_power_res406or LMP_decr_power_res410may be similar to the requested value for the respective modulation method. In these instances, an inference about whether or not maximum or minimum transmit power may have been reached may not be made.

In another embodiment of the invention, one or more new LMP message feature bit(s) may be utilized, for example, for fast power control (FPC), which may be used to indicate that a device may be capable of fast power control. Once both Bluetooth devices, device A402and device B404are operable to support FPC, the LMP_incr_power_req306, LMP_incr_power_res406, LMP_decr_power_req310, and LMP_dec_power_res410messages may be exchanged. In this regard, no new Host Controller (HCI) commands or events may be required. Thus, no host involvement may be necessary for this feature.

Various embodiments of the invention may enable the Bluetooth transmitting device to provide information about its current transmit power level for BR and EDR respectively. Accordingly, various embodiments of the invention may provide a closed loop power control scheme to reach the desired power level faster. Various embodiments of the invention may enable interpretation of existing LMP power control commands.

FIG. 5is a flow chart illustrating exemplary communication between communicating Bluetooth devices via a Link Management Protocol, in accordance with an embodiment of the invention.

In step504, for example based on channel conditions, a power control algorithm may determine when a power increase message or a power decrease message may be sent. In steps506and508, a request message to increase or decrease transmission power, LMP_incr_power_req508or LMP_decr_power_req506, may comprise a one-byte reserved field, in accordance with Bluetooth standard 1.2, for example. LMP messages may be carried in the payload220or payload230, as illustrated inFIG. 2BorFIG. 2C, respectively. In accordance with an embodiment of the invention, the one-byte reserved field in LMP_incr_power_req508and LMP_decr_power_req506may be utilized for power control. For a power increase message, LMP_incr_power_req508, bit0-bit3of the reserved one-byte field may be used to represent a base rate transmit power adjustment, BR_TX_power_adjustment, and bit4-bit7of the reserved one-byte field may represent an Enhanced Data Rate transmit power adjustment, EDR_TX_power_adjustment. Similarly, for a power decrease message, LMP_decr_power_req506, bit0-bit3may represent BR_TX_power_adjustment and bit4-bit7may represent EDR_TX_power_adjustment. For the BR_TX_power_adjustment, the power adjustment may occur in 2 dB steps, for example. The range may depend on the LMP message, for example.

In accordance with various embodiments of the invention, the LMP_incr_power_req508message may comprise a range for the 4 bits of BR_TX_power_adjustment or EDR_TX_power_adjustment of 0-28 dB, in 2 dB steps, and e.g. 0xF (all ones) may indicate to go to the maximum transmission power. Thus, an LMP_incr_power_req508message may request a power increase, and indicate a desired step size. Similarly, a LMP_decr_power_req message506, for example, may use the 4-bit BR_TX_power_adjustment or EDR_TX_power_adjustment field to denote a step size 0-30 dB, in 2 dB steps. In accordance with various embodiments of the invention, the step size may not be limited to 2 dB, and the number of bits used for a BR_TX_power_adjustment field, or EDR_TX_power_adjustment field may not be limited to 4 bits.

In another embodiment of the invention, in instances when EDR may not be supported, bit4-bit7of the reserved byte may be set to zero, where zero may represent a zero step size, for example. When a Bluetooth link is not in EDR mode (for example, when a LMP_packet_table_type message may set the link into BR only mode) bit4-bit7may be set to zero, for example. Furthermore, when both fields BR_TX_power_adjustment field and EDR_TX_power_adjustment in the reserved byte are set to zero, for example, an error code “invalid LMP parameters” may be returned. In instances when a requested adjustment field (for BR or EDR) may be set to zero, this may indicate that transmit power for the corresponding modulation scheme should not be lowered or increased from the current setting. Upon occurrence of a baseband acknowledgement (ACK), a receiving device may apply a desired power step within, for example, 80 time slots.

In step512, when a power increase is requested in step512and when the maximum transmission power may have been reached, a message516may be returned, indicating that the maximum transmission power has been reached. Similarly, when a power decrease is requested in step510, and when the minimum transmission power may have been reached, a message514may be returned, indicating that the minimum transmission power has been reached.

In accordance with an embodiment of the invention, a method and system for a fast power control mechanism for Bluetooth devices may comprise performing using one or more processors and/or circuits in a second Bluetooth device, for example Headphones154receiving from a first Bluetooth device, for example mobile phone150, a request for a transmit power adjustment for one or more operating modes. As described with respect toFIG. 3, a step size, for example EDR_TX_power_adjustment, may be received for the transmit power adjustment via the received request, for example LMP incr_power_req. The transmit power adjustment may be adjusted as a function of the step size. A feedback message, for example LMP_max_power, may be sent to the first Bluetooth device, wherein the feedback message may indicate a status of the adjusting, as described with respect toFIGS. 3-5. The transmit power adjustment may be requested via a Link Management Protocol (LMP) message, for example LMP_decr_power_req. One or more operating modes may comprise a Bluetooth Basic Rate (BR) mode, and/or a Bluetooth Enhanced Data Rate (EDR) mode. The received step size may be encoded in one or more bits of a reserved byte in the received request, as described with respect toFIGS. 3-5, and may be encoded utilizing 4 bits, for example. As described with respect toFIG. 3andFIG. 4, it may be determined whether the first Bluetooth device, for example mobile phone150, is operable to utilize fast power control, and then an increase power message LMP_incr_power_req and/or the step size, for example, BR_TX_power_adjustment corresponding to the increase power message may be generated and/or received. It may be determined whether the first Bluetooth device is operable to utilize fast power control, and then a decrease power message, for example LMP_decr_power_req and/or the step size, for example EDR_TX_power_adjustment, corresponding to the decrease power message may be generated and/or received.

Another embodiment of the invention may provide a machine-readable and/or computer-readable storage and/or medium, having stored thereon, a machine code and/or a computer program having at least one code section executable by a machine and/or a computer, thereby causing the machine and/or computer to perform the steps as described herein for a method and system for a fast power control mechanism for Bluetooth devices.