Where in the cell am I?

CellTrack is a neat little application for Series 60 mobile phones, like my Nokia N70, that displays information about the current “cell” in the network that the phone is connected to. Here’s a screen shot:

CellTrack Screen Shot

But what does all that stuff mean?

The first item, CellId, is “the id from the actual cell” says the CellTrack documentation. Add that to information from this useful page:

The last digit of the Cell ID is actually the sector number, and it will be 7, 8, or 9 on any 1900 MHz channel, and 1, 2, or 3 on any 850 MHz channel. The remaining digits are the CID shown in the list below. That means that if you see 22148 on your phone, the CID is 2214, and you are picking up sector 8 (which is a 1900 MHz channel). 22142 would be the same sector, but on an 850 MHz channel. Rogers are very methodical about their sector designations. Sectors 2 and 8 are the ones that face south, while sectors 1 and 7 face northeast, and sectors 3 and 9 face northwest.

Moving around town I see that the CellId varies through 7177, 7178 and 7179; this suggests that the “Cell ID” is 717, that it’s communicating on 1900 MHz, and that my phone is variously communicating with the south, northeast and northwest “sectors” of the cell. So I’m presuming this means that I’m talking to various bits of the same cell tower. Note that the 1C0B is just 7179 in hex.

The LAC of 1300 is said to be the “Location Area Code from your cell.” Obviously this isn’t my “area code” in the classic telephone sense (902); apparently it identifies “which general area you are in.” This is further explained in this document, which offers the definition (“PLMN” means “Public Land Mobile Network” or, in other words, “mobile phone company”):

a set of cells of a PLMN grouped together may for[m] a LA. A LA is identified by a LAC. A LA the smallest area where a MS can be paged. A LA is also the smallest area, which can be barred for roaming

The Net of 302 72 is a two-part code that, it says here is the “network code” for Rogers Wireless. The 302 is the “Mobile Country Code” for Canada; the 72 is the “Mobile Network Code” for Rogers.

I presume that those with access to Rogers cell databases can use this information to pinpoint my location somewhat. There are grassroots efforts to tie cell IDs to locations: here’s one for Australia, and this one and this one for Canada. And of course there’s the upcoming Plazes feature that uses the same data.

I welcome additional fleshing out of the information above by those who Know More.


Add new comment