TW200527846A - High speed media access control with legacy system interoperability - Google Patents

Abstract

Techniques for MAC processing for efficient use of high throughput systems that is backward compatible with various types of legacy systems are disclosed. In one aspect a first signal is transmitted according to a legacy transmission format to reserve a portion of a shared medium, and communication according to a second transmission format transpires during the reserved portion. In another aspect, a communication device may contend for access on a legacy system, and then communicate according to a new class communication protocol with one or more remote communication devices during the access period. In another aspect, a device may request access to a shared medium according to a legacy protocol, and, upon grant of access, the device may communicate with or facilitate communication between one or more remote stations according to a new protocol.

Description

200527846 IX. Description of the invention: Claim priority under 35 USC §119 This patent application claims priority from the following US provisional patent applications: Provisional patent application number 60 / 511,750 filed on October 15, 2003, entitled "Method and Apparatus for Providing Interoperability and Backward Compatibility in Wireless Communication Systems"; provisional patent application number 60 / 511,904 filed on October 15, 2003, entitled "Method, Apparatus, and System for Medium Access Control in a "High Performance Wireless LAN Environment"; provisional patent application number 60/5 13,239 filed on October 21, 2003, entitled "Peer-to-Peer Connections in ΜΙΜΟ WLAN System"; filed on December 1, 2003 Provisional Patent Application No. 60 / 526,347, entitled r Method, Apparatus, and System for Sub-Network Protocol Stack for Very High Speed Wireless LAN "; Provisional Patent Application No. 60 / 526,356, filed on December 1, 2003, titled "Method, Apparatus, and System for Multiplexing

Protocol data Units in a High Performance Wireless LAN Environment "; provisional patent application number 60 / 532,791 filed on December 23, 2003, entitled" Wireless Communications Medium Access Control (MAC) Enhancements "; filed on February 18, 2004 Provisional patent application number 60 / 545,963, marked 96852.doc 200527846 entitled "Adaptive Coordination Function (ACF)"; provisional patent application number 60 / 576,545 filed on July 2, 2004, entitled "Method and Apparatus for Robust Wireless Network "; provisional patent application number 60 / 586,841 filed on June 8, 2004, entitled" Method and Apparatus for Distribution Communication Resources Among Multiple Users "; and provisional patent application filed on August 11, 2004 No. 60 / 600,960, entitled "Method, Apparatus, and System for Wireless Communications"; their patent applications have been assigned to the same assignee as this patent application, and are expressly incorporated herein by reference. [Technical Field to which the Invention belongs] The present invention relates broadly to the field of communications, and in particular, the present invention relates to media access control. [Prior Art] Wireless communication systems are widely deployed to provide various types of communication such as voice and data. A typical wireless data system or network provides multiple users access to one or more shared resources. The system can use various multiple access technologies, such as Frequency Division Multiplexing (FDM), Time Division Multiplexing (TDM), and Code Division Multiplexing (CDM). Exemplary wireless networks Including honeycomb information system. The following are a few of these examples: (1) "TIA / EIA-95-B Mobile Station-Base Station Compatibility Standard for Dual-Mode Broadband Spread Spectrum Cellular System" Standard for Dual-Mode 96852.doc 200527846

Wideband Spread Spectrum Cellular System (IS-95 standard); (2) A standard proposed by the consortium named "3rd Generation Partnership Project" (3GPP), and is specified in a set of documents, including Symbols 3G TS 25.211, 3G TS 25.212, 3G TS 25.213, and 3G TS 25.214 (W-CDMA standard); (3) Proposed by the alliance named "3rd Generation Partnership Project 2" (3GPP2) And is specified in the "Third Generation Partnership Project" (TR_45.5 Physical Layer Standard for cdma2000 Spread Spectrum Systems; IS-2000 standard); and (4) Complies with the TIA / EIA / IS-856 standard (below A high data rate (HDR) communication system referred to herein as the IS-856 standard. Other examples of wireless systems include Wireless Local Area Networks (WLANs), such as the IEEE 802.11 standard (ie, 802.11 (a), (b), or (g)). The deployment of Multiple Input Multiple Output (MIMO) WLANs including Orthogonal Frequency Division Multiplexing (OFDM) modulation technology can improve these networks. IEEE 802.ll (e) has been adopted to improve some of the shortcomings of the previous 802.11 standards. As wireless system design progresses, higher data rates have become feasible. Higher data rates open up possibilities for advanced applications, including voice, video, fast data transfer, and various other applications. However, various applications may have different data transfer requirements. Many types of data may have delays and throughput requirements, or require a certain Quality of Service (QoS) guarantee. Without resource management, system capacity may be reduced and the system cannot operate efficiently. L 使用 Use Media Access Control (Mediuin Access Control;

MAC) protocol to configure communication resources shared between several users. The MAC protocol will typically interface higher layers to the physical layer used to transmit and receive data. To benefit from increased data rates, the MAC protocol must be designed to use shared lean sources efficiently. It is also often desirable to maintain interoperability with alternative communication standards or legacy communication standards. Therefore, this technology requires a MAC processing for efficient use of high throughput systems. In this technical field, there are seven types of MAC processing that are backward compatible with various types of legacy systems. [Summary of the Invention] The specific embodiment disclosed by this Maoming meets the demand for MAC processing which is backwards compatible with the old system and uses the system of throughput. In one case, the first signal is transmitted in accordance with the _old transmission format, thereby retaining a portion of the shared media; and during the reserved portion, transmission occurs in a second transmission format. In another secret, the -pass m can compete for legacy systems, and then communicate with one or more remote devices during a beta access period 'according to a new class communication protocol. In another aspect, the device may request access to the shared media in accordance with the old agreement, and after granting access, the device may communicate with one remote station in accordance with the new agreement ( Or facilitate communication between two or more remote sites). ::: In the item form,-the new class access point configuration-a non-competitive period and a part of the brother's contention period are configured to operate in accordance with the category agreement, 4 / L and far no competition One of the second part of the period is required as 96852.doc 200527846 to be configured to communicate according to an old agreement. This competition period can use either agreement or a combination of both. Various other points have also been made. [Embodiment] The present invention discloses that various exemplary embodiments support high-efficiency operation of a physical layer that cooperates with a wireless LAN (or a similar application using the latest market-based transmission technology) with extremely high bit rates. The exemplary WLAN supports a 20 MHz bandwidth in excess of 100 MbPs (million bits per second; bit rates per million). Various exemplary embodiments maintain the simplicity and ruggedness of the old traditional decentralized coordination operation, and examples can be found in 802 · 1 l (a-e). Each achieves the advantages of specific embodiments while maintaining backward compatibility with such legacy systems. (Note: In the following description, the 8 2 · 11 system will be used as the non-standard legacy system to explain). Those skilled in the art should understand that the improvement scheme is also compatible with alternative systems and standards. An exemplary WLAN may include a sub-network protocol stack. Subnet protocol stacks widely support high-data-rate, high-bandwidth physical layer transmission mechanisms, including (but not limited to): transmission mechanisms based on OFDM modulation; single-carrier modulation technology; suitable for use in extremely high-bandwidth efficient operations Receiving antenna and transmitting antenna system (Multiple Input Multiple Output)

Multiple Output; ΜΙΜΟ) system (ΜΙΜΟ), including multiple input single output (Multiple Input Single UTut; MIS) system); a system using multiple receiving antennas and multiple transmitting antennas in conjunction with spatial multiplexing technology for In the same case, data is transmitted to or received from user terminals during the same period; and systems using code division multiple access 96852.doc -10- 200527846 (code division multiple access; CDMA) technology, Used to allow multiple users to transmit at the same time. Alternative examples include Single Input Multiple Output (SIMO) and Single Input Single Output (SIS0) systems. One or more exemplary embodiments described herein are proposed in the context of a wireless data communication system. Although there are many advantages to using the invention in this context, different specific embodiments of the invention may also be incorporated in different environments or configurations. In general, the various systems described in this article can be constructed using software-controlled processors, integrated circuits, or discrete logic. The information, instructions, commands, information, signals, symbols, and chips mentioned throughout the specification are useful for representing voltage, current, electromagnetic waves, magnetic fields or particles, light fields or particles, or any combination thereof. In addition, the blocks shown in each block diagram may represent hardware or method steps. The method steps are interchangeable without departing from the scope of the invention. The term "demonstration" as used herein is not meant to be "served as an example, instance, or illustration". Any specific embodiment described herein as "exemplary" is not necessarily to be construed as a preferred embodiment or a preferred embodiment. FIG. 1 illustrates an exemplary embodiment of a system 100 that includes an access point (Ap) 104 connected to one or more user terminals (UT) 106A-N. According to ⑽2 · 11 terminology, AP and UT are also referred to as stations or STAs in the document. The AP and UT communicate with each other via wireless LAN (WLAN) 120. In this exemplary embodiment, WLAN 120 is a high-speed MIMOO FDM system. However, Wlan 120 may be any wireless LAN. The access point 104 communicates with any external device or process via the network 102. 96852.doc -11 · 200527846 佗. Network 1 02 may be the Internet, an intranet, or any other wired, hotline, or optical network. Connection 1 1 0 carries the physical layer signal from the network to the access point 1 104. The device or process can be connected to the network, or as a UT on the WLAN 120 (or connected to it via a connection). Examples of networks that can be connected to the network 102 or WLAN 120 include telephones, personal digital assistants (PDAs), various similar computers (laptops, personal computers, workstations, any type of terminal), video devices (for example, cameras , Camcorders, web cameras, and almost any type of data device). The processing sequence can include voice, video, data communication, etc. Various data streams have different transmission requirements, which can be adapted to each by using a variety of quality service (Quality Service; QOS) technologies. Requirements. The system can be deployed using a centralized AP 104. In an exemplary embodiment, all UTs 106 communicate with the AP. In an alternative embodiment, the system can be modified to provide Peer-to-peer communication between UT2, as known to those skilled in the art, examples will be explained below. Access rights can be managed by an AP, or ad hoc Access (ie, contention-based access). In a specific embodiment, the AP 104 provides Ethernet conditioning. In this case, in addition to the AP, a poro router can be deployed to provide connectivity to the network. The connection of the road 102 (the details are not shown in the figure). The Ethernet frame can be transmitted between the router and the UT 106 through the WLAN subnet (explained in detail below). Techniques known in one technology. In the specific embodiment, AP i 04 provides Ip adjustment. In this case, 96852.doc • 12- 200527846, AP is used as the gateway router of the connected UT (the details are not shown in the figure). Here In this case, the AP 104 can deliver IP datagrams to and from the UT 106. IP adjustment and connection capabilities are known in the art. Figure 2 illustrates an exemplary embodiment of a wireless communication device. The wireless communication device can be configured as an access point 104 or a user terminal 106. Figure 2 shows the configuration of the access point 104. The transceiver 210 receives and connects on the connection 110 according to the physical layer requirements of the network 102. Transmission. Data received from or transmitted to a device or application connected to the network 102 is passed to the MAC processor 220. This data is referred to herein as a data stream 260. The data stream may have different characteristics and will be based on that The type of application associated with the data stream requires different processing methods. For example, video or voice is characterized by a low-latency data stream (generally, the demand for video traffic is higher than the demand for voice traffic). Many data Applications are less affected by latency, but may have higher data integrity requirements (ie, voice may tolerate a packet loss, and file transfers generally do not tolerate packet loss). The MAC processor 220 receives and processes the data stream 260 in order to The data stream is transmitted on the physical layer. The MAC processor 220 receives and processes the data stream 260 to transmit the data stream on the physical layer. The AP and UT also transmit internal control and signalling. The MAC protocol data unit is connected on the connection 270 (MAC Protocol Data Unit; MAC PDU) (also referred to as a physical layer (PHY) protocol data unit (PPDU)) is passed to the wireless LAN transceiver 240 and receives MAC PDUs from the wireless LAN transceiver 240. Exemplary techniques for transitioning from data streams and commands to MAC PDUs and vice versa are described below. Substitute specific implementation 96852.doc -13- 200527846 cases can use any conversion technology. For various purposes, feedback 280 corresponding to the various MAC IDs can be passed back from the physical layer (PE) 240 to the MAC processor 220. Feedback 280 may include any physical layer information, including supported channel rates (including multicast and unicast channels), modulation formats, and various other parameters. In an exemplary embodiment, the adjustment layer (ADAP) and the data link control layer (DLC) are executed in the MAC processor 220. The physical layer (PHY) is implemented on the wireless LAN transceiver 240. Those skilled in the art should know that any of the various configurations can be used to divide the functions. The MAC processor 220 may perform some or all of the processing on the physical layer. A wireless LAN transceiver may include a processor for performing MAC processing or a sub-portion thereof. You can deploy any number of processors, special-purpose hardware, or a combination of them. The MAC processor 220 may be a general-purpose microprocessor, a digital signal processor (DSP), or a special-purpose processor. The MAC processor 220 may be connected with special-purpose hardware (not shown in detail in the figure) for supporting various tasks. Various applications can be executed on an external processor (for example, an external computer or through a network connection), or various applications can be executed on an additional processor (not shown) in the access point 104, or Various applications can be executed on the MAC processor 220 itself. The MAC processor 220 shown in the figure is connected to a memory 255. The memory 255 can be used to store data and instructions that can execute the various programs and methods described herein. Those skilled in the art should know that the memory 255 may be composed of one or more types of memory components, and may be embodied in the MAC processor 220 in whole or in part. In addition to storing instructions and data that perform the functions described in this article, 96852.doc -14- 200527846 memory 255 can also be used to store data associated with various queues. The wireless LAN transceiver 240 may be any type of transceiver. In an exemplary embodiment, the wireless LAN transceiver 240 is an OFDM transceiver capable of operating in conjunction with a MIMO or MISO interface. OFDM, MIMO and MISO are known to those skilled in the art. Common Application US Patent Application No. 10 / 650,295 filed on August 27, 2003, "FREQUENCY-INDEPENDENT SPATLAL-PROCESSING FOR WIDERAND MISO AND ΜΜΟ SYSTEMS" details various OFDM, ΜΜΟ and MISO transceivers. To the assignee of the present invention. Alternative specific embodiments may include a SIMO or SISO system. The wireless LAN transceiver 240 shown in the figure is connected to the antenna 250 A-N. Any number of antennas can be supported in various embodiments. The antenna 250 may be used for transmission and reception on the WLAN 120. The wireless LAN transceiver 240 may include a spatial processor connected to each antenna 250. The space processor can process the data to be transmitted independently by each antenna, and collectively process the signals received on all antennas. Examples of independent processing include channel-based evaluation, feedback from the UT, channel reversal, or various other techniques known in the art. This processing is performed using various known spatial processing techniques. Various types of transceivers of this type may use beam forming, beam steering, eigen-steering, or other space technologies to increase the transmission and reception throughput of a given user terminal. In a specific embodiment for transmitting OFDM symbols, the 'spatial processor' may include a plurality of subspace processors for processing each OFDM subchannel or frequency bin. 96852.doc -15- 200527846 In one exemplary system, the AP may have N antennas, and the exemplary UT may have M antennas. Therefore, there are M × N paths between the antenna of the AP and the antenna of the UT. Various space technologies using these multipaths to improve the throughput are known in the art. In the Space Time Transmit Diversity (STTD) system (also referred to herein as "diversity"), the transmitted data is formatted, encoded, and transmitted as a single data stream with all antennas. Using M transmitting antennas and N receiving antennas, it is possible to form M IN (M, N) independent channels. Spatial multiplexing utilizes these independent paths, and different data can be uploaded on each independent path. Various techniques for knowing or adjusting the channel characteristics between AP and UT have been known to transmit unique preambles by the transmission antennas. These preambles can be received and measured on each receive antenna. The channel status information can then be sent back to the transmitting device for use during transmission. The characteristic decomposition of the measured channel matrix can be performed to determine the characteristic mode of the channel. In order to avoid the frequency matrix feature decomposition, an alternative technique will use the feature #control (elgen-steering) of the preamble and data to simplify the spatial processing at the receiver. Therefore, according to the current channel status, the entire system can provide different data rates for transmission to various user terminals. Specifically, the performance of a particular link between / and the parent UT may be higher than the performance of more than one available on-demand or broadcast link. Examples are further detailed below. The wireless LAN transceiver 24o can process the rate that can be supported depending on the space used for the physical link between the AP and υτ. This information can be fed back on connection 280 for use in MAC processing. 96852.doc • 16- 200527846 Several antennas can be deployed based on υτ data and size and form factor requirements. For example, a high-definition video display may include, for example, four antennas based on high-bandwidth requirements, while a PDA may use two antennas. An exemplary access point may have four antennas. The user terminal 106 can be deployed in a manner similar to the access point 104 shown in FIG. If the data stream 260 is not connected to a LAN transceiver (although the UT may include a wired or wireless transceiver), the data stream 260 is typically received from or passed to one or more applications or processes running on the UT or connected UT device . The higher levels connected to the AP 104 or UT 106 may be of any type. The layers described herein are for illustration only.

