Patent Description:
The IEEE (Institute of Electrical and Electronics Engineers) <NUM> Working Group is defining a PHY (physical) layer specification and modifications on MAC (Medium Access Control) layer specification that enable operation of a WUR (Wake Up Radio) apparatus. The WUR apparatus is a companion radio apparatus to a PCR (Primary Connectivity Radio) apparatus, e.g., IEEE <NUM>. 11a/g/n/ac/ax radio apparatus. The WUR apparatus comprises a WURx (Wake Up Receiver) which is capable of receiving WUR frames. The PCR apparatus included in a wireless communication device is used for user data communication with the access point (AP) with which the device is associated; while the WUR apparatus included in the device is not used for user data communication. For a wireless communication device operating in WUR Mode, when the PCR apparatus of the device is in the doze state, the WURx of the device follows the duty cycle schedules negotiated between the device and the AP. Once the WURx of the device receives WUR Wake-up frame, the PCR apparatus of the device transits to the awake state.

NPL <NUM>: <NPL>, relates to WUR operation in Wireless LAN. In particular, a WUR Mode Setup frame format is described. The WUR Mode Setup frame is an Action frame of category WUR and contains information on a category, a WUR Action, a Dialog Token, and a WUR Mode element.

<NPL>, discloses that an AP may negotiate one or more Group IDs with an ST through PCR.

Studies are underway on how a wireless communication device is able to perform WUR mode operation in an efficient manner.

One non-limiting and exemplary embodiment of the present disclosure facilitates performing WUR mode operation in an efficient manner.

The invention is directed to the second embodiment. The remaining embodiments are only for explanatory and illustrational purposes.

By taking advantage of the communication apparatus and the communication method described in the present disclosure, a wireless communication device is able to perform WUR mode operation in an efficient manner.

The present disclosure can be better understood with the aid of following figures and embodiments. The embodiments described here are merely exemplary in nature and are used to describe some of the possible applications and uses of the present disclosure and should not be taken as limiting the present disclosure with regard to alternative embodiments that are not explicitely described herein.

In any wireless communication system, a wide variety of devices may be a part of the wireless network, each device differing in terms of traffic needs, device capabilities, power supply types and so on. Some class of devices may have less bandwidth requirements and also less stringent QoS (Quality of Service) requirements but may be relatively more concerned about power consumption (e.g., mobile phones). Another class of devices may have low bandwidth requirements as well as very low duty cycles but may be very sensitive to power consumption due to extremely small batteries or extremely long life expectancy (e.g., sensors for remote sensing).

In many wireless communication systems, there will be one or more central controllers which will determine the wireless network coverage area, the wireless frequency channels, the device admission policy, coordination with other neighboring wireless networks etc. and usually also act as a gateway to the backend infrastructure network. Examples of the central controllers are base stations or eNBs in cellular wireless networks or APs in WLANs (Wireless Local Area Networks).

Even though the techniques described in the present disclosure may apply to many wireless communication systems, for the sake of example, the rest of the descriptions in this disclosure are described in terms of an IEEE <NUM> based WLAN system and its associated terminologies. This should not be taken as limiting the present disclosure with regard to alternative wireless communication systems. In IEEE <NUM> based WLANs, majority of networks operate in infrastructure mode, i.e., all or most of the traffic in the network need to go through the AP. As such, any STA (station) wishing to join the WLAN must first negotiate the network membership with the AP through a process called association and authentication.

<FIG> illustrates an example wireless network <NUM> including an AP <NUM> and a plurality of STAs associated with the AP <NUM>. The plurality of STAs form a BSS (Basic Service Set) of the AP <NUM>. The AP <NUM> includes a PCR apparatus (hereinafter stated simply as "PCR") <NUM>. The STA 130represents a device class that may have less bandwidth requirements and also less stringent QoS requirements but may be relatively more concerned about power consumption. The STA 140represents another class of devices that may have low bandwidth requirements but may be very sensitive to power consumption. In order to maximise energy efficiency, the STA <NUM> is equipped with a WUR apparatus <NUM> (hereinafter stated simply as "WUR") in addition to a PCR <NUM> and the STA <NUM> is equipped with a WUR <NUM> in addition to a PCR <NUM>. Both the STA <NUM> and the STA <NUM> are termed as WUR STAs thereafter.

According to the present disclosure, the PCR of a WUR STA can operate in either of the two power management modes: active mode and PS (power save) mode. For the PCR of a WUR STA operating in PS mode, it is in the awake state when it is able to receive DL (downlink) traffic or transmit UL (uplink) traffic; and it is in the doze state when it is not able to receive DL traffic and transmit UL traffic. For the PCR of a WUR STA operating in active mode, it is always in the awake state.

According to the present disclosure, the WUR of a WUR STA comprises a WURx which is capable of receiving WUR frames. The WURx of a WUR STA can be in either of the two states: WURx Awake or WURx Doze. The WURx of a WUR STA is in the WURx Awake state when it is able to receive WUR frames. The WURx of a WUR STA is in the WURx Doze state when it is not able to receive WUR frames.

According to the present disclosure, a WUR STA can operate in WUR Mode Suspend or WUR Mode. When a WUR STA operates in WUR Mode, its WURx shall be in the WURx Awake state during the on durations of WUR duty cycle schedules negotiated between the AP <NUM> and the WUR STA if the PCR of the WUR STA is in the doze state; and its WURx may be in the WURx Doze state after the WUR STA uses its PCR to complete a successful frame exchange with the AP <NUM>, which informs the AP <NUM> that the PCR of the WUR STA is the awake state. When a WUR STA operates in WUR Mode Suspend, its WURx may be in the WURx Doze state; and the WUR parameters negotiated between the AP 110and the WUR STA are maintained by the WUR STA and the AP <NUM>.

<FIG> illustrates example WUR mode operation related MAC procedures operated by a WUR STA and the AP <NUM> according to the present disclosure. Before the WUR STA is associated with the AP <NUM>, its PCR is in active mode. The STA initiates a synchronization procedure 210to acquire synchronization with the AP 110via passive or active scanning. During the synchronization procedure <NUM>, if active scanning is performed, the STA sends a Probe Request frame to the AP <NUM> via its PCR. The Probe Request frame includes a WUR Capabilities element (see <FIG>) advertising WUR capabilities of the STA. The AP <NUM> responds with a Probe Response frame. The Probe Response frame includes a WUR Capabilities element advertising WUR capabilities of the AP <NUM> and a WUR Operation element (see <FIG>) announcing WUR parameters which are common to all WUR STAs. If passive scanning is performed, the STA receives a Beacon frame from the AP 110via its PCR. The Beacon frame contains a WUR Capabilities element which advertises WUR capabilities of the AP <NUM> and a WUR Operation element announcing WUR parameters which are common to all WUR STAs. The formats of the Probe Request, Probe Response and Beacon frames are defined in the IEEE Std <NUM>™-<NUM>.

<FIG> illustrates an example format of the WUR Capabilities element <NUM> according to the present disclosure. The WUR Capabilities element <NUM> indicates WUR capabilities of the WUR STA or the AP <NUM> transmitting the element <NUM> and comprises a Supported Bands field <NUM>, a PCR Transition Delay field <NUM>, a Nonzero Length Frame Body Support field <NUM> and a Supported Group IDs field <NUM>. The Supported Bands field <NUM> indicates supported bands for WUR mode operation. The PCR Transition Delay field <NUM> indicates PCR transition delay from the doze state to the awake state of the WUR STA transmitting the element <NUM> after receiving WUR Wake-up frame. The Nonzero Length Frame Body Support field <NUM> indicates supportability of non-zero length frame body of WUR frame (see <FIG>). The Supported Group IDs field <NUM> indicates the group ID bitmap size that the WUR STA transmitting the element <NUM> is capable of storing. The group ID bitmap size (i.e., number of bits in the group ID bitmap) that the WUR STA is capable of storing shall not be larger than the number of group IDs that can be provided by the AP <NUM>. For example, if <NUM> group IDs can be provided by the AP <NUM>, the group ID bitmap size that the WUR STA is capable of storing can be <NUM> bits, <NUM> bits, <NUM> bits or <NUM> bits. In this case, the Supported Group IDs field <NUM> may have a size of <NUM> bits. The Supported Group IDs field <NUM> is set to <NUM> to indicate that the WUR STA does not support the reception of group ID based multicast WUR Wake-up frames. The Supported Group IDs field <NUM> is set to <NUM>, <NUM>, <NUM> and <NUM> to indicate that the WUR STA is capable of storing <NUM>-bit, <NUM>-bit, <NUM>-bit and <NUM>-bit group ID bitmap, respectively. The Supported Bands field <NUM>, the PCR Transition Delay field <NUM>, the Nonzero Length Frame Body Support field <NUM> and the Supported Group IDs field <NUM> are reserved when the element <NUM> is transmitted by the AP <NUM>.

