E220 HSDPA Study

There are three devices will appear in system when E220 USB device plug-in (with driver installed).

1. Mass storage device (include driver, application and manual)
2. 3G modem device (COM)
3. Mobile Connect PC UI Interface device (COM)

There is a application called “Mobile Connect” will be installed with 3G modem driver. Which will use the 3th device in above list to communicate with 3G chip. (cause the 3G modem device has been locked by windows connection manager when connected, the application need another interface to get statistic from 3G chip)

We can open the PC UI interface with baud rate 60800. Suppose it can support all AT commands (I had tested “AT” and “AT+CSQ” only).

There are some auto push messages from PC UI interface:

• ^BOOT, n, n, n, n, n
  No idea.
• ^RSSI, n
  Get signal strength level in 0~31. Equal to (n * 2 – 133) dBm.
• ^MODE, n1, n2
  3, 2: GPRS
  3, 3: EDGE (what is this?)
  5, 4: UTMS
  5, 5: HSDPA
• ^DSFLOWRPT, n1, n2, n3, n4, n5, n6, n7
  n1: connection duration in seconds
  n2: Transmit speed in bits per second
  n3: Receive speed in bits per second
  n4: Transmit bytes
  n5: Receive bytes
  n6: No idea
  n7: No idea

And here are some configure commands:

• AT^SYSCFG=2,1,3FFFFFFF,1,2
  Configure device for GPRS/DEGE preferred.
• AT^SYSCFG=2,2,3FFFFFFF,1,2
  Configure device for 3G (UTMA/HSDPA) preferred.
• AT^SYSCFG=13,1,3FFFFFFF,1,2
  Configure device for GPRS/DEGE only.
• AT^SYSCFG=14,2,3FFFFFFF,1,2
  Configure device for 3G only.

And here is the definition of the parameter “3FFFFFFF” in above commands:

• 3FFFFFFF: Use all bands
• 00400380: GSM900/1800/WCDMA2100
• 00200000: GSM1900 only

All messages and commands are found on google, which are tested by some Linux user. The specification of  PC UI interface is not a open SPEC.