how bandwidth superposition

2 wireless Internet access, the same isp, how bandwidth superposition, 2m + 2m = 4m
Another problem, how to use the new version “ip cloud”,what effect can be achieved?
please help

You can have only one route to 1 isp at the same time.
You can never do 2 ISP fuse together. (2+2=4 can not be reached)
You can configure load balancing but you can not increase the bandwidth
http://wiki.mikrotik.com/wiki/Load_Balancing_over_Multiple_Gateways