<FIG> illustrates an example format of the WUR Operation element <NUM> according to the present disclosure. The WUR Operation element <NUM> contains WUR parameters which are controlled by an AP and are common to all WUR STAs in the BSS of the AP. The WUR Operation element <NUM> comprises a Duty Cycle Period Unit field <NUM>, a Minimum On Duration field <NUM>, a WUR Operating Class field <NUM> and a WUR Beacon Period field <NUM>. The Duty Cycle Period Unit field <NUM> indicates the basic unit of the period of the WUR duty cycle operation, which is a multiple of time unit (<NUM>) defined in the IEEE Std <NUM>™-<NUM> for easy of implementation. The Minimum On Duration field <NUM> indicates a minimum value of the on duration of a WUR duty cycle schedule, which is a multiple of time unit (<NUM>) defined in the IEEE Std <NUM>™-<NUM> for easy of implementation. The WUR Operating Class field <NUM> indicates the operating class in use for transmission of WUR frame from the AP <NUM> to the associated WUR STAs. The WUR Beacon Period field <NUM> indicates the period of WUR Beacon frame.

After the WUR STA gets synchronized with the AP <NUM> via the synchronization procedure <NUM>, it may initiate an association procedure <NUM> with the AP <NUM>. During the association procedure <NUM>, the STA sends an Association Request frame or a Reassociation Request frame to the AP <NUM>, which includes a WUR Capabilities element for advertising WUR capabilities of the STA. The AP 110responds with an Association Response frame or a Reassociation Response frame, which includes a WUR Capabilities element for advertising WUR capabilities of the AP <NUM> and a WUR Operation element for announcing WUR parameters which are common to all WUR STAs. The formats of the Association Request, Association Response, Reassociation Request and Reassociation Response frames are defined in the IEEE Std <NUM>™ - <NUM>.

The STA may initiate a power management mode change procedure <NUM> for changing its PCR's power management mode to PS mode after it is associated with the AP <NUM> via the association procedure <NUM> with the AP <NUM>. During the power management mode change procedure <NUM>, the STA may transmit a QoS Null frame via its PCR with the Power Management subfield set to <NUM> to the AP <NUM>; and the AP <NUM> will respond with an Ack frame. After receiving the Ack frame, the STA's PCR transits to operate in PS mode. After that, the STA may initiate a WUR negotiation procedure <NUM> with the AP <NUM> to negotiate user-specific WUR parameters. The formats of the QoS Null and Ack frames are defined in the IEEE Std <NUM>™-<NUM>.

<FIG> illustrates an example WUR negotiation procedure according to the present disclosure. The WUR STA transmits a WUR Mode Setup frame <NUM> (see <FIG>) via its PCR to the AP <NUM>. The WUR Mode Setup frame <NUM> comprises a WUR Mode element (see <FIG>) in which the Action Type field is set to "Enter WUR Mode Suspend Request" (see <FIG>) and the WUR Parameters field (see <FIG>) contains the WUR parameters preferred by the STA. The AP 110responds with an Ack frame upon succesful receipt of the WUR Mode Setup frame <NUM>. After that, the AP <NUM> transmits a WUR Mode Setup frame <NUM> to the STA. The WUR Mode Setup frame <NUM> comprises a WUR Mode element in which the Action Type field is set to "Enter WUR Mode Suspend Response" and the WUR Mode Response Status field is set to "Accept" or "Denied". If the WUR Mode Response Status field of the WUR Mode element in the WUR Mode Setup frame <NUM> is set to "Accept", the WUR Parameters field of the same WUR Mode element (see <FIG>) contains WUR parameters determined by the AP <NUM>. If the WUR Mode Response Status field sets to "Denied", the WUR Parameters field is not present. The STA responds with an Ack frame via its PCR upon succesful receipt of the WUR Mode Setup frame <NUM>.

If the WUR negotiation procedure <NUM> is successfully completed (i.e., the WUR Mode Response Status field of the WUR Mode element in the WUR Mode Setup frame <NUM> is set to "Accept"), the WUR STA enters WUR Mode Suspend. Then the WUR STA may initiate a WUR mode entry procedure <NUM> with the AP <NUM> to switch to WUR Mode from WUR Mode Suspend for better power save. <FIG> illustrates an example WUR mode entry procedure <NUM> according to the present disclosure. The WUR STA transmits a WUR Mode Setup frame via its PCR to the AP <NUM>. The WUR Mode Setup frame comprises a WUR Mode element in which the Action Type field is set to "Enter WUR Mode" and the WUR Parameters field is not present. The AP <NUM> responds with an Ack frame upon succesful receipt of the WUR Mode Setup frame. After receiving the Ack frame, the STA operates in WUR Mode according to the WUR parameters negotiated between the AP <NUM> and the STA during the WUR negotiation procedure <NUM>. In more details, the WURx of the STA operating in WUR Mode follows the duty cycle schedules negotiated between the AP 110and the STA if the PCR of the STA is in the doze state.

Alternatively, instead of separate WUR negotiation procedure <NUM> and WUR mode entry procedure <NUM>, the STA may initiate an integrated WUR negotiation and WUR mode entry procedure with the AP <NUM> for requesting to enter WUR Mode. During the integrated WUR negotiation and WUR mode entry procedure, the STA transmits a WUR Mode Setup frame via its PCR to the AP <NUM>. The WUR Mode Setup frame comprises a WUR Mode element in which the Action Type field is set to "Enter WUR Mode Request" and the WUR Parameters field contains WUR parameters preferred by the STA. The AP <NUM> responds with an Ack frame upon succesful receipt of the WUR Mode Setup frame. After that, the AP <NUM> transmits a WUR Mode Setup frame to the STA. The WUR Mode Setup frame comprises a WUR Mode element in which the Action Type field is set to "Enter WUR Mode Response" and the WUR Mode Response Status field is set to "Accept" or "Denied". If the WUR Mode Response Status field is set to "Accept", the WUR Parameters field contains WUR parameters determined by the AP <NUM>. If the WUR Mode Response Status field is set to "Denied", the WUR Parameters field is not present. The STA responds with an Ack frame via its PCR upon succesful receipt of the WUR Mode Setup frame.

According to the present disclosure, if the PCR of the WUR STA operating in WUR Mode is in the doze state, when its WURx receives WUR Wake-up frame from the AP <NUM>, its PCR transits to the awake state as shown in <FIG>, and then initiates a DL data transmission and acknowledgement procedure <NUM> with the AP <NUM>. During the DL data transmission and acknowledgement procedure <NUM>, it may transmit a PS-Poll frame to the AP <NUM> via its PCR to retrieve buffered traffic and acknowledge successful receipt of the WUR Wake-up frame. The AP 110responds to the PS-Poll frame with a buffered QoS Data frame or an Ack frame followed in a separate TXOP (transmit opportunity) by a buffered QoS Data frame at the head of transmit queue. If there is more buffered traffic for the STA, the More Data field in the delivered QoS Data frame is set to <NUM>. Otherwise, the More Data field in the delivered QoS Data frame is set to <NUM>. The STA responds with an acknowledgement frame via its PCR for acknowledging successful receipt of the QoS Data frame. The acknoweldgement frame is either an Ack frame or a BlockAck frame. The formats of the QoS Data and BlockAck frames are defined in the IEEE Std <NUM>™-<NUM>.

