Challenges and Progress in Transitioning from L/S Band to C-Band
Moving to a new band can be expensive, filled with experiments and developments for the telemetry community. The transition to C-Band for flight, launch and missile test applications in the USA is underway with different test ranges and organizations implementing new technologies at different rates. The challenges of reduced bandwidth, increased power and tracking issues are all being investigated and overcome. This white paper discusses the flight test community’s move to the C-Band spectrum, the current status, and how smoothly this transition is occurring.
The US Government has auctioned some of the airwaves for commercial mobile devices:
- 2 Blocks in the 1695-1710 MHz band
- 4 paired sets of frequencies at 1755-1780 and 2155-2180 MHz
Once a grace period is over, all telemetry for:
- Flight Test
- Missile Test
- Launch Vehicles
…will reside in C-Band in the contiguous United States.
New frequency bands were established for these applications:
- 4400 to 4940 MHz
- 5090 to 5150 MHz
- 5925 to 6700 MHz
Required Telemetry equipment upgrades:
- Ground software
Low-risk approach: use dual-band operation
- L or S-Band
Initial testing demonstrated an impact on Link Margin, caused primarily by cable and connector losses, tracking accuracies, and water vapor effects.
Platforms require additional RF transmitter power over what was needed for the L and S-Band. The average extra power needed is 25%
Higher gain coding schemes bring additional Link Margin, used for many years in the Launch and Space industry.
Advances in commercial RF devices can be used in telemetry applications, this results in lower costs, higher gain, and reduced size.
Curtiss-Wright supports the transition to C-Band with single and multi-band solutions to allow the dual-band usage as long as the grace period continues.
- Single, dual, and tri-band programmable transmitters
- 20, 50, and 400 Watt Transponders
- iNet Transceivers
- Receivers – both PCI and rack-mounted
Examples of where is C-Band in place:
- California: Edwards – China Lake – Pt. Mugu
- Maryland: Pax – Aberdeen
- Virginia: NASA Langley – Fort Eustis
- Florida: Cape Canaveral - Eglin
C-Band in Progress:
- New Mexico: White Sands Missile Range
- Texas: Fort Worth – Grand Prairie
Curtiss-Wright Single and Multi-band Products: