HK1187761B - Physical layer power save facility with random offset - Google Patents

Description

Physical layer power saving facility with random offsets

Cross Reference to Related Applications

This patent application claims the rights of U.S. provisional patent application No.61/414,872 (attorney docket No. 110474P1), filed 11/17/2010, the contents of which are hereby incorporated by reference.

Technical Field

Certain aspects of the present disclosure generally relate to wireless communications and, more particularly, to using random offsets to achieve power savings.

Background

To address the problem of increased bandwidth requirements demanded by wireless communication systems, different schemes are being developed to allow multiple user terminals to communicate with a single access point over shared channel resources while achieving high data throughput. Multiple Input Multiple Output (MIMO) technology represents one approach that has recently emerged as a popular technique for next generation communication systems. MIMO technology has been adopted in some emerging wireless communication standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard. IEEE802.11 represents a set of Wireless Local Area Network (WLAN) air interface standards developed by the IEEE802.11 committee for short-range communications (e.g., tens to hundreds of meters).

MIMO wireless systems employing multiple (N)_TMultiple) transmitting antenna and multiple (N)_RMultiple) receive antennas are used for data transmission. From N_TA transmitting antenna and N_RThe MIMO channel formed by multiple receiving antennas can be decomposed into multiple (N)_SOne) spatial stream, where N is for all practical purposes_S≤min{N_T,N_R}. The N is_SEach of the spatial streams corresponds to a dimension. MIMO systems may provide improved performance (e.g., higher throughput and/or higher reliability) if the additional dimensionalities created by the multiple transmit and receive antennas are utilized.

In a wireless network with a single Access Point (AP) and multiple Stations (STAs), parallel transmissions may occur on multiple channels to different stations, both in the uplink and downlink directions. There are a number of challenges stored in such systems.

Disclosure of Invention

Certain aspects of the present disclosure provide a first apparatus for wireless communication. The first device generally includes a processing system and a transmitter. The processing system is generally configured to generate a message including a first value, wherein the first value is generated based on a second value associated with the apparatus and a third value associated with a second apparatus. The transmitter is typically configured to transmit the message to the second apparatus.

Certain aspects of the present disclosure provide a method for wireless communication. The method generally comprises: generating, at a first apparatus, a message comprising a first value, wherein the first value is generated based on a second value associated with the first apparatus and a third value associated with a second apparatus; and sending the message to the second device.

Certain aspects of the present disclosure provide a first apparatus for wireless communication. The first device generally comprises: means for generating a message comprising a first value, wherein the first value is generated based on a second value associated with the first apparatus and a third value associated with a second apparatus; and means for sending the message to the second apparatus.

Certain aspects of the present disclosure provide a computer program product for wireless communication. The computer-program product generally includes a computer-readable medium having instructions executable to: generating, at a first apparatus, a message comprising a first value, wherein the first value is generated based on a second value associated with the first apparatus and a third value associated with a second apparatus; and sending the message to the second device.

Certain aspects of the present disclosure provide an access point. The access point generally comprises: at least one antenna; a processing system configured to generate a message comprising a first value, wherein the first value is generated based on a second value associated with the access point and a third value associated with an apparatus; and a transmitter configured to transmit the message to the apparatus through the at least one antenna.

Certain aspects of the present disclosure provide a first apparatus for wireless communication. The first device generally includes a receiver and a processing system. The receiver is generally configured to receive a message from a second apparatus, wherein the message includes a first value. The processing system is generally configured to: determining a second value generated based on a third value associated with the second apparatus and a fourth value associated with the first apparatus; and determining whether the message is intended for the first apparatus based on the first value and the second value.

Certain aspects of the present disclosure provide a method for wireless communication. The method generally comprises: receiving, at a first apparatus, a message from a second apparatus, wherein the message comprises a first value; determining a second value generated based on a third value associated with the second apparatus and a fourth value associated with the first apparatus; and determining whether the message is intended for the first apparatus based on the first value and the second value.

Certain aspects of the present disclosure provide a first apparatus for wireless communication. The first device generally comprises: means for receiving a message from a second apparatus, wherein the message comprises a first value; means for determining a second value generated based on a third value associated with the second apparatus and a fourth value associated with the first apparatus; and means for determining whether the message is intended for the first apparatus based on the first value and the second value.

Certain aspects of the present disclosure provide a computer program product for wireless communication. The computer-program product generally includes a computer-readable medium having instructions executable to: receiving, at a first apparatus, a message from a second apparatus, wherein the message comprises a first value; determining a second value generated based on a third value associated with the second apparatus and a fourth value associated with the first apparatus; and determining whether the message is intended for the first apparatus based on the first value and the second value.

Certain aspects of the present disclosure provide a wireless node. The wireless node generally comprises: at least one antenna; a receiver configured to receive a message from an apparatus through the at least one antenna, wherein the message includes a first value; and a processing system configured to: determining a second value generated based on a third value associated with the apparatus and a fourth value associated with the wireless node; and determining whether the message is intended for the wireless node based on the first value and the second value.

Certain aspects of the present disclosure provide an apparatus for wireless communication. The apparatus generally includes a processing system and a transmitter. The processing system is generally configured to generate a message comprising a field, wherein the field comprises an indication of a number of null streams, if used in a multi-user transmission scheme, or at least a portion of an Identification (ID) value, if used in a single-user transmission scheme. The transmitter is typically configured to transmit the message.

Certain aspects of the present disclosure provide a method for wireless communication. The method generally comprises: generating a message comprising a field, wherein the field comprises an indication of a number of null streams if used in a multi-user transmission scheme or at least a portion of an ID value if used in a single-user transmission scheme; and sending the message.

Certain aspects of the present disclosure provide an apparatus for wireless communication. The apparatus generally comprises: means for generating a message comprising a field, wherein the field comprises an indication of a number of null streams if used in a multi-user transmission scheme or at least a portion of an ID value if used in a single-user transmission scheme; and means for sending the message.

Certain aspects of the present disclosure provide a computer program product for wireless communication. The computer-program product generally includes a computer-readable medium having instructions executable to: generating a message comprising a field, wherein the field comprises an indication of a number of null streams if used in a multi-user transmission scheme or at least a portion of an ID value if used in a single-user transmission scheme; and sending the message.

Certain aspects of the present disclosure provide a wireless node. The wireless node typically includes at least one antenna; a processing system configured to generate a message comprising a field, wherein the field comprises an indication of a number of null streams if used in a multi-user transmission scheme or at least a portion of an ID value if used in a single-user transmission scheme; and a transmitter configured to transmit the message through the at least one antenna.