According to the present disclosure, when the WUR STA intends to tear down WUR Mode, it initiates a WUR mode exit procedure <NUM> with the AP <NUM>. <FIG> illustrates an example WUR mode exit procedure 260according to the present disclosure. The STA transmits a WUR Mode Teardown frame (see <FIG>) via its PCR to the AP <NUM>. The AP <NUM> responds with an Ack frame upon successful receipt of the WUR Mode Teardown frame. After receiving the Ack frame, the STA tears down WUR Mode.

<FIG> illustrates an example format of the WUR Mode Setup frame or WUR Mode Teardown frame <NUM> according to the present disclosure. The frame <NUM> comprises a Frame Body field <NUM>. The frame <NUM> is a WUR Action frame and the WUR Action field <NUM> of the Frame Body field <NUM> indicates whether the frame <NUM> is WUR Mode Setup frame or WUR Mode Teardown frame. If the frame 500is WUR Mode Setup frame, the Frame Body field <NUM> may comprise a WUR Mode element <NUM>. Otherwise the WUR Mode element <NUM> is not present.

<FIG> illustrates an example format of the WUR Mode element <NUM> according to the present disclosure. The WUR Mode element <NUM> comprises an Action Type field <NUM> and a WUR Mode Response Status field <NUM>. The WUR Mode element <NUM> may comprises a WUR Parameters field <NUM>. The Action Type field <NUM> is defined in <FIG> and indicates the action taken by the WUR Mode Setup frame containing the WUR Mode element <NUM>. The WUR Mode Response Status field <NUM> indicates whether the request for entering WUR Mode Suspend or WUR Mode is accepted or denied. The WUR Parameters field <NUM> contains user-specific WUR parameters either preferred by a WUR STA or determined by the AP <NUM>.

<FIG> illustrates an example format of the WUR Parameters field <NUM> of the WUR Mode element 524transmitted by a WUR STA according to the present disclosure. The WUR Parameters field <NUM> of the WUR Mode element <NUM> transmitted by the STA comprises an On Duration field 802and a Duty Cycle Period field <NUM>. The On Duration field <NUM> indicates the preferred on duration of each WUR duty cycle schedule, during which the STA's WURx will be in the WURx Awake state. The preferred on duration is a multiple of time unit (<NUM>) defined in the IEEE Std <NUM>™-<NUM> for easy of implementation and shall be larger than or equal to the minimum on duration indicated by the Minimum On Duration field <NUM> in the most recently received WUR Operation element <NUM> from the AP <NUM>. The Duty Cycle Period field <NUM> indicates the preferred elapsed time between the start times of two successive WUR duty cycle schedules. The Duty Cycle Period field <NUM> is based on the unit indicated by the Duty Cycle Period Unit field <NUM> in the most recently received WUR Operation element <NUM> from the AP <NUM>.

<FIG> illustrates an example format of the WUR Parameters field <NUM> of the WUR Mode element 524transmitted by the AP <NUM> according to the present disclosure. The WUR Parameters field <NUM> of the WUR Mode element 524transmitted by the AP <NUM> comprises a Wake-up ID (identifier) field <NUM>, a Duty Cycle Information field <NUM>, a WUR Channel field <NUM> and a Group ID List field <NUM>. The Wake-up ID field <NUM> indicates the Wake-up ID assigned by the AP <NUM> to the intended WUR STA, which uniquely identifies the intended WUR STA in the BSS of the AP <NUM>.

The Duty Cycle Information field <NUM> comprises a Starting Point field <NUM>, a On Duration field 824and a Duty Cycle Period field <NUM>. The Starting Point field 822indicates the TSF (Time Synchronization Function) time of the starting point of the intended STA's WUR duty cycle schedule. The On Duration field <NUM> indicates the determined on duration of each WUR duty cycle schedule, during which the intended STA's WURx will be in the WURx Awake state. The determined on duration is a multiple of time unit (<NUM>) defined in the IEEE Std <NUM>™-<NUM> for easy of implementation and shall be larger than or equal to the minimum on duration indicated by the Minimum On Duration field 354in the most recently transmitted WUR Operation element <NUM>. The Duty Cycle Period field <NUM> indicates the determined elapsed time between the start times of two successive WUR duty cycle schedules. The Duty Cycle Period field <NUM> is based on the unit indicated by the Duty Cycle Period Unit field 352in the most recently transmitted WUR Operation element <NUM>. Notice that for a WUR STA operating in WUR Mode, when the determined on duration is equal to the determined duty cycle period, its WURx is always in the WURx Awake state if its PCR is in the doze state.

The WUR Channel field 830indicates the channel in use for transmission of WUR frame from the AP <NUM> to the intended WUR STA.

The Group ID List field 840contains the information on group IDs assigned by the AP <NUM> to the intended WUR STA. A group ID uniquely identifies a group of WUR STAs in the BSS of the AP <NUM>. The format of the Group ID List field <NUM> will be detailed later.

<FIG> illustrates an example format of the WUR frame <NUM> according to the present disclosure. The WUR frame 1100comprises a Frame Control field <NUM>, an Address field <NUM> and a TD (type dependent) Control field <NUM>. The WUR frame <NUM> may comprise a Frame Body field <NUM>. The Frame Control field <NUM> comprises a Type subfield <NUM>, a Frame Body Presence subfield 1114and a Length/Misc subfield <NUM>. The Type subfield <NUM> defines the type of the WUR frame <NUM>, as defined in <FIG>. In particular, the WUR frame <NUM> with the Type subfield <NUM> of the Frame Control field <NUM> set to <NUM> is WUR Wake-up frame. The Frame Body Presence subfield 1114indicates the presence of the Frame Body field <NUM> in the WUR frame <NUM>. The Length/Misc subfield <NUM> contains the length of the Frame Body field 1140if the Frame Body field <NUM> is present in the WUR frame <NUM> and contains bits that are expected to be used for other purposes otherwise.

The Address field 1120contains an identifier for the WUR frame <NUM>. The identifier contained in the Address field <NUM> depends on the type of the WUR frame <NUM>. In particular, as defined in <FIG>, the Address field 1120contains the Wake-up ID of the intended WUR STA when the WUR frame <NUM> is unicast (i.e., individually addressed) WUR Wake-up frame, the group ID of the intended group of WUR STAs when the WUR frame <NUM> is multicast (i.e., group addressed) WUR Wake-up frame, or the Transmit ID when the WUR frame <NUM> is broadcast WUR Wake-up frame or WUR Beacon frame. Each of Wake-up ID, group ID and Transmit ID has a size of <NUM> bits. The <NUM>-bit TD Control field <NUM> contains control information that depends on the type of the WUR frame <NUM>. For example, if the WUR frame <NUM> is WUR Beacon frame, the TD Control field 1130contains partial TSF.

According to the present disclosure, the WUR Wake-up frame <NUM> with the Address field <NUM> set to a first special ID (e.g., 0x000) comprises the Frame Body field <NUM> which contains two or more Wake-up IDs. In this case, this WUR Wake-up frame <NUM> is used to wake up two or more WUR STAs. The first special ID is fixed or randomly selected by the AP <NUM> within the identifier's space. If the first special ID is randomly selected by the AP <NUM> within the identifier's space, it can be indicated in the First Special ID field <NUM> the the WUR Operation element <NUM>. As a result, collision among the first special IDs within the BSSs of neighboring APs can be minimized.

According to the present disclosure, the WUR Wake-up frame <NUM> with the Address field <NUM> set to a second special ID is used to indicate that the AP 110intends to transmit group addressed frames. The second special ID is fixed or randomly selected by the AP <NUM> within the identifier's space. If the second special ID is randomly selected by the AP <NUM> within the identifier's space, it can be indicated in the Second Special ID field <NUM> the the WUR Operation element <NUM>. As a result, collision among the second special IDs within the BSSs of neighboring APs can be minimized.

