With the rapid development of communication networks, the information interaction between heterogeneous networks such as the Internet of Things (IoT) and vehicle ad-hoc networks (VANETs) is becoming more and more common. In cellular networks, the proximity devices may share files directly without going through the eNBs, which is named Device-to-Device (D2D) communications. It has been considered as a potential technological component for the next generation of communication. The traditional centralized network architecture cannot accommodate such user demands due to heavy burden on the back-haul links and long latency. Cyber-social networks seamlessly integrate people’s daily lives and social activities, which has a prominent contribution to the social relationship of mobile users in D2D communication. In this paper, we make an exhaustive review on the state-of-the-art research efforts on D2D caching. We first give an overview of D2D helper selection, including the network frame, computing method, and social-aware attribute. Next, a comprehensive survey of issues on D2D helper selection is presented. Finally, open research challenges and future directions are presented as well.

中文翻译：

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在助手选择中对D2D缓存的详细审查

随着通信网络的快速发展，物联网（IoT）和车辆自组织网络（VANET）等异构网络之间的信息交互越来越普遍。在蜂窝网络中，邻近设备可以直接共享文件而无需通过eNB，这被称为设备到设备（D2D）通信。它被认为是下一代通信的潜在技术组件。由于回程链路上的沉重负担和较长的等待时间，传统的集中式网络体系结构无法满足此类用户需求。网络社交网络无缝集成了人们的日常生活和社交活动，这在D2D通信中对移动用户的社交关系做出了突出贡献。在本文中，我们对D2D缓存的最新研究成果进行了详尽的回顾。我们首先概述D2D助手的选择，包括网络框架，计算方法和社交意识属性。接下来，将介绍有关D2D助手选择问题的全面调查。最后，还提出了开放的研究挑战和未来的方向。