Editing Experiments on GSM/GPRS/HSDPA modem

== Modeswitch command for ZTE MF626 ==
 AT+ZOPRT=5 (TODO: is this really required?)
 ATZ+CPIN=<PIN>
 AT+ZCDRUN=8

Apparently, unmounting the mounted file system in Linux does the same thing as well.  I think unmounting only worked when I installed usb_modeswitch.

=== Port Settings ===
<pre>
Speed: 115200
Data bits: 8
Parity: None
Stop bits: 1
Flow Control: None
</pre>

== Notes ==
Once the modem has been initialized, it will start sending a stream of +ZUSIMR:2 messages.  It means that it doesn't know where to store the messages.  To solve this, issue the following commands to store it at the SIM card:
<pre>
AT+CPBS="SM"
AT+CPMS="SM","SM","SM"
</pre>

<!--
== Notes ==
Switching the compound device to modem gives /dev/ttyUSB0, /dev/ttyUSB1, and /dev/ttyUSB2.  Through trial and error, I've deduced that:
* /dev/ttyUSB2 is for monitoring (it sends a steady stream of +ZUSIMR:2)
* /dev/ttyUSB1
* /dev/ttyUSB0

I need to observe this more to confirm that this assignment is consistent.
-->

== Sending SMS ==
<pre>
AT
OK
AT+CMGF=1
OK
AT+CMGW="+639191234567"
> Hello world!
+CMGW: 1

OK
AT+CMSS=1
+CMSS: 20

OK
</pre>

== Scanning for Available Networks ==
<pre>
AT+COPS=?
+COPS: (1,"Smart Communications Inc.","SMART","51503",0),(2,"","","51503",2),(3,"Digital Telecommunications Phils,Inc","PH DIGITEL","51505",0),(3,"","","51502",2),(3,"Globe Telecom,GMCR Inc.","GLOBE","51502",0),

OK
</pre>

== TODO ==
* How to monitor signal strength?
** AT+CSQ
* How to read/write phonebook entries?
** AT+CPBS
* How to read/write/delete SMS messages from SIM card?
** AT+CMGR, AT+CMGL, AT+CMGD
* How to determine the SIM card's available storage space?
** AT+CPMS