Using standard handset as terminal device

Archived from groups: alt.cellular.gsm (More info?)

Hi, folks--

I'd like to set up one of our servers here to monitor our computer networks
and send short text messages to one or more of our techs' cell phones in
case of problems. Seems like the "right" way to do this is with a terminal
module-- I was recommended the Siemens MC35i, but this is Telcel land
(Mexico) where I can pick up a basic GSM handset pretty easily, but they
don't have a clue about dedicated terminal devices. Handset models I'm
looking at are Siemens A56 and A55, and Nokia 1100,3100,3595,6100; anybody
know whether it is feasible to hook one of these up via RS232 to a computer
and control it to send text messages?

Also, if I get a handset to play with and manage to obtain a terminal
module, can I just put the SIM card from the handset into it and have it
assume the personality of that phone? Sorry about my ignorance on how these
things work, I'm new to the GSM world...

Thanks-- Larry
Centro de Investigaciones Biologicas del Noroeste,
La Paz, Mexico
17 answers Last reply
More about using standard handset terminal device
  1. Archived from groups: alt.cellular.gsm (More info?)

    Any handset would work, as long as it's got a built-in modem module. Most
    of older GSM handsets do, many newer models don't. Check the phoine's
    manual to find out.

    You would be better off using a USB cable if it's a Windows computer. Find
    the variety that charges the handset's battery. On a Comport cable you may
    have to do some soldering to connect the charger.

    Modules are better for high-volume traffic, otherwise the handset's just
    fine.

    Yes you can place the simcard into a module or another handset and it would
    work, provided that the new device isn't locked to a carrier other than
    yours


    > Hi, folks--
    >
    > I'd like to set up one of our servers here to monitor our computer
    networks
    > and send short text messages to one or more of our techs' cell phones in
    > case of problems. Seems like the "right" way to do this is with a
    terminal
    > module-- I was recommended the Siemens MC35i, but this is Telcel land
    > (Mexico) where I can pick up a basic GSM handset pretty easily, but they
    > don't have a clue about dedicated terminal devices. Handset models I'm
    > looking at are Siemens A56 and A55, and Nokia 1100,3100,3595,6100; anybody
    > know whether it is feasible to hook one of these up via RS232 to a
    computer
    > and control it to send text messages?
    >
    > Also, if I get a handset to play with and manage to obtain a terminal
    > module, can I just put the SIM card from the handset into it and have it
    > assume the personality of that phone? Sorry about my ignorance on how
    these
    > things work, I'm new to the GSM world...
    >
    > Thanks-- Larry
    > Centro de Investigaciones Biologicas del Noroeste,
    > La Paz, Mexico
  2. Archived from groups: alt.cellular.gsm (More info?)

    And a little-known fact: many GSM networks block text messages cycling to
    the same number. You may not be able to send more than 10 to 12 messages in
    a row to the same number. It the spacing between messages is 10 to 20
    minutes, or you use several receipient numbers it would work just fine.


    > Hi, folks--
    >
    > I'd like to set up one of our servers here to monitor our computer
    networks
    > and send short text messages to one or more of our techs' cell phones in
    > case of problems. Seems like the "right" way to do this is with a
    terminal
    > module-- I was recommended the Siemens MC35i, but this is Telcel land
    > (Mexico) where I can pick up a basic GSM handset pretty easily, but they
    > don't have a clue about dedicated terminal devices. Handset models I'm
    > looking at are Siemens A56 and A55, and Nokia 1100,3100,3595,6100; anybody
    > know whether it is feasible to hook one of these up via RS232 to a
    computer
    > and control it to send text messages?
    >
    > Also, if I get a handset to play with and manage to obtain a terminal
    > module, can I just put the SIM card from the handset into it and have it
    > assume the personality of that phone? Sorry about my ignorance on how
    these
    > things work, I'm new to the GSM world...
    >
    > Thanks-- Larry
    > Centro de Investigaciones Biologicas del Noroeste,
    > La Paz, Mexico
  3. Archived from groups: alt.cellular.gsm (More info?)

    "Larry Miller" wrote:

    > Hi, folks--
    >
    > I'd like to set up one of our servers here to monitor our
    > computer networks and send short text messages to one or more
    > of our techs' cell phones in
    > case of problems. Seems like the "right" way to do this is
    > with a terminal module-- I was recommended the Siemens MC35i,
    > but this is Telcel land (Mexico) where I can pick up a basic
    > GSM handset pretty easily, but they
    > don't have a clue about dedicated terminal devices. Handset
    > models I'm looking at are Siemens A56 and A55, and Nokia
    > 1100,3100,3595,6100; anybody know whether it is feasible to
    > hook one of these up via RS232 to a computer and control it to
    > send text messages?

