Singapore government has confirmed that they will shut down 2G or GSM network:-
“The Infocomm Development Authority of Singapore (IDA) has approved the request of the mobile network operators (MNOs) – M1, Singtel Mobile and StarHub Mobile – to close their 2G networks with effect from 1 April 2017.“
Therefore, for Singapore, there is no choice and all equipments must move to 3G.
If you are currently using GSM/SMS modem that only supports 2G network (e.g. Wavecom M1306B, Wavecom Supreme 10, Sierra Wireless FXT009) we recommend MOBITEK® S80.