Database Users

[Q] Samsung Galaxy S i9000 user coming to US. What are the options to get data plan

I know this is not a tmobile forum, but then you Vibrant guys are like my real brothers since I use a i9000 Galaxy S with 3g in my part of the world.
I know that 3g for me is out of question due to different bands. I did my homework on that, but then what about Edge data connection atleast. As i studied the tmobile site, it looks like getting Edge connection (unlimited) is also difficult just because I dont have a credit history in US so cant get those EM or EM+ plans i guess.
I have come in and out of US many many times but was always on prepaid tmobile sims and never really wanted data as such. But with an android phone and using 3g for many months, I just dont think i can live without data connection. I know about flexpay and thats what I used last time. But now on tmobile prepaid section i dont see flexpay at all. I see Even More (not for me due to contract) and Even More + which is without contract - but I guess it still needs a credit check?? Also they will force me to buy a vibrant i guess for EM+ plan which I cant since I have my shinny i9000 with me .
So please brothers, any suggestions that you can give. I have lots of experience with tmobile reps and they just dont know much, many a times (my opinion). Hence wanted to ask here.
So summarizing:
I come with work visa with valid SS, pay taxes and all that, and no credit history. (<- is that bad??). How can I get an unlimited data plan with my talk plan. EM+ ? Flexpay ? (not sure if its still there).
The plan that I have in mind was : 500 Minutes Talk + Unlimited Text + Unlimited Web: 59.99$ EM+ but without creditcheck so I guess thats FlexPay.
Googling around, I saw EM+ flexpay pages of tmobile website but they are not selectable or show up in normal plan selection at all.
Looking forward for help.
I promise that if you ever come to my part of world, I will work with you to keep your data connection ON on your Vibrant. I will not be able to give you "H" but surely an "E"
Thanks guys in advance.

Actually, 3G worked for me on [email protected] with the international Galaxy S. The speeds were comparable with what I was getting on my old iPhone in HSDPA mode. The download speeds were better than what I am getting on T-Mobile in my area.
Not sure if AT&T let's you buy monthly plans though.

When I was in the UK a year ago with my G1, I believe I was able to get onto T-Mobile's 3G with no issue using a pre-paid UK T-Mobile sim. You may want to try to use T-Mo and AT&T pre-pay sims first and see what you can get and who is faster in your area before you get a plan. AT&T has better nationwide coverage and generally faster 3G speeds, but if you live in an area where T-Mobile has updated their towers to HSPA+, then they'll be the faster carrier for GSM phones.

Go with MySimpleMobile (http://mysimplemobile.com). They are a prepaid service with no contracts: $60 unlimited talk/text/web per month. They use T-Mobile's network so you will get 3G.
Oh and they allow for unlimited international texts at no extra charge; this may be useful for you since you are coming from overseas and will probably have friends and family you want to text.

DarkAgent said:
Go with MySimpleMobile (http://mysimplemobile.com). They are a prepaid service with no contracts: $60 unlimited talk/text/web per month. They use T-Mobile's network so you will get 3G.
Oh and they allow for unlimited international texts at no extra charge; this may be useful for you since you are coming from overseas and will probably have friends and family you want to text.
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Thanks a lot DarkAgent. Looks like this was custom made for me international texting is good but mostly wont be using it if I have unlimited web since I can hop on to gtalk and take it from there. But nice service though. Thanks for the information.
Not sure about 3G since they have mentioned that your phone shoudl support 1700mhz band to be able to use 3g. So there goes my 3g I guess since I have 900/1900/2100 bands UMTS. But edge is still okay, though I will have to find another way to do VOIP.

DarkAgent said:
Go with MySimpleMobile (http://mysimplemobile.com). They are a prepaid service with no contracts: $60 unlimited talk/text/web per month. They use T-Mobile's network so you will get 3G.
...
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Nope, with the international Galaxy you will not get 3G on T-Mobile's network, only on AT&T's.
You will get edge, although it is pretty painful, IMO.
But there is WiFi in a lot of places -- check your mail in most coffee shops for free

Oh. I wasnt aware the int version didnt support tmo 3G

Oh well, I am here now. Just wanted to share.
Mysimplemobile isn't that good. They don't do unlimited so much as they advertise.
Just went to Tmobile and did their even more plus plan with flexipay. They don't show flexpay on website but they very much have it.
You can avoid the control charge if you give the card on file.
I am one happy camper.
Sent from my GT-I9000 using XDA App

