# X-band **Domain:** Radio / Space Communications **Doc Type:** Canonical Technical Node **Maturity:** Developed ## Definition **X-band** denotes a microwave-frequency range used in radar, satellite and space communications. Exact regulatory boundaries vary by context; the ST5 system used assigned transmit and receive frequencies within the band. ## Nexus Context The X-band link is the operational environment for the evolved ST5 antenna. [[articles/The Evolutionary Roots of Silicon Valley|The Evolutionary Roots of Silicon Valley]] includes it because “fitness” was not abstract beauty: it meant meeting specified radio performance, geometry and mission constraints. ## Continuity Context Communication substrate determines which information can cross a boundary and with what latency, error and energy cost. For distributed intelligence or remote embodiment, a channel's bandwidth and failure modes become part of the subject's effective body. ## Sources / Provenance - NASA ST5 evolved-antenna technical report: https://ntrs.nasa.gov/search.jsp?R=20040152147 - IEEE frequency-band terminology: https://standards.ieee.org/ ## See Also [[wiki/Evolved Antenna|Evolved Antenna]], [[wiki/Machine Mediation|Machine Mediation]], [[wiki/Latency|Latency]], [[wiki/Remote Embodiment|Remote Embodiment]]