can the evo shift be used for boost mobile?
Yes it is possible; however you may need to do extensive work and also buy software like the CDMA Workshop in order to program the correct NAM settings. You will need to get the MLS and carrier info too. Let's just say it will be near impossible unless you already own an Android based boost mobile phone. It is not as easy as GSM where you can just carrier unlock the phone and pop in a new SIM card. I have done it successfully for a friend but the work involved was not fun at all. However boost is a lot cheaper on a monthly basis so it's all a question of time, money and skill.
There are people on craigslist in my area that say they can do it so I'm sure its possible.
Sent From My Speedy Mc Speederson
It would involve cloning an ESN from an existing Boost Mobile phone. Not something often discussed on XDA and frowned upon.
Can't you just buy a cheapy phone and use the esn? That may be illegal though I'm guessing.
Do the boost phones use the same Sprint towers?
Sent From My Speedy Mc Speederson
Boost Mobile Networks
The CDMA Boost Mobile wireless handsets only work on Sprint's PCS spectrum while the iDEN ones only work on Sprint's 850 MHz iDEN network. The two types of Boost Mobile handsets are not interoperatible with the other's spectrum. Sprint does not have any roaming partnerships will other wireless carriers which use either CDMA or iDEN. Once Sprint's Network One initiative to eventually convert the 850 MHz iDEN to CDMA is completed (around 2013), the CDMA Boost Mobile subscribers will have a larger footprint of coverage.
So when my shift starts roaming, whose network does it roam on in philly? ANy idea. I think Verizon is the only one here that uses CDMA network.
coosawatchie said:
So when my shift starts roaming, whose network does it roam on in philly? ANy idea. I think Verizon is the only one here that uses CDMA network.
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Pretty sure thats what you would be roaming on (Verizon)... Though I'm guessing that wouldnt be the case on Boost as roaming is supposedly not allowed.
http://forum.xda-developers.com/showthread.php?t=1038116
For customers who use the HTC EVO Shift 4G on a postpaid service with Sprint, off network CDMA roaming may be on Cricket Wireless, MetroPCS as well as Verizon Wireless since all 3 wireless carriers have a CDMA footprint in Philadelphia. Because of confidential and proprietary roaming partnership agreements, wireless carriers can't legally disclose who are the particular roaming carriers they partner with in a given market.
Related
Is this possible? I went into a Sprint store and they told me that it was against store policy to do that.
I really like this phone but I hate Cingular service it has to be the worst possible out there.
I appreciate any and all answers.
thanks in advance!
I beleive they are two different types.. Cingular is GSM .. I forget what sprint is.. but it's not GSM
nope wont work att is gsm sprint is cdma
so I guess I need to go back to cingular to still use this phone? Any others carriers I can use it on that may be worth my time?
Sprint uses CDMA, which is an old, OLD OOOOLLLLDDDD technology.
Sprint invested a lot in building the CDMA network in North America so they seem reluctant to abandon it, even if it is an inferior network infrastructure in nearly every measurable way.
With almost all other carriers, it is possible to unlock phones, swap SIM cards, etc., to change providers. With Sprint, it's not possible.
You could move to T-Mobile service easily. I'm not sure about Verizon.
Doom Tints said:
Sprint uses CDMA, which is an old, OLD OOOOLLLLDDDD technology.
Sprint invested a lot in building the CDMA network in North America so they seem reluctant to abandon it, even if it is an inferior network infrastructure in nearly every measurable way.
With almost all other carriers, it is possible to unlock phones, swap SIM cards, etc., to change providers. With Sprint, it's not possible.
You could move to T-Mobile service easily. I'm not sure about Verizon.
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Click to collapse
Very true. T-Mobile and AT&T are the only major GSM carriers in the USA. Verizon, like Sprint is CDMA.
American Networks
Cingular/AT&T = GSM
T-Mobile = GSM
Sprint+nextel = CDMA/TDMA
Verizon = CDMA
US Cellular = CDMA
Thats all I know, i will keep digging
Here's a list of current and future GSM carriers in the USA, most of which I've never heard of:
http://www.gsmworld.com/roaming/gsminfo/cou_us.shtml
So another big-ish player who uses GSM would be Alltel.
Here's a list of CDMA carriers, if interested:
http://www.rentcell.com/cdma-info.htm
um... alltel is most deff CDMA and dobson cellular systems (which at&t just bought) also uses GSM..
revol wireless is cdma
northcoast pcs is cdma also
No, this website is correct about Alltel. If you look at its GSM coverage map, their GSM coverage is a bit limited. It's just not GSM where you are.
