Test the AT commands with the modem first, without the
telephone.
Run HyperTerminal. Then type in the AT commands, and the
modem and server reponses will display on the terminal
(you may need to disconnect the modem to phone cable to
hand up if you hang a communication in the middle).
The AT commands vary from modem to modem, so you may need
to check the manual for your modem. In general ATI gives
you information (mine displays maximum speed); ATI1,
ATI2, and so on shows additional information (e.g. modem
brand); ATZ resets modem...
After gathering information about the modem (e.g. the AT
manual for your modem), try entering the commands the
phone is supposed to send to the modem, and inspect the
answer.
Common problems sometimes include sending AT commands too
earlier which are lost or mangled (e.g. sending commands
to the server while the phone is still dialing; the AT
commands provide for time delays like the + comma, and so
on to avoid this)
>-----Original Message-----
>Dear anyone who can help me out,
>
>I'm currently having problem with internet connectivity
bandwidth
>
>
>The situation is:
>---------------------------------------------------------
-----
>I have a Nokia 3105 CDMA mobile phone which is capable
of 153,600 bps
>The phone has an external serial port (Nokia called it
called PopPort)
>The phone serial port can be connected to PC via a
Serial-to-USB data cable
>which has bandwidth of 230,400 bps
>
>
>To connect to the internet it has to dial to a server
dial up number which
>is Public Switched Telephone Network(PSTN) not Packet
Data Network (PDN)
>which has a advertised bandwidth of 57,600 bps
>
>
>To connect to a PSTN, the phone modem requires an AT
command as follows in
>INF/registry:
>AT+CRM=0
>
>
>Diagnostic clue so far:
>---------------------------------------------------------
-----
>And it connects to the network with an unverified speed
>Windows simply just report it as 230,400bps or any
number (as I defined at
>modem maximum Serial to USB speed property page in
control panel)
>
>
>In windows dial up modem log, modem reports:
> connect numeric response result code is:
> 15
> (comment : driver has no result code 15 meaning
association)
> verbose response result verb are:
> <cr><lf><cr><lf>CONNECT<cr><cr><lf>
> <cr><lf><cr><lf>CONNECT<cr><lf>
> (comment: no DCE connect speed, compression nor
error control)
> (comment: ATX0 to ATX4 commands doesn't show DCE
connect speed)
> (comment: ATX5 produces modem error)
>
>
>but the problem is the bandwidth is about 1,000bps to
1,800bps at most
>That's much slower than a standard PCI modem dial-up
connection to the same
>network-which is 24,000bps at least to 54,000bps at most
>
>
>For Your Information:
>---------------------------------------------------------
-----
>And BTW I have the latest driver update for both the
phone and data cable
>The phone works just fine and undamaged
>So far, I suspect the data cable works just fine!
>When dialling to premium PDN network and produces about
12,000-18,000bps
>(instead of advertised 153,600bps by Nokia)
>
>
>I have so much question about this phone modem device,
but this is the most
>bottom line problem to solve, anyone with experience or
expertise in modem
>querying or network dial up connection negotiation
please help me.
>
>
>I've been investigating this problem, trying to search
and read so much
>documentation about AT commands so many days(about a
full month?? perhaps)
>I've tried a lot of combination of AT commands to get
the device to connect
>at better speed but the result is nothing
>I have asked Nokia Australia for help, and they just
neglect me
>Please HELP me!
>
>
>Question and Solution Requested:
>---------------------------------------------------------
-----
>How to increase the bandwidth of this type of connection
bandwidth to PSTN?
>well at least at 24,000 to 54,000bps
>
>
>
>
>.
>
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