To keep supporting next-generation requirements, the radio access infrastructure will increasingly densify. Cell-free (CF) network architectures are emerging, combining dense deployments with extreme flexibility in allocating resources to users. In parallel, the Open Radio Access Networks (O-RAN) paradigm is transforming RAN towards an open, intelligent, virtualized, and fully interoperable architecture. This paradigm brings the needed flexibility and intelligent control opportunities for CF networking. In this paper, we document the current O-RAN terminology and contrast it with some common CF processing approaches. We then discuss the main O-RAN innovations and research challenges that remain to be solved.

翻译：为了不断支持下一代需求,无线电接入基础设施将日益密集。无细胞网络结构正在出现,将密集部署与向用户分配资源的极端灵活性结合起来。与此同时,开放无线电接入网络模式正在将RAN转化为一个开放、智能、虚拟化和完全互操作的架构。这一模式为CF网络提供了所需的灵活性和智能控制机会。我们在本文件中记录了O-RAN目前的术语,并将其与一些共同的CF处理方法相对照。我们随后讨论了O-RAN创新和研究方面尚待解决的主要挑战。