Patent Description:
Embodiments of the present invention generally relate to the field of wireless communications. More specifically, embodiments of the present invention relate to systems and methods for controlling wireless devices to efficiently manage power when communicating using multi-band communication in a wireless network.

Modern electronic devices typically send and receive data with other electronic devices wirelessly using Wi-Fi, and many of these devices are "dual band" devices that include at least two wireless transceivers capable of operating in different frequency bands e.g., <NUM> and <NUM>. In most cases, a wireless device will communicate over only a single band at a time. For example, older and low-power devices e.g., battery powered devices, often operate on the <NUM> band. Newer devices and devices that require greater bandwidth often operate on the <NUM> band.

However, in some cases, the use of a single band may not satisfy the bandwidth needs of certain devices. Therefore, some developing approaches to wireless communication increase communication bandwidth by operating on multiple bands concurrently, and can control which wireless device or devices can use the multiple bands, for example, based on current network traffic. What is needed is an approach to wireless power management that can utilize multiple bands concurrently to manage the power of wireless devices in a wireless network. <CIT> discloses an apparatus for implementing power control for a radio device that has multiple radio transceivers operating in different bands, including sub-bands of a single frequency band. <CIT> discloses a method and apparatus of switching a band in a wireless local access network, which includes transmitting a multi-band switch request message to request switching from a first frequency band to a second frequency band. <CIT> discloses a wireless station for operation in a wireless network that communicates over a first band and a second band, where operation of the first band includes operation of a first set of band-specific medium access control processing and physical-layer circuitry of the STA, and wherein operation of the second band includes operation of a second set of band-specific medium access control processing and physical-layer circuitry of the STA.

A method according to the present invention is defined in the independent claim. The dependent claims define preferred embodiments thereof.

According to one embodiment, which is an embodiment of the invention, a method of managing a power state of a wireless station (STA) for cooperative multi-band operation between the STA and a wireless access point (AP) for a wireless network is disclosed. The method includes receiving a frame transmitted from the AP to the STA over the first band, said frame comprising a Frame Control field comprising a More Data, in the following also referred to as MD, field indicating a buffer status of the second band, and updating a power management mode of the STA for the second band according to the buffer status of the second band received from the STA over the second band.

Preferably, the frame comprises a CAS control subfield including a service period status subfield and a power management mode, and where the updating a power management mode of the STA for the second band includes updating the service period status of the STA for the second band according to the service period status subfield of the CAS control subfield.

Preferably, the first band and the second band respectively include at least one of: a <NUM> band; a <NUM> band; and a <NUM> band.

Preferably, said updating a power management mode of the STA for the second wireless band is performed according to a power management mode of a CAS control subfield of the frame.

Preferably, the frame is a QoS Null frame from the STA to the AP using a first band, where the STA and the AP are in wireless communication using the first band and a second band, and where the QoS Null frame triggers a service period (SP) for the first band and the second band, updating a power management mode of the STA for the second band according to a first EOSP subfield of the QoS Null frame, where the second band is identified by a band information subfield of the QoS Null frame, and updating a power management mode of the STA for the first band according to a second EOSP subfield of the QoS Null frame.

Preferably, the first EOSP subfield and the band information subfield are included in an A-Control field of the QoS Null frame.

Preferably, the second EOSP subfield is included in a QoS Control field of the QoS Null frame.

Preferably, the method includes receiving a QoS Data frame from the AP at the STA using the second band, updating a power management mode of the STA for the second band according to a first EOSP subfield of the QoS Data frame, and updating a power management mode of the STA for the first band according to a second EOSP subfield of the QoS Data frame, where the first band is indicated by a band information subfield of the QoS Data frame.

Preferably, the second EOSP subfield and the band information subfield are included in an A-Control field of the QoS Data frame, and where the first EOSP subfield is included in a QoS Control field of the QoS Data frame.

Preferably, the QoS Data frame includes a first More Data (MD) subfield indicating additional data is buffered on the first band, and a second MD subfield indicating additional data is buffered on the second band.

