S-band and Ku-band return service interference between TDRSS users

The Tracking Data Relay Satellite System (TDRSS) return service performance can be degraded by interference from another user when two or more spacecraft communicate with the same Tracking Data Relay Satellite (TDRS) at the same time. This paper describes the S-band and Ku-band return service self interference environment expected in the 1996 - 2010 timeframe and shows the self-interference expected for selected TDRSS users based on Communications Link Analysis and Simulation System (CLASS) Automated Conflict Resolution System (ACRS) and Interference Monitor (IM) tools. The results show: which user links are susceptible to interference from other users, the interference statistics, and whether or not interference can be avoided with appropriate interference mitigation techniques such as scheduling, cross-polarization, or Pseudo random Noise (PN) spreading. The analysis results enable Space Network (SN) managers to determine the impacts of self-interference on the TDRSS service availability. They also enable project offices to determine whether they should select return service communications parameters, such as polarization and PN spreading, to minimize the probability of being impacted by self-interference; try to schedule TDRSS support around other user spacecraft communications schedules; or accept communication outages due to self-interference.