"Alan" said:
How would I connect a PC to the cellular network to receive the
picture? Thx, Alan
This example from the Cingular web page, was an email gateway to
the cellphones. You need a connection to the Internet, to connect
your PC to an email server. The email gateway at Cingular sends
email messages to the email server. You get a bill at the end of
the month, from your ISP, for connecting to the Internet. You
get a bill from Cingular, for the email gateway and maybe the
SMS/MMS messages.
(Internet) (Internet)
| |
v v
Cingular --- email --------- your--------- dialup modem,
/ \ gateway email or ADSL modem,
/ \ (at server or cable modem
Cell Cel| Cingular) (at the |
User User ISP) |
1 ... N Your PC
(pictures arrive
as email)
The other method, is suggested in this thread. This would be
an option for a computer owner not currently connected to the
Internet. You would get dialup modem performance this way, slower
than using ADSL or cable, in terms of the connection your PC is
getting. But, in this example, the PC is a peer to the other
cell phones. Another cell phone user sees your PC as if it was
a cell phone, so that user addresses you with a phone number,
instead of using that Cingular email address. (For the application
you have in mind, this peer to peer relationship buys you nothing.
Using a GSM/GPRS modem would be slower than using ADSL or a
cable modem.)
http://www.nowsms.com/framer.htm?http://www.nowsms.com/discus/messages/132/291.html
Cingular --- Siemens MC35 external GSM/GPRS modem
/ \ (or Sierra Wireless Aircard |
/ \ 750 PC Card) |
Cell Cel| Your PC
User User
1 ... N
The Siemens device carries the modem analogy a little too far,
by using an actual RS-232 port to connect to your computer.
Thus, it looks exactly like hooking a dial up modem to the
computer. It even supports the "AT" command set, which is the
same interface a modem uses. (Apparently, some cell phones also
allow this modem style operation as well, and the interconnect
could be USB, IR, or Bluetooth to get to the computer. Look
in the user manual, to see if a cell phone you own, supports the
AT command set on one of its interfaces)
http://www.siemens.com/Daten/siecom.../English/file/binary/SB_MC35T_engl_191201.pdf
(apparently, this model is discontinued)
http://www.sierrawireless.com/SupportDownload/SupportDownloadDocumentation/ac750-cw.asp
The best thing to do, if building the second model above, is
to contact your potential cellphone provider. For example,
on the Cingular site, I can find this manual, which talks
about the two products they support. They are using the
SierraWireless 775 PC Card for example, to connect a laptop
to the network. The 775 can function in at least two modes,
either in GSM mode (like a cell phone would) or in WiFi mode
(like wireless networking). You would have to be within range
of a WiFi device, to connect the WiFi way.
http://www.cingular.com/laptopconnect/pdf/modem_wifi_user_guide.pdf
If you talk to the various providers in your area, they will
likely have products for hooking you up to their network.
You can find out which one has coverage in your area, best
rates, rental or purchase hardware, and so on. Make sure you
describe in detail what you want to do, and how sophisticated
the user's phones at the other end of this problem are.
One thing I'm not finding a lot of documentation on, is the
software that runs on the PC. I'd want to see what kind of
interface they offer for sending images and so on. In my
first posting, I jokingly invented a simple protocol for
your users to "pull" messages from the server. In what
I've read so far, this GSM technology is a "push" technology.
A user will not be able to use SMS to "pull" stuff from
your computer. They would have to "push" a text message to
you, requesting data, and your computer "pushes" back an
image. If, on the other hand, your users have WAP/GPRS
(wireless applications protocol, like Internet data) on their
cellphone, then they could deal with your computer as if it
was a web site, they could use http:// and that effectively
allows them to "pull" content from you. In the case of WAP,
you don't have to invent a protocol to implement the service
you have in mind. (But sending data over the cell phone is
another level of service those users would need on their
phones. Not all phones have an Internet interface and web
browser built into the phone.)
Now, I'll draw a picture of what it looks like if your
users can surf the Internet from their phones. Say they
all have that WAP/GPRS (GPRS = general packet radio service).
What you need at your end, is to set up a web site. That
would allow them to "browse" your image collection. If their
web phone supported the FTP protocol, they might even be
able to submit their images to your website as well. You'll
have to read up on WML I expect, to see how a user can send
you stuff.
http://www.cingular.com/mmode/mmode_faq
Cingular ------ Internet ----------- ADSL modem or
/ \ Cable modem
/ \ |
Web Web Your PC
Browser Browser (runs a WML
Phone ... Phone web server)
1 N
If not all the users have sophisticated phones, then you
have to set up a method that satisfies both types of users.
Which means you might still need that email gateway, as
a means of dealing with the users that can only "push"
data.
Looking at the manuals and web sites I've seen so far, it
does look like they tried to make this stuff easy, but I find
they left a lot of the details out. Hope you have better luck
figuring it out than I did
Paul
