## 1 Introduction
To construct a CDS for routing protocol, an algorithm with rules based on energy level and degree of nodes was proposed in Reference [14]. The authors of Reference [15] proposed an energy efficient and salable routing algorithm based on length of route and remaining energy for extreme emergency ad hoc communications. In Reference [16], the authors proposed an efficient flooding and repairing local route algorithm based on a stable connected dominating set in MANETs. In this algorithm, if a node has minimum velocity and maximum signal strength, it is selected as a dominator. Besides, several studies on the routing issue were presented as follows. In Reference [17], the authors proposed a distributed interference-aware relay selection (DIRS) algorithm for IEEE 802.11-based wireless networks with multiple source-destination pairs. Each source-destination pair selects best relay by using inter-node interference and channel statistics without the knowledge of topology information. In DIRS algorithm, inter-node interference can be minimized by optimising relay selection. In Reference [18], the authors proposed a new multi-channel MAC protocol to solve the channel assignment and medium access problems in an integrated manner. In this protocol, each mobile host was assigned a common channel for control purpose and it switched to remaining channels for data exchange. In Reference [19], the authors proposed an optimization methodology to analytically calculate the end-to-end throughput capacity of IEEE 802.11-based multi-hop wireless networks. The proposed methodology provided a very accurate calculation of the end-to-end throughput capacity by considering the node interference, the impact of hidden node collision and multi-rate terminals. In Reference [20], this article addressed a number of problems when implementing two routing protocols on actual wireless networks. There was no protocol which provided a stable multi-hop route. Based on the authors' experiences, several outlines are recommended for future work in MANET researches. Most of routing protocols in cognitive mobile ad hoc networks have recently considered in dynamic spectrum allocation and path establishment by observing primary user activity regions in Reference [21]. Layered graphs were utilized to model multi-channel networks [22] and colored graphs were deployed for model spectrum sharing and allocation problems [23]. In Reference [24], a cognitive ad hoc on-demand distance vector (CAODV) protocol was proposed based on the ad hoc on-demand distance vector (AODV) protocol. Both route formation and packet discovery of the CAODV avoids the affected region of primary user. Moreover, the CAODV applies joint path and channel selection at each forwarder to minimize the route cost. This protocol broadcasts the route request packet to neighbors on all the channels that leads to increase control overheads and reduce network life time. In Reference [25], the authors proposed a distributed prediction-based cognitive topology control (PCTC) scheme which is a middle-ware approach (between the cognitive radio module and routing). The PCTC uses cognitive link availability prediction to aware the affected region of primary users and to predict the available duration of links in CR-MANETs. The PCTC constructs efficient and reliable topology in order to reduce re-routing and improve end-to-end network performance. In Reference [26], the authors proposed a SEARCH routing protocol for CR-MANETs to find a route subject to minimum end-to-end delay from the source to the destination without affecting primary user activities. Aiming at improving network throughput and mitigating interference to primary users, various routing problems are formulated based on graph theory [27; 28; 29]. In particular, the authors of Reference [27] introduced a mixed integer non-linear programming to minimize spectrum usage and aggregate interference from cognitive users to a primary user.