USA sim

I am from Israel and I am coming to the States on the next Monday. I need a sim with unlimited data, and about 100 minutes of talk and some messages.. I also need wifi tethring option to tether my tablet and laptop. I cant decide which carrier to choose. T mobile daily plan sounds nice but there are others like h2o, net10... Any suggestions?
Sent from my GT-P7510 using Tapatalk 2

I would get the T-Mobile $30 unlimited data and texting with 100 minutes. The $3 a day plan is also a good option if you're going to use under 200MB a day.
All the plans AT&T MVNO's(H2o, Red Pocket, etc) have low data allowances and cost more than T-Mobile.
AT&T has 250 minutes and unlimited texting for $25 a month. You can add data for $25 a GB.

bar_rodoy said:
I am from Israel and I am coming to the States on the next Monday. I need a sim with unlimited data, and about 100 minutes of talk and some messages.. I also need wifi tethring option to tether my tablet and laptop. I cant decide which carrier to choose. T mobile daily plan sounds nice but there are others like h2o, net10... Any suggestions?
Sent from my GT-P7510 using Tapatalk 2
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You should make sure your phone supports the AWS band (also known as band IV) for 3G before going on T-Mobile or band II or V for AT&T 3G.
T-Mobile checks UA string to detect tethering, so you will need to spoof it in your browser settings to get around it. Not sure about AT&T or any MVNO, however.
Would strongly suggest T-Mobile if your phone supports it and you plan to stay in a metro area. Otherwise, go with an AT&T MVNO.

While I have not had any experience with T-Mobile, all of my past experience with AT&T has been horrid. I would not recommend them for prepaid or postpaid usage

Rikairchy said:
While I have not had any experience with T-Mobile, all of my past experience with AT&T has been horrid. I would not recommend them for prepaid or postpaid usage
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As much as I would agree (I hate calling people who I know are on AT&T because the calls drop frequently), T-Mobile's 3G coverage is much smaller than AT&T's 3G coverage - leaving AT&T as the only GSM option in some areas. That said, if you spend most of your time in or around major cities, T-Mobile is superior both on performance and price.

I have LG P500, it has quad band and tri band.. should it work with T Mobile? I will be in major cities like NYC, Philly, DC...

bar_rodoy said:
I have LG P500, it has quad band and tri band.. should it work with T Mobile? I will be in major cities like NYC, Philly, DC...
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You won't be able to get 3G from any US carrier with that phone. It supports 900 / 2100 for 3G and none of the networks over here support those 3G frequencies.
You'll be on 2G no matter which carrier you choose.
Sent from my SGH-T989 using Tapatalk 2

Mr.Mischief said:
You won't be able to get 3G from any US carrier with that phone. It supports 900 / 2100 for 3G and none of the networks over here support those 3G frequencies.
You'll be on 2G no matter which carrier you choose.
Sent from my SGH-T989 using Tapatalk 2
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From what I know, T mobile uses 2100 MHZ...
By the way, how about Motorola Milestone 2?

bar_rodoy said:
From what I know, T mobile uses 2100 MHZ...
By the way, how about Motorola Milestone 2?
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Nope. T-Mobile uses 1700/2100 together. You can't just use 2100 on T-Mobile.
The international Milestone has the same bands as your P500. The US Milestone supports AT&T 3G.
Sent from my SGH-T989 using Tapatalk 2

Mr.Mischief said:
I would get the T-Mobile $30 unlimited data and texting with 100 minutes. The $3 a day plan is also a good option if you're going to use under 200MB a day.
All the plans AT&T MVNO's(H2o, Red Pocket, etc) have low data allowances and cost more than T-Mobile.
AT&T has 250 minutes and unlimited texting for $25 a month. You can add data for $25 a GB.
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The problem with the T-Mobile $30 unlimited data (up to 5Gb) plan is you won't be able to use any data on Edge and they don't really have 4G anywhere unless your phone does WCDMA on 1700Mhz then it will work at T-Mobile stores but that's all. You will need a newer Samsung Galaxy S2 or S3 phone to take advantage of 3G service on T-Mobile.

