This course will enable students understanding data communications concept, identifying the basic components of a data communications system, and representation and flow of data. The course focuses on the physical layer of the network, transmission medium properties and tasks must do, and services provided to the next layer; the data link layer. Students will identify data types and signal types representing data, signal properties in time and frequency domain, and the relationship between bandwidth and data rate, channel type, and transmission impairments, and their effect on the limited data rate according to Shannon formula. Students will identify also different line coding techniques, used to transport data after representing it by digital signals having different characteristics, to be suitable to the transmission channel, and finally using block coding and scrambling techniques to improve the performance of the data communications system. This course will also provide students with the basic techniques of analog-to-digital conversion, especially pulse code modulation, delta modulation, and related topics like digitization, Nyquist theorem, sampling rate, and quantization. Finally, serial and parallel transmission types will be represented.