GSM Cell ID

A GSM Cell ID (CID) is a generally unique number used to identify each base transceiver station (BTS) or sector of a BTS within a location area code (LAC) if not within a GSM network.

In some cases the first or last digit of CID represents cells' Sector ID:

• value 0 is used for omnidirectional antenna,
• values 1, 2, and 3 are used to identify sectors of bisector or trisector antennas.

In UMTS, there is a distinction between Cell ID (CID) and UTRAN Cell ID (also called LCID). The UTRAN Cell ID (LCID) is a concatenation of the RNC-ID (12 bits, ID of the Radio Network Controller) and Cell ID (16 bits, unique ID of the Cell). CID is just the Cell ID. The concatenation of both will still be unique but can be confusing in some cellid databases as some store the CID and other store LCID. It makes sense to record them separately as the RNC ID is the same for many cells, the unique element is the CID.^{[citation needed]}

A valid CID ranges from 0 to 65535 (2¹⁶ − 1) on GSM and CDMA networks and from 0 to 268,435,455 (2²⁸ − 1) on UMTS and LTE networks.^[1]

Cell ID databases and services

A number of commercial and public Cell ID databases and services are available:

Name	Unique cells	Countries (MCC)	Operators (MNC)	Measurements	Free database download	Active project	Data license	Comment
Cell Spotting	0.1 million[2]		667			no	CC0
Combain Mobile	>140 million[3]	>240	>1700	>131 billion	no	yes		Supports GSM, CDMA, UMTS, LTE and NR via API.[4]
LocationAPI.org	157.89 million[5]	240	1712	25 billion	no	yes		Supports WiFi, GSM, CDMA, UMTS and LTE technologies via its API. Unwired Labs LocationAPI Global Coverage Map [6]
Mozilla Location Service	28.2 million[7]	240[8]		2.7 billion[7]	yes[9]	no[10]	CC0[9]	Based on crowd-sourced data. Also WiFi database. Cooperating with OpenCelliD[9] and Combain.[11]
Mylnikov GEO[12]	>34 million	505	3500		yes	no[13]		Contains data from radiocells.org, OpenCellID and MLS.
Navizon[14]	71 million	239	1712	22 billion	no	yes		Based on crowd-sourced data. Also WiFi database.[15]
NetMeterProject.com	0.2 million	77	174	10 million	limited; private use only	no [16]		Only a small portion of the database can be downloaded and for private use only: the measurements where the crowd users accepted the "Creative Commons Namensnennung-Nicht-kommerziell-Weitergabe unter gleichen Bedingungen 3.0 Deutschland" license
OpenCellID by Unwired Labs[17]	38.9 million	222	753	2.1 billion	yes	yes	CC-BY-SA 3.0	OpenCellID database growth monthly Based on crowd-sourced data; free API key required for database download; Service is now maintained by Unwired Labs.[18]
OpenSignal[19]	0.8 million		825	5.2 billion	no	yes
radiocells.org[20]	0.7 million	94	243		yes	yes	CC-BY-SA 3.0	Based on crowd-sourced data.
WiGLE[21]	6.2 million				no	yes
CellMapper					no	yes
OpenMobileNetwork
G-NetWold by Gyokov Solutions
Skyhook Wireless
Google Location Services[22]
Apple Location Services[23]
Microsoft Location Services[24]

See also

• Base transceiver station
• Field test mode
• E-CellID