I am also using the 7.2Mbps mobile broadband around North area, mostly woodlands and cck. and I am only getting average 0.5Mbps DL and 0.4Mbps UL for the past few weeks, previously I was still able to hit average 4Mbps DL.
Seems like starhub is not bothered about ensuring bandwidth for its subscribers. Instead of trying to solve this problem by checking their infrastructure, they are letting me exit my contract without penalty, telling me that they can't do anything about it.
Right now I believe there are complains for all telcos, none of the telcos seems to be able to provide consistant bandwith throught the whole of singapore.
Right now I feel that the regulatory boards are not the pushing the ISPs to provide a acceptable minimum level of service to their customers in terms of advertised UL and DL bandwidth versus actual UL and DL bandwidth.
If only ISPs are able to sell their service in terms of minimum guaranteed bandwidth instead of maximum achieveable bandwidth....
At the moment, we can't do much about it, either don't use mobile broadband or subscribed to a lower speed to minimize overpaying the ISPs.