"NO CARRIER" problem

Hi,

I have 22 calling modems and 500 waiting for calls. (wavecom fastrack supreme)
When I start one call (or two) everything is OK, it connects without a problem

But when i start 7 or 8 calls in the same time, most of calls respond “NO CARRIER”. GSM company says that the signal is strong enough.
After “NO CARRIER” reply, “AT+CEER” command replies error number 47(sometimes 127).

What do You offer?

Thanks in advance.

Have you checked - eg, with AT+CSQ :question:

have you looked-up the meanings of error numbers 47 and 127 :question:

Yes I have checked “AT+CSQ” command before, it gives me “28, 0”.

error 47 is “Resources unavailable, unspecified”
error 127 is “Interworking, unspecified”

The ADL User Guide tells you that these are, “Failure Cause from 3GPP TS 24.008 recommendation (+CEER)”

You can find all the 3GPP Specifications (ie, the GSM specs) here:

3gpp.org/Specification-Numbering

You can download the specs for free - including TS 24.008

See TS 24.008 for further details of the cause codes…

Sorry but i did not figured out what should i do with specification

ie, you read it to get a more detailed description of what the codes actually mean!