I was wondering if you can set signal strength parameters. In andriod.telephony class I only see methods which get you the values, however, is it possible to set values too ?
No. Signal strength is a measurement of a physical thing- the ratio of signal to noise of the cellular signal. You can't set that- it is whatever it is. You can set its variable to 1 billion, it won't effect the physical reality. The only use of it would be to lie to other apps about what the real signal strength is. And no, there is no way to do that.
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I would like to get the overall signal strenght received with the mobile antenna. Ideally, I would love to get the electric field measured with my phone antenna.
I did found a lot of methods to get the signal strength but they all give a specific signal strenth (either GSM, Wifi, GPRS ...) but not the overall signal. Moreover, if there are no SIM card in the phone, the GSMsignalStrength will return 0 or null and even if there is a SIM card, I will only get the strength of the signal of that operator only.
Could you please help me?
I am building an application that collects the RSSI levels of APs around me and do some calculations based on that.
The problem is that the readings are unstable even if the device is still. For example, signals from an access point fluctuates between -71, -68,-75 and so on....
Is there a way to stabilize the signals?
In telecommunications, received signal strength indicator (RSSI) is a measurement of the power present in a received radio signal.
I think the best you can do is count them al together and devide them after a x amount of measssure time. (since you would never get an 100% accurate acces point because of al kinds of components).
source:
http://en.wikipedia.org/wiki/Received_signal_strength_indication
"The problem is that the readings are unstable even if the device is still. For example, signals from an access point fluctuates between -71, -68,-75 and so on...."
This is the nature of the wireless signal. Even if the device is still, the environment is "moving", so, the signal is suffering from small scale fading mostly due to the environment scatterers. So, it is normal to obtain these fluctuations in the device measurements.
The accurancy of each Android device Wi-Fi measurement is another story.
Moreover, keep in mind that the values returned are in dBm which means that is in mWatt but expressed in the log scale. So, as Thealon proposed the averaging, you have to be careful because you cannot devide dBm values.
one solution would be to convert the dBm values back to mWatt and then perform the averaging. like below
Convert dBm to mWatt: mWatt = 10^(dBm/10)
When getting the RSSI, Google recommends to:
Use calculateSignalLevel(int, int) to convert this number into an absolute signal level which can be displayed to a user.
Official Docs
Is there anyway to get current signal strength on Android device. I know there is a way where you can listen for signal strength change, but i cannot wait and need to know the current signal strength.
Any help would be appreciated.
Regards,
B
You can register the PhoneStateListener and save the last updated value into a variable and access it whenever you need it. It is the closest approximation of signal strenght you can get in real time.
you can download https://play.google.com/store/apps/details?id=com.nolanlawson.logcat&hl=en
from the app store on your device and while you move in and out of an ssid it will show you the signal strength pretty accurately. Hope this helps. Cheers.
Would like to determine via code whether the voice channel on an Android is experiencing noise.
There is a list of functions at http://developer.android.com/reference/android/telephony/SignalStrength.html
I see a function getGsmBitErrorRate() and that will be useful when I switch to GSM.
I see the function getEvdoSnr() but I think that is only for the "data channel."
The only other function with CDMA is getCdmaEci0(). How can one derive SNR from Eci0()?
Is there some other way of deriving this value?
Review: I'm looking for a function that returns something like Bit Error Rate OR a Signal to Noise Ratio. I find one link that implies that ec/i0 is exactly the same thing as SNR.
But other pages have indicated that ec/i0 is the amount of signal that is available.
Ec refers to the pilot signal energy. Io refers to the noise energy. Thus, Ec/Io is the "pilot-to-noise ratio", instead of the "signal-to-noise ratio" (i.e. SNR). While, strictly speaking, the PNR is not the same as the SNR, as a practical matter you should be able to use the PNR as a proxy for the SNR. The whole point of the pilot is to give the receiver information about the signal and allow it to estimate channel effects.
This web page looks useful- Ec/Io.
Edit: I forgot that there is a parameter set by the network provider that specifies what the power of the pilot should be as compared to the actual signal. For instance, they could be the same power, in which case Ec/Io would be equal to the SNR, or the pilot could be half the power of the signal, in which case the SNR would always be 3 dB higher than Ec/Io. The pilot to signal ratio can be any of a number of different values and is, as mentioned earlier, set by the network. I don't recall what the parameter is called.
Question is as simple as the title: How to measure GPS signal strength?
Are you sure you mean signal strength vs. accuracy? What good is the signal strength? Since the GPS position is determined via many satellites, you don't have "one" signal strength.
So assuming that you really mean signal strength, you can get the GpsStatus via LocationManager.getGpsStatus(), and that gives you a list of satellites via getSatellites()', and each one of those has a signal-to-noise ratio (getSnr()).
Assuming you mean accuracy, try Location.getAccuracy().
You can read signal strength in MNEA message GSV in SNR-Signal to Noise Ratio.
Signal strength is VERY important. Too weak of a signal and the receiver can't track them. You need several 'strong' satellites to get position, not just one.
Older receivers couldn't track in trees or inside buildings. Modern receivers are much more sensitive.
It is very difficult to measure the signal level of a gps satellite without very expensive test gear (spectrum analyzer or specialized gps receiver). There are no commercially available tools to do this.
Why would you want to do this, anyway? The signal level is actually quite irrelevant in determining position.