View Full Version : WCDMA and 3G
WCDMA is 2100 Mhz but 3G is 1900 Mhz right. What the different between these two technology for the data transfer bandwidth?
Box215
03-06-2005, 09:45 AM
No, they are the same thing.
Michael
03-07-2005, 02:30 PM
ThanksWCDMA is a 3G technology. But WCDMA and 3G are not the same thing. CDMA2000 1xRTT/EV-DO/EV-DV are 3G technologies, as is TD-SCDMA. WCDMA is just one of many 3G technologies defined by the 3GPP.
carcomptoy
03-07-2005, 08:21 PM
What's TD-SCDMA...I've never heard of it
gromitjc
03-07-2005, 09:19 PM
It stands for Time Division Synchronous Code Division Multiple Access - it's a 3G technology that's being pushed in China.
carcomptoy
03-07-2005, 11:02 PM
So it's a hybrid of TDMA and CDMA? Weird...does it use some sort of SIM card or no?
carcomptoy
03-08-2005, 12:09 AM
I just realized this...two things that are the same are UMTS and WCDMA, right?
Michael
03-08-2005, 05:22 AM
Right. I believe UMTS was a name conceived by the European Union for the 3GPP WCDMA spec.
gromitjc
03-08-2005, 08:17 AM
I just realized this...two things that are the same are UMTS and WCDMA, right?
WCDMA and UMTS are not synonymous (if that's what you meant).
jmax577
03-08-2005, 01:21 PM
but umts and foma have different standards
gromitjc
03-08-2005, 01:43 PM
Yes - UMTS and FOMA are completely different technologies that happen to both operate over WCDMA.
Michael
03-08-2005, 02:44 PM
Yes - UMTS and FOMA are completely different technologies that happen to both operate over WCDMA.I think that is overstating the truth a bit, considering that current UMTS and FOMA handsets can now roam onto each others' networks.
It is true that FOMA in the past has varied a bit from the WCDMA standard as defined by the ITU, but that is no longer the case to the best of my knowledge. FOMA originally made use of UMTS release 99, but now uses the same version that 3G in Europe uses.
jmax577
03-08-2005, 03:10 PM
I think that is overstating the truth a bit, considering that current UMTS and FOMA handsets can now roam onto each others' networks.
It is true that FOMA in the past has varied a bit from the WCDMA standard as defined by the ITU, but that is no longer the case to the best of my knowledge. FOMA originally made use of UMTS release 99, but now uses the same version that 3G in Europe uses.
wow. i said that like a month ago and i was quickly struck down by numerous members here telling me i was wrong. :mad:
gromitjc
03-08-2005, 04:41 PM
FOMA and UMTS handsets can't roam on eachother's networks. They're unrelated, and not at all compatible. Only FOMA handsets that support GSM can roam outside Japan. FOMA technology and the WCDMA air interface were developed concurrently by NTT DoCoMo. WCDMA was later selected as the air interface for UMTS.
The WCDMA article from Wikipedia expains it reasonably well:
http://en.wikipedia.org/wiki/W-CDMA
jmax577
03-08-2005, 07:41 PM
FOMA and UMTS handsets can't roam on eachother's networks. They're unrelated, and not at all compatible. Only FOMA handsets that support GSM can roam outside Japan. FOMA technology and the WCDMA air interface were developed concurrently by NTT DoCoMo. WCDMA was later selected as the air interface for UMTS.
The WCDMA article from Wikipedia expains it reasonably well:
http://en.wikipedia.org/wiki/W-CDMA
:confused: i give up
Michael
03-08-2005, 07:47 PM
FOMA and UMTS handsets can't roam on eachother's networks. They're unrelated, and not at all compatible. Only FOMA handsets that support GSM can roam outside Japan. FOMA technology and the WCDMA air interface were developed concurrently by NTT DoCoMo. WCDMA was later selected as the air interface for UMTS.
The WCDMA article from Wikipedia expains it reasonably well:
http://en.wikipedia.org/wiki/W-CDMARight you are. I mis-remembered a NTT DoCoMo release from last year. The roaming is handled by putting the foreign SIM into a FOMA phone or a FOMA SIM into a foreign phone (when outside of Japan).
Here is the Wikipedia entry for UMTS (http://en.wikipedia.org/wiki/UMTS).
Vodafone Japan (formerly J-Phone, I believe) does use UMTS and is what allows for roaming into Japan using european UMTS handsets.
My bad.
jmax577
03-08-2005, 08:05 PM
sheesh!
carcomptoy
03-08-2005, 11:39 PM
Well, either way, not like I'm gonna have a UMTS or FOMA cellphone in the near future. Kinda depressing just thinking how I'm not gonna be able to have either...I want to visit Japan so much! Just to experience the awesome mix of technology with tradition!
