However, these activities can be viewed as two facets of the same field, and together they have undergone substantial development over the past ten years.
#facet n. 面；方面；小平面 vt. 在…上琢面 #undergone v. 经历(undergo的过去分词) #substantial adj. 大量的；实质的；内容充实的 n. 本质；重要材料
One important but underlying reason for the wide attentions for SDN lies in that SDN is just a paradigm, rather than an ossified architecture.
underlying reason 根本原因 paradigm n. example, model ossified adj. 保守的、冷酷的、僵化的
As a result, SDN has been applied or extended to various scenarios, such as data center networks, network security, optical networks, and naturally, mobile and wireless scenarios studied in this paper.
scenario n. 场景 .pl. scenarios scenario analysis 情景分析