  Cognitive radio technology offers an important function in the efficient
utilization of the radio spectrum. Besides, it is expected that CR-enabled
vehicular ad-hoc networks (CR-VANETs) enrich the communication performance of
the existing vehicular networks (VANETs). However, to ensure efficient
performance in a multi-hop communication, the routing protocol in CR-VANETs
needs to consider the autonomous mobility of the vehicles as well as the
stochastic availability of the channels. Hence, this paper introduces a
spectrum-aware mobility pattern based reactive routing protocol for CR-VANET.
The proposed protocol accommodates the dynamic behavior and selects a stable
transmission path from a source node to the destination. Therefore, the
proposed protocol is outlined as a weighted graph problem where the weight for
an edge is measured based on a parameter termed as NHDF (Next-hop Determination
Factor). The NHDF implicitly considers mobility patterns of the nodes and
channel availability to select the optimum path for communication. Therefore,
in the proposed routing protocol, the mobility pattern of a node is defined
from the viewpoint of distance, speed, direction, and node's reliability.
Furthermore, the spectrum awareness in the proposed protocol is measured over
the number of shared common channels and the channel quality. It is anticipated
that the proposed protocol shows efficient routing performance by selecting
stable and secured paths from source to destination. Simulation is carried out
to assess the performance of the protocol where it is witnessed that the
proposed routing protocol outperforms existing ones.
