HK1230359A1 - Legacy-compatible control frames - Google Patents

Description

Compatible legacy control frame

The application is a divisional application of an application with the application date of 28/09/2011, the application number of 201180047712.3 and the name of 'compatible traditional control frame'.

Cross Reference to Related Applications

This application claims the benefit of U.S. provisional patent application serial No.61/388,896(atty. dkt. No.102985p1), filed on 1/10/2010, and is hereby incorporated by reference in its entirety.

Technical Field

Certain aspects of the present disclosure generally relate to wireless communications and, more particularly, to using different Medium Access Control (MAC) addresses in a frame for the same device (e.g., user terminal) to indicate how to process the frame.

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 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 the receiving antennas can be decomposed into N_SA separate channel, N_SThe individual channels are also referred to as spatial channels, where N_S≤{N_T,N_R}。N_SAn independent mailEach channel in a lane 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 user 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

In general, certain aspects of the present disclosure relate to using different Media Access Control (MAC) addresses in a frame for the same device (e.g., user terminal) to indicate how to process (e.g., interpret and parse) the frame. In this manner, frames for IEEE802.11ac can carry information that is not present in legacy frames (e.g., frames according to a revision to the IEEE802.11 standard prior to 802.11ac, such as IEEE802.11a or 802.11 n), but these frames can be interpreted by legacy devices in a legacy manner.

Certain aspects of the present disclosure provide a method for wireless communication. Broadly, the method comprises: receiving, at an apparatus, a first frame comprising an indication of a first MAC address; and parsing the received first frame based on the first MAC address.

Certain aspects of the present disclosure provide an apparatus for wireless communication. In general terms, the apparatus comprises: a receiver configured to receive a first frame comprising an indication of a first MAC address; and a processing system configured to parse the received first frame based on the first MAC address.

Certain aspects of the present disclosure provide an apparatus for wireless communication. In general terms, the apparatus comprises: means for receiving a first frame comprising an indication of a first MAC address; and means for parsing the received first frame based on the first MAC address.

Certain aspects of the present disclosure provide a computer program product for wireless communication. In general, the computer program product includes a computer-readable medium having instructions executable to: receiving, at an apparatus, a frame comprising an indication of a MAC address; and parsing the received frame based on the MAC address.

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 frame via the at least one antenna, the frame comprising an indication of a MAC address; and a processing system configured to parse received frames based on the MAC address.

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. 4 illustrates an example frame structure for wireless communication in accordance with certain aspects of the present disclosure.

Fig. 5A-5C illustrate example frame formats for control and management frames for a Media Access Control (MAC) header in the frame structure of fig. 4, in accordance with certain aspects of the present disclosure.

Fig. 6A illustrates an example MAC address structure in accordance with certain aspects of the present disclosure.

Fig. 6B illustrates an exemplary MAC address in a representative form, where the Least Significant Bit (LSB) of each byte is sent first, in accordance with certain aspects of the present disclosure.

Fig. 7 illustrates example operations for processing a received frame based on a MAC address of the frame from the perspective of a receiving entity, in accordance with certain aspects of the present disclosure.

FIG. 7A illustrates exemplary modules for performing the operations shown in FIG. 7.

Fig. 8-11 illustrate example frame exchanges between two wireless devices using legacy-compatible control frames, in accordance with certain aspects of the present disclosure.

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.

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 Station (STA), 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 tablet, 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 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. An access point is generally 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 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 AP 110 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 utilize multiple transmit antennas and multiple receive antennas for data transmission on the downlink and uplink. The access point 110 is equipped with N_apMultiple antennas and represents Multiple Input (MI) for downlink transmission and Multiple Output (MO) for uplink transmission. The selected set of K user terminals 120 collectively represents multiple-output for downlink transmissions and multiple-input for uplink transmissions. For pure SDMA, if the data symbol streams for K user terminals are not multiplexed in code, frequency, or time by some means, then N is desired_apK is more than or equal to 1. K may be greater than N if the data symbol streams may be multiplexed using TDMA techniques, different code channels using CDMA, disjoint sets of subbands using OFDM, and so on_ap. Each user terminal selected transmits user-specific data to and/or receives user-specific data from the access point. In general, each user terminal selected may be equipped with one or more antennas (i.e., N)_utNot less than 1). The selected K user terminals may have the same or different number of antennas.

