what is your opinion on digital modulation, multiplexing techniques and high-speed data transmission? Give an explanation to the questions. What modulation standards other than QPSK are there? What type of modulation do dial-up modems use? What type of modulation do cell phones use? How can data be "compressed" to allow faster transmission? How data can be encrypted to stop people from stealing the data over a wireless transmission? What ways exist to multiplex (combine several channels onto one) data for transmission over a high-speed channel?