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How (and how well) do Wireless "Worldphones" Work?
Milo_Mindbender asks: "I've seen a number of new phones (like the Sony T616) advertised as 'worldphones' that handle three or four GSM bands. As someone who travels to Japan and Europe occasionally I'm wondering how (and how well) these actually work. Can you get a temporary or prepaid SIM with a local carrier and just swap it or are the US carriers 'service locking' phones so you have to do international roaming with them even in foreign countries?"
To roam, you need two things. Hardware that works in the area you're using it in - if GSM, there are 3 frequency bands and a lot of new handsets support all of them.
You next need a phone company to service you - if in a foreign country this means either your service provider has a roaming agreement with a foreign service provider, or you stick a new SIM in the phone from a new service provider.
the latter option will change your phone number.
Fairly simple, really - just ask your phone company.
Second, if you buy the phone from the carrier, it will be locked and will not allow you to use a SIM card from another carrier. However, you can usually get the unlock code after you have had the phone awhile - T-mobile has been known to give out the unlock codes after 90 days.
You could also buy an unlocked phone from an independent dealer, but understand that this will cost significantly more. Unlocked phones *will* work with US carrier SIMs.
Jeff
Before this gets out of hand, most of the US is not on GSM. Two issues here:
* the frequency bands allocated (the 4 bands supported by these GSM phones) and
* the encoding (GSM, CDMA, TDMA)
GSM is gaussian shift keying (overlapping gaussian shaped pulses)
CDMA is code-division mux'ing (using the real & imaginary parts of the signal as bits)
TDMA is time-division mux'ing (splitting up the signals into time slots)
Switching was a royal pain in the ass, since they had totally replicated everything staffing-wise and billing-wise and all that, for the new network, and at that point, folks still weren't very clear on where to forward existing customers who wanted to switch. Eventually, though, I got a nice shiny Nokia 3650 (at no small expense).
At that point in time, I was told up front that GSM was pretty much available only in and around the biggest town in the area (where, conveniently, I live), and that service would be coming soon further out (where TDMA service already was, and had been, available). Okay, no problem.
10 months passed. I noticed that there my coverage wasn't nearly as good as it had been. More than about 10 miles from town in any direction and I had no service. I went for a long bike ride, spent 7 hours incommunicado, and my wife was calling hospitals to see if my body had been brought in.
Why did all this happen? Simple. The Nokia 3650 is a 900/1800/1900MHz "World Phone." Here in town, ATT's tower has GSM on 850/1900MHz... everywhere outside town it's 850MHz only. Whoops, ATT.
Oh, and of course you can go to any ATT kiosk or store in town and buy a 3650 to this day. The new 3620 (850/1900MHz, yay!) isn't yet available in stores... but it will be, soon... I hope...
CDMA networks (like Sprint and Verizon)
GSM/GPRS networks (like T-Mobile and Cingular)
Nort America Coverage Map
Typical US markets are a mix of the following: (800=800 MHz; 1900=1900 MHz)
800 AMPS
800 TDMA
800 CDMA (verizon)
800 iDen (nextel)
1900 CDMA (sprint pcs)
1900 GSM (at&t, cingular, t-mobile)
1900 TDMA (at&t)
I got an old Motorola Timeport P7389 that is unlocked and a new Nokia 6600 which is also unlocked. They work well across networks, I travel to the Philippines, Belgium, US and Canada and I just get a prepaid SIM card whenever I change locations. I avoid international roaming for security purposes especially the Philippines where crime is rampant.
You can get your phone unlocked at a lot of places here in Toronto, you should be able to get your phone unlocked if you live at any urban place as well. If you are lucky to have a Nokia you can get a DCT4 calculator (googled "free DCT4 calculator") and unlock the phone yourself, I've done that with my Nokia 6600 and my mom's Nokia 6610 as well.
My parents get international roaming on their Sim cards when they come to Canada (safe place as it is) and use their existing cell phones (all Nokia world phones) from the Philippines, works pretty well.
Archie - CIO-for-hire
This is not true, I took my t-mobile phone to India and used a pre-paid sim there. I simply had to email sim-unlock@tmobile.com to get instructions to unlock my phone, and tell them I was going on a trip.
Guess you dont get out much then.
TMobile has pretty much always had removable sim cards. Why? Because it is one of the few cell phone companies selling in the US market with a large worldwide romaing plan. How did this come about? Because TMobile is actually an international company.
And to think you got moderated informative. Too bad there isn't a misinformative option.
----- LoboSoft specializes in Digital Language Lab
I travel (not as frequently as I would like) to Europe and have lately been taking a Motorola P7389 tri-band GSM phone on my travels. The phone, while not the latest model, works great. I purchased it, unlocked, on eBay for short money.
On my latest trip, I purchased a Vodaphone NL from the cell phone kiosk at Schipol airport (the Netherlands) for about 20 Euro. It came with a number that is good for at least a year, and included 5 euros of credit. To top up the service, I only had to go to any of a number of outlets wherever I was in Holland, or if I could read and write Nederlands a little better, could refill the service from the internet site. Oh yes; all incoming calls (including international ones) were free. The in-country rate was less than I pay for my contracted Alltel phone here in the states.
I had the same experience in Greece and Beligum with different carriers.
