Techs & Trends

SPCSVZWJeff said:

We see WCDMA not as an adoption of the GSM platform but the full on surrender of the GSM community to the superior air interface of CDMA.

That's because you don't have a true grasp of the technology. "surrender of the GSM to cdma"? Nonsense. UMTS uses TDMA or FDMA overlays depending on what type of UMTS. GSM uses both as well. No "surrender" there. GSM has NEVER meant sticking to one idea only. GSM has been about openended standardization. UMTS is compatible with current GSM networks. THAT'S why they chose it as the successor to current GSM technology. If ANYTHING they decided to "surrender" to WIDEBAND technologies instead of narrowband. Something that CDMA operators REFUSE to do for...
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So GSM migrated from narrowband to wideband, and that's not surrendering. Why, if/when CDMA migrates from narrowband to wideband is it then surrendering?

You are misquoting me. I said GSM did not surrender to CDMA... I specifically said that GSM surrendered to wideband. ITU has already tried to convince CDMA carriers to go wideband for 3G. Vodaphone also tried to convince VZW to go wideband. Now they have to wait for 4G to get into wideband... and it will be a surrender to that technology. Something that GSM saw coming several years ago...

Ok. Great. GSM has moved over to spread spectrum code division, something that CDMA has been about since its inception.

CDGIII said:
Ok. Great. GSM has moved over to spread spectrum code division, something that CDMA has been about since its inception.

And something CDMA has never been able to get right. GSM picked the CORRECT way... CDMA picked the faster way...

Never able to get right? Given the perfectly orthagonal nature of Walsh Codes, you either get it right or you do not. There is no middle ground. Something GSM could never understand.

When I spoke of the GSM community surrendering I only meant surrendering to a Code Division Multiple Access air interface. UMTS uses a CDMA air interface in order to achieve its objectives.

And let's clear something up. Many carriers in Europe asked their regulatory bodies to allow them to use CDMA. Their regulators denied the request and instructed them to come up with a homegrown European system. UMTS is more about the EU's protectionist policies than it is about an open ended system.
The FCC to their credit has never forced a standard, good or bad on the American people for wireless service. If they had then the whole GSM/CDMA debate would be moot.
The CDMA air interface is the result of Ericsson's acquisition of a Qualcomm patent...
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Just some good info from a good source over at HoFo. CDMA2000 will always have a lower spectrum usage. On a side note WCDMA was not made for GSM. In Japan NTT went from PHS to WCDMA they never had GSM. CDMA could also go to WCDMA if they want instead of going to EV-DO/ EV-DV

in 2004:
edge at 118kbps and 235kbps
1xrtt at 153kbps
in 2005:
wcdma at 384kbps
ev-do at 2.4mbps

in 2006-07:
wcdma with hsdpa at 4.6mbps
2xev-do rel a at 6.2mbps
2xev-dv rel d at 6.2mbps
1xev-do rel a at 3.1mbps
1xev-dv rel d at 3.1mbps

in 2007-08:
wcdma with hsdpa and mimo at ~14.4mbps
2xev-do and 2xev-dv with mimo ~12.4mbps

beyond 2008:
cdma2000 2xev-dv with 4 antenna mimo ~25mbps
wcdma hsdpa with 4 antenna mimo ~29mbps

2010 and beyond:
c...
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Hello2 said:
my responses in bold
Just some good info from a good source over at HoFo. CDMA2000 will always have a lower spectrum usage. On a side note WCDMA was not made for GSM. that's not true. UMTS was designed to be GSM's 3G upgrade path. NTT chose UMTS because it's better than CDMA2000. In Japan NTT went from PHS to WCDMA they never had GSM.true, but they chise the GSM 3G path NOT the CDMA path. CDMA could also go to WCDMA if they want instead of going to EV-DO/ EV-DV yes they could. The ITU recommended that they go with wcdma because narrow band technologies will ALWAYS be limited. Vodaphone also heavily recommended that VZW use UMTS instead of CDMA2000.

