Exploring vs exploiting: Enhanced distributed cognitive coexistence of 802.15.4 with 802.11

Thanks to recent advances in wireless technology, a broad range of standards are currently emerging. Interoperability and coexistence between these heterogeneous networks are becoming key issues, which require new adaptation strategies to avoid harmful interference. In this paper, we focus on the coexistence of 802.11 WLANs and 802.15.4 sensor networks in the ISM band. These networks have very different transmission characteristics that result in asymmetric interference patterns. We propose distributed adaptation strategies for 802.15.4 nodes to minimize the impact of the 802.11 interference. This interference varies in time, frequency and space and the sensor nodes adapt by changing their frequency channel over time. The proposed strategies use adaptive simulated annealing and find a proper balance between exploration and exploitation.