Patent Publication Number: US-2013235790-A1

Title: Systems and methods for establishing a connection setup through relays

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application No. 61/636,830, entitled “SYSTEMS AND METHODS FOR ESTABLISHING A CONNECTION SETUP THROUGH RELAYS” and filed on Apr. 23, 2012, the entire contents of which disclosure is herewith incorporated by reference. This application additionally claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application No. 61/608,597, entitled “SYSTEMS AND METHODS FOR ESTABLISHING A CONNECTION SETUP THROUGH RELAYS” and filed on Mar. 8, 2012, the entire contents of which disclosure is herewith incorporated by reference. 
    
    
     BACKGROUND 
     1. Field 
     The present application relates generally to wireless communications, and more specifically to systems, methods, and devices for using a relay in a wireless communication network. 
     2. Background 
     In many telecommunication systems, communications networks are used to exchange messages among several interacting spatially-separated devices. Networks may be classified according to geographic scope, which could be, for example, a metropolitan area, a local area, or a personal area. Such networks would be designated respectively as a wide area network (WAN), metropolitan area network (MAN), local area network (LAN), wireless local area network (WLAN), or personal area network (PAN). Networks also differ according to the switching/routing technique used to interconnect the various network nodes and devices (e.g. circuit switching vs. packet switching), the type of physical media employed for transmission (e.g. wired vs. wireless), and the set of communication protocols used (e.g. Internet protocol suite, SONET (Synchronous Optical Networking), Ethernet, etc.). 
     Wireless networks are often preferred when the network elements are mobile and thus have dynamic connectivity needs, or if the network architecture is formed in an ad hoc, rather than fixed, topology. Wireless networks employ intangible physical media in an unguided propagation mode using electromagnetic waves in the radio, microwave, infra-red, optical, etc. frequency bands. Wireless networks advantageously facilitate user mobility and rapid field deployment when compared to fixed wired networks. 
     The devices in a wireless network may transmit/receive information between each other. In some aspects, the devices in the wireless network may have a poor connection and/or may not be able to communicate with each other. Thus, improved systems, methods, and devices for communicating in a wireless network are desired. 
     SUMMARY 
     The systems, methods, and devices of the invention each have several aspects, no single one of which is solely responsible for its desirable attributes. Without limiting the scope of this invention as expressed by the claims which follow, some features will now be discussed briefly. After considering this discussion, and particularly after reading the section entitled “Detailed Description” one will understand how the features of this invention provide advantages that include improved communications between access points and stations in a wireless network. 
     One aspect of this disclosure provides a method for communicating data in a wireless communications network. The method comprises receiving, by a relay, a relay initiator frame. The method further comprises receiving, by the relay, a data frame. The method further comprises transmitting, by the relay, an amplified version of the data frame at a same or substantially same time as a time that the data frame is received if the relay initiator frame is received prior to the data frame. 
     Another aspect of this disclosure provides an apparatus for communicating data in a wireless communications network. The apparatus comprises means for receiving a relay initiator frame. The apparatus further comprises means for receiving a data frame. The apparatus further comprises means for transmitting an amplified version of the data frame at a same or substantially same time as a time that the data frame is received if the relay initiator frame is received prior to the data frame. 
     Another aspect of this disclosure provides a non-transitory computer-readable medium comprising code that, when executed, causes an apparatus to receive a relay initiator frame. The medium further comprises code that, when executed, causes an apparatus to receive a data frame. The medium further comprises code that, when executed, causes an apparatus to transmit an amplified version of the data frame at a same or substantially same time as a time that the data frame is received if the relay initiator frame is received prior to the data frame. 
     Another aspect of this disclosure provides a relay for communicating data in a wireless communications network. The relay comprises a receiver configured to receive a relay initiator frame and a data frame. The relay further comprises a transmitter configured to transmit an amplified version of the data frame at a same or substantially same time as a time that the data frame is received if the relay initiator frame is received prior to the data frame. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows an exemplary wireless communication system in which aspects of the present disclosure may be employed. 
         FIG. 2  shows a functional block diagram of an exemplary wireless device that may be employed within the wireless communication system of  FIG. 1 . 
         FIG. 3A  illustrates a wireless communications system comprising an access point, a station, and a relay. 
         FIG. 3B  illustrates address fields of a data frame transmission between an access point and a relay and a station and the relay. 
         FIG. 3C  illustrates a wireless communications system in which an access point and a station cannot directly communicate. 
         FIG. 3D  illustrates address fields of a management frame transmission between an access point and a relay and a station and the relay. 
         FIG. 4A  illustrates a timing diagram of a wireless communications system including an access point, a station, and a relay. 
         FIG. 4B  illustrates a timing diagram of a wireless communications system including an access point, a station, and a relay. 
         FIG. 5  illustrates a relay initiator frame. 
         FIG. 6  is a flowchart of a process for selecting a relay in the wireless communications system of FIGS.  1  and  3 A-D. 
         FIG. 7  is a functional block diagram of an exemplary device that may be employed within the wireless communication system of FIGS.  1  and  3 A-D. 
         FIG. 8  is a flowchart of a process for selecting a relay in the wireless communications system of FIGS.  1  and  3 A-D. 
         FIG. 9  is another functional block diagram of an exemplary device that may be employed within the wireless communication system of FIGS.  1  and  3 A-D. 
         FIG. 10  is a flowchart of a process for registering a relay in the wireless communications system of FIGS.  1  and  3 A-D. 
         FIG. 11  is another functional block diagram of an exemplary device that may be employed within the wireless communication system of FIGS.  1  and  3 A-D. 
         FIG. 12  is a flowchart of a process for discovering a wireless communications system of FIGS.  1  and  3 A-D. 
         FIG. 13  is another functional block diagram of an exemplary device that may be employed within the wireless communication system of FIGS.  1  and  3 A-D. 
         FIG. 14  is a flowchart of a process for selecting a relay in the wireless communications system of FIGS.  1  and  3 A-D. 
         FIG. 15  is another functional block diagram of exemplary devices that may be employed within the wireless communication system of FIGS.  1  and  3 A-D. 
         FIG. 16  is a flowchart of a process for selecting a relay in the wireless communications system of FIGS.  1  and  3 A-D. 
         FIG. 17  is another functional block diagram of exemplary devices that may be employed within the wireless communication system of FIGS.  1  and  3 A-D. 
         FIG. 18  is a flowchart of a process for communicating using an amplify and forward relay in the wireless communications system of FIGS.  1  and  3 A-D. 
         FIG. 19  is another functional block diagram of an exemplary device that may be employed within the wireless communication system of FIGS.  1  and  3 A-D. 
         FIG. 20  is a flowchart of a process for setting up an amplify and forward relay in the wireless communications system of FIGS.  1  and  3 A-D. 
         FIG. 21  is another functional block diagram of an exemplary device that may be employed within the wireless communication system of FIGS.  1  and  3 A-D. 
         FIG. 22  illustrates a link identifier element. 
         FIG. 23  illustrates a tunneled encrypted data frame. 
         FIG. 24  illustrates another wireless communications system. 
         FIG. 25  illustrates a messaging timeline for frames that may transmitted in the wireless communications system of  FIG. 24 . 
         FIG. 26  illustrates another messaging timeline for frames that may transmitted in the wireless communications system of  FIG. 24 . 
         FIG. 27  is a flowchart of a process for securely communication data in the wireless communications system of  FIGS. 1 ,  3 A-D, and  24 . 
         FIG. 28  is a functional block diagram of an exemplary device that may be employed within the wireless communication system of  FIGS. 1 ,  3 A-D, and  24 . 
     
    
    
     DETAILED DESCRIPTION 
     Various aspects of the novel systems, apparatuses, and methods 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 disclosure is intended to cover any aspect of the novel systems, apparatuses, and methods disclosed herein, whether implemented independently of, or combined with, any other aspect of the invention. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, the scope of the invention is intended to cover such an apparatus or method which is practiced using other structure, functionality, or structure and functionality in addition to or other than the various aspects of the invention set forth herein. It should be understood that any aspect disclosed herein may be embodied by one or more elements of a claim. 
