UTRAN/UMTS preferred



we’re using the Sierra Wireless Q26 Extreme to upload large amounts of data from sensor nodes and are having some trouble finding documentation (well, informative documentation) on the different network selection modes possible with AT+WWSM.

The default value of AT+WWSM seems to be an automatic selection between GERAN and UTRAN. It’s not clear from the documentation how this automatic selection is done. Maybe there’s and industry standard that we’ve missed that makes this obvious to someone who is well read on the subject?

On the same exact position, we see a drastic increase in upload speed when UTRAN (UMTS) is selected by the modem. Either, the network suddenly becomes much better and the modem therefore selects UTRAN/UMTS, or there is some randomness to which network is selected. There is another mode, besides automatic, which is called “UTRAN preferred”. Does anyone know what this does or know where there is some more extensive documentation for that setting?

Best regards



If you observe the AT command guide you can see that for “prefer_nwk” parameter 0 i.e. Automatic is default value. I guess the default settings will allow the automatic selection of either 2G or 3G Network. If UTRAN preferred is selected, Wireless CPU will select 3G network as soon as it is available. If 3G is not available, it will then select 2G network. I think you can refer 3GPP spec 43.318 , if you need more information.


are you able to establish UMTS conections? What firmware version?