Utilizing IEEE 802.16 for Aeronautical Communications

Within this sub-chapter an overview of the core functionalities related to data exchange are given. Overview physical layerThe Physical Layer (PHY) of the AeroMACS system shall be based on the OFDMA Physical Layer specification of the IEEE 802.16 standard with a channel bandwidth of 5 MHz.Thereby, the frame length shall be 5 ms.As the PHY will be based on the "Common part TDD profile" (WiMAX 2009), the Downlink and Uplink portions can vary dependent on the system settings (cf. Figure 2).The IEEE 802.16-2009 supports both Time Division Duplexing (TDD) and Frequency Division Duplexing (FDD) modes.However, AeroMACS shall be based on the TDD mode of operation.Reasons therefore are the dynamic allocation of Downlink (i.e. from Base Station to Mobile Station) and Uplink (i.e. from Mobile Station to Base Station) resources in order to efficiently support asymmetric Downlink (DL)/Uplink (UL) traffic, only a single channel is required which alleviates spectrum issues, and the TDD option is less complex.