chan_quectel channel driver for Quectel LTE cards

WARNING:

This channel driver is in alpha stage. I am not responsible if this channel driver will eat your money on your SIM card or do any unpredicted things.

Please use a recent Linux kernel, 2.6.33+ recommended. If you use FreeBSD, 8.0+ recommended.

This channel driver should work with the folowing PCIe cards:

• Quectel EC25-A
• Quectel EC25-AF
• ...

Check for details here: https://forum.gl-inet.com/t/gl-mifi-ec25-af-asterisk-voice-channel/

Before using the channel driver make sure to:

• Disable PIN code on your SIM card

Supported features:

• Place voice calls and terminate voice calls
• Send SMS and receive SMS
• Send and receive USSD commands / messages

Some useful AT commands:

AT+CCWA=0,0,1                   #disable call-waiting
AT+CFUN=1,1                     #reset quectel
AT^CARDLOCK="<code>"            #unlock code
AT^SYSCFG=13,0,3FFFFFFF,0,3     #modem 2G only, automatic search any band, no roaming
AT^U2DIAG=0                     #enable modem function

Building:

$ ./bootstrap
$ ./configure --with-astversion=13.7
$ make

If you run a different version of Asterisk, you'll need to update the 13.7 as appropriate, obviously.

If you did not make install Asterisk in the usual location and configure cannot find the asterisk header files in /usr/include/asterisk, you may optionally pass --with-asterisk=PATH/TO/INCLUDE.

Here is an example for the dialplan:

WARNING: This example uses the raw SMS message passed to System() directly. No sane person would do that with untrusted data without escaping/removing the single quotes.

[quectel-incoming]
exten => sms,1,Verbose(Incoming SMS from ${CALLERID(num)} ${BASE64_DECODE(${SMS_BASE64})})
exten => sms,n,System(echo '${STRFTIME(${EPOCH},,%Y-%m-%d %H:%M:%S)} - ${QUECTELNAME} - ${CALLERID(num)}: ${BASE64_DECODE(${SMS_BASE64})}' >> /var/log/asterisk/sms.txt)
exten => sms,n,Hangup()

exten => ussd,1,Verbose(Incoming USSD: ${BASE64_DECODE(${USSD_BASE64})})
exten => ussd,n,System(echo '${STRFTIME(${EPOCH},,%Y-%m-%d %H:%M:%S)} - ${QUECTELNAME}: ${BASE64_DECODE(${USSD_BASE64})}' >> /var/log/asterisk/ussd.txt)
exten => ussd,n,Hangup()

exten => s,1,Dial(SIP/2001@othersipserver)
exten => s,n,Hangup()

[othersipserver-incoming]

exten => _X.,1,Dial(Quectel/r1/${EXTEN})
exten => _X.,n,Hangup

exten => *#123#,1,QuectelSendUSSD(quectel0,${EXTEN})
exten => *#123#,n,Answer()
exten => *#123#,n,Wait(2)
exten => *#123#,n,Playback(vm-goodbye)
exten => *#123#,n,Hangup()

exten => _#X.,1,QuectelSendSMS(quectel0,${EXTEN:1},"Please call me",1440,yes,"magicID")
exten => _#X.,n,Answer()
exten => _#X.,n,Wait(2)
exten => _#X.,n,Playback(vm-goodbye)
exten => _#X.,n,Hangup()

You can also use this:

Call using a specific group:

exten => _X.,1,Dial(Quectel/g1/${EXTEN})

Call using a specific group in round robin:

exten => _X.,1,Dial(Quectel/r1/${EXTEN})

Call using a specific quectel:

exten => _X.,1,Dial(Quectel/quectel0/${EXTEN})

Call using a specific provider name:

exten => _X.,1,Dial(Quectel/p:PROVIDER NAME/${EXTEN})

Call using a specific IMEI:

exten => _X.,1,Dial(Quectel/i:123456789012345/${EXTEN})

Call using a specific IMSI prefix:

exten => _X.,1,Dial(Quectel/s:25099203948/${EXTEN})

How to store your own number:

quectel cmd quectel0 AT+CPBS=\"ON\"
quectel cmd quectel0 AT+CPBW=1,\"+123456789\",145

Other CLI commands:

quectel reset <device>
quectel restart gracefully <device>
quectel restart now <device>
quectel restart when convenient <device>
quectel show device <device>
quectel show devices
quectel show version
quectel sms <device> number message
quectel ussd <device> ussd
quectel stop gracefully <device>
quectel stop now <device>
quectel stop when convenient <device>
quectel start <device>
quectel restart gracefully <device>
quectel restart now <device>
quectel restart when convenient <device>
quectel remove gracefully <device>
quectel remove now <device>
quectel remove when convenient <device>
quectel reload gracefully
quectel reload now
quectel reload when convenient

For reading installation notes please look to INSTALL file.

Gain control and Jitter buffer

In order to perform good quality calls you will need to take care of:

• Automatic gain control:

chan_quectel does not control the gain of the audio stream it receive. This result of Alice hearing Bob's voice loud and noisy. It is possible to manually manage the gain in quectel.conf but the better option is by far to apply automatic gain control with the dialplan function AGC.

• Jitter buffer:

Since asterisk 12 it is no longer possible to enable Jitter buffer in quectel.conf it has to be applied in the dialplan. The lack of Jitter buffer result in severe loss in the transport of the voice from Bob to Alice.

Dialplan example

To set JITTERBUFFER and AGC in the dialplan on the appropriate channel regardless of who is initiating the call we will have to use the "b" option of Dial:

b( context^exten^priority )

Before initiating an outgoing call, Gosub to the specified location using the newly created channel.

The Gosub will be executed for each destination channel."

[from-quectel]
; This will be executed by an indbound Quectel channel ( call initiated on the quectel side )
exten => _[+0-9].,1,Dial(SIP/bob,b(from-quectel^outbound^1)) ;

; This will be executed by an outbound SIP channel ( channel generated by dial )
exten => outbound,1,Set(JITTERBUFFER(adaptive)=default)
same => n,Set(AGC(rx)=4000)
same => n,Return()

[from-sip]
; This will be executed by an inbound SIP channel ( call initiated on the SIP side )
exten => _[+0-9].,1,Set(JITTERBUFFER(adaptive)=2000,1600,120)
same => n,Set(AGC(rx)=4000)
same => n,Dial(Quectel/i:${IMEI_OF_MY_QUECTEL}/${NUMBER_OF_BOB}) 

Note: To use automatic gain control dialplan function (AGC) you will need to compile Asterisk with func_speex ( see in menuselect ). On raspberry Pi you will need to compile and install speex and speexdsp yourself, the version of speex provided by the depos does not support AGC. (because compiled with fixed point instead of floating point) see: HOWTO

For additional information about Huawei dongle usage look to chan_dongle Wiki at http://wiki.e1550.mobi and chan_quectel project home at https://github.com/t4rd15/asterisk-chan-quectel/