Abstract : Medical multimedia data transmission for remote diagnosis and emergency incident reports will significantly increase in the coming years. Thus, broadband network technologies with ability to be adaptable to user's context and application content must be considered. In this paper, we propose an on-the-fly resource reservation protocol for medical multimedia content delivery in cognitive radio networks. Our approach is based on an appropriate channels switching, that meets the need of end-to-end video quality and throughput requirements for better clinicians analysis. When a channel switching must be performed, an appropriate channel is reserved. This process will also rely on a signalling protocol which allows transmitting traffic characteristics and required network resources to all relay nodes for a best decision-making.