An SDMA system 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_tAnd antennas 224a through 224 t. User terminal 120m is equipped with N_ut,mAntennas 252ma through 252mu, and user terminal 120x is equipped with N_ut,xAnd antennas 252xa through 252 xu. 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_upEach user terminal to transmit simultaneously on the uplink, selecting N_dnWith 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 can 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 processes (e.g., encodes, interleaves, and modulates) the traffic data for the user terminal based on a coding and modulation scheme associated with the rate selected for the user terminal and provides a data symbol stream. TX spatial processor 290 performs spatial processing on the data symbol stream 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,mAn uplink signal to be transmitted from N_ut,mAnd antenna 252 to the access point.

Can be paired with N_upEach user terminal is scheduled 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_apAll N transmitted from antennas 224a through 224ap 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 the inverse of the process performed by transmitter unit 254 and provides a received symbol stream. RX spatial processor 240 pairs data from N_apN of receiver units 222_apPerforming receiver spatial processing on the received symbol streams and providing N_upA recovered uplink data symbol stream. Receiver spatial processing is performed in accordance with Channel Correlation Matrix Inversion (CCMI), Minimum Mean Square Error (MMSE), Soft Interference Cancellation (SIC), or some other technique. Each recovered uplink data symbol stream is an estimate of the data symbol stream transmitted by the corresponding user terminal. The RX data processor 242 processes (e.g., demodulates, deinterleaves, and decodes) each recovered uplink data symbol stream in accordance with the rate used for that stream to obtain decoded data. The decoded data for each user terminal may be provided to a data sink 244 for storage and/or to controller 230 for further processing.

On the downlink, at access point 110, TX data processor 210 schedules N for downlink transmission_dnEach user terminal receives traffic data from a data source 208, control data from a controller 230, and possibly other data from a 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 pairs N_dnPerforms spatial processing (such as precoding or beamforming, as described in this disclosure) on the downlink data symbol streams and for N_apOne antenna provides N_apA stream of transmit symbols. Each transmitter unit 222 is connected toAnd receives and processes the respective transmit symbol streams to generate downlink signals. N is a radical of_apA transmitter unit 222 is provided for transmitting data from N_apN with antennas 224 transmitting to user terminals_apA downlink signal.

At each user terminal 120, N_ut,mAntenna 252 receives N from access point 110_apA downlink signal. Each receiver unit 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,mReceiver spatial processing is performed on the received symbol streams and provides recovered downlink data symbol streams for the user terminals. The 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 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 provides instructions and data to processor 304, where memory 306 may include both read-only memory (ROM) and Random Access Memory (RAM). A portion of the 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 electrically 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 detect and quantify the level of signals received by the transceiver 314. The signal detector 318 may detect such 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.

Exemplary frame Structure

To communicate, an Access Point (AP)110 and a user terminal 120 in a wireless network (e.g., the system 100 shown in fig. 1) may exchange messages according to certain frame structures. Fig. 4 illustrates an example frame structure 400 for wireless communication, in accordance with certain aspects of the present disclosure. Frame structure 400 may include a preamble 401, a Medium Access Control (MAC) header 402, a frame body 404, and a Frame Check Sequence (FCS) 406. Frame structure 400 may be used for control frames, data frames, and management frames according to the IEEE802.11 standard, although the control frame may not include a frame body.

Fig. 4 also shows a generic frame format 408 for the MAC header 402. The generic frame format 408 (which is also the same as the data frame format) may include 30 8-bit bytes (octets), the 30 8-bit bytes being decomposed into the following: 2 8-bit bytes for Frame Control (FC) field 410, 2 8-bit bytes for duration/ID field 412, 6 8-bit bytes for address 1 field 414, 6 8-bit bytes for address 2 field 416, 6 8-bit bytes for address 3 field 418, 2 8-bit bytes for sequence control field 420, and 6 8-bit bytes for address 4 field 422. The 4 address fields 414, 416, 418, 422 may include: a Source Address (SA), a Destination Address (DA), or an additional address (such as a Transmitter Address (TA), a Receiver Address (RA), or a Basic Service Set Identifier (BSSID)) for filtering the multicast frame to allow transparent mobility in IEEE 802.11. These addresses may be MAC addresses of various network devices, such as user terminal 120 or access point 110.

Fig. 5A illustrates an exemplary frame format 500 for a short control frame, such as a Request To Send (RTS) frame. Such a control frame format 500 may include an FC field 410, a duration field 412, an RA field 502, and a TA field 504. As defined herein, RA generally refers to the MAC address to which frames are sent over the wireless medium. The RA may be a single address or a group address. As defined herein, a TA typically points to the MAC address of the station that transmits the frame over the wireless medium.