     Although particular aspects are described herein, many variations and permutations of these aspects fall within the scope of the disclosure. Although some benefits and advantages of the preferred aspects are mentioned, the scope of the disclosure is not intended to be limited to particular benefits, uses, or objectives. Rather, 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 following description of 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. 
     Popular wireless network technologies may include various types of wireless local area networks (WLANs). A WLAN may be used to interconnect nearby devices together, employing widely used networking protocols. The various aspects described herein may apply to any communication standard, such as a wireless protocol. 
     In some aspects, wireless signals in a sub-gigahertz band may be transmitted according to the 802.11ah protocol using orthogonal frequency-division multiplexing (OFDM), direct-sequence spread spectrum (DSSS) communications, a combination of OFDM and DSSS communications, or other schemes. Implementations of the 802.11ah protocol may be used for sensors, metering, and smart grid networks. Advantageously, aspects of certain devices implementing the 802.11ah protocol may consume less power than devices implementing other wireless protocols, and/or may be used to transmit wireless signals across a relatively long range, for example about one kilometer or longer. 
     In some implementations, a WLAN includes various devices which are the components that access the wireless network. For example, there may be two types of devices: access points (“APs”) and clients (also referred to as stations, or “STAs”). In general, an AP may serve as a hub or base station for the WLAN and an STA serves as a user of the WLAN. For example, an STA may be a laptop computer, a personal digital assistant (PDA), a mobile phone, etc. In an example, an STA connects to an AP via a WiFi (e.g., IEEE 802.11 protocol such as 802.11ah) compliant wireless link to obtain general connectivity to the Internet or to other wide area networks. In some implementations an STA may also be used as an AP. 
     An access point (“AP”) may also comprise, be implemented as, or known as a NodeB, Radio Network Controller (“RNC”), eNodeB, Base Station Controller (“BSC”), Base Transceiver Station (“BTS”), Base Station (“BS”), Transceiver Function (“TF”), Radio Router, Radio Transceiver, or some other terminology. 
     A station “STA” may also comprise, be implemented as, or known as an access terminal (“AT”), a subscriber station, a subscriber unit, a mobile station, a remote station, a remote terminal, a user terminal, a user agent, a user device, user equipment, 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, 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 smartphone), a computer (e.g., a laptop), a portable communication device, a headset, 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 gaming device or system, a global positioning system device, or any other suitable device that is configured to communicate via a wireless medium. 
     As discussed above, certain of the devices described herein may implement the 802.11ah standard, for example. Such devices, whether used as an STA or AP or other device, may be used for smart metering or in a smart grid network. Such devices may provide sensor applications or be used in home automation. The devices may instead or in addition be used in a healthcare context, for example for personal healthcare. They may also be used for surveillance, to enable extended-range Internet connectivity (e.g. for use with hotspots), or to implement machine-to-machine communications. 
       FIG. 1  shows an exemplary wireless communication system  100  in which aspects of the present disclosure may be employed. The wireless communication system  100  may operate pursuant to a wireless standard, for example the 802.11ah standard. The wireless communication system  100  may include an AP  104 , which communicates with STAs  106 . 
     A variety of processes and methods may be used for transmissions in the wireless communication system  100  between the AP  104  and the STAs  106 . For example, signals may be sent and received between the AP  104  and the STAs  106  in accordance with OFDM/OFDMA techniques. If this is the case, the wireless communication system  100  may be referred to as an OFDM/OFDMA system. Alternatively, signals may be sent and received between the AP  104  and the STAs  106  in accordance with CDMA techniques. If this is the case, the wireless communication system  100  may be referred to as a CDMA system. 
     A communication link that facilitates transmission from the AP  104  to one or more of the STAs  106  may be referred to as a downlink (DL)  108 , and a communication link that facilitates transmission from one or more of the STAs  106  to the AP  104  may be referred to as an uplink (UL)  110 . Alternatively, a downlink  108  may be referred to as a forward link or a forward channel, and an uplink  110  may be referred to as a reverse link or a reverse channel. 
     The AP  104  may act as a base station and provide wireless communication coverage in a basic service area (BSA)  102 . The AP  104  along with the STAs  106  associated with the AP  104  and that use the AP  104  for communication may be referred to as a basic service set (BSS). It should be noted that the wireless communication system  100  may not have a central AP  104 , but rather may function as a peer-to-peer network between the STAs  106 . Accordingly, the functions of the AP  104  described herein may alternatively be performed by one or more of the STAs  106 . 
     The AP  104  may transmit a beacon signal (or simply a “beacon”), via a communication link such as the downlink  108 , to other nodes STAs  106  of the system  100 , which may help the other nodes STAs  106  to synchronize their timing with the AP  104 , or which may provide other information or functionality. Such beacons may be transmitted periodically. In one aspect, the period between successive transmissions may be referred to as a superframe. Transmission of a beacon may be divided into a number of groups or intervals. In one aspect, the beacon may include, but is not limited to, such information as timestamp information to set a common clock, a peer-to-peer network identifier, a device identifier, capability information, a superframe duration, transmission direction information, reception direction information, a neighbor list, and/or an extended neighbor list, some of which are described in additional detail below. Thus, a beacon may include information both common (e.g. shared) amongst several devices, and information specific to a given device. 
     In some aspects, a STA  106  may be required to associate with the AP  104  in order to send communications to and/or receive communications from the AP  104 . In one aspect, information for associating is included in a beacon broadcast by the AP  104 . To receive such a beacon, the STA  106  may, for example, perform a broad coverage search over a coverage region. A search may also be performed by the STA  106  by sweeping a coverage region in a lighthouse fashion, for example. After receiving the information for associating, the STA  106  may transmit a reference signal, such as an association probe or request, to the AP  104 . In some aspects, the AP  104  may use backhaul services, for example, to communicate with a larger network, such as the Internet or a public switched telephone network (PSTN). 
       FIG. 2  shows an exemplary functional block diagram of a wireless device  202  that may be employed within the wireless communication system  100  of  FIG. 1 . The wireless device  202  is an example of a device that may be configured to implement the various methods described herein. For example, the wireless device  202  may comprise the AP  104 , one of the STAs  106 , or one of the relays  320  and/or  330 . 
     The wireless device  202  may include a processor  204  which controls operation of the wireless device  202 . The processor  204  may also be referred to as a central processing unit (CPU). Memory  206 , which may include both read-only memory (ROM) and random access memory (RAM), may provide instructions and data to the processor  204 . A portion of the memory  206  may also include non-volatile random access memory (NVRAM). The processor  204  typically performs logical and arithmetic operations based on program instructions stored within the memory  206 . The instructions in the memory  206  may be executable to implement the methods described herein. 
     The processor  204  may comprise or be a component of a processing system implemented with one or more processors. The one or more processors may be implemented with any combination of general-purpose microprocessors, microcontrollers, digital signal processors (DSPs), field programmable gate array (FPGAs), programmable logic devices (PLDs), controllers, state machines, gated logic, discrete hardware components, dedicated hardware finite state machines, or any other suitable entities that can perform calculations or other manipulations of information. 
     The processing system may also include machine-readable media for storing software. Software shall be construed broadly to mean any type of instructions, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. Instructions may include code (e.g., in source code format, binary code format, executable code format, or any other suitable format of code). The instructions, when executed by the one or more processors, cause the processing system to perform the various functions described herein. 
     The wireless device  202  may also include a housing  208  that may include a transmitter  210  and/or a receiver  212  to allow transmission and reception of data between the wireless device  202  and a remote location. The transmitter  210  and receiver  212  may be combined into a transceiver  214 . An antenna  216  may be attached to the housing  208  and electrically coupled to the transceiver  214 . The wireless device  202  may also include (not shown) multiple transmitters, multiple receivers, multiple transceivers, and/or multiple antennas. 
     The wireless device  202  may also include a signal detector  218  that may be used in an effort to detect and quantify the level of signals received by the transceiver  214 . The signal detector  218  may detect such signals as total energy, energy per subcarrier per symbol, power spectral density and other signals. The wireless device  202  may also include a digital signal processor (DSP)  220  for use in processing signals. The DSP  220  may be configured to generate a packet for transmission. In some aspects, the packet may comprise a physical layer data unit (PPDU). 
