802.11 MAC Protocol
802.11 MAC 协议

The IEEE^® 802.11™ family of standards implements the medium access control (MAC) layer as a frame exchange protocol. By means of this protocol, the sender of a MAC frame can determine when the intended recipient successfully receives that frame. The sender transmits the MAC frame in the data field of a physical layer convergence procedure (PLCP) protocol data unit (PPDU). For more information on WLAN PPDU content, see WLAN PPDU Structure. For more information on the role of the MAC layer in WLAN message exchange, see What Is WLAN?
IEEE^® 802.11™标准系列实现了介质访问控制（MAC）层作为一种帧交换协议。通过该协议，MAC 帧的发送方可以确定预期接收方何时成功接收该帧。发送方将 MAC 帧传输到物理层收敛过程（PLCP）协议数据单元（PPDU）的数据字段中。有关 WLAN PPDU 内容的更多信息，请参见WLAN PPDU 结构。有关 MAC 层在 WLAN 消息交换中的作用的更多信息，请参见什么是 WLAN？

General MAC Frame Format 常规 MAC 帧格式

Section 9.2.1 of [1] specifies that the general MAC frame must consist of a MAC header, frame body, and a frame check sequence (FCS). MAC frames can be either protocol version 0 (PV0) or protocol version 1 (PV1). WLAN Toolbox™ supports only PV0 MAC frames. For information on PV1 MAC frames, see Section 9.8 of [1].
第 9.2.1 节的[1]指定一般 MAC 帧必须包含一个MAC 标头，帧正文和帧校验序列（FCS）。MAC 帧可以是协议版本 0（PV0）或协议版本 1（PV1）。 WLAN 工具箱™仅支持 PV0 MAC 帧。有关 PV1 MAC 帧的信息，请参见[1]的第 9.8 节。

This figure shows the fields comprising the MAC header of a PV0 MAC frame and their sizes in octets.
这个图显示了 PV0 MAC 帧的 MAC 头部字段及其以八位字节为单位的大小。

As indicated in Section 9.2.4 of [1], all MAC frames contain the first three header fields and the FCS. The frame type and subtype determine the additional fields that are contained in the frame.
如[1]中的第 9.2.4 节所示，所有 MAC 帧都包含前三个报头字段和 FCS。帧类型和子类型决定了帧中包含的附加字段。

The frame body, which immediately follows the header, has a variable size. Table 9-25 in [1] specifies the maximum size and duration of the frame body for non-HT, HT, VHT, and HE PPDU formats.
框架主体紧随标题之后，并且具有可变大小。在[1]中的表 9-25 指定了非-HT、HT、VHT 和 HE PPDU 格式的框架主体的最大大小和持续时间。

The FCS consists of a four-octet cyclic redundancy check (CRC), which the sender computes based on the frame header and body in accordance with Section 9.2.4.8 of [1].
FCS 由一个四字节的循环冗余校验（CRC）组成，发送方根据第 9.2.4.8 节中所述的帧头部和数据体计算。 [1]。

The combination of MAC header, frame body, and FCS defines a MAC protocol data unit (MPDU). This figure shows the structure of an MPDU and its placement within a PPDU.
MAC 标头、帧主体和 FCS 的组合定义了一个MAC 协议数据单元（MPDU）。该图显示了 MPDU 的结构及其在 PPDU 内的放置位置。

To increase throughput, IEEE 802.11 supports the formation of aggregate MPDUs (A-MPDUs) by concatenating multiple MPDUs. For more information on MPDU aggregation and A-MPDU structure, see section 9.7 of [2].
为了增加吞吐量，IEEE 802.11 支持通过串联多个 MPDU 来形成聚合 MPDU (A-MPDU)。有关 MPDU 聚合和 A-MPDU 结构的更多信息，请参阅[2]的第 9.7 节。

MAC Frame Types MAC 帧类型

IEEE 802.11 supports four types of MAC frame: Management, Control, Data, and Extension frames. Within each of these types, the standards define a variety of subtypes. Table 9-1 of [1] provides a list of the valid types and subtypes, and section 9.3 provides detailed information on frame formats by type and subtype.
IEEE 802.11 支持四种类型的 MAC 帧：管理、控制、数据和扩展帧。在每种类型中，标准定义了各种子类型。 [1]的表 9-1 提供了有效类型和子类型的列表，第 9.3 节提供了有关按类型和子类型划分的帧格式的详细信息。

This table shows the some of the supported frame types and subtypes for HE, VHT, HT, and non-HT transmission formats. For information on the format of any of these MAC frames, see the relevant sections of [1] and [2].
这个表格显示了 HE、VHT、HT 和非 HT 传输格式所支持的一些帧类型和子类型。有关任何这些 MAC 帧的格式信息，请参阅[1]和[2]的相关部分。

Each frame type serves a distinct purpose in an 802.11 network.
每个帧类型在 802.11 网络中都有不同的用途。

The Generate and Parse WLAN MAC Frames tutorial demonstrates the basic steps of MAC frame generation and decoding with WLAN Toolbox functions and configuration objects.
教程 生成和解析 WLAN MAC 帧 展示了使用 WLAN 工具箱函数和配置对象进行 MAC 帧生成和解码的基本步骤。

The 802.11 MAC Frame Generation example shows how to generate control, data, and management frames, and how to export frames to a packet capture (PCAP) file for analysis.
示例显示如何生成控制、数据和管理帧，以及如何将帧导出到数据包捕获（PCAP）文件进行分析。