Supreme 20 as a stand-alone GSM modem


#1

I am using a Fastrack Supreme 20 as a USB connected, stand-alone GSM modem to my ISP for browsing, email, etc.
Although everything appears to be working Ok, I do not get the data throughput that I would have expected for EDGE/HSDPA, etc.
I seem to be only getting an approx. maximum of 13kB download throughput. This far slower than using my mobile phone as a modem connected via Bluetooth.
I am located within a 3G area, Is there something that needs to be enabled/configured on the Fastrack to allow/force it use 3G or is it automatic and controlled by the network.


#2

Doess the Fastrack Supreme claim to be an EDGE/HSDPA device…?

wavecom.com/modules/movie/sc … ck_Supreme


#3

Ok, it does not claim HSDPA but the brochure does claim EDGE for the Supreme 20
ie,
Cellular Radio Supporting quad band EDGE
Cellular Data GSM standard, SMS, CSD, GPRS cl10 , EDGE cl10 (for FAstrack Supreme20 only)

Does that not indicate that it should be faster than a standard GSM/GPRS connection?


#4

Hiya,

A couple of points:

  1. Does your Telco support EDGE in your area?
  2. What’s the Baud rate on the USB link?. Sounds stupid, but my (limited) experience is that the Wavecom ‘modem’ appears as a USB serial port - and you may need to up the baud rate. Also, if you are using a USB to Serial converter into the Supreme’s DB15 connector, you will definately be shifting data over a serial COM link. Have a look at the AT+IPR command in the doco for notes on how to change the DTE baud rate

Let us know how you get on.

ciao, Dave


#5

As already noted, the Fastrack isn’t a 3G device - so, if your phone is using 3G to achieve its data rate, the comparison is not valid.

Can you force the phone to use only EDGE (not 3G) and see how that compares?

The actual EDGE data rate provided by your carrier and/or your subscription could well be (significantly) lower than the theoretical maximum of the EDGE technology…


#6

That is correct.

You do need to specify a baud rate, but my understanding (which is also limited) is that this is purely for backwards compatibility and has no real effect on the actual transfer speed?

Absolutely.


#7

Agreed. :wink:

I don’t think so, can’t find any user configurable parameters for it. :confused:

:slight_smile: I believe you have hit the “nail square on the head”, I am using USB for my Fastrack Supreme / internet connection and was told to basically ignore the port set-up as it had no effect on USB.
It was set to: 115200,8,n,1, None, I have now set it to: 921600,8,n,1,Hardware.
I have just tried a 12MB download and achieved an average data rate of 22-23KB/Sec :smiley: , far better than my previous best of approx. 13-14KB/Sec :frowning: .
I also noticed that when I set the port baud rate to 921600 in “Hyperterminal”, followed by AT+IPR? it immediately replied with the new baud rate. :astonished:
Thanks to both of you for your help, very much appreciated. (I’ll now be able to reply a bit quicker next time! :wink: ).