在Android WifiManager中Rssi的含义是什么？

Question

我试图获得当前wifi连接的信号强度 getRssi()

private void checkWifi(){
    ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo Info = cm.getActiveNetworkInfo();
    if (Info == null || !Info.isConnectedOrConnecting()) {
        Log.i("WIFI CONNECTION", "No connection");
    } else {
        int netType = Info.getType();
        int netSubtype = Info.getSubtype();

        if (netType == ConnectivityManager.TYPE_WIFI) {
            wifiManager = (WifiManager)getApplicationContext().getSystemService(Context.WIFI_SERVICE);
            int linkSpeed = wifiManager.getConnectionInfo().getLinkSpeed();
            int rssi = wifiManager.getConnectionInfo().getRssi();
            Log.i("WIFI CONNECTION", "Wifi connection speed: "+linkSpeed + " rssi: "+rssi);


        //Need to get wifi strength
        } 
    }
}

事情是我得到像-35或-47等数字...我不明白他们的价值观..我已经看了android文档及其所有状态:

public int getRssi()

从以下版本开始:API Level 1返回当前802.11网络的接收信号强度指示符.

这不是规范化的,但应该是!

返回RSSI,范围是??? 至 ？？？

谁能解释如何"正常化"或理解这些结果？

Answer 1

我在WifiManager.java中找到了这个:

/** Anything worse than or equal to this will show 0 bars. */
private static final int MIN_RSSI = -100;

/** Anything better than or equal to this will show the max bars. */
private static final int MAX_RSSI = -55;

android上的相关rssi范围是-100和-55.

有一个静态方法WifiManager.calculateSignalLevel(rssi,numLevel)将为您计算信号级别:

int wifiLevel = WifiManager.calculateSignalLevel(rssi,5);

返回0到4之间的数字(即numLevel-1):您在工具栏中看到的条数.

Answer 2

根据IEEE 802.11文档:较小的负值表示较高的信号强度.

范围在-100到0 dBm之间,接近0是强度更高,反之亦然.