Is it possible to convert a cdma phone into a gsm phone by use of software only?

If a cell phone has the same network technology (CDMA) as your current service provider (Cricket), how is it programmed to be used with the company? I just recently purchased a cell phone "flashed" for Cricket services.

I am moving to South Korea and my carrier cingular told me that if i got a korean sim card i could just switch out the cards . Is this possiable or true? Any suggestions? I wanted to do this,because i am still under contract and my roaming charges would be 2.29 a min or pay 175 to cancel. If so where can i buy this card?

Re anon130: Sorry, it's kind of like the difference between VHS and Beta video tapes... while to the user they do pretty much the same thing, their insides are quite different. It would be like converting a car to run on railroad tracks. That said, there are some trucks that do run on rail tracks, and there are also some CDMA phones that will work on GSM, so you can add a GSM SIM card and talk away. An example of this is the Samsung SCH-i830. You will pay much more for it than a regular phone, but will work on either system.

Re: kree8: For a CDMA phone to work on the network, there are three things that need to be set up. First, the network operator (in your case, Cricket) needs to add the phone's serial number to your account, so they will know who to charge for the calls. Second, you (or your friendly neighborhood Cricket service person) needs to change the MIN (Mobile Identity Number, effectively your phone number) in the phone's NAM (Number Assignment Module). How it's done depends on the phone, but usually it involves picking a hidden choice from a menu or entering a strange number, after which the phone will show a screen with the current numbers, and give you the option to change them. The final part is the PRL (Preferred Roaming List), which is effectively a list of the cell phone towers that your phone should use first, so that you don't get roaming charges when your company has a tower in range.

You might wonder why your phone number has to go in your phone, when your cell company already knows that it's your phone. Well, most phones let you have more than one number, set up with different cell companies, and let you choose which one is to be used. Only one number can be in use at a time. It is useful, for example, if your office gives you a cell phone, and you want to use your own number for personal calls, nights, or weekends, and only want to carry one phone. Of course, the cell companies wouldn't want you using *their* phone on someone else's network, so some of them use a 6-digit code, called a MSL (Master Subsidy Lock), to keep people from adding or changing the phone number on the phone. Some companies (like Sprint and Telus)won't let your phone on their network unless they have a record of them selling that phone's serial number.

Things should get easier in the future, since back in 2002 there was something introduced called a R-UIM (a Removable User Identity Module), a little card that looks a lot like the SIM cards the GSM people have. It has a serial number that represents your account, and all the other information needed for your phone to work. You can put your R-UIM card in any compatible phone, and suddenly, it works just like the phone you took the card from. Additionally, the R-UIM card will work in GSM phones to let you roam in GSM areas, as long as your cell company has a roaming agreement in place with the local service provider.

Re: anon423. Sure, it's true. Before you go to Korea, though, you probably need to get a SIM Lock code from your current carrier to unlock your phone, so when you do get a Korean SIM card, your phone will let you use it. You should be able to pick up prepaid SIM cards or sign a contract with a Korean GSM carrier to get a new SIM card. Of course, you will still have to pay your Cingular bill each month, so it may be cheaper for you to pay the $175 to get out of your contract, but don't forget to wait until after you get the code to unlock your phone.

How would you program, using c or java, the roaming light on your cell phone to flash?

I'm in the process of buying a new phone, and in the meantime switching from Cricket to either Sprint or T-Mobile. Sprint has the phone I like (Samsung M500), as well as the plan I need, while T-Mobile has the international roaming I need for my upcoming trip to Egypt ($1.99 per minute!!). Lost and confused; please advise, should I buy the phone above -unlocked- off e-bay and get it programmed with Sprint, or would a SIM card work when it is time to use it?

will gsm phone work on cdma network?

CDMA providers generally offer better chances for roaming in rural areas, as most of their handsets are compatible with existing older analog infrastructure.

Also, the assertion that GSM carriers are the only ones who have roaming agreements in place is incorrect. Sprint, Verizon, and Alltel all have various voice and data agreements in place.

I think perhaps this article is out of date...?

I have a old ATT plan (never switched to Cingular), now they are back to ATT but I can not get a replacement phone that will work with my old ATT sim card without getting a new plan. Can you help me get a compatable phone or copy my sim informtion on a newer GSM sim card??