Fig. 5B illustrates another exemplary frame format 510 for short control frames, such as Clear To Send (CTS) frames or Acknowledgement (ACK) frames. This control frame format 510 is similar to the control frame format 500 in fig. 5A, but it does not have the TA field 504.

Fig. 5C shows a management frame format 520. The management frame format 520 may include a DA field 522, an SA field 524, a BSSID field 526, and a sequence control field 420 in addition to the FC field 410 and the duration field 412.

Fig. 6A illustrates an exemplary MAC address structure 600. The MAC address may include 6 8-bit bytes (48 bits), where the first 3 8-bit bytes may identify the organization issuing the MAC address and are referred to as an Organization Unique Identifier (OUI) 602. The last 3 8-bit bytes 604 are specific to a Network Interface Controller (NIC) and can be distributed by the issuing organization in almost any way, subject to uniqueness constraints.

In the MAC address structure 600, the Least Significant Bit (LSB) of the highest 8-bit byte may be considered an individual/group (I/G) address bit 606. The next LSB of the 8-bit byte can be considered the universal/local management address bit 608.

Fig. 6B shows an exemplary MAC address AC-DE-48-00-00-80 (in hexadecimal) in a typical form, where the LSB in each byte is sent first. With this transmission order, the I/G address bits 606 and the U/L management address bits are the first and second bits, respectively, transmitted in the wireless medium.

Exemplary legacy compatible frame

IEEE802.11ac is a revision of the IEEE802.11 standard to enable higher throughput in 802.11 networks. Higher throughput is achieved by some measures such as using MU-MIMO (multi-user multiple input multiple output) and 80MHz or 160MHz channel bandwidth. IEEE802.11ac is also known as Very High Throughput (VHT).

A new VHT-capable device may use control frames with additional or different VHT-specific information. However, legacy devices (i.e., devices that support earlier revisions to the IEEE802.11 standard, such as 802.11a and 802.11 n) may not be able to interpret certain VHT control frames.

What is needed, therefore, are techniques and apparatus for defining control frames for IEEE802.11ac that can carry information that is not present in legacy control frames, whereas VHT control frames can be interpreted by legacy devices in a legacy manner.

Fig. 7 illustrates example operations 700 for processing a received frame based on a MAC address of the frame from the perspective of a receiving entity (e.g., user terminal 120 or access point 110). At 702, operations 700 may begin by receiving a first frame including an indication of a first MAC address. At 704, the receiving entity may process (e.g., interpret and/or parse) the received frame based on the first MAC address.

Processing the received first frame may include interpreting the first frame as a legacy frame or a Very High Throughput (VHT) frame according to the first MAC address. As used herein, a "legacy frame" generally refers to a frame that conforms to a revision of the IEEE802.11 standard prior to the 802.11ac revision, and a "VHT frame" generally refers to a frame that conforms to the 802.11ac revision (or a subsequent revision) of the IEEE802.11 standard.

For certain aspects, at 706, the receiving entity may receive a second frame including an indication of a second MAC address, wherein the second MAC address is different from the first MAC address. At 708, the receiving entity may process the received second frame based on the second MAC address such that processing of the second frame is different from processing of the first frame. For certain aspects, a receiving entity may receive a management frame that signals a first MAC address (i.e., informs the receiving entity that a frame including an indication of the first MAC address is intended for the receiving entity) such that the receiving entity will know that frames received using the first MAC address are to be processed in a different manner than frames received using a second MAC address.

Certain aspects of the present disclosure include sending a new 802.11 ac-specific control frame to a second MAC address associated with the same device. The frame received with the first MAC address of the device may be processed as a typical legacy frame, for example according to the 802.11a or 802.11n amendment to the IEEE802.11 standard. However, frames received with the second MAC address may be processed according to different rules as defined in 802.11ac (or later revisions to the IEEE802.11 standard).

The second MAC address may be transmitted in an RA field 502 of a control frame, such as a Request To Send (RTS) frame, a Clear To Send (CTS) frame, or an Acknowledgement (ACK) frame. The second MAC address may also be sent in the DA field 522 of the management frame or in one of the address fields (e.g., address 1 field 414 or address 3 field 418) of the data frame.

For certain aspects, the second MAC address may be a second unique global MAC address associated with the device.

