Hi guys
First of, anonymity and communication integrity is totally possible, but requires some level of expertise and systems think.
The guys over at Fort Galt in Chile (No, not Galt's gulch), is working on a decentralized cellphone service coupled with block-chain technology. They're also into other forms of long range communication.
With modern SDR (Software Defined Radio) any type of radio transceiver is possible, so long as the right amplifier and antenna is used. Setting up a pirate cellphone tower or creating your own pirate cellphone network is now almost kids play. Also remember that HF/CB radio bands for amateur radio is readily available,
Personally I play around with long range WiFi stuff for kicks and learning penetration testing as a tech-nomad skill.
Purism is soon to release Librem 5, a very secure phone highly anticipated in the geekosphere.
Blackphone and GeeksPhone are other projects working with PrivatOS that might interest you.
When using alternative operating systems for android devices, the most important thing to consider is to get a popular common phone that the operating system you choose have a good group of maintainers for. Some models have dedicated individual doing great just solo, but try to find this out before choosing phone or OS.
There are apps that will give out false GPS positioning, which at least helps so long as your phone is not triangulating cell towers while connected to a mobile net. Try to find an app that lets you toggle the mobile services on and off, and test that it works on your phone. Obviously using a VPN service when connecting over WiFi helps a lot.
A lot comes down to not using cloud services, but internalize as much data as possible, don't use mobile apps from google, adobe, youtube, facebook, twitter, whatsapp, skype or similar proprietary stuff, instead use their websites by using a browser set to request computer version of the websites. When possible use Matrix, KeyBase, Signal or Telegram for communication instead. Many XMPP clients are safe as well, such as Jabber. Rooting your phone makes you able to have full control of your pone and even Android can be made to behave safely, with the right root-apps, to have full control of what program are allowed to do what and what sensors it can use, and prompt you before using them, etc.
There has been several Linux based attempts at making systems for utterly paranoid people, but nothing comes even remotely close to Cubes OS, which entirely compartmentalize everything and anything you want. it's what I run on my penetration testing rig, A so called "GhostPad", a ThinkPad custom built by our fellow Voluntaryist and Agorist, Jamin Biconik, who have either physically replaced or circumvented various proprietary hardware parts, installed an Open Source BIOS alternative (seaBIOS plus Cooreboot/Libreboot) and sent it with Cubes, plus a bootable USB-stick with Tails as a proper amnesic option.
As a technical translator I work with the FreedomBox project, the pet project of Eben Moglen, the guy who drafted the original GPL licences. A Debian based OS and software stack made to run on small hardware or even tiny plug servers, devices like RasperryPi, Olimex boards, and alike (but works on any computer), as a home router, firewall and server that hosts all your personal data and services, such as mail, torrent-tracker, ftp-server, wiki, websites, tor nodes, and much more. this keeps all your personal data juridically under a different domain, as a search-warrant would be needed to access the data you keep in your own home. All this is strictly Open Source of course.
