1. What does a filter do and why is one needed in a radio system?(250-600 words) 2. What is the purpose of a mixer? Include a discussion of sidebands in your answer.(250-600 words) 3. Compare and contrast the multiplexing techniques TDMA and FDMA in the area of wireless networking? (250-600words) 4. A local engineering group ask you to present the merits of different antenna, such as dish, yagi, and horn antennas. Research these technologies in details and pay specific attention to how they are used as well their strengths and weakness. Provide an opinion regarding which antenna types will become the dominant players in the future of medium- and long-distance wireless links. Please submit power point slides in your answer. (12 slides) 5. How does the WiMAX privacy sublayer provide security for a WiMAX network? (250-600 words) 6. How does CSMA/CA in DCF handle media contention? (250-600 words) 7. Telestra is a company that is licensed to provide wired telecommunication services in Australia. The company has contracted Exetel to assist it with the selection and implementation of a new field service system. The goal is to provide service technicians with wireless access to the corporate network and a vast electronic library of technical manuals and schematic diagrams, which would reduce or eliminate the need for staff to carry a large number of books and drawings, especially while servicing equipment underground or when climbing on transmission towers. In addition, this means that the technicians would be able to immediately read and update the records for all the equipment, thereby avoiding massive amounts of paperwork as well as potential errors and omissions. However, the company is having trouble deciding on which technology to adopt- handheld cellular, tables with 3G or 4G access, or notebooks equipped with cellular cards. Exetel has asked you to help. - Create a presentation outlining the advantages for Telestra of using digital cellular handsets or cellular wireless cards. Determine the ability of the smaller cellular handsets (as opposed to notebook computers, which may be difficult to carry everywhere) to display standard PC documents such as Word, Excel, and PDF files, and evaluate how this could help the company. Because the group you will be presenting to is composed of nontechnical manager, be sure your presentation is understandable by both technical and non-technical personnel. Limit yourself to a maximum of 15 PowerPoint slides.