For other aspects, the first MAC address and the second MAC address may be nearly identical, e.g., differ by only one or two bits. For example, the second MAC address may be formed by setting an individual/group (I/G) address bit 606 of the first MAC address to 1 such that the second MAC address is a group address version of the first MAC address. In other words, the I/G address bit 606 of the first MAC address is 0. In this way, the first MAC address differs from the second MAC address by only one address bit. As another example, the second MAC address may be formed by setting a universal/local (U/L) management address bit 608 of the first MAC address to 1 such that the second MAC address is a locally managed version of the first MAC address. For certain aspects, these two ideas can be combined. For example, the second MAC address may be formed by setting the I/G address bits 606 of the first MAC address to 1 and the U/L management address bits of the first MAC address to 1 such that the second MAC address is a locally administered group address version of the first MAC address.

For certain aspects, the second MAC address may be formed by toggling the least significant address bits, which means that the device has two global management MAC addresses since the U/L management address bits 608 may not change with this approach. For other aspects, where the first MAC address always has a convention of setting the least significant bit of 0, the second MAC address may be formed by setting the least significant address bit to 1. Alternatively, in the case where the first MAC address always has the convention of having the least significant bit set to 1, the second MAC address may be formed by setting the least significant address bit to 0.

The second MAC address may be formed by inverting predetermined address bits of the first MAC address, in addition to the above-mentioned address bits. For other aspects, in the case of the convention that the predetermined address bits in the first MAC address are always 0, the second MAC address may be formed by setting the predetermined address bits of the first MAC address to 1. Alternatively, in the case of the convention that the predetermined address bits in the first MAC address are always 1, the second MAC address may be formed by setting the predetermined address bits of the first MAC address to 0.

For certain aspects, the second MAC address may be signaled in a management frame. The second MAC address may be included in the management frame as an Information Element (IE). By sending a management frame with a second MAC address, the second MAC address need not be associated with the first MAC address.

In operation, the transmitting entity may send a frame to the second MAC address of the target receiving entity to indicate that additional information is hidden in the frame or that the frame should be parsed or processed in a different manner. A receiving entity may parse or process frames received using the second MAC address differently than frames received using the first MAC address, even though both MAC addresses belong to the receiving entity.

The first MAC address may be an address provided for address resolution purposes (i.e., when the address is needed to use Address Resolution Protocol (ARP)). For certain aspects, the first MAC address may be used with data frames, while the second MAC address may be used with control frames such as RTS frames, CTS frames, or ACK frames. The first MAC address may be used as a Source Address (SA) for any transmission. The second MAC address may be derived from the first MAC address by a defined rule (e.g., setting a predetermined address bit of the first MAC address to 1), or may be explicitly transmitted in a management frame, both as described above.

For certain aspects, the information transmitted in the VHT-specific control frame (e.g., RTS or CTS frame) may include information about a channel on which the control frame is transmitted or information about a channel on which the control frame is received. In an ieee802.11ac network, the basic channel unit is 20MHz wide. Each PPDU (physical layer conversion protocol (PLCP) protocol data unit) may span 20, 40, 80, or 160MHz (i.e., 1, 2, 4, or 8 20MHz channels). For certain aspects, such bandwidth information may be encoded in two or more bits (e.g., two or more LSBs) of a duration field of a MAC header.

Exemplary frame exchanges between STA a and STA B using legacy-compatible frames are shown in fig. 8-11. In these figures, "a 1" represents the first MAC address of STA a, "a 2" represents the second MAC address of STA a, "B1" represents the first MAC address of STA B, and "B2" represents the second MAC address of STA B.

Fig. 8 shows an RTS frame 802 sent by STA a to the second MAC address B2 of STA B as the intended recipient. The RTS frame 802 can include information, such as VHT-specific information, that is not present in a conventional RTS frame. STA B may parse the received RTS frame 802 differently than typical parsing of a conventional RTS frame to extract this information.

In response to receiving the RTS frame 802, STA B may send a CTS frame 804 to the second MAC address of STA a, which is the intended recipient. The CTS frame 804 may also contain information such as VHT-specific information that is not present in a conventional CTS frame.

Upon receiving the CTS frame 804, STA a may transmit a data frame 806 using the first MAC address indicating that the data frame should be parsed by STA B in the same manner as typical parsing of conventional data frames. To acknowledge receipt of the data frame 806, STA B may send an ACK frame 808, such as a Block Acknowledgement (BA), to the first MAC address of STA a, which is the intended recipient.

Fig. 9 shows an RTS frame 802 sent by STA a to STA B's secondary MAC address B2, followed by a CTS frame 902 sent by STA B to STA a's primary MAC address a 1. Unlike the CTS frame 804 of fig. 8, the CTS frame 902 of fig. 9 may include only information present in a conventional CTS frame. This RTS/CTS exchange may be followed by a data/ACK exchange between the first MAC address of STA a and the first MAC address of STA B as described above with respect to fig. 8.

