WCDMA v. HDSPA v. UMTS
 

I know a WCDMA 2100 phone is needed to work in Japan. I read on a couple web sites that HDSPA is an advanced version of WCDMA and is backwards compatible with WCDMA.

My question is: Is a HDSPA 2100 phone usable in Japan?

Am I correct in stating that all WCDMA phones are UMTS but not all UMTS phones are WCDMA?

Thanks for any light someone can shed on this.

...mike

1- yes, because hsdpa on umts as like as edge on gsm network

2- no, wcdma is the core technology of the umts, so is pratically the same to say wcdma phone or umts phone
(read http://www.gsmworld.com/technology/3g/faq.shtml )

WCDMA is an interface between the phone and the network.

The first generation of WCDMA phones used UMTS.

The second generation uses HSPA, which permits faster data transfer. It is backwards compatible with UMTS.

All WCDMA networks to my knowledge support UMTS. Only some support UMTS.

If you get a device that supports UMTS but not HSPA, you will be able to use 3G WCDMA networks but those that support HSPA will only work for you at UMTS speeds. If you use an HSPA phone on a UMTS network that doesn't support HSPA, again your phone will work but you will not get the maximum speed your phone can handle.

If you need HSPA where it's available, get an HSPA phone. If you don't, a UMTS phone will suffice. For voice, the difference is nil. It's only a data issue.

Is there any difference in the SIM between UMTS and HSPA? I've seen people selling HSDPA SIMS but wondered if this was just marketing and they're the same as UMTS. By analogy that no special SIM is needed for EDGE.

Can't really answer your question, however I'm aware of one SIM card that works in HSDPA/HSUPA devices but doesn't in UMTS devices.

Speed :)

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[via HSUPA, qualcosa si muove] <!--post-->

WCDMA is the designation of a multiplex technology describing the way data is radio-transmitted.

WCDMA is used in several mobile communication standards, which are namely FOMA, UMTS-FDD/HSPA and UMTS-TDD.

FOMA is an early 3G-standard, which was only used in Japan and was very similar to UMTS-FDD. After UMTS-FDD was standardized NTTDoCoMo, who were the only operator of a FOMA-network, switched their whole network to UMTS-FDD. So FOMA is dead today.

WCDMA is often used synonymously for UMTS-FDD, but actuallty UMTS-FDD is just one standard using WCDMA. However since UMTS-FDD is the major 3G-standard worldwide, it is often refered to as "UMTS" or "WCDMA".

UMTS-TDD, which is incompatible to UMTS-FDD has been deployed in very few places and isn't marketed as "UMTS" anywhere, afaik.

So all in all when you read "WCDMA" or "UMTS" people mean "UMTS-FDD".

HSDPA is an enhancement of UMTS-FDD providing [B]download[B] bandwidth of up to 14.4 MBit/s instead of only 384 KBit/s.
HSUPA is another enhancement of UMTS-FDD providing [B]upload[B] bandwidth of up to 5.76 MBit/s instead of only 384 KBit/s.
If a device supports HSDPA and HSUPA it is called "HSPA", which is kind of needless, since all HSUPA-devices support HSDPA. So talking about "HSUPA" implies HSDPA-support.

HSPA has been subject to improvements raising download bandwidth to more than 14 MBit/s, which is then called HSPA+. Australian operators even plan to provide 42 MBit/s by the end of 2010.

HSDPA/HSUPA/HSPA is basicly still UMTS-FDD with the ability to reach higher speed by improved modulation. So both are fully compatible. So a HSPA-device will work on a UMTS-only-nework and a UMTS-only-device will work on a HSPA-enabled network, however in both cases speed will be limited to 384 KBit/s.

Besides this question of standard you should bear in mind, that many frequency bands are used for UMTS and only very few devices support more than one frequency band.
Whereas Europe, Oceania and Asia mostly operate UMTS at 900 and 2100 MHz, American UMTS-networks work at 850, 1700 and 1900 MHz. Afaik there is still no device available supporting all these five UMTS-bands, so it's impossible to have a worldwide compatible UMTS-device, whereas that's possible for GSM by buying a quadband-phone.
For a complete list of UMTS-bands see: UMTS frequency bands - Wikipedia, the free encyclopedia

Forgot to mention, that HSDPA is also called 3.5G and HSUPA/HSPA 3.75G.

UMTS-TDD is used in only 20 networks worldwide: UMTS TDD Alliance :: Deployments

@AndreA
Why have you set up such a short timelimit for alterations? I think one whole hour would be better.

No, there are no special HSPA-SIM cards. There is only a difference between plain GSM-SIMs and UMTS-SIMs (so-called "USIMs"). Wether a subscriber may use HSPA on a UMTS-network or not depends on what's defined in the HLR.
The main difference of GSM-SIMs and USIMs is the authentification-methods, since these differ between GSM and UMTS. However you can still configure UMTS-networks to accept GSM-autentification. Therefore in Germany you can access the T-Mobile and Vodafone networks even with ancient GSM-SIMs, whereas eplus and O2 insist on UMTS-authentifiation, so their customers need a USIM to register on the UMTS-networks. Since this is a question of network configuration a eplus/O2 subscriber with GSM-SIM can theoretically still access foreign UMTS-networks while roaming, as far as GSM-autentication is accepted.
Besides this relevant difference USIMs usually have higher memory capacity.