Preferably, the power management mode of the STA is updated for the first band where the STA is in an awake mode on the first band when more data is available on the first band, and the power management mode of the STA is updated for the first band where the STA is in a doze mode on the first band when no more data is available on the first band.

According to another embodiment, which is helpful for understanding the invention, a dual-band device for performing cooperative multi-band operation with a wireless access point (AP) for a wireless network is disclosed. The device includes a first transceiver configured to communicate over a first wireless band, a second transceiver configured to communicate over a second wireless band, where the first transceiver and the second transceiver are operable to communicate simultaneously, a cooperative management unit configured to exchange data with the first transceiver and the second transceiver for managing simultaneous communication of the first transceiver and the second transceiver, and a processor operable to cause to be transmitted a frame from the device to the AP over the first wireless band, where the device and the AP are in wireless communication using the first wireless band and the wireless second wireless band. The frame includes a multi-band control subfield including a band indication of the second wireless band, and a Command and Status (CAS) control subfield including a power management mode for the second wireless band. The processor is further operable to update a power management mode of the device for the second wireless band according to the power management mode of the CAS control subfield.

Preferably, the CAS control subfield further includes a service period status subfield, and where the update a power management mode of the device for the second wireless band includes updating a service period status of the device for the second wireless band according to the service period status subfield of the CAS control subfield.

Preferably, the first wireless band and the second wireless band individually include at least one of a <NUM> band, a <NUM> band, and a <NUM> band.

Preferably, the processor is further operable to access a traffic indication map (TIM) for the first wireless band and the second wireless band based on a respective traffic type associated with the first wireless band and the second wireless band.

Preferably, the processor is further operable to determine a buffer status of the first wireless band and the second wireless band according to the TIM.

Preferably, the multi-band control subfield includes a control ID subfield has a value of <NUM> to indicate that the CAS control subfield is applied on the second wireless band indicated by the band information.

The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention:.

Reference will now be made in detail to several embodiments. While the subject matter will be described in conjunction with the alternative embodiments, it will be understood that they are not intended to limit the claimed subject matter to these embodiments.

Furthermore, in the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the claimed subject matter. However, it will be recognized by one skilled in the art that embodiments may be practiced without these specific details or with equivalents thereof. In other instances, well-known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure aspects and features of the subject matter.

Portions of the detailed description that follows are presented and discussed in terms of a method. Although steps and sequencing thereof are disclosed in a figure herein (e.g., <FIG> and <FIG>) describing the operations of this method, such steps and sequencing are exemplary. Embodiments are well suited to performing various other steps or variations of the steps recited in the flowchart of the figure herein, and in a sequence other than that depicted and described herein.

Some portions of the detailed description are presented in terms of procedures, steps, logic blocks, processing, and other symbolic representations of operations on data bits that can be performed on computer memory. These descriptions and representations are the means used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. A procedure, computer-executed step, logic block, process, etc., is here, and generally, conceived to be a self-consistent sequence of steps or instructions leading to a desired result. The steps are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated in a computer system.

Unless specifically stated otherwise as apparent from the following discussions, it is appreciated that throughout, discussions utilizing terms such as "accessing," "writing," "including," "storing," "transmitting," "associating," "identifying," "encoding," or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices.

Embodiments of the present invention provide a method and apparatus for simultaneous transmission and reception of data wirelessly using different wireless bands. The multi-link operations described herein can provide higher network throughput and improved network flexibility compared to traditional techniques to wireless communication. Power management operations are performed by devices communicating using multiple bands simultaneously where a first wireless band can be used to send and receive power management control frames for use on a second wireless band. In this way, a device that is in a sleep or dose power management state on a first band can be instructed to enter a awake power management state on the first band based on a communication received over a second band that is currently active and receiving data. Embodiments of the present invention enable power to be conserved when a band is not currently being used, or when there is no more data available (buffered) for a specific band.

As used herein, the term "EHT" may refer to a recent generation of wireless communication (Wi-Fi) known as Extremely High Throughput (EHT) and is defined according to the IEEE <NUM>. 11be standards. The term station (STA) may refer to an electronic device capable of sending and receiving data over Wi-Fi that is not operating as an access point (AP).

