i went though the following post to get the signal strength in android:
How to get cell service signal strength in Android?
my ques is that: how does the signal strength gets updated to the system UI. what does each bar in the strength meter signify? is there a particular threshold value for each bar?
The signal strength icon is controlled from SystemUI. It might differ in other Android versions, but in KitKat the NetworkController.java class handles which icon is shown. The SignalStrength.java is the class that returns to NetworkController.java what the current signal strength is. The signal strength is represented as a number between 0 (no signal) and 4 (great signal). The actual signal is measured in dBm, and is passed into the SignalStrength.java class as a Parcel from the (low level) radio interface layer (RIL) of the Android framework. The actual thresholds differs between the different radio technologies used.
The getGsmLevel() function in SignalStrength.java does the trick here:
int level;
int asu = getGsmSignalStrength();
if (asu <= 2 || asu == 99) level = SIGNAL_STRENGTH_NONE_OR_UNKNOWN;
else 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;
this function returns the level
Related
I am looking to create an app that gets information about the phones connection to the cellular network.
My understanding is that RSSI is a measure of cellular signal with GSM and RSRP is a good measure for LTE.
To keep it consistent, is it possible to get a RSSI measure for LTE?
I am confused about what classes to use to get some of this information. At the moment, I am using the phone state listener which gives me a SignalStrength object. Using this object, I can call the two string method that provides me the following information when i split it. I am a little confused on what some of this means.
String ssignal = signalStrength.toString();
String[] parts = ssignal.split(" ");
The parts[] array will then contain these elements:
part[0] = "Signalstrength:" _ignore this, it's just the title_
parts[1] = GsmSignalStrength
parts[2] = GsmBitErrorRate
parts[3] = CdmaDbm
parts[4] = CdmaEcio
parts[5] = EvdoDbm
parts[6] = EvdoEcio
parts[7] = EvdoSnr
parts[8] = LteSignalStrength
parts[9] = LteRsrp
parts[10] = LteRsrq
parts[11] = LteRssnr
parts[12] = LteCqi
parts[13] = gsm|lte|cdma
parts[14] = _not really sure what this number is_
What is part 8 providing? RSSI?
Also, when you look at the signal strength in the android settings, it gives you the RSSI for GSM. When connected to LTE, is it giving us the RSRP or RSSI? It seems its providing RSRP.
My understanding is that part[1] provides the RSSI when connected on GSM. However, i am unsure, and interested about, part[2] (what is the rate measured against? what unit of time), part[8] (what does it measure exactly?), part[10] and part [11](what unit is it measured in and what is the unit range)
I understand this thread is all over the place. Hopefully it makes a little bit of sense and someone can clear something up.
Cheers guys!
To put it simply, RSSI and RSRP are signal level measurements for GSM and LTE, respectively. They are not exactly the same, because GSM and LTE are very different technologies. However, they both indicate the same type of information. RSRP holds no meaning in GSM and RSSI means something different in LTE.
This question may be worth reading:
How to get LTE signal strength in Android?
Most of what you are looking for, I was able to find here: https://developer.android.com/reference/packages.html
GsmSignalStrength - GSM Signal Strength, valid values are (0-31, 99) as defined in TS 27.007 8.5
GsmBitErrorRate - GSM bit error rate (0-7, 99) as defined in TS 27.007 8.5
CdmaDbm - CDMA RSSI value in dBm
CdmaEcio - CDMA Ec/Io value in dB*10
EvdoDbm - EVDO RSSI value in dBm
EvdoEcio - EVDO Ec/Io value in dB*10
EvdoSnr - Signal to noise ratio. Valid values are 0-8. 8 is the highest.
I could not locate the following, but here is what I suspect:
LteSignalStrength - LTE Signal Strength in ASU (0-31, 99)
LteRsrp - LTE RSRP value in dBm
LteRssnr - LTE SINR value in dB
LteCqi - LTE CQI (no units)
gsm|lte|cdma - Network type
I am capturing the RSSI values of LTE signals using the below code:
cInfoList = telephony_manager.getAllCellInfo()
for (CellInfo info : cInfoList){
if (info instanceof CellInfoLte) {
CellSignalStrengthLte signalstrength_lte = ((CellInfoLte) info).getCellSignalStrength();
displayAsu.setText(signalstrength_lte.getAsuLevel() + "");
displayDbm.setText(signalstrength_lte.getDbm() + "");
}
}
(*note: I just simplified my code: for-loop doesn't override text fields.)
