Push the limit of wireless network capacity: a tale of cognitive and coexistence

Understanding the asymptotic network capacity has been one of the heavily investigated research problems that are instrumental to network design and planning. The majority of the past efforts has been focusing on a single technology network without dynamic channel states and dynamic channel access. In this talk, we will discuss the potential impact of two new technologies (\ie, cognitive radio and coexistence of cross-technology networks) on some fundamental network performance limits. Providing predictable performance and understanding the performance limit have been extremely challenging because of the uncontrollable and hard-to-predict external disturbances and opportunities. In the first part of the talk, we will summarize recent results on designing zero-regret online channel access schemes for multihop wireless networks based on recent development of multi-armed bandits problem. Recently several novel solutions were proposed for cross-technology coexistence without intervening legacy systems. In the second part of the talk, we will summarize recent efforts on designing co-prosperity wireless networks. We mainly focus on protecting the low-power Zigbee networks from the nearby WiFi networks. Then based on the new paradigms of cognitive radio networks and cross-technology coexistence, we give a first try to mathematically model the multihop cognitive radio networks with online spectrum access, and model the coexistability of two networks. We propose to further investigate the network capacity under these two new paradigms.