Truthful auction mechanism design for short-interval secondary spectrum access market

With the emergence of dynamic spectrum access technology and quick growth in demands for broadband mobile access, exploitation of short-interval spectrum availability offers an opportunity to better utilize spectrum. A short-interval secondary spectrum (SiSS) market is proposed in this paper, where a Mobile Network Operator (MNO) rents out multiple units of homogeneous spectrum units to Mobile Virtual Network Operators (MVNO) on a short-interval basis via a SiSS broker. The mandated SiSS broker not only presides over the trading but also manages an online database which is significant to the communication between MNO and MVNOs. For the purpose of efficient trading, we adopt the Vickrey-Clarke-Groves (VCG) auction as the basis to design a truthful SiSS auction. There are a few innovations. The first is a highly expressive cumulative bidding format, which allows maximum bidding options to MVNOs and eliminates the need for iterative bid refinement. The second is incremental bid constraint with reserve price to ensure bid per unit higher than the reserve price. Thirdly, an iterative allocation and payment calculation is so designed that per unit payments of winning MVNOs are higher than the reserve price set by MNO while maintaining the VCG merit of truthful bidding. A rational MNO is thus incentivized to put lowly utilized spectrum units for rent. Preliminary numerical experimentation demonstrates that the truthful SiSS auction generates to MNO in average 23% higher revenue per spectrum unit than the VCG auction. Computation time for broker to clear the auction is within 10 seconds for up to 50 bidders and 200 spectrum units, which suits SiSS applications.