     The wireless device  202  may further comprise a user interface  222  in some aspects. The user interface  222  may comprise a keypad, a microphone, a speaker, and/or a display. The user interface  222  may include any element or component that conveys information to a user of the wireless device  202  and/or receives input from the user. 
     The various components of the wireless device  202  may be coupled together by a bus system  226 . The bus system  226  may include a data bus, for example, as well as a power bus, a control signal bus, and a status signal bus in addition to the data bus. Those of skill in the art will appreciate the components of the wireless device  202  may be coupled together or accept or provide inputs to each other using some other mechanism. 
     Although a number of separate components are illustrated in  FIG. 2 , those of skill in the art will recognize that one or more of the components may be combined or commonly implemented. For example, the processor  204  may be used to implement not only the functionality described above with respect to the processor  204 , but also to implement the functionality described above with respect to the signal detector  218  and/or the DSP  220 . Further, each of the components illustrated in  FIG. 2  may be implemented using a plurality of separate elements. 
     The wireless device  202  may comprise an AP  104 , an STA  106 , a relay  320 , and/or an association relay  330 , and may be used to transmit and/or receive communications. That is, either AP  104 , STA  106 , relay  320 , or association relay  330  may serve as transmitter or receiver devices. Certain aspects contemplate signal detector  218  being used by software running on memory  206  and processor  204  to detect the presence of a transmitter or receiver. 
     In some embodiments, AP  104  and STA  106  may not be able to communicate properly with each other. For example, AP  104  and STA  106  may be able to communicate with each other, but at a lower than desired data rate. In another example, AP  104  and/or STA  106  may be out of a transmit range of the other such that AP  104  and STA  106  cannot communicate with each other. Another device, such as a relay, may be utilized to form a bridge between the AP  104  and the STA  106  such that they can communicate properly with each other. For example, a store and forward relay may receive messages from the AP  104  and/or STA  106 , determine an intended recipient of the messages, and forward the messages to the intended recipient. Store and forward relays may reduce median packet transmit times by half. As another example, an amplify and forward relay may receive messages from the AP  104  and/or STA  106  and immediately retransmit the received messages such that the intended recipient receives the messages. Amplify and forward relays may provide network throughput improvement by allowing for higher modulating and coding schemes (MCS) transmission rates while reducing or avoiding the overhead time associated with transmitting a frame twice. Relays, such as the store and forward relay and the amplify and forward relay, are described in greater detail herein with respect to  FIGS. 3A-17 . 
       FIG. 3A  illustrates a wireless communications system  300  comprising an AP  304 , a STA  306 , and a relay  320 . Note that while only one STA  306  and only one relay  320  are illustrated, the wireless communications system  300  may comprise any number of STAs and relays. In some embodiments, the AP  304  and the STA  306  can communicate with each other via the UL/DL transmission  348 . However, the AP  304  and the STA  306  may have a poor connection. For example, the physical data rate may be limited to the lowest modulation and coding schemes (MCS). In other embodiments, the AP  304  and the STA  306  cannot communicate with each other via the UL/DL transmission  348 . 
     Store and Forward Relays 
     In certain aspects, if the AP  304  and the STA  306  have a poor connection or cannot communicate via the UL/DL transmission  348 , a relay, such as the relay  320 , may be set up to facilitate communication between the AP  304  and the STA  306 . For example, the relay  320  may be a store and forward relay. 
     Before the relay  320  may facilitate communication between the AP  304  and the STA  306 , the relay  320  may register or associate with the AP  304 . During the association, the relay  320  may inform the AP  304  of its capabilities in, for example, a capabilities information field. The capabilities of the relay  320  may include a maximum number of STAs it supports, whether it is a relay for uplink traffic, downlink traffic, or both, or other relevant information for an AP  304  to determine whether it should consider the relay  320  as a suitable relay when it receives a probe request or request for relay connection from a STA. In this way, upon receiving a request for a relay by a STA, the AP can determine the appropriate relays to contact based on the information provided by the relays. 
     In those embodiments in which the AP  304  and the STA  306  have a poor connection, the STA  306  may associate with the AP  304  in any way known in the art. During the association process, the STA  306  may obtain an association identification from the AP  304 . Once the association process is complete, the STA  306  may transmit to the AP  304  a request for relay connection. In an embodiment, the request for relay connection may include the capabilities of the STA  306 . For example, capabilities of the STA  306  may include its transmit range, a maximum and/or a minimum data rate, a type of data the STA  306  transmits, or the like. 
     Once the AP  304  receives the request for relay connection, the AP  304  may instruct one or more relays, such as relay  320  and other relays (not shown), to transmit to the STA  306  a setup response frame. The instructions may include the capabilities of the STA  306  and/or the media access control (MAC) address of the STA  306 . In an embodiment, the setup response frame may be a tunneled direct link setup (TDLS) response frame. Generally, TDLS communications allow for direct communication between STAs in a wireless communications network. The reuse of the TDLS protocol in establishing a connection between a STA and a relay in a wireless communications system may be advantageous since TDLS defines a security protocol, which can be repurposed for securing a link between the relay  320  and the STA  306 . The reuse of the TDLS protocol may also be advantageous because it defines how and when the two communicating entities enter and exit a power saving mode. In this way, the reuse of the TDLS protocol may allow for secure connections and power savings. 
     In an embodiment, the STA  306  may receive one or more setup response frames from one or more relays. The STA  306  may choose one of the relays that it received a setup response frame from to serve as its communications bridge with the AP  304 . For illustration purposes only,  FIG. 3A  depicts STA  306  as choosing relay  320 . The STA  306  may send a setup confirm frame to the chosen relay  320 . In an embodiment, the setup confirm frame may be a TDLS confirm frame. The STA  306  may base the selection on any number of metrics, including the relay&#39;s link quality between itself and the AP  304 , the link quality between the relay and the STA  306 , whether the relay transmits uplink messages, downlink messages, or both, the transmit range of the relay, or the like. 
     In some embodiments, once the STA  306  has transmitted the setup confirm frame, the STA  306  informs the AP  304  about which relay was selected by the STA  306 . Note that the STA  306  may not need to rely on the selected relay  320  to inform the AP  304 , and instead may directly communicate with the AP  304 . In other embodiments, once the STA  306  has transmitted the setup confirm frame, the selected relay  320  informs the AP  304  that it has been selected by the STA  306 . The message informing the AP  304  that the relay  320  has been selected by the STA  302  may include a MAC address of the relay  320 . 
     Note that in order for relay setup to occur, additional messaging may be defined and utilized in the relay setup protocol, as described herein. For example, a new category of action frames may be defined as “Relay Setup.” The category “Relay Setup” may initially include three action fields, where the first action field defines the request for relay connection transmission, the second action field defines the AP  304  instruction for the relays to transmit a setup response frame transmission, and the third action field defines the transmission used to inform the AP  304  that the relay  320  has been selected by the STA  306 . 
     For transmissions  340  from the STA  306  to the relay  320 , the data frames transmitted may contain MAC headers including three address fields. For transmissions  342  from the relay  320  to the STA  306 , the data frames transmitted may contain MAC headers including four address fields. For transmissions  344  from the AP  304  to the relay  320 , the data frames transmitted may contain MAC headers including three address fields. For transmissions  346  from the relay  320  to the AP  304 , the data frames transmitted may contain MAC headers including four address fields. 
       FIG. 3B  illustrates the address fields of the data frame transmissions between the AP  304  and the relay  320  and the STA  306  and the relay  320 . Generally, the first address field  360   a - d  identifies an immediate destination of the packet, the second address field  362   a - d  identifies the immediate originator of the packet, the third address field  364   a - d  identifies the final destination of the packet, and the fourth address field  366   a - d  identifies the initial originator of the packet. For example, transmissions  340  may contain MAC headers including three address fields  360   a ,  362   a , and  364   a . Because the STA  306  is the immediate (and initial) originator of a packet that is immediately intended for the relay  320  and ultimately intended for the AP  304 , address field  360   a  includes an identification of the relay  320 , address field  362   a  includes an identification of the STA  306 , and address field  364   a  includes an identification of AP  304  (e.g., the basic service set identification (BSSID)). Note that in some embodiments, the MAC headers may contain a fourth address field  366   a , but the address field will be empty. In some aspects, the fourth address field may be left empty because the relay  320  is not the final destination of the packet, and by address fields  362   a  and  364   a , the relay  320  is already aware of which STA transmitted the packet and which AP the packet is intended for. 
