The fifth generation (5G) cellular infrastructure is envisaged as a dense and heterogeneous deployment of small cells overlapping with existing macrocells in the Radio Access Network (RAN). Densification and heterogeneity, however, pose new challenges such as dealing with interference, accommodating massive signaling traffic, and managing increased energy consumption. Heterogeneous Cloud Radio Access Networks (H-CRAN) emerges as a candidate architecture for a sustainable deployment of 5G. In addition, the application of SDN concepts to wireless environments motivated recent research in the so-called Software-Defined Wireless Networking (SDWN). In this article, we discuss how SDWN can support the development of a flexible, programmable, and sustainable infrastructure for 5G. We also present a case study based on SDWN to perform frequency assignment, interference, and handover control in an H-CRAN environment. Results allow the establishment of a tradeoff between wireless communication capacity gains and signaling overhead added by the employment of SDWN concepts to H-CRAN.

中文翻译：

---

异构云无线接入网络中软件定义无线网络的设计注意事项

第五代 (5G) 蜂窝基础设施被设想为与无线接入网络 (RAN) 中现有宏蜂窝重叠的小蜂窝的密集和异构部署。然而，密集化和异构性带来了新的挑战，例如处理干扰、容纳大量信号流量以及管理增加的能源消耗。异构云无线接入网络 (H-CRAN) 成为 5G 可持续部署的候选架构。此外，SDN 概念在无线环境中的应用推动了最近对所谓的软件定义无线网络 (SDWN) 的研究。在本文中，我们将讨论 SDWN 如何支持为 5G 开发灵活、可编程和可持续的基础设施。我们还提出了一个基于 SDWN 进行频率分配的案例研究，H-CRAN环境中的干扰和切换控制。结果允许在无线通信容量增益和通过将 SDWN 概念应用到 H-CRAN 所增加的信令开销之间建立折衷。