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umts/wcdma difference |
619
Joined: Jun 19, 2002
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From: if you dont like my posts, IGN
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confused w/ 3g
SE are producing umts while other phone brands are wcdma?
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wapt
Joined: Jan 10, 2003
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WCDMA and UMTS are about the same.
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619
Joined: Jun 19, 2002
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From: if you dont like my posts, IGN
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CDMA 3G Variants (in the IMT-2000 Family)
The primary CDMA variants that will be used in IMT-2000 3G networks are W-CDMA (Wideband CDMA) and cdma2000, which are similar but not the same, so that W-CDMA handsets will not work with cdma2000 handsets and visa versa.
W-CDMA (Wideband CDMA)
W-CDMA is the competitor to cdma2000 and one of two 3G standards that makes use of a wider spectrum than CDMA and therefore can transmit and receive information for faster and more efficiently. Co-developed by NTT DoCoMo, it is being backed by most European mobile operators and is expected to compete with cdma2000 to be the de facto 3G standard
UMTS (W-CDMA)
In Europe, 3G W-CDMA networks are known as UMTS (Universal Mobile Telephony System) another name for w-CDMA/3G services. Governments in the region held UMTS auctions for 3G licences netting $108 billion in 2000.
FOMA (W-CDMA)
Japanese giant NTT DoCoMo Inc brand name for 3G services is FOMA (Freedom of Mobile Multimedia Access). Based on the W-CDMA format, FOMA services for a limited number of users is to begin at the end of May, with full commercial services due in October 2001.
cdma2000 (See more on cdma2000)
Then there is cdma2000, the other 3G standard. It is the upgarde to cdmaOne. It can use of a wider spectrum than CDMA and therefore can transmit and receive information faster and more efficiently, making fast Internet data, video, and CD-quality music transmission possible. There are however new cdma2000 variants called cdma2000 1X, 1X-EV-DV, 1X EV-DO, and cdma2000 3X. They deliver 3G services while occupying a very small amount of current spectrum (1.25 MHz per carrier) as opposed to UMTS which requires completely NEW spectrum (hence the auctions).
That is why cddma2000 is considered slightly more technologically advanced than the competing W-CDMA standard. CDMA2000 is not constrained to only the IMT band; it is defined to operate in existing cellular and PCS spectrum as well as IMT spectrum, thereby maximizing flexibility for operators. Cdma2000 is expected to be compatible with with CDMA and GSM/TDMA networks so that GSM networks can "overlay" a cdma2000 network over their GSM networks
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govigov
Joined: Jul 30, 2004
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From: Back home - Cochin
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But you cannot use a umts in a cdma network. I started such a thread a while back.
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scotsboyuk
Joined: Jun 02, 2003
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From: UK
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@govigov
As far as I can gather UMTS is another name for one of the CDMA variants, in this case, WCDMA. I think what you mean is that UMTS (WCDMA) is incompatible with CDMA2000.
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OluYom
Joined: Oct 27, 2004
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From: Nigeria
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@scots: Kindly help me out here. Its slightly off-topic but still within the discussion. CDMA nets run on the 850/1900Mhz band; dont they? If so, tech speaking triband GSM sets can roam CDMA nets? Thanks for clarifying.
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govigov
Joined: Jul 30, 2004
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From: Back home - Cochin
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@scots, that is what i meant. My friend works in a mobile company. He says that there are interference fringes with cdma1x. More ppl are complainting of their gsm handsets over heating. This was found to be the matter. And ofcourse the indian airforce used the came width from 915mhz. That is very close to the 900mhz spectrum.
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HjJ
Joined: Jul 02, 2004
Posts: 185
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Quote:
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On 2005-01-02 18:21:32, AYA wrote:
@scots: Kindly help me out here. Its slightly off-topic but still within the discussion. CDMA nets run on the 850/1900Mhz band; dont they? If so, tech speaking triband GSM sets can roam CDMA nets? Thanks for clarifying.
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No, same frequency does not imply compatibility. GSM uses TDMA, which is a different technology.
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OluYom
Joined: Oct 27, 2004
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From: Nigeria
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@scots: Thanks. Have always wanted to be clear on that.
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scotsboyuk
Joined: Jun 02, 2003
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From: UK
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@AYA
As far as I am aware CDMA and GSM are not compatible, although I believe there are handsets that can work on both types of network.
@all
I found this rather interesting document from Ericsson promoting WCDMA.
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brix25
Joined: Aug 20, 2003
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From: Cape Town, South Africa
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@AYA... In North America GSM networks use the 850 and 1900 Mhz spectrum.
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OluYom
Joined: Oct 27, 2004
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@brix: Yes, but they run on TDMA (with the insight Scots gave). That should be why tri & quad band GSM sets can roam there, methinks. @scots: Can you name a couple of these cross-platform phones you referred to? Thanks.
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brix25
Joined: Aug 20, 2003
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From: Cape Town, South Africa
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@AYA... Correct me if I'm wrong but isn't TDMA just a fancy name for GSM?
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govigov
Joined: Jul 30, 2004
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From: Back home - Cochin
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Triband phones have 900/1800/1900 mhz when in north america, these phones use the 1900 band width. Dual band phones do not have these and hence will not work. (At least that is what me thinks) @brix, you are very wrong, there are 3 main technology in second generation phones. gsm, cdma, and tdma. None of these are intercompatible.
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OluYom
Joined: Oct 27, 2004
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From: Nigeria
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@govigov: Geting confused here. Maybe I missed something. Whatz the difference between GSM & TDMA?
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Posted: 2005-01-02 05:39
