In mobile telephony, 2.5G protocols extend 2G systems to provide additional features such as packet-switchedconnection (GPRS) and enhanced data rates (HSCSD, EDGE).
In effect, it is like a new connection setup for the switched user.
事实上，这相当于为切换的用户建立了一个新的连接。
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When a trusted connection user is switched, it resets all the connection attributes, including cursor with hold, isolation, bind options, codepage, and so on.