说明：  文章根据WiMAX的特点，详细分析了802.16d和802.16e中常见的安全策略，介绍了关于WiMAX的IMS应用，特别是VoIP的安全问题，并讲述了WiMAX中端到端的安全策略，最后指出了现有安全策略的不足和改进方向。
(The article in accordance with the characteristics of WiMAX, a detailed analysis of the 802.16d and 802.16e common security policy, information on the IMS Application of WiMAX, especially VoIP security issues, and described in WiMAX end-to-end security strategy, and finally pointed out that the current there is insufficient security strategy direction and improving.)