Certain aspects of the present disclosure provide an apparatus for wireless communication. The apparatus generally comprises: a receiver configured to receive a message comprising a field, wherein the field comprises an indication of a number of space-time streams if used in a multi-user transmission scheme or at least a portion of an ID value if used in a single-user transmission scheme; and a processing system configured to determine whether the message is intended for the apparatus based on at least the portion of the ID value.

Certain aspects of the present disclosure provide a method for wireless communication. The method generally comprises: receiving, at an apparatus, a message comprising a field, wherein the field comprises an indication of a number of space-time streams if used in a multi-user transmission scheme or at least a portion of an ID value if used in a single-user transmission scheme; and determining whether the message is intended for the apparatus based on at least the portion of the ID value.

Certain aspects of the present disclosure provide an apparatus for wireless communication. The apparatus generally comprises: means for receiving a message comprising a field, wherein the field comprises an indication of a number of space-time streams if used in a multi-user transmission scheme or at least a portion of an ID value if used in a single-user transmission scheme; and means for determining whether the message is intended for the apparatus based on at least the portion of the ID value.

Certain aspects of the present disclosure provide a computer program product for wireless communication. The computer-program product generally includes a computer-readable medium having instructions executable to: receiving, at an apparatus, a message comprising a field, wherein the field comprises an indication of a number of space-time streams if used in a multi-user transmission scheme or at least a portion of an ID value if used in a single-user transmission scheme; and determining whether the message is intended for the apparatus based on at least the portion of the ID value.

Certain aspects of the present disclosure provide a wireless node. The wireless node generally comprises: at least one antenna; a receiver configured to receive, through the at least one antenna, a message comprising a field, wherein the field comprises an indication of a number of space-time streams if used in a multi-user transmission scheme or at least a portion of an ID value if used in a single-user transmission scheme; and a processing system configured to determine whether the message is intended for the apparatus based on at least the portion of the ID value.

Drawings

So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to aspects, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only certain typical aspects of this disclosure and are therefore not to be considered limiting of its scope, for the description may admit to other equally effective aspects.

Fig. 1 illustrates a diagram of a wireless communication network in accordance with certain aspects of the present disclosure.

Fig. 2 illustrates a block diagram of an example access point and user terminal in accordance with certain aspects of the present disclosure.

Fig. 3 illustrates a block diagram of an example wireless device in accordance with certain aspects of the present disclosure.

Fig. 4A-4C illustrate example packets that may be transmitted in a single-user (SU) or multi-user (MU) transmission scheme, in accordance with certain aspects of the present disclosure.

Fig. 5 illustrates example operations that may be performed by a base station to facilitate power conservation in accordance with certain aspects of the present disclosure.

FIG. 5A illustrates exemplary modules capable of performing the operations illustrated in FIG. 5.

Fig. 6 illustrates example operations that may be performed by an access point for facilitating power savings in accordance with certain aspects of the present disclosure.

FIG. 6A illustrates exemplary modules capable of performing the operations illustrated in FIG. 6.

Fig. 7A is an example bit composition table for a Very High Throughput (VHT) signal a1 (VHT-SIG-a 1) field, according to certain aspects of the present disclosure.

Fig. 7B is an example bit composition table for a Very High Throughput (VHT) signal a2 (VHT-SIG-a 2) field, in accordance with certain aspects of the present disclosure.

Fig. 8 illustrates example operations, from the perspective of an access point, for sending a message based on a value associated with the access point and another value associated with a station in accordance with certain aspects of the present disclosure.

FIG. 8A illustrates exemplary modules capable of performing the operations illustrated in FIG. 8.

Fig. 9 illustrates, from the perspective of an access point, example operations for transmitting a message including an indication or identification value of a number of space-time streams, in accordance with certain aspects of the present disclosure.

FIG. 9A illustrates exemplary modules capable of performing the operations illustrated in FIG. 9.

Fig. 10 illustrates example operations from the perspective of a station for determining whether a received message is intended for the station based on a value associated with an access point and another value associated with the station in accordance with certain aspects of the present disclosure.

FIG. 10A illustrates exemplary modules capable of performing the operations illustrated in FIG. 10.

Fig. 11 illustrates, from the perspective of a station, example operations for determining whether a received message is intended for the station based on at least a portion of an identification value in the received message, in accordance with certain aspects of the present disclosure.

FIG. 11A illustrates exemplary modules capable of performing the operations illustrated in FIG. 11.

Detailed Description

Various aspects of the disclosure are described more fully hereinafter with reference to the accompanying drawings. This disclosure may, however, be embodied in many different forms and should not be construed as limited to any specific structure or function presented throughout this disclosure. Rather, these aspects are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Based on the teachings herein one skilled in the art should appreciate that the scope of the present disclosure is intended to cover any aspect of the disclosure disclosed herein, whether implemented independently of or in combination with any other aspect of the disclosure. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. Moreover, the scope of the present disclosure is intended to cover such an apparatus or method implemented with other structure, functionality, or structure and functionality in addition to or other than the various aspects of the disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of a claim.

The word "exemplary" is used herein to mean "serving as an example, instance, or illustration. Any aspect described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects. Additionally, the term "legacy station" as used herein generally refers to a wireless network node that supports Institute of Electrical and Electronics Engineers (IEEE) 802.11n or earlier revisions to the IEEE802.11 standard.

Although specific aspects are described herein, many variations and combinations of variations of these aspects are within the scope of the present disclosure. Although certain benefits and advantages of the preferred aspects are mentioned, the scope of the present disclosure is not intended to be limited to a particular benefit, use, or purpose. Rather, the various aspects of the disclosure are intended to be broadly applicable to different wireless technologies, system configurations, networks, and transmission protocols, some of which are illustrated by way of example in the figures and in the preferred aspects. The detailed description and drawings are merely illustrative of the disclosure rather than limiting, the scope of the disclosure being defined by the appended claims and equivalents thereof.

