Optimum Deployment of Communications Relays in an Interference Environment

The use of communications relays is examined as a means of improving the operation of line-sight-links in an interference or jamming environment. Expressions are derived that define optimum relay locations and the number of relays. These relationships are functions of the system and interference parameters, as well as of the link and interference source geometry. Bounds on flight path orbits of airborne relays are also defined. Backlink operation with and without relays is considered, and the condition for identical relay locations for both forward link and backlink data flow is derived. The results obtained can be used to evaluate tradeoffs among the different options for reducing vulnerability to external interference.