Re: Understanding GSM BTS Tx power levels

Hi Caleb, Thanks for the explanation regarding "proper" BTS setups having much more sensitive antennas for receiving uplink. In my case, I will be operating my BTS indoors inside my apartment (no tower), it will be a sort of clandestine operation squatting on an unused frequency *without* the usual billion dollar license, and the antennas hooked up to the Tx & Rx ports on the indoor BTS will be the ordinary omnidirectional kind. At first I was thinking about using the same kind of 5 cm antennas as these ones sold by Sysmocom: http://shop.sysmocom.de/products/ant-sma-quad I have a big bag of SPK ECL antennas similar to the above, except that mine are the straight version - I use them with all of my GSM MS development boards - but now that I think about it, there is another antenna which probably has higher gain which I can probably use for the BTS: https://www.sparkfun.com/products/8347 If I use either of the above, the Rx and Tx antennas on my BTS will probably be a little better than the internal antenna built into most cellphones, but it will be comparable to the MS antenna if the MS is one of my development boards. :) The two BTS models I am currently considering as my top choices are either the PCS band version of ip.access nanoBTS (used from ebay) or sysmoBTS 1002, and both of these seem to have the same maximum Tx power output of 23 dBm. Am I correct in assuming that if my BTS puts out 23 dBm, then I will hit my range limit when the MS stops being able to hear the BTS, before I hit the limit in the uplink direction? Any guesses as to what kind of range I should expect? I don't expect that my illegal BTS will ever serve any users other than just me - as I understand it, the total number of people *on the entire planet* who would voluntarily wish to use a 2G phone (as opposed to 5G/whatever) will never exceed maybe 10 users max planetwide, and I am pretty certain that right now I am the only active 2G user in all of California, if not in all of USA. As of today, T-Mobile USA still has active 2G service across all parts of California which I frequent these days - my travels nowadays are much less than pre-Covid, but I still occasionally drive as far south as downtown San Diego and as far north as almost hitting LA, and so far I have working service almost everywhere. But I can only reason that all those GSM cells must sit there 100% idle with exactly zero traffic almost all of the time, except during those brief moments when I happen to drive by that cell in my car - I don't see how it can be any other way when absolutely everyone else has standard sheeple 4G/5G phones. The only T-Mobile 2G cell that has nearly constant activity on it is the cell that serves my apartment, as that is where I stay 99% of the time in this Covid-driven reality. Thus I can only reason that T-Mobile USA currently maintains a GSM/2G network that has *only one active user* perhaps in the entire country, so it is understandable that they are threatening to shut it down. If they shut it down before I kick the bucket, I am thinking of setting up my own illegal BTS (on the very same ARFCN on which wrongfully- shutdown T-Mobile service used to be) inside my apartment, connected to a VoIP tunnel on the back end. It won't help me at times when I have to drive somewhere, but it would be neat if it can cover areas within walking distance of my apartment - the two grocery stores in our little rural town both happen to be within walking distance. Sorry for ranting, Mychaela