CDMA Networks vs GSM/GPRS Networks

Forums › Mobile handsets › CDMA Networks vs GSM/GPRS Networks

JaBZ

404 posts

Ultimate Geek

#1566 19-May-2004 09:58

Kickass sorry to hear you have moved to an inferior network...

My opinions and ideas expressed in posts are solely my own and do not reflect the views of my employer in any way..

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404 posts

Ultimate Geek

#5819 18-May-2004 14:01

johnr I could do that but I won't, it'd throw this thread offtopic...
besides regardless of # users, if you know your networks then I wouldn't need to...

My opinions and ideas expressed in posts are solely my own and do not reflect the views of my employer in any way..

rck

139 posts

Master Geek

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#5823 18-May-2004 16:50

It depends what you want to use the network for, But this is Off Topic. If you want to debate the various merits and differences between the two networks then start a new thread. I'm sure there will be some heated debate sparked. Should be rather interesting I would think

skyplonk

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#5840 19-May-2004 09:38

Hi Johnr,

GSM has been around for 20years, hence why it has the biggest subscriber base. CDMA has only been around for less than 8 years. Really the amount of customers have nothing to do with how advanced technology is or which is better.
CDMA is far more advanced than GSM, It is more efficient with spectrum allocation, it voice codec on CDMA is far better than the GSM standard. The data speeds on even a IS95A or B network exceed GSM's CSD Data speeds. The CDMA transmission has a useable distance of upto 160kms, unlike GSM at about 40kms. Even though both never achieve that. CDMA does not need high latency "bolt ons" to do data at speeds anything better than a joke.

Anyway john, all 3G standards are based around CDMA. CDMA 1X RTT, EV-DO, EV-DV, TD-SCDMA, WCDMA (3GSM)
WCDMA or 3GSM as it is now called is a CDMA/CDG/Qualcomm developed technology not a GSM one. Bad mouthing CDMA is really running down any network with 3G Network plans.

Then we can start talking churn rates, and look at carriers like AT&T, canceled the upgrade of their TDMA network to CDMA at the 11th hour, to overlay with GSM and now they have the biggest churn rates out of ANY cellular network in the states, with Verzion (CDMA) picking up most of the customers. Complaints from them? Coverage, Data Speeds and Voice Quality. They lost almost 400,000 customers in the first Q. this year.

Then Telstra, then closing down their AMPS network, had the option of expanding their current GSM network, but due to poor RF performance and distance GSM will carry over the air opted for the CDMA standard. Even with boomer cells sites by ericsson the useable distance traveled ever the air for GSM does not meet CDMA, and GPRS can not be transmitted from the boomer cell sites.

KDDI, Just lunched the worlds first 3.3Megapixa camera running on their CDMA network.

I do not work for Telecom, I do not work for Vodafone.
I just know what is good, and Vodafone’s "Great and Flash" ads aside CDMA is the Technology of the future.

And the TX95C is a great phone. I have played with a number of them, and far better than the heavily customised GX-10 and other Vodafone live handsets.

Regards
Peter

JaBZ

404 posts

Ultimate Geek

#5841 19-May-2004 09:57

thanks skyplonk, exactly what I would've said!...
Remeber my argument was about the network, not number of users, flashy handsets, or marketing or advertising...

Even though Telecoms new handsets are great.. Unlike Vodafone advertising it's Sharp GX30 with it's 1.3 megapixel camera, GPRS cannot send the 1.3 megapixel pic at a decent enough resolution.
Telecom actually have a network that can transfer these types of pics to another phone. But remember my argument was about the Network!...

freitasm if you could please move the last 6 or so CDMA vs GSM/GPRS posts to the thread I created for this please...

My opinions and ideas expressed in posts are solely my own and do not reflect the views of my employer in any way..

