Is Europe worried about CDMA carriers?

I might be wrong about this but......isn't 4G simply the natural progression or next step up from UMTS?

 

@ShoresGuy

I took a look at the Wiki 4G article and from I can see the matter is somewhat confusing. The IEEE's name for 4G is apparently "3G and beyond" which might suggest that it is a continuation of 3G. However, the article does mention various things, which indicates that 4G will be a seperate standard altogether.

4G will apparently use a different air interface from 3G. 4G is said to possibly use OFDM or OFDMA. Also 4G will use packet switching whereas 3G uses a mixture of circuit and packet switching.

The data transfer rates for 4G are also significantly higher than 3G; a 100 Mbit/s download rate whilst moving and 1 Gbit/s whilst stationary.

You can read the Wiki article here.

 

I vote for CDMA2000, it's backwards compatible. An original CDMA2000 phone (CDMAOne?) will work on a 1XRTT system as well as a 1XEVDO system.

WCDMA is not backwards compatible with GSM, you'll need a new phone.

TD-SCDMA - no comment, never heard of it previously.

 

@EdwardP

WCDMA handsets typically have GSM included (actually I'm not sure there are any WCDMA handsets, which don't feature GSM support).

 

First UMTS (3G) uses softswitches and packet data. As far as TD-SCDMA is a standard developed in China and is about to be rolled out there by the largest mobile company in the world (China Mobile). 4G standards haven't been set yet but OFDM is one method that is being looked at. As far as "backward" compatibility that's a non-issue because most people are upgrading phones all the time.

 

An original CDMA phone will work on CDMA only. It cannot use RTT or EVDO services. If this were possible we would be talking about "forward compatibility" and I haven't seen the first technology that can do that. In order to take advantage of the new upgraded network you will need a new phone, otherwise your phone will continue operating on the old network. What makes older CDMA phones continue working after a CDMA network is upgraded is that the network operator continues to offer the old CDMA 2G service in parallel. So in reality those old phones are not talking to EVDO or 1XRTT networks because they can't. If the phone was made before the technology was invented, then you can't use it on the new technology. If the operator of an 1XRTT/EVDO network decides to terminate CDMA One services on its network all CDMA One phones will stop operating and only devices capable of 1XRTT and EVDO will work.

I'm not sure what your concept of "backwards compatibility" is but no matter how you look at it, you can either say that both CDMA/CDMA2000 and GSM/UMTS are not backwards compatible or that both are backwards compatible.

If you say that you need a new phone to use UMTS, then the same holds true for CDMA2000: you will need a new phone too. If you don't get a new phone you will fallback on GSM/GPRS/EDGE or CDMA IS-95 respectively and cannot use CDMA2000 or UMTS until you get a new phone. For every progression of CDMA2000 you will need a new device to take advantage of the new network upgrade. For instance, if you have a 1XRTT phone, you can't use EVDO until you get a new phone. Same goes for UMTS, you cannot take advantage of HSDPA until you get a new phone.

In either case you can always fallback on the older technologies. If you have an HSDPA device, you can always fallback on plain UMTS, GPRS, EDGE or GSM. I don't know about you, but this is what I know as "backward compatibility". The same goes for CDMA2000. If you have an EVDO device you can always fallback on RTT or plain old CDMA.

 

I agree with you that I have never seen a "forwards compatible" technology. Certainly no handset with a 2G technology is "forwards compatible" with new technologies whether you are talking about GPRS, EDGE, 1xRTT, UMTS, EV-DO, or HSPDA. GSM will work on UMTS networks because these networks include legacy support in the form of different transceivers.

 

The first wCDMA handsets in use were on NTT DoCoMo's FOMA system. FOMA was then and still is the largest wCDMA provider in the world, and most of their handsets are single mode (wCDMA only). Most of FOMA's system is now UMTS compatible, as are most of their handsets. These handsets will work on 2,100 MHz UMTS networks elswhere in the world, but they are not backwards compatible on GSM, GPRS or EDGE networks, unless these networks have added UMTS hardware.

 

@Bugwart

Ah yes I forgot about FOMA, thank you for reminding me. DoCoMo never used GSM, hence, apart from roaming handsets, they would arguably be less likely to want it included.

 

So then it's highly probable that NTT DoCoMo will also carry UMTS 1900/850 capable handsets once the UMTS infrastructure in the US has established? I don't think Japan would pass up the opportunity to allow their tourists to use UMTS in North America.

 

@ShoresGuy

That's an interesting question. I suppose we can break it down to two main possibilities; either DoCoMo includes support for North American UMTS in its range of handsets or it rents out handsets to its customers travelling to North America.

If DoCoMo does include support in its handsets then one also has to ask to what extent. It could be the case that it is limited to a few handsets aimed at people who travel to America frequently or it could be that DoCoMo includes support in all its handsets. DoCoMo's decision will probably be influenced by the state of UMTS in North America. If UMTS is not sufficiently widespread then Japanese visitors to North America would arguably need GSM support too and since DoCoMo hasn't supported GSM in the past I doubt they would bother now.

As UMTS becomes more widespread in North America I think there will be a better chance of DoCoMo offering native support in its handsets.

 

My guess is that DoCoMo will probably ensure that they get in good with AT&T again. After all, they partnered with the old ATTWS to setup the first 4 UMTS markets in the US a couple years ago.