通信英语 LESSON07.ppt

Unit 7 WDM Contents Revision . Pre-reading Activities While-reading Activities New words and phrases Text organization Text and translation Post-reading Activities Further Development of the Theme-related Specialized Knowledge Assignments Revision 1. What have we studied in the Unit 6? Possible answers: SDH 2. What is SDH? Possible answers: SDH is an International Standard for high-speed synchronous optical telecommunication networksa Synchronous Digital Hierarchy. 3. Tell us the main application of SDH? Possible answers: The SDH signal is capable of transporting all the common tributary signals found in todays telecommunication networks. Pre-reading Activities Ask the Ss the following two questions related to the theme of the text: Can you enumerate what you contacted in the study of the courses including optical communications? Possible answers: optical fiber, OA, FTTB, FTTO, FTTN, FTTH, etc. What is the application of optical fiber? Do you know anything about WDM? Possible answers: optical fiber is a transmission medium through which numerous signals are transmitted , it can be used to build optical networks . Wavelength Division Multiplexing (WDM) enables the utilization of a significant portion of the available fiber bandwidth by allowing many independent signals to be transmitted simultaneously on one fiber, with each signal located at a different wavelength. (The Ss might be encouraged to discuss this topic before class either in English or in Chinese.) While-reading Activities / New words and phrases visionary [vi??ｎ?ri] n. 幻想家，梦想家 contribute [k?ntribjut] v．捐献，贡献 significant [signifik?nt] adv. 重大的，效果显著的，具有特殊意义的 property [pr?pr?ti] n.所有物，房产，所有权 fundamental [f?nd?mentl] adj. 基础的，重要的，本性的 span [sp?n] v.跨过，延伸 twinkle [ twi?kl] v.闪烁，闪耀，眨眼 equivalent [ i kwiv?l?nt] adj．相同的，同等 traffic [ tr?fik] n.交通，通信量，交易 ample [?mpl] adj.充足的，充分的，宽敞的 evidence [evid?ns] n.证据，证词 phenomena [fin?mino] n. 单数为phenomenon n. 现象 While-reading Activities / New words and phrases u