Dave,
<< Perhaps you could explain what "GSM based WCDMA" is? >>
Perhaps somebody else should <g>. This is not a term I use since I think it is somewhat an anachronism (existing before ETSI's formal announcement in January to adopt WCDMA as the air interface of UTMS and the ERICY, QCOM accord that followed). At some point in time UMTS, which features a CDMA air interface will be substituted, IMO. In the case of DoCoMO (signatory to GSM MoU but not so far as I know a CDG member) this will not occur until sometime after the initial launch of their "GSM based WCDMA" network.
CDG on their web site says: "W-CDMA is a name identifying the ETSI and NTT DoCoMo standards for third generation technology submitted to the ITU as part of the IMT-2000 3G process. This standard encompasses an air interface that uses the CDMA technique but it is not compatible as defined for both air and network interfaces with cdmaOne, cdma2000 or IS-136. The air interface specification is not compatible with GSM and therefore does not support evolutionary migration."
The above is a rather dated statement. W-CDMA (WCDMA) has become the terminology describing the WCDMA air interface of UMTS, rather than a technology in and of itself.
Although DoCoMo seems to remain committed to launch by March 2001 the network will not then be fully compliant with UTMS standards but "will ultimately be fully compliant with ETSI standards ... and they are even prepared to regress to make modifications in their network if necessary." They "are projecting, though, that this will not entail any hardware modifications; They "can cope with any changes through software modifications." Or so sayeth the Nokia website:
nokia.com
<< The 3G agreement between Ericsson and Q envisions backward compatibility with previous gen so that in theory anyway, GSM, TDMA, and CDMAone will all "run" on 3G.. >>
In theory UMTS, UWC-136, and cdma2000, will all be interoperable on 3G. UMTS is supposed to be backward compatible with 2G GSM. I do not think that it claims to be backward compatible with cdmaOne. Is cdma2000 going to be backward compatible with 2G GSM? Maybe it will be. Do you have any insight? Perhaps we have to wait until the final phase one specifications for all 3 flavors of 3G to be published to answer this question.
- Eric - |