Exemplary Wireless communication System

The techniques described herein may be used for various broadband wireless communication systems, including communication systems based on orthogonal multiplexing schemes. Examples of such communication systems include Spatial Division Multiple Access (SDMA) systems, Time Division Multiple Access (TDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, and the like. SDMA systems may exploit different directions to transmit data belonging to multiple user terminals simultaneously. TDMA systems may allow multiple user terminals to share the same frequency channel by dividing the transmission signal into different time slots, each time slot being assigned to a different user terminal. OFDMA systems utilize Orthogonal Frequency Division Multiplexing (OFDM), a modulation technique that divides the overall system bandwidth into multiple orthogonal subcarriers. These subcarriers may also be referred to as tones, bins, etc. With OFDM, each subcarrier can be independently modulated with data. SC-FDMA systems may utilize interleaved FDMA (ifdma) to transmit on subcarriers distributed across the system bandwidth, localized FDMA (lfdma) to transmit on blocks of adjacent subcarriers, or enhanced FDMA (efdma) to transmit on multiple blocks of adjacent subcarriers. Typically, modulation symbols are transmitted in the frequency domain using OFDM and in the time domain using SC-FDMA.

The teachings herein may be incorporated into (e.g., implemented within or performed by) a variety of wired or wireless devices (e.g., nodes). In some aspects, a wireless node implemented in accordance with the teachings herein may comprise an access point or an access terminal.

An access point ("AP") may include, be implemented as, or referred to as a node B, a radio network controller ("RNC"), an evolved node B (enb), a base station controller ("BSC"), a base transceiver station ("BTS"), a base station ("BS"), a transceiver function ("TF"), a wireless router, a wireless transceiver, a basic service set ("BSs"), an extended service set ("ESS"), a wireless base station ("RBS"), or some other terminology.

An access terminal ("AT") may include, be implemented as, or referred to as, a subscriber station, a subscriber unit, a Mobile Station (MS), a remote station, a remote terminal, a User Terminal (UT), a user agent, a user device, User Equipment (UE), a subscriber station, or some other terminology. In some implementations, an access terminal may comprise a cellular telephone, a cordless telephone, a session initiation protocol ("SIP") phone, a wireless local loop ("WLL") station, a personal digital assistant ("PDA"), a handheld device having wireless connection capability, a station ("STA"), or some other suitable processing device connected to a wireless modem. Accordingly, one or more aspects taught herein may be incorporated into a phone (e.g., a cellular phone or smart phone), a computer (e.g., a laptop), a tablet, a portable communication device, a portable computing device (e.g., a personal data assistant), an entertainment device (e.g., a music or video device or a satellite radio), a Global Positioning System (GPS) device, or any other suitable device configured to communicate via a wireless or wired medium. In some aspects, the node is a wireless node. For example, such wireless nodes may provide connectivity to or to a network (e.g., a wide area network such as the internet or a cellular network) via wired or wireless communication links.

Fig. 1 shows a multiple access Multiple Input Multiple Output (MIMO) system 100 with an access point and user terminals. For simplicity, only one access point 110 is shown in fig. 1. In general, an Access Point (AP) is a fixed station that communicates with the user terminals and may also be referred to as a base station or some other terminology. A user terminal may be fixed or mobile and may also be referred to as a mobile station, a Station (STA), a client, a wireless device, or some other terminology. At any given moment, the access point 110 may communicate with one or more user terminals 120 on the downlink and uplink. The downlink (i.e., forward link) is the communication link from the access points to the user terminals, and the uplink (i.e., reverse link) is the communication link from the user terminals to the access points. A user terminal may also communicate point-to-point with another user terminal. A system controller 130 couples to the access points and provides coordination and control for the access points.

Although portions of the disclosure below will describe user terminals 120 capable of communicating via Spatial Division Multiple Access (SDMA), for certain aspects, the user terminals 120 may also include certain user terminals that do not support SDMA. Thus, for these aspects, the AP110 may be configured to communicate with both SDMA and non-SDMA user terminals. This approach may conveniently allow older versions of user terminals ("legacy" stations) to continue to be deployed in the enterprise, which extends their useful life while allowing newer SDMA user terminals to be introduced where deemed appropriate.

System 100 employs multiple transmit antennas and multiple receive antennas for data transmission on the downlink and uplink. The access point 110 is provided with a plurality (N)_apMultiple) antennas and represents Multiple Input (MI) for downlink transmissions and Multiple Output (MO) for uplink transmissions. Selected group (N)_uUser terminals 120 collectively represent multiple outputs for downlink transmissions and multiple inputs for uplink transmissions. In certain cases, N will not be addressed if by some means_uThe data symbol streams for individual user terminals are multiplexed in code, frequency or time, it is desirable to have N_ap≥N_uNot less than 1. N if the data symbol streams can be multiplexed using TDMA techniques, different code channels using CDMA, disjoint sets of subbands using OFDM, etc_uMay be greater than N_ap. Each selected user terminal transmits user-specific data to and/or receives user-specific data from the access point. In general, each selected user terminal may be equipped with one or more antennas (i.e., N)_ut≥1）。N_uThe selected user terminals may have the same or different numbers of antennas.

MIMO system 100 may be a Time Division Duplex (TDD) system or a Frequency Division Duplex (FDD) system. For a TDD system, the downlink and uplink share the same frequency band. For FDD systems, the downlink and uplink use different frequency bands. MIMO system 100 may also utilize single or multiple carriers for transmission. Each user terminal may be equipped with a single antenna (e.g., to keep costs low) or multiple antennas (e.g., where additional costs may be supported). If the user terminals 120 share the same frequency channel by dividing transmission/reception into different time slots, each of which is assigned to a different user terminal 120; then system 100 may also be a TDMA system.

Fig. 2 shows a block diagram of an access point 110 and two user terminals 120m and 120x in a MIMO system 100. The access point 110 is equipped with N_apAnd antennas 224a through 224 ap. The user terminal 120m is provided withN_ut,mAntennas 252ma through 252mu, and user terminal 120x is equipped with N_ut,xAnd antennas 252xa through 252 xu. The access point 110 is a transmitting entity for the downlink and a receiving entity for the uplink. Each user terminal 120 is a transmitting entity for the uplink and a receiving entity for the downlink. As used herein, a "transmitting entity" is an independently operated device or apparatus capable of transmitting data over a wireless channel, and a "receiving entity" is an independently operated device or apparatus capable of receiving data over a wireless channel. In the following description, the subscript "dn" denotes the downlink, the subscript "up" denotes the uplink, N is chosen_upMultiple user terminals for simultaneous transmission on the uplink, selecting N_dnFor simultaneous transmission on the downlink, N_upMay or may not be equal to N_dnAnd N is_upAnd N_dnMay be a static value or may vary for each scheduling interval. Beam steering or some other spatial processing technique may be used at the access point and the user terminal.

