U-LTE is a new wireless technology that is currently being developed by industry and academia to offer LTE service in unlicensed spectrum. U-LTE addresses spectrum shortage from 4G LTE cellular networks by allowing them to operate in unlicensed bands. To ensure fair spectrum sharing among different wireless technologies (LTE and WiFi in particular), a number of coexistence mechanisms have been proposed. These mechanisms operate in the time, frequency, or power domains to minimize potential adverse effects from LTE. Based on these mechanisms, a number of U-LTE standards are being developed by industry. In this article, we present recent advances in this exciting area by reviewing the state-of-the-art LTE/WiFi coexistence mechanisms and show how they are incorporated into industry standards. We also point out several key challenges and open problems for future research.

中文翻译：

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免授权频谱中 LTE/WiFi 共存的最新进展


U-LTE 是一种新的无线技术，目前业界和学术界正在开发，以在非授权频谱上提供 LTE 服务。 U-LTE 允许 4G LTE 蜂窝网络在未经许可的频段上运行，从而解决了 4G LTE 蜂窝网络的频谱短缺问题。为了确保不同无线技术（特别是 LTE 和 WiFi）之间公平的频谱共享，人们提出了多种共存机制。这些机制在时域、频域或功率域中运行，以最大程度地减少 LTE 的潜在不利影响。基于这些机制，业界正在制定多项U-LTE标准。在本文中，我们通过回顾最先进的 LTE/WiFi 共存机制来展示这一令人兴奋的领域的最新进展，并展示如何将它们纳入行业标准。我们还指出了未来研究的几个关键挑战和开放问题。