     Likewise, transmissions  346  may contain MAC headers including four address fields  360   b ,  362   b ,  364   b , and  366   b . In some aspects, transmissions  346  may be thought of as a continuation of transmissions  340 . The relay  320  is the immediate originator of the packet, but the initial originator of the packet is the STA  306 . The packet is immediately and ultimately intended for the AP  304 . Accordingly, address field  360   b  includes an identification of the AP  304 , address field  362   b  includes an identification of the relay  320 , address field  364   b  includes an identification of the AP  304 , and address field  366   b  includes an identification of the STA  306 . 
     Transmissions  344  may contain MAC headers including three address fields  360   c ,  362   c , and  364   c . Because the AP  304  is the immediate (and initial) originator of a packet that is immediately intended for the relay  320  and ultimately intended for the STA  306 , address field  360   c  includes an identification of the relay  320 , address field  362   c  includes an identification of the AP  304 , and address field  364   c  includes an identification of the STA  306 . Like with transmission  340 , in some embodiments, the MAC headers may contain a fourth address field  366   c , but the address field will be empty. In some aspects, the fourth address field may be left empty because the relay  320  is not the final destination of the packet, and by address fields  362   c  and  364   c , the relay  320  is already aware of which AP transmitted the packet and which STA the packet is intended for. 
     Likewise, transmissions  342  may contain MAC headers including four address fields  360   d ,  362   d ,  364   d , and  366   d . In some aspects, transmissions  342  may be thought of as a continuation of transmissions  344 . The relay  320  is the immediate originator of the packet, but the initial originator of the packet is the AP  304 . The packet is immediately and ultimately intended for the STA  306 . Accordingly, address field  360   d  includes an identification of the STA  306 , address field  362   d  includes an identification of the relay  320 , address field  364   d  includes an identification of the STA  306 , and address field  366   d  includes an identification of the AP  304 . 
     In those embodiments in which the AP  304  and the STA  306  cannot communicate with each other, one or more relays may handle the association and network management as well as the data transmission.  FIG. 3C  illustrates a wireless communications system  350  in which the AP  304  and the STA  306  cannot directly communicate. For example, the AP  304  and the STA  306  may not be able to directly communicate because the STA  306  transmit power may be too low to reach the AP  304 . Wireless communications system  350  may include AP  304 , STA  306 , relay  320 , and association relay  330 . Note that in some embodiments, the functionality of relay  320  and association relay  330  described herein may be performed by a single relay. Note also that for the purposes of simplicity, only one STA and only two relays are illustrated in  FIG. 3C . However, wireless communications system  350  may include any number of STAs and relays. 
     The STA  306  may be able to discover the basic service set (BSS) through relays. In some embodiments, a relay, such as association relay  330 , may respond to probe requests (via a probe response frame) transmitted by STAs that are sent to a wildcard service set identifier (SSID) or to the BSSID of the BSS that the association relay  330  operates in. In other embodiments, the association relay  330  may transmit messages to passively scan for STAs. The probe response frames and/or the messages transmitted by the association relay  330  may contain information elements that identify itself as a relay. In addition, the probe response frames and/or the messages may include information regarding the AP  304  that the association relay  330  is associated with (such as the SSID of the AP  304 ) and information regarding the capabilities of the association relay  330 , which may include a link quality (i.e., an air link quality) that the association relay  330  shares with the AP  304 . 
     Note that in some embodiments, the probe request transmitted by STA  306  may include additional parameters that the association relay  330  may use to determine whether to respond to the request. For example, the request may include information on whether the STA  306  wants a response only from an AP  304  or from either an AP  304  or any relays, such as association relay  330 . The request may also include an identification of minimum capabilities desired by the STA  306 , an identification of security parameters desired by the STA  306 , identification of power save modes desired by the STA  306 , and/or an identification of a link quality level (i.e., an air link quality level) that the STA  306  would like between the association relay  330  and the AP  304 . 
     Note also that even if STA  306  cannot communicate with AP  304 , the STA  306  may still be able to receive beacon messages from the AP  304 . The beacon messages from the AP  304  may include information on which, if any, relays are associated with the AP  304 . The beacon messages may further include an address of associated relays and metrics of air link quality. In some embodiments, the STA  306  may use the information in the beacon message transmitted by the AP  304  to determine whether it wants to search for a relay for that particular SSID. For example, the metrics of air link quality may allow the STA  306  to send unicast probe requests directly to a chosen relay(s). The STA  306  may also use the information in the beacon message to decide whether to request a relay via the request for relay connection message, or roam to another AP. 
     Once the BSS has been discovered through the association relay  330 , the STA  306  can begin the process of associating with the AP  304  through the association relay  330 . The association can take place in any way known in the art, but the association relay  330  may serve to bridge the communication between the STA  306  and the AP  304 . In other words, the association relay  330  may receive management frames from the STA  306  and forward those to the AP  304 , and vice versa, so that the STA  306  can associate with the AP  304 . 
     Like the data frames described with respect to  FIG. 3B , the management frames may contain four address fields.  FIG. 3D  illustrates the address fields of the management frame transmissions between the AP  304  and the association relay  330  and the STA  306  and the association relay  330 . The address fields  370   a - d ,  372   a - d ,  374   a - d , and  376   a - d  of the management frames are set in a similar manner as the address fields  360   a - d ,  362   a - d ,  364   a - d , and  366   a - d  of the of the data frames. In this way, the STA  306  can successfully associate with the AP  304  and the AP  304  can identify the exact STA  306  that is attempting to associate with it. 
     Once the association is complete, the association relay  330  can be used to handle the relay selection and the TDLS response and confirm frames as described herein and with respect to  FIGS. 3A-B . In other words, the association relay  330  may serve as a conduit, forwarding messages from the STA  306  to the AP  304  in the relay selection process described herein with respect to  FIGS. 3A-B . For example, the association relay  330  may receive the request for relay connection from the STA  306  and forward this request to the AP  304 . The AP  304  may then instruct other relays associated with the AP  304  to transmit the setup response frame. The STA  306  may then inform the association relay  330  of the relay it selected. The association relay  330  and/or the selected relay  320  may separately inform the AP  304  of which relay the STA  306  selected. 
     Note that in some embodiments, the association relay  330  is not the relay that the STA  306  selects to relay data transmissions. For example, as illustrated in  FIG. 3C , the STA  306  selects relay  320  for data transmissions and communicates with the relay  320  as is described herein with respect to  FIGS. 3A-B . In other embodiments, not shown, the association relay  330  is the relay that the STA  306  selects. Once the association and selection process is complete, the STA  306  communicates with the association relay  330  for data transmissions as is described herein with respect to  FIGS. 3A-B . 
     In alternative embodiments, the management frames may include three address fields. The management frames, however, may include an indication, such as a one bit indication, that indicates when the frame is to be relayed to the AP  304 . For example, the STA  306  may include a high indication when it wants the association relay  330  to forward the frame to the AP  304 . The STA  306  may include a low indication when it does not want the association relay  330  to forward the frame to the AP  304 . 
     Note that in general, if the AP  304  assigns AIDs, then a relayed frame may carry the AID of the STA  306  rather than the full address of the STA  306 . Note also that to reduce the likelihood of collisions, there may be a reserved period of time for relays to accept transmissions from STAs. The reserved period of time may be the same for all relays or different per relay. 
     Amplify and Forward Relays 
     In other aspects of the disclosure, relay  320  may be an amplify and forward relay. As described herein, an amplify and forward relay may reduce overhead because a packet received by the relay  320  would not need to be decrypted once received, and then re-encrypted when the packet is relayed. The amplify and forward relays may be useful when the STA  306  and the AP  304  can communicate with each other directly, albeit poorly, or when the STA  306  can communicate with the AP  304  via another relay, such as a store and forward relay. 
