Tong, Lang Cornell University - Endow
This research aims to develop novel random access techniques for two emerging wireless applications: high data-rate wireless LAN for hot-spot access and information extraction in large-scale and low-power sensor networks. For both applications, conventional medium access control that assumes simplistic channel model is one of the major performance bottlenecks The investigators explore new cross-layer design strategies by exploiting tight interactions between signal processing at the physical layer and the medium access control sublayer. The research has two major themes. The first involves developing optimal medium access strategies that capitalize the multi-packet reception capabilities of the physical layer and provide capacity achieving random access. Signal processing techniques are developed to maximize the stable throughput of users. Rate allocations, quality of service requests, and pricing structures are designed based on the characterization of the capacity and stability region of optimal random access protocols. The second theme focuses on low power and energy efficient random access for large-scale sensor networks. The cross-layer design approaches take the form of utilizing channel state information at the physical layer. Distributed, scalable random access protocols with low complexity are investigated for th e sensor reach-back problem. Novel signal processing techniques at the sensor node and the mobile access point are developed for energy efficient medium access.
