 a 700MHz block in 2008 to a variety of carriers for higher-capacity, higher-data-rate services. Verizon Wireless won regional licenses to spectrum in the A and B Blocks, and AT&T Mobil- ity won rights in the B and C Blocks. AT&T's B Blocks are in a different region than Verizon's. None of the licenses cover the entire country. The auction raised $19 billion for the federal government. All of the auction winners are required to use this spectrum to build networks capable of supporting higher-speed data on next-generation LTE networks. Using Numeric Designations for Roaming Compatibility In addition to alphabetic designations for blocks of spectrum, numeric ranges are des- ignated for particular portions of spectrum within blocks. Standards bodies designate the numeric bands of spectrum for uplink and downlink transmissions. Uplink trans- missions are those from subscribers to carriers' antennas, and downlink transmissions are those from the carrier to the subscriber. The goal is to enable equipment compat- ibility SO that carriers can more easily make roaming agreements with one another. Mobile devices have preset designations for which frequencies are used for uplink and which are used for downlink communications. Thus, they only work on networks that use these same frequencies. Mobile and Wi-Fi Networks These bands are specified by numerals. For example, the 3rd Generation Part- nership Project (3GPP) designated band 13 spectrum of the 777-787MHz range for uplink transmissions. The 3GPP specifies other bands, such as 12 and 17, for either uplink or downlink transmissions. Not all technologies require separate frequencies for uplink and downlink communications. In these instances, numeric designations are not required. The 3GPP established third-generation Wideband Code-Division Multiple Access (WCDMA) standards, and some LTE standards. It is in the process of agreeing on additional LTE standards for voice and data. Using Auctions to Allocate Spectrum Because it is finite and critical to industry, security, and 