rck

139 posts

Master Geek

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#5844 19-May-2004 11:10

GSM is based on the same sort of technology as the old 025 phones (minus the SIM card).
The biggest things going for the GSM phones is the SIM feature and the global standardisation of the networks.
The SIM function allows for easier phone portability, if you want to change your phone all you need to is change the SIM card instead of programming the phone with your number and reassigning the network allocation of number vs phone. This also allows for an easier target to thieves who want a new phone (and yes I do know that you can lock phones against new SIM cards but not everyone does that).
The global standardisation allows for phones to be developed for the GSM market regardless of which country ends up using it. Thus you can develop phones on a much larger scale since the market is much larger. This creates its own problems when a foreign phone is brought in and the customer expects it to be supported simply because it is active on the vodafone network. This is not always the case since the vodafone network may not have had any previous experience with that particular model in NZ yet. This standardisation has not had time to develop fully with the CDMA2000 1x network which telecom uses. There was the ability to customize the network to an operators individual requirements. This has resulted in a much smaller market for the phone developers who are making phones for the CDMA network. This issue is being continuously addressed and telecoms recent partnership with the US Sprint network is evidence of this, allowing the phone developers to create phones for a larger market creating higher demand and better phones. Companies like Nokia have now developed their own CDMA chips so do not have to rely on Qualcomm any longer for expensive chips and are able to develop the entire phone so future generations of phones should not have as many bugs.
In saying all that it cannot be denied that GSM uses an older not as efficient technology, voice and data are assigned to cell towers seperataly instead of together creating network configeration issues in high use areas. The phones have to use higher wattage to access the network, which is why vodafone phones interfere with speakers (If you're worried about radiation then that needs to be considered, not to mention the fact that it sounds horrible).
Voice quality declines signicantly in low signal areas so much that often you can only hear portions of what is being said with a staccato effect. This is to do with the way voice calls are allocated on the network, each call is assigned a time slot, split up and sent in that timeslot, if one section of that time slot is lost in transmission (which can happen in low signal areas) then you lose that portion of the voice call. Whereas with CDMA each call is assigned a code and the whole call is split up and sent with each portion. If a packet is lost is transmission then the volume may decrease slightly and thats it. Sort of like circuit-switched data compared to packet data

skyplonk

451 posts

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#5853 19-May-2004 14:13

CDMA we developed by the US and a version had limited use in WWII, but was not commercial put in to service until 1996.

GSM (021) and D-AMPS 025 (IS-136) are both TDMA standards, and the basic's principles are the same on both networks. Before the D-AMPS was a standard, the IS-54 standard toyed with the idea of a sim card design, but when the standard hit the market in early 90's in the states it was missing from the standard, which really resulted in slow uptake of the standard.

Vendors like Nokia, Ericsson and Motorola often made GSM and D-AMPS versions of their handsets because they did not require huge amounts of porting or R&D. The same antennas could be used as well as some of the RF equipment.

skyplonk

451 posts

Ultimate Geek

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#5876 19-May-2004 22:36

Well we are talking about GSM and CDMA

"AT&T To Offer Wireless Services To Consumers And Businesses Nationwide Through Agreement With Sprint"

"BEDMINSTER, N.J. - AT&T Corp. (NYSE: T) today announced that it has taken its first step in re-entering the wireless market by reaching an agreement with Sprint that will allow AT&T to sell AT&T-branded wireless service to its over 30 million business and consumer customers. As a result of the five-year agreement, AT&T expects to significantly expand the wireless services it is currently testing in select U.S. markets with hopes of a launch later this year.

"In a world where customers increasingly desire the flexibility of mobile communications, we are confident that they will want to buy AT&T wireless services from one of the most trusted names in communications," said AT&T Chairman and CEO David W. Dorman. "AT&T has proved it is capable of rolling out bundles of new and complex services quickly and cost-effectively, with top-notch customer service, and we are excited to have this important capability that will help us better serve customers."

"We are delighted that AT&T has expressed their strong vote of confidence in the performance and capabilities of our nationwide CDMA network," said Len Lauer, Sprint's President and COO and President of Sprint Consumer Solutions. "We believe this agreement provides substantial positive benefits for both of our companies and we look forward to serving AT&T's wireless communications needs. "

Sell their GSM netowrk, and pick up the use of a CDMA network.... What more can i say!

http://www.att.com/news/item/0,1847,13067,00.html

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freitasm

BDFL - Memuneh
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Geekzone

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#5891 20-May-2004 08:03

Hello... This is a friendly warning

.

I've transferred the discussion to this thread on request, because it was off topic on the original thread. Feel free to discuss this topic at will. Just keep this non-personal and do not involve company names in specifics (like in operator A is better then operator B), and the thread will be open forever.

Otherwise, fight over your standards.

skyplonk

451 posts

Ultimate Geek

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#5898 20-May-2004 09:04

Well the 3 biggest GSM networks in the states have some of the highest churn rates in the states ... Higher than most Iden and CDMA networks...

freitasm

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#5900 20-May-2004 09:07

That's probably because of spotty coverage. And that's why AT&T Wireless is deploying 850MHz, to try and cover larger areas..