stevec5000 said:
The problem with the T-Mobile $30 unlimited data (up to 5Gb) plan is you won't be able to use any data on Edge and they don't really have 4G anywhere unless your phone does WCDMA on 1700Mhz then it will work at T-Mobile stores but that's all. You will need a newer Samsung Galaxy S2 or S3 phone to take advantage of 3G service on T-Mobile.
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When the OP made the thread and mentioned T-Mobile, I figured he had a T-Mobile compatible phone. If you reqd the post above, you'd see I pointed out that T-Mobile 3G/4G wouldn't work on his phone.
But, don't have to be at a T-Mobile store to get 4G. That's absurd. Also, there's no need for a new T-Mobile phone to get fast data, any T-Mobile 3G phone will work.
Sent from my Galaxy Nexus using Tapatalk 2

Mr.Mischief said:
When the OP made the thread and mentioned T-Mobile, I figured he had a T-Mobile compatible phone. If you reqd the post above, you'd see I pointed out that T-Mobile 3G/4G wouldn't work on his phone.
But, don't have to be at a T-Mobile store to get 4G. That's absurd. Also, there's no need for a new T-Mobile phone to get fast data, any T-Mobile 3G phone will work.
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I disagree, it may sound absurd until you realize they don't really have any 4G network anyplace but they need service inside the stores so they can display the phones working. In the Phoenix, Mesa and Scottsdale areas the only place you can get 4G on T-Mobil is in or near the T-Mobil stores where they have a 5 bar signal. They claim they aren't using an amp or anything but if you leave the store and go down the street a few blocks there's no signal and it's not available anywhere else.
As for saying "any T-Mobile 3G phone will work" you know they haven't sold 3G phones since 2010, right? None of the new Samsung 4G phones can get 3G either, at least none of the ones I looked at in the store could get it since they don't have an option for HSPA or HSPA+, just GSM and WCDMA with nothing in between.

stevec5000 said:
I disagree, it may sound absurd until you realize they don't really have any 4G network anyplace but they need service inside the stores so they can display the phones working. In the Phoenix, Mesa and Scottsdale areas the only place you can get 4G on T-Mobil is in or near the T-Mobil stores where they have a 5 bar signal. They claim they aren't using an amp or anything but if you leave the store and go down the street a few blocks there's no signal and it's not available anywhere else.
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Tinfoil hat much? Nuff said.
I get T-Mobile 4G all over Alabama, miles away from the T-Mobile store. I also travel yearly to TN, LA, MI, and GA, and I get T-Mobile 4G in those states as well.
stevec5000 said:
As for saying "any T-Mobile 3G phone will work" you know they haven't sold 3G phones since 2010, right? None of the new Samsung 4G phones can get 3G either, at least none of the ones I looked at in the store could get it since they don't have an option for HSPA or HSPA+, just GSM and WCDMA with nothing in between.
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All T-Mobile smartphones phones are capable of 3G. You confusing T-Mobile 4G with LTE. T-Mobile doesn't have LTE, and their 4G network is nothing more than fast 3G. The icon in the corner of your screen might only show 4G, but there are many instances where it's actually getting 3G I get 3G with my Galaxy Nexus on T-Mobile.
You really need to do some serious research.

Lets try and keep this on topic of the thread bout sim card and not go off about how good the actual networks are etc.

The fact of the matter is, you'll only get 3G/4G (HSPA+) on AT&T and AT&T MNVO's. If OP needs fast data, I'd recommend a Straight Talk AT&T-Compatible SIM from http://straighttalk.com. It's $50 for a month of unlimited everything (just don't go too crazy with data). When you fill in the APN, ignore any proxy fields except for "MMS Proxy".

Product F(RED) said:
The fact of the matter is, you'll only get 3G/4G (HSPA+) on AT&T and AT&T MNVO's. If OP needs fast data, I'd recommend a Straight Talk AT&T-Compatible SIM from http://straighttalk.com. It's $50 for a month of unlimited everything (just don't go too crazy with data). When you fill in the APN, ignore any proxy fields except for "MMS Proxy".
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His phone runs on 900MHz and 2100MHz, doesn't AT&T 3G run on 850MHz and 1900MHz?

Oh wow, he has some funky frequencies. He'll need a different phone for 3G/4G on any network then. Basic functions and EDGE should work though.