On the uplink, at each user terminal 120 selected for uplink transmission, a TX data processor 288 receives traffic data from a data source 286 and control data from a controller 280. TX data processor 288 applies traffic data for the user terminal d based on the coding and modulation scheme associated with the rate selected for the user terminal_up,mIs processed (e.g., encoded, interleaved, and modulated) and provides a stream of data symbols s_up,m}. TX spatial processor 290 processes the data symbol stream s_up,mPerforms spatial processing on, and is N_ut,mOne antenna provides N_ut,mA stream of transmit symbols. Each transmitter unit (TMTR) 254 receives and processes (e.g., converts to analog, amplifies, filters, and frequency upconverts) a respective transmit symbol stream to generate an uplink signal. N is a radical of_ut,mA transmitter unit 254 providing N_ut,mFor uplink signals from N_ut,mAnd an antenna 252 to the access point 110.

Can be used for a plurality of (N)_upSubscriber terminalScheduling is performed to transmit simultaneously on the uplink. Each of these user terminals performs spatial processing on its data symbol stream and transmits its set of transmit symbol streams on the uplink to the access point.

At access point 110, N_apMultiple antennas 224a through 224ap from all N transmitting on the uplink_upEach user terminal receives an uplink signal. Each antenna 224 provides a received signal to a respective receiver unit (RCVR) 222. Each receiver unit 222 performs a process complementary to that performed by transmitter unit 254 and provides a received symbol stream. RX spatial processor 240 is in a band from N_apN of receiver units 222_apPerforming receiver spatial processing on the received symbol streams and providing N_upA stream of recovered uplink data symbols. Receiver spatial processing is performed in accordance with Channel Correlation Matrix Inversion (CCMI), Minimum Mean Square Error (MMSE), Successive Interference Cancellation (SIC), or some other technique. Each recovered uplink data symbol stream s_up,mIs for a stream of data symbols s transmitted by a respective user terminal_up,mAnd (4) estimating. The RX data processor 242 bases on the stream s of uplink data symbols for each recovery_up,mThe rate used processes the stream to obtain decoded data. The decoded data for each user terminal may be provided to a data sink 244 for storage and/or controller 230 for further processing.

On the downlink, at access point 110, TX data processor 210 receives data from N scheduled for downlink transmission_dnTraffic data from data source 208 for individual user terminals, control data from controller 230, and possibly other data from scheduler 234. Various types of data may be transmitted on different transport channels. TX data processor 210 processes (e.g., encodes, interleaves, and modulates) the traffic data for each user terminal based on a rate selected for that user terminal. TX data processor 210 provides a signal for N_dnN of individual user terminals_dnA stream of downlink data symbols. TX spatial processor 220 pairN_dnPerforms spatial processing for one downlink data symbol stream and N_apOne antenna provides N_apA stream of transmit symbols. Each transmitter unit (TMTR) 222 receives and processes a respective transmit symbol stream to generate a downlink signal. N is a radical of_apA transmitter unit 222 is provided for transmitting data from N_apN for transmission from antenna 224 to user terminal_apA downlink signal.

At each user terminal 120, N_ut,mAntenna 252 receives N from access point 110_apA downlink signal. Each receiver unit (RCVR) 254 processes a received signal from an associated antenna 252 and provides a received symbol stream. RX spatial processor 260 on the data from N_ut,mN of one receiver unit 254_ut,mPerforms receiver spatial processing on the received symbol streams and provides a recovered downlink data symbol stream s for the user terminal_dn,m}. Receiver spatial processing is performed in accordance with CCMI, MMSE, or some other technique. An RX data processor 270 processes (e.g., demodulates, deinterleaves, and decodes) the recovered downlink data symbol stream to obtain decoded data for the user terminal.

At each user terminal 120, a channel estimator 278 estimates the downlink channel response and provides downlink channel estimates, which may include channel gain estimates, SNR estimates, noise variance, etc. Similarly, channel estimator 228 estimates the uplink channel response and provides an uplink channel estimate. Typically, the controller 280 for each user terminal is based on the downlink channel response matrix H for that user terminal_dn,mTo derive a spatial filtering matrix for the user terminal. Controller 230 bases on the effective uplink channel response matrix H_up,effTo derive a spatial filter matrix for the access point. The controller 280 for each user terminal may send feedback information (e.g., downlink and/or uplink eigenvectors, eigenvalues, SNR estimates, etc.) to the access point. Controller 230 and controller 280 also control the operation of various processing units at access point 110 and user terminal 120, respectively.

Fig. 3 illustrates various components that may be used in a wireless device 302, where the wireless device 302 may be used in a wireless communication system, such as the MIMO system 100. The wireless device 302 is an example of a device that may be configured to implement the various methods described herein. The wireless device 302 may be an access point 110 or a user terminal 120.

The wireless device 302 may include a processor 304 that controls the operation of the wireless device 302. The processor 304 may also be referred to as a Central Processing Unit (CPU). Memory 306, which may include both read-only memory (ROM) and Random Access Memory (RAM), provides instructions and data to the processor 304. A portion of memory 306 may also include non-volatile random access memory (NVRAM). Typically, the processor 304 performs logical and arithmetic operations based on program instructions stored in the processor 306. The instructions in the memory 306 may be executable to implement the methods described herein.

The wireless device 302 may also include a housing 308, and the housing 308 may include a transmitter 310 and a receiver 312 to allow transmission and reception of data between the wireless device 302 and a remote location. The transmitter 310 and receiver 312 may be combined into a transceiver 314. A single or multiple transmit antennas 316 may be attached to the housing 308 and electronically coupled to the transceiver 314. The wireless device 302 may also include (not shown) multiple transmitters, multiple receivers, and multiple transceivers.

The wireless device 302 may also include a signal detector 318, and the signal detector 318 may be used to attempt to detect and quantify the level of signals received by the transceiver 314. The signal detector 318 may detect these signals as total energy, energy per subcarrier per symbol, power spectral density, and other signals. The wireless device 302 may also include a Digital Signal Processor (DSP) 320 for use in processing signals.

The various components of the wireless device 302 may be coupled together by a bus system 322, where the bus system 322 may include a power bus, a control signal bus, and a status signal bus in addition to a data bus.