Legacy 802.1 1 MAC As described above, the specific embodiments described in this article can be deployed to make it identical to legacy systems. The IEEE 802 · 11 (e) feature set, which is retroactively compatible with earlier 802.11 standards, includes features outlined in this section, and also includes features included in earlier standards. For a detailed description of these functions, please refer to the corresponding IEEE 802.1 1 standard. The basic 802.1 1 MAC is composed of Carrier Sense Multiple Access / Collision Avoidance (CSMA / CA) type decentralized coordination function (DCF) and point coordination function (PCP). DCF allows media to be accessed without central control. The PCF is deployed at the AP to provide central control. DCF and PCF use gaps between successive transmissions to avoid collisions. Transmission is called frame, and the gap between frames is called Interframe Spacing (IFS). The frame may be a 96852.doc -17- 200527846 user data frame, a control frame, or a management frame. The duration of the space between frames varies depending on the type of gap inserted. Figure 3 shows the 802.1 1 inter-frame spacing parameters: Short Interframe Spacing (SIFS), Point Interframe Spacing (PIFS), and DCF Interframe Spacing (DIFS). . Please note that SIFS < PIFS < DIFS. Therefore, the priority of transmissions after a short duration is higher than the priority of transmissions that must wait for a longer duration before attempting to access a channel. According to the carrier sense function (CSMA) of CSMA / CA, a station (STA) can obtain an access channel after the sensing channel is idle for at least one DIFS duration. (In this article, the term STA can mean any station that is accessing the WLAN, and can include access points and user terminals). To avoid collisions, each STA, after accessing the channel, needs to wait for a randomly selected backoff in addition to waiting for DIFS. A STA with a longer return will notice when a higher priority STA is transmitting on the channel and avoid collisions with that STA in this way. (Each waiting STA can return its own to reduce the amount of time it has waited before the alternate transmission on the inductive channel, in this way maintaining its relative priority). Therefore, after the agreed collision avoidance (CA) function, the STA returns a random period between [0, CW], where the initially selected CW is CWmin, and each collision is increased by a factor of 2 until the maximum value CWmax is reached Figure 4 shows an exemplary physical layer (PHY) transport segment 400, using 96852.doc -18-200527846 to explain the use of DIFS plus return for access in accordance with DCF. An existing transmission 410 uses channels. In this example, when transmission 410 terminates, no higher-priority accesses occur, so a new transmission 420 will begin after DIFS and the associated return period. In the following discussion, it is assumed that the STA transmitting 420 has won the transmission opportunity (in this case, through competition). SIFS is used during the frame sequence in which only a specific STA is expected to respond to the current transmission. For example, when transmitting an acknowledgement (ACK) in response to a received data frame, the ACK is transmitted immediately after the received data is added to the SIFS. Other transmission sequences can also use SIFS between frames. After SIFS, a "Request To Send; RTS" can be followed by a "Clear To Send; CTS", and then the data can be transmitted during a SIFS after the CTS, after the SIFS An ACK may follow this information. It is known that the sequence of such frames is interspersed with SIFS. The duration of SIFS can be used for: (a) detecting the energy on the channel, and determining whether the energy is exhausted (ie, channel clear); (b) resolving the previous message and determining whether an ACK frame will indicate The time at which the transmission was received correctly; and (c) the time at which the STA transceiver switched from reception to transmission (and vice versa). FIG. 5 illustrates an exemplary physical layer (PHY) transmission segment 500 for illustrating the use of SIFS before an ACK in a priority order over a DIFS access. An existing transmission 510 uses channels. In this example, when transmission 510 terminates, after DIFS, ACK 520 will follow after transmission 510 ends. Please note that ACK 520 will start before a DIFS timeout, so any other STA attempting to win the transmission of 96852.doc -19- 200527846 will not succeed. In this example, after ACK 520 is completed, no higher-priority accesses occur, so the new transmission 530 will begin after DIFS and the associated return period (if any). RTS / CTS frame sequence (in addition to providing flow control functions) can be used to improve data frame transmission protection. RTS and CTS contain duration information about subsequent data frames, ACKs and any intervening SIFS. STAs that are listening to RTS or CTS will set an occupation duration on their network allocation vector * (NAV) and will treat the media as busy during this duration. Generally, RTS / CTS is used to protect frames longer than a specified length, and shorter frames are transmitted without protection. PCF can be used to allow the AP to provide channel central control. An AP can gain control of the media after sensing that the media has been idle for the duration of a PIFS. PIFS is shorter than DIFS and therefore has higher priority than DIFS. Once the AP has obtained channel access, it can provide contention-free access to other STAs. Therefore, compared with DCF, MAC performance will be improved. Please note that SIFS takes precedence over PIFS, so the PCF must wait for any SIFS sequence to complete before gaining control of the channel. Once the AP has used PIFS to obtain media access, it can establish a Contention-Free Period (CFP), during which the AP can provide polling access to the associated STAs. Contention-free poll (CF-Poll) (or directly referred to as "polling") is transmitted by the AP, and then transmitted from the polled STA to the AP. Once again, the STA must wait for a SIFS duration of 96852.doc -20- 200527846 after the CF-Poll. However, the STA being polled does not need to wait for the return of DIFS or any of the enhancement schemes (including the polling enhancement scheme). 8 〇2.u (e), an example will be described in detail below with reference to FIG. 9. The beacon signal (Beacon) transmitted by the AP will establish the CFp duration. This is similar to using RTS or CTS to prevent contention access. However, 'still will cause the terminal to be unable to listen to the beacon signal (Beacon) to cause a hidden terminal, but such hidden terminals may interfere with the transmission scheduled by Ap. Further protection can be implemented by using one CTS_to-self for each terminal that starts a transmission during the CFP. Both ACK and CF-Poll are permitted to be included in a frame and can be included in a frame together with a data frame, thereby improving MAC efficiency. Note that the SIFS < PIFS < DIFS relationship provides a deterministic priority mechanism for channel access. Competitive access between STAs in DCF is based on the probability of a bounce mechanism. The early 802.1 1 standard also provided for segmenting large packets into smaller fragments. The advantage of this segmentation process is that errors in one segment require less retransmissions than errors in larger packets. One disadvantage of the split processing in their standards is that for approved transmissions, an ACK needs to be transmitted for each segment, and an additional SIFS corresponding to their ACK transmission and segment transmission is needed. This situation is illustrated in FIG. 6. FIG. 6 illustrates an exemplary physical layer (PHY) transmission segment 600 for illustrating the transmission of N segments and corresponding approvals. The existing transmission 610 is transmitted. At the end of transmission 61, a first STA waits for DIFS 620 and returns 630 in order to win channel access. The first STA transmits N segments 640A-640N to a second STA, and then it is fixed to 96852.doc • 21- 200527846 Delay SIFS 650A-650N must occur. The second STA transmits N ACK frames 660A-660N. Between each segment, the first STA must wait for SIFS, so there are N-1 SIFS 670A-670N-1. Therefore, related to transmitting one packet, one ACK, and one SIFS, a divided packet requires the same packet transmission time, and also requires N ACKs and 2N-1 SIFS. The 802.11 (e) standard adds enhancements to improve the MAC of the previous 802.11 (a), (b), and (g) standards. 802.11 (g) and (a) are both OFDM systems. They are very similar, but operate in different frequency bands. The functions of lower-rate MAC protocols (for example, 802.11 (b)) are transferred to higher-bit-rate systems, which can cause inefficiencies, as described in detail below. In 802.11 (e), DCF has been enhanced and is called Enhanced Distributed Channel Access (EDCA). EDCA's main Quality of Service (QoS) enhancement scheme refers to an inter-arbitration frame spacing (Arbitration Interframe Spacing; AIFS). AIFS [i] is associated with a traffic class (TC) identified by index i. The AIFS [i] value used by the AP may be different from the AIFS [i] value that has been allowed to be used by other STAs. Only the AP can use an AIFS [i] value equal to PIFS. Otherwise, AIFS [i] is greater than or equal to DIFS. By default, the AIFS for "voice" and "video" traffic levels is selected to be equal to DIFS. A larger AIFS means choosing a lower priority for traffic levels "best effort" and "background". The contention window size is also a function of TC. The highest priority level is permitted to set CW = 1, that is, no return. For other tc, different contention window sizes provide a probability-related priority order, but cannot be used up to 96852.doc -22- 200527846 as a latency guarantee. 802.11 (e) uses Transmission Opportunity (TXOP). In order to improve MAC efficiency, when a STA obtains media through EDCA or through a polling access in HCCA, the STA may be permitted to transmit more than a single frame. Their one or more frames are called TX0P. The maximum length of the previous TX0P depends on the traffic level and is set by the AP. Furthermore, for polling TXOP, the AP indicates the duration of the TXOP allowed. During TX0P, the STA can transmit a series of frames interspersed with SIFS and from the destination ACK. In addition to not needing to wait for DIFS plus return per frame, STAs that have won a TXOP must reserve channels for subsequent transmission. During this TXOP, the ACK from the destination may be per-frame (as in earlier 802.11 MACs), or an immediate or delayed block ACK may be used, as described below. Furthermore, some traffic processes (for example, broadcast or multicast) do not allow any ACK principles. FIG. 7 illustrates an exemplary physical layer (PHY) transmission segment 700 for illustrating a TXOP with per-frame approval. The existing transmission 710 is transmitted. After transmitting 710 and waiting for DIFS 720 and returning 730 (if any), a STA wins TXOP 790. TXOP 790 includes N frames 740A-740N, each frame is followed by N corresponding SIFS 750A-750N. The receiving STA responds with N corresponding ACKs 760A-760N. ACK 760 is followed by N-1 SIFS 770A-770N-1. Note that each frame 740 includes a leading item 770 and a header and packet 780. The exemplary embodiment detailed below allows a significant reduction in the amount of transmission time reserved for the leading term. Figure 8 shows a TXOP 810 with block recognition. Can win through competition or polling 96852.doc -23- 200527846. Ding Yi 0 ~ 810 includes fixed frame 820-8-8201 ^, each frame is followed by N corresponding SIFS 830A-830N. After transmitting frame 820 and SIFS 830, a block ACK request 840 is transmitted. The receiving STA responds to the block ACK request at a future time. The block ACK can be immediately after the completion of a block frame transmission, or it can be delayed to allow the receiver to process it with software. The exemplary embodiment detailed below allows a substantial reduction in the amount of transmission time between frames (SIFS in this example). In some embodiments, no delay is required between consecutive transmissions (i.e., frames). Note that in 802.11 (a) and standards, for some transmission formats, a signal extension is defined to add additional delay at the end of each frame. Although not technically included in the SIFS definition, the specific embodiments detailed below also allow the signal extension to be removed. The block ACK function provides improved efficiency. In one example, a STA can transmit up to 64 MAC Service Data Units (SDUs) corresponding to 1024 frames (each SDU may be divided into 16 segments), while permitting the destination The STA provides a single response at the end of each frame block, which is used to indicate the ACK status of each frame of their 1024 frames. Generally speaking, at high rates, MAC SDUs are not split, and based on low latency, less than 64 MAC SDUs may be transmitted before a block ACK is required from the destination. In this case, the total time for transmitting M frames is shortened from M frames + M SIFS + M ACK + M-1 SIFS to M frames + M SIFS + block ACK. The specific implementation examples detailed below further improve block A C K efficiency. 96852.doc -24- 200527846 802.1 1 (e) The Direct Link Protocol (DLP) used allows a STA to directly forward a frame to another in a Basic Service Set (BSS) Destination STA (controlled by the same AP). The AP can set up a polling TX0P that can be used to directly transfer message frames between STAs. Before using this function, during polling access, the frame destination from the polled STA must be the AP, and then the AP forwards the frame to the destination STA. Improved media efficiency by excluding two skip frame forwards. The specific embodiments detailed below substantially increase DLP transfer efficiency. 802 · 11 (e) also uses an enhanced PCF, called Hybrid Coordination Function (HCF). In HCF Controlled Channel Access (HCCA), the AP is allowed to access the channel at any time to establish a Controlled Access Phase (CAP). CAP is similar to CFP and is used in Opportunities for transmission are provided at any time during the competition phase, rather than just after the beacon signal. The AP accesses the media by waiting for a non-returned PIFS. FIG. 9 illustrates an exemplary physical layer (PHY) transmission segment 900 for illustrating a polling TXOP using HCCA. In this example, APs compete for polling. The existing transmission 910 is transmitted. After transmitting 910, the AP waits for the PIFS and then transmits a poll 920 that transmits a certain address to a STA. Please note that other STAs competing for the channel must wait for at least DIFS. DIFS does not occur due to the polling of this transmission, as shown in the figure. The polled STA transmits polling TX0P 940 after polling 920 and SIFS 930. The AP continues to poll and waits for a PIFS between each polling TX0P 940 and polling 920. In the case of the 96852.doc -25- 200527846 generation, the AP can build a CAP by waiting for the PIFS from a transmission 910. The AP may transmit one or more polls during this CAP. MAC improvements As mentioned above, the inefficiency features of the previous MAC will be transferred to later versions. For example, very long preambles designed for 11 Mbps versus 64 Mbps can cause inefficiencies. Since the MAC Protocol Data Unit (MPDU) will continue to decrease as the rate increases, maintaining constant inter-frame space and / or leading terms means that channel utilization will be relatively reduced. For example, compared to 802.1 1 (g) with a leading entry of 72 microseconds, a high data rate MIM0 MPDU transmission may be only a few microseconds. Eliminating or reducing delays (for example, SIFS, signal extension, and / or preamble) will increase throughput and channel utilization. FIG. 10 illustrates an exemplary embodiment of a TXOP 1010 including multiple continuous transmissions without any gaps. TXOP 1010 includes N frames 1020A-1020N, which are transmitted continuously without any gaps (in contrast, TXFS 810 shown in Figure 8 requires SIFS). The number of frames in TXOP is limited only by the buffer and decoding capabilities of the receiver. When a STA is transmitting a continuous frame with a block ACK in a TXOP 1010, there is no need for any other STA to obtain media access between the continuous frames, so there is no need to intersperse the SIFS. An optional block ACK request 1030 is appended to these N frames. Certain traffic classes may not require approval. It can respond to a block ACK request immediately after TXOP, or transmit the block ACK request at a later time. The frame 1020 does not require signal extension. TXOP 1010 may be deployed in any specific embodiment detailed herein that requires TXOP. 96852.doc -26- 200527846 As shown in Figure ο, when the same STA transmits all the continuous frames in a τχ〇ρ, it can exclude the transmission of SIFS between consecutive frames in the TXOP. In 802.1 (e), this type of backlash was reserved to limit the complex requirements of the receiver. In the 802.11 (e) standard, the 10 microsecond SIFS period and the 6 microsecond OFDM signal extension provide the receiver with a total time of 16 microseconds for processing the received frame, including demodulation and decoding. However, at high ρΗγ rates, this 16 seconds can lead to significant inefficiencies. In some embodiments, even with 16 μs, the processing may be inefficiently completed. Instead, in this exemplary embodiment, the sifs and OFDM signal extension between consecutive transmissions from a certain STA to Aρ * another STA (using a direct link protocol (DLP)) are excluded. Therefore, receivers that require an additional period of time (for MIMO receiver processing and channel decoding (such as Juice 0 / Convolution / LDPC decoding)) can perform their functions while completing the transmission, while utilizing the media for additional transmissions. An acknowledgement may be transmitted at a later time, as described below (for example, using a block ACK). Due to the different propagation delays between STAs, a guard period can be used to separate transmissions between different pairs of STAs, thereby avoiding a receiver at the receiver between media from different STAs Collisions between consecutive transmissions (not shown in Figure 10, but described in detail below). In an exemplary embodiment, a guard period (4 microseconds) of one OFDM symbol is sufficient for all operating environments of 802.11. Transmission from the same STA to different destination STAs does not need to be performed using the guard period (as shown in Figure 10). In the detailed description below, their guard periods are called Guardband Interframe Spacing (96852.doc -27- 200527846 GIFS). 〇If SIFS and / or 〇! 7! , Can provide the required receiver processing time (for example, for MIMO processing and decoding) by using a windowed ARQ mechanism (for example, g0 back N (selective repeat) or selective repeat), which belongs to Techniques familiar to those skilled in the art. In this example, the old 802 · η * stop and wait (st. And walt) MAC layer ACKs have been enhanced in 802el 1 (e) to look like windows with up to 1024 frames and block ACKs. mechanism. The preferred method is to use a standard window-based ARQ mechanism instead of the 80211 (private block ACK mechanism designed by Magic. The receiver's processing complexity and buffer processing can be used to determine the maximum permitted window. The transmitter may be allowed to transmit data at a peak PHY rate between the pair of transmitter-receivers that is sufficient to fill the receiver window. For example, because the receiver processing may not keep up with the ρΗγ rate, the receiver The soft demodulator outputs must be stored until their outputs can be decoded. Therefore, at the peak PE rate, the buffer processing requirements of the physical layer processing can be used to determine the maximum permitted window. In a non-expendable embodiment In the receiver, the receiver can announce the maximum allowed ρΗγ block size that it can handle at a given PΗΥ rate without causing the entity layer buffer to overflow. Alternatively, the receiver can declare the maximum which it can handle at the maximum PΗΥ rate. Allows ρΗγ block size without causing • Owned shell layer buffer to overflow. At lower P 较低 rates, longer blocks can be processed Size 'without causing the buffer to overflow. The transmitter can use the maximum permissible _ block m # «processed at the maximum P rate reported 96852.doc -28- 200527846 PHY block size to calculate a given Pγ The maximum allowed ρΗγ block size at the rate. If the declared maximum PΗΥ block size is a static parameter, the amount of time before the physical layer buffer can be processed and the receiver is ready to receive the next PΗγ burst is another Receiver parameters, and the transmitter and scheduler may know the parameters. Or, the declared maximum PΗΥ block size may change dynamically according to the occupied physical layer buffer. The receiver processing delay can be used to determine the ARQ round trip. Delay, and then the ARQ round-trip delay can be used to determine the delay perceived by the application. Therefore, in order to achieve low-latency services, the permitted ρΗγ block size can be limited. Figure 11 shows a demonstration of TXOP 111 A specific embodiment is used to explain the reduction of the necessary uranium pilot uranium pilot pilot (pilot preamble) transmission amount. D χορ 1Π0 includes the leading term 112, followed by N One continuous transmission 113〇A_ 1130N. An optional block ack requirement 1140 can be attached. In this example, one transmission 1130 includes a header and a packet. Compare τχορ mo with TX0P 790, τχ〇ρ shown in Figure 79. In addition to the header and packet, the parent frame 740 also includes a preamble item. By transmitting a single preamble item, for the same amount of data transmitted, the necessary preamble item transmission is a preamble item, not N The leading item. Therefore, the leading item 112 can be excluded from continuous transmission. The receiver can use the starting leading item 120 to obtain the signal, and it is suitable for the subtle frequency acquisition of 0FDM. For MIT transmission, it can be relative to the current rffdm preamble Item to expand the starting predecessor item 1120, enabling the receiver to exclude space channels. However, 96852.doc -29- 200527846 is' the subsequent frames within the same TXOP may not require additional leading items. The leading audio (pil o t tne) within the 〇fdm symbol is usually sufficient for signal tracking. In an alternative embodiment, during TXOP 丨 丨 丨, additional (like preamble) symbols may be broadcast periodically. However, the overall preamble overhead can be significantly reduced. The leading item may be transmitted only as needed 'and may be transmitted in different ways depending on the amount of time that has elapsed since the previous leading item was previously transmitted. Please note that TXOP 111〇 can also incorporate the functionality of legacy systems. For example, block ACK is optional. Can support more frequent ACKs. Even so, a shorter gap (e.g., GIFS) can replace a longer SIFS (plus signal extension 'if used). Their continuous transmission 丨 丨 3 〇 Can also include larger

A fragment of the packet, as described above. Please note that the headers of consecutive transmissions 1130 to the same recipient STA can be compressed. Examples of compression headers are detailed below. FIG. 12 illustrates an exemplary embodiment of a method 1200 for incorporating the aforementioned aspects, including merging leading items, removing gaps such as §11 ^, and inserting GIFs where appropriate. The process starts at step 121o, where a STA wins a τχ〇ρ using the techniques detailed herein. At step 1220 'a preamble is transmitted as needed. Again, the leading term may be longer or shorter; the old quoted term, and will vary based on various parameters (for example, the time elapsed since the J 'term of the last transmission), prompting the receiver sta to exclude the MIMOM space Channel. At step 123 (), it appears to transmit—or multiple packets (or, broadly, any kind of continuous transmission) to the destination. Note that no additional preambles need to be transmitted. In the _ item alternative embodiment, 96852.doc -30 · 200527846 can be selected to transmit one or more additional leading items, or intersperse like leading item symbols if necessary. In step 1240, the STA may selectively transmit to an additional receiving STA. In this case, a gif is inserted as needed, and one or more consecutive transmissions can be transmitted to the additional receiver STA. The program then stops. In various embodiments, the STA may continue to transmit to more than two STAs, and insert GIFS and / or leading items according to the requirements of the desired performance level. Therefore, as described above, the performance can be further improved by merging transmissions from one STA to multiple destination STAs into continuous transmissions, thus eliminating many or all guard periods and reducing leading-edge additions. A single preamble (or preamble transmission) can be used for multiple consecutive transmissions from the same STA to different destination STAs. In the example, several polls can be combined into one control channel. The example will be described in detail below. In the example, Ap can transmit a signal including a polling message for assignment to multiple destination STAs. In contrast, in 802.U, a CF_ from the AP will be placed in front of each TX0P. Additional performance can be obtained by combining polling. In-an exemplary implementation, followed by -SIFS. When several such CF-PoU messages are merged into a control channel message for assigning several TXOPs (referred to as the SC brain message in the exemplary and embodiment, as described below), it is improved. Do this. In this general embodiment, any time period can be configured: polling for merger and its respective secretary. Refer to Figure ㈣ below. Paraphrasing-specific examples of non-standard examples, and examples herein. ^ Use a stepped rate structure to encode a control channel (ie, SCHED) 96852.doc -31- 200527846 message to improve efficiency. A polling message to any STA can be encoded according to the channel quality between the AP and the STA. The transmission order of the polling messages does not need to be the order of the assigned TXOPs, but can be sorted according to the coding robustness. FIG. 13 illustrates an exemplary physical layer (PHY) transmission segment 1300 for explaining merge polling and the corresponding TXOP. Merged polls 13 10 are transmitted. Polling can be transmitted using a control channel structure (examples will be detailed in this article), or polling can be transmitted using hybrid alternative technologies, which are easy for those skilled in the art to understand. In this example, to eliminate the need for inter-frame spacing between polling and any forward link TXOP, the forward link TXOP 1320 is transmitted directly after the combined poll 1310. After the forward link TXOP 1320, each reverse link TXOP 13 30A-13 30N is transmitted, and GIFS 1340 is inserted as needed. Note that when performing continuous transmission from a STA, it is not necessary to include GIFS (similar to forward link transmission from AP to each STA does not require GIFS). In this example, the reverse link TXOP includes a STA-to-STA (ie, peer-to-peer) TXOP (eg, using DLP). Please note that the transmission sequence shown in the figure is for illustrative purposes only. The forward link TXOP and reverse link TXOP (including peer-to-peer transmission) can be exchanged or interspersed. Some configurations do not result in the exclusion of as many gaps as others. As taught in this article, those skilled in the art can easily adjust many hybrid alternative embodiments. FIG. 14 illustrates an exemplary embodiment 1400 of a method for merge polling. The procedure starts at step 1410, where the channel resources are configured as one or more TXOPs. Any scheduling function can be deployed for TXOP configuration. 96852.doc -32- 200527846 Decision. At step 1420, the polls used to assign TXOPs as configured are merged. At step 1420, the combined poll is transmitted to one or more STAs on one or more control channels (ie, CTRLJ segments of the SCHED message, as described in an exemplary embodiment detailed below). . In an alternative embodiment, any messaging technology can be deployed to transmit the combined polls. In step 1440, the STA transmits TXOP according to the polling configuration in the merged poll. The program then stops. This method can be deployed in conjunction with a combined polling interval of any length (which can include all or part of the system beacon interval). Merge polling can be used intermittently with contention access or legacy polling, as described above. In an exemplary embodiment, method 1400 may be repeated periodically or according to other parameters (e.g., system load and data transmission requirements). Exemplary specific embodiments of the MAC protocol for explaining various aspects will be described in detail with reference to FIGS. 15 and 16. Common application US patent application No. χχ / χχχ, χχχ, χχ / χχχ, χχχ and XX / XXX, XXX (Nominee Case Nos. 030428, 030433, 030436) filed together with this patent application, entitled "WIRELESS "LAN PROTOCOL STACK" details the mac agreement, which has been transferred to the assignee of the present invention. FIG. 15 illustrates an exemplary TDD MAC frame interval 1500. The term "TDD MAC frame interval" is used herein to denote the period used to define the various transmission segments detailed below. The TDD MAC frame interval 1500 differs from the generic term "frame" used to describe transmission in 802-1 1 systems. With regard to 802.1 1, the TDD MAC frame interval 1500 may be similar to a beacon interval or a fraction of a beacon interval. The parameters detailed with reference to FIGS. 15 to 16 96852.doc -33- 200527846 are only examples. Some or all of the components described are used to match various parameter values. Those skilled in the art can easily adjust this example to cooperate with the hybrid alternative to the specific embodiment. The MAC function 1500 is configured between the following transmission channel segments: broadcast, control, forward and reverse traffic (referred to as download link phase and upload link phase, respectively), and random access. In this exemplary embodiment, time division duplex processing (TDD)-TDD MAC frame interval is 1500 within a time interval of 2 ms (milliseconds), thereby dividing into five transmission channel segments 1510-1550 ,as the picture shows. Alternative orders and different frame sizes can be deployed in alternative embodiments. The duration of the TDD MAC frame interval 1500 configuration can be quantized into a small common time interval. The exemplary five transmission channels within the TDD MAC frame interval 1500 include: (a) Broadcast Channel (BCH) 15 10, used to carry the Broadcast Control Channel (BCCH); (b) Control Channel (Control Channel; CCH) 1520, used to upload Frame Control Channel (FCCH) and Random Access Feedback Channel (RFCH); (c) Traffic channel Channel; TCH), used to carry user data and control information, and is subdivided into (i) Forward Traffic Channel (F-TCH) 1530 on the forward link, and (ii) reverse link Reverse Traffic Channel (R-TCH) 1540 on the road; and (d) Random Access Channel (RCH) 1550, used to carry Access Request Channel (ARCH) ( For UT access requirements). A pilot beacon signal will also be transmitted in the fragment 96852.doc -34- 200527846 1 5 10. The frame 1500 in the download link phase includes fragment 151 (M 530. The segment in the upload link phase includes fragments 1540-1550. The fragment 1560 indicates the start of a subsequent TDD MAC frame interval 1500. The following further explains alternative implementations that include peer-to-peer transmission example.

The AP transmits a broadcast channel (BCH) and a beacon signal (Beacon) 1510. A part of BCH 510 includes a common physical layer overhead, such as a preamble signal, including timing and frequency acquisition preambles. In an exemplary embodiment, the beacon signal consists of the following two short OFDM symbols used by the UT for frequency and timing acquisition; subsequent connections are used by υτ to evaluate the commonality of channels The 8 short OFDM symbols of the MIMO preamble. The second part of BCH 15 10 is the information part. The BCH data section defines the TDD MAC frame interval configuration for transmission channel segments: CCH 1520,

