FIGURE 3.1 The regions as defined in Article 5 of the Radio Regulations. The shaded part represents the Tropical Zone. SOURCE: National Telecommunications and Information Administration, Manual of Regulations and Procedures for Federal Radio Frequency Management (Redbook), May 2003 edition, revised January 2006. See http://www.itu.int/ITU-R/ for more information.

Because regulations, allocations, and footnotes can change, the reader is advised to consult the National Telecommunications and Information Administration’s (NTIA’s) Manual of Regulations and Procedures for Federal Radio Frequency Management (Redbook) or the Federal Communications Commission’s (FCC’s) FCC Online Table of Frequency Allocations, as well as the Radio Regulations, for the latest information. The Redbook can be found at http://www.ntia.doc.gov/osmhome/redbook/redbook.html, and the FCC’s document can be found at http://www.fcc.gov/oet/spectrum/table/fcctable.pdf. The information given in this chapter is current as of January 2006.

Each of the following eight sections in this chapter begins with a table of allocations for a specified frequency range—allocations below 1 GHz (Table 3.1), between 1 and 3 GHz (Table 3.2), between 3 and 10 GHz (Table 3.3), between 10 and 25 GHz (Table 3.4), between 25 and 50 GHz (Table 3.5), between 50 and 71 GHz (Table 3.6), between 71 and 126 GHz (Table 3.7), and between 125 and 275 GHz (Table 3.8).

The first column of each table lists the band allocations, and the fourth column elaborates on the scientific use of each band. In the second column, primary allocations are shown in capital letters (e.g., “RAS”), and secondary allocations appear in lowercase letters (e.g., “ras”). Footnotes to the tables indicate where the allocations in other regions differ. Parentheses around a science service—for ex-