With regard to <FIG>, an exemplary wireless communication system <NUM> including a multi-band cooperative AP <NUM> and a multi-band cooperative STA <NUM> are depicted according to embodiments of the present invention. The multi-band cooperative AP <NUM> includes a <NUM> transceiver <NUM> and a <NUM> transceiver <NUM>. Other types of transceivers that operate on different bands, such as <NUM> and above, can also be used by the multi-band cooperative AP <NUM> according to embodiments of the present invention. The transceivers <NUM> and <NUM> of AP <NUM> exchange data and information with cooperative management unit <NUM> that coordinates information sent and/or received by transceivers <NUM> and <NUM>.

The multi-band cooperative ST <NUM> includes a <NUM> transceiver <NUM> and a <NUM> transceiver <NUM>. Other types of transceivers that operate on different bands, such as <NUM> and above, can also be used by the multi-band cooperative STA <NUM> according to some embodiments of the present invention. The transceivers <NUM> and <NUM> of STA <NUM> exchange data and information with cooperative management unit <NUM> that coordinates information sent and received by transceivers <NUM> and <NUM> using <NUM> band wireless communication and <NUM> band wireless communication, respectively.

The multi-band cooperative AP <NUM> and the multi-band cooperative STA <NUM> have simultaneous transmission and reception capability for communicating using different wireless bands. The transmitters operating on the different bands can perform independent clear channel assessments (CCAs) using joint or intendent transmissions. Moreover, full duplex communication can be enabled by independent multi-band operation using FDD mode.

The STA <NUM> can access channels in multiple bands independently. For example, after receiving an enhanced distributed channel access (EDCA) transmission opportunity (TXOP) frame, the STA <NUM> can begin transmitting frames over the respective band during the window of time provided in the EDCA TXOP frame. When the STA <NUM> receives EDCA TXOP frames in multiple bands simultaneously, the STA <NUM> can transmit frames using multiple bands simultaneously during the provided window of time.

The STA <NUM> transmitting frames using multiple bands simultaneously can mitigate delay and improve peak throughput of the STA <NUM>. However, in some cases, transmitting frames using multiple bands simultaneously can degrade the performance of the basic service set (BSS) comprising the STA <NUM>. For example, the performance of the BSS can be degraded when the STA <NUM> operating on multiple bands simultaneously uses a substantial amount of the bandwidth available to the BSS due to the increased traffic. Therefore, the AP <NUM> can control which STAs are granted multi-band channel access, and the access can be terminated by the AP at any time, for example, based on changing network conditions or requirements.

Depending on certain conditions, such as traffic load, a non-AP STA may use fewer than all supported/available links in order to reduce energy consumption. Moreover, a non-AP STA may apply an independent power management for each link, and the AP can provide buffer status information for each links. Depending the Quality of Service (QoS) policy of the Basic Service Set (BSS), an AP may allocate the traffic to different links based on traffic type, such as voice, video, data, etc. For example, frames belonging to a first Traffic Identifier (TID <NUM>) can be allocated to a first link, and frames belonging to a second Traffic Identifier (TID <NUM>) can be allocated to a second link. In this case, the AP may provide buffer status information for both links to the STA, where some data can only be sent on the first link, and other data can only be sent on the second link.

<FIG> depicts an exemplary multi-band wireless transmission diagram <NUM> between wireless communication devices using a <NUM> band <NUM> and a <NUM> band <NUM> according to embodiments of the present invention. A TXOP frame is received by an STA performing channel access operations in multiple bands independently. After obtaining the TXOP frame, the STA transmits frames over multiple bands. For example, when the STA obtains TXOPs in bands <NUM> and <NUM>, the STA can transmit frames in bands <NUM> and <NUM> simultaneously.

