终端直通(D2D)是第五代移动通信系统的核心技术之一。由于其自身协作共享理念与终端用户自私性之间的冲突，D2D通信凸现出强烈的社会属性。本项目拟针对社会关系驱动的D2D通信技术展开研究。首先，从分析D2D通信存在的内部和外部矛盾入手，对D2D通信中面向局域、广域范围的社会关系属性以及细粒度隐私安全需求社会属性进行了建模。建模过程创新地使用了排队系统、滤波系统等模型，为分析相关社会关系属性的统计特性提供了理论工具。在此基础上，面向局域范围的社会关系属性，研究D2D链路互惠方案与基于节点中心性的D2D通信技术；面向广域范围的社会关系属性，研究信用驱动的D2D通信方案；面向安全需求社会属性，研究细粒度隐私属性驱动的两跳D2D传输方案和隐私-共享联合驱动的多源多目的下载方案。最后，开发仿真平台，验证所提创新理论和算法。本项目的开展将为D2D网络传输技术的发展与推广提供重要的理论依据和技术参考。

Device-to-device communication (D2D) is one of the key technologies of the 5G mobile communications system. Due to the contradiction between its essential spirits of cooperation/sharing and users' selfishness, D2D communications shows strong social features. This project plans to conduct research on social-aware D2D communications technologies. First, staring with analyses on inner- and outer- contradiction in D2D communications, model the local-area and wide-area oriented social features and the fine-grained privacy social feature. The modeling process inventively uses the queuing system, filter system, etc., which provides theoretical tools for analyzing the statistics of social-relation features. Based on these results, towards local-area social-relation features, study credit-driven D2D communications scheme. Towards wide-area social features, study social-aware D2D communications schemes. Towards the social relation of privacy requirements, study fine-grained privacy-driven two-hop D2D transmission scheme and joint privacy-sharing-driven multi-source multi-destination download scheme. Finally, the simulation platform will be developed to verify proposed innovative theory and algorithms. This project will offer important theoretical foundations and technical references for the development of D2D networking technologies in our country.