Device like this http://aldiga.com/english/A-100-USB-EDGE10.htm
contains Prolific 2303 chip.
Actually their site a bit outdated - I have AlDiga AL-11U
GSM/GPRS/EDGE modem and it works with pl2303 module after adding
corresponding product ID.

By default modem uses baud rate 460800.  GSM chipset - SIMCom SIM600,
quad band 850/900/1800/1900 MHz

Device info:

T:  Bus=04 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#=  5 Spd=12  MxCh= 0
D:  Ver= 1.10 Cls=00(>ifc ) Sub=00 Prot=00 MxPS= 8 #Cfgs=  1
P:  Vendor=067b ProdID=0611 Rev= 0.00
C:* #Ifs= 1 Cfg#= 1 Atr=a0 MxPwr=500mA
I:* If#= 0 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=00 Driver=pl2303
E:  Ad=81(I) Atr=03(Int.) MxPS=  10 Ivl=1ms
E:  Ad=02(O) Atr=02(Bulk) MxPS=  64 Ivl=0ms
E:  Ad=83(I) Atr=02(Bulk) MxPS=  64 Ivl=0ms

From: Max Arnold <lwarxx@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>