工学 通信系统 释 public switched telephone network，PSTN 公用交换电话网 进行交互型话音通信、开放电话业务的公众网。是一种全球语音通信电路交换网络。
网络与数据通信 协议体系与组成结构 释文 public switched telephone network 公用交换电话网
- Sidibala Emperor Yingzong of Yuan Dynasty
- sidicon
- siding
- siding line
- Siding Spring Observatory
- Sidi Toui National Park
- Sidney Altman
- Sidney George Holland
- Sidney Gilchrist Thomas
- Sidney Hook
- Sidney James and Beatrice Webb
- Sidney Lanier
- Sidney Mintz
- Sidney Nolan
- Sidney Poitier
- Sidon
- Sidonie-Gabrielle Colette
- Sidon sequence
- Sidon set
- SIDS
- Sidu
- sidu
- Siduchishui Museum
- Sidun
- Siedentopf crater