Fig. 10 illustrates the RTS/CTS exchange between the second MAC addresses as described above for fig. 8. It may be that STA a sends a data frame 1002 to the second MAC address of STA B after that, indicating that the data frame includes information not present in the legacy data frame. In response to receiving the data frame 1002, STA B may parse the data frame 1002 to extract data containing new information, and may then send an ACK frame 1004 to the second MAC address of STA a indicating that the ACK frame 1004 contains information not present in a legacy ACK frame.

Fig. 11 illustrates the data/ACK exchange between the second MAC address of STA a and the second MAC address of STA B as described above for fig. 10. In this scenario, no RTS/CTS exchange need be performed prior to the data/ACK exchange.

In an exemplary transmitter scenario, a data frame may be sent to a particular Receiver Address (RA). The MAC layer may determine that the RTS frame should precede the transmission, that the device with the RA is 802.11ac capable, and that 802.11ac specific information will be included in the RTS frame. The MAC layer may form an RTS frame specific to 802.11ac and include a second MAC address of the intended receiver. The second MAC address may be formed by flipping certain bits in the first MAC address of the intended receiver.

In an exemplary receiver scenario, a STA may receive an RTS frame destined for a second MAC address of the STA. The STA may then resolve the received RTS as an 802.11 ac-specific RTS. For example, the RTS frame may contain information about the channel on which the RTS frame is sent.

The various operations of the methods described above may be performed by any suitable module capable of performing the corresponding functions. The module 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, those operations may have corresponding equivalent functional block components using similar numbering. For example, the operations 700 shown in fig. 7 correspond to the modules 700A shown in fig. 7A.

For example, the means for transmitting may comprise 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 processing may comprise a processing system that may include one or more processors, such as RX data processor 270 and/or controller 280 of user terminal 120 shown in fig. 2, or RX data processor 242 and/or controller 230 of access point 110.

As used herein, the term "determining" includes a wide variety of actions. For example, "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 an access terminal 110 (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. A storage media may be any available media that can be accessed by a computer. 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, a computer-readable mediumThe medium may include 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 (12)

1. An apparatus for wireless communication, comprising:

means for processing configured to select a first Media Access Control (MAC) address from at least two MAC addresses, wherein the selected first MAC address indicates how a device is to parse a first frame; and

means for transmitting configured to transmit the first frame via one or more channels, wherein the first frame is a Very High Throughput (VHT) frame including the first MAC address and bandwidth information regarding the one or more channels.

2. The apparatus of claim 1, wherein the means for processing is configured to indicate, via selection of the first MAC address, whether the device is to parse the first frame into a legacy frame or into a VHT frame by interpreting the first frame.

3. The apparatus of claim 1, wherein:

the means for processing is further configured to select a second MAC address from the at least two MAC addresses, wherein the selected second MAC address is different from the first MAC address and the selected second MAC address indicates how the device is to resolve a second frame differently than resolving the first frame; and

the means for transmitting is further configured to transmit the second frame.

4. The apparatus of claim 3, wherein the first MAC address differs from the second MAC address by only one address bit.

5. The apparatus of claim 4, wherein the one address bit comprises an individual/group (I/G) address bit, a universal/local (U/L) management address bit, or a least significant address bit.

6. The apparatus of claim 1, wherein the bandwidth information is indicated by two or more bits of a field in the first frame.

7. A method for wireless communication, comprising:

selecting a first Media Access Control (MAC) address from at least two MAC addresses, wherein the selected first MAC address indicates how a device is to parse a first frame; and

transmitting the first frame via one or more channels, wherein the first frame is a Very High Throughput (VHT) frame including the first MAC address and bandwidth information on the one or more channels.

8. The method of claim 7, further comprising:

indicating, via selection of the first MAC address, that the apparatus is to parse the first frame into a legacy frame or into a VHT frame by interpreting the first frame.

9. The method of claim 7, further comprising:

selecting a second MAC address from the at least two MAC addresses, wherein the selected second MAC address is different from the first MAC address and the selected second MAC address indicates how the device is to resolve a second frame differently than resolving the first frame; and

and transmitting the second frame.

10. The method of claim 9, wherein the first MAC address differs from the second MAC address by only one address bit.

11. The method of claim 10, wherein the one address bit comprises an individual/group (I/G) address bit, a universal/local (U/L) management address bit, or a least significant address bit.

12. The method of claim 7, wherein the bandwidth information is indicated by two or more bits of a field in the first frame.