Group Buying Spectrum Auctions in Cognitive Radio Networks

Abstract

Spectrum has been sold at millions of dollars per megahertz through spectrum auctions. The staggering price hinders small network providers from becoming auction winners. Inspired by the group buying service on the Internet, group buying strategy has been introduced into the design of spectrum auctions to increase the buying power of small network providers. In this paper, we propose two truthful group buying auctions, namely, $\mathsf{TRUBA}$ and $\mathsf{TRUBA}^{+}$ , to take advantage of the collective buying power of secondary users (SUs) within each secondary network (SN). We carefully design the budget extraction for each secondary access point (SAP) within the SN to maximize the budget collected from the SUs. In addition, we allow the primary user (PU) to assign its channels strategically to boost the chance of successful transactions. These two features together empower $\mathsf{TRUBA}$ and $\mathsf{TRUBA}^{+}$ to significantly improve system performance, as compared with the existing group buying auction, in terms of the number of successful transactions (up to 16 times in the evaluation results), the number of winning SUs (up to 21 times), the average utility of the SUs (up to 19 times), and the utility of SAPs (up to 85 times). In $\mathsf{TRUBA}^{+}$ , the utility of the PU is improved by up to 44 times.