Difference between revisions of "Talk:API"

Revision as of 03:16, 22 January 2015

LCID/CID

Warning when scanning 3G networks there's a clear distinction between CID and LCID. The LCID (long CID) is a concatenation of the RNC-ID (2 bytes, ID of the radio network controller) and CellID (4 bytes, unique ID of the Cell). CID is just the Cell ID. The concatenation of both will still be unique but can be confusing as some get the CID and not LCID. It would make sense to record them separately as the RNC ID is the same for many cells, the unique element is the CID. I noticed that opencellid database contains a mixture of LCID and CID (different contributions) and results in more cells than there are in reality for a given area. This may be sorted however by looking at the size.

If you install G-Mon app for Android for example, you will see that they provide both ID: the LCID and CID.

Reference: https://stackoverflow.com/questions/7240038/utran-cell-identity-returned-by-getcid

--Zorglub (talk) 17:24, 22 January 2014 (CET)

A different take on this:

While cell ID in 2G/GSM/GERAN is 16 bits (2 bytes = 4 semi-octets), in 3G/WCDMA/UTRAN it's 32 bits (4 bytes = 8 semi-octets). And yes, the leftmost 16 bits are the RNC-ID.

In fact, the RNC-ID is only 12 bits, so all hexadecimal representations of 3G cell IDs have a zero as the leftmost hex digit. The full cell ID is held in 28 bits (3GPP 25.331, section 10.3.2.2). That's 16 bits of "short cell ID" and 12 bits of RNC ID.

Error in the instruction

warning, there's an error in your instruction on http://wiki.opencellid.org/wiki/API#FAQ

There's no "br" in the minimal csv upload measurement example

--Zorglub (talk) 15:55, 23 February 2014 (CET)

<signal> in uploaded csv file - what units?

I'm regularly uploading data I gather. This includes signal level which I've been giving in dBm (eg -67).

But I notice in the examples that positive values of 3 and 4 are given. This obviously isn't dBm.

What is it? How do I convert to it from dBm? Or should I continue to provide the signal in dBm?

John

Clarification of "rating"

There's a field shown in the API labelled as "rating", could you clarify what this means, and how to use it?

E:V:A (talk) 17:44, 21 June 2014 (CEST)

This field stores the accuracy of the location (in meters). The Android Location service has getAccuracy() method ( http://developer.android.com/reference/android/location/Location.html#getAccuracy() ) which returns proper values. Please read the Android documentation for more details. --Msemm (talk) 10:11, 26 July 2014 (CEST)

Missing description of the returned items in CSV file

The table columns as shown in the CSV file in API#CSV does not clearly correspond to descriptions elsewhere on this page. The header row says: "lat,lon,mcc,mnc,lac,cellid,averageSignalStrength,range,samples,changeable,radio,rnc,cid,psc,tac,pci,sid,nid,bid", but these are ambiguous. For example, please describe the difference between: cellid and cid. And what is "range" etc etc? --E:V:A (talk) 05:22, 20 January 2015 (CET)

Negative values for "range" and "samples" in the CSV file for "list of cells in specified area"

There are several cells in your CSV file that has either one or both of "range" and "samples", as listed with a negative value. For example:

54.6704,25.256,246,2,10401,12861,-91,-1,15,1,GSM,,,,,,,,
54.6690,25.256,246,2,10401,11715,-65,344,37,1,GSM,,,,,,,,

What does it mean? --E:V:A (talk) 22:40, 21 January 2015 (CET)