Hi Piclisters!

I'm using a TCM3105 single chip modem to send data trhu the cellular network,
from a PIC16c65 mounted on a car to a PC. The data flow is "half-duplex",
only from the PIC. This chip uses FSK modulation (V21) and I tested it when
the transmitter is
moving and works fine, but is expensive and need a "custom" modem in the PC,
since
i cant found a modem card supporting V21.
Some people tell me that V22 and other modem standards that uses PSK or QAM
modulation
techniques are not useful in mobile applications. Is this correct?
Can I use a V22 chip?

Regards,
Ernesto Tolocka
etolocka@onenet.com.ar
Argentina