Date Added: Nov 2012
Cognitive Radio (CR) has been considered as a promising technology to enhance spectrum efficiency via opportunistic transmission at link level. The authors consider Opportunistic Spectrum Access (OSA) mechanism that takes into account packet delay and energy consumption. They formulate the OSA problem as a Partially Observable Markov Decision Process (POMDP) by explicitly considering the energy constraint as well as, the delay constraint, which are often ignored in existing OSA solutions. Specifically, they consider a POMDP with an average reward criterion. They further consider that the Secondary User (SU) may decide, at any moment, to use another dedicated way (3G) of communication in order to transmit its packets.