F-TCH 1530, R-TCH 1540, and RCH 1550, and also define CCH combinations for sub-channels. In this example, BCH 15 10 defines the coverage of wireless LAN 1 20 and will be transmitted in most of the rugged data transmission modes available. The length of the entire BCH is fixed. In an exemplary embodiment, the BCH defines the coverage of MIMO-WLAN, and will use Binary Phase Shift Keying (BPSK) in space time transmission diversity (Space Time Transmission Diversity). Transmit Diversity; STTD) mode. In this example, the length of the BCH is fixed to 10 short OFDM symbols. Various other signaling techniques may be deployed in alternative embodiments. 96852.doc -35- 200527846 The control channel (CCH) 1520 is transmitted by the AP, and defines the combination of TDD MAC frame interval remainders, and explains the use of combined polling. The Cch 1520 is transmitted in multiple sub-channels using a high-rugged transmission mode, each sub-channel having a different data rate. The first subchannel is the strongest and is expected to be decoded by all UTs. In an exemplary embodiment, a BPSK with a ratio of ι / 4 yards is used for the first CCH subchannel. Several other sub-channels can also be used, and the robustness of their sub-channels will decrease (and the efficiency will increase). In an exemplary embodiment, at most three additional subchannels will be used. Each υτ will try to decode all subchannels in sequence until the decoding fails. The (: :(: :) 9 [transmission channel segment is variable length in each frame, the length depends on the number of CCH messages in each subchannel. It will be uploaded on the strongest (first) subchannel of CCH. Acknowledgment of random access bursts to the link. CCH contains physical layer burst assignments for forward and reverse links (similar to TXOP's merge polling). Assignments may be used in the forward direction Data is transmitted on the link or reverse link. Generally speaking, a physical layer burst assignment includes: (a) — MAC ID, (b) — a value indicating the start time of the configuration in the frame (in the F-TCH or (R-TCH); (c) the configured length; (d) the length of the added item of the dedicated physical layer; (e) the transmission mode; and the coding and modulation mechanism used for the physical layer burst. Other demonstrations about CCH Type assignments include: an assignment for the reverse link for transmission from __υτ-dedicated preamble; or an assignment for the reverse link for transmission from υτ-buffer and link status information. Cch also You can just keep the unused part of the frame.υτ ^ Use of the frame 96852.doc -36- 200527846 and other unused parts for noise floor (and interference) assessment and measurement of beacon signals of nearby systems. Random Access Channel (RCH) 1550 is a UT that can be used for transmission—the inverse of random access bursts. To the link channel. 11 (: 11 variable length of each frame will be specified in the BCH. The forward traffic channel (F-TCH) 1530 includes one or more physical layer bursts transmitted from the AP 104. It will follow The instructions in the CCH assignment direct each burst to a special MAC ID. Each burst includes a dedicated physical layer addition (for example, a preamble signal (if any)), and a The MAc transmitted by the coding and modulation mechanism indicated in the assignment. TCH is of variable length. In an exemplary embodiment, the dedicated entity layer addition may include a dedicated MIM0 preamble. The exemplary is described in detail with reference to FIG. 16 MAC PDU. Reverse Traffic Channel (R-TCH) 1540 includes physical layer burst transmissions transmitted from one or more! ^ 106. According to the instructions in the CCH assignment, each burst is transmitted by a special UT. .Each burst includes a preamble signal preamble The term (pilot preamble), if any, and an "Ac ρ〇υ" transmitted in accordance with the transmission mode and the coding and modulation mechanism indicated in the CCH system. R-TCH is of variable length. In this exemplary embodiment, F-TCH 530, R-TCH 540, or both may use spatial multiplexing or coded multi-directional proximity technology, thereby allowing the same day to transmit and associate with different UT ^ MAC pDUs. A field containing the MAC ID associated with mac pDUm (ie, the sender on the upload link, or the intended recipient on the download link) can be included in the MAC PDU header. This field can be used by 96852.doc -37- 200527846 to resolve address ambiguity caused by spatial multiplexing or CDMA. In alternative embodiments, if the multiplexing system is strictly based on time-sharing technology, since the CCH message used to configure a TDD MAC frame interval to a specific MAC ID includes addressing information, the MAC PDU label No MAC ID is needed in the header. Space multiplexing, code division multiplexing, time division multiplexing, and any other technique known in the art can be deployed. FIG. 16 illustrates the form of an exemplary MAC PDU 1660 from a packet 1610 (in this example, it may be an IP data element or an Ethernet segment). Exemplary field sizes and types are described in this illustration. Those skilled in the art will appreciate that various other sizes, types, and configurations are considered to be within the scope of the present invention. As shown in the figure, the data packet 161 is divided into fragments at the adjustment layer. Each regulatory sublayer PDU 1630 carries one of its fragments 1620. In this example, the data packet 1610 is divided into N segments 1620A-N. A moderator layer PDU 1630 includes a packet payload 1634 containing a corresponding segment 1620. A type field 1632 (a byte in this example) is appended to the adjustment sublayer PDU 1630. A logical link (LL) header 1644 (4 bytes in this example) is attached to the packet bearer 1644 containing the conditioning sublayer PDU 1630. Exemplary information of the LL header 1 642 includes a stream identification item, control information, and a serial number. The header 1642 and the packet bearer 1644 are used to calculate and append a CRC 1646 to form a logical link sublayer pdu (LL PDU) 1640. The logical link control (LLC) PDU and the radio chain 96852.doc -38- 200527846 way control (RLC) PDU can be formed in a similar manner. Both the LL PDU 1640 and LLC PDU spearhead RLC PDUs are placed in queues (eg, high QoS queues, best effort queues, or control message queues) to be served by the MUX function. A MUX header 1652 is attached to each LL PDU 1640. An exemplary MUX header 1652 may include a length and a type (in this example, the header 1652 is 2 bytes). Available for each control? 01; (ie, 1 ^ €? 01; and RLC PDU) to form a similar header. The LL PDU 1640 (or, LLC or RLC PDU) constitutes a packet bearer 1654. The header 1652 and the packet bearer 1654 constitute a MUX sublayer PDU (MPDU) 1650 (the MUX sublayer PDU is also referred to herein as a MUX PDU). In this example, the MAC protocol allocates communication resources on the shared media in a series of TDD MAC frame intervals. In alternative embodiments, examples will be described in detail below. Their types of TDD MAC frame interval 1500 can be interspersed with various other MAC functions (including contention or polling) and include using other types of access protocols to interface Legacy system. As mentioned above, a scheduler can determine the physical layer burst size configured for one or more MAC IDs in each TDD MAC frame interval (similar to TXOP for merge polling). Please note that not all MAC IDs containing the data to be transmitted will be allocated in the space of any particular TDD MAC frame interval. Any access control or scheduling mechanism can be deployed, which is within the scope of the present invention. When configuring a MAC ID, the MUX function corresponding to the MAC ID will constitute a MAC PDU 1660, which contains one or more MUX PDUs 1650 to be included in the TDD MAC frame interval. One or more MAC PDUs 1660 of one or more configured MAC IDs are included in a TDD MAC frame interval 96852.doc -39- 200527846 (ie, TDD MAC frame interval 1500 detailed with reference to FIG. 15) . In an exemplary embodiment, an aspect allows transmission of a local MPDU 1650, thereby allowing efficient packaging in a MAC PDU 1660. In this example, the untransmitted byte count of any local MPDU 1650 left over from the previous transmission (identified by local mpdu 1664) may be included. Their bytes 1666 are transmitted before any new PDUs 1664 (ie, LL PDUs or control PDUs) in the current frame. The header 1662 (2 bytes in this example) includes a MUX indicator to point to the beginning of the first new MPDU (MPDU 1666 A in this example) to be transmitted in the current frame. The header 1662 may also include a MAC address. MAC PDU 1660 includes the MUX indicator 1662, a possible local MUX PDU 1664 at the beginning (left from the previous configuration), followed by zero or more complete MUX PDUs 1666A-N, and a possible local MUX PDU 1668 (From the current configuration) or other padding used to fill the configured portion of the entity layer. MAC PDU 1660 is carried in the physical layer burst that has been configured for the MAC ID. Thus, the exemplary MAC PDU 1660 illustrates a transmission (or frame in accordance with 802.11 specific terminology) that can be transmitted from one STA to another STA, which includes a portion of the data directed to the destination STA. With the selective use of local MUX PDUs, high-efficiency packaging can be achieved. At a time indicated in the combined poll contained in the CCH, each MAC PDU can be transmitted in a TXOP (using 802.1 1 terminology). The exemplary embodiments detailed in Figures 15 to 16 illustrate various aspects, including merged polling, reduced transmission of leading items, and continuous transmission from each 96852.doc -40- 200527846 STA (including AP) The solid layer bursts to exclude gaps. They are applicable to any MAC system, including 802.1 1 system. The following further details alternative embodiments based on explaining other technologies to achieve MAC efficiency, and also supports peer-to-peer transmission, and integrates with and / or with existing legacy protocols or systems. As mentioned above, each of the specific embodiments detailed herein can use channel evaluation and strict rate control. Enhanced MAC efficiency can be achieved by minimizing unnecessary transmissions on the media, but in some cases, insufficient rate control feedback can reduce the overall throughput. Therefore, it provides ample opportunity for channel evaluation and feedback, thereby maximizing the transmission rate of all MIM0 modes, in order to prevent loss of throughput due to inadequate channel evaluation, which will offset any MAC efficiency gains. Therefore, as described above and described in the detailed description below, exemplary MAC embodiments may be designed to provide ample opportunity for transmission of the preamble and a chance for the receiver to provide rate control feedback to the transmitter. In one example, the AP periodically intersperses the MIM0 preamble in its transmission (at least every TP ms (milliseconds), where TP can be a fixed or variable parameter). Each STA can also use a MIMO preamble to start its polling τχ〇ρ, other §τα and AP can also use the MIM0 preamble to evaluate the channel. For transmissions to Ap or other STAs using a direct link protocol (described in further detail below), the MIMO preamble may be used to negotiate a steered reference that simplifies reception at the destination STA as a process. The AP may also provide opportunities to the destination STA, so that the destination STA may provide ACK feedback. The destination STA may also use their feedback opportunities to provide rate control feedback available to the transmitting STA in 96852.doc -41- 200527846 MIMO mode. Such rate control feedback is not defined in the old 8021 system (including 802.1 1 (e)). The use of MIMO can increase the amount of total rate control information (per MIM0 mode). In some cases, in order to maximize the improvement of MAC efficiency, it can be supplemented by strict rate control feedback. Another aspect used in this article (described in further detail below) is backlog information and STA scheduling. Each STA may start its TXOP with a leading term, followed by the duration of the next τχορ request. This asset was booked to AP. AP collects information about TXOPs from a request under several different STAs, and decides to allocate the duration of a subsequent TDD MAC frame interval on τχ〇ρ media. Aρ can use different priorities or QoS rules to decide how to share media, or it can use very simple rules to share media in a proportional manner according to the requirements from STAs. Any other scheduling technology can also be deployed. The TXOP configuration of the next TDD MAC frame interval is assigned in the subsequent control channel messages from the AP. Designated Access Points In the specific embodiment detailed herein, a network may support operation with or without suitable access points. When a suitable AP is present, the AP can be connected (for example) to a wired multi-pipe connection (ie, cable, fiber, DSL or T1 / T3, Ethernet) or a home entertainment server. In this case, the applicable AP may be the source or receiver of most of the data flowing between devices on the network. g / In the presence of applicable AP, stations can still use the decentralized coordination function (〇〇?), 802.1 113々 / & or 802.14 enhanced plastic 96852.doc • 42 · 200527846 decentralized channel storage as described above (Enhanced Distributed Channel Access) to communicate with other stations. As described in detail below, when additional resources are needed, a centralized scheduling mechanism can be used to achieve more efficient media use. For example, ‘this network architecture is formed in a home where many different devices must communicate with each other (ie, DVD_TV, CD-Amp-Speaker, etc.). In this case, the network station automatically designates a certain station to become Ap. Please note that the Adaptive Coordinati () n Function (ACF) can be used with a designated access point as described below, and can be used with centralized scheduling, random access, proprietary ( ad_hoc) communications or any combination thereof. Of course (but not necessarily), non-AP devices may have enhanced MAC capabilities and are suitable to operate as a designated AP. Please note that not all devices must be designed with the ability to specify an AP MAC. When Q0s (for example, guaranteed latency), high throughput, and / or efficiency are critical, one of the devices in the network must have a designated AP operating capability. This means that the specified AP capabilities are broadly related to devices with higher capabilities, such as having line power, a large number of antennas and / or transmit / receive keys, or high throughput requirements, etc.-or multiple attributes. (The additional factors for selecting a designated AP will be further detailed below). Therefore, low-end devices (for example, low-end cameras or phones) do not need to be negatively assigned AP capabilities, while high-end devices (for example, high-end video sources or high-definition video displays) can be equipped with AP capabilities. In a non-AP network, the designated Ap assumes the role of the applicable Ap, and may or may not have a reduced function. [In various embodiments, an AP specified by 96852.doc -43- 200527846 may perform the following items: (A) Establishing a Basic Service Set (BSS) ID; (b) Setting by transmitting a beacon signal (Beac〇n) & broadcast channel (BCH) network configuration information Network timing (bch can define the media combination until the next BCH); (c) use forward common control channel (FCCH) to schedule the transmission of stations on the network to manage the connection; ⑷ manage the correlation ( associati0n); ⑷ provides management control of QoS data flow; and / or ⑴ various other functions. The designated AP can implement a complex scheduler, or any type of scheduling algorithm. A simple scheduler can be deployed, examples are detailed below. The modified Physical Layer Convergence Protocol (PLCP) header for peer-to-peer communication is described below, which also applies to designated APs. In a specific embodiment, the basic data rate that can be decoded by all stations (including the designated AP) is used to transmit all transmitted PLCP headers. The pLCp header of the transmission from the station contains the receiver data accumulation (baeki0g) associated with-a given priority or data stream. Or, the PLCP header contains a follow-up to the __ given priority or data stream

Requirements for the duration of the transmission opportunity. S said that the AP can “snoop” (snooping) the PLCP headers transmitted by all stations to determine the storage duration of the station or station. Specify a load, collision, or other amount of IS to determine the time between day and day for the EDCA-style (distributed) access Z = and the time to be allocated to the contention-free polled (centralized) access Scoreable AP Executable-Basic scheduler for configuring bandwidth proportional to requirements ^ and scheduling their requirements during periods of no competition. Increment: 96852.doc -44- 200527846 Pai ^ was endorsed but not mandatory. The designated AP can announce a scheduled transmission on the CCH (Control Channel). A fixed AP may not need to respond (ech0) to the transmission of a certain station to other stations (ie, as a hop point), although this function is allowed. A suitable A? Convict has the ability to echo. When Yitian selects a designated access point, a hierarchical structure can be established to determine the appropriate: access point device. The non-consumption & factors that can be incorporated in the selection-designated access point include the following items: ⑷ user override; (b) higher preference setting level; ⑷ security level; ⑷ capability: line power; ⑷Capability antenna number 1; ⑴Capacity: maximum transmission function; (g) Disconnection according to other factors · Media access control (MAC) address; ⑻The first device is turned on; ⑴Any other factor. In practice, it would be desirable for the designated AP to be centrally located and have the best total Rx SNR CDF (i.e., to be able to receive all stations with satisfactory SNR). In general, the more antennas a station has, the more sensitive it is to receive. In addition, the designated AP can also have a higher transmission power, which promotes a large number of stations to know the designated AP. These attributes can be stored and utilized, thereby allowing the network to dynamically reconfigure as stations join and / or move around. 2. If the network configuration has an applicable Ap or a designated Ap, it can support peer-to-peer connection. The next section provides a general description of peering. In a specific embodiment, two types of peer-to-peer connections can be supported. (The peer-to-peer connection in the connection is where the AP schedules transmissions for each relevant station; and (b) the ad hoc connection, where the AP is not responsible for managing or scheduling the platform transfer 96852.doc -45- 200527846 input. The designated AP can set the MAC frame interval and transmit a beacon signal at the beginning of the frame. Broadcast and control channels can specify the configured duration of the frame for station transmission. For For stations that have requested a peer-to-peer transmission configuration (and the AP knows their requirements), the AP can provide scheduled configurations. The AP can announce these configurations in the control channel, for example, per MAC frame. The AP can also be selective The MAC frame includes an A-TCH (ad hoc) segment (described in further detail below). The presence of A-TCH in the MAC frame can be indicated in the BCH and FCCH. During the A-TCH, the station can use CSMA / CA procedures to implement peer-to-peer communication. The CSMA / CA procedures in IEEE Wireless LAN Standard 802.1 1 can be modified to eliminate the need for immediate ACK. When a station seizes a channel, the station can transmit MAC-PDU (Protocol Data Unit) consisting of multiple LLC-PDUs The maximum duration that a station can occupy in the A-TCH can be indicated in the BCH. For the approved LLC, the window size and maximum approval delay can be negotiated according to the necessary application delay. The following will refer to Figure 20 for further details Describe a modified MAC frame with an A-TCH segment for use with applicable APs and designated APs. In a specific embodiment, an unsteered ΜΜΟ pilot can cause all Stations can know the channel between itself and the transmitting station. This can be very useful in some cases. In addition, designated APs can use non-manipulated MIMO preambles to allow channel evaluation and facilitate demodulation Derive the configured PCCH. Once the designated AP 96852.doc -46- 200527846 receives all required configurations in a given MAC frame, they can schedule their required configurations for subsequent MAC frames. Please note that The rate control information need not be included in the FCCH. In a specific embodiment, the scheduler performs the following tasks. First, the scheduler collects All required configuration of the MAC frame, and calculate the total required configuration (Total Requested). Second, the scheduler calculates the total resources that can be allocated to F-TCH and R-TCH (the total number of available resources ( Total Available)). Third, if the total number of requests (Total Requested) exceeds the total number of resources (Total Available), the configuration of all requirements will be adjusted proportionally according to the ratio of "Total Available" / "Total Requested" . Fourth, for any scaled configuration of less than 12 OFDM symbols, their configuration will be increased to 12 OFDM symbols (in this example, alternative parameters can be used to deploy alternative specific embodiments). Fifth, in order to accommodate their results in F-TCH + R-TCH, the configurations' can be configured one at a time in a cyclic (r0uncj-robin) manner starting from the maximum configuration, subtracting one symbol from all configurations larger than 12 OFDM symbols To accommodate any oversized OFDM symbols and / or alert periods. An example illustrates the specific embodiment described in the previous paragraph. Please consider the following configuration requirements: 20, 40, 12, 48. Therefore, "Total Requested" = 120. Assume that "Total Available" = 90 ° and then assume that the required alert period is 0.2 OFDM symbols. Then, as described in the third operation above, the scaled configuration is: 15, 30, 9, 36. As mentioned in the fourth operation above, the configuration with a value of 9 is increased to 12. According to the fifth operation, the revised configuration and alert time paragraph 96852.doc -47- 200527846 was added, with a total configuration of 93.8. This means that their configuration is reduced by 4 symbols. It is opened from the maximum configuration and one symbol is removed at a time to determine the final configuration of 14, 29, 12, 34 (i.e., a total of 89 symbols and 0 · 8 symbols for the guard period). In a non-standard embodiment, when a designated AP accesses, the AP may establish a beacon signal for the BSS and set the network timing. The device is associated with the designated AP. When two 1-devices associated with a specified Ap require a QoS connection (eg, a HDTV link with low latency and high throughput requirements), their devices will provide traffic specifications to the specified AP to For management control. The designated Ap may grant or deny the connection request. If media utilization is low enough, use CSMA / CA to set the overall media duration between beacon signals to be used by edca operations. If the EDCA is running smoothly (for example, without any excessive collisions, returns, and delays), the designated AP need not provide coordination functions. The designated AP can continue to monitor the media utilization by listening to the PLCp header transmitted by the station. Based on the observed media and the requirements of the backlog or transmission opportunity duration, the designated AP can determine when the EDCA operation does not meet the required QoS for the permitted data stream. For example, a given Ap can observe the reported backlog or trend over the required duration and compare the observed trend with the expected value based on the permitted data stream. When the designated AP determines that the necessary qo $ is not in accordance with the distributed access, the job on the media can be changed to use polling and scheduling. Polling and scheduling provide more deterministic delays and higher throughput efficiency. The following 96852.doc -48- 200527846 further details examples of such operations. Therefore, it is possible to deploy according to the observed media utilization, collision, congestion, and the transmission opportunity requirements from the transmitting party's station according to A ?, viewing, and compare their requirements with the permitted QoS data streams. Take the mechanism) adjustment to program (centralized) operation. As mentioned above, in any specific embodiment detailed in this specification, the access point has been described herein. Those skilled in the art should understand that the specific embodiment can be adjusted to configure an applicable access point or specify The access point works. As described in detail herein, designated access points may also be deployed and / or selected, and may operate in accordance with any agreement (including agreements not described in this specification or any combination of agreements). Peer-to-Peer Transmission and Direct Link Protocol (DLP) As mentioned above, peer-to-peer transmission allows a STA to directly transmit data to its STA 'without the need to first transmit data to an AP. The various aspects described in this article can be used in conjunction with peer-to-peer transmission. In a specific embodiment, the direct link agreement (DLP) can be adjusted as described in detail below. FIG. 17 illustrates an exemplary peer-to-peer communication within a system 100. In this example, the system 100 (which may be similar to the system shown in Figure 1 00) is adjusted to allow direct transmission from one UT to another UT at noon (in this example, the transmission between UT106A and UT106E is illustrated ). The UT 106 can perform any direct communication between the WLAN 120 and the AP 104, as described herein. In various exemplary embodiments, two types of peer-to-peer 96852.doc -49- 200527846 connections can be supported. (A) Manage peer-to-peer connections, where AP schedules transmissions for each relevant STA, and (B) Proprietary (ad hoc) connection, where Ap is not responsible for managing or scheduling STA output. A specific embodiment may include either or both types of wiring. In an exemplary embodiment, a portion of a transmitted signal may contain common information that can be received by one or more stations (possibly including access points), and include information for peer-to-peer receivers. The station receives specially formatted information. This common information can be used in scheduling operations (for example, as shown in Figure h), or it can be used for competitive back-ups by neighboring stations (for example, as shown in Figure 26). The various exemplary embodiments described below illustrate closed loop rate control for peer-to-peer connections. Such rate control can be deployed to take advantage of available South data rates. Based on a clear discussion, it is not necessary to detail each function (i.e., 'recognition') in this exemplary embodiment. Those skilled in the art should understand that the functions disclosed herein can be combined in various embodiments to form any number and set or sub-set. FIG. 18 illustrates the prior art entity layer burst 1800. A leading item 1810 may be transmitted, followed by a physical layer convergence protocol (plcp) header 1820. The old 802.11 system defined a PLCP header to include the rate type and modulation format of the data transmitted as the data symbol 1830. FIG. 19 illustrates an exemplary entity layer burst 1900 that can be deployed for peer-to-peer communication. As shown in FIG. 18, a leading item 1810 and a Fan (:: 1> header 1820 may be included, followed by a pair of equation transmissions (labeled P2p 194〇). P2p 1940 may include a MI19 preamble 1910 for the receiver υτ use. May include 96852.doc -50- 200527846 ΜΙΜΟ rate feedback 1920 for future transmission of receiving * υτ back to the transmitter υτ. Rate feedback can be generated in response to _ from the receiver's station to the transmitter The previous transmission of the station. The data symbols can be transmitted at the rate and modulation format selected for the peer-to-peer connection. 丨 93. Please note that a physical layer cluster (for example, a burst of 190) can cooperate with the AP Managed peer-to-peer connections can be used together with proprietary peer-to-peer transmission. Specific examples of non-uniform rate feedback are described below. The following also provides alternative bulk transmissions that include their aspects Specific embodiment. In an exemplary embodiment, an AP sets the TDD MAC frame interval. Broadcast and control channels can be deployed to specify the duration configured in the TDD MAC frame interval. Equivalent transmission of STAs (and APs know their requirements), APs can provide scheduled configurations, and announce these configurations in the control channel every TDD MAC frame interval. The exemplary has been described in detail with reference to FIG. 15 Fig. 20 shows an exemplary embodiment of a TDD MAC frame interval 2000 including optional proprietary segments (identified by A-TCH 2010). The role of similarly numbered sections in the TDD MAC frame interval 2000 Substantially the same effect as the section described above with reference to Figure 15. Can be used in Bch 510 and / or

