[NCLUG] Data Through Cellular Technology?

[Michael Dwyer]

Marcio Luis Teixeira wrote:
> Where can I find some information decent information about wireless cellular 
> technology? AT&T's page (http://attws.com/) is overhyped and doesn't contain 
> useful information. I was able to glean some good information about the 
> various technologies from "wikipedia.com," but I'm not sure how it all 
> relates to AT&Ts royal mess of tradenames.

AT&T's data offerings don't seem that good to me.  I think the three you 
need to look at are Verizon, SprintPCS, and Voicestream->Tmobile.

AT&T uses a CDPD analog system, last I knew.  I think they are 
transitioning to a GSM interface, though.  I think this is the system 
that Sean et al at Tummy have been using.  It is kinda slow, but it 
works great for them.

Verizon and Sprint both use CDMA systems.  They are currently limited to 
14.4k.  Both are supported by Sierra Wireless pcmcia cards, though only 
the older models support Linux.  The rest are akin to winmodems. :( 
However, many of the phone handsets have a serial interface on which the 
phone pretends to be a modem.  This is what I've used, though you could 
hang yourself on all the cables it requires...
Verizon is rolling out a 3G solution (==faster data) right now, and 
Sprint turned theirs on nationwide this last weekend.
Sprint, by the way, gives you a 10-net IP address.  I'm not sure what 
Verizon does.  On Sprint, you are billed based on minutes of use.  Their 
night and weekend plans make hanging out at the coffee shop on a 
Saturday inviting, though...
By the way, the new 3G systems have different billing rules, based on 
bandwidth instead of time.  These are brand new, though, so I haven't 
looked into them.  I'd overheard a number like 2MB a month.  Yeek.

Voicestream->Tmobile has a pure GSM interface, which is kind of neat, 
but I can't say I actually understand it.  Anyway, they provide a packet 
interface, like an ethernet card, instead of a connected interface like 
a modem. They bill by bandwidth, but I am unaware of the rates. 
Somebody else might know a bit more about this one than me.

> Many years back I recall you could buy little PCMCIA cards that could 
> send/receive e-mail messages on a HP100LX palmtop. I believe this was based 
> on CPDP technology. Does this sort of service still exist?

Again, it does, but I believe that CDPD is being somewhat phased out in 
deference to GSM and 3G-CDMA (1xRTT/DO?).  There are cards that support 
these, too, but in my experience, they are Windows-only.

> On a similar note, suppose I have an existing cellular phone (an AT&T prepaid 
> plan). This already has built-in text messaging, but is a pain to use on the 
> cell phone. Is there anyway I could pop a cellular PCMCIA card into a 
> computer and have it send/receive text messages via my existing pre-paid 
> plan?

On Sprint, no.  Your card is considered a separate phone, which you can 
activate with their add-a-phone program.  The GSM systems might be more 
forgiving, since you can swap the SIM card back and forth...
Also,  especially if you are using Verizon service, look into the Yahoo 
Messenger for your messaging -- it has a pretty nice Linux client, and 
is well supported on the Verizon wireless web phones.
Finally, remember that you can send messages to phone using an e-mail 
address.  For instance, tendigitnumber at messaging.sprintpcs.com will send 
a message to a sprint phone...

> Any ideas or links to sites containing information would be appreciated.

Google is, as always, your friend.  However, if you have questions about 
the Sprint system in the area, I'm fairly well versed in it.