3G is not really a specific standard, it's more like a bunch of technologies that include UMTS, W-CDMA, HSPA+. So both the uplink and downlink are 3G, but only the downlink is 3.5G. The uplink doesn't have a specific "G" name because it's mostly the marketing people that come up with this **** and nobody cares how fast their phone can upload data... (2mbit for ours if you're wondering).
I don't know how the hardware radios work, but I thought maybe if it's connected to different bands, it could report the signal strength for each one individually. If they had programmed an interface for that, which they didn't do.