CCH 520 indicates that A-TCH 2010 exists in the TDD MAC frame interval 2000. During A-TCH 2010, stations may use any competitive procedure to perform peer-to-peer communication. For example, 802.11 technologies such as SIFS, DIFS, return, etc. can be deployed as described above. QoS technologies may be selectively deployed, such as those employed in 802.1 (e) (i.e., AIFS). Various other competing mechanisms can also be deployed. 96852.doc -51- 200527846 In an exemplary embodiment, the CSMA / CA program used for competition (such as the program defined in 802.11) may be modified as follows. No immediate ACK is required. When a STA acquires a channel, the STA may transmit a MAC protocol data unit (MAC-PDU) composed of multiple PDUs (ie, LLC-PDUs). The maximum duration that a STA can occupy in the A-TCH can be indicated in the BCH. When an acknowledged transmission is required, the window size and maximum acknowledgement delay can be negotiated according to the necessary application delay. In this example, F-TCH 530 is part of the TDD MAC frame interval used for transmission from AP to STA. Peer-to-peer communication between STAs using competing technologies can be implemented in a-TCH 2010. Scheduled peer-to-peer communication between STAs can be implemented in r-Tch 540. Any segment in their segment can be transmitted as a null value. FIG. 21 illustrates an exemplary physical layer burst 2100 (also referred to as a "PHY burst"). PHY Burst 2 100 can be deployed with a programmatic peer-to-peer connection, for example, during R-TCH 540, or during A-TCH 2010's proprietary connection, as described above with reference to Figure 20. The PHY burst 2 100 may include a non-controllable MIMO preamble 2110, a Peer Common Control Channel (PCCH) 2120, and one or more data symbols 2130. The unmanned MIMO preamble 2110 may be received at one or more stations, and a receiving station may use the unmanned MIMO preamble 2110 to evaluate respective channels between the non-transmitting station and the receiving station. This exemplary PCCH includes the following fields: (a) —Destination MAC-ID; (b) —Configuration requirements for requesting the duration of the desired transmission at the next TDD MAC frame interval; (c) A transmission rate indicator , Used to indicate the current data 96852.doc -52- 200527846 packet transmission format; (d) —control channel (ie, CCH) subchannel for receiving any configuration from the AP; and (e) a CRC. pccH 212〇 together with the non-manipulable ΜΜΟ preamble 2110 is a common segment receivable by each listening station (including the access point). A configuration requirement may be inserted in the pCCH to allow a management peer connection in a future TDD MAC frame interval. Such PHY bursts can be included in a proprietary connection and still require a scheduled peer configuration in a future TDD MAC frame interval. In this exemplary embodiment, the preamble of the non-manipulative MIM 0 is eight. 0)? 1)] ^ (in the alternative embodiment described below, fewer symbols may be sufficient for channel evaluation) And the PCCH is two OFDM symbols. Use the spatial multiplexing and / or higher modulation format determined by each STA in the peer-to-peer connection 'after this common segment (including the non-manipulable MIM〇 preamble 2 丨 丨 〇 and PCCH 2120) followed by one or Multiple data symbols 213. This part of the wheel is coded according to the rate control information in the data section that is being transmitted later. Therefore, a part of the 2100 bursts can be received by multiple surrounding stations' while the actual data transmission is adjusted for efficient transmission to one or more specific peer-connected stations or Aps. The data in data symbol 2 丨 30 can be transmitted according to the configuration of an access point, and the data in data symbol 2130 can be transmitted according to a dedicated connection (that is, a 'CSMA / CA competitive procedure). An exemplary embodiment of a PHY burst includes a leading term consisting of 8 non-manipulated MIMO symbols referenced. It uses STTD mode and is coded with R = 1/2 BPSK, and includes a peer-to-peer common control channel (PCCH) MAC-PDU header in the next 2 OFDM symbols. The MAC-ID is 12 96852.doc -53- 200527846 bits. Includes an 8-bit configuration request for AP reception to request the desired transmission duration during the next TDD MAC frame interval. τχ (transmission rate) is 16 bits and is used to indicate the transmission rate currently used in the packet. The FCCH sub-channel preference setting is 2 bits, which corresponds to the preference setting between up to four sub-channels. Ap should make any applicable configuration according to this setting. The CRC is 10 bits. Any number of other fields and field sizes may be included in the alternative ρ 替代 γ burst specific embodiment. In this example, the remainder of the MAC-PDU transmission uses the spatial multiplexing and / or higher modulation determined by each STA in the peer-to-peer connection. This part of the transmission is encoded in accordance with the rate control information embedded in the data part of the transmission. FIG. 22 illustrates an exemplary method 2200 for peer-to-peer data transmission. The program starts at step 2210, where a station transmits a non-manipulating MIM0 preamble. In step ㈣, the station transmissions can be decoded together. For example, the non-manipulated MIM0 preamble 2110 and pcCH 212〇 are examples of mechanisms used to request configuration in official connections. Stations in Ap or other schedules must be able to decode the signal portion that includes the request. Familiar with this: Technicians should understand that there are many alternative requirements mechanisms that are suitable for scheduling peer-to-peer connections on a shared channel. In step ㈣, the data will be transferred from one station to another in accordance with the negotiated transmission format. In this example, maneuvering data is transmitted using a rate determined by the measurement of the non-manipulating M-lead 211G. Those who are familiar with this technology should understand that various alternative means of transmission resources can be adjusted to m-deterministic equivalent channels. 'Figure 23 illustrates an exemplary method for peer-to-peer data communication. 2968968.doc -54- 200527846 This exemplary method 2300 illustrates several aspects, which can be deployed in any given embodiment. Subset. The program starts with decision steps 23-10. In decision step 23 10, if there is data for STA-STA transmission, go to step 2320. If no data is available, proceed to step 2370 and perform any type of communication, including other access types (if any). Proceed to decision step 2360, where the procedure can be repeated by returning to decision steps 23 10, or the procedure can be stopped. In decision step 2320, if there is STA-STA data to be transmitted, it is determined whether the peer-to-peer connection is already scheduled or proprietary. If the transmission is to be scheduled, the process proceeds to step 2330 and requires a configuration to win the TXOP. Please note that a configuration request may be made during the random access portion of the TDD MAC frame interval (as described above) or may be included in a proprietary transmission. Once configured, a STA-STA entity burst can be transmitted in step 2350. In an exemplary embodiment, method 2200 can be regarded as a type of STA-STA PHY burst. In decision step 2320, if the scheduled peer connection is not the desired connection, then proceed to step 2340 to compete for access. For example, a TDD MAC frame interval of 2000 A-TCH 20 10 segments can be used. When the access has been successfully won through contention, it proceeds to step 2320 and transmits a STA-STA PHY burst, as described above. From step 2350 to decision step 2360, the procedure can be repeated (as described above) or the procedure can be stopped. FIG. 24 illustrates an exemplary method 2400 for providing rate feedback for use in a peer-to-peer connection. This illustration shows the various transmissions and other steps that can be performed by two stations (STA 1 and STA 2) 96852.doc -55- 200527846. STA 1 transmits an unsteered pilot 2410 to STA 2. STA 2 measures channel 2420 while receiving a non-managing preamble 24 10. In an exemplary embodiment, STA 2 determines a supported transmission rate on the channel according to the measurement. The transmission rate decision is transmitted to STA 1 as rate feedback 2430. In various alternative embodiments, substitute parameters may be derived to allow rate feedback decisions to be made at the STA office. At 2440, STA 1 receives a scheduled configuration or competes for a transmission opportunity during, for example, A-TCH. Once a transmission opportunity has been obtained, at 2450, STA 1 transmits data to S D A 2 according to the rate and modulation format determined by the response rate feedback 243. The method shown in Figure 24 is universal and applicable to specific embodiments, as known to those skilled in the art. Some examples of incorporating peer-to-peer rate feedback are detailed below, as well as other aspects. Figure 25 shows the method for managing the material connection between two stations (STA am and —Access Point (AP). At step 005, STA i transmits a non-manipulating preamble and _ Configuration requirements. Data can be transmitted in accordance with an earlier configuration and previous rate feedback, as described below. In addition, it can be in accordance with the rate feedback from a previous-type peer-to-peer connection, or from STA1 or a proprietary starting with 2 The rate feedback of the communication is used to transmit any such lean materials. The non-manipulating preamble and transmission requirements are received by sta 2 and the access point (and can be received by other stations in the area). Access point wiring transmission requirements And, one of the _ Shuang Banzong snoring bee Ding ”silent queen of the spear king to determine the date, and whether to perform peer-to-peer communication configuration in step 2505 transmission of non-manipulating preamble Measure the channel and determine the supported rate for peer-to-peer communication with STA 1. 96852.doc -56- 200527846 2 2 It is also possible to selectively receive the rate feedback and / Or data. In this example, the access point has decided to The request transmission is performed with a configuration. At step 2515, a configuration is transmitted from the access point to STA 1. In this example, the configuration is transmitted on r_tch 540 during the control channel (eg, CCH 52〇), as above In the same way, in step MM, R-TCH configuration is performed for STA 2. In step 2525, STA i receives the configuration from the access point. In step 2530, STA 2 receives the configuration from the access point. In step 2545, STA 2 transmits the rate feedback according to the configuration in step 2520. As described above, it may optionally include a scheduled transmission request, and may also include any data to be transmitted according to a previous request. Follow step 25 10 In the channel measurement, the transmission rate feedback is selected. The ρΗγ burst of step hw may further include a non-smart control preamble. In step 1, the channel from STA 2 is measured, the rate feedback is received, and the selected data can also be received. In step 2545, the configuration in step 25 15 is known, and STA 1 transmits data according to the received rate feedback information. In addition, it can also provide future configuration requirements and rates according to the measurement in step 2540. Feed. The data used for peer-to-peer communication is transmitted in accordance with the specified channel test. In the step, STA2 receives the data and any selective transmission rate feedback. 3 Ding2 can also measure the channel to provide for future transmission Please note that the transmissions in steps 2535 and 2545 can be received by the access point at 96852.doc -57- 200527846, at least the non-controlling part, as described above. Because, for any included requirements The access point can perform additional configurations for future transmissions, as shown in configurations 2555 and 2560 for STA 1 and STA 2, respectively. At steps 2565 and 25 70, STA 1 and STA 2 receive their corresponding configurations. Then, as the access point manages access to the shared media, and STA i and STA 2 directly transmit peer-to-peer communication with each other using the rate and modulation format selected by the supportable capabilities on the peer-to-peer channel, without periodic repetitions This procedure. Note that in an alternative embodiment, proprietary peer-to-peer communication can also be performed in conjunction with managed peer-to-peer communication as shown in FIG. Figure 26 illustrates a competitive (or ad hoc) peer-to-peer connection. STA i and STA 2 will communicate with each other. Other STAs may also be in range and have access to the shared channel. At step 2610, STA 1 (with the lean material to be transmitted to STA 2) monitors and competes for access to the shared channel. Once a transmission opportunity has been won, the peer PHY burst (step 2615) is transmitted to STA 2, and other STAs may also receive the burst. At step 2620, other STAs (that are monitoring the shared channel) will receive transmissions from STA 1 and know to avoid accessing that channel. For example, a PCCH (as described above) may be included in the transmission (step 2615). At step 2630, STA 2 measures the channel 'according to a non-controlling preamble and competes for backhaul access on the shared channel. STA 2 can also transmit data (if required). Please note that competition time will change. For example, in the 802.1 1 system, an ACK can be returned after SIFS. Since slFs has the highest priority, STA 2 can respond without losing channels. Specific embodiments may allow for shorter delays and may provide high priority for returning data. 96852.doc -58- 200527846 In step 2635, the STA 2 transmits the rate feedback and selected data to §τα 1. At step 2640, STA 1 receives the rate feedback, competes for access to the common channel again, and transmits to STA 2 according to the received rate feedback at step 2645. At step 2640, STA 1 also measures the channel to provide rate feedback for STA 2 for future transmissions, and can receive any optional data transmitted by STA 2. In step 2650, STA 2 receives the data transmitted in step 2645 according to the rate and modulation determined by the measured channel conditions. STA 2 may also receive rate feedback for transmitting a transmission back to STA 1. STA 2 can also measure channels' to provide future rate feedback. Therefore, this procedure can be repeated by returning to step 2635 ′ so that STA 2 returns the rate feedback and data. Therefore, two stations can perform bidirectional proprietary operations through contention access. By using rate feedback and adjusting the transmission to the receiving station, the peer-to-peer connection itself is made efficient. When one of the pHY bursts is co-receivable, then, as shown in step 2620, other STAs can access the information and can avoid interfering with the channel when the known channel is occupied, as shown in pccH. As in FIG. 25, prior to the steps shown in FIG. 26, managed peer-to-peer communication or proprietary peer-to-peer communication can initiate data transfer and can then be used to continue peer-to-peer communication. Therefore, any combination of scheduling and proprietary peer-to-peer communication can be deployed. FIG. 27 illustrates an exemplary TDD MAC frame interval of 2700 to illustrate management peer-to-peer communication between stations. In this example, f_tch & A_TCH durations are all set to zero. The beacon signal (BeaCon) / BCH 510 & CCH 520 is transmitted as described above. The beacon signal (Bac0n) / Bc II 96852.doc -59- 200527846 560 indicates the start of the next frame. CCH 52〇 indicates a peer-to-peer communication configuration. According to their configuration, STA 1 transmits to STA 2 in the configured burst 2710. Note that in the same TDD MAC frame interval, the segment 2730 used to respond to STA 1 is allocated to STA 2. Any given peer-to-peer PHY layer burst may include any of the components described above, such as rate feedback, requests, manipulative and / or non-manipulating preambles, and manipulating and / or non-manipulating data. STA 3 transmits to STA 4 in configuration 2720. In a similar manner, STA 4 transmits to STA 3 in configuration 2740. R-TCii can include various other reverse link transmissions, including non-equivalent connections. The following will further detail additional exemplary embodiments for explaining them and other aspects. Example 0 Please note that in FIG. 27, a guard interval can be scheduled between segments if necessary. A key issue with peer-to-peer communication is that the path delay between STAs is unknown. One method to deal with this problem is that each STA, ′ supports its transmission time to be constant, and promotes to reach the AP in a synchronous manner with the A clock. In this case, Ap can provide guard periods at both ends of each peer configuration to compensate for the path delay between the STAs in the two communications. In many cases, a cyclic preflx is sufficient and no adjustments are required at the STA receiver. Next, sta must determine their respective time offsets in order to know when to receive the transmission of the other lights. STA reception must maintain two receiving clocks: Pulses are used for peer-to-peer connections. As described in the above specific embodiments, the receiver may derive approval and channel feedback during its configuration period & and return to a transmitter. Even if the osteosynthesis 96852.doc -60- 200527846 traffic flow is one-way, the receiver will still send the reference and request to get the configuration. The AP scheduler ensures that sufficient resources are provided for feedback. Compatible with legacy stations and access points As described herein, the specific embodiments described provide improved solutions to legacy systems. However, assuming extensively deployed legacy systems already exist, a system may want to maintain backward compatibility with existing legacy systems and / or legacy user terminals. In this article, the term "new category" is used to distinguish "old system". A new category system may include one or more aspects or functions detailed hereinb. An exemplary embodiment of the new class system is the MIMO OFDM system detailed below with reference to FIGS. H-52. In addition, the patterns detailed below for merging a new category system with an old system are also applicable to other systems, and whether or not this system includes any special improvements detailed in this article will still be deployed. In one exemplary embodiment, retrospective compatibility with alternative systems can be provided by using separate frequency assignments (Frequency ASsignment; FA), thereby allowing separation from legacy users? You may want to deploy an AP as a multi-carrier system. Therefore, a new category system can search for available FAs for its operation. It can be implemented in a new class of WLANs—Dynamic Frequency Selection Frequency SeleCtlon; DFS) algorithm ’to provide frequency search. Legacy STAs that are trying to access WLANs can use two scanning methods, passive and active. Paragraph in order to develop a bit order. Using Active Scanning and Passive Scanning, STAs can perform basic service set (BSS) cleansing by scanning operations near them, and the STA transmits a query to solicit information from other STAs in 96852.doc -61- 200527846 BSS Respond. Old standards do not provide poor information on how STAs decide which BSS to join, but once a decision has been made, correlation can be tried. If unsuccessful, the STA will move through its BSS list until it succeeds. When an old STA does not know the transmitted beacon signal information, it should not try to establish association with a new class of WLAN. However, a new class AP (and UT) can ignore the requirements from the old STA as a method for maintaining a single Wlan class on a single FA. An alternative technique is that a new class AP or a new class STA uses a valid old (ie, 802.1 1) message to reject any old StA request. If the legacy system supports such messaging, a redirect message can be provided for the legacy STA. A significant trade-off related to the use of separate FAs is the additional spectrum required to support the two types of STAs. One advantage is that it is easy to manage different WLANs while maintaining functions such as q0s. However, as described in the detailed description of this specification, for supporting high data rates of new types of systems (for example, the specific embodiment of the MIM0 system detailed herein), the old csma mac protocol (for example, the old 802 1 1 Agreements detailed in standards) are often inefficient. Therefore, it is desirable to deploy backtracking compatible operation modes, thereby allowing a new MAC to coexist with the old MAC on the same FA. In the following, several exemplary embodiments of the old system, 'first-new, and other systems that can share the same fa are detailed. FIG. 28 illustrates a method 2800 for supporting legacy stations and new-type stations on the same frequency assignment. In this example, for the sake of clarity, it is assumed that it operates in an isolated state of 96852.doc -62- 200527846 (ie, there is no coordination between multiple overlapping BSSs). The process starts at steps 28 to 10, where the old signal is used to build a race-free period. Next, we will illustrate several illustrative examples for use with the old 802.1 1 system, in which the new class WLAN AP can use the built-in interceptor (Hook) in the old 802.1 1 standard to reserve for exclusive use by new class stations time. In addition to their signaling technologies, any number of signaling technologies can be used to build a competition-free period for any type of legacy system. One technology is the establishment of a competition-free period (CFP) in the PCF / HCF model. The AP can set up a beacon interval and declare a contention-free period during the beacon interval. The AP can poll the new class and the old one in a polling mode during this period STA. This will cause all older STAs to set their network configuration vector (NAV), which is a counter used to continuously track the CFP, to the duration of the declared CFP. As a result, the old STA receiving the beacon signal during the CFP period is prevented from using the channel until it is polled by the AP. Another technique is to establish a CFP via RTS / CTS and duration / ID fields, and set NAV. In this case, the new class AP can send out a special RTS with a Reserved Address (RA), which is used to indicate to all new class STAs that the AP is reserving a channel. The old STA interpreted this RA bit as directing to a specific STA and did not respond. The new category STA responds with a special CTS to clear the BSS during the period specified in the duration / ID field of the RTS / CTS message pair. At this time, the new category station can use the channel freely without conflict for the duration of the 96852.doc -63- 200527846 reservation. At step 2820, the old-type STA that has received a signal to build a contention-free period waits until the polling or contention-free period ends. Therefore, the access point has successfully configured shared media to work with the new class of MAC protocols. In step 2830, the new STA can access in accordance with this agreement. In this new type of MAC protocol, various sets or sub-sets detailed in this paper can be deployed. For example, scheduled forward and reverse link transmissions can be deployed, as well as managed peer-to-peer transmissions, proprietary or competitive communications (including peer-to-peer), or any combination of the foregoing. At step 2840, the new category access period is terminated using any of a variety of signal types (varies depending on the legacy system deployed). In this exemplary embodiment, the transmission-contention-free period ends. In the alternative embodiment, the old STA may also be polled during a contention-free period. Such access can take place after or be interspersed with new category access. In step 2850, if a contention period is defined for the legacy system, all STAs will access. This allows legacy systems that were unable to communicate during periods of money contention to make requests and / or attempt transmissions. Decision step 2860. The process may continue by returning to decision step 2810, or the process may stop. Figure 29 illustrates a combination of legacy and new categories of media access control. The upper part of the figure shows an old MAC agreement 2910 and a new type agreement 2930. When combined, it constitutes a MAC agreement such as the combined MAC agreement 2950. In this example, the 802.U legacy signal is used for illustrative purposes. Those skilled in the art should understand that the techniques disclosed herein are applicable to any of various legacy systems and any new types of MAC protocols, including any combination of the functions disclosed herein. 96852.doc -64- 200527846 Legacy 280 protocol 2910 includes a beacon signal (Beacon) 2902 for identifying beacon signals (^^ (: 〇11) time interval. The legacy beacon signal (Beacon) time The interval includes a non-competition period 2904, followed by a competition period 2906. During this non-competition period 2904, various non-competition polls 2908 AN may be generated. The non-competition period 2904 is terminated by ending the non-competition period 29 10. In 802.1 1 exemplary specific In the embodiment, each beacon signal (Beacon) 2902 is transmitted at a Target Beacon Transmission Time (TBTT). The new class agreement 2930 includes a MAC frame 2932A-N 0 Beacon time Interval 2950 illustrates the interoperability of the old and new class MAC protocols during the contention-free period 2904. Includes the new class TDD MAC frame interval 2932, followed by the old polling CF poll 2908A-N. By UPEND (no contention End of the period) 2910 to end the non-competition period, followed by the competition period 2906. The new category TDD MAC frame interval 2932 may be of any type, including optional details detailed in this article In an exemplary embodiment, the new class TDD MAC frame interval 2932 includes various sections, such as the sections described with reference to FIG. 20. Therefore, in this example, the new class TDD MAC frame interval 2932 includes: a preamble signal (pilot) 510, a control channel 520, a forward transmission channel 530, a proprietary peer-to-peer section (A-TCH) 2010, a reverse link transmission channel 540, and a random storage Take channel 550.

