AT&T's 3 GHz Proposal Raises Questions: Ghosh

Industry officials continued questioning AT&T’s Wednesday proposal that calls for major changes in how 3 GHz, including the citizens broadband radio service band, is configured (see 2410090037). Monisha Ghosh, University of Notre Dame engineering professor and former FCC chief technologist, said AT&T's proposal leaves some questions unanswered. While in principle it’s “desirable to have high-power and low-power users separated by one boundary, the AT&T proposal doesn’t address how the existing Navy radars in the CBRS band will be protected” or “relocated and how spectrum sharing in 3.1-3.45 GHz will be implemented,” Ghosh told us, noting there are now 120 different kinds of radar in the band. Ghosh warned against drawing conclusions before the administration completes its study of the lower 3 GHz band called for in the national spectrum strategy. Moreover, Ghosh disagreed with AT&T that CBRS is "underutilized.” Relocating CBRS devices into another band that’s not an existing 3rd Generation Partnership Project band wouldn’t be a “trivial” problem, she said. Meanwhile, Public Knowledge Senior Vice President Harold Feld wrote in an email, “When you have a hammer, everything looks like a nail,” and when you’re a carrier “everything looks like it should be optimized for mobile broadband.” Feld added, “CBRS was designed to permit new kinds of innovation by different actors, such as stadiums, large warehouses, ports, or enterprise customers looking to run their own private networks.”