The mistakes in the spectrum management have drive to a problem of the scarcity of spectrum,
which can be solved through the use of Cognitive Radio (CR) technology. The main concept of CR
technology allows unauthorized users (secondary users (SUs))for using the spectrum resources for
communication without harm authorized users (primary users (PUs)).The traditional wireless networks,
the nodes are connected based on a centralized infrastructure. But in Cognitive Radio Ad Hoc Network
(CRAHN) Networks, mobile SUs nodes are connected to each other without a central infrastructure.
Routing in CRAHNs is an important and necessary process in CRAHNs. It faces many and various
challenges. These challenges include PUs intervention, frequently dynamic topology, energy
consumption problems, unavailable channels, and fragile connections between nodes. The our probased
routing protocol called A tree routing protocol for cognitive radio network (C-TRP) has utilized the tree
routing algorithm with a spectrum management module in one routing decision module. In this paper,
weevalute a performance of the tree routing protocol (C-TRP) under the influence of the different PUs
activity patterns with help of three performance metrics :hop count, the number of CR nodes and number
of available channels. The performance evaluation is evaluted using NS-2 simulator. Simulation results
confirm that C-TRP outperforms “spectrum-tree based on demand routing protocol for multi-hop
cognitive radio networks"(STOD-RP), and Cognitive Tree-based Routing(CTBR) in terms of packet
delivery ratio and causes less harmful interference to PR nodes, and also less end-to-end delay in all
primary radio nodes activity patterns.