       FIG. 4A  illustrates a timing diagram  400  of a system including the AP  304 , the STA  306 , and the relay  320 , where the relay  320  is an amplify and forward relay and all three devices communicate over a channel. In an embodiment, the AP  304  generates a relay initiator frame (RIF)  402  for transmission to the relay  320 . In general, the RIF  402  may be addressed to a particular relay. As illustrated in  FIG. 4A , the RIF  402  is addressed to the relay  320 . After transmitting the RIF  402 , the AP  304  may wait a duration equal to or nearly equal to a short interframe space (SIFS) before transmitting a data frame  404   a . Receipt of the RIF  402  may cause the relay  320  to transmit an amplified version of any signal it detects on the channel, such as the amplified data frame  404   b  illustrated in  FIG. 4A . The relay  320  may transmit an amplified version of any signal it detects on the channel at a same or substantially same time as the time that the relay  320  receives or detects the signal on the channel. For example, the relay  320  may transmit the amplified data frame  404   b  as a same or substantially same time as the time that the relay  320  receives the data frame  404   a . Note that there may be some time delay between the receiving of data frame  404   a  and the transmitting of amplified data frame  404   b  due to the inherent latency of relay  320 . In an embodiment, the relay  320  may transmit an amplified version of any signal it detects on the channel after waiting a duration equal to or nearly equal to the SIFS following the transmission of the RIF  402 . 
     The STA  306  may receive the amplified data frame  404   b  transmitted by the relay  320 . After waiting a period, such as a SIFS duration, the STA  306  may transmit an acknowledgement  408   a . The relay  320  may receive the acknowledgment  408   a  and transmit an amplified version of the acknowledgment, amplified acknowledgment  408   b . Likewise, if the relay  320  receives any other signals following the RIF  402  and following a SIFS duration, the relay  320  may transmit an amplified version of that signal as well. In an embodiment, a duration from the time the RIF  402  transmission ends to the time the acknowledgment  408   a  and amplified acknowledgment  408   b  transmission ends may be equal to a network allocation vector (NAV) of the RIF  402 . 
     In some embodiments, the relay  320  may concurrently operate a packet detector to detect packets on the channel. If the relay  320  determines that the channel is idle, the relay  320  may cease transmitting, even if a RIF  402  has been received and a SIFS duration has passed. 
     While  FIG. 4A  illustrates the AP  304  transmitting the RIF  402 , this is not meant to be limiting. The relay  320  may also receive a RIF from the STA  306  and perform the same operations as described herein. For example, the relay  320  may receive a RIF from the STA  306  and amplify a data frame transmitted by the STA  306 . Likewise, the relay  320  may amplify an acknowledgment transmitted by the AP  304 . 
       FIG. 4B  illustrates a timing diagram  450  of a system including the AP  304 , the STA  304 , and the relay  320 , where the relay  320  is again an amplify and forward relay and all three devices communicate over a channel. In some embodiments, prior to transmitting the RIF  452 , the AP  304  may transmit a request to send (RTS)  460  message over the channel and addressed to the relay  320 . If the channel is idle or the relay  320  otherwise determines a data transmission is acceptable, the relay  320  may respond by transmitting a clear to send (CTS)  462  message back to the AP  304 . Once the AP  304  receives the CTS  462  message, it may operate as discussed above with respect to  FIG. 4A . 
       FIG. 5  illustrates a RIF frame  500 , such as may be included in RIF  402  of  FIGS. 4A-B . RIF frame  500  may include four fields: frame control (FC)  502 , duration  504 , relay address  506 , and cyclic redundant check (CRC)  508 . As an example, the FC  502  field may be 2 octets in length and may be used as is known in the art. Duration  504  may be 2 octets in length and may be set to the duration that encompasses the data packet transmission and the acknowledgment. Relay address  506  may be set to the address of a relay to which the RIF frame  500  is directed and may be 6 octets in length. The CRC  508  field may be 4 octets in length. 
     Note that in order for relay setup to occur, additional messaging may be defined and utilized in the relay setup protocol, as described herein. For example, as described herein, a new category of action frames may be defined as “Relay Setup” and include three initial action fields. For amplify and forward relays, the category “Relay Setup” may include six additional action fields. The fourth action field may define a request for an amplify and forward relay connection transmitted by the STA  306  to the AP  304 . The fifth action field may define an AP  304  request (such as a discovery request frame) to the amplify and forward relays to transmit a discovery message to the STA  306 . The request may include the address of the STA  306  and may be unicast, broadcast and/or group addressed. The sixth action field may define a discovery message transmitted from the amplify and forward relays to the STA  306 . The discovery message may include a metric of the AP  304  to relay link (i.e., a quality of the air link between the AP  304  and the given amplify and forward relay). Note that the STA  306  may eventually choose an amplify and forward relay based on this metric and the link quality (i.e., air link quality) between itself and the amplify and forward relay. The seventh action field may define a message from the STA  306  to the AP  304  informing the AP  304  of which amplify and forward relay was selected by the STA  306 . The message may include a MAC address of the selected amplify and forward relay. The eight action field may define a message from the STA  306  to the AP  304  informing the AP  304  that the STA  306  will no longer be using the selected relay. The ninth action field may define a message from the selected relay to the AP  304  informing the AP  304  that the STA  306  has been removed from its “relay services” (e.g., the selected relay will no longer be forwarding messages between the AP  304  and the STA  306 ). 
       FIG. 6  is a flowchart of a process  600  for selecting a relay in the wireless communications system of FIGS.  1  and  3 A-D. In an embodiment, the process  600  may be performed by an AP, such as the AP  104  or the AP  304 . At block  602 , the process  600  receives a request for relay connection from a STA. In an embodiment, the STA has associated with the AP. At block  604 , the process  600  transmits a message to at least one relay based on the received request for relay connection. In an embodiment, the message comprises an instruction to transmit a setup response frame to the STA. In a further embodiment, the setup response frame may be a TDLS response frame. In a further embodiment, the STA is configured to select one of the at least one relay based on at least one setup response frame received from at least one of the at least one relay. In a further embodiment, the STA is configured to transmit a setup confirm frame to the selected relay. In a further embodiment, the setup confirm frame is a TDLS confirm frame. In a further embodiment, the STA is configured to transmit information regarding the selected relay to the AP. After block  604 , the process  600  ends. 
       FIG. 7  is a functional block diagram of an exemplary device  700  that may be employed within the wireless communication system  100 ,  300 , and  350 . The device  700  includes means  702  for receiving a request for relay connection from a STA. In an embodiment, means  702  for receiving a request for relay connection from a STA may be configured to perform one or more of the functions discussed above with respect to block  602 . The device  700  further includes means  704  for transmitting a message to at least one relay based on the received request for relay connection. In an embodiment, means  704  for transmitting a message to at least one relay based on the received request for relay connection may be configured to perform one or more of the functions discussed above with respect to block  604 . 
       FIG. 8  is a flowchart of a process  800  for selecting a relay in the wireless communications system of FIGS.  1  and  3 A-D. In an embodiment, the process  800  may be performed by a STA, such as the STA  106  or the STA  306 . At block  802 , the process  800  transmits a request for relay connection to an access point. In an embodiment, the access point is configured to transmit a message to at least one relay in response to the request for relay connection. In a further embodiment, the message comprises an instruction to transmit a setup response frame. At block  804 , the process  800  selects one of the at least one relay based on at least one setup response frame received from at least one of the at least one relay. After block  804 , the process  800  ends. 
       FIG. 9  is another functional block diagram of an exemplary device  900  that may be employed within the wireless communication system  100 ,  300 , and  350 . The device  900  includes means  902  for transmitting a request for relay connection to an access point. In an embodiment, means  902  for transmitting a request for relay connection to an access point may be configured to perform one or more of the functions discussed above with respect to block  802 . The device  900  further includes means  904  for selecting one of the at least one relay based on at least one setup response frame received from at least one of the at least one relay. In an embodiment, means  904  for selecting one of the at least one relay based on at least one setup response frame received from at least one of the at least one relay may be configured to perform one or more of the functions discussed above with respect to block  804 . 