Moving from Europe to USA

Hi guys,
I will be moving to the US (Chicago) next month and I have a few questions for my good Defy friends:
- Will I be able to use my unlocked Defy in the US with 3G speeds and/or HSDPA speeds?
- Is there a carrier that will let me use my phone and give me cheaper prices?
- For new voice+data plans, can I get unlimited for cheap somewhere with good coverage?
- What baseband and GPS settings should I use there?
I'm from Serbia/Europe, and I'm using my Defy with standard Central Europe baseband now and europe gps fix.
I looked around some carriers in US and I think maybe Sprint has some unlimited data plans? Could I use my Defy on their network?
Any help will be appreciated!
Cheers.

I dont see any reason why it would not work, just use correct baseband
E: also im not from usa, so i dont know about us carrier plans but as long as it is unlocked, it should work fine on Sprint network
Sent from my MB525 using xda app-developers app

hsrars-d said:
I dont see any reason why it would not work, just use correct baseband
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Oh really? But which baseband to use in Baseband selection settings in CM7.2 if I want to use Sprint or Verizon or AT&T network?
There is only baseband for TMobile, but 2 or 3 of them though.

from what i know, you will need to use a GSM based operator, some operators in the USA use a system called CDMA, also your speeds may be slow to very slow on T-mobiles USA system as they use a wierd system for data, one frequency for uploads and another for downloads thats not used anywhere else.
Anotheir thing thats worth taking note of is that some US networks charge for incoming calls and texts ( or take incoming calls and texts form your alowance of minutes and texts/sms)
So you need to find an operator that uses a GSM system
you need to have your phone unlocked to work with any sim card
and you should try and find a service that deosnt charge for incoming calls and texts ( or that doesnt take these from your inclusive minutes/texts)

Proda said:
I'm from Serbia/Europe, and I'm using my Defy with standard Central Europe baseband now and europe gps fix.
I looked around some carriers in US and I think maybe Sprint has some unlimited data plans? Could I use my Defy on their network?
Click to expand...
Click to collapse
If your phone is rooted (and since you're on xda I'm sure it is) install baseband switcher and download the baseband you need.
Sprint and Verizon use CDMA, so your Defy won't work with them.
T-Mobile and AT&T use GSM.
Your european Defy uses 900 and 2100 MHz for 3G. AT&T uses 850 and 1900 MHz, so you'll be stuck with their slow EDGE network.
T-Mobile uses 1700 and 2100 MHz for 3G. Their 2100 MHz band is compatible with your Defy.
If you want to use 3G on your european Defy then T-Mob is your only option.
An american contract without phone costs almost as much as a contract with a subsidized phone, so you may as well get a phone with american 3G/4G frequencies. Contractless options are ridiculously expensive with all sorts of stupidity such as "daily access fees." Prepaid texts and minutes usually have draconian expiration policies. Some carriers make you register your phones with them, and they only accept phones from a list of "approved phones." From a european point of view, american cell phone service and pricing is a mess.

Yes, my phone is rooted (the 1st day I bought it I rooted it and installed custom ROM ), and it's sim free (unlocked).
And I'm using CM7 so I have preinstalled baseband switcher.
In baseband switcher, when I go to America I have only T-mobile bands: T-mobile 3.4.2-107-9, 3.4.2-107-4 and 6.xx.0.
Which one is the best to use?
Yes I saw that it is a quite a mess with cell phone services in US. It's pretty expensive too (for plans that I have in Serbia). And one have to read all the tinny little words at the end of page (you have to pay for INCOMING SMS/MMS, or for INCOMING calls, and some stupid stuff like that)
So you suggest that I just take full pack - plan+mobile device? I saw that Verizon has the best 4G network in US. Maybe take that? Or you suggest something else? (I would like to have around 1gb of Data per month - that is UNLIMITED Data for me, and possibly free SMS and at least 300min of calls. And of course not to pay that too much - I saw some UNLIMITED Data plan in Sprint, but it is around 80$/month or more).
Now I pay 10$/month for plan that has 600mb/300minCalls/600sms.
Thanks for info one more time.
Cheers.