System 100 shown in fig. 1 may operate in accordance with the ieee802.11ac wireless communication standard. IEEE802.11ac stands for IEEE802.11 revision that allows higher throughput in IEEE802.11 wireless networks. This higher throughput may be achieved by several measures, such as concurrent transmission to multiple Stations (STAs) simultaneously, or by using a wider channel bandwidth (e.g., 80MHz or 160 MHz). The ieee802.11ac standard is also referred to as the Very High Throughput (VHT) wireless communication standard.

Physical layer power saving facility

Certain aspects of the present disclosure propose a method for sending information in unused fields of a physical layer header to improve system performance. The proposed method sends part of the Basic Service Set Identifier (BSSID) of the access point during single-user transmission in a header field that is typically used to indicate the number of space-time streams (Nsts).

The ieee802.11ac standard, which is also referred to as Very High Throughput (VHT), supports high throughput operation of a network achieved by several measures, such as parallel transmission to multiple Stations (STAs) simultaneously, or by using a wider channel bandwidth, such as 80MHz or 160 MHz.

The 802.11ac Physical (PHY) header format may contain a field named "number of space time streams (Nsts)" field. The Nsts field may be needed for multi-user (MU) transmissions, but may be partially unused for single-user (SU) transmissions. For example, bits 13-21 (9 bits) of the Nsts field may be unused. These 9 bits of the Nsts field may be used to signal a partial Association Identifier (AID) so that a Station (STA) having a different partial AID may stop receiving a packet after receiving a partial AID different from its own AID.

The access point does not assign an AID to itself and therefore does not define the value of the 9-bit field that should be transmitted to the AP. Such transmission to the AP is referred to as uplink transmission.

For certain aspects, the unused Nsts field may be populated with a partial Basic Service Set Identifier (BSSID) for uplink Single User (SU) packets and a partial AID for unicast downlink SU packets. The BSSID is the Medium Access Control (MAC) address of the AP, which means that the 9-bit field in the uplink SU transmission contains the first 9 bits of the Medium Access Control (MAC) address of the AP. It should be noted that these 9 bits are merely exemplary.

Fig. 4A-4C illustrate exemplary packets that may be transmitted in a single-user or multi-user transmission scheme in accordance with certain aspects of the present disclosure.

Fig. 4A illustrates an exemplary message format (e.g., packet) that includes a PHY header 402A and a field 404, where the field 404 may be used to transmit a number of space-time streams (N) when used for multi-user transmission_STS) Is indicated.

Fig. 4B shows a message sent using a single-user downlink transmission. The message may include a PHY header 402B and a field 406, where the field 406 has a portion of the AID of the station to which the packet is targeted.

Fig. 4C shows a message sent using single-user uplink transmission. The message may include a PHY header 402C with a field 408, where the field 408 has a portion of the BSSID of the access point to which the message is targeted.

For certain aspects, when assigning AIDs to STAs, an AP may skip AIDs having partial AIDs equal to its partial BSSID (e.g., equal to the 9 Least Significant Bits (LSBs) of its MAC address).

For certain aspects, when assigning AIDs to STAs, an AP may also skip part of the BSSIDs of other APs in its vicinity. These BSSIDs can be obtained by beacons received from surrounding APs.

Using partial AIDs for unicast downlink SU packets can ensure that there will be no collisions in the Basic Service Set (BSS). In other words, each STA may have a unique value pointing to it in the PHY header, allowing all other STAs in the BSS to fall back to sleep for the remaining duration of the packet (up to 510 devices, which equals 512 values of the 9-bit field minus the broadcast partial AID (all 0 s) and the partial BSSID of the AP).

For certain aspects, uplink transmissions do not collide in a BSS, but they may collide with partial AIDs of STAs in other BSSs. However, the probability of such collisions occurring is low. For certain aspects, a STA may request a different AID if it detects a collision with another AP or with a STA in another BSS.

Fig. 5 illustrates example operations 500 that may be performed by a base station to facilitate power conservation in accordance with certain aspects of the disclosure. The operation may begin at 502 with: a station generates a first message comprising a field, wherein the field comprises a portion of a Basic Service Set Identifier (BSSID) if used in a single-user transmission scheme, or an indication of a number of space-time streams if used in a multi-user transmission scheme. At 504, the base station sends a first message to the access point. The base station may also receive a second message comprising a field, wherein the field comprises a portion of an Association Identifier (AID) if the second message was transmitted using a single-user transmission scheme, or an indication of a number of space-time streams if the second message was transmitted using a multi-user transmission scheme.

For certain aspects, the base station may compare the received AID with its AID and discard the second message if the received AID is different from its AID.

Fig. 6 illustrates example operations 600 that may be performed by an access point to facilitate power conservation in accordance with certain aspects of the present disclosure. The operations 600 may begin at 602: an access point assigns one or more AIDs to one or more apparatuses, wherein the one or more AIDs are different from a portion of Basic Service Set Identifiers (BSSIDs) of the apparatuses. At 604, the access point may notify the one or more apparatuses of the assigned AID.

Physical layer power saving facility with random offsets

As described above, the 802.11ac Physical (PHY) header may contain a "number of space time streams (Nsts)" field as part of a VHT signal a (VHT-SIG-a) field. The VHT-SIG-a field carries information for interpreting VHT format packets. The Nsts field may be used for multi-user (MU) transmissions, but may be partially unused for single-user (SU) transmissions. For example, bits 13-21 (9 bits) of the Nsts field may be unused. These 9 bits of the Nsts field may be used to signal a partial Association Identifier (AID) so that a Station (STA) having a different partial AID may stop receiving a packet after receiving a partial AID different from its own AID.

For certain aspects, the AID may be randomly selected by the AP to reduce the probability of partial AID collisions between overlapping BSSs. This random selection may cause an undesirable increase in the Traffic Indication Map (TIM) present in each beacon.

Fig. 7A and 7B are example bit composition tables 700, 750 for the VHT-SIG-a1 field and VHT-SIG-a2 field, respectively, according to certain aspects of the present disclosure. For certain aspects of the disclosure, AID selection may remain sequential and may start from 1. The BSS-specific offset may be added to the (partial) AID before entering the partial AID into the 9-bit field of the PHY header (e.g., bits 13-21 of the Nsts field in table 700). The BSS-specific offset may be randomly selected by the AP and signaled to the associated STA by an association response, or may be communicated to the STA by other means.

In this way, the value in the 9-bit field for downlink transmissions is likely to be different from one BSS to the next, allowing STAs to remain awake only when frames are being sent to them.

