Abstract: The influence of forward data access modes on the timedivision polling chainbuilt navigation constellation intersatellite link network data interchange mechanism and communication performance was analyzed, based on which the evaluation and suggestion for the current forward data access application were given. Firstly, the satellite-satellite-station data interchange mechanisms of the quickest path and the fixed node forward data access modes were analyzed, and the corresponding topology and routing planning strategy were given. Secondly, based on the data processing models and typical simulation scenarios of the Walker 24/3/1 global navigation constellation and stations, the simulation and analysis of communication performances of capacity and transmission delay was carried out on the quickest path and the fixed node access modes, and the characteristics of network communication performance and data congestion on the two modes were compared. It is concluded that the quickest path mode has obvious advantages over the fixed node mode in communication performance. Lastly, the advantages and prices for application of the two data interaction mechanisms were evaluated, and the suggestion on proper application of the fixed node forward data access mode was given under the conditions of low communication capacity, low communication delay and high reliability.

Key words: forward data access, data interaction mechanism, navigation constellation, intersatellite link, communication performance