They will rip you off for 4G data plans. As i saw (out of curiostiy), expensive as hell.
The best way is to relax a bit and once you arrive there figure out the best solution for you and your family. It's simplier to go the brick and mortar store and discuss then to speculate here. They have some family packages that may be good.
And yes it will be better to buy a new phone with contract there. You might as well sell this Defy in Serbia. "leave old things in the past"

When you buy an american phone, Google your unlock options first. When you're back in Serbia for holidays you'll probably want to use your shiny new phone with a serbian SIM card.
Where I live carriers only lock phones on prepaid plans, but american carriers have the annoying habit of locking all their phones, even if you buy them on a two year contract.

rogier666 said:
When you buy an american phone, Google your unlock options first. When you're back in Serbia for holidays you'll probably want to use your shiny new phone with a serbian SIM card.
Where I live carriers only lock phones on prepaid plans, but american carriers have the annoying habit of locking all their phones, even if you buy them on a two year contract.
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Click to collapse
And Verizon is Simless as i know.

I assume you're in the US by now. Have you chosen what to do? I have a US Tmobile defy, and use tmobile prepaid service. 2gb at 4g (3g for defy) speeds then unlimited data at Edge speed is $60/month. that includes unlimited talk and txt.
I don't know which baseband is better either. I'm on 3.4.2-107-4 and haven't had any problems. I've also wondered which is better. I've thought maybe 107-4 is 2g and 107-9 is 3g? and when you switch on 2g/3g it switches itself? I really don't know though.

I wish I'm in the US now. But it seems that employers forgot about all the paperwork required to obtain working visa for US :silly:, so imo I'll be in the US around 1st of January 2013.
Then I can try to answer your questions
But I think I will buy Nexus 4 as soon as I get my 1st paycheck. :fingers-crossed:
I would prefer GSM phone so I could be able to use it when I come to Serbia on vacations. (I heard that iPhone 5 on Verizon is SIM card FREE so it is possible to use it with any GSM carrier But that is IPHONE. Who needs that! )
I still don't know which carrier I will chose. I saw one that looks nice and it is prepaid, maybe it has postpaid too (RedPocket)
I will be mostly in Chicago and Boston, so I think this carrier would be OK.
Or maybe T-mobile...
But before I buy new phone I'll have to choose SIM card to use it on my good old Defy. If you say T-mobile works for you, then I'll get that one (or this RedPocket if I find it somewhere).

HI!
I have a similar problem. I moved to the US (Chicago) for a few months. I have a defy with cm10 installed. Up to date at this point.
I bought a t-mobile prepaid simcard. I get only edge speed. According to what I read, T-mobile uses 1700MHz and 2100 MHz for the 3G. Actually both are required!
When I select baseband there are the three options for t-mob, but none of them work (at the details of the options, both 1700 and 2100 are mentioned). I also tried defy baseband switcher.
Is it even possible to use 3G on T-mobile with this phone? If yes, how?
Thanks!

Straight talk with att phone

Sorry first time trying a phone other then cdma. If i get the galaxy note 2 on att when it comes out and order a straight talk sim can i just slip it into the att galaxy note 2 and have hspa+ working. I want to try straight talk first because i here good and bad stories and if it sucks i can just cancel my contract within 14 days for att. Atleast so i can try out the note 2 to see if i like it. Once again i never had a sim card phone so im kinda clueless if i can swap them freely for tmobile and att phones or if i have to get an unlocked international version.

If you buy an AT& T phone, it will indeed work with an AT& T SIM card from ST (without being unlocked).
However, if I read your post correctly, you're going to get the phone on (an) AT& T subsidized (plan) then put a ST SIM in it? You DO realize that you will then have to pay AT& T a monthly fee and still pay ST their fee (even is it's month to month without a contract)....that makes no sense. You're paying an extra 45$ a month that you don't have to, on top of AT& T' s monthly fees....
Snowflake approved this message....