Fig. 8 illustrates example operations 800 for sending a message based on a value associated with a first apparatus (e.g., an access point) and another value associated with a second apparatus (e.g., a station) from the perspective of the first apparatus, in accordance with certain aspects of the present disclosure. Operation 800 may begin at 802 with the first apparatus generating a message comprising a first value. The first value may be generated based on a second value associated with the first apparatus and a third value associated with a second apparatus. At 804, the first apparatus may send the message to the second apparatus.

According to certain aspects, the second value may be randomly selected. For certain aspects, the generating may include combining the second value associated with the first apparatus and the third value associated with the second apparatus. The combining may include adding the second value to the third value. For certain aspects, the combining may further include truncating the result of the adding.

For certain aspects, operation 800 may further include the first apparatus sequentially assigning the plurality of values to the plurality of apparatuses. The third value may be one of the plurality of values.

For certain aspects, the first apparatus may provide the second value to the second apparatus (e.g., via an association response). For certain aspects, the first apparatus may provide the third value to the second apparatus. Providing a value to a particular device may include transmitting or signaling the value to the particular device.

Fig. 9 illustrates example operations 900 from the perspective of an apparatus (e.g., an access point) for transmitting a message including an indication of a number of space-time streams or an identification value in accordance with certain aspects of the present disclosure. Operation 900 may begin at 902 with the apparatus generating a message comprising a field. The field may include an indication of the number of spatial streams if used in a multi-user transmission scheme or at least a portion of an Identification (ID) value if used in a single-user transmission scheme. At 904, the apparatus may transmit the message.

Fig. 10 illustrates exemplary operations 1000, from the perspective of a first apparatus (e.g., a station), for determining whether a received message is intended for the first apparatus based on a value associated with the first apparatus and another value associated with a second apparatus (e.g., an access point), in accordance with certain aspects of the present disclosure. Operation 1000 may begin at 1002 with the first apparatus receiving a message from a second apparatus. The message may include a field, wherein the field includes a first value. At 1004, the first apparatus may determine a second value generated by combining a third value associated with the second apparatus and a fourth value associated with the first apparatus.

At 1006, the first device may determine whether the message is intended for the first device based on the first value and the second value. The message may be determined to be intended for the first apparatus if the first value is equal to the second value. Otherwise, the first device may determine that the message is not intended for the first device if the first value is not equal to the second value. In this case, the first device may terminate processing (e.g., interpreting) the message based on the determination.

For certain aspects, the first apparatus may determine whether the message is intended for the first apparatus in a first mode. The first apparatus may then initiate a second mode in response to determining that the first apparatus is not the intended recipient of the message, wherein the second mode has lower power consumption than the first mode. For example, the first mode may be an awake mode and the second mode is a sleep mode.

According to certain aspects, operation 1000 may also include the first apparatus receiving an indication of a fourth value associated with the first apparatus. The fourth value associated with the first apparatus may be one of a plurality of values sequentially assigned to a plurality of apparatuses. For certain aspects, at least a portion of the second value may include a plurality of Least Significant Bits (LSBs) of a fourth value associated with the first apparatus.

For certain aspects, operation 1000 may also include the first apparatus receiving an indication of a third value associated with the second apparatus. The first apparatus may receive the indication through an association response.

Fig. 11 illustrates exemplary operations 1100 for determining whether a received message is intended for a station (e.g., a station) based on at least a portion of an identification value in the received message, from the perspective of the apparatus, in accordance with certain aspects of the present disclosure. The operations may begin, at 1102, with the apparatus receiving a message comprising a field. The field may include an indication of a number of space-time streams if used in a multi-user transmission scheme or at least a portion of an Identification (ID) value if used in a single-user transmission scheme. At 1104, the apparatus may determine whether the message is intended for the apparatus based on at least the portion of the ID value.

The various operations of the methods described above may be performed by any suitable module capable of performing the corresponding functions. These modules may include various hardware and/or software components and/or modules, including but not limited to: a circuit, an Application Specific Integrated Circuit (ASIC), or a processor. Generally, where there are operations illustrated in the figures, these operations may have similarly numbered corresponding paired functional module components. For example, the operations 800 illustrated in fig. 8 correspond to the modules 800A illustrated in fig. 8A.

For example, the means for transmitting, the means for signaling, or the means for providing may include a transmitter, such as transmitter unit 222 of access point 110 shown in fig. 2, transmitter unit 254 of user terminal 120 described in fig. 2, or transmitter 310 of wireless device 302 shown in fig. 3. The means for receiving may comprise a receiver, such as the receiver unit 222 of the access point 110 shown in fig. 2, the receiver unit 254 of the user terminal 120 described in fig. 2, or the receiver 312 of the wireless device 302 shown in fig. 3. The means for generating the message, the means for combining, the means for sequentially allocating, the means for terminating processing, the means for initiating, the means for adding, the means for truncating, the means for determining, and/or the means for processing may comprise a processing system, which may comprise one or more processors, such as TX data processor 210 and/or controller 230 of access point 110, or TX data processor 288 and/or controller 280 of user terminal 120, shown in fig. 2.

The term "determining" as used herein includes a variety of actions, and thus "determining" can include calculating, computing, processing, deriving, investigating, looking up (e.g., looking up in a table, a database or another data structure), ascertaining and the like. Likewise, "determining" can include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), and the like. Likewise, "determining" may include resolving, selecting, establishing, and the like.

As used herein, a phrase referring to "at least one of" a list of items refers to any combination of those items, including a single member. For example, "at least one of a, b, or c" is intended to encompass: a; b; c; a and b; a and c; b and c; and a, b and c.

The various illustrative logical blocks, modules, and circuits described in connection with the disclosure herein may be implemented or performed with a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other Programmable Logic Device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any commercially available processor, controller, microcontroller or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The steps of a method or algorithm described in connection with the disclosure herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. The software modules may reside in any form of storage medium known in the art. Some examples of storage media that may be used include Random Access Memory (RAM), Read Only Memory (ROM), flash memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, and the like. A software module may comprise a single instruction, or many instructions, and may be distributed over several different code segments, among different programs, and across multiple storage media. A storage medium may be coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor.

The methods disclosed herein comprise one or more steps or actions to accomplish the described methods. The method steps and/or actions may be interchanged with one another without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and/or use of specific steps and/or actions may be modified without departing from the scope of the claims.