According to the present disclosure, the Wake-up IDs assigned by the AP <NUM> to the associated WUR STAs, the group IDs assigned by the AP <NUM> to the associated WUR STAs, the first special ID, the second special ID and the Transmit ID of the AP <NUM> shall be different. As a result, a WUR STA is able to identify whether it is the intended recipient of a received WUR Wake-up frame based on its Address field, as illustrated in <FIG>.

According to the present disclosure, the value range of group ID is a subset of consecutive values obtained from the identifier's space. The value range of group ID is configurable so that the value range of group ID for the BSSs of different APs may be different. As a result, the probability of assigning the same group ID by different APs is minimized, which is instrumental for a WUR STA to filter multicast WUR Wake-up frames properly using the Address field.

<FIG> illustrates an example identifier's space according to the present disclosure. The identifier's space contains <NUM> identifiers. In this example, the first special ID is <NUM>, the second special ID is <NUM> and the Transmit ID of the AP <NUM> is <NUM>. The Wake-up ID assigned by the AP <NUM> to a specific WUR STA can be randomly selected from the value range of <NUM> to <NUM>, <NUM> to <NUM> and <NUM> to <NUM>. The group ID assigned by the AP <NUM> to a specific group of WUR STAs can be randomly selected from the value range of <NUM> to <NUM> which contains consecutive <NUM> identifiers. In this example, the number of group IDs that can be provided by the AP <NUM> is <NUM>.

According to the present disclosure, when a WUR STA receives a WUR PPDU containing WUR Wake-up frame, it may decode the Address field of the WUR Wake-up frame and perform a frame filtering procedure first.

<FIG> illustrates an example frame filtering procedure <NUM> according to the present disclosure. The procedure 1400starts at step <NUM>. At step <NUM>, the STA determines whether the identifier contained in the Address field of the received WUR Wake-up frame matches to its assigned Wake-up ID, any of its assigned group IDs, the first special ID or the Transmit ID of the AP <NUM>. If the identifier contained in the Address field of the received WUR Wake-up frame matches to its assigned Wake-up ID, any of its assigned group IDs, the first special ID or the Transmit ID of the AP <NUM>, the procedure <NUM> proceeds to step <NUM>. Otherwise at step <NUM> the STA determines whether the identifier contained in the Address field of the received WUR Wake-up frame matches to the second special ID. If the identifier contained in the Address field of the received WUR Wake-up frame does not match to the second special ID, the procedure <NUM> proceeds to step <NUM>. Otherwise at step <NUM> the STA determines whether it intends to receive group addressed frames. If it intends to receive group addressed frames, at step <NUM> the STA decodes the fields following the Address field of the received WUR Wake-up frame. Otherwise at step <NUM> the STA discards the received WUR Wake-up frame. The procedure <NUM> stops at step <NUM>.

According to the present disclosure, when a WUR STA receives a WUR PPDU containing WUR Wake-up frame, by performing a frame filtering procedure <NUM> as illustrated in <FIG>, the STA may decide not to decode the fields following the Address field of the WUR Wake-up frame and therefore power consumption of the STA can be reduced.

According to the present disclosure, the Wake-up ID assigned by the AP <NUM> to a WUR STA is indicated in the Wake-up ID field <NUM> of the WUR Parameters field <NUM> in the WUR Mode element 524transmitted by the AP <NUM> (see <FIG>) during the WUR negotiation procedure (see <FIG> and <FIG>) between the AP 110and the STA.

According to the present disclosure, the Transmit ID of the AP <NUM> is algorithmically obtained from the BSSID (Basic Service Set Identifier) of the AP <NUM>. As a result, collision among Transmit IDs of neighboring APs can be minimized.

According to the present disclosure, information on group IDs assigned by the AP <NUM> to a WUR STA is indicated in the Group ID List field <NUM> of the WUR Parameters field <NUM> in the WUR Mode element <NUM> transmitted by the AP <NUM> during the WUR negotiation procedure between the AP <NUM> and the STA.

<FIG> illustrates an example format of the Group ID List field <NUM> of the WUR Parameters field <NUM> in the WUR Mode element 524transmitted by the AP <NUM> according to a first embodiment of the present disclosure. The Group ID List field <NUM> comprises a Number of Groups field <NUM> and a Group ID Tuples field <NUM>. The Number of Groups field <NUM> indicates the number of groups the intended WUR STA belongs to. If the intended WUR STA does not support the reception of group ID based multicast WUR Wake-up frames, the Number of Groups field <NUM> shall be set to <NUM>. The Group ID Tuples field <NUM> contains group ID for each of the groups the intended WUR STA belongs to.

According to the first embodiment of the present disclosure, the encoding of the Number of Group IDs field <NUM> is 0b0110, while the encoding of the Group ID Tuples field <NUM> is 0x101 <NUM>10A 10C 10E 11F. In this example, the signaling overhead for the Group ID List field <NUM> is <NUM> bits.

According to the first embodiment of the present disclosure, after receiving the WUR Mode element <NUM> transmitted by the AP <NUM>, for easy of storing group ID information, the WUR STA may reorganize the Group ID List field <NUM> into at least one group ID and a group ID bitmap whose size is not larger than the group ID bitmap size that it is capable of storing. In this case, for minimizing the memory requirement for storing group ID information, the AP 110may assign group IDs to the WUR STA in such a manner that as many as assigned group IDs can be indicated by a group ID bitmap that the WUR STA is capable of storing and a group ID corresponding to bit <NUM> of the group ID bitmap.

<FIG> illustrates a format of the Group ID List field <NUM> of the WUR Parameters field <NUM> in the WUR Mode element 524transmitted by the AP <NUM> according to a second embodiment of the present disclosure. The Group ID List field <NUM> comprises a Smallest Group ID field <NUM> and a Group ID Bitmap field <NUM>. The Smallest Group ID field <NUM> indicates the smallest group ID that can be provided by the AP <NUM>. The Group ID Bitmap field <NUM>, together with the Smallest Group ID field <NUM>, indicates Group IDs which are assigned by the AP <NUM> to the intended WUR STA. The size of the Group ID Bitmap field <NUM> is the same as the number of group IDs that can be provided by the AP <NUM>(e.g., <NUM>). The Group ID Bitmap field <NUM> starts with the LSB (Least Significant Bit) (i.e., bit <NUM>). The group IDs assigned by the AP <NUM> to the intended WUR STA equal to the smallest group ID indicated in the Smallest Group ID field <NUM> plus the bit position when the bit in the Group ID Bitmap field <NUM> is set to <NUM>. If the intended WUR STA does not support the reception of group ID based multicast WUR Wake-up frames, the Group ID Bitmap field <NUM> shall be set to all <NUM>.

According to the second embodiment of the present disclosure, the encoding of the Smallest Group ID field <NUM> is 0x100, and the encoding of the Group ID Bitmap field <NUM> is 0x80005422. In this example, the signaling overhead for the Group ID List field <NUM> is <NUM> bits. So the second embodiment may result in less signaling overhead than the first embodiment.

According to the second embodiment of the present disclosure, alternatively, the smallest group ID that can be provided by the AP <NUM> can be indicated in the Smallest Group ID field <NUM> in the WUR Operation element <NUM> since the smallest group ID that can be provided by the AP <NUM> is a common WUR parameter to all WUR STAs. In this case, the group IDs assigned by the AP <NUM> to the intended WUR STA equal to the smallest group ID indicated in the Smallest Group ID field <NUM> in the most recently received WUR Operation element 350plus the bit position when the bit in the Group ID Bitmap field <NUM> is set to <NUM>.