Instead of transmitting an individual ACK for every frame, multiple frames can be acknowledged together using a single Block Ack (BA) frame. A BA typically contains a bitmap size of <NUM>*<NUM> bits. These <NUM> bits indicate the fragment number of the frame to be acknowledged. Each bit of this bitmap represents the status (success/failure) of a frame. To perform cooperative multi-band operations, an AP and STA establish cooperative multi-band operations for sending frames <NUM> and <NUM> using the multiple bands. If the frames are under a block ack agreement, an ADDBA Request frame may be transmitted and includes multiple multi-band information elements for indicating the bands on which an STA can send frames of the TID as indicated in the ADDBA Request frame.

When an STA that is transmitting frames using one or more bands schedules a new frame transmission using a different band than the bands currently used by the STA, and the current frame is under a block ack agreement, the STA may use the same TID for the scheduled frame only if the reordering buffer for the TID of the current frame is available. Otherwise, the STA chooses a TID for the scheduled frame that is different than the TID of the current frame.

When the current frame is not under a block acknowledgement, the STA may choose the scheduled frame from the same TID with the ongoing frame only if the ongoing frame has no more retries (including a frame having the Ack Policy field set to No Ack) and the transmission end time of the scheduled frame is not earlier than the transmission end time of the current frame. Otherwise, the STA may choose the scheduled frame from a TID that is different than the TID of the current frame. Scheduling the frame from a TID that is different from the TID of the current frame simplifies the transmission protocol, but the performance of the cooperative multi-band operation may be reduced.

<FIG> depicts an exemplary multi-band wireless transmission diagram <NUM> between wireless communication devices for establishing cooperative multi-band operation according to embodiments of the present invention. When the current frame is not under a block ack agreement, an STA can transmit data frames Seq1 <NUM> and Seq2 <NUM> from TID1 on <NUM> band <NUM> and <NUM> band <NUM> simultaneously. If the data frame of Seq1 <NUM> transmitted on <NUM> band <NUM> fails, the STA retransmits the data frame of Seq1 <NUM>. The recipient STA delivers the data frame of Seq2 <NUM> to an upper layer and then delivers the retransmitted data frame of Seq1 <NUM> to an upper layer.

<FIG> depicts an exemplary multi-band wireless transmission diagram <NUM> between wireless communication devices for establishing cooperative multi-band operation using fragmented frames according to embodiments of the present invention. Scheduled frames <NUM> and <NUM> are transmitted on <NUM> band <NUM> and <NUM> band <NUM> simultaneously. When the current frame is a fragmented frame, the STA may choose the scheduled frames <NUM> and <NUM> from the remaining fragmented frames.

When a non-AP STA receives a Trigger frame from an AP in a first wireless band (e.g., <NUM>), the non-AP STA can calculate the path loss from the received signal strength index (RSSI) and the AP Tx Power of the Common Info field of the Trigger frame. The downlink (DL) path loss information is used for performing channel access and determining the rate selection of the frame transmitted from the non-AP STA to the AP in a second band. When the back-off timer for the channel access in the second band is expired, the non-AP STA does not initiate a frame transmission to the AP if the non-AP STA determines that the minimum receiver sensitivity on the AP is not met.

A non-AP STA can also change the operating mode of the second wireless band based on the DL path loss information. For example, the non-AP STA can reduce the Rx Channel Width and Rx Number of Spatial Streams (NSS) in the second band when the DL path loss increases. Alternatively, the non-AP STA can pause a transmission from the AP to the non-AP STA in the second wireless band by entering power save mode in the second wireless band.

A non-AP STA can change the Rx Channel Width and Rx NSS of the second wireless band by sending a frame in the first wireless band. The frame contains the Multi-band Control subfield including band information indicating the second wireless band, and the Control ID is set to "<NUM>" to indicate that the OM Control subfield is applied on the second wireless band (the wireless band indicated by the band information). The frame also contains the OM Control subfield representing modified operating parameters for the second wireless band. The AP that received the frame in the first band updates the Rx operating parameters in the second wireless band of the STA.

