Although studies on CRAHNs are ongoing, work related to cognitive link state-based routing has been limited.
Although OLSR is a potential candidate for tactical MANETs, it has certain intrinsic problems when applied to CRAHNs.
CLSR is a proactive routing protocol based on OLSR, but is modified to operate properly in CRAHNs.
In this paper, we proposed the CLSR protocol for tactical CRAHNs.
In this case, some salient characteristics of CRAHNs, which seriously deteriorate TCP performance, include the vulnerable shared media access due to opportunistic access, and the frequent route breakages due to PU arrivals, etc.
They used the extended version of the NS-2 to evaluate various TCP versions such as TCP Reno, New Reno, Vegas and Sack in CRAHNs by considering the impact of three factors on different TCP variants: (i) spectrum sensing cycle, (ii) interference from PUs and (iii) channel heterogeneity.
40] first proposed a novel spectrum switching detection scheme for CRAHNs in which intermediate nodes monitor the variation of the RTT and the arrival interval time of packets to detect the spectrum switching over succeeding links.
51] proposed a comprehensive end-to-end congestion control framework in CRAHNs considering the non-uniform channel availability.
In fact, there are still many research open issues on CRAHNs that remain to be solved .
The proposed protocol, which is an extension of AODV protocol , offers routing solutions and fault tolerance in CRAHNs.
In , a tree-based protocol has been proposed for CRAHNs based on assumption that all nodes are fixed or move very slowly.