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The issue of improving the bandwidth between air and ground has been addressed in several papers. Future bandwidth requirements per aircraft have been estimated to be in the region of 375 Megabits per second (Mbps) per 300 passenger aircraft (Buchter, 2012). An overhead of 25 Mbps could be added to account for aircraft telemetry and other aircraft (non-passenger) generated specific data giving an overall average bandwidth requirement of 400 Mbps per aircraft.
One proposed solution for an Airborne Communications Network (ACN) contains three main elements; photonic high capacity communications links, hybrid photonic/RF diversity networking and High Altitude Platform Stations based ACN to internet connectivity (Buchter, 2012). The proposed mesh solution uses laser ground stations to transmit information optically to balloons in the high atmosphere. From there the balloons would relay the data traffic via laser to the large aircraft.
Past implementations of airborne satellite platforms at L-band frequencies suffered from low-data rates, lack of available spectrum, and high costs. More modern satellite systems have been launched that use higher frequency parts of the spectrum band that have more available bandwidth as shown in Figure 1. These newer Ku- and Ka-band commercial satellite solutions help to eliminate the issues of the L-Band systems (Losada, 2011).
Figure 1. Satellite band plan (Maritime Telecom, 2014)
One of the main challenges that must be overcome in any airborne implementation is the fact that the antenna is on board an aircraft in motion, at speeds of up to 600 miles per hour. As the aircraft is moving dynamic re-pointing is necessary to track the satellite (Losada 2011). A Ku band antenna systems with a mechanically steered dish would have a dish diameter in the region of 0.65m, the antenna should track the satellite during movement of the aircraft at an angle speed of up to 25 degrees per second and have pointing error no more than 1 degree (Tyurin, 2007).