Develop Reference

TrafficStats API's getMobileRxBytes() and getMobileTxBytes() not working properly

The issue is known: when wifi is up, TrafficStats.getMobileRxBytes() and getMobileTxBytes() return 0 since Lollipop (https://issuetracker.google.com/issues/37009612).
I found a workaround ignoring zero values, except that on some devices (e.g Samsung 5G), when on wifi,  we get non-0 values. It brings only rmnet1 interface value traffic (rmnet1 is for VoLTE, rmnet0 for normal data).
1/ why only on Samsung devices? while it seems to be handled by Android OS
2/ another observation still on Samsung 5G devices (at least on Samsung S20): when wifi is down, cell counter (all cell traffic since boot: rmnet0 + rmnet1) is inconsistent, sometime we get a value V1, sometime a value V2 (different from V1)
A similar experience?

I haven't used 5G enabled devices, but as of i know, using NetworkStats.Bucket's object we can query for RxBytes and TxBytes with the help of querySummaryForDevice() which takes around 4 parameters
Connectivity(Mobile data, WIFI)
SubscriberID(here for OS 10+ we need to pass null and for previous versions we need to
pass subscriber id using TELEPHONY_SERVICE).
Starttime
Endtime.
you can get subscriberID using below code
private String getSubscriberId(Context context, int networkType) {
String deviceUniqueIdentifier = null;
if (ConnectivityManager.TYPE_MOBILE == networkType) {
TelephonyManager tm = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);
return tm.getSubscriberId();
}
return "";
}
This worked for me to get the RxBytes and TxBytes.

Android MCC and MNC

I'm trying to get the mcc and mnc after a SIM LOADED state, in order to check if the SIM card did change without READ PHONE STATE permissions, in order to disable the app requests for some networks and in some countries that the user do not want.
Since getSimOperator() may change according to the current carrier (e.g. when the user is on roaming or not) I decided to use the getNetworkOperator().
Although this method can return null even if the SIM is LOADED and may return different results e.g. a lycamobile card with GSM only connection is giving me mnc = 01 and when I take the SIM card out and put it again it gives me mnc = 04.
Does some one know why the mnc gives different results for the getNetworkOperator()? Which method is better, getNetworkOperator() or getSimOperator() for this case?
Also, I cannot use getResources().getConfiguration().mcc because it gives a int number which might remove the 0 before e.g. gives 4 instead of 04.
This is my code to check a SIM state change:
#Override
public void onReceive(final Context context, Intent intent) {
if (intent != null) {
Bundle extras = intent.getExtras();
if (extras != null) {
String ss = extras.getString(EXTRAS_SIM_STATUS);
if (ss != null && (ss.equals("LOADED"))) {
TelephonyManager telephonyManager = ((TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE));
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && hasPermissions(READ_PHONE_STATE)) {
//here I get the imsi
}else{
L.d("NetworkOperator result %s", telephonyManager.getNetworkOperator());
//saving in shared preferences in order to check if the sim is allowed or not
//this is also called on application onCreate() so I can check the current SIM
}
}
}
}
}
PS: the SIM card that I'm using only has GSM connection. Also I tried with an other card (with 4g capabilities) and everything works as expected the mnc is the same 01 for a vodafone card.

Let me share some information with you.. It may help.
MCC, MNC, PLMN
First, you must understand MCC and MNC:
MCC - Mobile Country Code
This is the country code. It always has 3 digits. Some countries can use more than one MCC.
MNC - Mobile Network Code
This is the network code. It can have 2 or 3 digits.
MCCMNC - PLMN Number.
Those numbers are used to differentiate one carrier from another one.
For example, you can check a list at www.mcc-mnc.com:
AT&T in US has following PLMN Number:
MCC = 310
MNC = 410
PLMN = 310410
Telefonica in Brazil, for example, has following PLMN Number:
MCC = 724
MNC = 10
PLMN = 72410
Based on the information above, we can imagine that we have PLMNs with 5 or 6 digits.
Since MNC can have 2 or 3 digits, I think you can retrieve the MNC number as follows (knowing that MCC always have 3 digits):
String plmn = "33402"; // OR 334020
String mcc = plmn.substring(0,3);
String mnc = plmn.substring(3,plmn.length());
System.out.println("plmn[" + plmn + "] mcc[" + mcc + "] mnc[" + mnc + "]");
All carriers in same country share the same MCC numbers. Some countries has more than one MCC... But even then, all carriers in that country uses one of that MCC.
So, if you want to check the location of some carrier, you must read its MCC (and never its MNC).
SIM and Network
One information stored in the simcard is that PLMN number. The PLMN number is retrieved from its IMSI. Its PLMN number are the 5 or 6 first digits of its IMSI.
This way, you can determine which carrier owns that SIMCard.
On the other rand, the network tower also broadcast its PLMN.
This way, an device can search for its HOME network every time you reboot you device (or move to another location).
HOME vs ROAMING
Home situation is when PLMN Number from the simcard is the same of the current registered network.
Roaming is when the SIMCard has a different PLMN than the registered cell.
Of course, some carriers has more than one PLMN Number and phone should be considered HOME in those situations. But this is another story.
Finally getSimOperator() and getNetworkOperator()
getSimOperator() This method returns MCCMNC (PLMN) from SIMCard
getNetworkOperator() This method returns MCCMNC (PLMN) from current camped Carrier
It is up to you
Now, you know the difference between simcard and network operator. So, you have to decide how to block/allow your app.
If you block by getSimOperator() you are blocking the simcards from a specific country. This way, regarless the registered cell, feature will remain blocked (even if the user is travelling to a country with the feature enabled).
If you block by getNetworkOperator() you are blocking the feature in specific networks/Contries. This way, if the user which can use the app, may have issues when he travells to a country where the feature is blocked.

