The Difference Between 2G & 3G SIM Cards | eHow.comdeep16 said:albeit there is no such difference to a home user in between a sim and a usim,, there are some cryptological(security) and storage advancements in a usim but particularly nobody gets much benifit out of them...
in terms of attainable speed there is "no" benifits in using a usim.. same spd can be attained using a regular sim also...
this article says otherwise..
Constant Internet Connection
Unlike 2G, 3G technology uses Internet Protocol (IP) connectivity which is packet-based. This means that using devices with a 3G SIM card are always connected to the Internet.
Although it does not provide any citation to this claim.
I read through a couple of wikipedia pages related to this and although didn't understand much, i think that USIM might make a difference when it comes to UMTS/HSPA networks.
Wikipedia said:USIM (Universal Subscriber Identity Module) is an application for UMTS mobile telephony running on a UICC smart card which is inserted in a 3G mobile phone. There is a common misconception to call the UICC itself a USIM, but the USIM is merely a logical entity on the physical card. It stores user subscriber information, authentication information and provides storage space for text messages and phone book contacts. The phone book on a UICC has been greatly enhanced. For authentication purposes, the USIM stores a long-term pre-shared secret key K, which is shared with the Authentication Center (AuC) in the network. The USIM also verifies a sequence number that must be within a range using a window mechanism to avoid replay attacks, and is in charge of generating the session keys CK and IK to be used in the confidentiality and integrity algorithms of the KASUMI block cipher in UMTS. The equivalent of USIM on CDMA networks is CSIM.
Subscriber Identity Module - Wikipedia, the free encyclopedia
I will upgrade, or atleast try to , and post back here if the connection issues persist.