DFS设备
| 主设备 | 具有雷达探测能力的设备，可以 控制网络中的其他设备（例如， 接入点/SoftAP/P2P-GO 被视为 主设备）。 |
| 客户端设备 | 没有和主设备连接，无法工作在DFS频段上的设备 （例如，笔记本电脑/移动客户端——即 连接到 DFS 通道上的主设备。 请注意，支持 ad-hoc 模式的 Wi-Fi 卡 被视为主设备）。 |
DFS 相关名称介绍
| Channel availability check (CAC) | Mechanism by which an RLAN device checks a channel for the presence of radar signals. No transmissions are permissible for this device within the channel being checked during this process. If no radars are detected, the channel becomes an available channel. |
| Channel Availability Check Time (CAC Time) | The time a system shall monitor a channel for the presence of radar prior to initiating a communications link on that channel. |
| Off-channel CAC | An optional mechanism by which an RLAN monitors channels, different from the Operating Channel, for the presence of radar signals. (Only defined in ETSI DFS requirements). |
| In-service monitoring | The process by which an RLAN monitors the Operating Channel for the presence of radar signals. |
| Interference Detection Threshold | The minimum signal level, assuming a 0 dBi antenna, that can be detected by the system to trigger the move to another channel. |
| Channel Move Time | The time for the system to clear the channel and measured from the end of the radar burst to the end of the final transmission on the channel. |
| Channel shut-down | The process initiated by the RLAN device on the Operating Channel. This process shall start immediately after a radar signal has been detected on the Operating Channel. |
| Channel Closing Transmission Time | The total, or aggregate, transmission time from the system during the channel move time. |
| Non-occupancy period | The time during which the RLAN device shall not make any transmissions on a channel after a radar signal was detected on that channel. |
| Uniform Spreading | The mechanism to be used by the RLAN to provide, on aggregate, a uniform loading of the spectrum across all devices |
DFS工作原理
主设备选择一个通道并检查它是否是一个DFS通道。如果频道是 DFS 通道，主设备启动 CAC 周期以监视该通道的潜在雷达 最小 CAC 时间的干扰。在此期间不能进行任何传输。如果 检测到干扰，则系统必须选择另一个频道并重复该频道 对新频道的可用性检查。原始频道被添加到频道列表中雷达。
选择一个通道并通过通道可用性检查后，网络开始使用那个频道。
在使用通道时，网络主设备会持续监控潜在的 来自雷达源的干扰称为在役监测。如果检测到干扰， 网络主设备向所有其他网络内设备发出命令以停止 传输。该频道被添加到带有雷达和主设备的频道列表中 选择不在列表中的新频道。该序列再次以频道可用性开始 查看。
雷达列表上的频道可以在该频道的非占用期过去后被清除 渠道。 DFS 的监管要求可能因国家/地区而异，但基本原则是相同的。
DFS 响应要求值
| Non-occupancy Period | ≥ 30 minutes |
| Channel Availability Check Time | ≥ 60 s |
| Channel Move Time | ≤ 10 s |
| Channel Closing Transmission Time | ≤ 260 ms |