So when I switched from ATT to Tmo my blackberry I was told was now running on 2g rather than the original 3g. The phone died shortly after I switched so I didn't really get a chance to check the speed. Anyway, it was somthing tmo told me, is it true or is it something they say to get you to buy their phones? If it's true, is it the carrier switching or unlocking process that causes this generational change? I ask because I see a 4g phone on ebay I may want to buy that says it's unlocked for any carrier, I don't know who the original carrier was or if it matters. Thanks!
TMO uses 1700 band (I think). ATT doesn't. Newer phones might have both 1700 and 1900. I've bought unlocked European phones and used them on TMO. Either Edge or GPRS. Since I use my wifi more than data, no problem. Didn't bother voice or text.
Okay thanks. I am still not completely clear though? Can the act of unlocking solely change the the speed from 4G to 3G? Meaning if it's a TMO phone, the other person unlocks it, you then use it on TMO, would it go down a generation? Versus switching from TMO to ATT or ATT to TMO as well as unlocking.
No, unlocking does not cause a speed decrease. Unlocking just makes it so you could switch carriers, if you desired. I don't know which way it is, but if you go from AT&T to T-Mo, or maybe the other way around, you won't get 3G. One carrier uses 2 bands for uplink/downlink and the other uses 1 band for both. So if you take a phone meant for the dual channel and put it on the network that only has 1 channel, it can't use 3G. The phone reverts to 2G. That may be what you have heard of. If I had to guess, I think you can move T-Mo to AT&T without a problem, but if you take AT&T to T-Mo, you get 2G only. If I remember the way my coworkers with T-Mo explained it right.
OK that helps a lot. I moved from ATT to TMO. But that TMO BB phone died so now I am in need of a new phone. I guess that means I need to look for a TMO one because if I find a ATT one then I risk speed issue decreases. No need to pay for 4G phone but get 3G.
