AT+CSQ语法即GPRS模块信号格数与信号强度的关系 |
您所在的位置：网站首页 › gnsstoolkit3 信号强度 › AT+CSQ语法即GPRS模块信号格数与信号强度的关系 |
AT+CSQ语法即GPRS模块信号格数与信号强度的关系
|
AT+CSQ语法 命令解释：检查网络信号强度 命令格式：AT+CSQ 命令返回：+CSQ: **, ## 其中： **应在 0 到 31 之间（99表示无信号），数值越大表明信号质量越好；##为误码率，值在 0 到 99 之间。否则应检查天线或 SIM 卡是否正确安装
测试结果：AT+CSQ +CSQ: 31, 99 计算公式：信号强度 = -113dBm + (rssi * 2) 通过AT+CSQ指令获取GPRS模块信号强度 如下图所示： 信号格数与信号强度的关系 手机格数与手机接收基站的信号强度有关，目前行业中并没有明确的标准，格数与信号强度关联均为厂商而定，iPhone 4信号强度与格数如下图： 诺基亚手机和iPhone 4信号强度与格数对比如下： 信号格数 接收电平强度 诺基亚 iPhone4 5格： 大于-85dBm 大于-91dBm 4格: -85dBm至-90dBm -91dBm至-101dBm 3格: -90dBm至-95dBm -101dBm至-103dBm 2格: -95dBm至-100dBm -103dBm至-107dBm 1格: -100dBm至-105dBm -107dBm至-113dBm 脱网： 小于-105 dBm 小于-113dBm 注：上表数据均为5格信号显示方式，如N97等7格信号原则与上述不同。 在这里，我采用了android系统上关于GSM模块信号格数与信号强度的对应关系，如下代码所示： public int getGsmLevel() { int level; // ASU ranges from 0 to 31 - TS 27.007 Sec 8.5 // asu = 0 (-113dB or less) is very weak // signal, its better to show 0 bars to the user in such cases. // asu = 99 is a special case, where the signal strength is unknown. int asu = getGsmSignalStrength(); if (asu = 12) level = SIGNAL_STRENGTH_GREAT; else if (asu >= 8) level = SIGNAL_STRENGTH_GOOD; else if (asu >= 5) level = SIGNAL_STRENGTH_MODERATE; else level = SIGNAL_STRENGTH_POOR; if (DBG) log("getGsmLevel=" + level); return level; }上面的asu即AT+CSQ指令返回的RSSI值。 参考文章：http://blog.csdn.net/garybook/article/details/17006609
如果是CDMA模块，应该可以参考下面的代码： 参考文章：http://www.2cto.com/kf/201306/218756.html
在Android4.0的系统中，手机中显示信号强度格数的代码在 frameworks\base\telephony\java\android\telephony\SignalStrength.java getLevel( )函数，该函数是主要用来获取信号的强度。 public int getLevel() { int level; if (isGsm) { level = getLteLevel(); if (level == SIGNAL_STRENGTH_NONE_OR_UNKNOWN) { level = getGsmLevel(); } } else { int cdmaLevel = getCdmaLevel(); int evdoLevel = getEvdoLevel(); if (evdoLevel == SIGNAL_STRENGTH_NONE_OR_UNKNOWN) { /* We don't know evdo, use cdma */ level = cdmaLevel; } else if (cdmaLevel == SIGNAL_STRENGTH_NONE_OR_UNKNOWN) { /* We don't know cdma, use evdo */ level = evdoLevel; } else { /* We know both, use the lowest level */ //level = cdmaLevel < evdoLevel ? cdmaLevel : evdoLevel; level = cdmaLevel > evdoLevel ? cdmaLevel : evdoLevel; } } if (DBG) log("getLevel=" + level); return level; } public int getLevel() { int level; if (isGsm) { level = getLteLevel(); if (level == SIGNAL_STRENGTH_NONE_OR_UNKNOWN) { level = getGsmLevel(); } } else { int cdmaLevel = getCdmaLevel(); int evdoLevel = getEvdoLevel(); if (evdoLevel == SIGNAL_STRENGTH_NONE_OR_UNKNOWN) { /* We don't know evdo, use cdma */ level = cdmaLevel; } else if (cdmaLevel == SIGNAL_STRENGTH_NONE_OR_UNKNOWN) { /* We don't know cdma, use evdo */ level = evdoLevel; } else { /* We know both, use the lowest level */ //level = cdmaLevel < evdoLevel ? cdmaLevel : evdoLevel; level = cdmaLevel > evdoLevel ? cdmaLevel : evdoLevel; } } if (DBG) log("getLevel=" + level); return level; }getCdmaLevel( )获取CdmaLevel，同样也有getEvdoLevel( )函数，在上一个函数中，通过比较Evdo和Cdma的强度，来最终确定信号的显示强度，也就是我们在通知栏里看到的信号格数。 public int getLevel() { int level; if (isGsm) { level = getLteLevel(); if (level == SIGNAL_STRENGTH_NONE_OR_UNKNOWN) { level = getGsmLevel(); } } else { int cdmaLevel = getCdmaLevel(); int evdoLevel = getEvdoLevel(); if (evdoLevel == SIGNAL_STRENGTH_NONE_OR_UNKNOWN) { /* We don't know evdo, use cdma */ level = cdmaLevel; } else if (cdmaLevel == SIGNAL_STRENGTH_NONE_OR_UNKNOWN) { /* We don't know cdma, use evdo */ level = evdoLevel; } else { /* We know both, use the lowest level */ //level = cdmaLevel < evdoLevel ? cdmaLevel : evdoLevel; level = cdmaLevel > evdoLevel ? cdmaLevel : evdoLevel; } } if (DBG) log("getLevel=" + level); return level; } public int getLevel() { int level; if (isGsm) { level = getLteLevel(); if (level == SIGNAL_STRENGTH_NONE_OR_UNKNOWN) { level = getGsmLevel(); } } else { int cdmaLevel = getCdmaLevel(); int evdoLevel = getEvdoLevel(); if (evdoLevel == SIGNAL_STRENGTH_NONE_OR_UNKNOWN) { /* We don't know evdo, use cdma */ level = cdmaLevel; } else if (cdmaLevel == SIGNAL_STRENGTH_NONE_OR_UNKNOWN) { /* We don't know cdma, use evdo */ level = evdoLevel; } else { /* We know both, use the lowest level */ //level = cdmaLevel < evdoLevel ? cdmaLevel : evdoLevel; level = cdmaLevel > evdoLevel ? cdmaLevel : evdoLevel; } } if (DBG) log("getLevel=" + level); return level; }» 本文地址： http://velep.com/archives/1147.html » 文章出处： reille博客—http://velep.com , 如果没有特别声明，文章均为reille博客原创作品
|
【本文地址】
今日新闻 |
点击排行 |
|
推荐新闻 |
图片新闻 |
|
专题文章 |