The non-AP STA can modify the Tx Channel Width and Tx NSS in the second wireless band by sending a frame in the first wireless band. The frame contains the Multi-band Control subfield including band information indicating the second band, and the Control ID is set to "<NUM>" to indicate that the OM Control subfield is applied on the second wireless band (the band indicated by the band information). The frame also include an OM Control subfield representing the modified Tx operating parameters for the second band. The AP that receives the frame in the first band updates the Tx operating parameters in the second band of the STA.

The non-AP STA can report the buffer status of the second band by sending a frame in the first wireless band. The frame includes the Multi-band Control subfield containing band information indicating the second wireless band. The Control ID is set to "<NUM>" to indicate that the buffer status report (BSR) subfield is applied to the second wireless band (the band indicated by the band information). The frame also includes the BSR Control subfield representing the buffer status of the second band. The AP that received the frame in the first wireless band updates the buffer status in the second wireless band of the STA.

A non-AP STA can report the available channels of the second wireless band by sending a frame in the first wireless band having a Multi-band Control subfield containing band information indicating the second wireless band. The Control ID is set to "<NUM>" to indicate that the Bandwidth Query Reports (BQR) subfield is applied to the second wireless band (the band indicated by the band information). The BQR Control subfield represents the available channel bitmap in the second band. If the network allocation vector (NAV) of the STA in the second wireless band indicates that the wireless channel is busy, all values of the available channel bitmap shall be set to "<NUM>" indicating that the channels are busy or unavailable. The AP that received the frame in the first wireless band updates the available channels of the second wireless band of the STA.

With regard to <FIG>, exemplary control fields <NUM> and <NUM> are used to indicate which A-Control field is applied to different bands for cooperative multi-band operation according to embodiments of the present invention. If the Control ID subfield in a Control subfield of an A-Control subfield is "<NUM>" (indicating Multi-band Control), then the Control Information subfield of the Control subfield contains the band information and the band ID for performing Multi-band Control.

The band information represented by Band ID <NUM> in a Multi-band Control subfield <NUM>, or by Operating Class <NUM> and Channel Number <NUM> in Multi-band Control subfield <NUM>, specify the band on which A-Control field transmitted in the same frame (e.g., a MAC Protocol Data Unit (MPDU)) is applied. The Band ID <NUM> can be set to <NUM> (TV white spaces), <NUM> (Sub-<NUM> excluding TV white spaces), <NUM> (<NUM>), <NUM> (<NUM>), <NUM> (<NUM> and <NUM>), <NUM> (<NUM>), <NUM> (UNII-<NUM>), <NUM> (UNII-2A), <NUM> (UNII-2B), <NUM> (UNII-2C), <NUM> (UNII-<NUM>), <NUM> (UNII-<NUM>), <NUM> (UNII-<NUM>), <NUM> (UNII-<NUM>), <NUM> (UNII-<NUM>), and <NUM> (Reserved) depending on the type of data to be transmitted. The Control ID <NUM> or <NUM> specifies which A-Control field is applied on the band that is specified in the band information (e.g., Band ID <NUM> in control field <NUM> or Operating Class <NUM> and Channel Number <NUM> in control field <NUM>).

<FIG> depict an exemplary Command and Status (CAS) control subfields <NUM> provided by a non-AP STA to an AP according to embodiments of the present invention. The AP that receives the frame in a first band updates the power management mode of the STA in a second band. Specifically, the non-AP STA pauses a transmission from the AP to the non-AP STA in the second band and sends a frame in the first band, where the frame contains a Multi-band Control subfield (e.g., Multi-band Control subfield <NUM> or <NUM>) having band information indicating the second band, and a Control ID set to "<NUM>" to indicate that the CAS subfield <NUM> is applied on the second band (the band indicated by the band information). The frame includes the CAS Control subfield <NUM> having a Power Management (PM) field <NUM> representing the power management mode of the second band of the STA.