LTE signal ASU level always 97

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 :-/

Estimating beacon proximity/distance based on RSSI - Bluetooth LE

I've got a simple iOS app which displays the proximity of the Bluetooth LE beacons it detects using such expressions as "immediate", "near" etc. and I need to write something similar on Android.
I've followed the tutorial at Android developer and I'm able to list detected devices and now want to estimate the distance/proximity - this is where it's become a problem. According to this SO thread it's just a handful of mathematical calculations. However, they require me to provide a txPower value.
According to this tutorial by Dave Smith (and cross-referencing with this Bluetooth SIG statement), it should be broadcast by the beacon devices as an "AD structure" of type 0x0A. So what I do is parse the AD structures and look for the payload of the one that matches the type.
Problem: I've got 4 beacons - 2 estimotes and 2 appflares. The estimotes don't broadcast the txPower at all and the appflares broadcast theirs as 0.
Is there anything I'm missing here? The iOS app seems to be handling it all without any problem, but using the iOS SDK it does it behind the scenes so I'm not sure how to produce the exact same or similar behaviour. Is there any other way I could solve my problem?
In case you'd like to take a look at the code I'm using to parse the AD structures, it's taken from the aforementioned Dave Smith's github and can be found here. The only change I did to that class was add the following method:
public byte[] getData() {
return mData;
}
And this is how I handle the callback from the scans:
// Prepare the callback for BLE device scan
this.leScanCallback = new BluetoothAdapter.LeScanCallback() {
#Override
public void onLeScan(final BluetoothDevice device, int rssi, byte[] scanRecord) {
if (!deviceList.contains(device)) {
MyService.this.deviceList.add(device);
Log.e("Test", "Device: " + device.getName());
List<AdRecord> adRecords = AdRecord.parseScanRecord(scanRecord);
for (AdRecord adRecord : adRecords) {
if (adRecord.getType() == AdRecord.TYPE_TRANSMITPOWER) {
Log.e("Test", "size of payload: " + adRecord.getData().length);
Log.e("Test", "payload: " + Byte.toString(adRecord.getData()[0]));
}
}
}
}
};
And what I see in the console is:
04-01 11:33:35.864: E/Test(15061): Device: estimote
04-01 11:33:36.304: E/Test(15061): Device: estimote
04-01 11:33:36.475: E/Test(15061): Device: n86
04-01 11:33:36.475: E/Test(15061): size of payload: 1
04-01 11:33:36.475: E/Test(15061): payload: 0
04-01 11:33:36.525: E/Test(15061): Device: f79
04-01 11:33:36.525: E/Test(15061): size of payload: 1
04-01 11:33:36.525: E/Test(15061): payload: 0

The txPower mentioned by #davidgyoung is given by the formula:
RSSI = -10 n log d + A
where
d = distance
A = txPower
n = signal propagation constant
RSSI = dBm
In free space n = 2, but it will vary based on local geometry – for example, a wall will reduce RSSI by ~3dBm and will affect n accordingly.
If you want the highest possible accuracy, it may be worthwhile to experimentally determine these values for your particular system.
Reference: see the paper Evaluation of the Reliability of RSSI for Indoor Localization by Qian Dong and Waltenegus Dargie for a more detailed explanation of the derivation and calibration.

double getDistance(int rssi, int txPower) {
/*
* RSSI = TxPower - 10 * n * lg(d)
* n = 2 (in free space)
*
* d = 10 ^ ((TxPower - RSSI) / (10 * n))
*/
return Math.pow(10d, ((double) txPower - rssi) / (10 * 2));
}

It is unclear whether your inability to read the "txPower" or "measuredPower" calibration constant is due to the AdRecord class or due to the information being missing from the advertisements you are trying to parse. It doesn't look to me like that class will parse a standard iBeacon advertisement. Either way, there is a solution:
SOLUTION 1: If your beacons send a standard iBeacon advertisement that includes the calibration constant, you can parse it out using code in the open source Android iBeacon Library's IBeacon class here.
SOLUTION 2: If your beacons DO NOT send a standard iBeacon advertisement or do not include a calibration constant:
You must hard-code a calibration constant in your app for each device type you might use. All you really need from the advertisement to estimate distance is the the RSSI measurement. The whole point of embedding a calibration constant in the transmission is to allow a wide variety of beacons with quite different transmitter output power to work with the same distance estimating algorithm.
The calibration constant, as defined by Apple, basically says what the RSSI should be if your device is exactly one meter away from the beacon. If the signal is stronger (less negative RSSI), then the device is less than one meter away. If the signal is weaker (more negative RSSI), then the device is over one meter away. You can use a formula to make a numerical estimate of distance. See here.
If you aren't dealing with advertisements that contain a "txPower" or "measuredPower" calibration constant, then you can hard-code a lookup table in your app that stores the known calibration constants for various transmitters. You will first need to measure the average RSSI of each transmitter at one meter away. You'll then need some kind of key to look up these calibration constants in the table. (Perhaps you can use the some part of the string from the AD structure, or the mac address?) So your table might look like this:
HashMap<String,Integer> txPowerLookupTable = new HashMap<String,Integer>();
txPowerLookupTable.put("a5:09:37:78:c3:22", new Integer(-65));
txPowerLookupTable.put("d2:32:33:5c:87:09", new Integer(-78));
Then after parsing an advertisement, you can look up the calibration constant in your onLeScan method like this:
String macAddress = device.getAddress();
Integer txPower = txPowerLookupTable.get(macAddress);

use the getAccuracy() method in the library, it gives you the distance of the beacon

Visualize the wifi signal strength

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.