Date:  2021-04-23
Time:  04:58:57 UTC
Title: My thoughts toward agk's 2G renaissance
In the past few weeks, my new SDF friend agk has posted several stories 
on her seasoned phlog about the future of 2G cellular communictions and 
its associated feature phones. You can find those posts here:

gopher://sdf.org:70/0/users/agk/phlog/2021-04-09-2gbts.txt

And here:

gopher://sdf.org:70/0/users/agk/phlog/2021-04-16-gprs.txt

Anna is proposing the reuse of phones that relied on 2G connectivity 
alone (no WiFi nor Bluetooth). This excludes BT pairing (e.g., Asterisk 
chan_mobile conversion of BT feature phones into Asterisk client 
handsets) and WiFi connections (for fast browsing, SIP, and SSH) as 
repurposing options. Fortunately, she reports that recent developments 
(OpenBTS - Open Base Transceiver Station - software combined with an 
inexpensive antenna dongle combination - $40 for an antenna and SDR) 
could bring 2G back, at least in short ranges (houses or city blocks). 

The challenges include repurposing of 2G radio spectra for other roles, 
permitted transmission ranges, and whether 2G speeds are sufficient for 
applications of interest (171kbps max for GPRS and 384kbps max for 
EDGE), from what I understand. This would certainly be fast enough for 
text-based applications (IRC, SSH/telnet, gopher) but would struggle for 
the next level up - internet audio (SIP on the low end and internet 
radio on the high end).

Toward the goal of making 2G phones useful on the modern internet, I 
have stockpiled small Java programs for these devices (MIDlets) 
collected from the various corners of the web on my home gopher server, 
here:

gopher://molleraj.homelinuxserver.org:70/1/midlets

These include email (Gmail), IRC (jmIrc), gopher (Pocket Gopher), SSH 
and telnet (midpssh), RSS (rssreader), internet radio (mradio), and web 
browsing (Opera Mini). These should work on phones that support J2ME, 
which were many in the days preceding the prevalence of smartphones and 
the new age KaiOS feature phones. They indeed would bring the textual 
internet world to compatible 2G phones. In the future I will look for a 
jabber/xmpp client, but Talkonaut may fit the bill.

Note from later on April 23: Anna told me that $40 SDRs would be 
receive only, so the cost is more realistically an order of magnitude 
higher ($300 for a LimeSDR Mini running Osmocom or YateBTS, $525 for a 
Ettus USRP B210 knockoff).