基于DSP的电力VOIP系统嵌入式安全终端设计

Design of Embedded Security Terminal in Electric Power VOIP System Based on DSP

为实现电力VOIP系统的安全通信,确保电力调度的语音、视频图像的可靠传输,设计了一种基于DSP的电力VOIP系统安全终端。该安全终端由软件系统和VOIP安全通信平台组成;在硬件设计上,以OMAP-L137DSP为核心处理器,用安全芯片、噪声源芯片等辅助处理器实现系统的密钥算法,采用智能卡认证机制确保用户身份的合法性。在软件设计上,给出了电话模块与安全模块之间通信的数据帧格式,介绍了系统的流媒体交互方式,提出了一种基于身份签名的通信双方双向认证的密钥协商算法。通过系统测试表明,该VOIP安全终端的数据处理速度为52.312Mbps,满足电力系统实时调度通信的要求;密钥协商阶段平均耗时627ms,明码通信与加密通信的转换效率高;多台终端间网络视频通话的声音清晰逼真,画面无明显失真;该系统可扩展性和可移植性强,具有很好的应用推广价值。

In order to realize the safe communication of electric power VOIP system, and ensure the reliable transmission of voice and vid- eo in electric power intercom, a security terminal in electric power VOIP system based on DSP is designed. The security terminal includes software system and VOIP security communication platform. In the design of hardware, the （）MAP--1.137 DSP processor is the kernel of hardware, and the assistant processors, including security chip and noise resource chip, implement the secret key algorithm, and the authen- tication mechanism of intellectual card ensures the validity of user＇s identity. In the design of software, data frame format of communication between telephone module and safety module is defined, the alternant method of media flow in the system is introduced, a secret key consult algorithm based on mutual authentication and identity sign is put forward. Through the system testing, the results demonstrate that the data processing speed of VOIP security terminal is 52. 312Mbps, which meets the demands of real--time intercom communication in electric power system, the average time consumption in phase of secret key consult is 627ms, the conversion efficiency between exoteric communication and secret communication is high, the voice in network video communication between security terminals is vivid, the video image have not obvious distortion. The expansibility and transplant ability of the terminal are strong, so it has good application value.