Cell Tracker

For an Android app that displays cell phone base station information, install CellTracker.

CellTracker.apk (for Android S and 12.0) (experimental version for Android S, compatible back to Android 8.0)

CellTracker.apk (for Android 11.0 and up) (version for Android 11, compatible back to Android 8.0)

CellTracker.apk (for Android 10.0 and up) (version for Android 10, compatible back to Android 6.0)

The above versions may not work for you if you have an older system, in which case install instead:

CellTracker.apk (for Android 8.0 and up) (compatible back to Android 5.0)

CellTracker.apk (for Android 7.0 and up) (compatible back to Android 4.2)

If you have an even older version of Android then you may want to use an earlier version of the app (which will be backward compatibe to an even earlier API level).

CellTracker.apk (for Android 6.0 and up)

CellTracker.apk (for Android 5.0 and up)

CellTracker.apk (for Android 4.4 and up)

CellTracker.apk (for Android 4.2 and up)

CellTracker.apk (for Android 3.0 and up)

CellTracker.apk (for Android 2.2 and up)

Supplied “as is” — no warranty implied.

Information displayed on screen by line number — note that earlier versions have fewer lines than the current version (most of the screen shots above are from older versions):

(1) Voice connection type, Base station ID, (BID/CID in hex), — guess at direction to antenna, passing sense, lines written.

    Voice connection type is: CDMA or GSM.
    Base Station ID is SID:NID:BID for CDMA, or MCC:MNC LAC:CID for GSM.
    Direction to antenna (if known) (SW, NW, or E) - estimated direction to the base station sector antenna (±90°).
    Passing sense (if known), ‘L’ for left or ‘R’ for right — which side of one's path the tower was on.
    Shows ‘N/A’ if there is no voice connection (e.g. VoLTE)

(2) Voice connection type, signal strength (dBm + EcIo for CDMA, or ASU + BER for GSM)

    Shows ‘N/A’ if there is no voice connection (e.g. VoLTE)

(3) Data connection type, signal strength (dBm + SNR), data technology:

   for CDMA data: eHPRD, EVDOA, or 1xRTT;
   for GSM data: UTMS, HSPA+, HDSPA, EDGE, or GPRS.
   for LTE shows instead EARFCN and TimingAdvance (TA) — if available (§)(@)

(4) Provider of location data (GPS, WiFi, Cell, or Network) — latitude, longitude — and altitude (in m) (if provided).

(5) Accuracy (m), speed (m/sec) and azimuth (degrees) (if provider is GPS or ‘Fused’), satellites used in solution/satellites tracked.

(6) CDMA latitude and CDMA longitude of base station if provided by base station (+);
    otherwise MCC:MNC and network operator;

(7) Google geolocation of voice connection, and spread (in m) of area covered by corresponding base station antenna.

(8) Google geolocation of data connection, and spread (in m) of area covered by corresponding base station antenna.

(9) Local IP address, external IP address (if available).

(10) Power source (BAT, USB, or PWR), battery percentage, voltage, temperature and technology.

(11) For LTE data connection: base station ID: TAC, CI, and PCI (*)(@)

(12) For LTE data connection: SignalStrength, RSRP, RSRQ, RSSNR, CQI (*)(@)

(13) For LTE data connection: band, frequency (DL) and frequency (UL)(*)(@)

Each line ends with a “spinner” which changes when something on that line changes.
 (The spinners cycle through the sequence of symbols: |, /, -, \).

The icons in the “Action Bar” are coded as follows:
   Yellow star → Show version info;
   Blue double up arrow → Save data in file and start new CSV file;
   Magenta blob → hide “Action Bar” (long click on first line of text to put it back)
   Red cross → Exit CellTracker
   Vertical ellipsis → ‘More’ Menu (⋮)

Additional settings are acccessible from the ‘More’ Menu (⋮).

Some overlays may be shown on the map:
  Small blue circle - where your phone thinks it currently is;
  Light red circle (if present) - where the voice base station is (+) (†);
  Transparent orange disc - approximate spread of locations covered by the voice connection base station (if available).
  Transparent blue-green disc - approximate spread of locations covered by the data connection base station (if available).

If you touch the light red circle, or a transparent colored disc, information will be shown about that item in text form, including the ID of the base station and the geographical coordinates.


(*) Lines tagged with an asterisk require Android 4.2 or later (i.e. API level 17)
 and may not be fully implemented on some phones and some versions of Android
 (in particular, for LTE, PCI, RSSNR, CQI, and TA may not be known or wrong and shown as -1 or *).

(§) Absolute Radio Frequency Channel Numbers (EARFCN e.g.) require Android 6.1 (i.e. API Level 24).

(+) Base station location is available for CDMA — but only if the carrier provides it:
 U.S. Cellular does encode it (yeah!),
 Verizon Wireless does not (boo!).
 SPRINT does provide a location, but it is the average of places where signals from the antenna are received rather than the location of the antenna itself — and this will change a bit with time as it is updated (sigh).

(†) If the base station location is known, and it is possible to guess which of three sector anntenas is being used, then a red half circle will be used to indicate roughly in which directions signals from that antenna are likely to be aimed.

(‡) If it is possible to guess which of three base station sector anntenas is being used, then the cat footprint will be rotated to point more or less away from the base station.

(@) In the case of LTE carrier aggregation, the information shown is about the first registered LTE connection.

NOTE: The screen dims after a while to conserve battery power. (A short screen touch makes it bright again).
 A long click on one of the last few text lines dims the screen right away.

NOTE: CellTracker keeps the GPS on while in the foreground and so will increase battery drain —
 it helps to be plugged into a USB cord or charger.

See also

A brief tour of the world of cellular repeater antennas

Outside antennas for cellular repeaters

Berthold K.P. Horn, bkph@ai.mit.edu