    I don't know about those particular Nokias or the Siemens A56,
    but the A55 doesn't have an inbuilt "modem" capable of sending
    SMSs via the serial port. However, an A55 can be
    firmware-upgraded to a C55 (which does have the modem) using a
    procedure sometimes described on newsgroups.

    The cheapest handsets tend not to have inbuilt modems.

    You should also note that there are 2 common modes for the
    interaction between GSM device and computer when messaging over
    a serial connection: text-mode and PDU-mode.

    Text-mode allows you to send clear text across the serial
    connection, whereas PDU-mode requires encoding/decoding at the
    PC end. "hello" in text-mode is "E8329BFD06" in PDU-mode, so
    you'd need to incorporate the conversion algorithms in your
    software for a PDU-mode device. Text-mode GSM devices do the
    conversion internally.

    Siemens handsets are PDU-mode-only devices, but their terminals
    support both modes.

    Ashot's point about providing power may be an important factor
    in favour of using a terminal instead of a handset. Depending
    on the fine details of the charge-termination algorithm, a
    handset battery on constant charge may have a very short life
    indeed.

    > Also, if I get a handset to play with and manage to obtain a
    > terminal module, can I just put the SIM card from the handset
    > into it and have it
    > assume the personality of that phone? Sorry about my
    > ignorance on how these things work, I'm new to the GSM
    > world...

    In that direction, yes, but a locked handset may not accept
    another SIM.

    John
  4. Archived from groups: alt.cellular.gsm (More info?)

    "Ashot Shahbazian" <tyrebusters(at)covad(dot)net> wrote in
    news:4950d$4113d32b$40694c09$24995@msgid.meganewsservers.com:

    > Any handset would work, as long as it's got a built-in modem module.
    > Most of older GSM handsets do, many newer models don't. Check the
    > phoine's manual to find out.

    Thanks. I'm confused. Is a modem used for SMS messages? I thought that
    was some digital protocal between the phones. Or is it that the modem is
    required for the PC to phone communications?

    > You would be better off using a USB cable if it's a Windows computer.

    Nah, we work in Unix here for the server side stuff. Good point on the
    battery and charging issues, hadn't considered that.

    > Yes you can place the simcard into a module or another handset and it
    > would work, provided that the new device isn't locked to a carrier
    > other than yours

    Good news, thanks!

    --Larry
  5. Archived from groups: alt.cellular.gsm (More info?)

    "Ashot Shahbazian" <tyrebusters(at)covad(dot)net> wrote in
    news:54c$4113d40a$40694c09$25280@msgid.meganewsservers.com:

    > And a little-known fact: many GSM networks block text messages cycling
    > to the same number. You may not be able to send more than 10 to 12
    > messages in a row to the same number. It the spacing between messages
    > is 10 to 20 minutes, or you use several receipient numbers it would
    > work just fine.

    Sounds like a useful mechanism to prevent abuse, but I kinda doubt Telcel is
    that enlightened. :>

    --Larry
  6. Archived from groups: alt.cellular.gsm (More info?)

    John Henderson <jhenRemoveThis@talk21.com> wrote in news:2ni9qmF182s2U1@uni-
    berlin.de:

    > You should also note that there are 2 common modes for the
    > interaction between GSM device and computer when messaging over
    > a serial connection: text-mode and PDU-mode.
    >
    > Text-mode allows you to send clear text across the serial
    > connection, whereas PDU-mode requires encoding/decoding at the
    > PC end. "hello" in text-mode is "E8329BFD06" in PDU-mode, so
    > you'd need to incorporate the conversion algorithms in your
    > software for a PDU-mode device.

    Good to know, but no problem as long as we have the specs.

    > Siemens handsets are PDU-mode-only devices, but their terminals
    > support both modes.

    Thanks. After reading y'alls comments I'm even more convinced that a
    terminal is the way to go, but have a bit of a supply problem here in
    Mexico. Anybody know of dealers for (preferably) Siemens terminals in the
    southern U.S.A. or Mexico?