According to the second embodiment of the present disclosure, If the group ID bitmap size that the intended WUR STA is capable of storing is smaller than the number of group IDs that can be provided by the AP <NUM>, the WUR STA cannot directly store the group ID bitmap contained in the Group ID Bitmap field <NUM> in the received WUR Mode element <NUM>. As a result, after receiving the WUR Mode element 524transmitted by the AP <NUM>, for easy of storing group ID information, the WUR STA may reorganize the Group ID List field <NUM> into at least one group ID and a group ID bitmap with size not larger than the group ID bitmap size that it is capable of storing. In this case, for minimizing the memory requirement for storing group ID information, the AP 110may assign group IDs to the WUR STA in such a manner that as many as assigned group IDs can be indicated by a group ID bitmap that the WUR STA is capable of storing and a group ID corresponding to bit <NUM> of the group ID bitmap.

<FIG> illustrates an example format of the Group ID List field <NUM> of the WUR Parameters field <NUM> in the WUR Mode element 524transmitted by the AP <NUM> according to a third embodiment of the present disclosure. The Group ID List field <NUM> comprises a Number of Group IDs field <NUM>, a Group ID Tuples field <NUM>, a Group ID Bitmap Size field <NUM>, a Group ID Bitmap Start field <NUM> and a Group ID Bitmap field <NUM>. The Number of Group IDs field <NUM> indicates the number of group IDs which are assigned by the AP <NUM> to the intended WUR STA and contained in the Group ID Tuples field <NUM>. The Group ID Bitmap Size field <NUM> indicates the size of the Group ID Bitmap field <NUM>. If the number of group IDs that can be provided by the AP <NUM> is <NUM>, the Group ID Bitmap Size field <NUM> may have a size of <NUM> bits. In this case, the Group ID Bitmap Size field <NUM> is set to <NUM> to indicate that the Group ID Bitmap Start field <NUM> and the Group ID Bitmap field <NUM> are not present. The Group ID Bitmap Size field <NUM> is set to <NUM>, <NUM>, <NUM> or <NUM> to indicate that the Group ID Bitmap field <NUM> contains a <NUM>-bit, <NUM>-bit, <NUM>-bit or <NUM>-bit bitmap. The Group ID Bitmap Start field <NUM> indicates the group ID corresponding to the LSB (i.e., bit <NUM>) of the Group ID Bitmap field <NUM>. The Group ID Bitmap Start field <NUM> shall be set in such a manner that the group ID bitmap does not indicate any group ID out of the Group ID value range. The Group ID Bitmap field <NUM> indicates the remaining group IDs which are assigned by the AP <NUM> to the intended WUR STA. The remaining group IDs assigned by the AP <NUM> to the intended WUR STA equal to the group ID indicated in the Group ID Bitmap Start field <NUM> plus the bit position when the bit in the Group ID Bitmap field <NUM> is set to <NUM>. The size of the Group ID Bitmap field <NUM> shall not be larger than the group ID bitmap size that the intended WUR STA is capable of storing. If the intended WUR STA does not support the reception of group ID based multicast WUR Wake-up frames, both the Number of Group IDs field 1702and the Group ID Bitmap Size field 1706shall be set to <NUM>.

According to the third embodiment of the present disclosure, after receiving the WUR Mode element <NUM> transmitted by the AP <NUM>, the WUR STA can directly store Group ID information based on the Group ID Tuples field <NUM>, the Group ID Bitmap Start field <NUM> and the Group ID Bitmap field <NUM>. In this case, for minimizing the memory requirement for storing group ID information, the AP 110may assign group IDs to the WUR STA in such a manner that as many as assigned group IDs can be indicated by a group ID bitmap contained in the Group ID Bitmap field <NUM> and a group ID contained in the Group ID Bitmap Start field <NUM>. Since it is unnecessary for the WUR STA to reorganize the Group ID List field <NUM> into at least one group ID and a group ID bitmap with size not larger than the group ID bitmap size that it is capable of storing, implementation complexity of the WUR STA is reduced.

According to the third embodiment of the present disclosure, the encoding of the Number of Group IDs field <NUM> is 0b0001, the encoding of the Group ID Tuples field <NUM> is 0x11F, the encoding of the Group ID Bitmap Size field <NUM> is 0b010, the encoding of the Group ID Bitmap Start field <NUM> is 0x101 and the encoding of the Group ID Bitmap field <NUM> is 0x2A11. In this example, the signaling overhead for the Group ID List field <NUM> is <NUM> bits. The memory required for storing the group ID information is <NUM> bits.

<FIG> illustrates an example format of the Group ID List field <NUM> of the WUR Parameters field <NUM> in the WUR Mode element 524transmitted by the AP <NUM> according to a fourth embodiment of the present disclosure. The Group ID List field <NUM> comprises a Number of Group IDs field <NUM>, a Group ID Tuples field <NUM>, a Group ID Bitmap Size field <NUM>, a Group ID Bitmap field <NUM> and a Smallest Group ID field <NUM>. The Number of Group IDs field <NUM> indicates the number of group IDs which are assigned by the AP <NUM> to the intended WUR STA and contained in the Group ID Tuples field <NUM>. The Group ID Bitmap Size field <NUM> indicates the size of the Group ID Bitmap field <NUM>. If the number of group IDs that can be provided by the AP 110is <NUM>, the Group ID Bitmap Size field <NUM> may have a size of <NUM> bits. In this case, the Group ID Bitmap Size field <NUM> is set to <NUM> to indicate that the Group ID Bitmap Start field <NUM> and the Group ID Bitmap field <NUM> are not present (i.e., no any group ID is assigned by the AP <NUM> to the WUR STA). The Group ID Bitmap Size field <NUM> is set to <NUM>, <NUM>, <NUM> or <NUM> to indicate that the Group ID Bitmap field <NUM> contains a <NUM>-bit, <NUM>-bit, <NUM>-bit or <NUM>-bit bitmap. The Group ID Bitmap Start field <NUM> indicates the group ID corresponding to the LSB (i.e., bit <NUM>) of the Group ID Bitmap field <NUM>. The Group ID Bitmap field <NUM>, together with the Group ID Bitmap Start field <NUM>, indicates the remaining group IDs which are assigned by the AP <NUM> to the intended WUR STA. The Smallest Group ID field <NUM> indicates the smallest Group ID that can be provided by the AP <NUM>.

According to the fourth embodiment of the present disclosure, if the intended WUR STA does not support the reception of group ID based multicast WUR Wake-up frames, both the Number of Group IDs field <NUM> and the Group ID Bitmap Size field <NUM> shall be set to <NUM>.

According to the fourth embodiment of the present disclosure, when bit Y in the Group ID Bitmap field <NUM> is set to <NUM> (Y = <NUM>,<NUM>,. , L-<NUM> and L is the size of the Group ID Bitmap field <NUM>), if the group ID indicated in the Group ID Bitmap Start field <NUM> plus Y is larger than the largest group ID that can be provided by the AP <NUM>, the corresponding group ID equals to the group ID indicated in the Group ID Bitmap Start field <NUM> plus Y minus the number of group IDs that can be provided by the AP <NUM>; Otherwise the corresponding group ID equals to the group ID indicated in the Group ID Bitmap Start field <NUM> plus Y. Notice that the largest group ID that can be provided by the AP <NUM> is equal to the smallest group ID that can be provided by the AP <NUM> and indicated in the Smallest Group ID field 1812plus the number of group IDs that can be provided by the AP <NUM> minus <NUM>.

According to the fourth embodiment of the present disclosure, the smallest group ID that can be provided by the AP <NUM> may be indicated in the Smallest Group ID field <NUM> in the WUR Operation element <NUM> instead of the Smallest Group ID field <NUM> in the WUR Mode element <NUM> since the smallest group ID that can be provided by the AP <NUM> is a common WUR parameter to all WUR STAs. In this case, a WUR STA is able to know the smallest group ID that can be provided by the AP <NUM> from the most recently received WUR Operation element <NUM>.

According to the fourth embodiment of the present disclosure, instead of indicating the smallest group ID that can be provided by the AP <NUM> in the Smallest Group ID field <NUM> in the WUR Operation element <NUM> or the Smallest Group ID field <NUM> in the WUR Mode element <NUM>, the largest group ID that can be provided by the AP <NUM> may be indicated in the WUR Operation element <NUM> or in the WUR Parameters field <NUM> of the WUR Mode element <NUM> transmitted by the AP <NUM>. If the largest Group ID is indicated in the WUR Operation element <NUM>, a WUR STA is able to know the largest Group ID that can be provided by the AP <NUM> from the most recently received WUR Operation element <NUM>.

