说明：  LTE enodeb切换理解文档。详细介绍的切换过程enodeb与用户之间交互的信令，enodeb与核心网之间交互的信令。对lte协议栈的理解到开发有重要参考价值
(The LTE enodeb switched understand document. The Description handover process enodeb signaling between the user interaction between the interacting signaling, eNodeB, and the core network. Understanding lte protocol stack to the development of important reference value)