I don't know about the others you mentioned, or care.
so do alltel phones run dual then? cdma/gsm? cuz ive NEVER seen a gsm alltel phone at the store.. unless that area you mentioned has special phones
dbroncos38 said:
Is this possible? I went into a Sprint store and they told me that it was against store policy to do that.
I really like this phone but I hate Cingular service it has to be the worst possible out there.
I appreciate any and all answers.
thanks in advance!
Click to expand...
Click to collapse
BEST POST EVER!
hahahahahahahahaha
Altell mainly uses CDMA in the US and only uses GSM for roaming partner revenue. CDMA is not old oudated technology either ATT/Cingular is using WCDMA now which is slightly different.
Sprint does have an equivalent to the 8525. It was the MDA and now it's the prophet I think - you may want to double check that. You should be able to ebay your 8525 for about as much as an ebay prophet will cost you.
hi
The prophet is also a GSM phone
as much as everyone hates at&t, i've had them for 10 years. Lately, the customer service has been much better, and I have never had a problem with service in my area. I would look over at my girlfriend's phone, which is T-Mobile, and then look over at my 8525, and when I had full service with at&t, she either had none or barely one bar. at&t is apparently spending $18 MIL a day putting up 70 new towers a week to expand not only the regular network, but the 3g network. also, if you go with t-mobile (correct me if i am wrong) but you won't get umts/hspda. good luck with your choice.
-Nstefanelli-
gthing said:
Sprint does have an equivalent to the 8525. It was the MDA and now it's the prophet I think - you may want to double check that. You should be able to ebay your 8525 for about as much as an ebay prophet will cost you.
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Sprint has the PPC6800 and, VZW is rumored to soon have the XV6800. Both are the same phones that are labeled for each carrier. It is the HTC Mogul (TyTN with WM6 and slightly smaller).
As for which network strategy is better, that has become quite a religious war because there is not much different anymore. CDMA always had the technical advantage, but now with WCDMA, there is much more parity.
As for which one is older, GSM was there before CDMA. To me, the key benefit to GSM based networks is that they can be used almost anywhere (given the right radio frequencies in the phone). CDMA is limited.
Doom Tints said:
No, this website is correct about Alltel. If you look at its GSM coverage map, their GSM coverage is a bit limited. It's just not GSM where you are.
I don't know about the others you mentioned, or care.
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Click to collapse
Yes it is true that Alltel "owns" GSM, but that is because in 2005 they purchased a company called Western Wireless. They still run as two seperate companies. Alltel runs their network based completely on CDMA and has roaming agreements with Sprint and Verizon.
Here is a map for you: http://www.mountainwireless.com/Alltel_ww.jpg
Deadem said:
Altell mainly uses CDMA in the US and only uses GSM for roaming partner revenue. CDMA is not old oudated technology either ATT/Cingular is using WCDMA now which is slightly different.
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ATT only have CDMA back then..then they upgraded their network to GSM and phase out the CDMA network to better compete with Cingular and T-mobile. Now with the merger between ATT and Cingular, they only have GSM networks. The new WCDMA is planned to boost its 3G speed.
It boils down to this: GSM is the worldwide standard for cellular phone communication, except in the U.S. If you never plan on travelling outside the U.S. then the CDMA technology is fine for you (Sprint, Verizon). If you ever think you may want to travel ANYWHERE outside the U.S. and take your phone with you for quick and easy communication, and maybe even data link, then consider GSM. In the U.S. that would be ATT/Cingular, T-Mobile (there may be a few new smaller outfits as well). ATT/Cingular leads the pack in 3G/HSDPA (cellular broadband) coverage.
Service seems to depend on who, at the present time, is #1 in subscribers and who is trying to BECOME #1. I originally had Verizon until my travels took me overseas frequently. Verizon's customer svc had started to fall off as far as I was concerned. My experience with ATT/Cingular's cust svc gets them a rating of 'Fair'--nothing spectacular, but I don't use cust svc very often and their signals are the best around.
I have an Evo and I really want the tunderbolt. If I can somehow "put" it on sprint can I still use 3g? Do they use the same bands is what I'm asking.
Yes, they do. I used to have a fully functioning Sprint touch pro operating on Verizons network. But good luck getting either carrier to activate the others phones. I know Verizon closed that loophole years ago.
kdj67f said:
Yes, they do. I used to have a fully functioning Sprint touch pro operating on Verizons network. But good luck getting either carrier to activate the others phones. I know Verizon closed that loophole years ago.
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ESN transplant
Halabeaster54 said:
I have an Evo and I really want the tunderbolt. If I can somehow "put" it on sprint can I still use 3g? Do they use the same bands is what I'm asking.
