On Jul 29, 2011, at 1:31 PM, Jim Warthman wrote: > Perhaps this discussion of standards would be simpler if we separate voice > and data.
Not particularly. UMTS is used for voice and data, GSM is used for voice and data. W-CDMA is actually one of the UMTS standards - the first. Higher speed UMTS devices like the iPhone support HSUPA and HSDPA versions of UMTS. UMTS is a more accurate acronym, *and* doesn't suffer namespace collision issues with CMDA2000/EVDO. :) One of the biggest causes of confusion is that CDMA used to describe both a modulation type *and* a specific protocol that uses it. eg: FM means "Frequency modulated". When people say FM Radio they usually mean the broadcast standard that runs from ~88 to 108 MHz, using I think 100 kHz wide carriers. My ham radio uses FM too - but 5 kHz wide, at around 144 MHz and 440 MHz. Qualcomm invented the CDMA modulation type, *and* they designed a protocol that used it, *and* they built chipsets for it. So: people frequently use CDMA to refer to a specific Qualcomm protocol. IS-95, 1xRTT, EvDO, CDMA2000 etc. are various Qualcomm CDMA standards. Thanks, gopi. _______________________________________________ iPhone-talk mailing list [email protected] http://www.omnigroup.com/mailman/listinfo/iphone-talk