According to the fourth embodiment of the present disclosure, after receiving the WUR Mode element <NUM> transmitted by the AP <NUM>, the WUR STA can directly store group ID information based on the Group ID Tuples field <NUM>, the Group ID Bitmap Start field <NUM> and the Group ID Bitmap field <NUM>. In this case, for minimizing the memory requirement for storing group ID information, the AP 110may assign group IDs to the WUR STA in such a manner that as many as assigned group IDs can be indicated by a group ID bitmap contained in the Group ID Bitmap field <NUM> and a group ID contained in the Group ID Bitmap Start field <NUM>. Since it is unnecessary for the WUR STA to reorganize the Group ID List field <NUM> into at least one group ID and a group ID bitmap with size not larger than the group ID bitmap size that it is capable of storing, implementation complexity of the WUR STA is reduced.

According to the fourth embodiment of the present disclosure, the encoding of the Number of Group IDs field <NUM> is 0b0000, the encoding of the Group ID Bitmap Size field <NUM> is 0b010, the encoding of the Group ID Bitmap Start field <NUM> is 0x11F, and the encoding of the Group ID Bitmap field <NUM> is 0xA845. In this example, the signaling overhead for the Group ID List field <NUM> is <NUM> bits. The memory required for storing the group ID information is <NUM> bits. So the fourth embodiment may result in less signaling overhead than the third embodiment. Furthermore, the fourth embodiment may result in less memory requirement for storing the group ID information than the third embodiment.

According to a fifth embodiment of the present disclosure, if the Supported Group IDs field <NUM> of the WUR Capabilities element 300transmitted by the WUR STA is set to a non-zero value and the WUR STA belongs to at least one group of WUR STAs, group IDs shall be assigned by the AP <NUM> to the WUR STA in such a manner that at least one of the following is satisfied:.

By doing so, group IDs assigned by the AP <NUM> to the WUR STA can be indicated in a group ID bitmap which the WUR STA is capable of storing and a group ID corresponding to bit <NUM> of the group ID bitmap. As a result, the WUR STA's memory required for storing group ID information is minimized.

<FIG> illustrates an example format of the Group ID List field <NUM> of the WUR Parameters field <NUM> in the WUR Mode element 524transmitted by the AP <NUM> according to the fifth embodiment of the present disclosure. The Group ID List field <NUM> comprises a Group ID Bitmap Size field <NUM>, a Group ID Bitmap Start field <NUM>, a Group ID Bitmap field 1910and a Smallest Group ID field <NUM>. The Group ID Bitmap Size field 1906indicates the size of the Group ID Bitmap field <NUM>. If the number of group IDs that can be provided by the AP <NUM> is <NUM>, the Group ID Bitmap Size field <NUM> may have a size of <NUM> bits. In this case, the Group ID Bitmap Size field <NUM> is set to <NUM> to indicate that the Group ID Bitmap Start field <NUM> and the Group ID Bitmap field <NUM> are not present (i.e., no group ID is assigned by the AP <NUM> to the WUR STA). The Group ID Bitmap Size field <NUM> is set to <NUM>, <NUM>, <NUM> or <NUM> to indicate that the Group ID Bitmap field <NUM> contains a <NUM>-bit, <NUM>-bit, <NUM>-bit or <NUM>-bit bitmap. The Group ID Bitmap Start field <NUM> indicates the group ID corresponding to the LSB (i.e., bit <NUM>) of the Group ID Bitmap field <NUM>. The Group ID Bitmap field <NUM>, together with the Group ID Bitmap Start field <NUM>, indicates the group IDs which are assigned by the AP <NUM> to the intended WUR STA. The Smallest Group ID field <NUM> indicates the smallest Group ID that can be provided by the AP <NUM>.

According to the fifth embodiment of the present disclosure, if the intended WUR STA does not support the reception of group ID based multicast WUR Wake-up frames, the Group ID Bitmap Size field <NUM> shall be set to <NUM>.

According to the fifth embodiment of the present disclosure, when bit Y in the Group ID Bitmap field <NUM> is set to <NUM> (Y = <NUM>,<NUM>,. , L-<NUM> and L is the size of the Group ID Bitmap field <NUM>), if the group ID indicated in the Group ID Bitmap Start field <NUM> plus Y is larger than the largest group ID that can be provided by the AP <NUM>, the corresponding group ID equals to the group ID indicated in the Group ID Bitmap Start field <NUM> plus Y minus the number of group IDs that can be provided by the AP <NUM>; Otherwise the corresponding group ID equals to the the group ID indicated in the Group ID Bitmap Start field <NUM> plus Y. Notice that the largest group ID that can be provided by the AP <NUM> is equal to the smallest group ID that can be provided by the AP <NUM> plus the number of group IDs that can be provided by the AP <NUM> minus <NUM>.

According to the fifth embodiment of the present disclosure, the smallest group ID that can be provided by the AP <NUM> may be indicated in the Smallest Group ID field <NUM> in the WUR Operation element <NUM> instead of the Smallest Group ID field <NUM> in the WUR Mode element <NUM> since the smallest group ID that can be provided by the AP <NUM> is a common WUR parameter to all WUR STAs. In this case, a WUR STA is able to know the smallest group ID that can be provided by the AP <NUM> from the most recently received WUR Operation element <NUM>.

According to the fifth embodiment of the present disclosure, instead of indicating the smallest group ID that can be provided by the AP <NUM> in the Smallest Group ID field <NUM> in the WUR Operation element <NUM> or the Smallest Group ID field <NUM> in the WUR Mode element <NUM>, the largest group ID that can be provided by the AP <NUM> may be indicated in the WUR Operation element <NUM> or in the WUR Parameters field <NUM> of the WUR Mode element <NUM> transmitted by the AP <NUM>. If the largest Group ID is indicated in the WUR Operation element <NUM>, a WUR STA is able to know the largest Group ID that can be provided by the AP <NUM> from the most recently received WUR Operation element <NUM>.

According to the fifth embodiment of the present disclosure, after receiving the WUR Mode element <NUM> transmitted by the AP <NUM>, the WUR STA can directly store group ID information based on the Group ID Bitmap Start field <NUM> and the Group ID Bitmap <NUM>. Compared with the fourth embodiment, the memory requirement for storing group ID information may be reduced.

Notice that in this example, the difference between the smallest group ID and the largest group ID assigned to the WUR STA is <NUM>, which is larger than the group ID bitmap size that the WUR STA is capable of storing. However, the sum of the difference between the smallest group ID assigned to the WUR STA and the smallest group ID that can be provided by the AP <NUM> and the difference between the largest group ID assigned to the WUR STA and the largest group ID that can be provided by the AP 110is <NUM>, which is smaller than the group ID bitmap size that the WUR STA is capable of storing. According to the fifth embodiment of the present disclosure, the encoding of the Group ID Bitmap Size field <NUM> is 0b010, the encoding of the Group ID Bitmap Start field <NUM> is 0x11F, and the encoding of the Group ID Bitmap field <NUM> is 0xA845. In this example, the signaling overhead for the Group ID List field <NUM> is <NUM> bits. The memory required for storing the group ID information is <NUM> bits. So the fifth embodiment results in less signaling overhead than the fourth embodiment.

According to a sixth embodiment of the present disclosure, if the Supported Group IDs field <NUM> of the WUR Capabilities element 300transmitted by the WUR STA is set to <NUM>, the Group ID List field <NUM> is not present in the WUR Parameters field <NUM> in the WUR Mode element <NUM> transmitted by the AP <NUM>. As a result, signaling overhead for the Group ID List field <NUM> is eliminated for the WUR STA which does not support the reception of group ID based multicast WUR Wake-up frames.

