I've got my EVO on WCDMA only, and it works perfectly in Chicago, so not sure what you are saying about WCDMA being "GSM" technology...
You're probably exploiting some hole in the whole EVO/Network-app combination - strictly in my guessing mode - because the EVO processor can support a GSM radio and a CDMA radio (we just have the one, CDMA, for 3G).
The correct setting is indeed CDMA Auto (PRL).
The Network app is a much nicer, safer way to get to settings in the service menu - but - let's face it, those are service menu settings, so what does that tell you? (Tells me while it's kinda ok to go there, we shouldn't needing to be.)
When this whole radio thing flared up, I tried it out, thought it might have made a difference, but later decided it was more likely a placebo in my case.
So, I checked back to earlier threads and the back story goes like this:
- The buddy or buddies that originally figured this out also figured out that this seemed to be an early release issue - some phones were set wrong, some were set ok.
- The ones set wrong - yeah, it made a big difference in battery because it stopped the phone from schizophrenically trying to figure out what towers to talk to. (And there ARE hacks that will let you sneak your EVO to the wrong towers (shudder) - but this Network app isn't one of them, per se.)
- My theory is that this idea got lost because of the distribution channels and heavy demand for the EVO.
- Mere mortal users couldn't correlate date purchased to an early unit with the setup problem or not.
- So, some unnecessary flaming over REQUIRED! vs. PLACEBO! ensued in this forum.
- Some buddy - I'd cite and thank him here and now if I'd written down his name - in this forum explained the whole PRL update thing, that it bypassed this whole set radio business. I was a newbie, he had a bazillion posts and a bathousand thanks to his credit, so I believed him.
- I tried the PRL update, and whatever I thought I was seeing with the radio/Network app trick went away and my phone just seemed somehow more stable/better. I offer no rational words, but we all know when something's right and you can't explain how you know. Some combination of leveling out of my network traffic (I monitor it) and battery usage.
I even tried to force the phone into whacked radio states with the Network app - and I could. When I did, it just stopped, dialoged me, kinda reset itself (not full boot) and when it was done, Network app told me I was back to CDMA Auto (PRL).
And what does the PRL Update do? It give your phone the info so that it's not schizophrenic about what towers to use - same thing, in the end.
I've since been through two full 3G radio upgrades, each time, I check for a PRL Update, and that's kept me good to go.
If you agree with me, keep the Network app as a bullet in your gunbelt in case there's some update screwup some day - otherwise, forget it.
If you still question if CDMA is the right setting, consider these links in light of the fact that your phone's status bar says EV-DO when doing its 3G thing:
Evolution-Data Optimized - Wikipedia, the free encyclopedia
That guy says: EV-DO is CDMA.
W-CDMA (UMTS) - Wikipedia, the free encyclopedia
That last guy says nothing about EV-DO.
Hope this helps.
PS - I welcome correction and a better explanation by any old hand out there!!!!! But - I'm pretty sure I have this all correct.