       FIG. 10  is a flowchart of a process  1000  for registering a relay in the wireless communications system of FIGS.  1  and  3 A-D. In an embodiment, the process  1000  may be performed by an AP, such as the AP  104  or the AP  304 . At block  1002 , the process  1000  receives an association message from a device configured to operate as a relay. In an embodiment, the association message comprises capabilities of the device and an indication of whether the device relays uplink traffic, downlink traffic, or both. At block  1004 , the process  1000  associates the device with the AP based on the association message. At block  1006 , the process  1000  transmits a beacon message to a STA. In an embodiment, the beacon message comprises an indication of whether the AP is associated with a relay. After block  1006 , the process  1000  ends. 
       FIG. 11  is a functional block diagram of an exemplary device  1100  that may be employed within the wireless communication system  100 ,  300  and  350 . The device  1100  includes means  1102  for receiving an association message from a device configured to operate as a relay. In an embodiment, means  1102  for receiving an association message from a device configured to operate as a relay may be configured to perform one or more of the functions discussed above with respect to block  1002 . The device  1100  further includes means  1104  for associating the device with the AP based on the association message. In an embodiment, means  1104  for associating the device with the AP based on the association message may be configured to perform one or more of the functions discussed above with respect to block  1004 . The device  1100  further includes means  1106  for transmitting a beacon message to a STA. In an embodiment, means  1106  for transmitting a beacon message to a STA may be configured to perform one or more of the functions discussed above with respect to block  1006 . 
       FIG. 12  is a flowchart of a process  1200  for discovering a wireless communications system of FIGS.  1  and  3 A-D. In an embodiment, the process  1200  may be performed by a STA, such as the STA  106  or the STA  306 . In an embodiment, the process  1200  may be utilized when a STA cannot communicate directly with an AP in order to associate with the AP. At block  1202 , the process  1200  transmits a probe request. In an embodiment, the probe request is addressed to one of a wildcard SSID and a BSSID of a BSS in which a relay operates. At block  1204 , the process  1200  receives a probe response from the relay. In an embodiment, the probe response comprises an identification of an AP the relay is associated with and capabilities of the relay. After block  1204 , the process  1200  ends. 
       FIG. 13  is a functional block diagram of an exemplary device  1300  that may be employed within the wireless communication system  100 ,  300 , and  350 . The device  1300  includes means  1302  for transmitting a probe request. In an embodiment, means  1302  for transmitting a probe request may be configured to perform one or more of the functions discussed above with respect to block  1202 . The device  1300  further includes means  1304  for receiving a probe response from the relay. In an embodiment, means  1304  for receiving a probe response from the relay may be configured to perform one or more of the functions discussed above with respect to block  1204 . 
       FIG. 14  is a flowchart of a process  1400  for selecting a relay in the wireless communications system of FIGS.  1  and  3 A-D. In an embodiment, the process  1400  may be performed by an AP, such as the AP  104  or the AP  304 . In an embodiment, the process  1400  may be utilized when a STA cannot communicate directly with an AP in order to associate with the AP. At block  1402 , the process  1400  receives a request for relay connection from a STA via a relay. At block  1404 , the process  1400  transmits a message to at least one other relay based on the received request for relay connection. In an embodiment, the message comprises an instruction to transmit a setup response frame to the STA. In a further embodiment, the setup response frame may be a TDLS response frame. In a further embodiment, the STA is configured to select one of the at least one other relay based on at least one setup response frame received from at least one of the at least one other relay. In a further embodiment, the STA is configured to transmit a setup confirm frame to the selected other relay. In a further embodiment, the setup confirm frame is a TDLS confirm frame. In addition, in some embodiments the selected other relay is the relay. In other embodiments, the selected other relay is different from the relay. In a further embodiment, the STA is configured to transmit information regarding the selected other relay to the relay. After block  1404 , the process  1400  ends. 
       FIG. 15  is another functional block diagram of an exemplary device  1500  that may be employed within the wireless communication system  100 ,  300 , and  350 . The device  1500  includes means  1502  for receiving a request for relay connection from a STA via a relay. In an embodiment, means  1502  for receiving a request for relay connection from a STA via a relay may be configured to perform one or more of the functions discussed above with respect to block  1402 . The device  1500  further includes means  1504  for transmitting a message to at least one other relay based on the received request for relay connection. In an embodiment, means  1504  for transmitting a message to at least one other relay based on the received request for relay connection may be configured to perform one or more of the functions discussed above with respect to block  1404 . 
       FIG. 16  is a flowchart of a process  1600  for selecting a relay in the wireless communications system of FIGS.  1  and  3 A-D. In an embodiment, the process  1600  may be performed by a STA, such as the STA  106  or the STA  306 . In an embodiment, the process  1600  may be utilized when a STA cannot communicate directly with an AP in order to associate with the AP. At block  1602 , the process  1600  transmits a request for relay connection to an access point via a relay. In an embodiment, the access point is configured to transmit a message to at least one other relay in response to the request for relay connection. In a further embodiment, the message comprises an instruction to transmit a setup response frame. At block  1604 , the process  1600  selects one of the at least one other relay based on at least one setup response frame received from at least one of the at least one other relay. After block  1604 , the process  1600  ends. 
       FIG. 17  is another functional block diagram of an exemplary device  1700  that may be employed within the wireless communication system  100 ,  300 , and  350 . The device  1700  includes means  1702  for transmitting a request for relay connection to an access point via a relay. In an embodiment, means  1702  for transmitting a request for relay connection to an access point via a relay may be configured to perform one or more of the functions discussed above with respect to block  1602 . The device  1700  further includes means  1704  for selecting one of the at least one other relay based on at least one setup response frame received from at least one of the at least one other relay. In an embodiment, means  1704  for selecting one of the at least one other relay based on at least one setup response frame received from at least one of the at least one other relay may be configured to perform one or more of the functions discussed above with respect to block  1604 . 
       FIG. 18  is a flowchart of a process  1800  for communicating using an amplify and forward relay in the wireless communications system of FIGS.  1  and  3 A-D. In an embodiment, the process  1800  may be performed by a relay, such as the relay  320  or the association relay  330 . At block  1802 , the process  1800  receives a relay initiator frame (RIF). At block  1804 , the process  1800  receives a data frame. At block  1806 , the process  1800  transmits an amplified version of the data frame at a same or substantially same time as a time that the data frame is received if the relay initiator frame is received prior to the data frame. After block  1806 , the process  1800  ends. 
       FIG. 19  is a functional block diagram of an exemplary device  1900  that may be employed within the wireless communication system  100 ,  300 , and  350 . The device  1900  includes means  1902  for receiving a relay initiator frame (RIF). In an embodiment, means  1902  for receiving a RIF may be configured to perform one or more of the functions discussed above with respect to block  1802 . The device  1900  further includes means  1904  for receiving a data frame. In an embodiment, means  1904  for receiving a data frame may be configured to perform one or more of the functions discussed above with respect to block  1804 . The device  1900  further includes means  1906  for transmitting an amplified version of the data frame at a same or substantially same time as a time that the data frame is received if the relay initiator frame is received prior to the data frame. In an embodiment, means  1906  for transmitting an amplified version of the data frame at a same or substantially same time as a time that the data frame is received if the relay initiator frame is received prior to the data frame may be configured to perform one or more of the functions discussed above with respect to block  1806 . 
       FIG. 20  is a flowchart of a process  2000  for setting up an amplify and forward relay in the wireless communications system of FIGS.  1  and  3 A-D. In an embodiment, the process  2000  may be performed by a STA, such as the STA  106  or the STA  306 . At block  2002 , the process  2000  transmits a relay request to an AP. In an embodiment, the relay request may be transmitted by the STA to a store and forward relay, which then transmits it to the AP. In a further embodiment, the AP is configured to transmit a discovery request frame based on the relay request to at least one relay. In a further embodiment, each of the at least one relay is configured to transmit a discovery message based on the discovery request frame to the STA. At block  2004 , the process  2000  selects one of the at least one relay based on each received discovery message. At block  2006 , the process  2000  transmits a message comprising an identification of the selected one relay of the at least one relay to the AP. After block  2006 , the process  2000  ends. 
