  In vehicular ad hoc networks, the dynamic change in transmission power is
very effective to increase the throughput of the wireless vehicular network and
decrease the delay of the message communication between vehicular nodes on the
highway. Transmission range is directly proportional to the transmission power
the moving node. If the transmission power will be high, the interference
increases that can cause higher delay in message reception at receiver end,
hence the performance of the network decreased. In this paper, it is analyzed
that how transmission power can be controlled by considering other different
parameter of the network such as; density, distance between moving nodes,
different types of messages dissemination with their priority, selection of an
antenna also affects on the transmission power. The dynamic control of
transmission power in VANETs serves also for the optimization of the resources
where it needs, can be decreased and increased depending on the circumstances
of the network. Different applications and events of different types also cause
changes in transmission power to enhance the reach-ability. The analysis in
this paper is comprised of density, distance with single hop and multi-hop
message broadcasting based dynamic transmission power control as well as
antenna selection and applications based. Some summarized tables are produced
according to the respective parameters of the vehicular network. At the end
some valuable observations are made and discussed in detail. This paper
concludes with a grand summary of all the protocols discussed in it.
