中文摘要：

在LTE部署的初期，LTE网络覆盖范围有限，因此会经常发生网络的切换；为了保证通话的连续性，于是引入了SRVCC，而SRVCC切换配置使用A2＋B2事件触发；研究显示：虽然SRVCC在不同的门限下业务表现差异较小，但是B2RSRP1门限降低时切换成功率会恶化，通过对比分析，为VOLTE将来在不同环境下SRVCC的参数设置提供了参考。

英文摘要：

In the early stage of LTE deployment, LTE network coverage is limited, as a result, the network often switches. In order to ensure the continuity of the call, SRVCC is introduced, and SRVCC switching configuration uses A2＋B2 event to be triggered. The research shows that although SRVCC has small difference in business performance with different thresholds, the switching success rate is worse when B2 RSRP1 threshold is reduced. By comparative analysis, this paper provides the reference for SRVCC parameter setting of VOLTE in different environments in the future.