Please note that during CFP 2904, legacy STAs should not interfere with any new category of WLAN transmissions. The AP can poll any legacy STAs during the CFP, allowing mixed mode operation on the segment. In addition, the AP can retain the entire CFP 96852.doc -65- 200527846 2904 for the new category 'and push all the old traffic into the competition period (cp) 29〇6 near the end of the beacon time interval . Exemplary legacy 802.H data requires a length of CP2906 sufficient to support the exchange between two legacy peer-to-peer transmissions. As a result, the beacon signal may be delayed and the system time may be unstable.) If desired, to mitigate instability, the CFP interval can be shortened to maintain a fixed beacon interval. The leaf timers used to build ⑽ and ^ can be set to promote a long period of CFP (i.e., about leap seconds) relative to CP (i.e., less than 10 milliseconds). However, during the cFp, if the AP polls the old terminals, the transmission duration of their old terminals may be unknown and cause extra time. As a result, when STAs are sold on the same W-nano, 'the puppet of the new category sta must be maintained with great care. The old 802. " standard synchronization is called the ⑽ millisecond time unit (Tlme Unit. Called. The new type of MAC can be designed to synchronize with the old system. Here, we will use 2 TU or 2.48ms The duration of the MAC frame. In the same specific embodiment, you may want to ensure that the new type of MM frame is the same. That is, the clock frame of the conventional MAC frame may be continuous, and when the frame boundary of the second frame is at 2 · The beginning of the frame time interval of 48ms. In this method, it is' easy to maintain the STA's eye-breaking mode. The new category transmission does not need to be compatible with the old transmission. Header and preamble: both can be used by the new category system. Unique, detailed description in this manual. Sale: You can try to demodulate these items, but they will not be decoded correctly. STAs in the sleep mode are usually not affected. Master solution Figure 30 shows a kind of The method used to win the transmission opportunity side. The method 96852.doc -66- 200527846 method 3000 can be deployed as step 2830 in the exemplary embodiment of method 2800, as described above. The procedure starts with the decision step Starting from 3〇〇, access in this step can be a schedule Non-programming. Those skilled in the art should understand that although this example illustrates two types of access, in any given embodiment, one or both of them can be supported. In decision v 3 In 010, if non-programmable access is desired, proceed to step 3040 to compete for access. Any number of competing access technologies can be deployed. Once the TXOP has been naked, in step 3050, Transmission is performed according to the transmission opportunity. Then the program stops. In step '3 01 〇, if program access is desired, proceed to step 3020 to request access. During a proprietary competition, on a random access channel Make this access request, or any other technique disclosed herein. At step 3030, when a pre-access request is received, a configuration is received. Proceed to step 3 050 'Transfer τχ〇ρ according to the received configuration. In In some cases, it may be desirable to accommodate interoperability between a newly awarded AP (and its associated Bss) and an overlapping old bss in the same frequency configuration. The old BSS may be tied to 0 (: 17 Or 1 > (: 17/11 ( 17 mode, it will not always be possible to achieve synchronization between the new class BSS and the old bss. If the old BSS is operating in the PCF4HCF mode, the new class Ap can: try to synchronize with TBTT. If synchronization can be implemented, the new category Ap can use any of various mechanisms (examples of which have been described before) to obtain the frequency during competition ¥ to operate in the Kidz® BSS area. If the old BSS is in DCF mode Operation, the new category Ap can also try to get the channel and declare 96852.doc -67- 200527846 channel one CFP to clear the transmission of some or all STAs in the old BSS that did not receive the new category AP transmission. In this case, the old WLAN will ship you 9 to any new category. In order to avoid this interference, the new type of CSMA operation is sighed as ^ and relies on the temple transmission (the following will be described in detail with reference to @ 33 至 图 34). + Exemplary method for not sharing multiple BSS_single fa ^^. A beacon is transmitted at the old access point. A new class of access points assigned a total of the same frequency can be synchronized to the beacon signal associated with τττ (optional). In step 3120, if an old or non-competition period has been designated based on the M-signal (Beacon), the non-competition period will be implemented. Once the contention-free period (if any) has been completed, all STAs will compete for access during a designated contention period. At step 3, the 130 胄 class access point competes for access during the competitive period. At step the new category STA can access the shared media during the new category access point has been competing for access. The type of access during this new category of access can include any aspect detailed herein. Various techniques (such as those described above) can be used to indicate to the legacy STAs the amount of time the access point reserves the channel. Once this period has reached a certain level, in step 3150, the old STAs can compete. Decision step 3 1 60, # 王 序 can continue by returning to decision step 3 丨 丨 〇, or the program stops 0 Figure 32 Edge does not use an overlapping BSS of a single FA. The legacy system 3210 transmits ^ Beacon 3205 (3205A and 3205B are shown in the figure to illustrate the TBTT of the legacy system and the entire beacon signal interval). The beacon 96852.doc -68- 200527846 signal (Beacon) 3205A identifies the non-competition period 3210 and the competition period 3215. During the no-competition period 3210, the old no-competition polling 3220A-N may be implemented, followed by an indicator of the end of the no-competition period 3225. Stations in the new category WLAN 3240 monitor channels, receive beacons 3205, and cannot access media until a competing access opportunity arrives. In this example, the earliest opportunities were during periods of no competition. After PIFS 3230, the new class access point transmits an old signal 3245 to indicate to the old station the amount of time it will occupy the channel. Various symbols can be used to perform this function, as described in the example explained above. Various other signals can be deployed based on legacy systems that you want to interoperate with. Old STAs within the range of the old signal 3245 reception will avoid accessing the channel until the end of the new class access period 3250. The new class access period 3250 includes one or more TDD MAC frame intervals 3260 (3260A-N in this example). The TDD MAC frame interval 3260 may be of any type. Examples include one or more of the various aspects detailed herein. In an exemplary embodiment, the new category AP fetches channels at time intervals (i.e., the AP fetches channels for up to 20 milliseconds every 40 milliseconds). New class APs can maintain a timer to ensure that channels are held only for the desired duration, thereby ensuring fair channel sharing. In the process of acquiring channels, the new class AP can use various signaling technologies. For example, CTS / RTS or legacy beacon signals (Beacon) used to announce a new CFP may be transmitted. During the new class time interval 3250, an exemplary TDD MAC frame interval can be defined in the following ways: First, a beacon signal is transmitted plus F-CCH, which is used to indicate the desired MAC frame in the current MAC frame. Polling list UT on 96852.doc -69- 200527846. After the F-CCH, a MIMO lead stretch is broadcast to allow the STA to acquire and build an accurate measurement of the MIMO channel. In an exemplary embodiment, excellent performance is achieved for every 2 short OFDM symbols transmitted. This means that the F-TCH in the initial MAC frame may consist of approximately 8 MIMO preamble symbols. The R-TCH part of the first MAC frame can be structured to prompt the STAs on the polling list to return the controllable MIMO preamble and an approved (download link) rate indicator to AP. In this example, all terminals on the polling list are now ready to operate in the normal schedule during the next TDD MAC frame interval. The TDD MAC frame interval following the first TDD MAC frame interval can then be used to exchange data, which is coordinated by the AP using any of the techniques disclosed herein. As mentioned above, in some cases (for example, when some or all of the STAs in the old BSS did not receive AP transmissions of the new category), the stations of the new category may be preset to operate in CSMA mode and rely on peer-to-peer transmission. In such cases, the on / off cycle described above may not be helpful or even feasible. In these cases, the new category of stations can default to peer-to-peer operation. FIG. 33 illustrates an exemplary method 3300 that uses the techniques disclosed herein to perform high-speed peer-to-peer communication while interoperating with an old BSS. The procedure starts at step 3310, where the first STA with data to be transmitted to the second STA competes for access. At step 3320, the access has been successfully contested, and the station uses an old signal (the old signal as described above) to empty the media. In step 3330, the first STA transmits a request (with the same preamble) to the second STA. The second STA can measure the channel according to the transmitted preamble. 96852.doc -70- 200527846 The second STA transmits a channel feedback to the first STA. Therefore, in step 3340, the first station receives a response including channel feedback. In step 3350, the first STA transmits preamble and manipulation data to the second station according to the feedback. At step 3360, the second STA may transmit the acknowledgement to the first STA and may transmit continuous rate feedback for use in future transmissions. Legacy signals used to empty media Allow steps to implement steps 3330 to 3360 using any high-speed technology and improvements to legacy systems (for example, the technology and improvements disclosed herein). Once a STA has emptied the media, any peer MAC agreement can be deployed, which is within the scope of the present invention. The program returns as shown in decision step 3370. Step 33 10 continues, or the program stops. In an exemplary embodiment, using the peer-to-peer mode, the fetch channels operate according to the old rules of CSMA. In this example, PCF and HCF are not used and may not necessarily be a centralized network architecture. When a new category STA wants to communicate with another new category STA (or AP), the STA fetches the channel. The first transmission consists of a sufficient MIMO preamble plus a message for requesting a connection. CTS and RTS can be used to clear the area and retention time. The requesting STA message must include the STA BSS ID, STA MAC ID, and target STA MAC ID (if known). The response shall include the BSS ID of the responding STA. This allows the STA to decide if it is necessary to perform receiver correction of the transmission steering vector, if steering has been used. Please note that it is not necessary to use transmission control in this case. However, if all STAs have been calibrated to a designated AP of a protocol BSS, the use of transmission control will be helpful. As described with reference to FIG. 33, a response may include a MIMO preamble (operate 96852.doc-71-200527846, if used) plus a rate indication. Once this exchange has occurred, manipulation on each link is feasible. However, if the STAs belong to different BSSs, the first manipulation transmission between the STAs in the initial connection may include a manipulated MIMO preamble, thereby allowing the receiver of the responding STA to correct the phase difference between different BSSs. In this exemplary embodiment, once the initial exchange has occurred, control is possible. This exchange shall observe the SIFS time interval between the download link transmission and the upload link transmission. Because of the potential processing delay in calculating the feature vectors for manipulation, STAs will be required to use Minimum Mean Squared Erro (MMSE) processing instead of feature vector processing. Once the steering vector has been calculated, the STA can start using the steering vector at the transmitting end and continue to use MMSE processing at the receiving end, with the optimal spatial matched filter scheme as the adjustment target. With periodic feedback between two STAs, tracking and rate control can be facilitated. The SIFS time interval can be respected, thereby enabling the STA to maintain channel control. Figure 34 illustrates peer-to-peer communication using MIMO technology over legacy BSS with contention access (i.e., unmanaged). In this example, the originator station 106A competes for access to the channel. When the originating station 106A has successfully acquired the channel, the MIMO preamble 3405 is transmitted, followed by the transmission request 3410. The message may include the BSS ID, the originating STA MAC ID, and the target STA MAC ID (if known). Other signals can be used to clear the channel further, such as CTS and RTS. The responder STA 106B transmits the pilot preamble 3420, and then transmits the acknowledgement and rate feedback 3425. SIFS 3415 after request 3410, transmission controlled pilot 3420. In this exemplary implementation, 96852.doc -72- 200527846, the old access point is an 802.1 1 access point. Remember that SIFS is the highest priority, so the responder station 106B will maintain channel control. The transmissions shown in Figure 34 may be SIFS transmitted separately from each other, thereby maintaining channel control until peer-to-peer communication is complete. In an exemplary embodiment, a maximum duration of channel occupation may be determined. After the rate feedback 3425, according to the rate feedback, the steerable preamble 3430 and data 3435 are transmitted from the initiator STA 106A to the responder STA 106B. After the data 3435, the responder STA 106B transmits the controlled preamble 3440 and the acknowledgement and rate feedback 3445. The response from the originator STA 106A was a transmission-controlled preamble 3450, followed by transmission of data 3455. Depending on the deployment period, this process can continue from time to time or up to the maximum time allowed for channel access. Not shown in Figure 34, the responder STA can also transmit data, and the originating station can also transmit rate control. These data fragments may be combined with the data fragments shown in Fig. 34, thereby maximizing the efficiency (i.e., no SIFS need to be interspersed between them). When two or more BSSs overlap, it may be desirable to deploy a mechanism to allow channels to be shared in a coordinated manner. The following is an overview of several exemplary mechanisms and exemplary operating procedures associated with each. They can be deployed in combination. The first exemplary mechanism is dynamic frequency selection (DFS). Prior to the establishment of BSS, WLAN may be required to search for wireless media to determine the optimal frequency allocation (Frequency Allocation; FA) for BSS operation. In the process of searching for candidate FAs, an AP can also establish a neighbor list to facilitate redirection and handover between APs. In addition, WLAN can synchronize MAC frame 96852.doc -73- 200527846 timing and neighbor BBS (explained in detail below). DFS can be used to distribute BSS to minimize the need for synchronization between BSS. The second exemplary mechanism is inter-BSS synchronization. During the DFS procedure, an AP can obtain the timing of the neighbor BSS. In general, it may be desirable to synchronize all BSSs (in a specific embodiment, on a single FA; in another embodiment, to access multiple FAs) to facilitate inter-BSS handovers. However, with this technology, BSSs that are at least very close to each other and use the same FA will synchronize their MAC frames. In addition, if the common channel BSS overlaps (that is, the APs can learn about each other), the newly arrived AP can warn the existing APs of its existence and establish a resource sharing agreement, as described below. The third exemplary mechanism is the resource sharing protocol. BSSs overlapping on the same FA share the channel fairly. Equivalent channel sharing can be achieved by alternating MAC frames between BSSs in a defined manner. This allows traffic in each BSS to use the channel without the risk of interference from neighboring BSSs. All overlapping BSSs are shared. For example, there are 2 overlapping BSSs, one AP. Uses an even MAC frame, and the other APs use an odd MAC. With 3 overlapping BSSs, modulo-3 common operations can be performed and so on. Alternative embodiments may be implemented with any type of sharing mechanism. The control field in the BCH add-on message indicates whether resource sharing is enabled and the type of sharing cycle. In this example, the timing of all STAs in the BSS is adjusted to an appropriate shared cycle. In this example, the delay will increase due to overlapping BSS. The fourth exemplary mechanism is STA assisted re- 96852.doc -74- 200527846 synchronization. The two BSSs may not know each other, but the new STAs in the overlapping area will know the two BSSs. The STA may determine the timing of and report to the two BSSs. In addition, the STA can also determine the time offset and indicate which AP should adjust its frame timing and adjustment amount. This information must be propagated to all BSSs connected to the AP, and their BSS must re-establish the frame timing to achieve synchronization. Frame synchronization can be announced in BCH. Algorithms can be generalized to handle more unknown overlapping BSS. Exemplary procedures are detailed above and may be deployed in one or more of the mechanisms described in the previous paragraph. The AP can perform synchronization at power-on or at other specified times. The system timing can be determined by searching all FAs near the system. To facilitate synchronization, a set of orthogonal codes can be used to help distinguish different APs. For example, the AP knows the beacon signal repeated every MAC frame. Such beacon signals (Beacon) can be masked using a Walsh sequence (eg, a length of 16). Therefore, a device (eg, AP or STA) can perform Pilot Strength Measurement (PSM) of the regional AP to determine the overlapping BSS. The following will further explain in detail, in the role associated with an AP, the STA can transmit an echo to assist synchronization. The echo can use tuning and covering corresponding to the covert of the AP. Therefore, if the BSS overlaps, but the APs corresponding to their BSS cannot detect the signal from the other party, a neighboring AP can receive an STA echo to provide information about its AP and provide a neighbor AP synchronizable signals. Please note that 96852.doc -75- 200527846 orthogonal hidden coding can be reused on different FAs. The choice of Walsh concealment can be done deterministically based on undetected Walsh concealed sets (ie, selecting undetected waish concealment on nearby Ap). If all concealment is present, the new AP can reuse the code corresponding to the lowest received signal level (Receivec [Signai Level; RSL). Otherwise, in a specific embodiment, the coding for maximizing the Ap operating point may be selected (refer to the structured power return for adjusting reuse, as described below). In this example, the frame counters transmitted by each AP are staggered relative to each other. The staggered arrangement used corresponds to the Walsh covert index. Therefore, AP0 uses Walsh coding. Apj uses Walsh to conceal j, and whenever the AP0 frame counter, its frame counter is equal to zero. When turning on or performing synchronization at any time, Ap will listen to the nearby AiMf signal (Beacon) and / or STA response (ech〇). After the neighboring system is not detected, the AP establishes its own time reference. This time reference may be any time reference, or related to GPS, or any other local time reference: After detecting a single system, the regional timing will be established accordingly. If two or more systems operating with different timelines are detected, Ap can be synchronized with M with the strongest signal. If their systems use the same frequency assignment (FA), APs can attempt to correlate to the weaker eight and know that independent clocks are used nearby. New: Taste: Γ: The AP notification is synchronized with the timing error adjustment required for their two AP regions. The AP next to the 'weaker region' can adjust its timing error. This operation can be repeated for multiple repeats Αρ. New APs can use their synchronization—or two or more systems—to synchronize 96852.doc -76- 200527846 to establish their timing. In the case where all neighboring APs cannot (for any reason) be synchronized to a single timing, the new AP can be synchronized to any neighboring AP. The AP can perform dynamic frequency selection at power-on. As mentioned above, it is often desirable to use DFS selection to minimize BSS overlap, thereby minimizing the number of BSSs that need to be synchronized, and to minimize any delays or throughput reductions that may be associated with synchronization (ie, saving on a FA The BSi of the entire media may be more efficient than a BSS that must share the media with one or more neighboring BSSs). After synchronization, the new Ap can choose the FA with the smallest RSL associated (i.e., when the neighboring AP is measured, or at the echo time). The AP may periodically query whether the STA has an AP preamble measurement. Similarly, the AP may schedule a silent period to enable the AP to evaluate the level of interference caused by STAs from other regions (ie, neighboring BSS). If the RSL level is too high, 'the AP may try to find other fas at unscheduled times, and / or establish a power return principle, as described above. As described above, the APs can be organized according to a leading cover code. In this example, each AP can use a Walsh sequence cover with a length of six. Any number of encodings of various lengths can be deployed. Leader concealment (pil0tcover) is used to modulate the beacon signal with a sign of ⑶ ... during a superframe period. In this example, the superframe period is equal to 32 milliseconds (i.e., 16 consecutive MAC frame beacon signals (Beacon)). Then, the STA can integrate the superframe time interval in a coherent manner, thereby determining the preamble power associated with a given Ap. As mentioned above, an AP can select 96852.doc -77- 200527846 Walsh code from the available undetected Wald code pool. If all codes have been detected (on the same fa), ap can sort their codes in the strongest to weakest order. The AP can reuse Walsh codes corresponding to the weakest Walsh codes detected. To facilitate the identification of neighboring APs, a response (ech0) may be transmitted by the STA to identify the corresponding AP. Therefore, as described above, an AP that does not detect neighboring APs can detect a corresponding STA echo to identify the AP and its timing in this way. Each AP can transmit its configuration information in its beacon signal 'and each STA can act as a repeater to retransmit the AP configuration information and timing to any receiver Party is near the AP. However, month b will request the active S TA (based on the command from the AP) to transmit a specified mode to allow nearby APs to use the same FA to detect the presence of neighboring systems. A simple way to facilitate this is to define an observation interval (ie, between the FCH and RCH segments) in the MAC frame that the non-AP uses to transmit any traffic. The length of the duration of this observation interval can be defined to be sufficient to handle the maximum differential propagation delay between the STA associated with the AP and the STA associated with the neighboring AP (e.g., 16 chips or 2 OFDM symbols). For example, an STA associated with an AP using the waish covert code j may transmit its echo whenever the MAC frame counter == 0. The response is encoded using the information needed to allow neighboring APs to detect STAs accessed in the relevant AP area and coexist with them efficiently. 〇 Structured power that can be deployed for regulated reuse return. When a system must reuse each FA near another AP to become congested, it may be possible to use 96852.doc -78- 200527846 to use a structured power fallback mechanism to allow terminals in both zones to operate at maximum efficiency . When congestion is detected, power control can be used to improve system efficiency. That is, the AP can use a structured power bounce mechanism that is synchronized with its MAC frame counter instead of using full power transmission for the entire time. For example, suppose two APs are using the same FA. Once the AP detects this condition, the two parties can develop a known power return principle. For example, both APs use a fallback mechanism to allow full power Ptot in MAC frame 0, power Ptot (15/16) in MAC frame 1, ..., power Ptot / 16 in MAC frame 15. Since their APs are synchronized and their frame counters are staggered, it is not possible to use full power at the same time in any AP area. The goal is to choose a fallback mode that allows STAs in each AP zone to operate with the highest possible throughput. The bounce mode used by a given AP may be a function of the degree of interference detected. In this example, a given AP can use up to 16 known return modes. The AP may carry the bounce mode in the BCH and the echo in the echo transmitted by the STA associated with an AP.

An exemplary return mechanism is detailed in U.S. Patent No. 6,493,33 1 entitled "Method and apparatus for controlling transmissions of a communications systems" filed by Walton et al., Which has been assigned to the assignee of the present invention people. Figure 53 illustrates another exemplary embodiment of a technique for interoperating with legacy systems. An exemplary MAC frame 1500 is shown in the figure, as described above with reference to FIG. 15. A time slot mode is used, which defines 96852.doc -79- 200527846 time slot intervals. The slot time interval 53 10 includes a MIMO lead time interval 53 15 and the slot time interval 5320. As shown, multiple preambles 5315 are inserted, thereby preserving channels from interference from other stations (including APs) operating in accordance with rules (e.g., EDCA). The modified MAC frame 5330 essentially includes the MAC frame 1500 and multiple preambles 5315 inserted to maintain media control. Figure 53 is for illustration only, as known to those skilled in the art. The time slot mode can be combined with any type of MAC frame, and various examples have been described in this article. In this example, for the purpose of explanation, it is assumed that the MAC frame used by an old 802 · 丨 丨 system is a multiple of 1204 milliseconds. The MAC frame can be set to 2.048 milliseconds to be synchronized. At the target pilot signal transmission time (tbtt), an announcement of the CFP duration causes the STA to set its own NAV. During this CFP, STAs in the BSS should not transmit until they are polled. As mentioned above, ap can selectively transmit an RTS, and STA responds (ech0) with the same cts, thereby further clearing the BSS. This CTS may be a synchronized pass from all stas. In this example, instability can be ruled out by ensuring that the MAC frame always starts at the 2.048 millisecond boundary. Even using the BTTT, which is shortened by see-through, this approach still maintains time synchronization between adjacent / overlapping BBSs. Various other technologies (for example, the technologies described above) can be combined with the technologies described below. Once the media has been reserved for repairing the AC box 5 3 30, any available technology can be used to deploy it to maintain the occupied media, thereby preventing old STAs from interfering with the scheduled, large, and potential Reduce the round-trip gain of new category systems (that is, systems that use the mechanism shown in Figure 5 or Figure Η, or various other systems detailed in this article). 96852.doc -80- 200527846 In this example, the new category AP fetches the channel according to CSMA rules. However, before that, the new category ^ should try to determine whether there are other secrets by listening to beacon signals (howling or other STA's. However, {requires synchronization of 4 daggers to allow fair resource sharing. Once proximity has been detected BSS, the new class AP can get the channel by transmitting its beacon signal. In order to block other uses, the new_AP uses -frequency to transmit the preamble to prevent others from using the channel (ie, no Any idle period greater than PIFS = 25 microseconds.) A new class AP can set a timer to allow it to occupy the channel for a fixed and fixed duration that is determined to be fair. This may be roughly synchronized with the beacon signal of the old AP (Beacon) Epoch or asynchronous (i.e. _ milliseconds per millisecond). New class APs can fetch channels at any point during the allowed time interval. This may be delayed by older BSS users. If there is no to be servoed Traffic 'means that the new category Ap can give up the channel before the time limit expires. When the new category AP gains access to the channel, it has the use limit of a fair period of time. Another day when the new category AP is established The sequence can be matched with the established mac frame. However, the sequence of the new class beacon signal (Beacon) will occur on the 2 millisecond boundary of the AP clock of the new class. In this way, the STA of the new class can check The day-to-day interval is used to determine whether Ητ Ap has taken the channel, so that synchronization can be maintained. The new AP can announce its frame parameters in the beacon signal. Beam parameters section It can include the preamble time interval to indicate the preamble transmission frequency of the entire 96852.doc -81- 200527846 MAC frames. Please note that the new class Ap can schedule STAs, causing the transmission of other STAs to overlap with periodic bursts. Preamble. In this case, the STAs assigned overlap will learn about this condition and ignore the preamble during this period. Other STAs do not know this condition, so they will use a threshold two tester to ensure whether there is a specified interval. Transmission preamble. A feasible approach is that an STA can transmit a shovel at the moment when the AP is authorized to transmit, or the AP is transmitting a controlled preamble at this time interval. In order to prevent other STAs from using the preamble, its channel evaluation is wrong The preamble can use Walsh concealment orthogonal to the common preamble Walsh concealment. A structure for assigning Walsh concealment can be deployed. For example, when STA and Ap use different Walsh concealment, Walsh space can include 2N concealment, where N One concealment is reserved for ap, and the other concealment is reserved for STAs associated with a given AP. The concealment used by their STAs is coupled to the corresponding Walsh concealment in a known manner. When a new class of AP transmits an assignment to an STA, , It expects that the STA will perform backhaul transmission at the specified time interval. The STA may not be able to receive the assignment, in which case, the channel may be in an unused complaint during a time interval longer than the PIFS. To prevent this from happening, Ap can sense the channel during t < siFS and decide whether the channel is occupied. If the channel is not occupied ’, the AP can immediately take the channel by transmitting the preamble and phase it accordingly. New category channel assignments may be time-slotted into SIFS intervals (16 cents). This guarantees channel occupancy, thereby blocking old users during the period of exclusive use of the new category. Since the duration of the RCH will exceed 16 microseconds, the RCH must be set to 96852.doc -82- 200527846 to account for interoperability. In a given embodiment, if the RCH is difficult to adapt, when the new class MAC does not have channel control, the RCH can be configured to operate in the old mode (that is, coexist in the old mode). As shown in Figure 53, by allowing the STA to transmit an access request at any time after a preamble transmission (that is, waiting for 4 microseconds and transmitting during 8 microseconds), F-RCH can be adapted.

Exemplary embodiments: Enhanced 802.1 1 MIMO WLAN Exemplary embodiments are described below to explain various aspects and additional aspects introduced above. In this example, an enhanced 802.1 1 WLAN using MIMO is illustrated. Each MAC enhancement scheme will be detailed, and the corresponding data and signal structure used in the MAC layer and the physical layer will also be detailed. Those familiar with this technology should understand that only an illustrative subset of WLAN functionality is disclosed and it is easy to adapt the teachings in this article to match the interoperability of 802.1 1 legacy systems, as well as interoperability with other systems. The exemplary embodiments detailed below are characterized by interoperability with legacy 802.1 1a, 802.llg STAs, and interoperability with 802.lie drafts and expected final standards. The exemplary embodiment includes a MIMO OFDM AP, this name is to distinguish the old AP. As mentioned above, legacy STAs should be associated with a retrospective compatibility due to retrospective compatibility. However, the MIMO OFDM AP can explicitly reject the association request from an old STA, if so. The DFS procedure can direct rejected STAs to other APs (may be old APs or other MIMO OFDM APs) that support legacy operations 〇ΜΙΜΟ OFDM STAs can be associated with an 802.1 1a or 802.1 1g 96852.doc -83- 200527846 BSS, or associated BSS (Independent BSS; IBSS) without AP. Therefore, for such operations, STA will implement all mandatory functions of 802.1 1a, 802.11 g, and the expected final draft of 802.lie. When the old RF channel is shared with the MIMO OFDM STA, various functions are supported in the BSS or IBSS. The proposed MIMO PHY spectrum mask is compatible with the existing 802.11a, 802.11g spectrum masks, so no additional adjacent channel interference is introduced into the old STAs. The extended SIGNAL field in the PLCP header (explained below) is backwards compatible with the SIGNAL field in the old 802.11. The unused RATE value in the old SIGNAL field is set to define the new PPDU type (explained in detail below). The Adjusted Coordination Function (ACF) (explained in more detail below) allows any media to be shared arbitrarily between the legacy and MIMO OFDM STAs. According to the decision of the AP scheduler, 802.11e EDCA, 802.11e CAP, and SCAP periods (described below) can be arbitrarily interspersed in any beacon signal interval. As mentioned above, a high-efficiency MAC is required. In order to make full use of the high data rate enabled by the MIMO WLAN physical layer with high efficiency. The attributes of this exemplary MAC are explained in detail below. The following are several exemplary attributes: PHY rate and transmission mode adjustments make efficient use of the capacity of the MIMO channel. PU's low-latency service provides low-end-to-end latency to meet the needs of high-throughput (eg, multimedia) applications. Low-latency operation can be achieved by using competitive MAC technology under low load, or using centralized or decentralized scheduling in high-load systems. Low latency provides many advantages. For example, 96852.doc -84- 200527846 For example, low latency allows fast rate adjustment to maximize the data rate of the physical layer. Low latency allows the use of small buffers to implement low-cost MAc implementations without stalling ARQ. Low latency also minimizes end-to-end delays and is suitable for multimedia and high throughput applications. Another attribute is the high MAC efficiency and low contention add-on. In a competitive MAC, at high data rates, the time taken for useful transmission is reduced, and the incremental fraction of that time is consumed in additional terms, collisions, and idle periods. By scheduling, and by aggregating multiple higher-level packets (for example, IP data elements) into a single MAC frame, you can reduce wasted media time. A summary frame can also be formed to minimize the preamble and training overhead. The high data rate enabled by the PHY allows simplified qos processing. The exemplary mac enhancements detailed below are designed to address the aforementioned performance criteria in a way that is backward compatible with 802.11g and 802.11a. In addition, it also supports and improves the functions contained in the draft standard 8023 le (as described above), including functions such as TX0P and Direct Link Protocol (DLp), as well as the optional Block Ack mechanism. In the exemplary embodiments described below, new terminology will be used for certain concepts introduced previously. A comparison of the new terminology is detailed in Table 丨. °° 96852.doc -85- 200527846 Table 1: Comparison of specific terms

