1.https://blog.csdn.net/strugglelg/article/details/38927633
<https://blog.csdn.net/strugglelg/article/details/38927633>（WiFi基本知识）

2.https://blog.csdn.net/strugglelg/article/details/38893287
<https://blog.csdn.net/strugglelg/article/details/38893287>（2.4G wifi 的频道/信道
20M 40M的概念，区别）

1.WiFi分析仪

2.4G+5G的路由器。

2.ScanResult

ScanResult是代表扫描结果的，当时其声明的成员变量并没有带有channel，那WiFi分析仪是如何获取信道的呢？

3.获取信道方法

3.1 频谱划分

1）IEEE 802.11b/g标准工作在2.4G频段，频率范围为2.400—2.4835GHz，共83.5M带宽

2）划分为14个子信道

3）每个子信道宽度为22MHz
4）相邻信道的中心频点间隔5MHz
5）相邻的多个信道存在频率重叠(如1信道与2、3、4、5信道有频率重叠)
6）整个频段内只有3个（1、6、11）互不干扰信道

3.2 2.4GHz中国信道划分

3.3 计算信道

ap的频率为2462MHz，而2462MHz是信道11的中心频率，WiFi分析仪则认为该AP是处于信道11上，那后面11+7是什么意思呢？

40MHZ 实际上是用了两个频道， 20MHZ 实际上是用了1个频道 。

4. ScanResult PS

/** * AP Channel bandwidth is 20 MHZ */ public static final int
CHANNEL_WIDTH_20MHZ = 0; /** * AP Channel bandwidth is 40 MHZ */ public static
final int CHANNEL_WIDTH_40MHZ = 1; /** * AP Channel bandwidth is 80 MHZ */
public static final int CHANNEL_WIDTH_80MHZ = 2; /** * AP Channel bandwidth is
160 MHZ */ public static final int CHANNEL_WIDTH_160MHZ = 3; /** * AP Channel
bandwidth is 160 MHZ, but 80MHZ + 80MHZ */ public static final int
CHANNEL_WIDTH_80MHZ_PLUS_MHZ = 4; /** * AP Channel bandwidth; one of {@link
#CHANNEL_WIDTH_80MHZ_PLUS_MHZ}. */ public int channelWidth;

/** * Not used if the AP bandwidth is 20 MHz * If the AP use 40, 80 or 160
MHz, this is the center frequency (in MHz) * if the AP use 80 + 80 MHz, this is
the center frequency of the first segment (in MHz) */ public int centerFreq0;
/** * Only used if the AP bandwidth is 80 + 80 MHz * if the AP use 80 + 80 MHz,
this is the center frequency of the second segment (in MHz) */ public int
centerFreq1;
ssid
/** * The network name. */ public String SSID; /** * Ascii encoded SSID. This
will replace SSID when we deprecate it. @hide */ public WifiSsid wifiSsid; /**
* The address of the access point. */ public String BSSID; /** * The HESSID
from the beacon. * @hide */ public long hessid;

/** * The detected signal level in dBm, also known as the RSSI. * * <p>Use