Bergmayer also praised an FCC proposal to update its "spectrum screen," a set of rules that prevent any single provider from gaining too large a share of the spectrum available in a particular market. The current scheme, he said, "treats all spectrum alike, even though some spectrum bands are better-suited to mobile broadband than others." As a result, he argued, it has become ineffective at preventing Verizon and AT&T from gaining enough spectrum to threaten competition. He urged the FCC to revise the rules to ensure the new auctions don't further entrench the dominance of the largest incumbents.