This page was created out of frustration for the lack of information available to successfully connect to the internet with a computer, mobile phone, GPRS and bluetooth. So I decided to document te process - maybe this will help you.
Text copied from http://www.sybu.co.za/info_gprs_bluetooth.php

Here's how I got it to work - using only the standard stuff of Windows XP, I did not use IVT Blue Soleil or any other 3rd party drivers or software. This info is for Windows XP only. Bluetooth drivers on my system - XP Service Pack2 (SP2) build 2180.

I've tested this successfully on the following mobile phones : Nokia 6820, 6230, 9300, 6680; Sony Ericsson K750i, Samsung D500, I-Mate Sp5 and on the following cellular networks : South Africa - Vodacom, Cell-C, MTN, Virgin Mobile, United States - Cingular, United Kingdom - Vodafone

I've received feedback from people that successfully connected after reading this document, with Siemens S65, Nokia 6510, Nokia 6233, 6300, 6600, 6680, 6234, 6822, N70, N95, N-Gauge, Samsung D600, SGH-E880, Z400, E250, Motorola v550, v300, v360, Razr v3i, Sony Ericsson K700i, K750i, Motorola 16, V3x, LG M4410, NEC 616, QTek 8310, HP 6515....
On networks T-Mobile in USA, T-Mobile in Croatia, T-Mobile in UK, Vodafone in UK, Vodafone in Italy, Airtel, BSNL, Vodafone in India, Maxis in Malaysia, Orange in Slovakia, DNA in Finland, MTN Nigeria, Orange Caraibe in Guadeloupe, Mobistart in Belgium, MCel in Mozambique, MTC in Namibia, Telekom in Serbia, Orange in Poland, Orange in Spain, Etisalat in UAE ...

Some info before I get started: There are basically 2 ways to get this working:

1. Configure the mobile phone's internet settings correctly, and then just instruct the DUN of windows to use a specific internet profile of the phone. (Part 1,2,3,4)
2. Ignore the internet profiles of the phone and configure the DUN of windows to send additional modem initialization for connection. (Part 1,2,6,4)

This document deals mostly with approach 1, since in my opinion this is preferred as this will then also allow you to use the phone for web browsing, as it's internet settings will then be correct. However, in some cases you may be forced to use method 2 (as for the Samsung D500).

Part 1: Setup of Bluetooth, Mobile phone setup
Part 2: Check if the Bluetooth Modem link has been configured.
Part 3: Setup op GPRS on the mobile phone
Part 4: Setup of Dial-up Networking (DUN)
Part 5: Connection issues
Part 6: Manual setup of the GPRS initialization.
Manual setup of a cellphone serial modem link via bluetooth

Part 1 : Setup of Bluetooth, Mobile phone setup

On laptop. Plugin bluetooth dongle into USB port, if it's the 1st time you're doing this, wait while Windows installs the device.

On you phone: Enable Bluetooth on your phone, and keep it switched on for the duration of the setup.
On Nokia 6820 -> Menu -> Settings -> Connectivity -> Bluetooth -> Bluetooth On

On Laptop. Add a new bluetooth device (your mobile phone)
On Control Panel -> Bluetooth Devices- > Add ->

Select 'My device is set up..' and press next to search for device

If the phone was found after searching for it, the following is displayed...

Note: If you receive the following message...

Check the following:
1- If the phone is switched on and that the bluetooth is enabled.
Check for the ((º)) symbol on the display of the mobile phone. This shows the bluetooth is on.
2- If you are sure that the bluetooth is enabled on the phone, ensure that you have disabled any other 3rd party Bluetooth software - if it was installed as it may conflict with the standard drivers on the system.

Following the next step, after successful detection of the mobile phone, you will be prompted which passkey mechanism to use, select 'Let me choose, my own...' and enter a passkey. In this example I use 0000

After the next step, the phone should now display...

The Nokia will now display...

Pair with?
<Computer Name>

Press Accept on the phone.

The phone will now display that you should enter the passkey, type in the key that you have selected, for my example it was 0000.

The phone will now display:

Connect with?
<Computer Name>

Press Accept on phone.

You'll now see some messages displayed on the tasktray (next to clock as the device is installed)

During the installation new COM ports will be added to Windows which are associated with Bluetooth and the communication with the phone. It is important to make a note of the 'Outgoing COM port' as you will have to select it at a later stage.
In this example we make a note of COM port 3 as we need to select it during the DUN setup.

Back at the Bluetooth devices form, the display will now show the phone and that the passkey is enabled.

Part 2: Check if the Bluetooth Modem link has been configured.

On XP -> Control panel -> click the 'Phone and Modem Options'->Modems Tab

Notice that a Modem has been installed over the Bluetooth link, the attached com port may differ for your system.

If the bluetooth link is not shown :
- cancel the dialog, ensure that bluetooth is enabled on your phone, then return to this dialog.
- if is still does not display then you have a few options :
option 1. manually add a modem connection. Click for how to manually add a cellphone serial modem link via bluetooth.
option 2. install the Bluetooth modem drivers for the Bluetooth dongle that you received with the dongle.
option 3. get another Bluetooth dongle that is natively supported by Windows XP and does not require additional driver installation.

You can test if the modem enables the phone, by selecting Properties->then the 'diagnostics tab' then 'Query Modem'

This should result in the laptop attempting to query the modem, which now is the mobile phone, the phone will display a message

Connect with?
<computer name>

Part 3: Setup op GPRS on the mobile phone
You must either setup the GPRS settings on the phone -OR- perform a manual setup for the modem as explained in Part 6 .