       FIG. 21  is another functional block diagram of an exemplary device  2100  that may be employed within the wireless communication system  100 ,  300 , and  350 . The device  2100  include means  2102  for transmitting a relay request to an AP. In an embodiment, means  2102  for transmitting a relay request to an AP may be configured to perform one or more of the functions discussed above with respect to block  2002 . The device  2100  further includes means  2104  for selecting one of the at least one relay based on each received discovery message. In an embodiment, means  2104  for selecting one of the at least one relay based on each received discovery message may be configured to perform one or more of the functions discussed above with respect to block  2004 . The device  2100  further includes means  2106  for transmitting a message comprising an identification of the selected one relay of the at least one relay to the AP. In an embodiment, means  2106  for transmitting a message comprising an identification of the selected one relay of the at least one relay to the AP may be configured to perform one or more of the functions discussed above with respect to block  2006 . 
     Relay Discovery 
     In an embodiment, to discover a relay, such as relay  320 , in the BSS, the STA  306  may transmit a relay discover frame request to the AP  304 . The AP  304  may then forward the relay discovery request frame to one or more relays. As an example, the relay discovery request frame may be sent as a unicast message to the AP  304  (and may encapsulate a TDLS discovery request action frame), and the AP  304  may transmit the relay discovery request frame as a broadcast message to the one or more relays. The relay discovery request frame may comprise an information element that specifies features and/or specifications that the STA  306  is looking for in a relay  320 . For example, the information element may specify whether the relay  320  should directly contact the STA  306  (e.g., as a public action frame with an action field described as a relay direct discovery response) or whether the relay  320  should contact the STA  306  via the AP  304  (e.g., as a TDLS frame with an action field described as a relay tunneled discovery response). In this way, the features and/or specification identified by the STA  306  may reduce a number of relays that respond to the relay discovery request frame broadcast by the AP  304 . 
     In an embodiment, to enable the discovery of relays, two additional action fields may be added to a category of action frames known as TDLS action frames, which originally may include eleven action fields. The twelfth action field may define a (TDLS) relay discovery request, which may indicate that the STA  306  would like to discovery relays associated with the AP  304 . The thirteenth action field may define a relay tunneled discovery response, which may indicate that the AP  304  should instruct the responding relays to contact the STA  306  via the AP  304  as described herein. 
     In addition, to enable the discovery of relays, one additional action field may be added to a category of action frames known as public action frames, which originally may include fifteen action fields. The sixteenth action field may define a relay direct discovery response, which may indicate that the responding relays should directly contact the STA  306  as described herein. 
       FIG. 22  illustrates a link identifier element  2200 , which may be included in a relay discovery request frame such as may be transmitted by AP  304  and/or STA  306  as described herein. The link identifier element  1800  may include five fields: element ID  2202 , length  2204 , BSSID  2206 , TDLS initiator STA address  2208 , and TDLS responder STA address  2210 . As an example, the element ID  2202  field may be 1 octet in length and may be used as is known in the art. Length  2204  field may be 1 octet in length and may be used as is known in the art. BSSID  2206  field may be 6 octets in length and may identify the AP  304  as described herein. The TDLS initiator STA address  2208  field may be 6 octets in length and may identify the STA  306  that initiated the relay discovery request. The TDLS responder STA address  2210  field may be 6 octets in length and may indicate a broadcast address, which may allow the STA  306  to specify that only relays need to respond to the relay discovery request frame. In addition, the broadcast address may be included in the third address field of the relay discovery request frame (e.g., address fields  364   c  and/or  374   c , as described with respect to  FIGS. 3B and 3D ). 
     In this way, the link identifier element  2200  and at least one of the new action fields as described herein may be included in a relay discovery request frame to allow an AP  304  to broadcast a relay discovery request frame to one or more relays, instructing the relays if and how they should respond to the STA  306 . 
     Secure Range Extension 
     In some embodiments, as described herein, a STA  306  may operate in a BSS even if it has a poor connection with the AP  304  or cannot communicate with the AP  304  (e.g., because the AP  304  is beyond a radio range of the STA  306 ), or even if the AP  304  cannot communicate with the STA  306 . As described herein, the STA  306  may be able to operate in the BSS through the use of a relay. In addition, the STA  306  may be able to securely associate with the AP  304  and establish a secure data connection with the AP  304  through the use of a relay. 
     In an embodiment, to allow a STA  306  to securely associate with the AP  304 , an association frame and an authentication frame may be created. For example, for an association request frame and an association response frame, the address fields may be similar to those address fields described with respect to  FIGS. 3B  and/or  3 D (e.g., the second address field ( 362   b ,  362   d ,  372   b , and/or  372   d ) may carry an address of the relay, and the third address field ( 364   a ,  364   b ,  374   a , and/or  374   b ) may carry the address of the AP  304 ). In addition, a fourth address field may be used for frames sent from the relay, such as relay  320  and/or association relay  330 , to the AP  304  and from the relay, such as relay  320  and/or association relay  330 , to the STA  306 . 
       FIG. 23  illustrates a tunneled encrypted data frame  2300  that may be used to allow a STA  306  to establish a secure data connection with the AP  304 . The tunneled encrypted data frame  2300  may comprise a MAC header  2302 , an EtherType setting  2304 , and a MAC protocol data unit (MPDU), such as encrypted MPDU  2306 . For example, the encrypted MPDU  2306  may be an encrypted data MPDU and/or an encrypted management MPDU. In this way, an encrypted data frame may be inserted into the data frame of a packet. 
       FIG. 24  illustrates a wireless communications system  2400 . In an embodiment, wireless communications system  2400  includes an AP  2404 , which may be similar to AP  304  of  FIG. 3A , a STA  2406 , which may be similar to the STA  306  of  FIG. 3A , and/or relay  2420 , which may be similar to relay  320  and/or association relay  330  of  FIGS. 3A and 3C . 
     In an embodiment, relay  2420  may include a controlled port  2440  and an uncontrolled port  2450 . If a (TDLS) relay relationship has been established between the STA  2406  and the relay  2420  using systems and processes as described herein, then data packets may be forwarded between the STA  2406  and the AP  2404  through the controlled port  2440  of the relay  2420 . However, if the relay relationship has not been established or has been terminated, then data packets may not be forwarded between the STA  2406  and the AP  2404  through the controlled port  2440  of the relay  2420 . 
     In some embodiments, even if no relay relationship has been established or it was terminated, the relay  2420  may still forward specific frames between the STA  2406  and the AP  2404  through the uncontrolled port  2450 . For example, the uncontrolled port  2450  may be used to forward association frames, authentication frames, and/or tunneled encrypted data frames as described herein. In addition, the uncontrolled port  2450  may forward extensible authentication protocol over local area networks (EAPOL) frames. 
       FIG. 25  illustrates a messaging timeline  2500  for frames that may be forwarded through the uncontrolled port  2450  of the relay  2420 . For example, the relay  2420  may transmit a beacon and/or probe response  2502  to the STA  2406  in response to a beacon and/or probe request previously transmitted (not shown). In an embodiment, the AP  2404  may then attempt to verify credentials of the STA  2406  using an extensible authentication protocol (EAP) framework. For example, the AP  2404  may transmit an EAPOL key  2504  to the uncontrolled port  2450  of the relay  2420 . The transmission may be a unicast transmission. The relay  2420  may then forward the EAPOL key  2506  to the STA  2406 . Again, the transmission may be a unicast transmission. The STA  2406  may process the received EAPOL key  2506  and generate an encrypted EAPOL key  2508  and transmit it to the uncontrolled port  2450  of the relay  2420  via a unicast transmission. The relay  2420  may then forward the encrypted EAPOL key  2510  to the AP  2404  via a unicast transmission. The AP  2404  may process the received encrypted EAPOL key  2510  and generate an encrypted EAPOL key  2512  and transmit it to the uncontrolled port  2450  of the relay  2420  via a unicast transmission. The relay  2420  may then forward the encrypted EAPOL key  2514  to the STA  2406  via a unicast transmission. The STA  2406  may process the received encrypted EAPOL key  2514  and generate an EAPOL key  2516  and transmit it to the uncontrolled port  2450  of the relay  2420  via a unicast transmission. The relay  2420  may forward the EAPOL key  2518  to the AP  2404  via a unicast transmission. In some embodiments, the association and/or authentication may then be complete if no errors occur. 
