What upload speed should I expect to be available to my users? This is for image attachments to emails.
A test we did over the phone for one user came out to about 100 kilobits per second.
The reason I ask is I am not sure if my unloader is creating an unusual amount of latency (edit: I mean time wasted between actual upload of a chunk). It uploads in parts using separate HttpPost requests and it base64 encodes the parts and sends them as POST parameters instead of using a “multipart file upload” like a browser would do.
This is the only test I have done with an end user and I don’t actually own an Android phone.
100 Kbps does not seem so bad. The actual max speed for UMTS is 384 Kbps, but I never saw more than 250 Kbps, and that’s with a very good signal. HSUPA speeds, on the other hand, can be 10 fold faster, but there are just a few phones in the US supporting it, with a lot more in Europe. Given the really big variability in speed due to signal issues, my guess is that it won’t be a bottleneck in your software. You should, nevertheless, consider that phones can get into 2g zones still or even loose signal in the middle of the transfer. A failure due to a loss of signal is a much worst problem for the end user than a couple more seconds waiting for the transfer (which, anyway, should be done in the background).