SimCom SIM900D EVB, Проектирование аппаратного обеспечения

Страница: 12 / 63

SIM900D Hardware Design
SIM900D_Hardware Design_V1.04 2010.10.09
12
Road safety comes first! Do not use a hand-held cellular terminal or mobile when driving a
vehicle, unless it is securely mounted in a holder for hands free operation. Before making a call
with a hand-held terminal or mobile, park the vehicle.
GSM cellular terminals or mobiles operate over radio frequency signals and cellular networks
and cannot be guaranteed to connect in all conditions, for example no mobile fee available or
with an invalid SIM card. While users are in this kind of condition and need emergent help,
please remember using emergency calls. In order to make or receive calls, the cellular terminal
or mobile must be switched on and in a service area with adequate cellular signal strength.
Some networks do not allow for emergency call if certain network services or phone features
are in use (e.g. lock functions, fixed dialing etc.). User may have to deactivate those features
before user can make an emergency call.
Also, some networks require a valid SIM card to be properly inserted into the cellular terminal
or mobile.