According to a sixth embodiment of the present disclosure, if the Supported Group IDs field <NUM> of the WUR Capabilities element 300transmitted by the WUR STA is set to a non-zero value but the WUR STA does not belong to any group of WUR STAs, the Group ID List field <NUM> is not present in the WUR Parameters field <NUM> in the WUR Mode element 524transmitted by the AP <NUM>. As a result, signaling overhead for the Group ID List field <NUM> is eliminated for the WUR STA which supports the reception of group ID based multicast WUR Wake-up frames but does not belong to any group of WUR STAs.

According to the sixth embodiment of the present disclosure, if the Supported Group IDs field 308of the WUR Capabilities element 300transmitted by the WUR STA is set to a non-zero value and the WUR STA belongs to at least one group of WUR STAs, the Group ID List field <NUM> is present in the WUR Parameters field <NUM> in the WUR Mode element 524transmitted by the AP <NUM>. Moreover, group IDs shall be assigned by the AP <NUM> to the WUR STA in such a manner that at least one of the following is satisfied:.

<FIG> illustrates an example format of the Group ID List field <NUM> of the WUR Parameters field <NUM> in the WUR Mode element 524transmitted by the AP <NUM> according to the sixth embodiment of the present disclosure. The Group ID List field <NUM> comprises a Group ID Bitmap Start field <NUM>, a Group ID Bitmap field 2010and a Smallest Group ID field <NUM>. The Group ID Bitmap Start field 2008indicates the group ID corresponding to the LSB (i.e., bit <NUM>) of the Group ID Bitmap field <NUM>. The Group ID Bitmap field <NUM> indicates the group IDs which are assigned by the AP <NUM> to the intended WUR STA. The size of the Group ID Bitmap field <NUM> is the same as the group ID bitmap size which the WUR STA is capable of storing, as indicated in the Supported Group IDs field <NUM> of the WUR Capabilities element <NUM> transmitted by the WUR STA. For example, if the WUR STA is capable of storing <NUM>-bit group ID bitmap, the size of the Group ID Bitmap field <NUM> is <NUM> bits. The Smallest Group ID field <NUM> indicates the smallest Group ID that can be provided by the AP <NUM>.

According to the sixth embodiment of the present disclosure, compared with the fifth embodiment, the signaling overhead of the Group ID List field 840is reduced for the WUR STA which supports the reception of group ID based multicast WUR Wake-up frames.

According to the sixth embodiment of the present disclosure, when bit Y in the Group ID Bitmap field <NUM> is set to <NUM> (Y = <NUM>,<NUM>,. , L-<NUM> and L is the size of the Group ID Bitmap field <NUM>), if the group ID indicated in the Group ID Bitmap Start field <NUM> plus Y is larger than the largest group ID that can be provided by the AP <NUM>, the corresponding group ID equals to the group ID indicated in the Group ID Bitmap Start field <NUM> plus Y minus the number of group IDs that can be provided by the AP <NUM>; Otherwise the corresponding group ID equals to the the group ID indicated in the Group ID Bitmap Start field <NUM> plus Y. Notice that the largest group ID that can be provided by the AP <NUM> is equal to the smallest group ID that can be provided by the AP <NUM> plus the number of group IDs that can be provided by the AP <NUM> minus <NUM>.

According to the sixth embodiment of the present disclosure, the smallest group ID that can be provided by the AP <NUM> may be indicated in the Smallest Group ID field <NUM> in the WUR Operation element <NUM> instead of the Smallest Group ID field <NUM> in the WUR Mode element <NUM> since the smallest group ID that can be provided by the AP <NUM> is a common WUR parameter to all WUR STAs. In this case, a WUR STA is able to know the smallest group ID that can be provided by the AP <NUM> from the most recently received WUR Operation element <NUM>.

According to the sixth embodiment of the present disclosure, instead of indicating the smallest group ID that can be provided by the AP <NUM> in the Smallest Group ID field <NUM> in the WUR Operation element <NUM> or the Smallest Group ID field <NUM> in the WUR Mode element <NUM>, the largest group ID that can be provided by the AP <NUM> may be indicated in the WUR Operation element <NUM> or in the WUR Parameters field <NUM> of the WUR Mode element <NUM> transmitted by the AP <NUM>. If the largest Group ID is indicated in the WUR Operation element <NUM>, a WUR STA is able to know the largest Group ID that can be provided by the AP <NUM> from the most recently received WUR Operation element <NUM>.

According to the sixth embodiment of the present disclosure, after receiving the WUR Mode element <NUM> transmitted by the AP <NUM>, the WUR STA can directly store group ID information based on the Group ID Bitmap Start field <NUM> and the Group ID Bitmap <NUM>.

Notice that in this example, the difference between the smallest group ID and the largest group ID assigned to the WUR STA is <NUM>, which is larger than the group ID bitmap size that the WUR STA is capable of storing. However, the sum of the difference between the smallest group ID assigned to the WUR STA and the smallest group ID that can be provided by the AP <NUM> and the difference between the largest group ID assigned to the WUR STA and the largest group ID that can be provided by the AP 110is <NUM> which is smaller than the group ID bitmap size that the WUR STA is capable of storing. According to the sixth embodiment of the present disclosure, the encoding of the Group ID Bitmap Start field <NUM> is 0x11F and the encoding of the Group ID Bitmap field <NUM> is 0xA845. In this example, the signaling overhead for the Group ID List field <NUM> is <NUM> bits. The memory required for storing the group ID information is <NUM> bits.

The AP <NUM> may need to reassign Group IDs to one or more groups of WUR STAs to optimize Group ID assignment in order to minimize WUR STAs' memory requirement for storing Group ID information. For example, there are a first group of WUR STAs with Group ID = <NUM> and a second group of WUR STAs with Group ID = <NUM> in the BSS of the AP <NUM>; and WUR STAs in the first and second groups are capable of storing <NUM>-bit Group ID bitmap. A new WUR STA which is capable of storing <NUM>-bit Group ID bitmap has just joined the BSS of the AP <NUM>. The AP <NUM> intends to make the new WUR STA belong to both the first group and the second group. For the purpose of minimizing the new WUR STA's memory requirement for storing Group ID information, the AP <NUM> may initiate a Group ID update procedure to change the Group ID of the second group so that the difference between the Group ID of the first group and the new Group ID of the second group is less than <NUM> (e.g., the new Group ID of the second group is changed to <NUM>). By doing so, the new WUR STA only need to store a single Group ID and a <NUM>-bit Group ID bitmap to store Group ID information.

<FIG> illustrates a first example Group ID update procedure <NUM> according to the present disclosure. The procedure 2100starts at step <NUM>. At step <NUM>, the AP <NUM> transmits a broadcast WUR Wake-up frame to all WUR STAs in WUR Mode. After receiving the broadcast WUR Wake-up frame by its WURx, the PCR of each WUR STA in WUR Mode transits to the awake state. At step <NUM>, the AP <NUM> transmits a broadcast addressed Group ID Update frame to all WUR STAs. After receiving the broadcast addressed Group ID Update frame by its PCR, each WUR STA stores the updated Group ID information. The procedure <NUM> stops at step <NUM>.

<FIG> illustrates a second example Group ID update procedure <NUM> according to the present disclosure. The procedure 2150starts at step <NUM>. At step <NUM>, the AP <NUM> transmits a multicast WUR Wake-up frame to a group of WUR STAs in WUR Mode. After receiving the multicast WUR Wake-up frame by its WURx, the PCR of each WUR STA in WUR Mode belonging to the group transits to the awake state. At step <NUM>, the AP <NUM> transmits a broadcast addressed Group ID Update frame to update the Group ID of the group. After receiving the broadcast addressed Group ID Update frame by its PCR, each WUR STA belonging to the group stores the updated Group ID for the group. The procedure <NUM> stops at step <NUM>.