Part 3a: Setup op GPRS on the mobile phone. - Nokia

The next step is to setup and enable GPRS on the mobile phone. These instructions are for the Nokia 6820, 6230, but the menu items will be similar for other models.
On Menu-> Settings -> Connectivity -> GPRS -> GPRS connection -> select 'Always Online' (You can always change this to 'When needed' once everything is working

On Menu-> Settings -> Connectivity -> GPRS -> GPRS modem settings
select option 'Edit active access point'

now select 'Alias for access point'

type in a name, this is just a descriptive name and can be anything, but it may be useful to name it so that you know to which network it belongs

now select 'GPRS access point'

Enter the name for the GPRS access point, this you must get from your network provider.

For South Africa, network Vodacom it is: internet
For South Africa, network CELL-C it is: internet
For South Africa, network MTN it is: internet
For South Africa, network Virgin Mobile it is: vdata

It will be something else for your network! It may also be in IP format such as 193.113.200.200

You are done with the setup. On the phone display you'll now see the G symbol, indicating that the GPRS is enabled.

Part 3b: Setup op GPRS on the mobile phone. -Sony Ericsson K750i

For Sony Ericsson K750i the GPRS access point can be configured :
Menu->settings->tab connectivity->internet settings->internet profiles->
edit or create a new profile. If you are creating a new profile, follow the settings below when asked which data account to use.

When asked for "Connect Using", create a new data account:

Connect Using -> New Account -> GPRS data -> Enter an accounts name such as WAP GPRS

The screen should show "New GPRS data". Enter the following values for the settings:

APN: internet
Username:
Password:
Login request: Off
Allow calls: Automatic
IP address: ... [Leave blank]
DNS address: ... [Leave blank]
Authentication: Select only PAP
Data compression: Off
Header compr.: Off

Now press the "Save" button. The screen will show the message "New GPRS account created". Scroll down to the profile you have created and press the "More" button and then select "Settings". Confirm that you have the following values set:
Connect using: [the data account you created above]
Internet Mode: WAP
Gateway Address: For South Africa, Cell-C this is [196.031.116.250]
Security: Off
Username:
Password:

Press the "Save" button. Scroll to the profile you have just created and press the "Select" button. The display will show "New profile created".

Part 4: Setup of Dial-up Networking (DUN)

On Xp , in the Control panel -> select 'Network Connections', then select 'Create a new connection'

Select to use a dial-up modem.

Now only select a single option - the Bluetooth link on the COM port that was installed earlier, in this example it is COM 3, but it may well be different to your computer.

If the link is NOT shown then Click for how to manually add a cellphone serial modem link via bluetooth.

Now enter a name for the dialup

For the phone number use *99#
NOTE: This will instruct the phone to use the default or 1st GPRS profile on your phone. If you have multiple profiles GPRS profiles on your phone and you do not want to use the default profile, the change the phone number to *99*n# and replace the n with number 1-9 of the profile you want to use.

Then leave the username, password empty!
Decide if you want to make this the default connection or not.

Finally decide if you want to make icon on desktop fro this connection

You are now ready to attempt an internet connection!

Once again leave the username and password empty and press dial.

The mobile phone will display
'Connect with?'
<computer name>

Accept this

and on XP, you'll see

If all is well you see the following

Also notice on the mobile phone that the GPRS symbol has changed to G in a frame- this means it's connected!

You are now ready to surf the internet and download email etc.

Part 5: Connection issues

If you get the message 'Subscribe to GPRS first' the following may be wrong.

1. Most likely cause : the GPRS access point is incorrect. Contact your service provider to get the correct name for your network.

2. What I've noticed is that if you are roaming abroad and not using your home network, you may have to supply a username and password for the dial-up connection for the network you are using. Once again contact the network provider for this.

Part 5b: Connected, but cannot access websites. Error such as "The page cannot be displayed"

The dialer shows that a connection has been established, but when you try to access a website the page error "The page cannot be displayed" is shown. This ma ybe a DNS error, the connection cannot locate the Dynamic Name Server. After extensive testing, the following was established:
-this problem was only on a XP system with Service pack 2 build 2149
-supplying a correct DNS address in the IP setup of the dialup network connection, did not resolve the issue.
- a workaround was to supply a manual GPRS connection string for the modem.
- installing the latest service pack did resolve the issue.

Part 5c: Dials, send login information, but fails on registering on network
- you probably have multiple GPRS accounts configured on the phone, and the DUN is using the incorrect one. Several solutions to this: On the phone swap the GPRS accounts, such that the one that can connect is first, or change the DUN dialer to include the number of the GPRS connection you wish to use. If you have a phone that the default access point can be set, check that the name of the access point is correct.

Part 6 : Manual setup of the GPRS initialization.

As indicated earlier, if you experience connection issues, another approach is to force the mobile phone to use a specific GPRS connection. This will override any setup of the GPRS settings on the phone itself.

On XP -> Control panel -> click the 'Phone and Modem Options'-> Modem Tab ->Modem Link -> Properties -> Advanced Tab

Select the Bluetooth modem link and press 'Properties' button. Then on the Advanced Tab of the dialog that is shown, locate the input ''Extra initialization commands".
Enter the following text and press OK
+CGDCONT=1,"IP","internet"

For Virgin Mobile (South Africa) supply the additional parameters
+CGDCONT=1,"IP","vdata","",0,0

Note that the name "internet" may be different to your network, although this is used by most providers, you may have to change it. The 1 denotes GPRS account number that will be modified. Most Nokia phone support several GPRS accounts.
NOTE: This setting may actually override your GPRS settings for the specific account on the phone.

Click OK, and close the dialogs, then attempt the DUN again. For this example Start Bar-> Connect To->Nokia 6820.

Rate this document... (it may inspire me to edit or add more content. Also if you used a network or phone not listed, it will be useful to know, as it may help others)

If you want to let me know which phone or network you used, rate the document and a feedback form will appear.

All text by André Roodt - 2008