A blast from the past: Ericsson I888

[Mychaela Falconia]

Hello FreeCalypso community,

As most of you probably know, our beloved TI Calypso platform dates
from the mid-2000s: the chipset of Calypso C035 DSP36 plus Iota ABB
plus Rita RF dates from 2004, whereas most commercial Calypso phones
(Mot C1xx, Pirelli DP-L10, Huawei and iWOW modules) date from 2005 to
2007 timeframe.  However, the era of "most classic" GSM phones (think
Nokia DCT3 family, Ericsson I888 etc) was some years earlier, in the
late 1990s - that late 1990s period can perhaps even be called the
Golden Age of GSM.

Now that I have my own GSM network for full-freedom testing, I am
making a little side venture to enrich my understanding of history: I
am acquiring some GSM phones (specifically PCS1900 band models, or
multiband ones that include PCS1900) from that late 1990s golden era,
I bring them up on my Themyscira Wireless network, and I get a feel
for how they function, particularly in comparison to mid-2000s phones
which I have more experience with.

The first 1990s phone in my collection, acquired just a few days ago,
is Ericsson I888 World.  This model is a good example of what the term
"high end phone" meant in late 1990s - it is a very solid device, big
and heavy as a brick.  This "world phone" supports just two bands,
900 MHz and PCS1900 - note the lack of DCS1800 support - but back then
multiband support was an expensive proposition, requiring large parts
of the RF tract to be replicated per band.  At the same time as this
900+1900 MHz I888, Ericsson also had a 900+1800 MHz sibling called
SH888 - I heard about SH888 being popular in Russia in those days, but
naturally it was never found in USA, lacking PCS1900 band support.

This Ericsson phone appears to be based on an earlier technology
generation than Nokia DCT3 family, even though chronologically they
seem to be contemporaries.  I don't have any DCT3 phones yet (plan to
acquire some, to round out my collection), but some years ago I found
Nokia's service manual for "NSE-3 Series", and according to this
manual, those DCT3 phones already ran on 2.8V internally: their MAD
baseband, their RF block, etc were all powered at 2.8V.  The battery
was a choice of single-cell Li-ion or 3-cell NiMH, both considered
3.6V nominal.  But Ericsson I888 is a higher-voltage beast: it is
powered by a 4-cell NiMH battery (4.8V nominal), the scant service
manual (much less detailed than Nokia's, unfortunately) mentions
expected voltages at a few points, and according to that manual, this
very old phone has a baseband running at 3.2V and an RF section
running at 3.8V.

But aside from internal component evolution in terms of reducing size,
weight and power demands, there is remarkably little difference in end
user functionality between the awe-inspiring Ericsson I888 and our
beloved Calypso: I888 already supports both SIM and "on the phone"
phonebook storage, SMS with both storage options once again, and even
CSD calls.  It has an IR port, presumably proper IrDA, one can
presumably do CSD either through this IrDA port or through the wired
UART interface on the "system" connector (the kind with many little
pins), and there are references to Windows software for manipulating
phonebooks and SMS - hence there must be an AT command interface in
there.  All this stuff, already there in late 1990s!

I see these late 1990s high-end phones like this I888 model as the
inspiration for what we need to build in FreeCalypso.  As I see it,
the point in history at which things went wrong was when those 1990s
Classic phone manufs, Nokia and Ericsson and others, decided to keep
their electronic circuit designs and firmware source proprietary - if
classic dumbphone firmwares had been made Free Software back then, the
world would have been a much better place.  It is now our mission in
FreeCalypso to rectify that mistake - yes, we are 25 y too late, but I
say better late than never.

It is now late hour on my side of the world and I am getting tired, so
I won't write much more this time, but I thought I would share my
excitement about being able to play with a truly vintage phone and
actually get it up and running on my own GSM network.

Speaking of my GSM network, as in Themyscira Wireless: I still haven't
built the gateway between OsmoMSC's MNCC interface and PSTN, hence we
still haven't got outside connectivity - right now it's just calls
from one Themyscira phone to another with made-up "extension" numbers,
rather than real NANP.  I still like the plan of using bulkvs.com
service for real 10-digit NANP numbers and PSTN connectivity via SIP,
but I have some rather unconventional ideas for how I would like to
tie all this stuff in terms of software stack - I will write more
later.

Hasta la Victoria, Siempre,
Mychaela aka The Mother