I. Revision mins com Teacher uses the following exercise to help the students to revise the important expressions or phrases

1. what have we learned in the Unit projector, Possible answers: cellular Mobile Telephone System 2. What is cellular Mobile Telephone System? loud speaker Possible answers: to reuse the allocated frequency band in different geographic locations blackboard

1.to know the development of switching techniques Teaching 2.to understand the main ideas of the text Objectives 3.to master the useful sentence structures, words and expressions used in the relevant exercises

1. to know The Development of Paging System Teaching 2. to understand the construction of paging system Objectives

1. to know the operation and advances of WDM and optical network Teaching 2. to understand the main idea and organization of the text; Objectives 3.to master some important new words, phrases and their

1. to know the operation and application of sDh eaching 2. to understand the main idea and organization of the tex Objective

1. to know the origin and development of Internet Teaching 2. to understand the main idea and organization of the text

1. to know the transmission media of data signals, the structure of full-duplex data transmission system and its peration and the coding of data signals 2. to understand the main idea and

1. to know the three basic processes of PCM: Sampling Quantizing Encoding Teaching 2. to understand that PCM is the heart of technology in communications in Objectives

1. to know the origin, operation and disadvantages of asynchronous serial data transmissioneaching 2. to understand the main idea and organization of the tex Objective