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Click to collapse
As it was said, the MEID / ESN could theoretically (and illegally lol) be modified to emulate a separate device. The phones themselves have very similar hardware in the fact that they can operate on either network. The 3G chipset includes two bands -
the 800MHz 'Cellular Band' which is preferred by Verizon, and
the 1900MHz 'PCS Band' which is preferred by Sprint.
It operates as a standard switching band unit, as it will operate in hybrids between bands and protocols (2G/3G) as it scans for networks.
To fully adapt a device to a different network environment, extensive and thorough programming is required, along with good relationships with people on the 'inside,' or people who can get a foreign device activated on the new network. Another option would simply be to pay for a Verizon plan, but operate the phone itself on the Sprint network by flashing a divested PRL, which tells the phone to primarily use Sprint's backhaul, or network, to carry a Verizon customer's traffic - or even vice versa.
Unfortunately, though, the 4G experience will not longer be. The 4G bands on the devices differ at the hardware level, so there is no possibility of transferring the device for use with foreign 4G networks.
$39 Billion is a lot of scooby snacks... and though I am aware that there are several regulatory hurdles to clear (SEC and FCC at the moment), I assume these beeeeches will lawyer up and find a way.
So from what I understand (which admittedly is very little) the existing Tmob towers will be re-purposed for rolling out Ma Bell's LTE coverage (within 12 months). As we all know, Ma Bell and Tmob use different broadcast frequencies for their Mobile broadband. So essentially, within a years time... those whom own a Vibrant, Vib + or any other 3g enabled Tmob smartphone... will have a very expensive edge capable device... ewwwwwwww, really !?!?!?!?!?!
Has there been any other word on this... as in compensation, grandfathering of packages (AT&T data plans blow money-wise) etc...
I know we have some Tmob sources on this board... any whispers???
Vibrant supports GayT&T bands, im unlocked.
Sent from my SGH-T959 using XDA App
tng222 said:
Vibrant supports GayT&T bands, im unlocked.
Sent from my SGH-T959 using XDA App
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Umts and hsupa ????
droppin the know...
Vibrant is supports some AT&T's 3G bands. Most of the time, you'll be on AT&T's 3G, but you can also get kicked down to edge if the area you're in doesn't support Vibrant's 3G bands.
Nope, it does 850mhz and 1900mhz, all bands. However, I will admit the phone has issues switching between GSM and WCDMA, so I set it to WCDMA only.
Sent from my SGH-T959 using XDA App
Read today that AT&T may have to divest part of T-Mobile to Sprint
http://www.tmonews.com/2011/03/analysts-say-att-will-have-to-divest-part-of-t-mobile-possibly-to-sprint/
T-Mobile is becoming a rag doll...
This is going to be more fun than the Sprint Nextel fiasco.
I don't think there is much mystery as to what will happen. This is AT&T we are talking about, after all.
While a nice bonus, the additional subscribers to AT&T's user base is really a secondary concern. AT&T's prime target were the (leases for) T-mobile's frequencies.
AT&T's network is already overloaded (thanks in part to weak infineon radio chipsets). They need to start the roll out to LTE to compete (verizon is already ahead of them), and they know that customers will cry foul and leave if their LTE and HSPA+ phones do not get service any faster than current 3G phones (see: Motorola Atrix).
So, what will happen to T-mobile users? Simple... AT&T will honor existing contracts and arrangements *for 2G/3G service* (T-mob does not have 4G, despite the marketing), and they will issue T-mobile users new phones (some discounted, I am sure) for use on AT&T's existing network.
What does this mean for T-mobile customers? Say good-bye to being able to answer a phone call at a concert or college football game. Being on the largest network means having to share bandwith/frequency with the largest number of users. They will fight for service with all those people with sh*tty iphone antennae.
Slower data, locked down Android phones, and higher rates for service if you want to sign a new agreement are what will inevitably happen. Current AT&T customers probably won't notice a difference unless they get an LTE phone (in which case they will get the faster data and non-overloaded service that T-mobile customers are used to).
T-mo 3G coverage will get better in smaller towns & cities, but this isn't much of an advantage for me since I live in a large city.
I hope that if that happens and I can't use my phone in their network, I'm given the option of just cancel my contract...
tng222 said:
Nope, it does 850mhz and 1900mhz, all bands. However, I will admit the phone has issues switching between GSM and WCDMA, so I set it to WCDMA only.
Sent from my SGH-T959 using XDA App
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Click to collapse
Really don't think so. FCC documents only say 1900MHz for 3G. Who knows though?