       FIG. 26  illustrates another messaging timeline  2600  for frames that may be forwarded through the uncontrolled port  2450  of the relay  2420 . The messaging timeline may include the AP  2404 , the STA  2406 , a data relay  2620 , and/or an association relay  2630 . In an embodiment, the data relay  2620  may be similar to the relay  320  of  FIGS. 3A and 3C  and the association relay  2630  may be similar to the relay  320  and/or the association relay  330  of  FIG. 3C . As an example, the STA  2406  may wish to discovery relays associated with the AP  2404  and select at least one of the relays to forward data packets between the STA  2406  and the AP  2404 . The STA  2406  may transmit a tunneled encrypted data packet (TEDP) (e.g., a tunneled encrypted data frame) relay (e.g., TDLS) discovery request frame  2602  to the uncontrolled port  2450  of the association relay  2630 . The association relay  2630  may forward the TEDP relay discovery request frame  2604  to the AP  2404 . The AP  2404  may analyze the received TEDP relay discovery request frame  2604  and transmit a TEDP relay discovery request frame  2606  to one or more relays, such as data relay  2620  and association relay  2630 . In an embodiment, the TEDP discovery request frame  2606  is a broadcast message as described herein. 
     In some embodiments, data relay  2620  and association relay  2630  may both respond to the received TEDP relay discovery request frame  2606 . The data relay  2620  may transmit the relay (e.g., TDLS) discovery response frame  2608   a  to the STA  2406  and the association relay  2630  may transmit the relay (e.g., TDLS) discovery response frame  2608   b  to the STA  2406 . Alternatively, one or both of data relay  2620  and association relay  2630  may transmit their respective relay discovery response frame  2608   a - b  to the AP  2404 , which may then forward the frame to the STA  2406 . In other embodiments, not shown, data relay  2620  and/or association relay  2630  may not respond to the TEDP relay discovery request frame, for example based on the features and/or specifications desired by the STA  2406  as described herein. 
     Based on one or more received relay discovery response frames  2608   a - b , the STA  2406  may choose a relay to relay packets between itself and the AP  2404  and transmit a TEDP TDLS setup request frame  2610  identifying the chosen relay as described herein to the AP  2404 . In an embodiment, as illustrated in  FIG. 26 , the TEDP TDLS setup request frame  2610  may be forwarded to the AP  2404  via the uncontrolled port  2450  of the association relay  2630 , which forwards a TEDP TDLS setup request frame  2612  to the AP  2404 . As illustrated in  FIG. 26 , the STA  2406  has chosen the data relay  2620  as the selected relay. However, the STA  2406  may choose any relay, including the association relay  2630  as the selected relay. 
     The AP  2404  may analyze the received TEDP TDLS setup request frame  2612  and forward a TDLS setup request frame  2614  to the selected relay (in this case, the data relay  2620 ). In an embodiment, the TEDP TDLS setup request frame  2612  encapsulates the TDLS setup request frame  2614 . If the selected relay approves the selection (e.g., it is capable of handling the STA  2406 ), the selected relay may transmit a TDLS setup response frame  2616  as described herein to the AP  2404 . The AP  2404  may then forward the TDLS setup response frame  2616  as a TEDP TDLS setup response frame  2618  to the STA  2406  via the uncontrolled port  2450  of the association relay  2630  as TEDP TDLS setup response frame  2622 . In an embodiment, the TEDP TDLS setup response frame  2618  encapsulates the TDLS setup response frame  2616 . In other embodiments, the data relay  2620  may transmit the TEDP TDLS setup response frame  2616  directly to the STA  2406 . 
     Based on the received TEDP TDLS setup response frame  2622 , the STA  2406  may generate and transmit a TEDP TDLS setup confirm frame  2624  to the uncontrolled port  2450  of the association relay  2630 , which then forward the TEDP TDLS setup confirm frame  2626  to the AP  2404 . A TDLS setup confirm frame  2628 , which may be encapsulated in the TEDP TDLS setup confirm frame  2626 , may then be transmitted to the selected relay (in this case, the data relay  2620 ). At this point, a relay relationship between the STA  2406  and the data relay  2620  (the selected relay) may be established. The data relay  2620  (the selected relay) may register itself with the AP  2404  as a relay for the STA  2406  via message  2632 . Once the relay relationship has been established, the data relay  2620  (the selected relay) may relay data packets between the STA  2406  and the AP  2404  via the controlled port  2440 . In an embodiment, when the controlled port  2440  becomes active, the uncontrolled port  2450  may be deactivated. 
       FIG. 27  is a flowchart of a process  2700  for securely communication data in a wireless communications system of  FIGS. 1 ,  3 A-D, and  2400 . In an embodiment, the process  2700  may be utilized when a STA cannot communicate directly with an AP. At block  2702 , the process  2700  relays, by a relay, association, authentication, and secure relay setup frames between a STA and an AP through an uncontrolled port of the relay. At block  2704 , the process  2700  relays, by the relay, data packets between the STA and the AP through a controlled port of the relay once the STA establishes a relay relationship with the relay. In an embodiment, if a relay relationship is established, the uncontrolled port of the relay may be deactivated. After block  2704 , the process  2700  ends. 
       FIG. 28  is a functional block diagram of an exemplary device  2800  that may be employed within the wireless communication system  100 ,  300 ,  350 , and  2400 . The device  2800  includes means  2802  for relaying association, authentication, and secure relay setup frames between a STA and an AP through an uncontrolled port of an apparatus. In an embodiment, means  2802  for relaying association, authentication, and secure relay setup frames between a STA and an AP through an uncontrolled port of an apparatus may be configured to perform one or more of the functions discussed above with respect to block  2702 . The device  2800  further includes means  2804  for relaying data packets between the STA and the AP through a controlled port of the apparatus once the STA establishes a relay relationship with the apparatus. In an embodiment, means  2804  for relaying data packets between the STA and the AP through a controlled port of the apparatus once the STA establishes a relay relationship with the apparatus may be configured to perform one or more of the functions discussed above with respect to block  2704 . 
     As used herein, the term “determining” encompasses a wide variety of actions. For example, “determining” may 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. Also, “determining” may include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory) and the like. Also, “determining” may include resolving, selecting, choosing, establishing and the like. Further, a “channel width” as used herein may encompass or may also be referred to as a bandwidth in certain aspects. 
     As used herein, a phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover: a, b, c, a-b, a-c, b-c, and a-b-c. 
     The various operations of methods described above may be performed by any suitable means capable of performing the operations, such as various hardware and/or software component(s), circuits, and/or module(s). Generally, any operations illustrated in the Figures may be performed by corresponding functional means capable of performing the operations. 
     The various illustrative logical blocks, modules and circuits described in connection with the present disclosure 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 signal (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. 
     In one or more aspects, the functions described may be implemented in hardware, software, firmware, or any combination thereof. 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. Also, 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, 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 and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Thus, in some aspects computer readable medium may comprise non-transitory computer readable medium (e.g., tangible media). In addition, in some aspects computer readable medium may comprise transitory computer readable medium (e.g., a signal). Combinations of the above should also be included within the scope of computer-readable media. 
     The methods disclosed herein comprise one or more steps or actions for achieving the described method. 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. If implemented in software, the functions may be stored as one or more instructions on a computer-readable medium. 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. Disk and disc, as used herein, include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, and Blu-ray® disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. 
     Thus, certain aspects may comprise a computer program product for performing the operations presented herein. For example, such a computer program product may comprise a computer readable medium having instructions stored (and/or encoded) thereon, the instructions being executable by one or more processors to perform the operations described herein. For certain aspects, the computer program product may include packaging material. 
     Software or instructions may also be transmitted over a transmission 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, 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 transmission medium. 
     Further, it should be appreciated that modules and/or other appropriate means for performing the methods and techniques described herein can be downloaded and/or otherwise obtained by a user terminal and/or base station as applicable. For example, such a device can be coupled to a server to facilitate the transfer of means for performing the methods described herein. Alternatively, various methods described herein can be provided via storage means (e.g., RAM, ROM, a physical storage medium such as a compact disc (CD) or floppy disk, etc.), such that a user terminal and/or base station can obtain the various methods upon coupling or providing the storage means to the device. Moreover, any other suitable technique for providing the methods and techniques described herein to a device can 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. 
     While the foregoing is directed to aspects of the present disclosure, other and further aspects of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.