Mobile Phones & Broadband

[haases]

Hi,

I recently saw an "unlocked" phone offer on Amazon.com....... Could you please tell me whether "unlocked" phones, are usually wi-fi enabled?  Also, if one had such an

unlocked phone and placed into it a blank T-Mobile SiM card, would this phone, with its wifi ability, be able to do e-mail and get on to the internet withOUT a data-plan?

Peter

[xl]

Hmm...

• depends on the phone... not all phones are wifi.... which one are you interested in?
• some locked phones can be easier to unlock than others
• check the specs carefully.... in the old days, you can get any SIM card for GSM phone.... today different carriers are starting to use different frequencies.  I'm bought one too many mismatched SIM cards in my travels.
• how do you want your emails?  some phones are tightly coupled to an email server.... switching SIM cards will sever the connection..... however you will still be able to get to the emails via webmail.
• check out Blackberry's BBM!  It allows you send messages to other Blackberry users without a data plan.  It uses a paging network... archaic, but effective.

[haases]

Actually, I didn't have any specific handset/device in mind.  I had just heard that there are "unlocked" mobile phones out there (e.g. amazon.com, etc.).  Likewise, I had heard that some of these units are wi-fi capable and all you need to do is to insert a SIM card into them (I have a T-Mobile SIM card).  So, if what I heard is true, doesn't that mean that if I went to a Starbucks and "used" such a unit, I would be able to get on the internet and also do e-mail?

And...... If all of the above is true, what brand/model of a smart-phone handset/device should I be looking for that might sell for less than $100 at places like Amazonand?

[Entropy · Accepted solution]

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haases wrote:

Actually, I didn't have any specific handset/device in mind.  I had just heard that there are "unlocked" mobile phones out there (e.g. amazon.com, etc.).  Likewise, I had heard that some of these units are wi-fi capable and all you need to do is to insert a SIM card into them (I have a T-Mobile SIM card).  So, if what I heard is true, doesn't that mean that if I went to a Starbucks and "used" such a unit, I would be able to get on the internet and also do e-mail?

And...... If all of the above is true, what brand/model of a smart-phone handset/device should I be looking for that might sell for less than $100 at places like Amazonand?

---

Smartphones are wifi-enabled, so you can get data in places like McD's and Starbucks even without a data plan.

However - you are not going to see a smartphone for less than a few hundred dollars if purchased without a contract subsidy.

Note that an unlocked AT&T or international phone used on T-Mobile will be limited to 2G (EDGE) service, as T-Mobile uses a frequency band for 3G not used in many other countries.

[haases]

I forgot to ask.....  What role does a SIM card play in all this?  In orther words, if I can get my hands on (let's say) a discarded AT&T smartphone, and I remove its SIM card and replace it with my "old" T-Mobile SIM card, and since Smartphones are automatically wi-fi capable/equipped, couldn't I just go to Starbucks, etc. and get on the internet?

[Entropy]

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haases wrote:

I forgot to ask.....  What role does a SIM card play in all this?  In orther words, if I can get my hands on (let's say) a discarded AT&T smartphone, and I remove its SIM card and replace it with my "old" T-Mobile SIM card, and since Smartphones are automatically wi-fi capable/equipped, couldn't I just go to Starbucks, etc. and get on the internet?

---

A SIM is what your cellular account is tied to.

If you want to use ONLY wifi, not even make/receive calls, you don't need a SIM at all.

Note that there are MP3 players such as the Galaxy Player 4.0 and 5.0 that cost around the same as a similar unlocked device on the used market (actually probably a bit cheaper) and are pure wifi-only devices.

To use a T-Mobile SIM in an AT&T phone to make and receive T-Mobile calls, you must unlock the AT&T phone.  As said before - this will be limited to 2G service only, which might not be a big problem if used only for voice, but TMo might start having areas that only offer 3G coverage and not 2G.

[jpf0525]

I am interested in purchasing a unlocked phone but know there are differences in cdma and gsm. I'm i...or any motorola android phone really. To be used with Boost Mobile, any suggestions?

[jpf0525]

I am interested in purchasing a unlocked phone and not sure what works with what. I have boost and am interested in any motorola android phone. Any suggestions? I saw this one(

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Motorola - Milestone XT720 Mobile Phone (Unlocked

but not sure if it will work, I asked best buy employe at the store they said not sure but that they would allow the phone to be returned.

[Entropy]

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jpf0525 wrote:

I am interested in purchasing a unlocked phone but know there are differences in cdma and gsm. I'm i...or any motorola android phone really. To be used with Boost Mobile, any suggestions?

---

CDMA (specifically cdmaOne/CDMA2000) - This is the system used by Verizon and Sprint's networks.  These devices do not have a SIM (with a few certain exceptions) and the device, even if technically "unlocked" (Verizon never locks the programming mode of the phone, password is almost always 0000), they can't be used on any other network because Sprint and Verizon will not activate a device that they didn't sell.  Your account is tied to the phone's serial number.

GSM (which actually includes GSM and UMTS nowadays, but most people just refer to it as "GSM") is the system used by AT&T and T-Mobile.  These devices all use a SIM, and your account is tied to your SIM and not the phone's serial number.  So you can swap your SIM to another phone and it will work if the phone is unlocked.  HOWEVER:  In addition to network locking, various networks use different frequency bands, and an unlocked phone that doesn't support the right bands won't work.  This usually means:

Any phone sold by AT&T will only get 2G service on T-Mobile, not 3G (Except for the Samsung Skyrocket, and to get this to work requires some very specific technical hacks.)

Some phones sold by T-Mobile will get 3G service on AT&T, but not many

A reasonable number of internationally sold phones get 3G service on AT&T but not T-Mobile (such as the international Galaxy S II and Galaxy Note)

Only one internationally sold phone I know of gets 3G service on both AT&T and T-Mobile - the GSM Galaxy Nexus

[Entropy]

Boost is a Sprint reseller, so their network is CDMA.  You cannot use unlocked GSM phones on this network.