Cognitive wireless networks benefit from context awareness which is integrated in decision making process in different layers. In this paper, we modify the MAC layer transmission permission probability, for elastic traffic users, in such a way to discourage the transmissions from/to the users at the border of the cell where transmissions cause significant interference in adjacent cell. This will be referred to as spatial traffic shaping. By using the absorbing Markov chain theory, we provide, for such a concept, analytical models to analyze system performance, mainly probability of successful channel assignment and message delivery delay. The analysis shows that in the cellular network, with channel spatial reuse factor equal to one, the probability of successful channel assignment close to one can be achieved with acceptable message delivery delay.