I just hope we can continue to use smartphones on prepaid plans. That's really why I left Ma Bell.
Tarzanman said:
I don't think there is much mystery as to what will happen. This is AT&T we are talking about, after all.
While a nice bonus, the additional subscribers to AT&T's user base is really a secondary concern. AT&T's prime target were the (leases for) T-mobile's frequencies.
AT&T's network is already overloaded (thanks in part to weak infineon radio chipsets). They need to start the roll out to LTE to compete (verizon is already ahead of them), and they know that customers will cry foul and leave if their LTE and HSPA+ phones do not get service any faster than current 3G phones (see: Motorola Atrix).
So, what will happen to T-mobile users? Simple... AT&T will honor existing contracts and arrangements *for 2G/3G service* (T-mob does not have 4G, despite the marketing), and they will issue T-mobile users new phones (some discounted, I am sure) for use on AT&T's existing network.
What does this mean for T-mobile customers? Say good-bye to being able to answer a phone call at a concert or college football game. Being on the largest network means having to share bandwith/frequency with the largest number of users. They will fight for service with all those people with sh*tty iphone antennae.
Slower data, locked down Android phones, and higher rates for service if you want to sign a new agreement are what will inevitably happen. Current AT&T customers probably won't notice a difference unless they get an LTE phone (in which case they will get the faster data and non-overloaded service that T-mobile customers are used to).
T-mo 3G coverage will get better in smaller towns & cities, but this isn't much of an advantage for me since I live in a large city.
Click to expand...
Click to collapse
i think t-mobile does a great job in coverage, i get full service in my neighborhood but i dont get 3g service, maybe this will help? if not i just want to cancel my contract and switch to verizon
After the merger is done and the network has switched over...Worse case, I hope to unlock, pop in a AT&T SIM continue to use my Vibrant mostly like nothing has changed. I don't know what effect flashing a Captivate modem would have. I'm not worried...yet.
I think AT&T might make a transitional phase (2-4yrs) for T-mobile existing customers(no new AWS phones) before switching all T-mobile network to AT&T frequencies.
http://www.cnet.com/8301-17918_1-20048020-85.html?tag=TOCmoreStories.0
I hope sprint gets it! I never had and never will have at&t.... I price checked with at&t a few days ago.. 210 dollars for 2 unlimited lines!?!? Data capped at 2Gigs.. And 10 bucks for every gig used after!? I pay 140 for two fully loaded vibrants. . Fack at&t
Sent from my SGH-T959 using XDA Premium App
nate420 said:
210 dollars for 2 unlimited lines!?!? Data capped at 2Gigs.. And 10 bucks for every gig used after!?
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Unlimited...
gamikzone said:
i think t-mobile does a great job in coverage, i get full service in my neighborhood but i dont get 3g service, maybe this will help? if not i just want to cancel my contract and switch to verizon
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Click to collapse
Same Here. I have been with T-mobile for 7 years now and even though I moved from a "4G" area to an area where I only get Edge, i still have stayed with T-Mob, but I am hoping we get the option to cancel our contracts because that Thunderbolt from Verizon is looking good. My co-worker has one and let me mess with it and it is nice.
Tarzanman said:
I don't think there is much mystery as to what will happen. This is AT&T we are talking about, after all.
While a nice bonus, the additional subscribers to AT&T's user base is really a secondary concern. AT&T's prime target were the (leases for) T-mobile's frequencies.
AT&T's network is already overloaded (thanks in part to weak infineon radio chipsets). They need to start the roll out to LTE to compete (verizon is already ahead of them), and they know that customers will cry foul and leave if their LTE and HSPA+ phones do not get service any faster than current 3G phones (see: Motorola Atrix).
So, what will happen to T-mobile users? Simple... AT&T will honor existing contracts and arrangements *for 2G/3G service* (T-mob does not have 4G, despite the marketing), and they will issue T-mobile users new phones (some discounted, I am sure) for use on AT&T's existing network.
What does this mean for T-mobile customers? Say good-bye to being able to answer a phone call at a concert or college football game. Being on the largest network means having to share bandwith/frequency with the largest number of users. They will fight for service with all those people with sh*tty iphone antennae.
Slower data, locked down Android phones, and higher rates for service if you want to sign a new agreement are what will inevitably happen. Current AT&T customers probably won't notice a difference unless they get an LTE phone (in which case they will get the faster data and non-overloaded service that T-mobile customers are used to).
T-mo 3G coverage will get better in smaller towns & cities, but this isn't much of an advantage for me since I live in a large city.
Click to expand...
