If CDMA is so good than y r carriers not going for it in some asian countries like India?

I use a small cell phone company. How can I find out if they are gsm?

An urgent answer is needed please. I mistakenly flashed my GSM phone with a CDMA update utility and the phone has ceased any function. Does anyone have any idea on how to bring the phone back to its normal state? help me please.

Hey, anon2716

If your phone is too old, perhaps this isn't possible, but couldn't you simply save your data to your pc, then download it onto the new sim card?

I live in a rural area and we had two choices then, verizon (cdma) or cellular one (gsm), i picked verizon bc cellular one was not well known to me anyways had nothing but problems with verizon.

we cant get service in our local walmart. i couldn't even get a signal at my grandmother's house. she lives in nahant, massachussets. a little island contected to the main land by a cos way. if i wanted to make a call i had to walk across to the beach and i was lucky if i got a call through.

about 5 years later, i paid the bill over the phone and the canceled my account and kept demanding us to pay the bill for six months afterward.

then we switched to cellular one and it was great better coverage than verizon and the walmart i mentioned earlier shut down and they built a walmart super center. with verizon, as soon as u get in the door u lose the signal. cellular one got five bars all over the store and i have people staring at me when i make a call bc most people in my town have verizon. then at&t bought out cellular one and i still have the great service, but a more well known name. lol.

more and more people are getting rid of verizon and switching to at&t here.

with verizon the network didn't do it for me. we had a lot of dropped calls the signal was terrible. the signal didn't penetrate a lot of brick, steel, etc buildings like Cellular One and at&t do.

its kind of ironic how a lot of people complain the gsm doesn't have good coverage in rural areas, but in my area it has better coverage that cdma lol

What's the point of 3G? I'm about to buy a quad-band GSM phone which I want to use worldwide only for calling (no internet etc.). Will the 2G technology at some point "disappear," so that a phone without 3G gets useless? Or will I have a better reception with 3G--those are different towers, correct? Or is 3G just for having a *faster* connection (I don't care b/c I only want to call)? And are there countries in which you *need* G3? Thanks a lot! David

Hi i am swaid, i live in kashmir india...its good to use gsm phones than cdma because of unlimited features....

Well, being someone that has worked for Alltel for more that 6 years and having friends that work for At&t, I have to say that CDMA is the way to go. Most GSM carriers are moving to UTMS, which is wide band cdma. Call clarity is better and advances in what you can do with a CDMA system is so much better than those of a GSM system that still holds roots to a TDMA type system. Eventually though all carriers are gonna try to move to an LTE system or a WiMax system. 4G is coming before you know it.

I am neo, and i say that GSM is the one!

I have US Cellular, but they don't offer any Military Spaec phones like the samsung rugby. My work has me in the elements all the time so I'm constantly having to use my signal ins to get new phone. The providers ATT & Nextel Sprint there coverage in my area is very poor unless just on major road ways. Rural areas are non operating. Can I get one of these military phones and make work in my US Cellular plan. Any reason they (US Celluar) don't offer these tough phones? Please advise I'm on phone # 3 this year

what does the kyocera cyclops have GSM or CDMA? does anyone know whether these USB cables work for this phone or not ( KX5B K322 K323 K325) or (K320 K312 K132 K310)?

I have not heard anyone mention the range difference on CDMA/GSM networks? There are many arguments about data speed, software, and countries, but not much about the tech specifically.

The reason that one person above was getting better service with a CDMA phone in the sticks could be (I read somewhere) that CDMA towers can get a signal to 10-12 miles, while GSM was only 2-4 miles. Some field test in Kansas proved the theory.

Would this be because of a switch to AMPS at that distance, and the power of the CDMA phone itself is putting out more wattage?

I have noticed that the GSM phone technology is getting insane with watch phones that can hold 4 GB of video, too. CDMA's don't have anything like this. So, is it because it takes a more powerful tech on a CDMA?

Can anyone verify the range difference, and why?

Hi, i live in Yemen and there are 3 GSM companies and one CDMA company but what i want to say is that CDMA is more cheaper and covers more rural area than the 3 companies that use GSM tec. But the CDMA phone are not cool at all

i have an unlocked blackberry but no service can i put a tracfone sim card in it and will that work?