The wording used in the pre-terms of the earlier term is compared to the word used in the post-new term. MUX PDU or MPDU MAC frame Local MPDU MAC frame fragment MAC PDU PPDU Broadcast channel information (BCH) and control channel information ( CCH) SCHED message Control channel message Sub-channel SCHJ message CTRLJ fragment TDD MAC frame interval Schedule access period (SCAP) F-TCH (forward traffic channel) Schedule AP-STA transmission R-TCH (reverse traffic channel ) Program STA-AP or STA-STA transmit A-TCH (proprietary peer-to-peer traffic channel) protected EDCA or MIMO OFDM EDCA PCCH (peer-to-peer control channel) PLCP header SIGNAL field RCH FRACH flexible frame summary In this exemplary embodiment, flexible frame aggregation is facilitated. Figure 35 shows the packaging of one or more mac frames (or fragments) within a summary frame. Frame aggregation allows the encapsulation of one or more MAC frames (or fragments) 35 10 within a summary frame W, which may include header compression 'as described below. In summary 96852.doc -86- 200527846 乂 80 frame 3520 can be transmitted as a single? ? 〇11? 3011 3 53 0. The aggregate frame 3520 may include an encapsulated frame (or fragment) 35 10 of type data (management or control). When privacy is enabled, the frame packet bearer can be encrypted. The MAC frame header of an encrypted frame is transmitted "in a non-hazardous manner". As stated in the description just now, this MAC-level frame aggregation allows transmission of frames containing zero IFS or BIFS (Burst Interframe Spacing), which will be explained in more detail below) to the same recipient STA. In some applications, it may be desirable to allow the AP to transmit frames with zero IFS to multiple receiver STAs. This is permitted by using the SCBED frame described below. The SCBED frame defines the start time of multiple TXOPs. When the AP performs back-to-back transmission to multiple receiver STAs, it can exclude leading items and IFS. This is called PPDU aggregation, which distinguishes MAC-level frame aggregation. An exemplary aggregated MAC frame transmission (ie, a PPDU) starts with a preamble, followed by a MIMO PLCP header (including a SIGNAL field, which can include two fields SIGNAL1 and SIGNAL2), This is followed by MEMO OFDM training symbols (if any). Hereinafter, an exemplary PPDU format will be described in detail with reference to FIGS. 49 to 52. The aggregate MAC frame flexibly aggregates one or more encapsulated frames or fragments to be transmitted to the same recipient STA. (SCHED messages (explained in more detail below) allow summary TXOPs transmitted from the AP to multiple receiver STAs). There are no restrictions on the number of frames and clips that can be aggregated. There may be a limit on the maximum size of the summary frame built through negotiation. In general, the first and last frames in the summary frame 96852.doc -87- 200527846 may be fragments created based on high-efficiency packaging. When an aggregated frame contains several encapsulated data frames, the MAC header of the data and QoS data frames can be compressed, as described below. The transmitting MAC can try to minimize ρΗγ and PLCP add-ons and idle periods by using flexible frame aggregation. The way to achieve this is to aggregate the frames together to exclude inter-frame spacing and pLcp headers, as well as flexible frame fragments, thereby completely occupying the available space in a τχ〇ρ. In one exemplary technique, the MAC first calculates the number of octets to be provided to ρΗγ based on the current data rate and the duration of the assigned or competitive τχορ. Then, a complete and divided MAC frame can be encapsulated, thereby occupying the entire TX0P. If a complete frame cannot be accommodated in the remaining space in a TXOP, the MAC can split the next frame in order to occupy as much as possible the remaining octets in τχ〇ρ. Frames can be arbitrarily divided for high-efficiency packaging purposes. In an exemplary embodiment, this arbitrary segmentation is subject to a limit of a maximum of 16 segments per frame. This limitation may not be necessary in alternative embodiments. The remaining fragments of the MAC frame can be transmitted in subsequent τχ〇ρ. In subsequent TX0Ps, the MAC may grant higher priority to segments of frames that are not completely transmitted. Insert a summary header (2 octets in this example, described in more detail below) into the frame header that is inserted into the frame (or fragment) of each package. A length block in the summary header indicates the length (in octets) of the encapsulated MAc Λ box, and the receiver uses that length field to retrieve the frame from the summary frame (and Fragment). The recommended 96852.doc -88- 200527846 PPDU size field in the SIGNAL field provides the size of the MIMO PPDU transmission (the number of OFDM symbols), and at the same time, the summary header indicates the size of each encapsulated MAC frame. Length in octets. Header Compression of the Encapsulated Frame Figure 36 shows an old MAC frame 3600, which includes the MAC header 3660, followed by a frame body 3650 (which may contain a variable number of N octets) and a Frame Check Symbol (卩 € 3) 365 5 (4 octets in this example). This prior art MAC frame format is detailed in 802.1 1. The MAC header 3660 includes a frame control field 3610 (2 octets), a duration / ID field 3615 (2 octets), and a sequence control block 3635 (2 octets). Group) and a QoS control field 3645 (2 octets). In addition, there are four address fields: Address 1 3620, Address 2 3625, Address 3 3630, and Address 4 3640 (6 octets each). These processor addresses are also referred to as TA, RA, SA, and DA, respectively. TA is the address of the transmitting station. RA is the receiver station address. SA is the source station address. DA is the destination station address. When an aggregated frame contains several encapsulated data frames, the MAC header of the data and QoS data frames can be compressed. Figures 37 to 39 illustrate exemplary compressed MAC headers for QoS data frames. Note that FCS is calculated based on the compressed MAC header and (encrypted or unencrypted) packet bearer. As shown in Figures 37 to 39, when a MIMO Data PPDU (type 0000) is used to transmit a frame, a summary header field is introduced into the MAC header 3660 of the MAC frame 3600, thereby establishing an encapsulated MAC The frame, that is, 3705, 3805, or 3905, respectively. The 96852.doc -89- 200527846 MAC header containing the summary header field is called an extended MAC header (ie, 37000, 3800, or 3 900, respectively). One or more encapsulated management, control, and / or data frames (including QoS data) can be aggregated into an aggregate MAC frame. When data privacy is used, the packet bearer of the data or QoS data frame can be encrypted. For each frame (or segment) inserted in the summary frame (3705, 3805, or 3905, respectively), a summary header 3710 is inserted. Header compression is indicated by this aggregate header block, which is explained in more detail below. Data or Q〇s data Frame headers can be compressed to eliminate redundant fields. The summary frame 3705 shown in FIG. 37 shows an uncompressed frame containing all four addresses and duration / ID fields. After transmitting an uncompressed summary frame, the additional summary frame does not need to identify the transmitter and receiver station addresses (because they are identical). Therefore, address 1 3620 and address 2 3625 can be ignored. There is no need to include the duration / ID block 3615 for subsequent frames of the summary frame. NAV can be set using duration. The duration / ID field will be overlaid based on the content. In the polling message, the duration / ID field should include an Access ID (AID). In other messages, the duration / m field specifies the duration for setting the NAV. Figure 38 shows the corresponding frame 3805. When the source address and destination station address contain duplicate information, it can be further compressed. In this case, the address 3 363〇 and the address 4 3640 can also be removed to generate a frame 3905 shown in FIG. 39. When the field is removed, the receiver can insert the corresponding field (after decompression) from the previous header in the summary frame to understand the compression. In this example 96852.doc -90- 200527846, the first frame of a summary frame always uses the uncompressed header. The packet bearer may require header-based compression from the MAC header. Removed Certain stops. After decompressing the frame header, the decryption engine can obtain their blocks. The receiver uses this length stop to retrieve frames (and clips) from the summary frame. The length stop indicates the length (in octets) of the frame with the compressed header. After fetching, remove the summary header block. The decompressed frame is then passed to the decryption engine. During decryption, a stop in the mac header may be needed (uncompressed) based on the integrity of the message. FIG. 40 illustrates an exemplary summary header 3710. For one or more frames (encrypted or unencrypted) transmitted in a MIMQ Data PPDU, a summary header field is added to each frame (or fragment) header. The summary header includes a 2-bit Zhu Zhu total header type field 4 0 10 (used to indicate whether header compression and header compression type is used) and a 12-bit length 4040 . Type 00 frames do not use header compression. Frame 〇1 has been removed Duration / ID, Address 1 and Address 2 blocks. Like the type 0 frame, the type 10 frame has the duration / ID, address 1 and address 2 fields removed, and the address 3 and address 4 fields have been removed. The length block 4030 in the summary header indicates the length (in octets) of the frame containing the compressed header. 2 bits 4020 are reserved. Table 2 summarizes the summary header types. 96852.doc -91- 200527846 Table 2: Summary header types

In C, the establishment of relevance requirements, establishment of association responses, re-establishment of association requirements, re-establishment of association responses, probe requests, probe responses, de-association, authentication, and cancellation of authentication. The following control frames can be packaged in a summary frame together with the data frame: BlockAck & BlockAckRequcst. In alternative embodiments, any type of frame can be encapsulated. Adjustable Coordination Function The Adjustable Coordination Function (ACF) is an extension of HCCA and EDCA. It allows flexible, efficient and low-latency scheduling, and is suitable for operation with the high data rate enabled by Mim〇 PHY. FIG. 41 illustrates an exemplary embodiment of a Scheduled Access Period Frame (SCAP) used in the SCF. Using a SCHED message 4120, an AP can schedule one or more AP-STAs, STA-APs, or STA-STA TXOPs simultaneously during a so-called scheduled access period 4130. Their scheduled transmissions were identified by 96852.doc -92- 200527846 scheduled transmission 4140. This SCHED message 4120 is an alternative to the legacy HCCA polling described earlier. In this exemplary embodiment, the maximum allowed value of SCAP is 4 milliseconds. For illustrative purposes, FIG. 41 illustrates an exemplary scheduled transmission 4140, which includes AP to STA transmission 4142, STA to AP transmission 4144, and STA to STA transmission 4146. In this example, the AP is transmitted to STA B 4142A, then to STAD 4142B, and then to STAG 4142C. Note that since the source (AP) of each frame is the same, there is no need to introduce a gap between them τχορ. When the source changes, gaps are drawn between the TXOPs (exemplary gaps are explained in further detail below). In this paragraph, after AP to STA transmission 4142, STA C transmits to AP 4144A, then after a gap, STA G transmits to AP 4144B, and after a gap, STA E transmits to AP 4144C. Then schedule a pair of equations TXOP 4146. In this case, STA E is still the source (transmitted to STA F), so if the transmission power of STA E is not changed, it is not necessary to introduce a gap, otherwise a BIFS gap can be used. Additional STA-to-STA transmissions can be scheduled, but not shown in this example. Any TXOP combination can be scheduled in any order. The TXOP type sequence shown in the figure is merely exemplary convention. However, it may be desirable to schedule a TXOP to minimize the number of necessary gaps, but it is not mandatory. The scheduled access period 41 30 may also include a FRACH period 4150 (where a STA can make a configuration request) and / or a MIMO OFDM EDCA 4160 dedicated to Fast Random Access Channel (FRACH) transmission. Period (During this period, MIMO STA may use the EDCA procedure). Their competitive access periods are protected by SCAP's NAV designation 96852.doc -93- 200527846. During the MIMO EDCA 4160 period, MIMO STAs used EDCA procedures to access the media without competing with legacy STAs. Transmissions in any protected competition period use the MIMO PLCP header (described in further detail below). In this particular embodiment, 'AP does not provide TXOP scheduling during the protected competition period. When only MIM0 STA exists, the NAV of the SCAP can be set through a duration field of the SCHED frame (the SCHED frame will be explained in more detail below). Optionally, if it is protected by an old STA, JAP can add a CTS-to-Self 4110 before the SCHED frame 4120, thereby establishing a SCAP NAV at a STA in the BSS. In this specific embodiment, the MIMO STA adheres to the SCAP boundary. The last STA transmitted in a SCAP must terminate its TXOP for at least the PIFS duration before the end of the SCAP. The MIMO STA must also adhere to the scheduled TXOP boundary and complete its transmission before the end of the assigned TXOP. This allows subsequent scheduled STAs to start their TXOPs without sensing whether the channel is idle. SCHED message 4120 defines the schedule. TXOP (AP-STA, STA-AP, and / or STA-STA) assignments are included in the CTRLJ element (45 15-4530 in Figure 45, described in detail below) in the SCHED frame. This SCHED message can also define the SCAP 4100 part (if any) dedicated to FRACH 4150 and a protected part (if any) for EDCA operation 4160. If no scheduled TXOP assignment is included in the SCHED frame, the entire SCAP is set for EDCA transmission (including any FRACH) protected by the old STA through the NAV setting of the SCAP. 96852.doc -94- 200527846 The maximum length of a scheduled or competitive TXOP allowed during the SCAP may be indicated in an ACF capability element. In this specific embodiment, the SCAP length does not change during a beacon signal interval. The length can be indicated in this ACF capability element. An exemplary ACF element includes a SCAP length (10 bits), a maximum SCAP TXOP length (10 bits), a warning IFS (GIFS) duration (4 bits), and a FRACH response (4 bits) yuan). The SCAP length field indicates the SCAP length during the current beacon signal interval. The SCAP length field is coded in units of 4 microseconds. The maximum SCAP TXOP length field indicates the maximum allowable TXOP length during a SCAP. The maximum SCAP TXOP length field is encoded in units of 4 microseconds. The GIFS Duration field is the guard interval between consecutively scheduled STA TXOPs. The SCAP length field is coded in units of 800 nanoseconds. The FRACH response field is coded in units of SCAP. The AP must use a FRACH PPDU to respond to a received request. The response method is to provide the STA with a scheduled TXOP in the FRACH response SCAP. Figure 42 shows an example of how SCAP is used in conjunction with HCCA and EDCA. In any beacon time interval (beacon 4210A-C is shown in the figure), the AP is fully flexible and can use 802.1 1e CAP and MIMO SCAP to intersperse EDCA competitive storage in a regulated manner. Take duration. Therefore, using ACF, AP can operate as HCCA, but has the ability to configure the SCAP period. For example, the AP can use CFP and CP (like PCF) to configure a CAP for polling jobs (like HCCA — 96852.doc • 95-200527846), or it can configure a CAP for scheduled jobs. SCAP. As shown in Figure 42, during the beacon interval, the AP can use a combination of periods for contention-based access (BDCA) 4220A-F, CAP 4230A-F, and SCAP 4100A-I. (Based on simplification, the example in Figure 42 does not show any CFP). The AP adjusts the proportion of media occupied by different types of access mechanisms based on its scheduling algorithm and its observation of media occupation. Any scheduling technology can be deployed. The AP decides whether the permitted QoS data stream has been met and uses any other observations, including the measured media occupancy for adjustment. The foregoing describes HCCA and associated CAPs. Figure 42 shows an exemplary CAP 4230 for illustration. An AP TXOP 4232 is followed by a poll of the 4234A. HCCA TXOP 4236A is connected after a polling 4234A. Transmission of other polls 4234B followed by other respective HCCATXOP 4236B. EDCA has been described above. FIG. 42 illustrates an exemplary EDCA 4220 for illustration. Show various EDCA TXOPs 4222A-C. A CFP is omitted in this example. As shown in Figure 42, a SCAP 4100 may belong to the format detailed in Figure 41, including an optional (: Ding 3 1361, 4110, 30: 1 ^ 0 4120, and scheduled access period 4130. AP uses 802.11 A Delivery Traffic Indication Message (DTIM) is passed to indicate the scheduled tasks, as described below. The DTIM contains an access ID (AID) bitmap. Other APs in the AP or BSS have They access the accumulated data of ID. Use DTIM to notify all STAs with ΜΙΜΟ function to stay awake after the beacon signal. Both old and ΜΜΟ STAs have BSS 96852.doc -96- 200527846 In the middle, immediately after the beacon signal, the old STA will be scheduled first. After the old transmission, the SCHED message will be transmitted immediately to indicate the combination of scheduled access periods. In a specific scheduled access period Unscheduled MILM0-enabled STAs will sleep for the remainder of the SCAP and wake up to hear subsequent SCHED messages. Use ACF to enable various other modes of operation. Figure 43 illustrates an exemplary assignment, each of which letter The signal interval (Beacon) includes several SCAP 4100s interspersed with the contention-based access period 4220. This mode allows "fair" shared media, where MIMO data streams are scheduled during SCAP, and non-QoS data streams are Legacy STAs (if any) use the competition period together. Interspersed periods allow low-latency service MIMO and legacy STAs. As mentioned above, CTS-to-Self can be added before the SCHED message in SCAP to protect the old Yes STA. If there is no old STA, CTS-to-Self (or other old clear signal) is not needed. Beacon 4210 can set a long CFP to prevent any arrival during all SCAP periods The old STA. At the end of the beacon interval, a CP allows the newly arrived old STA to access the media.

The exemplary operation shown in FIG. 44 may be used to enable an optimized low-latency operation with a large number of MIMO STAs. In this example, it is assumed that the legacy STA (if any) requires only limited resources. The AP transmits a beacon signal and builds a long CFP 4410 and a short CP 4420. A beacon signal (Beacon) 4210 is followed by any broadcast / multicast message from the old STA. Then, multiple SCAPs 4100 are scheduled in a back-to-back manner. This operating mode also provides optimized power management because STA 96852.doc -97- 200527846 must periodically wake up to listen to SCHED messages, and if it is not currently scheduled in SCAP, it will sleep at the SCAP interval . Through 80 people? 4100 Scheduled Access Periods Included in 4130? 11 eight (: 11 or MILM EDCA period to provide protected competitive access for MILM STAs. Older STAs can obtain media competitive access during CP 4420. May be scheduled from AP immediately after transmitting a SCHED message Continuous scheduled transmission of SCHED frames with a leading item may be transmitted. AP transmission of subsequent schedules may be transmitted without a leading item (a leading item may be transmitted to indicate whether a leading item is included Instruction item.) An exemplary PLCP preamble is described in further detail below. In this exemplary embodiment, the scheduled STA transmission will begin with a preamble. Error recovery AP can use a packet that is suitable for receiving error recovery from SCHED. Various procedures. For example, if a STA cannot decode a SCHED message, it cannot use its TXOP. If a scheduled TXOP does not start at the assigned start time, the AP uses a packet after the unused scheduled TXOP starts. When the PIFS is transmitted, the recovery can be initiated. The AP can use the unused scheduled TXOP period as a CAP. During the CAP, the AP can transmit to one or more STAs. Polling a STA. The polling object may be the STA that missed the scheduled TXOP or other STAs. The CAP will be terminated before the next TXOP. When the scheduled TXOP is terminated early, the same procedure can be used. The AP can initiate recovery by transmitting at a PIFS after the end of the last TXOP in the scheduled TXOP. The AP can use the unused period of a scheduled TXOP as a CAP, as explained in the explanation just now 96852.doc -98- 200527846 Protected contention As mentioned above, a SCAP may also include a portion dedicated to FRACH transmission, and / or a portion of the IMSCA EDCA program may be used by them. Their competitive access periods may be Protected by SCAP's NAV setting. Protected contention assists AP with scheduling by allowing STAs to instruct TXOP requests to complement low-latency scheduling. During this protected EDCA period, MIMOM STAs can use EDCA-style access To transmit the frame (to prevent competition with the old STA). With the old technology, the STA can indicate the TXOP duration requirement or buffer status in the 802.11c QoS control field in the MAC header. However, FRACH is to provide A more efficient means of the same function. During the FRACH period, the MIMO STA uses a slot-like slot Aloha (slotted Aloha) to access channels in a fixed-size FRACH slot. FRACH PPDUs can include TXOP duration requirements. Demonstration here In a specific embodiment, the MIMO frame transmission uses a MIMO PLCP header, which will be described in detail below. Since the old 802.1 1b, 802.1 1a, and 802.11g STAs can only decode the SIGNAL1 field of the PLCP header (refer to Figure 50 for details below), in the presence of a non-MINO STA, the MIM frame must be in the Transmitted under protected conditions. When both old and MIMO STAs are present, STAs using the EDCA access procedure can use an old RTS / CTS sequence for protection. Legacy RTS / CTS indicates that the transmission uses the legacy preamble, PLCP header, and RTS / CTS frame in MAC frame format. MIMO transmission can also take advantage of the protection mechanism provided by 802_lle HCCA. Therefore, the Controlled Access Period (Controlled Access 96852.doc -99- 200527846

Period; CAP) to protect transmission from AP to STA, polling transmission from STA to AP, or transmission from STA to other STAs (using Direct Link Protocol (DLP)). The AP can also use the old CTS-to-Self to protect the MIMO Scheduled Access Period (SCAP) to prevent old STAs from accessing it. When an AP determines that all STAs in the BSS are able to decode the MIMO PLCP header, the decision result is indicated in the MIMO capability element in the beacon signal (Beacon). This is called MIMO BSS. In the MIMO BSS, according to the EDCA and HCCA, the frame transmission uses the MIMO PLCP header and the MIMO training symbol in accordance with the MIMO training symbol aging rule. Transmission in MIMO BSS uses MIMO PLCP. Shortening the Spacing Between Frames The techniques that have been widely used to shorten the spacing between frames have been detailed previously. In this exemplary embodiment, several examples of shortening the space between frames are explained. For scheduled transmissions, the start time of TXOP is indicated in the SCHED message. The transmitting STA can start its scheduled TXOP at the exact start time indicated in the SCHED message without having to decide whether the media is idle. As mentioned above, consecutively scheduled AP transmissions during a SCAP are transmitted without the minimum IFS. In this exemplary embodiment, a continuously scheduled AP transmission during a SCAP is transmitted under an IFS including at least Guard IFS (GIFS). The default value of GIFS is 800 nanoseconds. A larger value can be selected, at most it is the value of the next defined burst IFS (Bnrst IFS; BIFS). 96852.doc -100- 200527846 The value of GIFS can be indicated in this ACF functional element. Alternative embodiments may use any GIFS value and BIFS value. Successive MIMO OFDM PPDU transmissions (TXOP burst operations) from the same STA are separated by a BIFS. When using the 2.4 GHz band, BIFS is equal to 10 microseconds, and the MIMO OFDM PPDU does not include a 6 microsecond OFDM signal extension. When using the 5 GHz band, BIFS is 10 microseconds. In an alternative embodiment, BIFS can be set to a smaller or larger value, including zero. In order to allow the receiver STA's Automatic Gain Control (AGC) to switch between transmissions, a gap greater than 0 can be used when the transmission power of the transmitter's STA changes. Frames that require an immediate response from the receiving STA will not be transmitted using a MIMO OFDM PPDU. Instead, base legacy PPDUs are used for transmission, that is, Clause 19 in the 2.4 GHz band, or Clause 17 in the 5 GHz band. The following sections provide several examples of how to multiplex the legacy and MIMO OFDM PPDUs on the media. First, consider an old RTS / CTS, followed by a burst of MIMO OFDM PPDUs. The transmission sequence is as follows: old RTS-SIFS-old 0-3-SIFS-MIMO OFDM PPDU-BIFS-MIMO OFDM PPDU. In 2.4 GHz, legacy RTS or CTS PPDUs were extended using OFDM signals and SIFS was 10 microseconds. In 5 GHz, there is no OFDM extension, but SIFS is 16 microseconds. Second, consider an EDCA TXOP that uses MIMO OFDM PPDUs. The transmission sequence 歹 ij is as follows: ΜΙΜΟ OFDM PPDU-BIFS- Legacy BlockAckRequest-SIFS-ACK. Use the appropriate EDCA procedure of 96852.doc -101 · 200527846 (Access Class; AC) to obtain the EDCA TXOP. As mentioned above, EDCA defines access types that can use different parameters by AC, for example, AIFS [AC], CWmin [AC], and CWmax [AC]. The old BlockAckRequest was transmitted with signal extension or 16 microsecond SIFS. If a BlockAckRequest is transmitted in a summary frame within a MIMO OFDM PPDU, there is no ACK. Third, consider TXOP for continuous scheduling. The transmission sequence is as follows: STA A ΜΙΜΟ OFDM PPDU-GIFS-STA B ΜΙΜΟ OFDM PPDU. If the PPDU transmission is shorter than the assigned maximum grant TXOP, there may be a period of inactivity after the STA A MIMO PPDU. As described above, decoding and demodulating an OFDM transmission that has been encoded will cause the receiver STA to bear additional processing requirements. To accommodate this, 802.1la and 802.11g allow the receiving STA to have an extra period of time before having to transmit an ACK. In 802.1la, the SIFS time is set to 16 microseconds. In 802.llg, the SIFS time is set to 10 microseconds, but an extra 6 microsecond OFDM signal extension is introduced. Since decoding and demodulating MIMO transmission will cause more processing burden, a specific embodiment is designed to increase SIFS or OFDM signal extension according to the same logic, which will further reduce efficiency. In this exemplary embodiment, the Block ACK and Delayed Block ACK mechanisms of 802.11e are extended to eliminate the need for immediate ACK for all MIMO OFDM transmissions. If SIFS or OFDM signal extension is not increased, signal extension is excluded, and in many cases, the necessary inter-frame space between consecutive transmissions will be shortened or excluded, 96852.doc -102- 200527846 will lead to improved efficiency. SCHED message FIG. 45 shows the SCHED message described earlier with reference to FIG. 41 and will be described in further detail below. The SCHED message 4120 is a multiple polling message assigned to one or more AP-STA, STA-AP, or STA-STA TXOP during the duration of a scheduled access period (SCAP). The use of SCHED messages allows for reduced polling and competition for additional items, and also eliminates unnecessary IFS. SCHED message 4120 defines the SCAP schedule. The SCHED message 4120 includes a MAC header 4510 (15 octets in this exemplary embodiment). In this exemplary embodiment, the segments CTRL0, CTRL1, CTRL2, and CTRL3 (collectively referred to herein as CTRLJ, where J may be 0 to 3 to explain segments 451 5-4530, respectively) are all variable length, When present, it may transmit at 6, 12, 18, and 24 Mbps, respectively. Exemplary MAC header 4510 includes frame control 4535 (2 octets), duration 4540 (2 octets), BSSID 4545 (6 octets), power management 4550 (2 octets) Bytes) and MAP 4550 (3 octets). Block 4540 for the duration of bit 13-0 specifies the SCAP length (in microseconds). STAs with MIMO OFDM transmission function use duration block 4540 to set NAV for SCAP duration. When an old STA exists in the BSS, the AP can use other means to protect the SCAP, for example, an old CTS-to-Self. In this exemplary embodiment, the maximum value of SCAP is 4 milliseconds. The BSSID field 4545 identifies the AP. FIG. 46 illustrates a power management field 4550. The power management 4550 includes a SCHED count of 4610, a reserved field of 4620 (2 bits), a transmission power of 4630, and a reception power of 4640 at 96852.doc -103- 200527846. The AP transmit power and AP receive power are according to the instructions in the power management field, and the STA receive power bit criterion is measured at the STA. The SCHED count is a field that is incremented on each SCHED transmission (6 bits in this example). The SCHED count is reset when each beacon signal is transmitted. SCHED counting can be used based on various uses. For example, the following describes a power-saving feature that uses SCHED counting. The transmission power block 4630 indicates the transmission power level used by the AP. In this exemplary embodiment, the encoding method of the 4-bit transmission power field is as follows: the value indicates that the transmission power level is lower than the maximum value of the channel as indicated by the information element in the beacon signal 4 dB level of transmission power level (in dBm). The received power field 4640 indicates the expected received power level of the AP. In this exemplary embodiment, the encoding method of the 4-bit received power field is as follows: This value represents a 4 dB level of the received power level higher than the minimum receiver sensitivity level (-82 dBm). Based on the STA's received power level, the STA can calculate its transmission power level as follows: STA transmission power (dBm) = AP transmission power (dBm) + AP received power (dBm)-STA received power (dBm) 〇In In this exemplary embodiment, during the scheduled STA-STA transmission, the control segment is transmitted using a power level that can be decoded by both the AP and the receiving STA. The power control report from the AP, or the power control report from the power management field 4550 in the SCHED frame, allows the STA to determine the required transmission power level, so that the control segment can be decoded at the AP. This general aspect has been described in detail with reference to FIG. For a scheduled STA-STA transmission 96852.doc -104- 200527846, when the power required for decoding at the AP is different from the power required for decoding at the receiving STA, it will be compared at their power level. High power level to transmit PPDUs.