About the korean ordeal. Im a GI stationed here and I was going to do the same thing with my unlocked tmobile phone. Sadly the korean market doesnt support sim cards. I have searched all over Seoul and found nothing. So when you get here you will have to buy a korean junky phone and a junk minutes plan. Contracts are 6 month contracts here its like 35 bucks for 200 incountry minutes and texting. The prepaid phone is more common than in america here. If your gonna be calling back to the states I recommend a Purple Miracle card. Its setup for mobile prepay services. Safe travels

To "Anonymous", who asked:

"Is it possible to convert a cdma phone into a gsm phone by use of software only?"

No, they have very different hardware internally.

I have heard a rumor that in America, CDMA will no longer be supported after 2008. Have you heard anything? Thanks.

i want to do my final year project on nss gsm/cdma ,plz give me guideline from where i should really start my project ,how can i make it more attractive so that it meets the requirements of the day

Re: CDMA in 2008

Some companies (notably OnStar) are dropping subscribers that have AMPS-only (analog) equipment on January 1st, 2008. The current story is that some of the cell networks are going to shut down the older analog system, in the belief that the newer digital systems have enough coverage.

Many (not all) CDMA phones also have AMPS capability, a very useful thing where CDMA coverage is weak and AMPS towers are still active. In fact, some phones (like the Audiovox Thera, which is CDMA-only) were considered bad for voice use because they couldn't fall back to AMPS when there were gaps in CDMA coverage. Thankfully, CDMA coverage is a lot better now.

Some people could be confused, thinking that if the AMPS network goes down, their CDMA phone won't work. This is not the case. The AMPS network was an added bonus, but your CDMA phone will still work on the CDMA network. You may even be able to get longer battery life by setting your phone to digital-only operation.

By the way, AMPS stood for Advanced Mobile Phone System, and functioned similarly to the TACS system in Europe. There were other evolutionary upgrades to AMPS. First, they added extra channels when more spectrum became available. Then there was NAMPS, Narrow AMPS, which divided each AMPS channel in thirds, and brought the potential number of channels to over 2400. NAMPS could handle three times as many calls as AMPS, just like TDMA and GSM. Then came DAMPS, Digital AMPS, but by that time, TDMA and GSM had already taken hold. And for comparison, a CDMA network can handle more than 3 times the calls of a NAMPS, GSM, or TDMA network, which in turn, could handle 3 times as many calls as the AMPS network.

It makes me wonder why there are places that still use TDMA, and how GSM ever managed to take hold in the first place, with their reduced call density.

I just finished signing up with AT&t a.k.a Cingular. which promised coverage in south korea with only 2 phone modules that are quad band and smart phone that will work there. one of them being a Treo series phone and other that is actually a AT&T phone. i can't remember exact models but call a representative and they are more than willing to explain this to you. I will be stationed there for the next year so i wanted to keep a state side number for my kids sake just in case anything did happen. :-D

Important Information When You Travel to Japan or South Korea

You'll need a device that operates on 3G technology at 2100 MHz to roam in Japan or South Korea.

AT&T now sells several 3G 2100HMz devices, like the Treo 750, the AT&T 8525 and the Sierra PC card for travel worldwide, including Japan and South Korea, or you can rent a 3G 2100 MHZ phone from Cellhire at www.cellhire.com/att and just insert your SmartChip™ into the phone.

With AT&T World Traveler, calling while in Japan is only $1.69/minute!

You will receive an invoice from Cellhire for the handset rental but your calls will appear on your monthly wireless bill from AT&T.

It is said that CDMA data transfer is more reliable and safer than GSM, how is it possible?

Which is LESS likely to get bugged, CDMA or GSM?

GSM phones will not work over CDMA network and vice versa. GSM phones require SIM cards which is activated by the network provider.

It is important to know what frequency your phone is available to. If you bring your phone to a different country it could work if.. 1) phone wasn't locked by your current network provider - it is hackable anyway 2) frequency of network matches

CDMA will not go away in the US for a couple of reasons. One it will cost a great deal of money changing infrastructure network. Two they will lose customers because they also have to change phones that can support a sim card.

in Egypt we use GSM netwark and i have a CDMA phone. i can't use it. what i have to do for using the phone with our network?

Cannot tell you as a really non-technical person how HELPFUL this article was in my decision as to what type of phone I am bidding on in an auction! THANKS!

Can I change software for phone work with CDMA to work with GSM?

Will a gsm phone work on any other gsm network? I want a phone from a different provider and don't want to change as I am under contract.

I currently have Sprint PCS as my cell phone carrier, and Sprint uses the CDMA network. However, I would like to buy an unlocked phone on the internet which would be much cheaper and there's more variety available than buying directly from Sprint. I would like to know if I can buy an unlocked phone and use it with my Sprint coverage. I do not want to change plans or my carrier.