I like the GSM system because it doesn't because of the flexibility it offers. If my phone dies, I can simply remove the SIM card from it and put it in another phone. I haven't verified this, but heard while I was in Europe that the EU has mandated that all phones sold in EU countries are requried to be unlocked.
GSM is a standard throughout the world (except for the US, Iraq, Afganistan and I believe, Argentina). An excellent site for finding out about prepaid GSM services is http://www.prepaidgsm.net/,
Don't be fooled by "word phones" offered by various US carriers. These phones are locked tri-band phones that roam on European GSM networks, but which are charged at outrageous rates by the US company.
wherever I go, there I am.
Actually, any carrier in the US (world) that uses the GSM spectra, either in the 800, 850, 1800, or 1900 MHz bands have to use the SIM cards. To my knowledge, those carriers include, but are not limited to:
Cingular
AT&T Wireless
T-Mobile
Nextel (the original walkie-talkie cellphone people) has been using SIM chips in the last two generations of their phones, the i35sx thru i95cl (now being phased out) and the newer, 'Condor-series' phones, the i205 thru the i730; but, these phones do not work on *any* GSM spectra, they work on the propietary iDEN network made by Motorola.
Sprint is a PCS provider. I'm unaware of any international PCS provider, either in existance, or that is compatible with Sprint PCS.
Verizon is currently CDMA 1xRTT, which is incompatible with GSM. They also do not utilize SIM chips in their handsets.
As I walk through the valley of death I fear no one, for I am the meanest sonova bitch in the valley!
If you research it it is far less restrictive, you just have to pick the right carrier.
... if it does see if it handles the GSM 850 stuff and if so call AT&T to see if they will unlock the phone for you. If AT&T matches all of those criteria, they may work better for you. Otherwise I highly recommend T-Mobile for international solutions.
... N. Ireland is part of the UK so their code is +44, not +77. That one got me for a day or so of trying to contact a friend since all they mailed was their number without the code.
I went to Ireland earlier this month and so I picked up a T-Mobile T610 and away I went. I didn't have it long enough to experiment with swapping the SIM with a prepaid, but all of T-Mobile's phones have the SIM card.
Apparently if you call 611 after having had the phone at least 2 weeks (I hadn't when I went) there are people who report online that T-Mobile will unlock your phone so that you can use a pre-paid.
I was a T-Mobile customer in the past (I had a couple years where a cellphone didn't make sense) and my wife and I both had phones. When my battery was down while we were travelling if I needed to make a call that would be billable to work I just swapped our chips for a bit.
While T-Mobile is a European company, I was a Voicestream customer before T-Mobile bought them and a Powertel customer before Voicestream bought -them- and all had SIM cards.
As for reception, the T610 worked perfectly over there. I think it is a tri-band phone so you'll get reception in GSM 800, GSM 1800 and GSM 1900 markets if I remember right. I was roaming on Vodaphone, Orange and O2 just fine. Each had their quirks (I couldn't check voicemail the normal way on one, another had to dial for awhile to connect to a WAP server instead of having an almost instant "ON") but nothing that stopped me from service. WAP worked everywhere as did SMS.
AT&T is converting their analog 850MHz to GSM, so there is another band out there that is GSM 850. I wish my T610 handled the AT&T GSM 850 frequencies since AT&T is the only carrier in my small neck of the woods. I don't know if the AT&T T616, which is basically the same phone but there are always differences, has a SIM card
Oh and a hint if anyone is going to be in Ireland and gets a phone number from someone in N. Ireland
It is more productive to voice thoughtful opinions (reply) than to judge (moderate) others.
Slight correction....
PCS is the name that Sprint operates under and the name for the 1900 MHz band that they operate in.
Sprint PCS is CDMA 1xRTT or CdmaOne (the slower, 2G predecessor to 1xRTT) like Verizon.
But you are right in that neither the CDMA (IS-95) nor the TDMA (IS-136) standards include the notion of a SIM card in the standard, so nobody has one.
Gentoo Sucks
Another great thing about T-Mobile is that they have the geekiest add-on service of any mobile phone company. All you can eat GPRS data transfer is $20 extra per month. So is all you can eat 802.11b Hot Spot service. Of course getting both will set you back $40 extra per month. And you have to have a $30/month or more phone plan to get the deal on GPRS. My $20/month econo plan doesn't count. However, it's sufficient for the $20 a.y.c.e Hot Spot deal.
Oh yeah...phone sound quality and coverage rocks here in Los Angeles. Of course, they are using the same network as Cingular here, so Cingular users can probably say "Oh yeah? Mine's just as good." Cingular doesn't have the geeky propellerhead extra goodness, though. ^_^
Knowledge is power. Knowledge shared is power multiplied.
In order to use your gsm sim in Japan you need a 3g w-cdma handset, some include support for european gsm 900 & 1800 such as the nokia 6650 but I haven't seen one that works in the US as well... T-Mobile and probably other us carriers have roaming agreements with J-Phone and some J-Phone handsets will accept your sim card.
the t616 does have a sim card.
the t616 and t610 are basically the exact same phone, except the frequencies they operate on. the t616, sold only by at&t and maybe cingular is 850/1800/1900. whereas the t610 is 900/1800/1900