<FIG> depict an exemplary CAS control subfields <NUM> provided by a non-AP STA to an AP according to embodiments of the present invention. The AP that receives the frame in a first band updates the power management mode of the STA in a second band. Specifically, the non-AP STA triggers a Service Period (SP) in the second band and sends a frame in the first band, where the frame contains a Multi-band Control subfield (e.g., Multi-band Control subfield <NUM> or <NUM>) having band information indicating the second band, and a Control ID set to "<NUM>" to indicate that the CAS subfield is applied on the second band (the band indicated by the band information). The frame includes the CAS Control subfield <NUM> having a PM field <NUM> representing the power management mode of the second band of the STA, and an EOSP field <NUM> representing the Unscheduled Automatic Power Save Delivery (U-APSD) Service Period status of the second band of the STA. The EOSP field for triggering a Service Period (SP) in the second band is set to "<NUM>".

With regard still to <FIG>, an AP that terminates a Service Period in the second band may send a frame using the first band including a Multi-band Control subfield (e.g., Multi-band Control subfield <NUM> or <NUM>) having band information indicating a second band, and a Control ID set to "<NUM>" to indicate that the CAS subfield <NUM> is applied on the second band (the band indicated by the band information). The frame includes the CAS Control subfield <NUM> having an EOSP field <NUM> representing the U-APSD Service Period status of the second band of the STA. The EOSP field for triggering a Service Period (SP) in the second band is set to "<NUM>". The non-AP STA that receives the frame in the first band updates the Service Period status of the STA in the second band.

Preferably, a PM field <NUM> carried in a Frame Control field can indicate the power management mode of the first band on which the frame is sent, and the PM field in the A-Control field can be used to indicate the power management mode of the second band (the band indicated by the band information in the A-Control field). Similarly, the EOSP field in a QoS Control field can be used to indicate the SP status of the first band on which the frame is sent, and the EOSP field in an A-Control field can indicate the SP status of the second band (the band indicated by the band information in the A-Control field).

With regard to <FIG>, an exemplary transmission timing diagram <NUM> depicts an AP and a non-AP STA operating using cooperative multi-band communication over a <NUM> band <NUM> and a <NUM> band <NUM> according to embodiments of the present invention. The STA transitions from an active mode used to transmit and receive data to a passive Power Saving (PS) mode to conserve power. QoS Null frames <NUM> and <NUM> are transmitted by the STA over the <NUM> band <NUM> to control the PM mode of the STA. QoS Null frame <NUM> sent over the <NUM> band <NUM> by the STA changes the power management mode in the <NUM> band <NUM> from the Active mode to the PS mode.

Specifically, as depicted in <FIG>, the QoS Null frame <NUM> includes an A-Control field setting the PM mode to <NUM> for the <NUM> band <NUM>, and a frame control field setting the PM mode to <NUM> for the <NUM> band <NUM>. The QoS Null frame <NUM> sent in the <NUM> band <NUM> by the STA changes the power management mode in the <NUM> band <NUM> from the PS mode to the Active mode and changes the power management mode in the <NUM> band <NUM> from the Active mode to the PS mode. Specifically, the QoS Null frame <NUM> includes an A-Control field setting the PM mode to <NUM> for the <NUM> band <NUM>, and a Frame Control field setting the PM mode to <NUM> for the <NUM> band <NUM>.

With regard to <FIG>, an exemplary transmission timing diagram <NUM> depicting an AP and a non-AP STA operating using cooperative multi-band communication over a <NUM> band <NUM> and a <NUM> band <NUM> to control the STA awake state according to embodiments of the present invention. QoS Null frame <NUM> is sent over the <NUM> band <NUM> by the STA and triggers the Service Periods in both the <NUM> band <NUM> and the <NUM> band <NUM>. QoS Data frame <NUM> sent over the <NUM> band <NUM> by the AP terminates the Service Periods in both the <NUM> band <NUM> and <NUM> band <NUM>.

Specifically, as depicted in <FIG>, QoS Null frame <NUM> includes an A-Control field having an EOSP field indicating that the STA should enter an awake state for the corresponding <NUM> band <NUM> indicated by the Multi-band subfield of the A-control field. The QoS Null frame <NUM> also includes a QoS control field having an EOSP field indicating that the STA should enter an awake state for the corresponding <NUM> band <NUM>. The QoS Data frame <NUM> includes a QoS control field having an EOSP field indicating that the STA should enter a doze state for the corresponding <NUM> band <NUM>. The QoS Data frame <NUM> also includes an A-Control field having an EOSP field indicating that the STA should enter a doze state for the corresponding <NUM> band <NUM> indicated by the Multi-band subfield of the A-control field.