The functions described may be implemented in hardware, software, firmware, or any combination thereof. An exemplary hardware configuration may include a processing system in the wireless node, as embodied in hardware. The processing system may be implemented with a bus architecture. The bus may include any number of interconnecting buses and bridges depending on the specific application of the processing system and the overall design constraints. A bus may link together various circuits, including a processor, a machine-readable medium, and a bus interface. Among other things, a bus interface may be used to connect a network adapter to a processing system via a bus. The network adapter may be used to implement signal processing functions of the PHY layer. In the case of a user terminal 120 (see fig. 1), a user interface (e.g., keypad, display, mouse, joystick, etc.) may also be connected to the bus. The bus may also link various other circuits such as timing sources, peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further.

The processor may be responsible for managing bus processing and general processing, including the execution of software stored on a machine-readable medium. The processor may be implemented using one or more general-purpose processors and/or special-purpose processors. Examples include microprocessors, microcontrollers, DSP processors, and other circuits capable of executing software. Software should be construed broadly to mean instructions, data, or any combination thereof, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. By way of example, a machine-readable medium may include RAM (random access memory), flash memory, ROM (read only memory), PROM (programmable read only memory), EPROM (erasable programmable read only memory), EEPROM (electrically erasable programmable read only memory), registers, a magnetic disk, an optical disk, a hard drive, or any other suitable storage medium, or any combination thereof. The machine-readable medium may be embodied in a computer program product. The computer program product may include packaging materials.

In a hardware implementation, the machine-readable medium may be part of a processing system that is separate from the processor. However, as those skilled in the art will readily appreciate, the machine-readable medium, or any portion thereof, may be external to the processing system. By way of example, a machine-readable medium may include a transmission line, a carrier wave modulated by data, and/or a computer product separate from the wireless node, all of which may be accessed by a processor through a bus interface. Alternatively or in addition, the machine-readable medium or any portion thereof may be integrated into a processor, such as may be the case with a cache and/or a general register file.

The processing system may be configured as a general purpose processing system having one or more microprocessors providing processor functionality and an external memory providing at least a portion of a machine readable medium, all linked together with other supporting circuitry by an external bus architecture. Alternatively, the processing system may be implemented using an ASIC (application specific integrated circuit) having a processor, a bus interface, a user interface (in the case of an access terminal), support circuitry, and at least a portion of a machine-readable medium integrated into a single chip, or may be implemented using one or more FPGAs (field programmable gate arrays), PLDs (programmable logic devices), controllers, state machines, gated logic, discrete hardware components, or any other suitable circuit or any combination of circuits capable of performing the various functions described throughout this disclosure. Those skilled in the art will recognize how best to implement the described functionality of a processing system depending on the particular application and the overall design constraints imposed on the overall system.

The machine-readable medium may include a plurality of software modules. The software modules include instructions that, when executed by the processor, cause the processing system to perform various functions. The software modules may include a transmitting module and a receiving module. Each software module may reside in a single storage device or be distributed across multiple storage devices. By way of example, a software module may be loaded into RAM from a hard drive when a triggering event occurs. During execution of the software module, the processor may load some instructions into the cache to increase access speed. One or more cache lines may then be loaded into a general register file for execution by the processor. When reference is made hereinafter to the functionality of a software module, it is understood that such functionality is implemented by a processor when executing instructions from the software module.

If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. The storage medium may be any available medium that can be accessed by a computerA medium. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Further, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), or wireless technologies such as Infrared (IR), radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, includes Compact Disc (CD), laser disc, optical disc, Digital Versatile Disc (DVD), floppy disk anddisks, where magnetic disks usually reproduce data magnetically, while optical disks reproduce data optically with lasers. Thus, in certain aspects, computer-readable media may comprise non-transitory computer-readable media (e.g., tangible media). Additionally, for other aspects, the computer-readable medium may comprise a transitory computer-readable medium (e.g., a signal). Combinations of the above should also be included within the scope of computer-readable media.

Accordingly, certain aspects may comprise a computer program product for performing the operations presented herein. For example, such a computer program product may include a computer-readable medium having instructions stored (and/or encoded) thereon, the instructions being executable by one or more processors to implement the operations described herein. For certain aspects, the computer program product may include packaging materials.

Further, it is to be understood that modules and/or other suitable means for performing the methods and techniques described herein may be downloaded and/or otherwise obtained by a user terminal and/or base station, as applicable. For example, such a device may be coupled to a server to facilitate the communication of modules for performing the methods described herein. Alternatively, the various methods described herein can be provided via a memory module (e.g., RAM, ROM, a physical storage medium such as a Compact Disc (CD) or floppy disk, etc.), such that the user terminal and/or base station can obtain the various methods upon coupling or providing the memory module to the device. Further, any other suitable technique for providing the methods and techniques described herein to a device may be utilized.

It is to be understood that the claims are not limited to the precise configuration and components illustrated above. Various modifications, changes, and variations may be made in the arrangement, operation, and details of the methods and apparatus described above without departing from the scope of the claims.

Claims (41)

1. A first apparatus for wireless communication, comprising:

a processing system configured to generate a message comprising a field, wherein the field comprises an indication of a number of space-time streams if used in a multi-user transmission scheme or an identification value if used in a single-user transmission scheme, wherein the identification value is generated based on a basic service set, BSS, specific offset associated with the first apparatus and a partial association identifier, AID, associated with a second apparatus; and

a transmitter configured to transmit the message to the second apparatus.

2. The first apparatus of claim 1, wherein the generating comprises adding the BSS-specific offset associated with the first apparatus and the partial AID.

3. The first apparatus of claim 1, wherein the processing system is further configured to sequentially assign a plurality of values to a plurality of apparatuses, and wherein the partial AID is one of the plurality of values.

4. The first apparatus of claim 1, wherein the BSS-specific offset is randomly selected.

5. The first apparatus of claim 1, wherein the transmitter is further configured to provide the BSS-specific offset to the second apparatus via an association response.

6. The first apparatus of claim 1, wherein the transmitter is further configured to provide the partial AID to the second apparatus.

7. A method for wireless communication, comprising:

generating, at a first apparatus, a message comprising a field, wherein the field comprises an indication of a number of space-time streams if used in a multi-user transmission scheme or an identification value if used in a single-user transmission scheme, wherein the identification value is generated based on a basic service set, BSS, specific offset associated with the first apparatus and a partial association identifier, AID, associated with a second apparatus; and

sending the message to the second device.

8. The method of claim 7, wherein the generating comprises adding the BSS-specific offset associated with the first apparatus and the partial AID.

9. The method of claim 7, further comprising sequentially assigning a plurality of values to a plurality of apparatuses, and wherein the partial AID is one of the plurality of values.

