No, definitely not “the same” as in “equal” (===). A close approximation? Maybe.
Resource Constrained Devices (ie: Phones, Tablets, etc) have more resource constraints than just network bandwidth and latency that is emulated with traffic shaping. They also have constrained CPUs, power sources, memory, GPUs, etc compared to desktop counter parts. Sometimes they also have older browsers (ie: old iPhones that won’t upgrade past a certain iOS version).
So what is the purpose of testing your site for mobile 3g devices? That purpose statement will dictate if you need to invest in some mobile devices for testing.