The MAP block 4555 shown in Figure 47 indicates that there is a protected contention access period and duration during the SCAP. The MAP stop 4555 includes the FRACH count 4710, the FRACH offset 4720, and the EDCA offset 4730. Exemplary FRACHff # 14710 (4 ^ it) ^: ^ FRACH ^ # * 4720 (10j® ^ yuan) The number of FRACH slots to start scheduling. Each FRACH slot is 28 microseconds. The '0' value of the FRACH count indicates that there is no FRACH period in the current scheduled access period. The EDCA offset 4730 is the beginning of the protected EDCA period. An exemplary EDCA offset 4730 is 10 bits. Both the FRACH offset 4720 and the EDCA offset 4730 are in units of 4 microseconds and start from the beginning of the SCHED frame transmission.

The SCHED message 4120 is transmitted as a special SCHED PPDU 5100 (type 0010), which will be described in further detail with reference to FIG. 51 below. SCHED message 4120 contains fragments CTRL0 45 15, CTRL1 4520, CTRL2 4525, and CTRL3 4530. The length of these fragments is indicated in the SIGNAL field (5 120 and 5 140) of the PLCP header of SCHED PPDU 5100. FIG. 48 shows a SCHED control frame for TXOP assignment. The CTRL0 4515, CTRL1 4520, CTRL2 4525, and CTRL3 4530 segments are all variable length, and each segment contains zero or more assigned elements (4820, 4840, 4860, and 4880, respectively). The CTRLJ segment uses a 16-bit FCS (in addition, it is 4830, 4850, 4870, and 4890) and 6 tail bits (not shown in the figure). For the CTRL0 fragment 4515, the MAC header 45 10 96852.doc -105- 200527846 and any CTRL0 assignment element 4820 are used to calculate the FCS (hence the MAC header shown in the figure is appended to the CTRL0 4515 in Figure 48). In this exemplary embodiment, FCS 4830 including CTRL0 4515 is still included even if no element is assigned in the CTRL0 fragment. As detailed herein, the AP transmits assignments for AP-STA, STA-AP, or STA-STA transmission in a SCHED frame. According to the instruction of the STA in the SCHED rate field of the PLCP header of the transmission, the assigned elements of different STAs are transmitted in a CTRLJ segment. Note that the robustness of CTRL0 to CTRL3 decreases. Each STA starts to decode the PLCP header of the SCHED PPDU. The SIGNAL field indicates the presence of CTRL0, CTRL1, CTRL2, and CTRL3 fragments and their length in the SCHED PPDU. The STA receiver starts by decoding the MAC header and the CTRL0 fragment, decodes each assigned element to the FCS, and continues to decode CTRL1, CTRL2, and CTRL3, stopping at the CTRLJ fragment whose FCS cannot be confirmed. Table 3 shows the five types of assignment elements defined. Several assigned elements can be encapsulated into each CTRLJ fragment. Each assignment element specifies the transmitting STA access ID (AID), the receiving STA AID, the start time of the scheduled TXOP, and the maximum permitted length of the scheduled T X Ο P. 96852.doc -106- 200527846 Table 3: Assigned element type (3 bits) Assigned element stop (length in bits) Total number (length in bits) 000 Single AP-STA Leading Item Presence (1) AID (16) Start offset (10) TXOP duration (10) 40 001 Single STA-AP AID (16) Start offset (10) TXOP duration (10) 39 010 Duplex AP- STA leading entry exists (1) AID (16) AP start offset (10) AP TXOP duration (10) STA start offset (10) STA TXOP duration (10) 60 011 A single STA-STA transmits AID (16) Receive AID (16) Start offset (10) Maximum PPDU size (10) 55 100 Duplex STA-STA AID 1 (16) AID 2 (16) STA 1 start offset (10) STA 1 max PPDU size (10) STA2 start offset (10) STA 2 maximum PPDU size (10) 75 The leading term can be excluded in continuous transmission from the AP. If the AP does not transmit a leading entry for a scheduled AP transmission, then the "leader entry exists" bit is set to zero. The advantage of excluding the leading example is that when the AP has a low-bandwidth, low-latency data stream to be transmitted to several STAs, for example, a voice over IP (VoIP) data stream with many 96852.doc -107- 200527846 BSS. Therefore, the SCHED message permits the aggregation of transmissions from the AP to multiple receiver STAs (ie, PPDU aggregation, as described above). Frame aggregation as defined above allows aggregation of frames to be transmitted to a receiving STA. The “Start Offset” field refers to the offset (in multiples of 4 microseconds) of the start time of the leading item of the SCHED message. AID is the access ID of the assigned STA. For all assigned element types (except the scheduled STA-STA), the TXOP Duration field is the maximum allowed length of the scheduled TXOP (in multiples of 4 microseconds). The actual PPDU size of the transmitted PPDU is indicated in the SIGNAL1 field of the PPDU (explained in further detail below). For scheduled STA-STA transmissions (assigned element types 011 and 100), the “Max PPDU Size” field is also the maximum allowed length of the scheduled TXOP (in multiples of 4 microseconds), but additional rules may apply. In this exemplary embodiment, for a scheduled STA-STA transmission, the TXOP contains only one PPDU. The receiving STA uses the maximum PPDU size indicated in the assignment element to determine the number of OFDM symbols in the PPDU (because the PPDU size field is replaced by a required field in SIGNAL1, it will be described in detail below with reference to Figure 51). If the STA-STA data stream uses OFDM symbols with a standard guard interval (GI), the TXPDU PPDU size of the receiving STA is set to the maximum PPDU size indicated in the assignment element. If the STA-STA data stream uses OFDM symbols with shortened GI, the receiving STA will scale the maximum PPDU size by a factor of 10/9. 96852.doc -108 * 200527846 Decimal place and rounding method to determine the PPDU size. The transmitting STA may transmit a PPDU shorter than the assigned maximum PPDU size. The PPDU size does not provide the length of the aggregated MAC frame to the receiver. The length of the encapsulated frame is included in the summary header of each MAC frame.

The transmitting STA and the receiving STA are included in the assignment element, allowing STAs that have not been scheduled to transmit or receive during the SCAP to save power. Recall the SCHBD count field described earlier. Each assignment scheduled by the SCHED message specifies the transmitting STA AID, the receiving STA AID, the start time of the scheduled TXOP, and the maximum permitted length of the scheduled TXOP. The SCHED count is incremented on every SCHED transmission, and the SCHED count is reset on every beacon signal transmission. STAs can indicate a power saving operation to the AP, so during the AP may assign its scheduled transmission or receive TXOP, a specific SCHED count will be provided to their STAs. Then, the STA can be woken up periodically to listen to only the SCHED messages with an appropriate SCHED count.

Figure 49 of the PPDU format shows an old 802.1 1 PPDU 4970, which includes a PLCP preamble 4975 (12 OFDM symbols), a PLCP header 4910, a variable-length PSDU 4945, a 6-bit tail 4950, and Variable length padding term 4955. Part 4960 of PPDU 4970 includes a SIGNAL field (1 OFDM symbol) transmitted using BPSK with a ratio of 1/2 and a variable-length data field 4985 transmitted using the modulation format and rate indicated in SIGNAL 4980. . The PLCP header 4910 includes a SIGNAL 4980 and a 16-bit service field 4940 (which is included in DATA 4985 and transmitted in its format 96852.doc -109- 200527846). SIGNAL field 4980 includes rate 4915 (4 bits), reserved block 4920 (1 bit), length 4925 (12 bits), parity check bit 4930, and trailing end 4935 (6 bits) . The extended SIGNAL field (described in more detail below) in this exemplary PLCP header is backward compatible with the SIGNAL field 4980 in the old 802.1 1. The unused RATE field 49 15 in the old SIGNAL block 4980 is set to define the new PPDU type (explained in detail below). Describes several PPDU types. In order to be backward compatible with the old STA, the rate field in the SIGNAL field in the PLCP header was changed to the rate / type field. Unused RATE values are specified as PPDU types. The PPDU type also indicates the presence and length of a SIGNAL field that is extended by a SIGNAL field. The new values for the rate / type fields are defined in Table 4. Their rate / type bit values are undefined in the legacy STA. Therefore, the old STA will abort decoding the PPDU after successfully decoding the SIGNAL1 field and finding an undefined value in the rate field. Alternatively, the reserved bit in the old SIGNAL field can be set to 'Γ' to indicate a MIMO transmission to be transmitted to the new-type STA. The receiver STA ignores the reserved bits and continues to try to decode the SIGNAL block and the rest of the transmission. The receiver can determine the length of the SIGNAL2 field based on the PPDU type. FRACH PPDUs only appear in a specified part of the SCAP and can only be decoded by the AP. 96852.doc -110- 200527846 Table 4: ΜΙΜΟ PPDU type rate / type (4 bits) ΜΙΜΟ PPDU SIGNAL2 Field length (in OFDM symbols) 0000 ΜΙΜΟ BSS IBSS or ΜΜΟ AP transmission (except SCHED PPDU) 1 0010 ΜΙΜΟ BSS SCHED PPDU 1 0100 ΜΙΜΟ BSS FRACH PPDU 2 Figure 50 illustrates an exemplary MIMO PPDU format for data transmission 5 000 ° PPDU 5000 is designated as PPDU type 0000. PPDU 5000 includes a PLCP leading item 5010 'SIGNAL 1 5020 (1 OFDM symbol), SIGNAL 2 5040 (1 OFDM symbol), trailing symbol 5060 (0, 2, 3, or 4 symbols) and a variable length data Field 5080. In this exemplary embodiment, the PLCP leading term 5010, if any, is 16 microseconds. SIGNAL 1 5020 and SIGNAL 2 5040 are transmitted using the PPDU to control the fragment rate and modulation format. The data 5080 includes a service 5082 (16 bits), a feedback 5084 (16 bits), a variable-length PSDU 5086, a trailing end 5088 (6 bits per data stream), and a variable-length padding item 5090. 5080 will be transmitted using the PPDU data fragment rate and modulation format. ΜΙΜΟ PLCP header 5020 of PPDU type 0000 includes SIGNAL (including SIGNAL1 5020 and SIGNAL2 5040), month service 5082, and feedback 5084 and other fields. The service field is from the old 802.1 1 without change, and is transmitted using the data fragment rate and format. The feedback field 5084 is transmitted using the data segment rate and format. Anti-96852.doc -Ill- 200527846 Feed fields include ES field (1 bit), Data Rate Vector Feedback (DRVF) field (13 bits), and power control block (2 Bit). The ES field indicates the best control method. In this exemplary embodiment, when the ES bit is set, Eigenvector Steering (ES) is selected; otherwise, Spatial Spreading (SS) ° Data Rate Vector Feedback (DRVF) field is provided to provide information about Feedback from up to four supported spatial modes to peer stations. Clear rate feedback allows stations to quickly and accurately maximize their transmission rates, significantly improving system efficiency. Low latency feedback is what we expect. However, feedback opportunities do not have to be synchronized. Transmission opportunities can be obtained in any way, for example, competitive (ie, EDCA), polling (ie, HCF), or scheduled (ie, ACF). Therefore, a variable amount of time passes between transmission opportunities and rate feedback. Depending on the rate feedback period, the transmitter can apply a backoff to determine the transmission rate. The PPDU data segment rate adjustment for transmission from STA A to STA B relies on the feedback provided by STA B to STA A (as described above, for example, see Figure 24). For ES or SS mode of operation, each time STA B receives the MIMO training symbol from STA A, it evaluates the achievable data rate for each spatial data stream. In any subsequent transmissions from STA B to STA A, STA B is including this evaluation in the DRVF field of feedback 5084. The DRVF field is transmitted at a data fragment rate of 5080. When transmitting to STA B, STA A will determine the transmission rate to use based on the 96852.doc -112- 200527846 DRVF it received from STA B and an optional bounce that takes into account the delay. The SIGNAL field (explained in detail below) includes the 13-bit DRV field 5046, which is used to allow the receiver STA B to decode the frame transmitted by STA A. The DRV 5046 is transmitted at the control fragment rate. The DRVF field is encoded to include one STR block (4 bits), one R2 field (3 bits), one R3 field (3 bits), and one R4 field (3 bits) . The STR field indicates the rate of stream 1. This field is coded according to the STR values shown in Table 5. R2 indicates the difference between the STR value of data stream 1 and the STR value of data stream 2. The R2 value of "11Γ 'indicates that data stream 2 is closed. R3 indicates the difference between the STR value of data stream 2 and the STR value of data stream 3. The R3 value of f' 111" indicates that data stream 3 is Disabled. If R2 = "ll", R3 is set to Mil ". R4 indicates the difference between the STR value of data stream 3 and the STR value of data stream 4. R4 of the" 111 "value indicates that data stream 4 is Disabled. If R3 = 'f 111π, R4 is set to' '11 Γ'. When ES = 0 (that is, spatial expansion), the DRVF encoding method is replaced as follows: the number of data streams (2 bits), and the rate of each data stream (4 bits). The per-flow rate field is coded according to the aforementioned STR value. The remaining 7 bits are reserved. 96852.doc 113- 200527846 Table 5: STR encoding method

In addition to this, STAB also provides power control feedback to the transmitting party STA A. This field is included in the power control block and is transmitted using the data fragment rate. This block is 2 bits, and indicates whether to increase or decrease the power, or | _ 杜 #, 玄 >, Ren and 疋 to maintain the power level unchanged. The transfer wheel power level of the result is named the data segment transmission power level. Table 6 lists exemplary persuasive table approvals. Alternative specific embodiments can deploy various sizes of power batch total dry-range technology, and use the alternative power adjustment 96852.doc -114- 200527846 Table 6 · Power Control Block Value Power Control Block Meaning 00 No change 01 Increasing power in 1 dB increments 10 Decreasing power in 1 dB increments 11 Retained throughout the PPDU period, the transmission power level remains constant. When the transmission power level of the lean material segment is different from the open loop sta transmission power (that is, the power level required for decoding transmission at the AP, as described above), the maximum power of these two power levels will be used Level to transmit PPDU. That is, the PPDU transmission power level is the maximum of the transmission power level of the open-loop STA (aggravated) and the transmission power level of the data segment (dBm). -In this non-specific embodiment, the power control block will be set to "〇〇" in the first flood frame 'in any frame exchange sequence. In subsequent frames, this field indicates an increase or decrease in power in i dB increments. The receiving STA will use this feedback information in all subsequent frame transmissions to that STA. SIGNAL1 5020 includes rate / type block 5022 (4 bits), 1-bit reserved bit 5024, PPDU size / requirement 5026 (12 bits), parity check bit 5028, and 6 bits The trailing end is 503. The SIGNAU field 5020 is transmitted using the control fragment rate and mode (6 Mbit / s in this exemplary embodiment). The rate / type block 5022 is set to ⑼⑼. Reserved bit 5024 can be set to zero. 96852.doc -115- 200527846 The PPDU size / requirement field 5026 has two functions, and its function depends on the transmission mode. In contention-based STA transmission and all AP transmissions, this field indicates the PPDU size. In this first mode, bit 1 indicates that the ppDU uses extended OFDM symbols, bit 2 indicates that the PPDU uses OFDM symbols with a shortened GI, and bits 3-12 indicate the number of OFDM symbols. In scheduled non-AP STA transmissions, the PPDU size / request field 5026 indicates the request. In this second mode, bits 1-2 indicate the SCHED rate. The SCHED rate indicates the highest coded SCHED (0, 1, 2 or 3) field available for transmission to a STA. During the transmission of training symbols from an AP, each non-AP STA evaluates the rate at which it can strongly receive SCHED frame transmissions from that AP. In subsequent scheduled transmissions from the STA, the maximum allowable rate is included in the SCHLD rate field. This field is decoded by the AP. The AP uses this information to schedule subsequent TXOPs of the STA and decides to issue a CTRLJ (0, 1, 2 or 3) configured to the STA. In this second mode, bits 3-4 indicate the QoS field, and the required score (in units of one third) of this QoS field TC 0 or 1 (ie, 0%, 33%, 67 %, 100%). Bits 5-12 indicate the required length of the TXOP (in multiples of 16 microns in this exemplary embodiment). The SIGNAL1 field 5020 is checked using the 1-bit parity check bit 5028 and terminated with a 6-bit trailing end 5 0 3 0 to cooperate with the convolutional encoder. The presence and length of the SIGNAL2 bit 5040 is indicated by the rate / type field 5022 in the SIGNAL1 field 5020. SIGNAL2 field 5040 is 96852.doc -116- 200527846 and transmitted using the control fragment rate and format. SIGNAL2 5040 includes a reserved bit 5042, a training type 5044 (3 bits), a data rate vector (DRV) 5046 (13 bits), a parity check bit 5048, and a trailing end 5050 (6 bits). The 3-bit training type field indicates the length and format of the MIMO training symbol. Bits 1-2 indicate MIMO training symbols 5060 (0, 2, 3, or 4 OFDM symbols). Bit 3 is the training type Field: 0 indicates SS; 1 indicates ES. The DRV 5046 provides individual rates for up to four spatial modes. DRV 5046 is coded in the same way as DRVF (included in feedback 5084, as described above). The SIGNAL2 field 5040 is checked by using the 1-bit parity check bit 5048 and terminated by a 6-bit trailing end 5050 to cooperate with the convolutional encoder. Figure 51 shows the SCHED PPDU 5100 (rate / type = 0010). SCHED PPDU 5100 includes a PLCP leading item 5110, SIGNAL 1 5120 (1 OFDM symbol), SIGNAL 2 5 140 (1 OFDM symbol), tail symbol 5160 (0, 2, 3, or 4 symbols) and a variable Length SCHED frame 5180. In this exemplary embodiment, the PLCP leading term 5010 (if any) is 16 microseconds. SIGNAL 1 5020 and SIGNAL 2 5040 are transmitted using the PPDU to control the fragment rate and modulation format. The SCHED frame 5180 can include various rates, as described above with respect to the ACF. The SIGNALl field 5120 includes rate / type 5122 (4 bits), a reserved bit 5124, CTRL0 size 5126 (6 bits), CTRL1 size 5 128 (6 bits), parity check bit 5130, and Trailing end 5132 (6 bits). The rate / type 5 122 is set to 0010. Reserved bit 5124 can be set to zero. The CTRL0 size of 5 126 indicates the segment length of a SCHED PPDU transmitted at the lowest rate (96852.doc -117- 200527846 6 Mbps in this example). This snippet includes the PLCP header's monthly service stall, the MAC header, and the CTRL0 segment 5126. In this example, this value is encoded in multiples of 4 microseconds. The CTRL 1 size 5128 indicates the segment length of the SCHED PPDU transmitted at the next higher rate (12 Mbps in this example). In this example, this value is encoded in multiples of 4 microseconds. The '0' value of CTRL1 indicates that there is no corresponding CTRL1 segment in the SCHED PPDU. The SIGNAL1 field 5120 is checked using the 1-bit parity check bit 5130 and terminates with a 6-bit tail 5132 to cooperate with the convolutional encoder. SIGNAL2 5140 includes a reserved bit 5142, training type 5144 (3 bits), CTRL2 size 5146 (5 bits), CTRL3 size 5148 (5 bits), FCS 5 150 (4 bits) and tail End 5 152 (6 bits). Reserved bits 5 142 can be set to zero. Training type 5144 is designated as PPDU type 0000 (training type 5044). The CTRL2 size 5146 indicates the segment length of a SCHED PPDU transmitted at the next highest rate (18 Mbps in this example). In this example, this value is encoded in multiples of 4 microseconds. The '0' value CTRL2 size indicates that there is no corresponding CTRL2 segment in the SCHED PPDU. CTRL3 size 5 148 indicates the segment length of the SCHED PPDU transmitted at the highest rate (24 Mbps in this example). In this example, this value is encoded in multiples of 4 microseconds. The '0f value CTRL3 size indicates that there is no corresponding CTRL3 segment in the SCHED PPDU. The entire SIGNAL1 and SIGNAL2 fields will be used to calculate FCS 5150. The SIGNAL2 field 5140 is terminated by a 6-bit trailing end 5152 to match the volume encoder 96852.doc -118- 200527846. Figure 52 shows the FRACH PPDU 5200 (rate / type = 0010). FRACH PPDU 5200 includes a PLCP preamble 5210, SIGNAL 1 5220 (1 OFDM symbol), and SIGNAL 2 5240 (2 OFDM symbols). In this exemplary embodiment, the PLCP leading term 52 10 (if any) is 16 microseconds. SIGNAL 1 5220 and SIGNAL 2 5240 are transmitted using the PPDU to control the fragment rate and modulation format. The FRACH PPDU 5200 is transmitted by the STA during the FRACH period of the MIMO scheduled access period. The FRACH period was established by AP and is therefore known to AP. SIGNAL1 5220 includes rate / type 5222 (4 bits), a reserved field 5224, requirement 5226 (12 bits), parity check bit 5228, and end 5 230 (6 bits). The rate / type 5222 is set to 0100. Reserved bit 5124 can be set to zero. The requirement field 5226 is specified as PPDU type 0000 (5000), as described above. The SIGNAL1 field 5220 is checked using the 1-bit parity check bit 5228 and terminates with a 6-bit tail 5230 to match the convolutional encoder. SIGNAL2 5240 includes a reserved bit 5242, source AID 5244 (16 bits), destination AID 5246 (16 bits), FCS 5248 (4 bits) and trailing end 5250 (6 bits). The reserved bit 5242 can be set to zero. The source AID field 5244 identifies the STA transmitting on FRACH. The destination AID field 5246 identifies the destination STA required by the TXOP. In this exemplary embodiment, if the destination is an AP, the destination AID field 5246 is set to 2048. The entire SIGNAL1 and SIGNAL2 fields will be used to calculate one-bit FCS 5248. A 6-bit tail is added before convolutional coding. 96852.doc -119- 200527846 5250 〇 In this exemplary embodiment, the STA can use the slot Aloha (slotted Aloha) to access the channel Transmission request message. If successfully received by the AP, the AP will provide a scheduled TXOP to the requesting STA in a subsequent scheduled access time. The number of FRACH slots in the currently scheduled access period is indicated in the SCHED message (N_FRACH).

