# Which cell tower am I connected to?

• posted

There are apps which report the exact cell tower that you're connected to at any given moment but which of the identifiers that these apps provide tells me the exact cell tower and sector antenna unique identifier?

The stress of this question is on the word "unique" since just knowing the cell tower location in an Internet lookup database is not as useful as knowing the exact identifier for the exact sector antenna connection.

This is an example of the sets of numbers which these apps report.

There is a mobile tower TAC, PCI, ECI & EARFCN reported by these apps.

What is the minimum combination of those identifiers that is exactly the unique sector antenna the phone is currently connected to?

• posted

As shown in this example, every phone can report where it is and exactly what sector antenna on what tower by what carrier it is connected to.

MY LOC = 60.384528/56.850208 Serving Cell TAC = 26566 Serving Cell PCI = 31 Serving Cell ECI = 170572549(666299-5) Serving Cell EARFCN = 3300/21300 Serving Cell FREQ = 2675/2555 Serving Cell BAND = 7(FDD) My current RSRP = -99 dBm

As compared to this phone which also knows all that same identifying data.

MY LOC = -3.247542/55.976644 Serving Cell TAC = 35088 Serving Cell PCI = 349 Serving Cell ECI = 129457524(505693-116) Serving Cell BANDWIDTH = 5 MHz Serving Cell EARFCN = 39250 Serving Cell FREQ = 2360 MHz Serving Cell BAND = 40(TDD) My current RSRP = -93 dBm

I was hoping others would know this already so looking each of those indicators up to better understand which are the minimum unique set.

The TAC is the Type Allocation Code. Used to create the first 8 digits of the International Mobile Equipment Identity (IMEI), the number that identifies each unique mobile device on all gsm networks.

The PCI is the Physical Cell Id. This is the identifier of a network cell in the physical layer. This property is limited to 504 values, and therefore needs to be reused in the network. If the PCI assignment is poorly planned, the risk for network conflicts is high.

The ECI is the Extended Cell identification or ECGI (Global). This number consists of the MCC, MNC, eNodeB and Cell ID.

The CGI is the Cell Global Identification for a Base Transceiver Station in mobile phone networks. This number is used in the GSM and UMTS networks and is a combination of the MCC, MNC, LAC and the CI.

The MCC is the Mobile Country Code. The mobile country code consists of three decimal digits and the mobile network code consists of two or three decimal digits (for example: MNC of

001 is not the same as MNC of 01). The first digit of the mobile country code identifies the geographic region as follows (the digits 1 and 8 are not used):

0: Test networks

2: Europe 3: North America and the Caribbean 4: Asia and the Middle East 5: Australia and Oceania 6: Africa 7: South and Central America 9: Worldwide (Satellite, Air?aboard aircraft, Maritime?aboard ships, Antarctica)

The MCC is used in combination with an MNC (a combination known as an "MCC/MNC tuple") to uniquely identify a mobile network operator (carrier) using the GSM (including GSM-R), UMTS, LTE, and 5G public land mobile networks. Some but not all CDMA, iDEN, and satellite mobile networks are identified with an MCC/MNC tuple as well.

The MNC is the Mobile Network Code. The Mobile Network Code is a unique two- or three-digit number used to identify a home Public Land Mobile Network (PLMN). MNC is allocated by the national regulator. A MNC is used in combination with the Mobile country code to derive the Home Network Identity (HNI).

The LAC is the Location Area Code. The LAC is the unique number given to each location area within the network. The served area of a cellular radio access network is usually divided into location areas, consisting of one or several radio cells.

The eNodeB is the Enhanced NodeB which references a group of antennas on a cell tower. The eNodeB alone does not identify the sector. To identify the sector or direction the specific antenna faced, you'll need to refer to the Cell ID.

The GSM Cell ID is the Cell Identity. It 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.

The EARFCN is the E-UTRA Absolute Radio Frequency Channel Number. In LTE, the carrier frequency in the uplink and downlink is designated by EARFCN, which ranges between 0-65535. EARFCN uniquely identify the LTE band and carrier frequency.

From that information which every phone easily reports, I should be able to deduce the exact sector antenna used by any one connection at any given time.

Specifically, if I have multiple people at the same place, each of us should be able to instantly determine which unique sector antenna each of us is connected to.

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