Hello, I'm using a Huawei E1752Cu unlocked to any carrier, the E1752 is in the supported list.
I configured openwrt, everything working fine.
I moved router to an other house where I want to use it, I have no UMTS coverage.
It never connects, I have a "No carrier" error.
Everything looks to work OK in the router.
Must say my ISP/cell phone provider uses another carrier but in both modes UMTS and GPRS.
Using the 3g modem connected to the computer I have GPRS connection, just the software say I'm in Roaming.

Any help?
Thank you.

hi,
you have to add to your '/etc/chatscripts/3g.chat' script one of the following - depending on your signal type and preference:
    `GPRSONLY' : AT^SYSCFG=13,1,3FFFFFFF,2,4
    `3GONLY' :  AT^SYSCFG=14,2,3FFFFFFF,2,4
    `GPRSPREF' : AT^SYSCFG=2,1,3FFFFFFF,2,4
    `3GPREF' :   AT^SYSCFG=2,2,3FFFFFFF,2,4

but in your situation i believe it should be "3G preffered, Roaming is supported":
""      "AT^SYSCFG=2,2,3FFFFFFF,1,4"

as a reference: https://wiki.archlinux.org/index.php/Hu … 0_3G_modem

AT^SYSCFG=mode, order, band, roaming, domain - System Config

Mode:
2 Automatic search
13 2G ONLY
14 3G ONLY
16 No change

Order:
0 Automatic search
1 2G first, then 3G
2 3G first, then 2G
3 No change

Band:
80 GSM DCS systems
100 Extended GSM 900
200 Primary GSM 900
200000 GSM PCS
400000 WCDMA IMT 2000
3FFFFFFF Any band
40000000 No change of band

Roaming:
0 Not supported
1 Roaming is supported
2 No change

Domain:
0 CS_ONLY
1 PS_ONLY
2 CS_PS
3 ANY
4 No change

(Last edited by maurer on 19 Sep 2011, 07:42)

maurer many thanks !!!!

Please tell me if I did it correctly cause I have to go to the other house to test:

Something is wrong:

Mar 27 03:44:26 OpenWrt local2.info chat[1564]: alarm
Mar 27 03:44:26 OpenWrt local2.info chat[1564]: Failed
Mar 27 03:44:26 OpenWrt daemon.err pppd[1556]: Connect script failed
Mar 27 03:44:58 OpenWrt local2.info chat[1590]: expect (`3GPREF')

I'm so stupid!

Now I'm connecting but...
No navigation, no ping, no time servers...

Mar 27 03:56:30 OpenWrt user.notice ifup: Enabling Router Solicitations on wan (3g-wan)
Mar 27 03:56:31 OpenWrt user.info firewall: adding wan (3g-wan) to zone wan
Mar 27 03:56:41 OpenWrt user.notice rdate: Failed to sync with ptbtime1.ptb.de
Mar 27 03:56:51 OpenWrt user.notice rdate: Failed to sync with tock.usno.navy.mil
Mar 27 03:57:01 OpenWrt user.notice rdate: Failed to sync with ntp.xs4all.nl
Mar 27 03:57:06 OpenWrt user.notice rdate: Failed to sync with ptbtime2.ptb.de
Mar 27 03:57:06 OpenWrt user.notice rdate: No usable time server for wan found

no, add:
""      "AT^SYSCFG=2,2,3FFFFFFF,1,4"
after SAY    "Calling..."

NOW!!!!!!!!!

I only need to move to the other house to test in 2G mode, hope it works.

I added before SAY    "Calling..."
Is it OK or must I change?

yes, ok. test it.
you can test it without the need to physically move the modem
just change command to   `GPRSONLY' : AT^SYSCFG=13,1,3FFFFFFF,2,4
""      "AT^SYSCFG=13,1,3FFFFFFF,1,4"

(Last edited by maurer on 19 Sep 2011, 13:30)

Do not accept this command
Tested both
AT^SYSCFG=13,1,3FFFFFFF,2,4
AT^SYSCFG=13,1,3FFFFFFF,1,4

Sep 20 05:47:57 OpenWrt local2.info chat[3459]: AT^SYSCFG=13,1,3FFFFFFF,2,4^M^M
Sep 20 05:47:57 OpenWrt local2.info chat[3459]: COMMAND NOT SUPPORT^M

And looking at the log I see the "Original" command is not working:

Sep 20 05:51:55 OpenWrt local2.info chat[4380]: AT^SYSCFG=2,2,3FFFFFFF,1,4^M^M
Sep 20 05:51:55 OpenWrt local2.info chat[4380]: COMMAND NOT SUPPORT^M

I think my modem do not support this command syscfg

Sep 20 06:16:21 OpenWrt local2.info chat[5252]: AT^SYSCFG=?^M^M
Sep 20 06:16:21 OpenWrt local2.info chat[5252]: COMMAND NOT SUPPORT^M

(Last edited by Kgonla on 20 Sep 2011, 05:19)

I find the solution for AT command !!! BUT...