<FIG> illustrates an example format of the Group ID Update frame <NUM> according to the present disclosure. The Group ID Update frame <NUM> is a WUR Action frame with the WUR Action field <NUM> set to "Group ID Update". The Frame Body field 2220of the Group ID Update frame 2200comprises a Group ID Status Bitmap field 2224and an Updated Group ID Tuples field <NUM>. When bit Y of the Group ID Status Bitmap field <NUM> is set to <NUM> where Y = <NUM>,<NUM>,. , L-<NUM> and L is the size of the Group ID Status Bitmap field <NUM>, the group with Group ID equal to the smallest Group ID that can be provided by the AP <NUM> plus Y has a new Group ID. Otherwise the group with Group ID equal to Y has its Group ID unchanged. The Updated Group ID Tuples field 2226comprises one or more Updated Group ID subfields, each containing a new Group ID for a group whose Group ID has changed.

<FIG> illustrates an example format of WUR PPDU 2300according to the present disclosure. The WUR PPDU <NUM> comprises a legacy preamble <NUM>, a BPSK (binary phase shift keying) Mark field <NUM>, a WUR Sync field <NUM> and a WUR Data field <NUM>. The legacy preamble <NUM> and the BPSK Mark field <NUM> are transmitted with <NUM> bandwidth while the WUR Sync field 2306and the WUR Data field <NUM> are transmitted with a much narrower bandwidth (e.g., <NUM>). The legacy preamble <NUM> and the BPSK Mark field <NUM> assist third party STAs in avoiding unnecessary channel access collision. The WUR Sync field <NUM> aims to be used by WURx to perform time synchronization and packet detection. The WUR Sync field <NUM> is also used to indicate the data rate of the WUR Data field <NUM>. The WUR Data field <NUM> contains a WUR frame (e.g., WUR Beacon frame or WUR Wake-up frame).

<FIG> is a simple block diagram of an example WUR <NUM>. The WUR <NUM> may be the WUR <NUM> in the STA <NUM> or the WUR <NUM> in the STA <NUM> as illustrated in <FIG>. The WUR <NUM> comprises a receiver 2410and a receive signal processing circuitry <NUM>. The receiver <NUM> is responsible for reception of WUR signal, and the receive signal processing circuitry <NUM> is responsible for processing the received WUR signal.

<FIG> is a detailed block diagram of the example WUR <NUM>. The WUR <NUM> further comprises a control circuitry <NUM>, a WUR memory <NUM>, and a WUR TSF timer <NUM> which is drived by a clock oscillator <NUM>. The control circuitry <NUM> is used to control general MAC protocol operations. In particular, the control circuitry <NUM> is used to set the WUR TSF timer <NUM> according to received partial TSF. The receiver <NUM> of the WUR <NUM> comprises a PHY processing circuitry <NUM>, which is responsible for converting WUR PPDUs received through antennas into WUR frames. The receive signal processing circuitry <NUM> of the WUR <NUM> comprises a message processing circuitry <NUM>, which is responsible for processing the received WUR frames under the control of the control circuitry <NUM> and passing the corresponding WUR frame information to the control circuitry <NUM>. For example, the message processing circuitry <NUM> is used to extract the partial TSF from each of the received WUR Beacon frames. The received WUR frames are configured according to the various embodiments of the present disclosure. The WUR memory <NUM> is responsible for storing the WUR parameters (e.g., group ID information) negotiated between the WUR STA (e.g., <NUM> or <NUM>) containing the WUR 2400and the AP <NUM>, especially when the WUR STA operates in WUR Mode Suspend.

The WUR <NUM> may comprise many other components that are not illustrated, for sake of clarity, in <FIG> and <FIG>. Only those components that are most pertinent to the present disclosure are illustrated.

<FIG> is a simple block diagram of an example PCR <NUM> which is capable for transmitting and receiving standard IEEE <NUM> signal. The PCR <NUM> may be the PCR <NUM> in the AP <NUM>, the PCR <NUM> in the STA <NUM> or the PCR <NUM> in the STA <NUM> as illustrated in <FIG>. In particular, the PCR <NUM> in the AP <NUM> is also capable for transmitting WUR signal. The PCR <NUM> comprises a transmission signal generating circuitry <NUM>, a transceiver <NUM> and a receive signal processing circuitry <NUM>. The transmission signal generating circuitry 2510is responsible for generating standard IEEE <NUM> signal and WUR signal if applicable, the transceiver <NUM> is responsible for transmitting the generated standard IEEE <NUM> signal and WUR signal if applicable as well as receiving the standard IEEE <NUM> signal, and the receive signal processing circuitry 2530is responsible for processing the received standard IEEE <NUM> signal.

<FIG> is a detailed block diagram of the example PCR <NUM>. The PCR <NUM> further comprises a control circuitry <NUM> and a PCR TSF timer <NUM> which is drived by a clock oscillator <NUM>. The control circuitry <NUM> is used to control general MAC protocol operation. The transmission signal generating circuitry <NUM> comprises a message generating circuitry <NUM>, which is responsible for generating MAC frames (e.g., Beacon frame, Probe Request/Response frame, Association Request/Response frame, WUR Action frame and WUR frame) under the control of the control circuitry <NUM> according to various embodiments of the present disclosure. The transceiver <NUM> comprises a PHY processing circuitry <NUM>, which is responsible for formulating the generated MAC frames into PPDUs including WUR PPDUs and transmitting them through antennas as well as converting PPDUs excluding WUR PPDUs received through the antennas into MAC frames. The receive signal processing circuitry <NUM> comprises a message processing circuitry <NUM>, which is responsible for processing the received MAC frames (e.g., parsing MAC Header, etc.) under the control of the control circuitry <NUM> and passing the corresponding MAC information to the control circuitry <NUM>.

According to the present disclosure, when the PCR 2500is used in the AP <NUM>, it further comprises a WUR memory <NUM>, which is responsible for storing the WUR parameters negotiated between the WUR STAs (e.g., 130and <NUM>) and the AP <NUM>, especially when the WUR STAs operate in WUR Mode Suspend.

The PCR <NUM> may comprise many other components that are not illustrated, for sake of clarity, in <FIG> and <FIG>. Only those components that are most pertinent to the present disclosure are illustrated.

The present disclosure can be realized by software, hardware, or software in cooperation with hardware. Each functional block used in the description of each embodiment described above can be partly or entirely realized by an LSI such as an integrated circuit, and each process described in the each embodiment may be controlled partly or entirely by the same LSI or a combination of LSIs. The LSI may be individually formed as chips, or one chip may be formed so as to include a part or all of the functional blocks. The LSI may include a data input and output coupled thereto. The LSI here may be referred to as an IC, a system LSI, a super LSI, or an ultra LSI depending on a difference in the degree of integration. However, the technique of implementing an integrated circuit is not limited to the LSI and may be realized by using a dedicated circuit, a general-purpose processor, or a special-purpose processor. In addition, a FPGA (Field Programmable Gate Array) that can be programmed after the manufacture of the LSI or a reconfigurable processor in which the connections and the settings of circuit cells disposed inside the LSI can be reconfigured may be used. The present disclosure can be realized as digital processing or analogue processing, as a result of the advancement of semiconductor technology or other derivative technology.

Should a circuit integration technology replacing LSI appear as a result of advancements in semiconductor technology or other technologies derived from the technology, the functional blocks could be integrated using the future integrated circuit technology. Another possibility is the application of biotechnology and/or the like.

Claim 1:
An access point, AP, (<NUM>) comprising:
a signal generator (<NUM>) adapted to generate a transmission signal (<NUM>) that comprises a data field containing a Wake Up Radio, WUR, Mode Setup frame; and
a transmitter (<NUM>) adapted to transmit, to a station, the generated transmission signal,
characterized in that
a field of a WUR Mode element included in the WUR Mode Setup frame contains information on group Identifiers, IDs, assigned by the AP to the station (<NUM>),
the field comprises a subfield containing a group ID bitmap whose size is equal to the number of group IDs in a group ID value range, in which the AP assigns group IDs to STAs, and,
when bit Y of the group ID bitmap is set to <NUM>, a group ID assigned by the AP to the station is equal to a smallest group ID in the group ID value range plus Y, wherein
Y = <NUM>,<NUM>,...L-<NUM> and L is the size of the group ID bitmap.