Is it possible to buy a GSM unlocked phone and use it on the CDMA network such as Sprint? if it is possible, how do I do it? is there a particular make/model phone that I should get?

Thank you.

I travel frequently to rural Iowa and currently use the Treo 750. This phone is a UMTS based phone that works great in major cities but the service stinks in rural Iowa. In fact, it cannot even function as a basic phone most of the time. Any suggestions on a windows based phone that will give me the bells and whistles in the major cities and at least maintain a phone call in rural America?

I have a T-Mobile Triband phone made by Nokia. I've used it all over the world and it works great. It's a GSM phone. To add international calling to my plan costed me $0 - nothing! All I pay extra for are the minutes.

From what I know, the GSM network is superior to CDMA because it's all digital. Also, when switching phones all you do is swap the SIM card with GSM phone. All my phone information and contact numbers carry over to my new phone. I just laugh at my friends who have CDMA phones. Thay have to reprogram and reenter ALL of their personal information!!

To the last comment about GSM being superior to CDMA because it's all digital.

1st: CDMA is a much more superior technology, Yes it is all digital and extremely more secure than GSM in terms of eavesdropping and hack/clone capability. Yes, this still happens in 2007.

2nd: Just because Europe has mandated GSM as their technology, doesn't mean all of the world GSM is used. If you live in North/South America CDMA is the most dominated technology with more coverage than GSM Carriers. Even if you are in Brazil, US, Canada...etc. Most Asian countries have adopted CDMA! South Korea, All CDMA, All new Carriers in Japan CDMA,....Australia, New Zealand....cdma. It's growing, and growing quick because CDMA can handle 3-5x the amount of customers per tower and at Data rate GSM cannot achieve.

3rd: GSM you might be able to move a chip from phone to phone...but first you have to ask yourself if you're living somewhere like the states...why are you switching back and forth on phones that much. Also with carriers like Verizon, you can switch via phone/internet in less than a minute and your new phone will be working with the ability to have all your contacts moved over WIRELESSLY...and saved to your account online! Your GSM phone doesn't automatically upload contacts daily wirelessly. Sucks for GSM people if they lose there phone.

4th: GSM IS EVOLVING TO CDMA! What is wrong with you people? Most countries have already mandated that WCDMA is the global standard, because the standard GSM network can't handle what they have already.

5th: There are very very few phones that work on all the networks, and there is no SUCH THING as every single network.

You have: GSM 450(mostly india)/700(soon)/800/900/1800/1700(soon)/1900 and now (WCDMA for GSM) 2100mhz

You have CDMA: 450(poland/norway/portugal/sweden/demmark/iceland)/700(soon)/800/1900mhz.

Most GSM tri/quad band phones only support up to 4!

Quad Band CDMA Phones: ONLY UP TO 4!

6th: Network Speeds is where CDMA spanks for downloading/uploading and surfing the web:

3G-CDMA EVDO Sprint/Verizon 2.4mb/s Max download, avg 400-700kbps

Upload: 384kbps max, average 160-240kbps

3G-CDMA EVDO-Rev A Sprint/Verizon 3.1mb/s Max download, avg 500-850kbps

Upload: 1.8mbps Max, average 220-580kbps

4G-CDMA EVDO - Verizon LTE (WiMax possibly sprint) Think of your WIFI at home with super fast connection on steroids: 100mbps Download, 50mbps upload!

BOTH Carriers and many others around the world launching in 2008!

2.5G-GSM EDGE Tmobile/ATT(cingular) Download: 1mb (8packet GSM, most areas are 4packet, which is half the speed), average is 80kbps -120kbps,

3G-GSM UMTS ATT/Cingular (not available with Tmobile) 2.1mbps (no matter on packet always up too 2.1) average 300-500kbps.

Upload: 120-240kbps.

4G-GSM Next evolution of UMTS-HSDPA, not beginning til late 2009! UMTS caps at 14.4mbps, and 3.6mbps upload.

Think about all this when you see a network like KDDI Japan, to launch really high quality Video with sound calling LIVE over their network. It's not a possibility on GSM, Wonder why they are stealing tons of subscribers from DoCoMo Japan.

Read facts, work in the industry and do some research before you post on websites like this!

Verizon announced that in 2008 it will open up its network and will let customers use a broader range of cell phones and wireless features on its network. Does it mean that customers will be able to use any unlocked mobile phones (including SIM card phones) with Verizon? If this is correct, how will it work?

To the person who posted "To the last comment about GSM being superior to CDMA because it's all digital", you really need to check your information.