Lol i know im just wanted to get the note 2 to try and try out straight talks sim for att and see within 14 days if they cancel or slow my speeds like i hear so many people say. I guess i could just buy the phone at att without a contract to right? And use it for 14 days to see if i like it and return it if i dont

al52025 said:
Lol i know im just wanted to get the note 2 to try and try out straight talks sim for att and see within 14 days if they cancel or slow my speeds like i hear so many people say. I guess i could just buy the phone at att without a contract to right? And use it for 14 days to see if i like it and return it if i dont
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Yes. It really depends on your area and how you set the APN (with or without proxy), that dictates speed. (Mostly area). ST on the AT&T side is pretty strict on data USAGE though. Most have found that staying under a 100MB per day/2GB per month is acceptable. Any more and you can not only be throttled but, they can (and will) shut off your service without notice or refund.
That being said, if your are aware of the cons to ST, many have found that the service works well for them and they are extremely happy with the price.
If you live in an area that T-Mobile has refarmed their 1900mHz band to HSPA+ you can get a T-Mobile ST (and use it on "4G") (or a T-Mobile SIM, prepaid or otherwise) and use that phone (unlocked only of course) that way. Some have found the T-Mobile side of ST to be more lenient with data usage policies.
If you don't talk much (and your area has been refarmed and your phone unlocked) the 30$ plan (only available at Wal-Mart or on T-Mobile.com) with 100 minutes, unlimited texts and 5GB data is a another option.
Snowflake approved this message....

Babydoll25 said:
Yes. It really depends on your area and how you set the APN (with or without proxy), that dictates speed. (Mostly area). ST on the AT&T side is pretty strict on data USAGE though. Most have found that staying under a 100MB per day/2GB per month is acceptable. Any more and you can not only be throttled but, they can (and will) shut off your service without notice or refund.
That being said, if your are aware of the cons to ST, many have found that the service works well for them and they are extremely happy with the price.
If you live in an area that T-Mobile has refarmed their 1900mHz band to HSPA+ you can get a T-Mobile ST (and use it on "4G") (or a T-Mobile SIM, prepaid or otherwise) and use that phone (unlocked only of course) that way. Some have found the T-Mobile side of ST to be more lenient with data usage policies.
If you don't talk much (and your area has been refarmed and your phone unlocked) the 30$ plan (only available at Wal-Mart or on T-Mobile.com) with 100 minutes, unlimited texts and 5GB data is a another option.
Snowflake approved this message....
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Good info here. To add to it, you can check for your area being refarmed if it has T-Mobile 3g on your network scan. Or you can check airportal.de where users have reported the refarm.
Sent from my XT883 using xda app-developers app

[Q] Verizon service/plans when it comes to phablets

I have a phone that I bought from Verizon and I have kept the unlimited data. I know all about my phone but next to nothing about my service.
My question is specifically about phablets (for example, this) which is basically a big ass phone, or a tablet with cell service, however you want to word it. I'd use it exclusively with bluetooth instead of holding the thing up to my head, don't worry.
I travel internationally and see them A LOT in other countries (they cannot help me though since I need one to use in the US). I am under the impression that VZ will not activate anything I did not buy from them. I don't know how solid this is but every VZ employee I have asked has confirmed this so far. I know in the past that it used to be as simple as switching out the SIM card but doubt this is still the case.
I'm sure there are some hardware specs (frequencies?) that I need to look at that would determine the LTE/4G/3G whatever compatibility, but I don't know the terminology. Also I'm not exactly sure what I'm looking at when it comes to CDMA vs GSM, only that blokes in England use GSM. Can you help me out?
Also, I am hesitant to leave VZ because of the unlimited data and the service coverage. I live in mildly populated CT, USA and would welcome a prepaid plan if data/service is comparable but don't even know where to begin looking.
Thank you in advance - I really don't have anyone else to ask about this stuff.

