Interference Aware Medium Access for Dynamic Spectrum Sharing

We address dynamic spectrum sharing for future mobile communication systems where multiple operators share license exempt spectrum. In such an environment cognitive radios are needed that are able to sense, as well as dynamically allocate the available resources in a distributed manner and on a short-term basis. In this paper we propose dynamic spectrum assignment (DSA) based on busy burst (BB) signaling. Its basic principle is that receivers upon data reception transmit a busy signal in an adjacent time multiplexed minislot. Through exploitation of channel reciprocity, other potential transmitters are prevented from interfering by first listening to the busy signal. Due to its decentralized nature, the considered BB-DSA protocol appears to be ideally suited for dynamic spectrum sharing in license exempt spectrum.