Nokia 7250 & iPAQ 1940

[KiLLBOi]

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These settings work for both 7250 and 3650
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I just wanted to brag I have finally succeeded in connecting to the net using my 7250 as a gprs access point!

I will be posting instructions on how to connect the two in a few days. I will also be posting instructions for the t68i aswell.

By the I use fido but from what I understand it doesn't matter.

seeya!

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SETTINGS FOR FIDO GPRS INTERNET ACCESS
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Connection name "FIDO Internet"
Modem type "Generic IrDA"
Number to dial "*99#"
Connection Speed "57600"
Username "fido"
Password "fido"
Modem Connection String "+CGDCONT=1,"IP","internet.fido.ca"

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I have recently found out that if you change the
phone number to "*99***1#" these settings will
work with Sony Ericsson phones.

Also, if the Modem Connection String doesn't work
try using this one instead:

"AT+CGDCONT=1,"IP","internet.fido.ca"
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I'll provide step by step instructions later. Enjoy!

[Tenoq]

Clever - very clever. Well done :)

Are you able to set the connection speed any higher? 'cause at 56k, it's not taking full advantage of GPRS, is it? I thought the max speed was around 168kb, for GSM.

[Michael]

I've never even gotten a speed of 56k on a GPRS connection, let alone something greater than 100.

[jquirke]

The maximum speed of GPRS (GMSK) in a particular direction is when fully utilising 8 PDCHs simultaneously, using the CS-4 coding scheme (which uses no convolutional coding, and minimal check sequences). The data rate is 21.4kbps per PDCH in this case, which would result in a max speed of 171.2kbps.

However, this is including the overheads associated with many layers of the GSM system including:

The RLC/MAC(Radio Link Control) - Medium Access Control headers
The LLC (Logical Link control) headers
the SNDCP (Subnetwork Dependent Convergence Protocol) headers
the IP (Internet Protocol) headers
the TCP (Transmission Control Protocol) headers.

That's a lot of header overhead, so obviously, a number of factors is going to reduce the overhead

- maximum number of simultaneous PDCHs in both the network and MS (multislot class). Typical phones offer 3-4 PDCHs (at least in the downlink direction). The Australian networks allow this too.

- coding scheme - the network may switch coding schemes depending on signal conditions

- protocol overhead

- users currently sharing the same PDCH (other mobile phones)

- modulation scheme (see below "EDGE")

Typically with 3 PDCHs on an Aussie network, you can obtain speeds of around 40kbps under reasonable signal conditions, I have personally verified this.

As a side note, a newer form of GPRS, "E-GPRS", or EDGE (Extended Data rates for the GSM Evolution)(not supported in many GPRS phones or networks) uses 8PSK modulation to achieve a lot higher data rates. In the case of MSC-9 (the lowest level of FEC & error check) data rates of 59.2kbps per PDCH can be obtained. Therefore, with 8 PDCHs, the maximum data rate is 473.6kbps (before the RLC/MAC level).

Finally, what's stopping using multiple physical channels (each carrying up to 8 PDCHs)? I've never seen anything in the GSM specifications specifically stating this cannot be done. If this is so, and phones eventually support this (although I would say this is unlikely), we could see insane data rates (in the Mbps) over the GSM/GPRS network.

[Tenoq]

Originally posted by jquirke
Finally, what's stopping using multiple physical channels (each carrying up to 8 PDCHs)? I've never seen anything in the GSM specifications specifically stating this cannot be done. If this is so, and phones eventually support this (although I would say this is unlikely), we could see insane data rates (in the Mbps) over the GSM/GPRS network.

Looks like I was bang on the money then. Do u know what the deal is with CDMA 1x, jquirke? 384kbps, or something, I thought - same underlying principles?

Oh, and as for phones using multiple channels - wouldn't it need to 'login' on a seperate channel? And thus might be restricted to only one channel as each phone number is likely to have only one account? I could be shooting way wide of the mark here - but it seems somewhat logical to me.

I think another restriction again, is the extra work manufacturers would need to put in to make this happen - and I imagine it would need some co-operation from the service providers as well. There would be a limit on the bandwidth a given tower can transmit as well... though I imagine it would be hard to overload it :)

Tho, in an ideal world - that'd be a great idea, jquirke. I could live with 1Mbps on my phone - although I can see my data bill going thru the roof!

[jquirke]

Originally posted by Tenoq
Looks like I was bang on the money then. Do u know what the deal is with CDMA 1x, jquirke? 384kbps, or something, I thought - same underlying principles?

Oh, and as for phones using multiple channels - wouldn't it need to 'login' on a seperate channel? And thus might be restricted to only one channel as each phone number is likely to have only one account? I could be shooting way wide of the mark here - but it seems somewhat logical to me.


The radio interface (known in the industry as the "Um" link, between the phone (MS) and the base station (BTS) ) is generally independent of your MSC/HLR context. This means, the GGSN, SGSN, MSC & HLR (which handles your account) have no knowledge of what the story is with channels, radio link settings, etc between your phone and the base station. They don't care either. All they want to do is route your connections and keep track of where you are in the GSM network.

What the MSC/SGSN sees is just one pipe to your phone, it doesn't understand how the channels are set up, how many channels are in use, etc. This is the responsibility of the BTS & BSC (Base Station Controller).

What normally happens is the phone requests GSM services on the SDCCH/SACCH (which are control channels) and GPRS services on a PDCH. Then, once a low-data rate connection is setup, additional channels are negotiated and assigned as necessary, depending on the phone & network capabilities, and what needs to be done.

This even happens for voice calls, when you first receive of make a call, you'll hear the duh-duh-duh in nearby speakers. This is the phone requesting a voice channel on the SDCCH.

Now, back to GPRS. When we talk about GPRS speeds, we usually quote around 40kbps, because that is the capability of most handsets, which support up to 3 PDCHs (most of the Nokias, for example). However, it is possible for GPRS to achieve much higher speeds, but the phones need to support it and the network needs to allow it.

As for CDMA 1xRTT, I'm not sure on what it's realistic speed is. I don't know the technical details of the CDMA system at a level low enough to be able to verify the claim of 384kbps.

[darkstar]

If anyone needs settings help for PDAs and phones give me a shout in PM and i'll get you step by step instructions.

(I work for Orange UK and we have settings guides for all of our phones, adaptable to most other GSM models.)

[Tonik]

Hi, does anyone know how to set up a gprs connection between a Nokia 6280 and a iPAQ 1940. I have established a bluetooth connection after downloading a security patch from HP and I have all the GPRS/WAP/MMS settings in my phone and the are ok. I have put the extra string command in for an o2 access point (thats my network). When i open pocket ie it starts the bluetooth connection ok and creates a GPRS link with no problems however an internet link does not seem to be established - can anyone help?