Thank you for providing useful information on CDMA and GSM technologies. We expect to learn more from you. RaviKanth Kontham

Are all smartphones (PDAs, Crackberries, etc.) GSM, or are there CDMA smartphones?

The reason I prefer GSM simply a matter of convenience and control. A PDA phone is apt to drop or get damaged. It is a whole lot easier to simply hit craigslist and find a used GSM phone and insert SIM card for a whole lot cheaper than some telco carrier offers their units, and I don't have to start another 3-year contract to replace a phone.

Furthermore, if I am travelling, I can get a local paygo SIM card relatively easily, and continue to use my PDA with all its information, contacts etc (which are not stored on the SIM card but on the phone itself).

QUOTE:

>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.

*************************************************

This is rubbish. As someone who lives in New Zealand and travel routinely through Australia and Asia I can tell you that most networks are GSM. The network in NZ that is CDMA is Telecom New Zealand and they are rapidly losing market share to Vodafone (GSM), so much so that they are looking at going GSM in the near future. Most business people who travel the world uses GSM because they can get a local number easily without renting phones etc.

Great informative article. I work in the cell phone industry and this has really helped my on the job education. I do have to correct you in one area. GSM has terrible rural reception. Look at the coverage maps of T-Mobile and AT&T, they are awful. They don't even work in some cities. I live in Nebraska and GSM is not even an option. If someone moves to Lincoln, T-Mobile automatically drops them because they can't make phone calls. CDMA is far superior to GSM in rural areas.

jake181318: look on ebay, and the carrier logo at start up and stuff will stay in the phone even when unlocked. you have to remove them by yourself with p2k tools (not really user friendly) but there is plenty of "how to use" p2ktools if you google it.

okay so I have the samsung stripe on a t-mobile service plan but I'm tired of not having a lot of things to do on this phone. I personally like LG phones. specifically the LG VU. I wanted to buy it unlocked and put my sim card in it. Can I do that with an LG phone? And the is the LG VU GSM or CDMA? And the LG VU is an AT&T phone so it had AT&t logos all through out the phone. If I put my sim card in the unlocked phone will those logos leave? And last does anyone know a website that sells unlocked phones for cheap?

I am visually impaired and am searching for a phone company that will provide me with the best options for my vision. Unfortunately, AT& T offers 3 phones..Pantech Duo, Nokia 75 and Motorola Q which will take the Mobile Speaks software so that the phone will perform commands without my having to see what I'm doing. These are not great options for many who have some but not a lot of sight left. I am at the end of my contract with AT& T and wonder if I should stay with them but the determining factor, I believe, comes down to the Symbian OS and what phones I can use with what companies. Am I looking for a needle in the haystack or can I use Mobile Speaks or Nuance/s Talks within any company...At& T or Verizon. Verizon's answer is the LG VX8350 and although it has its good points, is not built on a Symbian OS and you cannot use Mobile Speaks or Nuance with it. Any suggestions for a vi user? Thanks

I am a computer science student. Really this this article is very helpful. and it's giving a proper comparison in GSM and CDMA.

I was told Verizon was going to be changing over to gsm by the end of the year. Does anyone know if it's true? Thanks!

Have a little question here. I want to buy a CDMA phone from lets say Ebay and want to activate it on Virgin Mobile. Is there anything to do? Since they do not offer Blackberry, HTC or Treo and I need a full keyboard for chatting I want to buy one of these on Ebay and use it on Virgin Mobile network.

i recently bought a new GSM phone from Korea, it's a KTech T200+ it is unlocked yet my sim card fails to register. O2 informed me BEFORE i bought the phone that i wouldnt have any problem with it because their network doesn't solely rely on the 3G network

Does CDMA work in Europe or not??

What's next after GSM and CDMA?

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.

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.

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.

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

very informative for learners.

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.

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

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.

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 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!

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!!

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 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.

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.

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

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!

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?

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.

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

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

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.

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

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 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

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

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.

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

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??

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...?

will gsm phone work on cdma network?

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?

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

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.

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?

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.

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