In response to an urgent requirement from PM-UAS, Bokler Systems Corp. (BSC) developed a Communication Relay System (CRS). The CRS is an in-band relay designed to integrate with the Shadow 200 UAV, and provide extended range voice and data communications to 125 kilometers via standard SINCGARS terminal equipment. The success and utility of the CRS was confirmed by its receipt of the US Army’s Research and Development Award in 2006, and its continued use in virtually all deployed Shadow 200 units.
Designed to be “transparent” to the end user, the CRS supports plaintext and ciphertext (CT) modes of operation. Further, CT operation does not require key material be loaded in the CRS radios, and therefore the design avoids any risk of loss of a keyed radio. When deployed aboard the Shadow 200 UAV, the CRS enables non-line-of-sight (NLOS) communication between Tactical Operation Centers, the Ground Control Station, forward area units and any other users on the same frequency or frequency-hopping network.
- Extensive modeling of RF link budgets using Longley-Rice
- Size and weight constraints
- Trade-offs between performance, cost and schedule
Formulate CRP Design Approach:
- In-band relay using off-the-shelf SINCGARS radios
- No keys required for CRP to support ciphertext mode CRP is “transparent” to end users
Develop CRP Design:
- Develop a small, efficient broadband VHF antenna
- Noise floor measurements of the Shadow 200 UAV
- Find and eliminate sources of RF interference on the Shadow 200
- Minimize weight and aerodynamic impact