company's customer has his own computer at the hosting company. High-speed Carrier Gigabit Ethernet capacity lines connect the hosting company to the Internet backbone. Companies often remotely upload or download information to their host-located computer via Carrier Gigabit Ethernet. Online learning is an example of an extranet service. It provides web-like access to educational material for school staffs and students. This is an advantage to schools that offer it because it enables them to offer their courses to students that are not within commuting distance of the college or university. In addition to supplying extranet software, online-learning companies offer to host the application at their own site. www.TechnicalPDF.com 7. Mobile and Wi-Fi Networks In this chapter: Introduction Spectrum for Wireless Networks-A Critical Asset More Efficient 4th Generation Digital Networks LTE-The First True 4th Generation Cellular Protocol 5G Mobile Networks-Small Cells; Additional Capacity The Internet of Things-IoT Applications and Services Wi-Fi Standards, Architecture, and their Use in Cellular Networks Satellites-Geosynchronous and Low Earth Orbiting Appendix INTRODUCTION Mobile devices are a central part of many people's lives. This is especially true of young people. When graduate students at a university were asked if they agree with the following statements, the majority of them agreed. You wake up in the middle of the night to check your phone. You check your smartphone within 10 minutes of going to sleep at night. You check your smartphone within 10 minutes of waking up every day. You study at cafes, and check your WeChat or Instagram accounts there You play games on your phone at the subway. You check for messages while walking to class. Some students stated that they check their phones 15 and more times every hour. Young people and not-so- young people use their phones for online gaming, video streaming, and social networks. It's an integral part of their day. High usage is not confined to teenagers and twenty