In one phone (LG G4) I am getting meaningful vales: Asu_level=32, dbm=-108
But in another phone (Samsung Galaxy S6) I am getting invalid values: Asu_level=97, dbm=1022
In Samsung phone's Settings->AboutPhone->Status->SignalStrength I see -107dBm 33 asu (which make sense)
LG G4: Android 5.1, API 22 and
Samsung Galaxy S6: Android 5.0.2, API 21
Why does the same code show different behaviors (Asu levels) on different phones?
The S6 appears to put corrupted signal level values in its CellInfoLte objects (and unset levels in its CellInfoCdma objects). https://github.com/Tombarr/Signal-Strength-Detector is an app which uses reflection to dump out a plethora of signal level related data. On my S6, I can see that SignalStrength (which is the parameter to the PhoneStateListener.onSignalStrengthsChanged callback) includes sane looking mCdmaDbm/mLteRsrp values. It's obviously less convenient and presumably more overhead to create a TelephonyManager listener but it looks like that's what it takes on this device :-/
iam developing an android app where i want to get the range of signal values for GSM and CDMA coverage. I am displaying the dbm values for GSM coverage using the below code
gsmStrength = String.valueOf(signalStrength.getGsmSignalStrength() * 2 - 113);
String phnstrngth = MyListener.getStrength() + "dBm";
The above code gives me the dbm values for GSM Coverage. Similarly i want to get the dbm values for CDMA Coverage. Not Getting how to do it! Please Help! Thanks!
It's actually simpler for CDMA because the API provides the signal strength in dBm:
cdmaStrength = String.valueOf(signalStrength.getCdmaDbm();
String phnstrngth = MyListener.getStrength() + "dBm";
I was able to scan all wifi networks with the wifimanager.getScanResults().
In the next step I extracted the SSID and signal level of the wifi network.
private List<String> showOnlySSIDAndLevel(List<ScanResult> networks) {
List<String> networkList = new ArrayList<String>();
for(ScanResult result : networks){
int level = WifiManager.calculateSignalLevel(result.level, 5) + 1;
String content = result.SSID + " \tSignal strength: " + level;
networkList.add(content);
}
return networkList;
}
I have the signal level in a format, where it's between 1 - 5 (5 is the best signal level)
How can I use this to have a graphical representation of the different wifi signal levels.
I coudn't find a UI for this. Do I need a graphic for each of the 5 possible level or is there another way? How is the internal Android Settings (Wifi scan results) doing it?
I think found a better option ...
imageView.setIcon(android.R.drawable.stat_sys_wifi_signal_<strength>)
where strength is a variable in the range of 0 to 4...
For more details refer to
http://androiddrawableexplorer.appspot.com/
You can use the built-in RatingBar component. You can make it read-only by giving it a ratingBarStyleSmall or ratingBarStyleIndicator style.
How to convert WiFi level (i.e. -45 , -88 ) in to percentage ?
I want to convert WiFi level in % . I get WiFi level using level ( in dBm format)
I try lot of google but not get proper ans
Problem with this is that is very dependent on the receiving antenna. Some antennas register no useable signal at -90 dBm, some already at -80. You will have a hard time finding 0% (100% strictly being 0dBm).
I have created a Wifi scanner application where I use -100dBm as 0% and 0dBm as 100%, in Java it turns into something like this (MIN_DBM being -100):
public int getPowerPercentage(int power) {
int i = 0;
if (power <= MIN_DBM) {
i = 0;
} else {
i = 100 + power;
}
return i;
}
This is what Microsoft does for dBm <> percent conversion:
https://stackoverflow.com/a/15798024/2096041
Basically -50 .. 0 dBm maps linear to 100 .. 0 %.
Like MS, i would prefer to sit on the safe side and not use -100 as 100% as some answers here suggest.
The WifiManager class has a function calculateSignalLevel, but as it states here, it results in an error if numLevels is greater than 45. Possible workaround could be something like this:
double percentage = WifiManager.calculateSignalLevel(int rssi, 40) * 2.5;
but of course, this will be in steps of 2.5 percents - I don't know your use case but maybe this is sufficient.
As others have stated, calculating percentages is problematic, and there's no simple precise solution for that.
You could derive the percentage from the signal-to-noise ratio, rather than the signal intensity alone, if this information is available. This is probably the desired metric.
An android.net.wifi.ScanResult does not publish the neccessary information (as of Dec 2012), but you might be able to get this information through other means.
Signal = Noise => unusable signal, so you could set 0dB SnR = 0%. Also you could set 10dB SnR to 90% (90% of the signal power is not drowned out in noise), and 100% = no noise at all. More generally,
p = 100% * (1 - 10^(SnR / (10dB)))