Actually we have a local problem with coverage too, in smaller scale.

rck

139 posts

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#5927 20-May-2004 18:51

Johnr, I was referring to the fact that both 025 and GSM were based on TDMA, I do realise that there is a larger difference than a simple SIM card. And what is cause for the radio interference then?
I was however highlighting the fact that the SIM was a major advantage for GSM.
Both networks have their advantages and disadvantages.
Take data for instance. Currently it is not in huge demand, however, for people who require it for field work can GPRS or 3GSM reallly accomodate them?
Voice coverage with GSM only is on par with 027 (both networks have patches where one netowrk gets coverage and the other doesn't but in the end it balances out) but...
GPRS cannot be accesed wherever GSM can be accessed. Speeds drop from around 60-70kbps maximum to less than most faxes, pricing also goes from being calculated on data transfered to time used in GSM only coverage. And 3GSM is going to be even worse, ~70% of NZ covered by 2009, initially only a portion of auckland and wellington.
On the other hand is 027 mobile jetstream which is available where ever 027 coverage is available and reaches speeds of 130kbps+ on regular occasions, averaging out at around 80-100kbps and reaching upto 153kbps.
If you were a business with staff in the field (often in remotish areas) requiring access to company files or databases for critical business situations which would you rather go for?

Jama

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#5954 21-May-2004 12:33

Interesting thread some correct some incorrect information...

1. CDMA was not invented in the '40's. Spread Spectrum radio (the technology CDMA uses) was. Believe it or not spread spectrum was invented by the actress Hedy Lamarr as a method to stop the Germans from jamming the radio signal on torpedoes.

2. 11:30am - Data test - 500Kbyte PDF
CDMA Gtran - average speed 123kbps
Voda card - average speed 33kbps

...you do the math.

3. Fact - coverage is better on CDMA. A CDMA cell site can cover a radius up to 150km. Where as a cell site on GSM is up to 37km (unless there is double slot which offers coverage up to 90km but reduces capacity). In parts of Western Australia your GSM phone will have signal strength but you can not place a call because of reduced capacity.

4. Fact - Rel99 or Release 99 of UMTS (which Voda are likely to role out) will have a basic data rate of 64kbps. Because they are using a frequency up in the 2GHz range they will need 3 times as many cell sites as they have now to offer this basic data rate. The physics of radio propagation apply.

5. Fact - its not just about speed it is also about latency. Average latency on GPRS is around 1.3 seconds, on CDMA it is around 400milliseconds. This is sending a 32 byte packet over the internet.

6. Fact - In terms of data transfer GPRS only supports the UDP protocol which does not natively have error correction. Try driving around whilst sending data on GPRS, if you go out of coverage you will have to resend all the data. CDMA supports UDP and TCP, with TCP if you go out of coverage the network will request the last known good packet rather than having to start again.

....I have tried this myself, several times.

7. Fact - Voda rely on NAT or Network Address Translation. This means a GPRS phone/card on a data session is assigned a Private IP address and then a proxy manages the translation of requests to external networks (internet). On Telecom CDMA each data user is assigned a public IP number - no proxy and no NAT.

...Ask your local IT integrator which method is easiest to work with

Any other questions?

Kickass

292 posts

Ultimate Geek

#5955 21-May-2004 13:31

CDMA is better, but the lack of good handsets really put it down.

i changed to vodafone , beuase they have better handsets , and MMS to other 021.

within a few years if CDMA picks up , i will go back on CDMA

also Sim cards are very handly :)

Sam

JaBZ

404 posts

Ultimate Geek

#5956 21-May-2004 14:08

>CDMA is better, but the lack of good handsets really put it down.

There are good handsets for CDMA, not all necessarily in NZ, they are equivalent to GSM handsets.

NZ MMS ones..

Hyundai TX 95C (takes better pics than the Motorolla V525 GSM)
Nokia 6225 exactly the same as the Nokia 6220
Sanyo 8100

>i changed to vodafone , beuase they have better handsets , and MMS to other 021.

You may not be aware though Telecom do have MMS capable handsets that MMS to 027, See above

My opinions and ideas expressed in posts are solely my own and do not reflect the views of my employer in any way..

skyplonk

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#5957 21-May-2004 14:25

And more MMS handsets to come in the next month or so
More examples by Nokia, Kyocera and Hyundai. I hear a Motorola might be coming, not to sure of that yet..

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