Click to collapse
T-Mobile has a better "4G" than AT&T does. Their HSPA+ is faster than AT&T's.
dligon said:
http://www.cnet.com/8301-17918_1-20048020-85.html?tag=TOCmoreStories.0
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Completely agree with the article.
They are allowing AT&T to be a monopoly again,after all the work it took to destroy the monopoly.The FCC should shot down this deal period.
Thoughts?
Sent from my SPH-D700 using XDA App
Not until every single nextel contract is over at the very earliest.
There's never will. I work for sprint and the next thing for nextel is the door in 2013
Sent from my SPH-D700 using XDA Premium App
063_XOBX said:
Not until every single nextel contract is over at the very earliest.
Click to expand...
Click to collapse
Not necessarily. When ATT upgraded from edge to umts did they kick out all the edge users on umts frequencies, no. All they had to do was allocate enough of the spectrum to accommodate the edge users and move the rest to umts.
Sent from my SPH-D700 using Tapatalk
I'm not sure if Nextel will ever get 4g. I do know for a fact Sprint is phasing out Nextel's network over the next 2-3 years and transferring their accounts to Sprint frequencies.
Sent from my SPH-D700 using XDA App
IDEN is scheduled fror decommission over the next 3 years, why invest in the technology if its already scheduled to die.
Plus, I don't think IDEN technology was optimized enough to support advanced data speeds, that was never its reason of existance.....
Sent from a cave.....
I think there is some confusion to the OPs topic. Sprint will be pushing the kill switch on Nextel/IDEN technologies of the next few years. IDEN is not intended for LTE or data at all. The OP is alluding to the fact that when IDEN is actually dead, there is a lot of free spectrum in Sprint's hands (Spectrum != Protocol) Spectrum that can be used for LTE Transmission. This has been speculated for a long time and 'Project Leap something or another' is supposed to put the theory into action.
The 800MHz frequencies will probably see CDMA on them within the next year. There is more than enough unused resources to allocate 5MHz of the 15MHz sprint has in the 800MHz area to use CDMA. Most areas as it is only use 5MHz worth of sprints 1900MHz spectrum. Since just about every sprint phone as it is roam verizons 800MHz, it's nothing more than sending out a new PRL to take advantage of this. I expect that once IDEN is gone, sprint will use 10MHz in the 800MHz to utilize LTE as well as their 2.5GHz. I'm willing to bet that Sprint will eventually switch to LTE entirely across all of their frequencies. LTE has very low latency and Sprint will continue to cater to business who rely on the sub-second speed of their current IDEN radio use.
LTE can utilize multiple frequencies simultaneously, which means that we, the end user, will benefit greatly. It will be no problem for someone to use a 10MHz block of 800MHz and 10MHz block of 1900MHz simultaneously. There are some very cool things coming in the next few years, and I'm glad sprint is getting on board early.
The benefit of lower frequencies is their ability for penetration, while the benefit of 2.5GHz is the fact that sprint has access to around 170MHz of total bandwidth. The network will be a combination of super high speeds for stationary home solutions while having excellent mobile coverage everywhere. Very cool things are coming.....I can't wait.
Lol....never....
Good Old Nextel was the Shiznit in its day now a 2G Dino , never will it see anything but scrapyard and like earlier posts suggest reuse its BW
Quis89 said:
Lol....never....
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Click to collapse
Never what? Sprint already said that 800 will be CDMA, and the new PTT CDMA devices drop in a few months. Hell, all their current IDEN users could use but 5MHz and still be covered.
It's inevitable that LTE will be the only choice in the future. CDMA, like IDEN, will eventually be a thing of the past. Cellular networks are gaining customers, but we're not gaining frequencies. As more people use the same frequencies, the switch to more efficient means of handling them must happen. Everything will eventually be IPv6 data only. The current GSM and CDMA will be replaced by newer protocols. Call quality will continue to increase as well. Hell, a lot of my calls are already QIK video chats.
NoSoMo said:
Never what? Sprint already said that 800 will be CDMA, and the new PTT CDMA devices drop in a few months. Hell, all their current IDEN users could use but 5MHz and still be covered.
It's inevitable that LTE will be the only choice in the future. CDMA, like IDEN, will eventually be a thing of the past. Cellular networks are gaining customers, but we're not gaining frequencies. As more people use the same frequencies, the switch to more efficient means of handling them must happen. Everything will eventually be IPv6 data only. The current GSM and CDMA will be replaced by newer protocols. Call quality will continue to increase as well. Hell, a lot of my calls are already QIK video chats.
Click to expand...
Click to collapse
sucks, i dont want people to be seeing me when i make those calls lol. weird
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.