I'll try to make it simple for you. There are really two types of cell networks (not counting LTE, since all carriers are using that now here in the US): GSM and CDMA.
CDMA is what Verizon, Sprint, US Cellular, MetroPCS, Cricket, and maybe other smaller carriers use. It is based on a serial number called a ESN on older phones or MEID on newer phones (since the late 2000s). That serial number is burned into the programming of the phone on the ROM and cannot be changed very easily and is illegal to do so supposedly. There are two types of CDMA technology in use today, 1xRTT and EVDO (older analog was phased out a few years ago). 1xRTT or 1x as it's abbreviated, is a "2G" technology that allows for packet switched voice and SMS traffic, as well as very very slow data speeds (think 56k dialup). EVDO is strictly for data (the voice part was never added because they didn't want to pony up the cost of it) and is used in Rev 0 and Rev A EVDO. Most Verizon/Sprint 3G is Rev. A EVDO. It hits a max of 3.1Mbps down and if you get a call or text message, it drops to 1x and the 3g is suspended, unless you have a radio that can do both at once (HTC Thunderbolt). You activate by serial number and a bad ESN means they didn't pay their bill or it was an insurance claim on a lost phone and they are blacklisted.
GSM is a technology essentially where it uses a little plastic and electronic card called a SIM card. T-Mobile and AT&T are the two major carriers with this technology. There are several revisions of this technology in use today, GRPS, Edge, and various UTMS and HSPA versions. GRPS is analogous to 1xRTT in terms of speed, and Edge is in between and gives up to 250kb/s down, technically a 3g technology, although not feeling like it. UTMS, HSPA, and WCDMA all refer to a similar type of technology which is what is used by the 3G level of service of AT&T and T-Mobile (fake 4G on T-Mobile). It goes from just faster than Edge to DC-HSPA 42Mbps down speeds and allows for simultaneous voice/data (Edge and GRPS are either data or voice, not both). Your phone number is tied to the SIM card and this technology offers an advantage of if your main phone craps out, you can store your contacts on the SIM and just put it in another phone and still have service.
Roaming and tower authentication are completely different in GSM vs. CDMA. CDMA uses what's called a PRL (Preferred Roaming List) to determine which towers to authenticate to essentially, and sets priority. Some people will "hack" the PRL by changing it so for example if they have Sprint and their tower has the crappy 3g speeds, they roam on Verizon since they have unlimited roaming and get Verizon's better 3g speeds. GSM roaming is set per tower or location on the SIM card, and is a pretty static value dependent on the carrier. Roaming is only if they allow it depending on your plan and location (like T-Mobile prepaid will not roam on AT&T, but postpaid "Uncarrier" plans will).
So what you have is probably a tablet based on the data that gets EVDO service and probably 1xRTT and maybe LTE. If you have it on a phone plan and not a tablet plan, it's probably a Note 2 or something which is just really a phone from what it sounds like if you use Bluetooth. CDMA carriers will only use their devices and lock down ESNs to what they sell, so you can't buy a device from Sprint and put it on Verizon. The exception to that is sometimes prepaid carriers will let you "flash" the phone to their service but don't guarantee the results and don't support it. Examples include Cricket, MetroPCS, Page Plus, and I think Virgin Mobile or Boost *might*, but don't quote me.
LTE is a newer technology which isn't technically 4G yet since we haven't seen speeds here in the US on current LTE revisions of over 100Mbps, but they do have the ability with the right equipment. It uses SIM cards so you will see newer Verizon/Sprint devices actually use SIM cards for service (which is superior as noted above), and have an ESN so it can fall back to 1x or EV. The plan is to eventually roll out LTE to all towers and if you have a LTE device, you use LTE for voice and data (VoLTE), but all carriers don't have LTE on all towers so they fall back to HSPA/Edge or 1x for voice for now. They probably have dual radios like the HTC Thunderbolt and use both at the same time but LTE is still a maturing technology and has a lot of potential.
I hope this helps.
Edit: I forgot to add, for the smaller prepaid plans, you have to look at who they are based off of. Most of them just use a parent network from one of the 4 big carriers (Cricket being the exception, they have their own towers and roam on Sprint if you leave native coverage). I know Page Plus uses prepaid Verizon towers, but for the most part you won't get unlimited uncapped data on Verizon unless you keep your old $30 grandfathered plan. If you switch to a limited data plan, say bye bye. Honestly if you don't want to pay Verizon prices (I don't blame you), and you have the availability for it for coverage, T-Mobile or Sprint have good options. T-Mobile's network where they have 3g/4g is way way good. They just deployed equipment on their towers that's above everyone else with new NSN antennas and the LTE revision is LTE-A I think (check what Milan posted on Howard Forums for sure), but it's high dollar equipment that isn't cheap. Also they are upgrading the backhaul on their towers and most people are pulling between 10-20Mbps on DC-HSPA and 15-30Mbps on LTE. Milan got about 25 Mbps in NYC on T-Mobile LTE so they are a really good way to go and you can get an unlimited plan for $70 a month prepaid. Also, you can get a 5GB/100 min/unlimited SMS plan for $30 from Wal-Mart/tmobile.com.