According to embodiments of the present invention, an AP can assign an association ID (AID) to each STA associated with each link of the multi-link operation when frames of a specific traffic type can only be transmitted on an allocated link. A Traffic Indication Map (TIM) IE, such as a traffic indication virtual bitmap bit associated with an AID for each link, can be used to indicate the buffer status of the corresponding links.

Alternatively, instead of assigning AIDs for each STA associated with each link based on traffic type and stored in a TIM, as depicted in <FIG>, a More Data (MD) field <NUM> in a Frame Control field <NUM> corresponding to an individually addressed frame that is sent to the STA indicates the buffer status for the link on which the frame is sent according to embodiments of the present invention. According to some embodiments, the MAC header of the frame has a More Data field (one bit) indicating that there is more data to deliver for out of band signaling. The non-AP STA that received the frame in the first band may initiate the SP of the STA in the second band in order to receive the buffered data over the second band.

Specifically, the AP that provides the buffer status of the second band sends a frame over the first band including a Multi-band Control subfield (e.g., Multi-band Control subfield <NUM> or <NUM>) and a CAS Control subfield <NUM>. The band information in the Multi-band Control subfield indicates the second band, and the Control ID is set to "<NUM>" to indicate that the CAS subfield <NUM> is applied to the second band (the band indicated by the band information). More Data field <NUM> of the CAS subfield <NUM> indicates the buffer status in the second band of the AP. PM field <NUM> represents the power management mode of the second band of the STA, and EOSP field <NUM> represents the U-APSD Service Period status of the second band of the STA. In generally, when more data is available for out of band communication, the A-Control field sent over a first band will cause the STA to enter an awake state to send or receive the available data over a second band.

With regard to <FIG>, an exemplary transmission timing diagram <NUM> depicting an AP and non-AP STA operating using cooperative multi-band communication over a <NUM> band <NUM> and a <NUM> band <NUM> to control the STA awake state based on a More Data (MD) field is depicted according to embodiments of the present invention. A QoS Data frame <NUM> sent over the <NUM> by the AP indicates that there is no more buffered data for the STA in the <NUM> band <NUM>, and indicates that there is more buffered data for the STA in the <NUM> band <NUM>. Therefore, the STA moves to a power saving doze state for the <NUM> band <NUM> because there is no more buffered data in the <NUM> band <NUM>, and the STA moves to an awake state for the <NUM> band <NUM> because the STA was notified that there is more buffered data in the <NUM> band <NUM>.

Specifically, as depicted in <FIG>, QoS Null frame <NUM> includes a QoS Control field having an EOSP field indicating that the STA should enter an awake state for the corresponding <NUM> band <NUM>. The QoS Data frame <NUM> includes a Frame Control field having an EOSP field indicating that the STA should enter a doze state for the corresponding <NUM> band <NUM> because the MD field indicates that no more data is available (buffered) for the <NUM> band <NUM>. The QoS Data frame <NUM> also includes an A-Control field having a MD field indicating that more data is available in the <NUM> band. Therefore, the corresponding QoS Null frame <NUM> includes an EOSP field indicating that the STA should enter an awake state on the <NUM> band <NUM> because more data is available.

With regard to <FIG>, a flow chart of an exemplary sequence of computer-implemented steps <NUM> for managing a power state of a wireless station (STA) for cooperative multi-band operation between the STA and a wireless access point (AP) is depicted for a wireless network according to embodiments of the present invention.

At step <NUM>, as depicted in <FIG>, the STA and the AP are in wireless communication using a first band and a second band. A frame is transmitted from the STA to the AP over the first band. The frame includes a Multi-band control subfield having a band indication of the second band, and a CAS control subfield comprising a power management mode for the second band.

At step <NUM>, a power management mode of the STA is updated for the second band according to the power management mode of the CAS control subfield.