in 2004:
edge at 118kbps and

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Sprint is also providing for Sprint and I believe sprint will move to EV-DV after DO that has always been their plan to have DV not DO

I think you meant Lucent's providing for Sprint, and you are right. However, Sprint has paused on their plans to release ev-dv. #1 because ev-dv is not ready, and #2 because ev-do is actually gaining acceptance and working well. This is my whole entire point behind my argument: Lucent makes BOTH technologies. Lucent says UMTS/HSDPA will perform BETTER than CDMA2000/EV-DO. Ericsson sells both... they say the same thing. CDMA carriers have been sold mostly on the fact that CDMA is cheaper and faster to implement, giving them a head start. GSM/UMTS is more expensive and a little bit trickier to implement, but offers more potential than the competition not too mention had longer staying power.

The reason CDMA is a stronger choice is based on the fact that it needs less spectrum 1.25 MHz per carrier as opposed to UMTS and CDMA can run on the IMT band. I believe EV-DV is now in South Korea and is doing well.

Hello2 said:
The reason CDMA is a stronger choice is based on the fact that it needs less spectrum 1.25 MHz per carrier as opposed to UMTS and CDMA can run on the IMT band. I believe EV-DV is now in South Korea and is doing well.

Ok... let's start with Korea. South Korea is using ev-do from 2 out of the 8 South Korean carriers according to the CDG. No one is using EV-DV yet.

Ok...now the efficiency...
UMTS doesn't use WCDMA by itself. If it did, you would be correct in saying that CDMA is more efficient, but it doesn't so you can't. UMTS also uses FDD: Frequency duplexing. It uses a technique referred to as frequency hopping which splits the 5mhz channel into narrower frequencies. This allows for bett...
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EVDO is not practically limited to 500kbps. I test it every week, and every week it gets better and better. Last Friday, we had consistent data rates downloading 10Mb files 10 times and AVERAGED 810kbps.

And whereas you can't make a comparison between theoretical limits and practical results, neither can you compare EVDO which is launched and operational now to HSDPA which has not been launched yet. By the time it does launch, the entire wireless industry may look completely different. Compare what GSM/TDMA offers now compared with what CDMA offers now.

CDGIII said:
Compare what GSM/TDMA offers now compared with what CDMA offers now.

This is your argument? OK. Let's compare. EDGE offers faster data than 1xRTT. UMTS also offers faster data. EV-DO does offer faster data speeds than UMTS in the states. But you are also comparing VZW's EV-DO to ATT's UMTS. Lucent and Cingular's UMTS is a different creature. I've seen peak transfer rates hitting 1mbps in testing. But let's hold on just a sec... EV-DO, UMTS, EV-DV, and HSDPA aren't even comepletely here yet.... EV-DO is in 14 cities and UMTS is in 6 cities. So, by all means let's compare what's available today. EDGE is the FASTEST NATION-WIDE technology available today. And that's a GSM technolo...
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What is the theoretical limit for EDGE?

a little under 500kbps. no devices support this currently, however. Ericsson has an EDGE network that pulled off about 280kbps in a live environment recently...

And how widely deployed is the EDGE Ericsson system? Is that TMobile?

It's Tmobile's Hungary network that pulled that off... I don't know what version of EDGE was used tho. I am assuming rel 5.

I get decent EDGE performance... in good signal areas, I get 100 kbps on the average. That's using my Nokia 6230 as a modem. It's not blazing fast, but I can play online games using it.

That's about what 1X_RTT will get.

Yeah, but it won't go ANY faster than that. My phone has a 234 kbps limit. tho, it's only hit around 135.

If you're sitting in the middle of the least loaded sector about fifty meters away from the tower, you can get 125-130kbps, but just how likely is that going to occur? Not very.

maybe not, but 1xRTT won't hit that speed sitting 10 feet from the tower... honestly tho, I have about 3-4 bars of signal strength at my home and I clock around 100 kbps when I am on.