    >> Also, if I get a handset to play with and manage to obtain a
    >> terminal module, can I just put the SIM card from the handset
    >> into it and have it
    >> assume the personality of that phone? Sorry about my
    >> ignorance on how these things work, I'm new to the GSM world...
    >
    > In that direction, yes, but a locked handset may not accept
    > another SIM.

    Not much worried about that. The packages that Telcel sells pretty much
    give away the handset and I'd just consider it a disposable carrier for the
    SIM which would be destined for the terminal module. :>

    Now the question is where to get a terminal module here in the Americas.
    Seems like Siemens has much better represantation the other side of the
    pond...

    Thanks-- Larry
  7. Archived from groups: alt.cellular.gsm (More info?)

    "Larry Miller" wrote:

    > Thanks. I'm confused. Is a modem used for SMS messages? I
    > thought that was some digital protocal between the phones.
    > Or is it that the modem is required for the PC to phone
    > communications?

    "Modem" is something of a misnomer in the context of a GSM
    device. It's more like a general purpose command interpreter
    for the "AT+C" cellular extensions to the standard "AT" command
    set. Usual functions include establishing data calls (ISDN or
    "analog"), messaging (2-way SMS and the reception of cell
    broadcasts), and perhaps GPRS connectivity.

    John
  8. Archived from groups: alt.cellular.gsm (More info?)

    "Larry Miller" wrote:

    > ... no problem as long as we have the specs.

    They are available as PDF files (download free after
    registering) from www.etsi.org. I'd suggest starting with GSM
    specs 07.07, 07.05, 03.38 and 03.40. Go to the download area
    (Services & Products), search for each by number, and download
    a recent version from the unsorted list.

    > Thanks. After reading y'alls comments I'm even more convinced
    > that a terminal is the way to go, but have a bit of a supply
    > problem here in Mexico. Anybody know of dealers for
    > (preferably) Siemens terminals in the southern U.S.A. or
    > Mexico?

    Try http://tinyurl.com/4p7jh.

    John
  9. Archived from groups: alt.cellular.gsm (More info?)

    John Henderson <jhenRemoveThis@talk21.com> wrote in news:2nsr69F42eq1U1@uni-
    berlin.de:

    > "Larry Miller" wrote:
    >
    >> Thanks. I'm confused. Is a modem used for SMS messages? I
    >> thought that was some digital protocal between the phones.
    >> Or is it that the modem is required for the PC to phone
    >> communications?
    >
    > "Modem" is something of a misnomer in the context of a GSM
    > device. It's more like a general purpose command interpreter
    > for the "AT+C" cellular extensions to the standard "AT" command
    > set.

    Ah, very clear-- thanks. Is that a standard command set for the extensions?

    --Larry
  10. Archived from groups: alt.cellular.gsm (More info?)

    John Henderson <jhenRemoveThis@talk21.com> wrote in news:2nss22F4epc7U1@uni-
    berlin.de:

    >> ... no problem as long as we have the specs.
    >
    > They are available as PDF files (download free after
    > registering) from www.etsi.org. I'd suggest starting with GSM
    > specs 07.07, 07.05, 03.38 and 03.40.

    Oooh, what a wealth of information. :>

    >> Thanks. After reading y'alls comments I'm even more convinced
    >> that a terminal is the way to go, but have a bit of a supply
    >> problem here in Mexico. Anybody know of dealers for
    >> (preferably) Siemens terminals in the southern U.S.A. or
    >> Mexico?
    >
    > Try http://tinyurl.com/4p7jh

    Very nice. :>

    Thanks a bunch-- Larry
  11. Archived from groups: alt.cellular.gsm (More info?)

    John Henderson <jhenRemoveThis@talk21.com> wrote in news:2nss22F4epc7U1@uni-
    berlin.de:

    > "Larry Miller" wrote:
    >
    >> ... no problem as long as we have the specs.
    >
    > They are available as PDF files (download free after
    > registering) from www.etsi.org.

    A wealth of information. :>

    Anybody know of dealers for

    >> (preferably) Siemens terminals in the southern U.S.A. or
    >> Mexico?
    >
    > Try http://tinyurl.com/4p7jh.

    Very nice. Mmmm, now why didn't I find that? :>

    Thanks a bunch-- Larry
  12. Archived from groups: alt.cellular.gsm (More info?)

    "Larry Miller" wrote:

    > Ah, very clear-- thanks. Is that a standard command set for
    > the extensions?

