Android: getallcellinfo()/getneighboringcellinfo() detects unknown cell info

[hzy11137]

I'm trying to get the information of the cell tower nearby in the Eclipse. And, I want to ask why can't I get the MCC, MNC, CI, TAC information (all are max value of Integer) of the non-registered base station nearby by using getAllCellInfo()? And why can't I get LAC and CID by using getNeighboringCellInfo()?


This is my codes of getAllCellInfo:
TelephonyManager mTelephonyManager = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
List<CellInfo> infos = mTelephonyManager.getAllCellInfo();

if (infos != null) {
if (infos.size() == 0)
return;
for (CellInfo i : infos) {
if (i instanceof CellInfoGsm) {
Log.i("Location", "Base Station(CellInfoGsm) Info Nearby: " + i.toString() + "\n");
} else if (i instanceof CellInfoCdma) {
Log.i("Location", "Base Station(CellInfoCdma) Info Nearby: " + i.toString() + "\n");
} else if (i instanceof CellInfoLte) {
Log.i("Location", "Base Station(CellInfoLte) Info Nearby: " + i.toString() + "\n");
} else if (i instanceof CellInfoWcdma) {
Log.i("Location", "Base Station(CellInfoWcdma) Info Nearby: " + i.toString() + "\n");
} else {
Log.i("Location", "Base Station(CellInfoGsm) Info Nearby: UNKNOWN" + "\n");
}
}
}
I test the codes above using Lenovo PB2-690Y(Android 6.0.1, API 23),but the results in the logcat is as follow:
10-10 11:48:28.090: I/Location(18765): Base Station(CellInfoLte) Info Nearby: CellInfoLte:{mRegistered=YES mTimeStampType=oem_ril mTimeStamp=948186856440416ns CellIdentityLte:{ mMcc=302 mMnc=720 mCi=24371977 mPci=457 mTac=33333} CellSignalStrengthLte: ss=19 rsrp=-103 rsrq=-7 rssnr=2147483647 cqi=2147483647 ta=2147483647}
10-10 11:48:28.090: I/Location(18765): Base Station(CellInfoLte) Info Nearby: CellInfoLte:{mRegistered=NO mTimeStampType=oem_ril mTimeStamp=948186856440416ns CellIdentityLte:{ mMcc=2147483647 mMnc=2147483647 mCi=2147483647 mPci=466 mTac=2147483647} CellSignalStrengthLte: ss=10 rsrp=-112 rsrq=-10 rssnr=2147483647 cqi=2147483647 ta=2147483647}

I also use the deprecated API --- getNeighboringCellInfo:

TelephonyManager mTelephonyManager = (TelephonyManager)getSystemService(Context.TELEPHONY_SERVICE);

List<NeighboringCellInfo> infos = mTelephonyManager.getNeighboringCellInfo();
StringBuffer sb = new StringBuffer("Total Number of Base Stations : " + infos.size() + "\n");
for (NeighboringCellInfo info1 : infos) {
sb.append(" LAC : " + info1.getLac());
sb.append(" CID : " + info1.getCid());
sb.append(" BSSS : " + (-113 + 2 * info1.getRssi()) + "\n");
}

Log.i("Location","Base station info "+sb);

I used the same configuration to test the old API, and the logcat result is :
10-10 12:22:26.565: I/Location(20670): Base station info Total Number of Base Stations : 1
10-10 12:22:26.565: I/Location(20670): LAC : -1 CID : -1 BSSS : 35