SPA: Almost Optimal Sequential Channel Sensing, Probing, Accessing in Cognitive Radio Networks

In this paper, the authors address the spectrum utilization problem in Cognitive Radio (CR) networks, in which a CR can only utilize spectrum opportunities when the channel is idle. One challenge for a CR is to balance exploring new channels and exploiting existing channel, due to the fact that the channel availability and channel quality, potentially heterogeneous and time-dependent, are often unknown in advance due to the large number of channels, and the limited hardware capability of single CR. In this paper, they propose practical joint sensing/probing/accessing schemes, which determine when to sense, probe and access spectrum opportunities.