I was talking about 1X_RTT. That's how we test maximum throughput, and the typical data rates associated with as best a real-world RF environment as you could ever expect. But if you get any closer to the base of the tower, you'll actually get worse performance due to the azimuth (inclination) of the antennae on the tower itself. Since they are not omnidirectional antennae, they have a "sweet spot" that you have to be away from the base of the tower to get.

I don't know diddly about this stuff, but does this mean Cingular who has GSM is going to have to eventually switch to WCDMA and Verizon that has CDMA will be switching to WCDMA which is not that difficult for them but for Cingular it would be difficult??? Is that correct??

No. First, let me start off by saying that it is never easy to switch a network from one technology to another, not even if it's just an evolution of the existing infrastructure. However, given the natrue of spread spectrum technologies, Cingular can explore a whole new methodology for deploying their WCDMA system (UMTS) when in fact it launches. In UMTS, you don't have to plan for having two towers that are located side-by-side NOT using the same RF channels and time slots (other wise, a mobile could experience access collisions). In CDMA, you don't ahve to worry about that. So, for Cingular, it will allow their system performance engineers some degrees of freedom in how they deploy it over what they have currently done for their TDMA/GSM n...
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Wow... Cain never fails to impress me... I don't think i've ever seen anyone refer to fdma on these threads... even though I am fairly new to phonescoop...

CainMarko said:
Actually, I have read that the 4G migration for CDMA will be MC-CDMA which is also "wideband" CDMA... From what I have read, both "gsm" and "cdma" will be able to choose this path.

That's multi-carrier CDMA, which is kind of like CDMA 3x combined with OFDM. I think it's way too early to call that as the 4G technology for anything. It doesn't have any real momentum yet.

A year ago, the landscape was pretty clear for CDMA folks - EV-DV release D looked like the holy grail. Like always, Qualcomm was in control. But now people are paying less attention to Qualcomm, and EV-DV might not even see the light of day. Verizon (and Nextel) are now talking about ditching both 1xRTT and EV-DV alt...
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From what I gather, there is a smaller, but well backed firm that is currently in market-trials with a carrier for just that, VoIP networks with EVDO. Lucent is also working on a system that their CTO has estimated will be ready for market trials by end of 2006.

Just out of curiosity, T-Mobile seems to be so behind the times when it comes to data. They are still working on EDGE, while AT&T is rolling out UMTS.

Why is that?

I would switch to ATTWS/Cingular except that in my area, they have pretty bad coverage.

Will T-Mobile ever catch up? I'm just curious because I'm looking to the future and want to get an idea about where things MAY head. I know that no one can predict for sure, but and idea is always nice.

I'm going into the computer field, specifically video games, and knowing a little bit more about wireless data transfer rates will be extremely helpful.

Thanks in advance for any input.

thatguy_overthere said:
Just out of curiosity, T-Mobile seems to be so behind the times when it comes to data. They are still working on EDGE, while AT&T is rolling out UMTS.

Why is that?

Two reasons:

1. Old gear. When Cingular and AT&T WS overlaid their TDMA networks with GSM, they had to deploy all-new GSM gear. Since it was new, it was EDGE-ready (designed specifically to be upgraded to EDGE). T-Mobile's GSM gear is much older - designed before EDGE was even a thought. That makes it much more difficult and expensive for T-Mobile to upgrade to EDGE.



2. Limited spectrum. I don't think T-Mobile has enough spectrum to deploy WCDMA in most areas. I don't know where that leaves them as far as

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Thanks for the info, that clears up a lot. I wish that ATTWS had better coverage here, I'd go with them. Oh well.

Thanks again.

what would you say is the best camera phone out with the best resolution i work for sprint and have an audiovox PM-8920 with a 1.3 megapixel camera is there one that is better?

Hey Rich,

Funny you should mention available spectrum. You're point is dead on square, and already steps are being taken to overcome that, including the upcoming auction by 2Q05.

https://www.phonescoop.com/news/item.php?n=1001 »

Thanks!

they're still going to use that spectrum for narrowband technologies...