That's true. Anyway I'm loving my upload speed :D

Some people like to complain that there are no phones to permit access to all possible WCDMA bands. My response is "¿Por Qúe?" What would one do with such a phone? Do you have a roaming plan or pockets deep enough to allow gigabytes of data usage while roaming? When I got the Nokia e61 I decided I could rest in my search for my roaming phone. I think back to the days when I traveled with two Nokias: a 2110 and a 2190, one battery, one charger and one belt case. I thought that was pretty efficient.

My data stick is quad-band GPRS/EDGE (850/900/1800/1900), tri-band UMTS/HSDPA/HSUPA (850/1900/2100). That's close.

We can pick on Europe a bit. If I recall correctly, there is still some Scandinavian coverage with GSM at about 450 MHz. I've never seen any phone that supports these frequencies.

1700 MHz spectrum is just being deployed here in Canada, and 700 MHz spectrum has been auctioned in the US and will be available for cellular deployment as soon as analog TV broadcasting is turned off in the USA. Canada will follow by a couple of years.

The only reason we can get every 2.5G GSM frequency on a device is that the world has stopped adding 2.5G GSM frequencies. There are no GSM radios that do 2.5G at 1700 MHz or 2100 MHz, so there's no need for phones to support those modes.

On the one hand multiband support is nice if you buy local SIMs and so affordable data tariffs and on the other hand there are networks like Telstra's in Australia, which have a far better 3G-coverage than 2G. Just compare these two coverage maps:
UMTS850: GSM Coverage Maps | Australia | Telstra Corporation Limited (Telstra MobileNet) | Coverage Map (it's UMTS850 only, despite the map description says "3G 850 + GSM")
GSM900/1800: GSM Coverage Maps | Australia | Telstra Corporation Limited (Telstra MobileNet) | Coverage Map

If you further compare Telstra's UMTS850 coverage to the GSM coverage of Telstra's competitors...
GSM Coverage Maps | Australia | Vodafone Pacific Limited | Coverage Map
GSM Coverage Maps | Australia | Singtel Optus Limited (YES OPTUS) | Coverage Map
...you see that with a UMTS850-phone you'll get the best coverage in Australia by far.

Another advantage of UMTS is, that those networks have higher capacity, which has often allowed me to place and receive calls, when 2G networks were congested (especially during holidays or events).

I thought it was actually CDMA2000 that's deployed on 450 MHz for cheap Internet. It is deployed in about half a dozen countries though. Mostly former NMT countries.

DRNewcomb, ever thought of when 2G/GSM will be expired? We would then certainly need a device that supports all the UMTS bands in use. I see operators that are now deploying 3G on 900 MHz soon starting to cut down on 2G in that band. I guess progress has to happen at some point. We can't keep 2G around forever. Backward compatibility is why devices cost more to make every time a new band is added. I used to be in the camp of keeping the older services running back when it was just one or two bands used for 3G (2100 & 1900) but now it's just getting out of hand. We need to move forward. Sure lots of 2G devices will cease to function once 2G gets turned off but wouldn't they be obsolete anyway? Honestly, how many here regularly use phones over 7 years old, let alone phones that were out since GSM was 1st deployed (10 to 15 years now depending on country)?

Sorry for the rant. I'm going to miss my 2G devices like anyone else but I'm excited for the future of mobile development and keeping backward compatibility is affecting progress.

There are lots of devices that are less than 7 years old that don't support any 3G frequencies.

In fact, if 2G were to shut off tomorrow, I only have two devices that I could use: my iPhone 3G, and my Sony-Ericsson K610i (and the latter, only if I were somewhere that supports UMTS 2100).

That happens when a carrier has lots of 900 MHz spectrum and not enough 2100. The big problem with UMTS is that it takes 5 MHz per RF channel and a cell needs two channels (10 MHz). While you can build a 2nd rate network with just 10 MHz (one cell "color"), to build a proper system requires 30 MHz (3 "colors"). That's a lot of bandwidth. Many 1900 MHz systems in the US are built on 10 MHz licenses.

I see the replacement for 2G as being something other than UMTS. I understand that the standard actually allows channels less than 5 MHz.

You seem not to know a basic difference between GSM and UMTS: While in GSM-networks neighbouring cells must use different channels to avoid interferences and so the "Four color theorem" must be observed, in UMTS all cells use the same frequency. So 2 x 5 MHz (5 MHz for the uplink and 5 MHz for the downlink) is enough for a continious network. Of course you can add additional capacity by running a second UMTS-carrier on separate 2 x 5 MHz-channels.
In Germany all the 4 active operators have just 2 x 10 MHz in the 2100 MHz-band.

Yes, but the use of a single channel increases the noise floor and reduces the system capacity and data rate. Which is why I said "2nd rate". With GSM systems, cochannel interference will really mess things up. With CDMA it slowly degrades the system. A cumulative effect. UMTS-TDD avoids this problem by time-slicing everything.