Mar 27 03:44:21 OpenWrt local2.info chat[1583]: send (AT\^SYSCFG=13,1,3FFFFFFF,1,4^M)
Mar 27 03:44:22 OpenWrt local2.info chat[1583]: timeout set to 15 seconds
Mar 27 03:44:22 OpenWrt local2.info chat[1583]: expect (OK)
Mar 27 03:44:22 OpenWrt local2.info chat[1583]: ^M
Mar 27 03:44:22 OpenWrt local2.info chat[1583]: AT+CGDCONT=1,"IP","internet"^M^M
Mar 27 03:44:22 OpenWrt local2.info chat[1583]: OK
Mar 27 03:44:22 OpenWrt local2.info chat[1583]:  -- got it
Mar 27 03:44:22 OpenWrt local2.info chat[1583]: send (ATD*99#^M)
Mar 27 03:44:22 OpenWrt local2.info chat[1583]: expect (CONNECT)
Mar 27 03:44:22 OpenWrt local2.info chat[1583]: ^M
Mar 27 03:44:22 OpenWrt local2.info chat[1583]: AT^SYSCFG=13,1,3FFFFFFF,1,4^M^M
Mar 27 03:44:22 OpenWrt local2.info chat[1583]: OK^M
Mar 27 03:44:22 OpenWrt local2.info chat[1583]: D*99#^M^M
Mar 27 03:44:22 OpenWrt local2.info chat[1583]: CONNECT
Mar 27 03:44:22 OpenWrt local2.info chat[1583]:  -- got it
Mar 27 03:44:22 OpenWrt local2.info chat[1583]: send ( ^M)
Mar 27 03:44:22 OpenWrt daemon.info pppd[1578]: Serial connection established.
Mar 27 03:44:22 OpenWrt daemon.info pppd[1578]: Using interface 3g-wan
Mar 27 03:44:22 OpenWrt daemon.notice pppd[1578]: Connect: 3g-wan <--> /dev/ttyUSB0
Mar 27 03:44:36 OpenWrt daemon.warn pppd[1578]: Could not determine remote IP address: defaulting to 10.64.64.64
Mar 27 03:44:36 OpenWrt daemon.notice pppd[1578]: local  IP address 109.227.188.188
Mar 27 03:44:36 OpenWrt daemon.notice pppd[1578]: remote IP address 10.64.64.64
Mar 27 03:44:36 OpenWrt daemon.notice pppd[1578]: primary   DNS address 213.248.76.210
Mar 27 03:44:36 OpenWrt daemon.notice pppd[1578]: secondary DNS address 213.248.100.54
Mar 27 03:44:37 OpenWrt user.notice ifup: Enabling Router Solicitations on wan (3g-wan)
Mar 27 03:44:37 OpenWrt user.info firewall: adding wan (3g-wan) to zone wan
Mar 27 03:44:42 OpenWrt daemon.info dnsmasq[1553]: reading /tmp/resolv.conf.auto
Mar 27 03:44:42 OpenWrt daemon.info dnsmasq[1553]: using nameserver 213.248.100.54#53
Mar 27 03:44:42 OpenWrt daemon.info dnsmasq[1553]: using nameserver 213.248.76.210#53
Mar 27 03:44:42 OpenWrt daemon.info dnsmasq[1553]: using nameserver 194.2.0.50#53
Mar 27 03:44:42 OpenWrt daemon.info dnsmasq[1553]: using nameserver 8.8.4.4#53
Mar 27 03:44:42 OpenWrt daemon.info dnsmasq[1553]: using local addresses only for domain lan
Mar 27 03:44:43 OpenWrt daemon.info pppd[1578]: No response to 5 echo-requests
Mar 27 03:44:43 OpenWrt daemon.notice pppd[1578]: Serial link appears to be disconnected.
Mar 27 03:44:43 OpenWrt daemon.info pppd[1578]: Connect time 0.2 minutes.
Mar 27 03:44:43 OpenWrt daemon.info pppd[1578]: Sent 236 bytes, received 0 bytes.

I'm going to test more configurations and see what happen.

With - "SYSCFG=2,2,3FFFFFFF,1,4" - I have connection
With - "SYSCFG=13,1,3FFFFFFF,1,4" - I have the problem above

If I change configuration from 2,2 to 13,1 and reconnect not rebooting router:

Sep 20 07:24:02 OpenWrt local2.info chat[2730]: AT^SYSCFG=13,1,3fffffff,1,4^M^M
Sep 20 07:24:02 OpenWrt local2.info chat[2730]: OK^M
Sep 20 07:24:02 OpenWrt local2.info chat[2730]: TD*99#^M^M
Sep 20 07:24:02 OpenWrt local2.info chat[2730]: NO CARRIER
Sep 20 07:24:02 OpenWrt local2.info chat[2730]:  -- failed
Sep 20 07:24:02 OpenWrt local2.info chat[2730]: Failed (NO CARRIER)
Sep 20 07:24:02 OpenWrt daemon.err pppd[2725]: Connect script failed

(Last edited by Kgonla on 20 Sep 2011, 06:45)

Well, I tested it in the other house and it is not working.
I have the "No response to 5 echo-requests." error.
This is the same than when forcing 2g connection, the modem connect but get disconnected after a few seconds.

kgonla - your issue is related to gsm/umts - not to openwrt/linux
try to post your question to http://www.draisberghof.de/usb_modeswitch/bb/ or even at huawei forum - you might have better luck there