28 Network Design and Engineering Guide 2010-10-26General Carrier DesignEssential SkyWAN ® Satellite Link Layer FeaturesFigure 2-8 TDMA Frame StructurePlease note: a ranging slot is allocated only when a station is entering the network.Transmit and Receive CarriersSkyWAN® stations receive data on one or two carriers (e.g. IDU7000 with two demodulatorboards) . These carriers are defined by station configuration and are referred to as ’HomeChannel One’ and ’Home Channel Two’.SkyWAN® stations can transmit data on any active carrier in the network (frequency or carrierhopping). By configuration the possible transmit carriers can be allocated (restricted) for eachstation.A TDMA frame plan for a SkyWAN® network with 8 carriers is displayed in figure 2-9. In thisexample carrier 1 and 2 carry a reference burst, carrier 3-8 only data bursts.Figure 2-9 Tx Frequency Hoppingi Restriction for master stations: Home Channel One must be carrier 1.In Dual Uplink Beam (DUB) modes Home Channel Two must be carrier 2.