Dynamoo
03-09-2005, 09:01 AM
Vodafone Japan (formerly J-Phone, I believe) does use UMTS and is what allows for roaming into Japan using european UMTS handsets.
Hence the Sharp 902 which is sold in Europe and Japan, along with a handful of other handsets.
All UMTS handsets in Europe and I guess worldwide will roam onto GSM anyway. I don't know much about FOMA, but I guess at least some of those roam onto GSM too. GSM is the common factor.
On problem though.. a lot of UMTS/3G handsets are only dual band 900/1800 GSM devices with only a handful being GSM 900/1800/1900. I certainly don't know of any quad band 3G phones.
Michael
03-09-2005, 09:47 AM
All UMTS handsets in Europe and I guess worldwide will roam onto GSM anyway. I don't know much about FOMA, but I guess at least some of those roam onto GSM too. GSM is the common factor.
On problem though.. a lot of UMTS/3G handsets are only dual band 900/1800 GSM devices with only a handful being GSM 900/1800/1900. I certainly don't know of any quad band 3G phones.A UMTS phone doesn't have to support GSM, though. Most just do because it isn't practical to rely purely on the UMTS networks currently.
carcomptoy
03-09-2005, 10:46 PM
Hopefully though, UMTS will finally bridge the gap between the Americas and Eurasia (if the carriers can obtain licenses for 2100MHz)...then we'll finally be able to use phones like the unique Nokia 7600, although I've heard it's not a good phone. Still, it's unique and different...and funky just the way I like phones:D
jmax577
03-10-2005, 09:52 AM
i got word today from my superior that us in the wichita market have a umts launch meeting next tuesday. this is very much becoming a reality now, cingular normally keeps their mouths shut until they have a solid plan in place. umts here we come!
carcomptoy
03-10-2005, 08:37 PM
Any way you can post during the meeting?:p
jayesh
03-10-2005, 09:41 PM
Hopefully though, UMTS will finally bridge the gap between the Americas and Eurasia (if the carriers can obtain licenses for 2100MHz)...then we'll finally be able to use phones like the unique Nokia 7600, although I've heard it's not a good phone. Still, it's unique and different...and funky just the way I like phones:D
you do have the the 6630 and the upcoming 6680 :D too use on umts :D
carcomptoy
03-11-2005, 12:05 AM
Well, yeah I know, but I'm pointing out the 7600 because w/o UMTS we wouldn't be able to use it, whereas the 6630 and 6680 can be used because it is tri-band...
jayesh
03-11-2005, 05:42 AM
Well, yeah I know, but I'm pointing out the 7600 because w/o UMTS we wouldn't be able to use it, whereas the 6630 and 6680 can be used because it is tri-band...
no u can it works fine .. its a dual band gsm fone too 900/1800 works fine
carcomptoy
03-11-2005, 06:47 AM
Works fine in Europe and Asia, but what about US?:cool:
exactly, US doesn't use 900 or 1800, only 850 and 1900, hence the only way to use a 7600 would be 3g.
jayesh
03-11-2005, 11:09 PM
oops my bad... i missed that point :)
i dont think it would work anytime soon in the states too .. 3g has been sanctioned i believe in the 1900 band? Correct me if i am wrong ...
gromitjc
03-11-2005, 11:16 PM
Cingular is operating UMTS on 1900MHz for now, but it needs 2100MHz too if we're going to be compatible with the rest of the world,
carcomptoy
03-12-2005, 01:36 PM
Btw, do you know anyone who is actually using UMTS here in the US from the trial runs?
gromitjc
03-12-2005, 04:27 PM
No, can't say I do. The test markets are Seattle, San Francisco, San Diego, Phoenix, Dallas, and Detroit. The Cingular/AT&T UMTS site is http://www.attws.com/umts
carcomptoy
03-13-2005, 10:43 PM
Why is it that you can't use any other phone but the two crappy ones they provide? I heard that you can't use any other phone but those two on Cingular/AT&T UMTS even if it's 3G...
gromitjc
03-13-2005, 10:55 PM
Why is it that you can't use any other phone but the two crappy ones they provide? I heard that you can't use any other phone but those two on Cingular/AT&T UMTS even if it's 3G...
That's right - you can't use any other UMTS phones because they require both 1900MHz, and 2100MHz, and the latter isn't available here (yet). The phones that Cingular/ATTWS offers were developed specifically for the North American market and use UMTS on 1900MHz only. Aside from UMTS 1900 the Motorola A845 also does GSM 1900/1800/850 but the Nokia 6651 only only has GSM 1900 to fall back on.
carcomptoy
03-13-2005, 11:02 PM
It's so dumb too...it says
* Connection to another device or computer via cable, Bluetooth, or infrared will be charged $0.001/KB.
* You also will be charged $0.001 per KB if you remove the SIM card from your phone and use it to get wireless data service from another device or computer.
If they're not already impairing you, it's additional handicaps!
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