With regard to <FIG>, a flow chart of an exemplary sequence of computer-implemented steps <NUM> for managing a power state of a wireless station (STA) for cooperative multi-band operation using a QoS Null frame and a QoS Data frame depicted for a wireless network according to embodiments of the present invention.

At step <NUM>, as depicted in <FIG>, a QoS Null frame is transmitted from the STA to the AP using a first band, where the STA and the AP are in wireless communication using the first band and a second band. The QoS Null frame triggers a service period (SP) for the first band and the second band.

At step <NUM>, a power management mode of the STA is updated for the second band according to a first EOSP subfield of the QoS Null frame, where the second band is identified by a band information subfield of the QoS Null frame.

At step <NUM>, a power management mode of the STA is updated for the first band according to a second EOSP subfield of the QoS Null frame.

At step <NUM>, a QoS Data frame is received from the AP at the STA using the second band, and a power management mode of the STA is updated for the second band according to a first EOSP subfield of the QoS Data frame.

At step <NUM>, a power management mode of the STA is updated for the second band according to a first EOSP subfield of the QoS Data frame.

At step <NUM>, a power management mode of the STA is updated for the first band according to a second EOSP subfield of the QoS Data frame, where the first band is indicated by a band information subfield of the QoS Data frame.

Embodiments of the present invention are drawn to electronic systems for performing power management for cooperative multi-band operations in a wireless network. The following discussion describes one such exemplary electronic system or computer system can be used as a platform for implementing embodiments of the present invention.

In the example of <FIG>, the exemplary computer system <NUM> (e.g., a multi-band cooperative wireless access point AP or a multi-band cooperative wireless station STA) includes a central processing unit (CPU) <NUM> for running software applications and optionally an operating system. Random access memory <NUM> and read-only memory <NUM> store applications and data for use by the CPU <NUM>. Data storage device <NUM> provides non-volatile storage for applications and data and may include fixed disk drives, removable disk drives, flash memory devices, and CD-ROM, DVD-ROM or other optical storage devices. The optional user inputs <NUM> and <NUM> comprise devices that communicate inputs from one or more users to the computer system <NUM> (e.g., mice, joysticks, cameras, touch screens, and/or microphones).

A communication or network interface <NUM> includes a plurality of transceivers and allows the computer system <NUM> to communicate with other computer systems, networks, or devices via an electronic communications network, including wired and/or wireless communication and including an Intranet or the Internet (e.g., <NUM> wireless standard). The communication or network interface <NUM> can operate multiple transceivers simultaneously e.g., Transceiver <NUM> and Transceiver <NUM>. The communication or network interface <NUM> can further include a cooperative management unit for coordinating the data sent and/or received by the transceivers. The communication or network interface <NUM> and can include a dual band interface that can operate in multiple bands simultaneously, such as <NUM>, <NUM>, and/or <NUM>. Power management operations are performed by an AP or non-AP STA to control the status (e.g., active or doze) of the non-AP STA over specific bands, for example, to conserve power.

The optional display device <NUM> may be any device capable of displaying visual information in response to a signal from the computer system <NUM> and may include a flat panel touch sensitive display, for example. The components of the computer system <NUM>, including the CPU <NUM>, memory <NUM>/<NUM>, data storage <NUM>, user input devices <NUM>, and graphics subsystem <NUM> may be coupled via one or more data buses <NUM>.

Some embodiments may be described in the general context of computer-executable instructions, such as program modules, executed by one or more computers or other devices.

Claim 1:
A method of managing a power state of a wireless station, in the following also referred to as STA (<NUM>), for cooperative multi-band operation between the STA and a wireless access point, in the following also referred to as AP (<NUM>), for a wireless network, the method comprising:
receiving a frame transmitted from the AP to the STA over a first band, said frame comprising a Frame Control field (<NUM>) comprising a More Data, in the following also referred to as MD, field (<NUM>) indicating a buffer status of a second band; and
updating a power management mode of the STA for the second band according to the buffer status of the second band received from the STA over the first band.