10. The method of claim 7, wherein the BSS-specific offset is randomly selected.

11. The method of claim 7, further comprising providing the BSS-specific offset to the second apparatus by an association response.

12. The method of claim 7, further comprising providing the partial AID to the second apparatus.

13. A first apparatus for wireless communication, comprising:

means for generating a message comprising a field, wherein the field comprises an indication of a number of space-time streams if used in a multi-user transmission scheme or an identification value if used in a single-user transmission scheme, wherein the identification value is generated based on a basic service set, BSS, specific offset associated with the first apparatus and a partial association identifier, AID, associated with a second apparatus; and

means for transmitting the message to the second apparatus.

14. The first apparatus of claim 13, wherein the generating comprises adding the BSS-specific offset associated with the first apparatus and the partial AID.

15. The first apparatus of claim 13, further comprising means for sequentially assigning a plurality of values to a plurality of apparatuses, and wherein the partial AID is one of the plurality of values.

16. The first apparatus of claim 13, wherein the BSS-specific offset is randomly selected.

17. The first apparatus of claim 13, further comprising means for providing the BSS-specific offset to the second apparatus via an association response.

18. The first apparatus of claim 13, further comprising means for providing the partial AID to the second apparatus.

19. An access point, comprising:

at least one antenna;

a processing system configured to generate a message comprising a field, wherein the field comprises an indication of a number of space-time streams if used in a multi-user transmission scheme or an identification value if used in a single-user transmission scheme, wherein the identification value is generated based on a basic service set, BSS, specific offset associated with the access point and a partial association identifier, AID, associated with an apparatus; and

a transmitter configured to transmit the message to the apparatus through the at least one antenna.

20. A first apparatus for wireless communication, comprising:

a receiver configured to receive a message from a second apparatus, wherein the message comprises a first value; and

a processing system configured to:

determining a second value generated based on a Basic Service Set (BSS) -specific offset associated with the second apparatus and a partial Association Identifier (AID) associated with the first apparatus;

determining whether the message is intended for the first apparatus based on the first value and the second value; and

processing the message based on the determining whether the message is intended for the first device.

21. The first apparatus of claim 20, wherein the processing system is configured to:

determining that the message is intended for the first device if the first value is equal to the second value.

22. The first apparatus of claim 20, wherein:

the determining whether the message is intended for the first device comprises: determining that the message is not intended for the first device if the first value is not equal to the second value; and

processing the message based on the determination comprises: based on a determination that the message is not addressed to the first apparatus, terminating processing of the message.

23. The first apparatus of claim 20, wherein the determination of whether the message is intended for the first apparatus occurs in a first mode, and the processing system is configured to:

initiating a second mode if the message is not intended for the first device, wherein the second mode has lower power consumption than the first mode.

24. The first apparatus of claim 20, wherein the receiver is further configured to:

receiving an indication of the partial AID associated with the first apparatus.

25. The first apparatus of claim 20, wherein the receiver is further configured to:

receiving an indication of the BSS-specific offset associated with the second device through an association response.

26. The first apparatus of claim 20, wherein at least a portion of the second value comprises a plurality of Least Significant Bits (LSBs) of the partial AID associated with the first apparatus.

27. A method for wireless communication, comprising:

receiving, at a first apparatus, a message from a second apparatus, wherein the message comprises a first value;

determining a second value generated based on a Basic Service Set (BSS) -specific offset associated with the second apparatus and a partial Association Identifier (AID) associated with the first apparatus;

determining whether the message is intended for the first apparatus based on the first value and the second value; and

processing the message based on the determining whether the message is intended for the first device.

28. The method of claim 27, wherein the message is determined to be intended for the first apparatus if the first value is equal to the second value.

29. The method of claim 27, wherein:

the determining whether the message is intended for the first device comprises: determining that the message is not intended for the first device if the first value is not equal to the second value; and

processing the message based on the determination comprises: based on a determination that the message is not addressed to the first apparatus, terminating processing of the message.

30. The method of claim 27, wherein the determining whether the message is intended for the first apparatus occurs in a first mode, and further comprising:

initiating a second mode if the message is not intended for the first device, wherein the second mode has lower power consumption than the first mode.

31. The method of claim 27, further comprising:

receiving an indication of the partial AID associated with the first apparatus.

32. The method of claim 27, further comprising:

receiving an indication of the BSS-specific offset associated with the second device through an association response.

33. The method of claim 27, wherein at least a portion of the second value comprises a plurality of Least Significant Bits (LSBs) of the partial AID associated with the first apparatus.

34. A first apparatus for wireless communication, comprising:

means for receiving a message from a second apparatus, wherein the message comprises a first value;

means for determining a second value generated based on a Basic Service Set (BSS) -specific offset associated with the second apparatus and a partial Association Identifier (AID) associated with the first apparatus;

means for determining whether the message is intended for the first apparatus based on the first value and the second value; and

means for processing the message based on the determination of whether the message is intended for the first device.

35. The first apparatus of claim 34, wherein the message is determined to be intended for the first apparatus if the first value is equal to the second value.

36. The first apparatus of claim 34, wherein:

the determining whether the message is intended for the first device comprises: determining that the message is not intended for the first device if the first value is not equal to the second value; and

processing the message based on the determination comprises: based on a determination that the message is not addressed to the first apparatus, terminating processing of the message.

37. The first apparatus of claim 34, said determining whether the message is intended for the first apparatus occurs in a first mode, and further comprising:

means for initiating a second mode if the message is not intended for the first apparatus, wherein the second mode has lower power consumption than the first mode.

38. The first apparatus of claim 34, further comprising:

means for receiving an indication of the partial AID associated with the first apparatus.

39. The first apparatus of claim 34, further comprising:

means for receiving an indication of the BSS-specific offset associated with the second apparatus in an association response.

40. The first apparatus of claim 34, wherein at least a portion of the second value comprises a plurality of Least Significant Bits (LSBs) of the partial AID associated with the first apparatus.

41. A wireless node, comprising:

at least one antenna;

a receiver configured to receive a message from an apparatus through the at least one antenna, wherein the message includes a first value; and

a processing system configured to:

determining a second value generated based on a Basic Service Set (BSS) -specific offset associated with the apparatus and a partial Association Identifier (AID) associated with the wireless node;

determining whether the message is intended for the wireless node based on the first value and the second value; and

processing the message based on the determining whether the message is intended for the wireless node.