It would be cool if somebody actually implemented a system where we could move GSM SIMs to CDMA phones and vice versa so with one SIM or R-UIM you could use mobile phones from CDMA or GSM suppliers or networks but the odds of that happening I'd imagine are the same as the odds were of Betamax winning over VHS :-) ! [And yes I know that CDMA technology is used by 3G GSM!]

FROM Removable User Identity Module - Wikipedia, the free encyclopedia via email from David

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Removable User Identity Module (R-UIM), a card developed for CDMA handsets that is equivalent to the GSM SIM and 3G USIM except that it is capable of working in both CDMA and GSM phones and networks. It is physically compatible with GSM SIMs and can fit into existing GSM phones as it is an extension of the GSM 11.11 standard

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EMAIL FROM David:

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It seems that not only are R-UIMs the equivalent to SIMs, according to the Wikipedia article they're actually compatible with SIMs and can be placed into GSM phones:
http://en.wikipedia.org/wiki/Removable_User_Identity_Module
It can actually store provisioning information for both types of networks:
http://www.china.org.cn/english/BAT/109251.htm
http://www.cdmatech.com/products/ruim.jsp
Technically, the R-UIM is basically kind of like of an extension of a SIM card that is defined in the "GSM 11.11" standard:
http://www.ttfn.net/techno/smartcards/gsm11-11.pdf
http://www.3gpp2.org/Public_html/specs/CS0023-0.pdf
Perhaps the CRTC should simply say that all providers in Canada (regardless of the underlying network) must use R-UIMs?

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