STA can also maintain a variable B-FRACH. After one transmission on FRACH, if the STA receives a TXOP assignment from the AP, it will reset B_FRACH. If the STA does not receive a TX0P assignment within the pre-determined number of RACH RESPONSE frames from the AP, the beq will force B_FRACH to 1 until the maximum value of 7. The parameter FRACH RESPONSE is included in an ACF element of the beacon signal. During any FRACH, the STA has (NJRACH) -1 * 2_B-FRACH probability to obtain the FRACH time slot. If the AP is not scheduled for any FRACH period, the MIM STA may use EDCA competition during protected competition periods during SCAP. Those skilled in the art will understand that information and signals may be represented using any of a variety of different terms or techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips are useful for representing voltage, current, electromagnetic waves, magnetic fields or particles, light fields or particles, or any combination thereof. Those skilled in the art should understand that the various illustrated logical blocks, modules, circuits, and algorithm steps described in conjunction with the specific embodiments published herein can be implemented as electronic hardware, computer software, or a combination thereof. In order to clearly explain the interchangeability of hardware and software, the foregoing has explained a wide range of components, blocks, modules, circuits and steps in various diagrams in terms of functions 96852.doc -120- 200527846. Depending on the specific application and design constraints affecting the entire system, the functionality is implemented as hardware or software. Those skilled in the art can use different methods to implement the described functions, but such implementation decisions cannot be regarded as departing from the scope of the present invention. Can use general-purpose processor, digital signal processor (Dsp), special integrated circuit (ASIC), field programmable gate (FpGA) or other private programmable logic device (PLD), discrete gate Or transistor logic, discrete hardware components, or any combination thereof to perform the functions described herein, to implement or execute the illustrated logical block logic modules and circuits in conjunction with the specific embodiments published herein. — The general-purpose processor may be a microprocessor, which is in a generation of cubes, and the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may be implemented as a group σ of a computer device, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors connected to a DSP core, or any other such configuration. The method or algorithm steps described in the disclosed specific embodiments can be directly embodied by hardware, a software module executed by a processor, or a combination of software and hardware. The software module can reside in RAM memory, flash memory, ROM memory, EPR⑽ memory, EEPROM memory, scratchpad, update disk, removable disk, CD_RC) M, or this technology In any other form of storage medium that is well known ... a kind of demonstration, _ storage medium fairy processing ^ 'so that the processor can read information from the storage medium and write data: to the storage medium. In the #generation program order, storage media can be integrated into the processing kit. The processor and the storage medium may reside in Asic. The dovec can be stored in 96852.doc -121- 200527846 in the user terminal. In the alternative +, the processor and storage media can be stored as discrete components in the user terminal. The headings listed in this article are for reference and to help find the paragraphs. These headings are not intended to limit the scope of the concepts described in this article. These concepts can be applied throughout the specification. The foregoing descriptions of the specific embodiments disclosed are provided so that those skilled in the art may use or utilize the present invention. Those skilled in the art should understand various modifications of these specific examples, and the general principles defined herein can be applied to other specific embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not limited to the specific embodiments presented herein, but conforms to the broadest scope consistent with the principles and novel functions described herein. [Brief description of the drawings] FIG. 1 illustrates an exemplary embodiment of a system including a high-speed WLAN; FIG. 2 illustrates an exemplary embodiment of a wireless communication device, which can be configured as an access point or User terminal; Figure 3 shows the 802 · 11 interframe spacing parameters; Figure 4 shows an exemplary physical layer (ρΗγ) transmission segment for explaining the use of DIFS plus return in accordance with DCF (Backoff) to perform access; FIG. 5 shows exemplary physical layer (PHY) transmission fragments for explaining the priority order over a DIFS access, using SIFS before an ACK; FIG. 6 shows splitting large packets into Smaller fragment with associated SIFS; Figure 7 shows an exemplary physical layer (PHY) transmission fragment to illustrate a TXOP with frame recognition per 96852.doc -122- 200527846; Figure 8 shows an area containing Block approved TXOP; Figure 9 shows an exemplary physical layer (PHY) transmission segment to illustrate a polled TXOP using HCCA; Figure 10 shows an exemplary specific TXOP including multiple continuous transmissions without any gaps Examples FIG. 11 shows an exemplary embodiment of a TXOP, which is used to explain the reduction of the necessary pilot preamble transmission amount. FIG. 12 shows an exemplary implementation of a method for incorporating various aspects. Examples include merging leading items, removing gaps such as SIFS, and inserting GIFs where appropriate; Figure 13 shows an exemplary physical layer (PHY) transmission segment for explaining merge polling and the corresponding TXOP; Figure 14 shows An exemplary embodiment of a method for merge polling; FIG. 15 illustrates an exemplary MAC frame; FIG. 16 illustrates an exemplary MAC PDU; FIG. 17 illustrates an exemplary peer-to-peer communication; and FIG. 18 illustrates a previous Technical entity layer bursts; Figure 19 illustrates an exemplary entity layer burst that can be deployed for peer-to-peer communication; Figure 20 illustrates a MAC frame including an optional ad hoc segment Exemplary specific embodiments; FIG. 21 illustrates an exemplary entity layer burst; 96852.doc -123- 200527846 FIG. 22 illustrates an exemplary method using FIG. 23 and a method using FIG. For peer-to-peer data transmission Exemplary method for peer-to-peer communication; Figure 25 for providing rate feedback used in peer-to-peer connection shows between two stations and lines; management peer-to-peer connection between access points Figure 26㈣ -Competitive (or proprietary (adhQe)) peer-to-peer connection, Figure 27 shows an exemplary MAC frame for explaining management peer-to-peer communication between stations; Figure 28 _Ratem supports old stations and new types of stations; Figure 29 shows a combination of old and new types of media access control; Figure 30 shows an exemplary method for winning transmission opportunities; Figure 31 shows multiple An exemplary method in which a BSS shares a single fa; FIG. 32 illustrates an overlay using a single 卩; 633; FIG. 33 illustrates an exemplary method for performing high-speed peer-to-peer communication and interoperating with an old BSS at the same time; FIG. 34 illustrates peer-to-peer communication using MIMO technology on a legacy BSS with competitive access; FIG. 35 illustrates encapsulation of one or more MAC frames (or fragments) within a summary frame; FIG. 36 illustrates 〆Old MAC frame; Figure 37 shows / exemplified decompression frame; Figure 38 8% shows / exemplary compression 96852.doc -124- 200527846 Figure 39 shows another exemplary compression frame; Figure 40 shows an exemplary Aggregation Header; Figure 41 shows the scheduled access period used in SCF An exemplary embodiment of a Scheduled Access Period Frame (SCAP); Figure 42 shows the way SCAP is used in conjunction with HCCA and EDCA; Figure 43 shows a beacon containing several SCAPs interspersed with contention-based access periods Signal (Beacon) interval;

FIG. 44 illustrates a low-latency operation with a large number of MIMO STAs; FIG. 45 illustrates an exemplary SCHED message; FIG. 46 illustrates an exemplary Power Management field; FIG. 47 illustrates an exemplary MAP field; 48 illustrates an exemplary SCHED control frame for TXOP assignment; FIG. 49 illustrates an old 802.1 1 PPDU; FIG. 50 illustrates an exemplary MIMO PPDU format for data transmission;

FIG. 51 illustrates an exemplary SCHED PPDU; FIG. 52 illustrates an exemplary FRACH PPDU; and FIG. 53 illustrates an alternative embodiment having a method for interoperability with legacy systems. [Description of main component symbols] 100 system 102 network 104 access point (AP) 106A-N user terminal (UT) 96852.doc -125- 200527846 110, 270 connection 120 wireless local area network (WLAN) 210 Transceiver 220 MAC processor 240 LAN transceiver (Figure 2) 250 AN antenna 255 memory 260 stream 280 feedback 400, 500, 600, 700, 800, 900, 1310 Physical layer (PHY) transmission fragments 410, 510, 610, 710, 810 Existing transmissions 420, 530 New transmissions 520 ACK (recognized) 620, 720 DCF interframe space (DIFS) 630, 730 Backoff 640A-640N, fragments 650A-650N, delayed SIFS 660A-660N, 760A-760N ACK frame 670A-670N-1, 750A-750N, SIFS 830A-830N, 930, 1340 740A-740N, 820A-820N, 1020 frame 770, 1120 leading entry 780 header and packet 790, 1010, 1110 TX0P (transmission opportunity) 96852.doc-126- 200527846 810 Block TX TX, 840, 1030, 1140 Block ACK requirement 920 Polling 940 Polling TXOP 1130A-1130N Continuous transmission 1310 Merged polling 1320 Forward link TXOP 1330A-1330N reverse link TXOP 1500 TDD MAC frame Every 1510 Broadcast Channel (BCH) (Transmission Channel Segment) 1520 Control Channel (CCH) (Transmission Channel Segment) 1530 Forward Traffic Channel (F-TCH) (Transmission Channel Segment) 1540 Reverse Traffic Channel (F-TCH) (Transmission Channel fragment) 1550 random access channel (RCH) (transmission channel fragment) 1560 fragment 1610 data packet 1620A-N fragment 1630 regulation sub-layer PDU 1634, 1644, 1654 packet payload (payload) 96852.doc -127- 200527846 1640 Λ, 1642 * 1646 1650 1652 1660 1662 1664 1666 1666Α 1800, 1900, 2100 1810 1820 1830, 1930 1940 1910 1920 2000, 2700 2010 ★ 2110 2120 2130 510 Logical link sub-layer PDU (LL PDU)

LL header CRC MUX sublayer PDU (MPDU) MUX header

MAC PDU MUX indicator Local MPDU New PDU

MPDU entity layer burst (PHY burst) Leader entity layer convergence protocol (PLCP) header data symbol peer-to-peer transmission (P2P) ΜΙΜΟ preamble ΜΙΜΟ transmission rate feedback TDD MAC frame interval optional random segment (A-TCH) Non-manipulated MIMO Leading Peer Common Control Channel (PCCH) Data Symbol Broadcast Channel (BCH)

96852.doc -128- 200527846 520 530 ^ 540 • 2410 2420 2430 2710 2720, 2730 2730 2902 2904 2906

2908A-N 2910 2910 2930

2932A-N 2950 • 3210

-3205, 3205A, 3205B, 3210 3215 Control Channel (CCH) Forward Traffic Channel (F-TCH) Reverse Traffic Channel (F-TCH) Unsteered pilot Channel transmission rate feedback configuration burst configuration fragment Beacon No Contention Period (CFP) No Contention Period (CP) No Contention Polling (CF Polling) No Contention Period End (UPEND) Old MAC Agreement New Type Agreement MAC Frame Combination MAC Protocol (Combined Beacon Time Interval) Legacy System Beacon No Competition Period Competition Period

96852.doc 129 · 200527846 3220A-N Polling with or without contention 3225 Non-competition period 3230 PIFS 3245 Legacy signal 3250 New category access period 3260 TDD MAC frame interval 3405 ΜΜΟ Leader 3410 Requirement 3415 SIFS 3420 Controlled Leader 3425 Approval and Transmission Rate Feedback 3430 Controlled Leader 3435 Data 3440 Controlled Leader 3445 Approval and Transmission Rate Feedback 3450 Controlled Leader 3455 Data 3510 MAC Frame (or fragment) 3520 Aggregated MAC Frame 3530 PSDU 3600 Legacy MAC Frame 3610 Frame Control field 3615 Duration / ID field 3620 Address 1 (TA)

96852.doc -130- 200527846 3625 Address 2 (RA) 3630 Address 3 (SA) 3640 Address 4 (DA) 3635 Sequence Control Field 3645 QoS Control Field 3650 Frame Body 3655 Frame Check Symbol (FCS) 3660 MAC header 3700, 3800, 3900 extended MAC header 3705, 3805, 3905 MAC frame encapsulated 3710 aggregate header 4100 SC AP (scheduled access period frame) 4010 aggregate header type block 4110 CTS- to-Self 4020 Reserved 4030 Length field 4120 SCHED message 4130 Scheduled access period 4140 Scheduled transmission 4142 AP to STA transmission 4144 STA to AP transmission 4146 STA to STA transfer wheel (equivalent TX0P) 4150 FRACH (fast random Access frequency

96852.doc -131- 200527846 channels) period 4160 4515-4530 4160 4210A-C 4220A-F 4230A-F 4510 4515-4530 4535 4540 OFDM EDCA CTRLJ element EDCA (Enhanced Distributed Channel Access) operation beacon signal (Beacon ) Contention Control (BDCA) CAP (Controlled Access Phase) MAC Header Fragment Frame Control Duration

4545 BSSID 4550 Power Management 4550 4610 4620 4630 4640 4710 4720 4730 4820 4840

MAP SCHED count reserved field transmit power receive power FRACH count FRACH offset EDCA offset CTRL0 assigned element CTRL1 assigned element 96852.doc -132- 200527846 4860 4880 4830, 4850, 4870, 4890 4910 4915 4920 4925 4930 4935 4945 4950 4955 4955 4970 4955 4960 4970 4975 4980 4985 5000 5010 5020 5022 5024

CTRL2 assigned element CTRL3 assigned element FCS PLCP header Transmission rate Reserved field Length Parity check bit End

PSDU tail padding Legacy 802.11 PPDU padding

A part of PPDU 4970 is the old 802.11 PPDU PLCP leading item SIGNAL data field (DATA) ΜΙΜΟ PPDU format PLCP leading item SIGNAL 1 Transmission rate / type field reserved field 96852.doc -133- 200527846 5026 5028 5030 * 5040 5042 5044 5046 5048 5050 5060 5080 5082 5084 5086 5088 5090 5310 5315 5320 5330 '5046 5100 5110 5120 PPDU size / requires parity check bit tail SIGNAL2 Reserved bit training type data rate vector (DRV) parity check bit tail end Symbol Data Field (DATA) Service Feedback

PSDU tail padding

Time slot time interval ΜΙΜΟ Leading time interval Time slot gap Modified MAC frame DRV SCHED PPDU PLCP leading item SIGNAL1

96852.doc -134- 200527846 5122 rate / type 5124 reserved bit 5126 CTRL0 size 5128 CTRL1 size 5130 parity check bit 5132 tail 5140 SIGNAL2 5142 reserved bit 5144 training type 5146 CTRL2 size 5148 CTRL3 size 5150 FCS 5152 end 5160 tail symbol 5180 SCHED frame 5200 FRACH PPDU 5210 PLCP leading 5220 SIGNAL 1 5222 rate / type 5224 reserved field 5226 requires 5228 parity check bit 5230 tail 5240 SIGNAL2 96852.doc -135- 200527846

5242 Reserved bits 5244 Source AID 5246 Destination AID 5248 FCS 96852.doc-136-

Claims (1)

200527846 Scope of patent application 1. A device, including: a transmitter for transmitting a signal in accordance with a flute ^ ^, ^, ?? transmission format, borrow? Retaining-shared media during the duration, and used to hold the transmission in the retention mode: transmission mode; and receiving benefit 'is used to receive in the manner during the duration of the reservation. & 2. A device comprising: a hair shooter for transmitting in accordance with at least a part of the -th- communication format, and for transmitting in accordance with the "zhao- ^", "one-pass" format; a receiver For receiving in accordance with the second communication format; and a shared media retaining component 'for retaining the duration of the reservation on a daily basis " the second transmission format in a chanting technology disease # ... ^ ^ 通 ^ Shared media 3. A wireless communication system comprising: a transmission component for transmitting a signal in accordance with a first transmission format, and mistakenly reserved for a continuous period of shared media; and Communication is performed in accordance with this formula for the duration of the reservation. 4. A method for interoperating on a common medium between a device or devices communicating in accordance with a first transmission format and a device or devices communicating in accordance with a second transmission format. The method includes: , Transmitting a signal in accordance with the -first-transmission format, so as to retain the shared media between the parties; and "96852.doc 200527846 communicating in accordance with the second transmission format during the duration of the warranty. 5. The method as claimed in item 4 further comprises competing for access according to the first transmission format before transmitting the signal for reservation. 6. The method of claim 4, further comprising: requesting access to the shared media; and receiving a configuration in response to the request. 7. Shi Ming's method of finding item 4 'wherein the signal is a transmission opportunity (TXOP) according to a protocol. 8. The method of seeking item 4 as stated, wherein the signal is set up for a period without competition. The shared media signal includes transmitting a request for transmission (RTS) message, and the RTS information indicates a transmission duration. If the method of item 4 is explicitly requested, wherein a transmission is used to reserve the name for a duration, the signal of the media includes the transmission of a clear transmission (CTS) message, the CTS message indicating a transmission duration. 802.11 mode. (TDD) frame interval, which includes: a leading pilot signal; a combined poll; To remote station frame; station to access point frame; station to remote station frame 96852.doc 200527846 frame; and zero or more random access fragments according to the combined poll. 13. · A device comprising: a configuration component configured to configure a first duration of a common media communication according to a first communication format of a plurality of communication formats, and a configuration component configured to configure For a second duration of the common media communication in accordance with a second communication format of the plurality of communication formats. U. The apparatus of claim 13, further comprising means for space processing. 15. A computer-readable medium operable to perform the following steps: configured for a first duration of a common media communication in accordance with a first communication format of a plurality of communication formats; and During a second duration of the common media communication according to a second communication format of the plurality of communication formats. 16. If the media of item 15 is requested, it may further operate to perform the following steps: transmit a time-division duplex (TDD) frame interval including a combined poll; Transmitting one or more frames; and knowing, combining polling to receive one or more frames. A method for communicating on a common medium configured for a first duration of the common media communication in accordance with a first communication format of the plurality of communication formats; and One of the second communication formats comes during a second duration of the shared media communication. The method of female month-long item 17 wherein at least one of the plurality of communication formats is 96852.doc -3- 200527846 and the letter format includes space processing. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. The method of claim 18, wherein the communication format including the spatial processing of the plurality of communication formats is a multiple input multiple output (MIM〇) Communication format. The method of claim 19, wherein the MIMO communication format is a multiple-input single-output (MISO) communication format. The method of claim 17, wherein one of the plurality of communication modes includes a time division duplex (TDD) frame interval, which includes: a preamble signal; a combined polling; and knowledge, the Merge one or more frames. The method of claim 21, wherein one or more of the frames include an access point to a remote station communication. For example, in the method of% 21, one or more frames include remote station-to-access point communication. If the method of item 21 is sought, one or more of the frames include remote station to remote station communication. For example, if the method is called term 21, one or more frames include random access to the shared media. The method of claim 17, wherein one of the plurality of communication formats is substantially the same as an 802.1 1 EDCA format. The method of claim 17, wherein one of the plurality of communication formats is substantially the same as an 802.1 1 CAP format. For example, the method of claim 17, wherein one of the plurality of communication modes is commonly used as 96852.doc 200527846. The format is only qualitatively the same as an SC AP format. 29. The method of claim 17, further comprising configuring for a continuous or evening third duration of the shared media communication in accordance with a first communication format of the plurality of communication formats, and for performing a plurality of communication formats One of the second communication formats is to intersperse the continuous one or more @M four continuous periods, the third continuous period, and the second continuous period of the shared media communication. 30. The method of expressing item 29, wherein the interpolation is selected so as to provide a maximum time interval between successive second durations. 31. The method of claim 17, wherein the first duration includes one or more SCAP time intervals. 3 2. The method of expressing item 3 丨, wherein the second duration includes one or more 802_11 EDCA time intervals. 33. The method of claim 17, further comprising establishing a non-competition period during the first duration period. 3 4 · If the method of claim 17 is provided, further comprising establishing a competition period during the second duration period. 35. A device comprising: a brother contention component for competing access to a shared media in accordance with a first communication protocol; and a communication component for sharing a second communication during the contention access. Agreement to communicate on the shared media. 36. A method for communicating on a common medium, including: transmitting a 彳 § beacon; 96852.doc -5- 200527846 in accordance with a first-recitation line + a second communication protocol Shared Media Center® is determined to compete for access to the shared media; and to communicate over the competitive access period. It further includes the establishment of a no-competition period; a method such as requesting item 36, and the configuration of the round according to the first communication protocol during the period of " Hai Wuyan brothers " 38. Such as request item 36 The method further includes: competing for a second access to the shared media according to the first communication protocol; and communicating on the shared media according to the first communication protocol during the second competitive access. 39. The method of claim 37, wherein: a first access point establishes the non-contention period; and a second access point competes for access in accordance with the first communication protocol, and during the competitive access in accordance with The second communication protocol is used to communicate with one or more remote stations. 40. A device capable of cooperating with an access point, the access point establishing a non-competition period and a competition period in accordance with a first communication protocol, the device comprising: a competition component for the non-competition period During the competitive access, a transmitter for transmitting in accordance with a second communication protocol; and 96852.doc-6 · 200527846 a receiver for transmitting in the competition Transmission during the access is performed in accordance with the second communication protocol. 41. A computer-readable medium operable to perform the following steps: competition for access to the shared media in accordance with a first communication protocol; and access to the shared media in accordance with a second communication protocol during the competitive access On communication. 42. A wireless communication system comprising: a device for: competing access to the shared media in accordance with a first communication protocol; and transmitting a signal in accordance with the first communication protocol to retain the sharing for a sustained period Media; a first remote station for transmitting a preamble signal in accordance with a second communication protocol; and a second remote station for: measuring the preamble signal and determining feedback based thereon; and transmitting the feedback to The first remote station. 43. The wireless communication system of claim 42, wherein the first remote station further transmits data to the second remote station according to the feedback and according to the second communication protocol. 44. A method for communicating on a common medium, comprising: competing access to the common medium in accordance with a first communications protocol; transmitting a signal in accordance with the first communications protocol to retain the common medium for a sustained period ; According to a second communication protocol, transfer a preamble 96852.doc 200527846 signal from a first remote station to a second remote station; measure the preamble signal at the second remote station and determine a accordingly Feedback; ', feedback from the second remote station to the first remote station. And 0, according to the feedback, according to the second communication protocol, data is transmitted from the first end-to-end station to the Second remote station. 45. A wireless communication device capable of operating in conjunction with a shared media for receiving and transmitting, comprising: ",,,,,, and a first access point for communicating in accordance with a first communication format; and a first Two access points for communicating in accordance with a second communication format. The second access point is operable to transmit a signal in accordance with the first communication format, so as to retain the shared media during the holding period. According to Zhao Gao: letter format communication.… — 通 96852.doc 8-