Firstly, many CDMA networks around the world are in the process of being replaced with 3GSM (WCDMA, UTMS or whatever you want to call it) networks including the Telstra CDMA network in Australia and the Telecom New Zealand CDMA networks that you mention.

Also, you mention LTE under Verizon. Verizon has announced that they will eventually move over to LTE which is actually a 3GSM based standard and yet you have lumped it in under Qualcomm CDMA.

In addition, DoCoMo in Japan uses a system called FOMA which was used as the basis for the development of the 3GSM (UMTS) system not the old 2G GSM standard.

Furthermore, at the moment 3GSM HSUPA networks kick butt over CDMA EV-DO Rev A networks for data uploads and downloads. However, as this is a new upgrade to the 3GSM standards it has not been widely rolled out.

One of the big advantages that CDMA had over GSM is that the upgrades from CDMAone to CDMA2000 1xRTT and EVDO were all relatively simple, and mainly software based, while there was a complete change to the air interface between GSM and 3GSM. Hence networks had to basically build new networks to upgrade to 3GSM, slowing down the rollout of 3GSM services compared to CDMA2000 EVDO.

In Canada the largest carriers are CDMA I use Telus (CDMA) but have the option of getting a Motorola 840 world phone which uses CDMA in NA and can take a sim card for overseas roaming.

There are rumours that Telus will start the switch to GSM when they start their new network build out.

Also there is an upcoming spectrum auction with 40% reserved for new players, which will hopefully create some real competition here.

TTFN from Canada

I just switched from U.S. Cellular to prepaid Airvoice Express. How or where do I get my Motorola V262 CDMA phone flashed to Verizon or Alltel which is the network Airvoice Express uses? I have the subsidy code but that only allows me to change MIN, etc. The phone is still looking for U.S. Cellular.

very informative for learners.

Hi, I am living in South Korea now. I do like to travel to the other countries here, and back home to North America.

Can I get a CDMA phone here (I understand from this and other articles that only CDMA is here), and use SIM cards in other countries here in Asia, like Thailand, China, Philippines, New Zealand, etc...?

What might be the best option for me to go>

Thanks

In cellular service there are two main competing network technologies: Global System for Mobile Communications (GSM) and Code Division Multiple Access (CDMA). Cellular carriers including at&t wireless, Verizon, Sprint-Nextel, T-Mobile and smaller carriers use one or the other. Understanding the difference between GSM and CDMA will allow you to choose a carrier that uses the preferable network technology for your needs.

The GSM Association is an international organization of cellular carriers founded in 1987, provide coverage worldwide using the European ETSI wireless standard GSM. CDMA, a competing US standard originally designed by Qualcomm in the United States is used mainly in America and parts of Asia by other carriers. T-Mobile and at&t follow the GSM standard and Verizon and Sprint use the CDMA standard. Nextel uses a third standard developed by Motorola called iDEN. There are camps that firmly believe their architecture and protocols are superior to the other. That said, to the non-invested consumer who simply wants bottom line information to make a choice, the following considerations may be helpful.

anon5910,

You have quite a lot of your facts confused. Let me clarify a few of them for the readers.

>1st: CDMA is a much more superior technology, Yes it is all digital and extremely more secure than GSM in terms of eavesdropping and hack/clone capability. Yes, this still happens in 2007.

CDMA and GSM are both digital. AMPS, the analog standard, has been completely phased out. Nothing is 100% secure. Both CDMA and GSM are subject to being hacked.

>2nd: Just because Europe has mandated GSM as their technology, doesn't mean all of the world GSM is used. If you live in North/South America CDMA is the most dominated technology with more coverage than GSM Carriers. Even if you are in Brazil, US, Canada...etc. Most Asian countries have adopted CDMA! South Korea, All CDMA, All new Carriers in Japan CDMA,....Australia, New Zealand....cdma. It's growing, and growing quick because CDMA can handle 3-5x the amount of customers per tower and at Data rate GSM cannot achieve.

More nonsense. Some carriers decided to go with GSM others with CDMA. 218 countries have GSM service. 22 countries support CDMAone. at&t, the largest carrier in the US and T-Mobile (they're German) use GSM. T-Mobile grows by more than 1.3 million subs a quarter now. On the CDMA side, Verizon, used to be the largest carrier, is now second behind at&t. They constantly have to remind us "it's the network" and show you how many people it takes to maintain the network. Sprint is losing customers at around 1.5 million per quarter. It seems like they have a ghost town on their hands. They too use CDMA. I see a little pattern forming here.

