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Why Unlocked Phones Don't Work In the US
schnell writes "Unlocked cellular devices have long been a part of the wireless landscape in Europe and elsewhere. But longtime industry analyst Andrew Seybold explains why that model doesn't work in the US due to technology and frequency differences, and why LTE adoption may not make things any better."
NATO split up the spectrum after WWII so that European military radios were on the US civilian frequencies and vice versa. The reason was so the US military could take its radios into Europe and use their default channels and not conflict with the allied military radios that were already there.
Galaxy line uses micro USB.
"When the dominant model is to buy the phone with the plan"
Have you thought that it might be the case that that's the dominant model because that's all the telcos offer?
Nobody is telling that telcos should gift away expensive smartphones but that you should be able to choose between a locked subsidized mobile with a data plan *or* a cheaper data plan without the mobile.
I know it's against Slashdot tradition, but I'd recommend that you RTFA. The summary gave me the same impression - that it would be some corporate fluff piece about how it's a good thing that the networks are screwing you - but the article itself is actually a very well reasoned technical explanation of the various bits of spectrum (and the the protocols running on them) in use today and in the near future, and how these often interfere with interoperability.
Yeah Japan is even worse than the US in that regard - although SoftBank runs a GSM network so theoretically an unlocked quadband GSM phone (like the iPhone 4) should work in both the US and Japan with just a SIM card change.
I say 'theoretically' though because although there's no ~technical~ reason why this can't work, it won't work in practise since they won't let the phone actually connect to the network unless its a recognised IMEI from a contracted phone that they already sold you ;)
There is a reason for that: after the EU said "either you lot pick a single charger plug or we'll do it for you", the phone manufacturers decided to standardize on micro USB. You'll find that most of the other differences between the US and EU cell phone markets are also due to pressure from the EU: cell operators are not nicer on this side of the pond, they are just kept on a tighter leash.
Not on 3G, but if your phone supports the European 3G bands it'll work fine in Japan. My N900 served me quite well while I was over there in August on NTT DoCoMo's FOMA 3.5G network, even all the way out in Tochigi prefecture.
Of course, I only get 2.5G in the US on AT&T, but them's the breaks when you buy what you want rather than what you're offered.
Unfortunately, a standardized plug does diddly if you don't standardize how to charge.
There are a few billion ways you can charge from USB. There's the good old dumb "assume 500mA" method - where you assume you can draw 500mA from USB. Works fine for PCs and their chargers, but not so much if your USB host is power-limited.
Then there's the USB charging spec - where the charger shorts D+ and D- lines, and the device assumes it can draw the appropriate amount of current as the charger it comes with - 500mA, 800mA, 1A, 2A. Again, no standard on how to pick the current, so a device is free to draw as much as possible.
There's the Apple method, where resistors on D+ and D- lines tell the device how much power the charger can provide to prevent drawing too much power (iPods start at 100mA until enumerated at 500mA or more, or connected to a charger where it can select 500mA, 1A or 2A).
There's also using the ID line with resistors that identify the device - an ADC converts the voltage to identify the accessory (charger, car kit, high-current charger, etc).
There's also the USB high power spec, but that's for USB hosts that can provide more power.
Even worse, I've seen some devices destroy the charger because they assume the manufacturer's charger and draw more current than the charger can provide.
Fun fun fun.
Anyhow, at least for iPhone users, you can buy iPhones in Canada which are fully unlocked from Apple stores in Canada. I've seen a number of US people come to Canada to buy unlocked iPhones.
Four-band GSM phones work fine in the U.S., and all over the world. T-Mobile has a pre-paid plan for 10 U.S. cents per minute for those who don't often use a cell phone. T-Mobile will unlock the phones for you when you have been on their network for 3 months, if I remember correctly.
When you arrive in Campos do Jordão, Brazil, for example, just buy a SIM card for $7.50 U.S., and you will have a local number to give to anyone you meet there. And, of course, Google has cheap rates to every country, so people in the U.S. can call you while you are in Brazil.
Actually MiniUSB is more fragile:
http://en.wikipedia.org/wiki/MiniUSB#Durability
The newer Micro-USB receptacles are designed to allow up to 10,000 cycles of insertion and removal between the receptacle and plug, compared to 1500 for the standard USB and 5000 for the Mini-USB receptacle. This is accomplished by adding a locking device and by moving the leaf-spring connector from the jack to the plug, so that the most-stressed part is on the cable side of the connection. This change was made so that the connector on the less expensive cable would bear the most wear instead of the more expensive micro-USB device.