Bluetooth and GPRS

[PSLoh]

Hi,

I have an application that connects to the Bluetooth DUN service of my mobile phone. By using the hyperterminal and the windows console application that I have done using C language, I am able to dial out to a fixed line.

However, when I switch to the GPRS mode using +CGDCONT=1,"IP","APN", I will get the NO CARRIER error after I dial *99#. My service provider has verified that the *99# is the correct number to dial.

Please do advice me on how I can proceed.

Thanks and regards,
PS

[Steve Sharp]

I might be a little bit off in my explanations and assumptions here, but my understanding of the way it works is that GPRS is your data connection. When you dial the access number you are establishing your data connection. If I am reading into your purpose correctly, you are wanting to use your phone as a modem to call into an ISP or to a dialup server. If that is the case, you would just dial the number without switching to gprs first.

This is probably a bad example, but consider your gprs connection like an ethernet lan connection at your home or work. If you wanted to use your home computer that is connected to the ethernet, to call an ISP or dialup server, you would need to use a telephone line plugged into the modem port, not try to dial over the ethernet (VOIP excluded). Does that help explain things, or make it all clear as mud.:)

[PSLoh]

Hi Steve,

Thank you for the advice.

I have tried to dial the number provided by my ISP without switching to GPRS first. The number I dial is the generic *99#. I guess that once I make this call, the telephone operator, which is also my ISP, would know that I am trying to connect a dial up.

But after I make the dial by sending ATDT*99#, I get a respond "CONNECT" then some unreadable characters follows for a while. After sometimes, the "NO CARRIER" respond will appear and the unreadable characters stop. Are these characters the PPP packets for a dial up? I am also not prompted to enter any password or login at all.

Are there any thing else that I should change?

Thanks and regards,
PSLoh

[Steve Sharp]

Again, I may be wrong here, but if you are trying to connect to a remote computer using DUN, then you are trying to have your computer use your phone as a dial up modem. I believe that the ATDT*99# is the setting to connect your phone to your GPRS service. Once you connect to GPRS, the only thing the GPRS network is going to understand is an IP address, not a phone number.

I think, if I understand you correctly, that you are tethering your phone to your computer with bluetooth and then attempting to make a call to a DUN host using a phone number (not the ATDT*99#), but a real 7 - 10 digit number.

Tethering is typically where you connect your computer to your phone via usb bluetooth etc, and use the devices data service (GPRS, UTMS, etc) to browse the internet, pull email, etc. You can't dial a number over this service as you are connected to the internet, not the public switched phone network.

Check this post for tethering instructions.

http://forum.xda-developers.com/archive/index.php/t-337714.html

You are actually trying to use your mobile phone as an analog modem, but your phone has no hardware inside it to respond to the answering modem when you call your ISP or remote host via a phone call.

There is a way to do this, but it involves some work. You have to build a small adapter that will convert your mike and earphone connections into a 2 wire that will plug into your computers analog modem. There are problems with this type of data service. It is slow, doesn't support cell changes, and may be disallowed by your carrier. Check this post to see what I am talking about.

http://forum.xda-developers.com/showthread.php?t=361928

Let me know if this sheds any light on the subject, or if I just really don't understand what you are trying to do.

Thanks,

[PSLoh]

Hi Steve,

Thanks for your reply. I always thought that *99# was the number for me to dial up to the ISP but now I guess I have to find out more about it.

I was using the ATcommand: AT+CGDCONT=1,"IP","APN" to set up my phone to use GPRS network and then ATDT*99#. I thought that by issuing these 2 commands to the phone, I would be able to instruct it to connect to my ISP and set up the PPP link between my phone and the laptop.

Do you mean that the number to dial is wrong?

If I were to succeed in dialing to my ISP, are there any things (commands or code) that I need to set up the PPP link on my WinXP laptop?

Thanks and regards,
PSLoh