Experiences with external UMTS dongle

Alexander Lehner lehner at edv-buero-lehner.de
Sat Jul 4 18:24:34 CEST 2009

On Sat, 4 Jul 2009, Werner Almesberger wrote:

> Timo Juhani Lindfors wrote:
>>> My assumption is, that it takes far more than 2.5W, since the USB dongle
>> How about measuring that? Just read the current_now file in /sys.
> Telephony can have very high current peaks, in the order of 2 A.
> They are only short, i.e., the size of some transmit time slots,
> so the average current is much lower, but if a design doesn't
> adequately buffer those peaks, there will be problems.
> Problems should get worse in areas with poor or no reception.

Yes, that makes absolutely sense. As soon as I started to transmit some 
more data than only a ping or nslookup, the connection was gone.
Also, I _am_ in a region with poor reception, and I have only GPRS, no 

So maybe Timo has better reception conditions or the better hardware 
around the Huawai chip. I have an UMTS dongle from FONIC which uses the O2 
Network (whuaaa...).


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