Mutual interference evaluation in cognitive radio networks with log-normal shadowing

The always increasing need of wireless access networks has risen up a question about the spectrum usage efficiency. It has been demonstrated that the traditional assignment schemes, do not work well in terms of spectral efficiency. The cognitive radio paradigm could solve the problem by allocating licensed spectrum portions to unlicensed users (secondary users) under particular restrictions. In this case, the mutual interference between primary and secondary users represents a critical aspect, which needs to be investigated. This paper describes a simple but effective model for evaluating the mutual interference problem, in a complex scenario with more than one primary transmitter, a multi-hop secondary network and a channel model affected by lognormal shadowing. Moreover this work presents how these information could be used in order to define a reliable routing metric for the secondary multi-hop network.