TODA: Truthful Online Double Auction for Spectrum Allocation in Wireless Networks

The spectrum usage by a secondary user often happens in a certain geographical region and in a certain time interval, and the requests often come in an online fashion. Considering the selfish behaviors of primary users and secondary users, it is imperative to design online double spectrum auction methods. The most significant challenge is how to make the online double auction economic-robust (truthful in particular). Unfortunately, existing designs either do not consider the online requests or become untruthful when applied to scenarios when both primary users and secondary users could be selfish. In this paper, we address this problem by proposing TODA, a general framework for truthful online double auction for spectrum allocation. We assume that there is a central auctioneer, and the arrivals of secondary users' requests follow Poisson distribution. Upon receiving online spectrum requests, the central auctioneer will decide immediately which secondary and primary users will win the auction, and match winning primary users and secondary users, as well as decide how much secondary users should pay and primary users should get. To preempt existing spectrum usage is not allowed. We study the case in which the conflict graph of secondary users is a complete graph, which occurs in the urban area where the distribution of the secondary users is very dense. In this case, we design strategyproof (truthful) mechanisms for both the primary users and secondary users. To the best of our knowledge, we are the first to design truthful online double auction mechanisms for spectrum allocation. Our simulation results show that the expected social efficiency ratio of our mechanism is always above 80% compared with the off-line VCG mechanism and the spectrum utilization ratio is around 70% when the system is highly loaded.