Had to turn my phone on to see what it was displaying.
It seems that ideally it should be showing 3G, but it sometimes changes to H very briefly very now & again.
When data can't be delivered, then two curved arrowed in the form of an O appear, like a dog chasing it's tail.
I feel sure though that at times when poor old Optus has run out of puff, nothing displays until it can muster up enough strength to transmit a signal.
Don't know whether all ISP's in different countries display the same codes, but if they are 3G networks, I expect they would all display this when fully delivering.
It is 8.50 AM Saturday here, so not a lot of users would be out of bed and using Optus yet, - so that is why the 3G code is displaying pretty consistently.
And if you don't see those 2 little up and down arrows active, net to 3G or what ever code, don't even bother trying to use an app. the requires the Net, as there is no connection with Net and the App. will only try to load with that revolving circular arrow.
And that looks bad in the bus, - people may think there is a problem with the phone. So, just play a few YouTube videos from Gallery until those little arrows are back pumping away.