>3rd: GSM you might be able to move a chip from phone to phone...but first you have to ask yourself if you're living somewhere like the states...why are you switching back and forth on phones that much. Also with carriers like Verizon, you can switch via phone/internet in less than a minute and your new phone will be working with the ability to have all your contacts moved over WIRELESSLY...and saved to your account online! Your GSM phone doesn't automatically upload contacts daily wirelessly. Sucks for GSM people if they lose there phone.

Consumers like new phones about every 2 years or so just like they update their computers, laptops, operating systems, game consoles, cars, TVs,... I take it you are still using the same brick you had in 1995 when they invented CDMA?

>4th: GSM is evolving to CDMA! What is wrong with you people? Most countries have already mandated that WCDMA is the global standard, because the standard GSM network can't handle what they have already.

Not exactly. You are confusing upper layer protocols with underlying RF modulation and channel access schemes. Both 3G CDMA (1xRTT, EVDO) and 3G GSM (UMTS, HSPA) use the same RF modulation and access scheme WCDMA. Both network handle their upper layers in a different way, but there really are no huge earth shaking differences.

>5th: There are very very few phones that work on all the networks, and there is no such thing as every single network.

>You have: GSM 450(mostly india)/700(soon)/800/900/1800/1700(soon)/1900 and now (WCDMA for GSM) 2100mhz

>You have CDMA: 450(poland/norway/portugal/sweden/demmark/iceland)/700(soon)/800/1900mhz.

>Most GSM tri/quad band phones only support up to 4!

>Quad Band CDMA Phones: only up to 4!

I think you are confusing a whole lot of issues here. 1) RF spectrum 2) RF Modulation and channel access and 3) upper layer protocols.

You are entirely right. There is no swiss army knife of mobile phones.

>6th: Network Speeds is where CDMA spanks for downloading/uploading and surfing the web:

>3G-CDMA EVDO Sprint/Verizon 2.4mb/s Max download, avg 400-700kbps

>Upload: 384kbps max, average 160-240kbps

>3G-CDMA EVDO-Rev A Sprint/Verizon 3.1mb/s Max download, avg 500-850kbps

>Upload: 1.8mbps Max, average 220-580kbps

GSM's 3G HSPA has speeds up to 14 mb/s. at&t and T-Mobile are there, if not, working on it.

>4G-CDMA EVDO - Verizon LTE (WiMax possibly sprint) Think of your WIFI at home with super fast connection on steroids: 100mbps Download, 50mbps upload!

Yes, and GSM carriers will be using the same technology - LTE... and your point is?

>both Carriers and many others around the world launching in 2008!

My prediction: Sprint-Nextel will be bankrupt. They can't afford any Wi-Max plans. Clearwire has already had layoffs too. I don't see it happening.

And Verizon will still need to run around and send people around town testing their network "Can you hear me?" or sending a whole town's worth of repair crews behind users to fix the phones.

>2.5G-GSM EDGE Tmobile/ATT(cingular) Download: 1mb (8packet GSM, most areas are 4packet, which is half the speed), average is 80kbps -120kbps,

>3G-GSM UMTS ATT/Cingular (not available with Tmobile) 2.1mbps (no matter on packet always up too 2.1) average 300-500kbps.

>Upload: 120-240kbps.

>4G-GSM Next evolution of UMTS-HSDPA, not beginning til late 2009! UMTS caps at 14.4mbps, and 3.6mbps upload.

yea ... yea ... These are just numbers being thrown around. Did you ever get 54Mbps on your Wi-Fi?

>Think about all this when you see a network like KDDI Japan, to launch really high quality Video with sound calling LIVE over their network. It's not a possibility on GSM, Wonder why they are stealing tons of subscribers from DoCoMo Japan.

No one watches TV or movies on their phone. Verizon tried it and got out of the business.

>Read facts, work in the industry and do some research before you post on websites like this! I seriously think you should.

I have 2 treo's one gsm, one cdma. I want to know if I can rebuild the CDMA by putting the GMS SIM holder daughter board on the CDMA motherboard and load cingular firmware.

I have gutted both phones, and they identical except CDMA has no daughter board, but the pins are there and I have put the daughter board on and have re-assembled the phone, it works the same as it did. I have no service on the cdma so it wont connect, I have cingular service, but my cingular treo is dead, so when I got the second treo, I thought it was a unlocked gsm, and I was sent a CDMA, So ......... can I now load cingular firmware and hope that the phone will except it, or will I screw up the perfectly functioning CDMA treo that I just use for fun, not as my cell at the moment.