The paper is about a new routing protocol suggested for Cognitive Radio Networks (CRN) called Head Cluster IP Spectrum Aware Geographic (HC-IPSAG) and the associated performance. The protocol is an extension of the formerly advanced IPSAG routing protocol, for the case of larger CRNs. Splitting of the CRN domain into clusters is considered here. Each cluster is represented by a head node and the inter-cluster routing is done by using the IPSAG routing concepts within the virtual network created by the cluster head nodes. A CRN simulation model has been developed to study the performance of HC-IPSAG. Our results show that the protocol is performing well in the case of high mobility as well as the performance decreases with the growth of the cluster number.