atellite service is used to transmit TV, movies, and data signals to Wi-Fi access points on airplanes. These satellites operate on the higher-frequency K band at 17.3-31.0 GHz spectrum. This enables them to support the high bandwidths required for on-demand services. www.TechnicalPDF.com There is essentially a Wi-Fi router with an antenna located on top of the airplane's fuselage. The antenna is protected by a 4-inch to 1/2-inch thin case called a radome. Wi-Fi antennas within the plane distribute signals to passengers' devices in the aircraft's cabin. Satellite providers with these higher-frequency satellites also market their services to rural areas for Internet access. Companies that provide entertainment and data services on airplanes include Gogo, Inmarsat Plc, iPass, Panasonic, and Viasat. The challenge in providing data service in an airplane is the fact that both the airplane and the satellite travel at high speeds. This means that the airplane antenna must maintain contact with satellites that are also moving. Satellite providers with these high-frequency satellites also market their services to rural areas and developing countries that have limited or no cable TV service. Dish Network and AT&T-owned DirecTV distribute television signals in rural areas where cable TV is not available. These services are prone to disruptions in heavy fog. APPENDIX Table 7-5 Mobile Services Worldwide Technology Frequencies Features Comments Second- Generation Cellular Service Digital UL: 824MHz to Digital CDMA, TDMA, cellular 849MHz service GSM, and service with more iDEN are (CDMA, DL: 869MHz to capacity digital cellular Time- 894MHz air interfaces. Division analog Multiple service. www.TechnicalPDF.com Access Provides [TDMA], advanced Global features System for such as Mobile caller ID Communicati and Short ons [GSM] Message Service Integrated (SMS). Digital Enhanced Network [iDEN]) Personal UL: 1.85GHz to PCS refers to Communicati 1.91GHz added higher- on Service frequency (PCS) DL: 1.93GHz to digital 1.9GHz 1.99GHz spe