    In general - yes. Implementations of AT+C commands are standard
    across manufacturers, but I need to qualify that immediately.

    Many individual commands are optional, or mandatory only if
    certain other optional commands are implemented. And the spec
    for some commands gets interpreted slightly differently by
    different manufacturers occasionally. An example might be
    where a null value for a parameter means "all possible values"
    to one manufacturer, and "no values" (disable the feature) to
    another.

    GSM 07.07 has a very useful section on the syntax of AT+C
    commands, and details the means by which you can query the
    device's implementation, and permissible range of values.

    Manufactures often add their own proprietary commands, using a
    different command prefix. Siemens-specific commands begin
    "AT^S" instead of "AT+C".

    John
  13. Archived from groups: alt.cellular.gsm (More info?)

    "Larry Miller" wrote:

    > Thanks. After reading y'alls comments I'm even more convinced
    > that a terminal is the way to go, but have a bit of a supply
    > problem here in Mexico. Anybody know of dealers for
    > (preferably) Siemens terminals in the southern U.S.A. or
    > Mexico?

    You might want to consider Wavecom GSM terminals:
    http://www.wavecom.com/home/XMLindex.php.

    They seem to better regarded than Siemens, since Siemens
    reputedly outsourced firmware development. If I was buying one
    today, I'd go for the Wavecom (although I haven't used one).

    John
  14. Archived from groups: alt.cellular.gsm (More info?)

    John Henderson <jhenRemoveThis@talk21.com> wrote in news:2nvg4qF582soU1@uni-
    berlin.de:

    > You might want to consider Wavecom GSM terminals:
    > http://www.wavecom.com/home/XMLindex.php.
    >
    > They seem to better regarded than Siemens, since Siemens
    > reputedly outsourced firmware development. If I was buying one
    > today, I'd go for the Wavecom (although I haven't used one).

    *Very* interesting. And they have a branch in San Diego. :>

    Thanks for the info! I'll contact those folks.

    --Larry
  15. Archived from groups: alt.cellular.gsm (More info?)

    "Larry Miller" wrote:

    > *Very* interesting. And they have a branch in San Diego. :>
    >
    > Thanks for the info! I'll contact those folks.

    I've decided I'll probably buy a Wavecom unit myself soon
    (Fastrack 1206). Looking at the specs though, I'm not sure
    that Wavecom offer much for the 1900 mHz band used in
    Mexico/USA.

    John
  16. Archived from groups: alt.cellular.gsm (More info?)

    John Henderson <jhenRemoveThis@talk21.com> wrote in news:2o28qqF67hi5U1@uni-
    berlin.de:

    > "Larry Miller" wrote:
    >
    >> *Very* interesting. And they have a branch in San Diego. :>
    >>
    >> Thanks for the info! I'll contact those folks.
    >
    > I've decided I'll probably buy a Wavecom unit myself soon
    > (Fastrack 1206). Looking at the specs though, I'm not sure
    > that Wavecom offer much for the 1900 mHz band used in
    > Mexico/USA.

    Well, I'm glad you mentioned that-- I'm very embarrassed to say I missed the
    frequency detail and was looking at the 1206 myself, which would have
    obviously been a problem. :-\

    They do have the Q2426 module which runs 850/1900 mhz.

    From what I can see, nor does Siemens offer a 1900 mhz terminal though they
    have several tri-band modules which can be integrated. Mmmf, that adds a
    level of complexity that I hadn't anticipated.

    Wonder why these folks aren't (don't appear to be) offering 1900 terminals.
    Seems like a useful niche...

    Thanks-- Larry
  17. Archived from groups: alt.cellular.gsm (More info?)

    John Henderson <jhenRemoveThis@talk21.com> wrote in news:2o28qqF67hi5U1@uni-
    berlin.de:

    > "Larry Miller" wrote:
    >
    >> *Very* interesting. And they have a branch in San Diego. :>
    >>
    >> Thanks for the info! I'll contact those folks.
    >
    > I've decided I'll probably buy a Wavecom unit myself soon
    > (Fastrack 1206). Looking at the specs though, I'm not sure
    > that Wavecom offer much for the 1900 mHz band used in
    > Mexico/USA.

    I've just been informed by the Brazilian Wavecom distributor that Multitech
    is producing a 1900 mhz terminal using the Wavecom hardware. Following that
    lead now... :-}

    Thanks-- Larry
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