In the ad hoc networks, nodes create dynamic topologies, with very limited resources, such as bandwidth and energy. In much the same way as other routing protocols, the Ad Hoc Cognitive Packet Network (AHCPN) conventionally applies a fixed transmission power, which is able to achieve reliability in links' connectivity. In this paper, we propose a power control algorithm, namely, the adaptive Distributed Power management algorithm (DISPOW), devised as a network-assisted functionality of ad hoc cognitive packet-based routing. The proposed routing protocol is based on an adaptive, per packet, transmission power control scheme. In which a certain target of Signal to interference plus noise ratio (SNIR) value and Quality of Service (QoS) is maintained. This scheme is concerned with realising path loss of signal through drawing a comparison between the power that is transmitted, which is in the header of the packet, against the power that is received by a certain node. The signal power required for achieving a reliable link transmission to each of the neighbour nodes is calculated and preserved within the packet header through each packet exchange process between any adjacent nodes. The power control algorithm DISPOW is to ensure energy consumption conservation, network connectivity, and a lesser degree of interference. Simulation results in network simulator 3 (NS-3.24) show that the proposed routing protocol overcomes the previous one in terms of Delay by almost 27%, Throughput by around 13%, Packet loss by nearly 9%, and Energy consumption by almost 40%.